Thursday, October 31, 2019
Interpreter of Maladies, Symbols of Love Essay Example | Topics and Well Written Essays - 1000 words
Interpreter of Maladies, Symbols of Love - Essay Example The house triggers memories of the life they had together. It is a story of remembered and lost love. Shukumar and Shoba have taken to living separate lives in their own home. ââ¬Å"He and Shoba had become experts at avoiding each other in their three bedroom house.â⬠(Lahiri 1999, p7) This thought makes Shukumar remember how it was before. He used to look forward to the weekends, when they simply spent time together. They would look into each otherââ¬â¢s eyes and reach for each other, before they went to sleep. Their home started as a place where the couple spent time together and loved each other. They were expecting to start a family there. As Shukumar is preparing the evening meal he remembers the time Shoba would take care of the cooking. ââ¬Å"The pantry was always stocked with extra bottles of olive and corn oil.â⬠(Lahiri 1999, p9) He thought about how Shoba would always go to the market to make sure they had enough food in their home. Boxes and jars of food filled the room to the point they thought grandchildren would enjoy the treats waiting there. When friends would come by she would cook grand meals that seemed like she was cooking the entire day. Now Shukumar did the cooking. He used recipes that Shoba had, with hand written notes stating the date the couple shared the meal. Shoba, at one time, nurtured her home with food and friends. She made sure that there was more than enough. During this time the neighborhood is experiencing scheduled blackouts. The dynamic of their relationship changes as they share secrets in the dark. ââ¬Å"Something happened when the house was dark.â⬠(Lahiri 1999, p23) They started to talk, after months of virtual silence. They open themselves up to each other, eventually confessing their biggest secrets. Shoba plans to move into her own apartment. Shukumar confesses that he held their son, something she didnââ¬â¢t get to do. He promised that he would never tell her because of his love for her, but the last few days show that he
Tuesday, October 29, 2019
Greek tragedy Essay Example for Free
Greek tragedy Essay A view from the bridge was written by Arthur Miller in 1947. Arthur Miller uses a range of dramatic techniques effectively throughout the play to create tension and suspense, but particularly in the climax at the beginning of Act 2. These dramatic effects consist of; Stage direction, Greek tragedy, Foregrounding, Scenery, actions such as tension and climax and finally dramatic irony. In a view from the bridge, the central themes are, love, justice, family, the law and codes of honour. Together, they increase the characters development, so as an audience we empathise with the characters personal views, thoughts and opinions. Dramatic irony, is when the audience knows what is going to happen before the Protagonist is embedded within the text. An example of dramatic irony in the play is when Eddie returns home drunk whilst Catherine and Rodolpho are upstairs in the bedroom making love. This creates tension and suspense between the characters and also the audience, as we already know of Eddies hatred for Rodolpho because of Catherines loving feelings towards him. Arthur Millers use of the specific elements of a Greek Tragedy make the play extremely intense. The rules of a Greek tragedy consist of; A protagonist which dies at the end of the play The protagonist is clearly Eddie, as he is the central character and also sadly dies at the end of the play, he is brutally killed by Marco. A chorus is also needed in a Greek tragedy, The chorus explains and narrates the plot The chorus in the play is Alfieri as he is the commentator, he sets the scenes dramatically and also informs you what is going to happen in the upcoming scene/section. The protagonist is essentially good but his/her fate is sealed by a central flaws in character This is briefly reflected towards Eddie, as he was loving caring and protective over Catherine to start of with. He states-Now dont aggravate me Katie, your walking wavy! - This makes Eddie seem secretly obsessed with Catherine as it looks like Eddie does not want Catherine to grow up, by not letting her dress up like a normal eighteen year old girl would. Before the death of the hero, he has a moment of self understanding-Eddie gets stabbed by Marco in the end of the play, but before he dies he has a personal moment of self-understanding and forgiveness. Eddie, Beatrice and Catherine share their last goodbyes, publicly. Eddie finally states-My B! It sounds as if he wants her to forgive him for all the trouble and rebellion he has caused, Over something he could of easily let go of, but sadly didnt. This is an emotional time for the cast and audience as Eddies death was not expected, especially by Marco. The audience feels both empathy and dislike for the hero at different points. -At times Eddie can release anger, frustration and annoyance towards the audience and characters, by doing this Eddie loses his empathy from the audience. Eddie starts off with physical conflict with Rodolpho. This creates a lot of tension, with each scene of conflict becoming more intense than the one that preceded it. The tense atmosphere during the boxing scene at the end of Act One expresses Eddies secret jealousy towards Rodolpho, which results in Eddie releasing his frustration by physical violence. Eddie fires at Rodolpho-You cant hurt me [Rodolpho more seriously, jabs at Eddies jaw] The audience will not approve if Eddie interfering in Catherines and Rodolphos relationship which includes physical tension. There are also times when the Audience empathise with Eddie, as he is being loving and caring and trying to do the right thing, whereas Catherine acts selfish and ignores him. The character Alfieri has a very important role in the play A view from the bridge. Alfieri acts both as a narrator and commentator but his main function is to offer ideas to the audience to set them thinking about the message of the play. Alfieri also divides each act into unofficial scenes, and inform the audience on any missed action. Alfieri is a character in the play and yet his advice is objective and sympathetic. Alfieri is the first character to speak in the play; he therefore sets the scene and informs the audience the background to the action. He is a lawyer but in this area of Brooklyn the people distrust the law, he tells us-A lawyer means the law, and in Sicily, from where their fathers come, the law has not been a friendly idea since the Greeks were beaten. This speech immediately sets up tension between Alfieri, a representative of written law and the Italian immigrant community, who prefer to follow their own law. Alfieri understood Eddies love for Catherine was impossible to control. Alfieri empathised with Eddies in a way Beatrice could not. It aint nice Eddie This shows Beatrice confronts Eddie more than she actually Comforts him, whereas Alfieri states-Yes but those things have to end Eddie. This shows Alfieri understands Eddie psychologically whilst slowly and persuasively trying to steer him out of his unbearable dilemma. Stage Directions are very important in drama and this is evident in Arthur Millers A view from the Bridge. Stage directions give actors and directors character motivation and this allows actors to create believable characters and explain a characters actions and feelings. They also highlight characters emotions that are indirectly portrayed through stage directions, especially when describing the main focus of the play. , Eddie Carbone. In the beginning of act one, Catherine appeared to be an extremely friendly, confident little girl. I just got it, you like it? Catherine projects herself in this scene as a young, timid girl who does not have much knowledge of the outside world as she has been over-protected by Eddie all her life. [She turns for him]- Arthur Miller uses a variety of stage directions to develop Catherine as a character. The stage directions in the beginning of act one are secretly intimate and kind of shows a hint of sexual tension between Catherine and Eddie. [wipes her hand over her skirt]-Not many nieces do these flirty flexes with their uncles, but for Catherine this seems as it is normal to be twirling and flirting. When Rodolpho arrives, Catherine seems to be getting stronger and braver towards Eddie. She feels as if she is independent and superior. [She frees her arm, steps back into the bedroom] Catherine frees her arms from Eddie, Arthur Miler uses stage directions effectively in this section as it is building Catherines character from a Shy, inferior, tiny girl into a strong-minded, selfish, superior woman. This dramatically changes the audiences impression of Catherine. Catherine has always had an innocent fondness toward Eddie, but Eddie takes it the wrong way which makes their father and daughter relationship seem more sexual and possessive. [As she strives to free herself, he kisses her on the mouth] Eddie was obviously drunk when this stage direction was performed, but when your drunk your true feelings come out and Eddies passionate love for Catherine had finally been . sexually released. This had a massive impact on the audience as Arthur Miller created suspense in this section. Whilst Eddie is sexually obsessed over Catherine, Catherine just wants unconditional, parental love from Eddie and Romantic sexual love from Rodolpho. Catherine later bursts out Ill Kill you- If Catherine was secretly in love with Eddie like Eddie was with Catherine, she would have not threaten to kill him. When Catherine and Rodolpho are home alone, there is tension building up. Catherine starts curiously questioning Rodolpho, Suppose I wanted to live in Italy. She is testing his love for her, as Eddie had informed Catherine that Rodolpho is most l;likely using her just to be an American Citizen. Catherine refused to believe this but Eddie might of got the better side of her. Catherine later exploded with-You dont know, nobody knows! - This is showing Catherines neglect and isolation from Rodolpho and Eddie. She Presumes that no one understands her, but the audience thinks shes only confused as she does not know who to trust.
Saturday, October 26, 2019
Compare And Contrast Tcsec And Cc Information Technology Essay
Compare And Contrast Tcsec And Cc Information Technology Essay To evaluate a computer system or product to see it meets the security requirements based on the information security evaluation standards. Trusted Computer System Evaluation Criteria (TCSEC) was the first computer security evaluation standard which was published by the U.S. defense department in1985. TCSEC influenced other European countries and very soon some countries based on TCSEC to develop their own security evaluation standards. In 1996, America combined with 5 European countries (UK, France, Germany, Netherlands and Canada) and NSA (National Security Agency) and NIST (National Institute of Standards and Technology) developed a new criterion which was called Common Criteria (CC). In 1999 Common Criteria (CC) was recognized by ISO and named ISO/IEC 15408-1999. In this essay TCSEC and CC will be discussed, compared and contrasted to find out the similarities and differences and the strength of CC will be indicated. The answers for the topic are based on research on relevant articles and journals and most of the resources are from the internet. The materials are then analyzed and discussed. The outline of the report is as follows: Introduction- brief description of the topic. Background- explanation of TCSEC and CC. Compare and contrast the two standards Describe the similarities and differences between the two standards and state the advantages of CC. Some journals, articles and books are used in this report which can be found in the references. Background This session discusses TCSEC with the evaluation class of TCSEC. And also describes the CC and evaluation of assurance level of CC and the evaluation process. TCSEC Evaluation Class CC- Assurances Levels D Lowest protections EAL1 Functionally tested C1 Discretionary Protection EAL2 Structurally tested C2 Controlled Access Protection EAL3 Methodically tested checked B1 Labeled Security Protection EAL4 Methodically designed, tested, reviewed B2 Structured Protection EAL5 Semi-formally designed and tested B3 Security Domains EAL6 Semi-formally verified design and tested A1 Verified Protection EAL7 Formally verified design and tested Table 1- Evaluation Class of TCSEC and Evaluation Assurances Level CC TCSEC is commonly called the Orange Book (the cover of book is orange). TCSEC has 4 divisions and 7 evaluation classes. Each class contains security requirements and it is used to determine the level of trust of a computing system. The divisions of TCSEC are A, B, C, D and the seven evaluation classes are: D (lowest), C1, C2, B1, B2, B3 and A1 (highest). A is more secure than D, and 2 is more secure than 1. (See Table 1) Level D: non-secure system Level D only contains D1 evaluation class. D1 is the lowest protections and only provides security protection for file and user. Level D can be applied to any system which has been evaluated but did not meet the higher evaluation class requirements. Level C: Discretionary protection Level C provides audit trial protection and Level C includes C1 and C2.C1 is discretionary security protection and its class is lower in Level C. C1 provides discretionary access control and it has the responsibility for Identification and authentication. C2 has all the security features of C1 and has the function of audit trail and access protection. C2 requires single- user log-in with password and an audit trail system. C2 works through log-in process, security event and source isolation to increase access. Level B: Mandatory Control. There are 3 classes in Level B and they are B1, B2 and B3.B1 has all the requirements of C2 and it also has some new requirements: each object has a label which is under system control. It uses sensitivity labels as a basis of all the access control and labels the object which will import to the system. When the system administrator adds a new communication channel or I/O mechanism, he has to manually assign security level to the channel and mechanism. The system uses user password to determine the user access level and it also uses audit to record any unauthorized access [13]. B2 has all the requirements of B1. Besides that, the B2 administrator must have clear and documentation style of security policy for trusted computing base. B2 has some new security requirements: system must immediately inform any changes between user and associated network, only user is able to do initial communication in the trusted path and the trusted computer base supports inde pendent administrator and operator. B3 has all the requirements of B2. But B3 has stronger ability to monitor access and anti-interference. B3 system has to set the security of the administrator. The new security requirements for B3 are: provide a readable security list, some objects are not allowed for certain users to access, the system has to provide a description of the users and to identify user before any operation and the trusted computing base establishes security audit trail for each labeled object [13]. Level A has the highest security. Level A only has A1 class. A1 is similar to B3. A1has the obvious features a developer of system must adopt for a formal design specification to analyze a system. After analysis, the developer has to use verification technology to ensure that the system meets the design specifications. The entire installation operation must be done by the system administrator and each step has to provide formal documentation. In TCSEC, to identify the security and to give some assurance to the system, it has to meet the security requirements [14]. The TCSEC was replaced by CC. CC is a framework of mutually recognized evaluation criteria and it contains 3 parts: security model, security functional requirements and security assurance requirements. Security assurance components are the basis for the security assurance requirements and it expresses in Protection Profile (PP) or Security Target (ST) [15]. A Protection Profile is the security requirements of customers and a company of users for a class of Targets of Evaluation (TOE) [15]. A PP uses a template independently to express security requirement. This is useful when implementing a product line or a family of related products [7]. Protection Profile copy TCSEC security requirements of C2 and B1. Protection Profile include: a template of commercial security profile, Firewall profiles which use for packet filters and application gateways, Smart card profiles, Database profile and a role which is based on control profile [16]. A Security Target consists of a collection of security requirements and used to evaluate computer system or product [7]. Figure 1 The PP/ST specification framework [7] Evaluation is that use defined criteria to evaluate a computer system or IT product [16]. Figure 1 shows specification framework to the Targets of Evaluation. The Common Criteria evaluation process starts from identifying a TOE (Target of Evaluation), and then input an ST which describes the security functions of the TOE [16], the example of TOE is computer system or product, To see if the result of the system is secure, it should meet a set of security requirements or protection profile [7]. Common Criteria provides a set of Evaluation Assurance Levels (EAL) from EAL1 (lowest) to EAL7 (highest) and it will be awarded to products and system upon successful completion of evaluation (see Table 1). The Common Criteria is absorbed by ISO (NO. 15408) EAL1- Functionally tested. For the correct operation of EAL1, it requires a certain confidence of occasion. This situation is of the view that the security threats are not serious [7]. EAL1 provide the evidence of testing and its documentation. EAL2- Structurally tested. In the delivery of the design information and test results, EAL2 requires the developer collaboration. But do not spend too much energy beyond the good commercial operation of consistency. EAL3- Methodically tested checked. Without a lot of changes on the premise of reasonable development practices, it allows a conscientious developer to obtain maximum assurance during the design phase from the correct security engineering. EAL4- Methodically designed, tested, reviewed. It allows the developers to obtain maximum guarantee from the correct security engineering, the security engineering is based on good and strict commercial development practice. This development practice does not need much professional knowledge, skills or other resources. In the rational economic conditions, and to renovate an existing production line, EAL can achieve the highest level of result [7]. EAL5- Semi-formally designed and tested. It enables the developers to obtain maximum security from the security engineering. The security engineering is based on a strictly commercial development practice. It relies on the appropriate application of professional safety engineering technology for support. EAL6- Semi-formally verified design and tested. It enables the developers to gain a high level of certification through the application of safety engineering technology and strict development environment, and. This is to produce a costly TOE to protect high-value assets against major risks [16]. EAL7- Formally verified design and tested. It is applicable to safe TOE development and it applies to places where the risk is very high, or high value assets that worth higher expenses. In this session discussed TCSEC and CC, an explained evaluation class of TCSEC, evaluation assurance level of CC and the evaluation process. Those discussions are very important that helps to find out the similarities and difference of TCSEC and CC. Next session, TCSEC and CC will be compared and contrasted based on the above discussion. Compare and contrast TCSEC and CC This session will discuss the similarities and differences between the security standards based on the above description on TCSEC and CC. It will also state the strength of CC and to explain why CC is a relatively successful security evaluation standard. Similarities Even though TCSEC has been replaced by CC, they still have some similarities. Both of them are security evaluation standard and evaluate computer system by security level classification and each level has security requirements. Both of them provide confidentiality security functionality and evaluate Computer Operation System. Differences Although CC has some similarities as TCSEC, but both of them are different. TSCEC is only used in U.S. In the beginning, it was proposed that TCSEC was to focus on independent computer system and it suited evaluation of military operating system. TCSEC does not involve security criteria for open system and it is the criteria for static model. TSCEC just considered protecting system owner and operator but did not cover user security area especially for the security of telecommunication system user. And also only considered confidentiality for documents of system owner and it did not address integrity and availability. From Table 1 we see that the evaluation of TCSEC is mix security and functionality. So if any hardware of software is changed, it will start to evaluate the system again. But CC is recognized by ISO organization and it applies to nations. Compared CC with TCSEC, CC is more complete. Common Criteria is not only focus on operating system but also for Network and Database. Common Criteria involve security criteria for open system and the criteria for dynamic model. CC keeps system confidentiality, availability and integrity through TOEs security specifications. CC has distinguished security and functionality, any change does not affect the evaluation. The evaluation process of both also is different. TCSEC checks system to see if it is secure by using the security requirements which is classified by evaluation class. In a Common Criteria evaluation, use Common Criteria to evaluate the product or computer system. The evaluation stages are: Protection Profile evaluation, Security Targets evaluation, TOE evaluation and Assurance maintenance.CC evaluates system starting from identifying a TOE, and then developing a set of criteria to the TOE for evaluation. For each step, detailed information will be added. To get to know if the system is secure, it should meet a set of security criteria or protection profile. Finally TCSEC has been substituted by CC. That means TCSEC was abandoned but CC is still the ongoing security evaluation standard. The advantages of CC Form the above comparison of the differences between TCSEC and CC, we can point out that CC is a relatively successful security evaluation standard because CC has some advantages. CC is an international security standard and many countries acknowledge the testing result. CC is absorbed in security objectives and the related threats and the evaluation process help to enhance confidentiality, availability and integrity of the system. CC provides a set of security criteria in detail and the criteria details are easily understood by customer and supplier. Customer can use them to determine the security level of the products and also to find out their own security requirements. So that supplier can design product for them and also use them to identify their product or system security features. Customer can trust the evaluation because the testing is done independently and not by the supplier. In this session, the similarities and differences between TCSEC and CC have been discussed and after comparison, the advantages of CC have been indicated. Conclusion To sum up, through the discussion of the evaluation process and assurance level of TCSEC and CC, we found out the similarities and differences between the two standards and also the advantages of CC. TCSEC is firstly a security standard and it develops 4 levels and 7 evaluation classes. Each evaluation class contains security requirements and using the requirements it will help to identify the security level of the system or product. TCSEC has provided identification and authentication for user to access the system document and also to provide audit trial and access protection. TCSEC evaluates system or products by checking security requirements to see if the system meets them. TCSEC has been replaced by CC and CC is an international security evaluation standard. CC provides Protection Profiles and Security Targets which are documents for specifying security requirements. [2] CC has 7 Evaluation assurance levels. Because CC came from TCSEC, they have some similarities but actually they are quite different. TCSEC only applies to operation system and it focuses on the demand of confidentiality. CC has full description of security mode, security concepts and security functionality. Compared with TCSEC, CC has some advantages. The testing result is accepted by nations, supplier can design product for customer based on their requirements. CC keeps system confidentiality, availability and integrity. After comparison we can say that CC is relatively a successful security evaluation standard.
Friday, October 25, 2019
Frankenstein, the Novel :: essays research papers fc
How does information about early cognitive development relate to violence the creatures commits? à à à à à Human cognition is the study of how people think and understand. As part of growing up, there are four stages called the cognitive developmental stages that an individual goes through. From the sensory motor stage to the formal operational stage, human beings learn to interpret their surroundings of everyday life experiences. However, in the case of the Creature in the novel, Frankenstein, he was never developed in a cognitive way, and therefore, the creature was passively torn by opposing forces of human beings in his surrounding environments. Overall, cognitive development and the relation between the Creatureââ¬â¢s turn towards violence is a result of neglect, psychological indifferences, and lack of socialization skills. à à à à à There are a variety of perspectives and emphases within cognitive psychology of human beings. Psychological indifferences of the Creature creates conflicts within himself and his surroundings. If an individual has a different view of life, the resulting factor may be psychologically challenging. This Creature was brought to life with grotesque looks and an abnormal brain. He did not know any concepts to the environment surrounding him, and therefore, was a child in an adultââ¬â¢s body. According to Jean Piaget, when the Creature was first brought to life, he is in the ââ¬Ësensory motor stageââ¬â¢ of human development. This is the level at which ââ¬Å"individuals experience the world only through their sensesâ⬠(Macionis 65). Since the Creature was never taught right from wrong, he thought that whatever he was doing was the right concept. It is obvious that we do not commit acts of murder; however, in the Creatureââ¬â¢s world of his own, he though t an act of murder was entertainment and dramatizing when he first comes into contact with a little girl. For example, when the little girl comes and asks the Creature to play with her, he ends up throwing her into the lake, drowning her because she can not swim (Frankenstein). If this Creature was psychologically taught that he is larger than other humans and needs to be cautious with how he handles situations, such circumstances might be prevented. In a movie version titled, Mary Shelleyââ¬â¢s Frankenstein, the Creature and his creator, Victor Frankenstein are in a cave and they are both arguing with each other about the events that has happened with the murdering of Victorââ¬â¢s relatives. The Creature responds to Victorââ¬â¢s statements with, ââ¬Å"You gave me these emotions, but you did not tell me how to use themâ⬠(Mary Shelleyââ¬â¢s Frankenstein).
Wednesday, October 23, 2019
Regular Assignment
One of his duties is to serve as the coach for runners who hope to complete the New York City Marathon. He himself has won several marathons and ultra-marathons runner race. Thus he is more acquainted about the roles and responsibilities of coach for the marathon runners. After the introduction of David, case study drives us through understandings of how the complete training period of 16 weeks is carried out by athletes and runners. Initial 8 weeks he found it easy to train the runners.He was pleased looking the progress of the runners and had little difficulty in his role as coach. Some questions started to come in his mind regarding how to help his runners to achieve their goal. His issues of concern seemed quite different from those that he had expected to hear from other runners he previously trained for Marathons. Thus he divided runners and their concerns Into following three different groups. The first group comprised of all basic questions with newly joined runners who never had previous experiences.They kept on asking basic questions such as what to eat a day before marathon race, how much to drink and what kind of shoes to wear. The second group comprised of runners who had previously ran for marathons but were concerned about the effects of Davit's raining on their running, wanted to know the running mileage related to their possible marathon finish time. In addition their concern was to know whether consuming carbon-loading would improve their performances during the marathon.The third group comprised of seasoned runners who mostly finished marathon in top 10 of their respective divisions. These group too had some concerns related to feeling flat and acted a bit moody and down about training. The most important concern they carried was whether Davit's coaching would help them in other races besides the New York City Marathon. Hint David should use the following leadership strategy to train/coach his runners. The first group needs David to make sure that the runners will be motivated if they feel competent.Runners kept on asking questions such as what to eat a day before marathon race, how much to drink and what kind of shoes to wear. I think He needs to motivate the runners, make a diet plan and answer their questions they have. But he should also take a note that not to instruct all of the runners in a single group. Based on runners abilities he should have different training sessions. Because may be the beginners (group ) would keep asking basic questions like which shoes to wear, what to eat in a session which might not be interest to groups 3.For them it would lead to boredom sessions of training and might remove interest from attending further sessions and from Marathon race too. So he should take note of all runners and based on knowledge should keep training. He could have taken information session where all questions and issues are addressed. The second group was concerned about the effects of Davit's training on thei r running mileage related to their possible marathon finish time and forts reward they would get in return after the marathon race.Running a marathon is a huge deal and if people are nervous or unsure they will ask a ton of questions. I think he should explain them the benefits they would get with the training. In addition he as a coach needs to be there for them and coach them to the finish line. He should reduce everyone's stress when most seems nervous. Reassure the second group that they are doing great. The third group concern was not focused on current marathon race as objective by his training, but wanted to know if the payoff for their work valuable.David can motivate each of these groups by tending to the group's needs. Answer the beginners' group questions, make a diet plan. A final criticism that can be made of path- goal theory concerns a practical outcome of the theory. Path-goal theory suggests that it is important for leaders to provide coaching, guidance, and directi on for subordinates, to help subordinates define and clarify goals, and to help subordinates around obstacles as they attempt to reach their goals. In effect, this approach treats leadership as a one way event. The leader affects the subordinate.
Tuesday, October 22, 2019
Free Essays on Real Property Investment
Why do people use real property investment? Investment in property is most important investment instrument in Australia, as you know the richest 200 peopleà ¡Ã ¯s wealth is based on the real property. Although property must be viewed as an illiquid investment because the transfer costs of properties are high and the selling period averages several months, according to steady profit return and low risk, many people buy in property to against currency inflation, and to compensate increasing life expense contrasted to decreasing social security after retirement. How does it work? Negative gearing Gearing basically means borrowing to invest. An investment property that's negatively geared is purchased with a loan that has an annual net rental income amount that is less than the annual interest paid on the loan, plus the deductible expenses associated with maintaining the property. You get tax benefits by being negatively geared as you are able to deduct the costs of owning an investment property from your overall income. The biggest part of this deduction is the interest portion of your mortgage, but you can also claim such expenses as property management fees, loan costs and repairs. Because negative gearing deductions offset your income, they are most beneficial to high-income earners. What this means is the more you borrow, the more interest you pay and the bigger your deduction. While everyone wants a large tax deduction, you shouldn't over commit yourself in order to get one. You still have to make the mortgage payments and those lucrative tax benefits don't arrive until the end of the financial year. In periods of low inflation, the benefits of negative gearing are usually negligible. (Case study: Mr. Bill teaches accounting in TAFE. He is interested in a 2 bedrooms unit in Parramatta, which costs $360,000. His annual salary is $50,000. He gets $376,190 mortgage at 6.29% p.a. from Wizard home loan, calculate how much money ... Free Essays on Real Property Investment Free Essays on Real Property Investment Why do people use real property investment? Investment in property is most important investment instrument in Australia, as you know the richest 200 peopleà ¡Ã ¯s wealth is based on the real property. Although property must be viewed as an illiquid investment because the transfer costs of properties are high and the selling period averages several months, according to steady profit return and low risk, many people buy in property to against currency inflation, and to compensate increasing life expense contrasted to decreasing social security after retirement. How does it work? Negative gearing Gearing basically means borrowing to invest. An investment property that's negatively geared is purchased with a loan that has an annual net rental income amount that is less than the annual interest paid on the loan, plus the deductible expenses associated with maintaining the property. You get tax benefits by being negatively geared as you are able to deduct the costs of owning an investment property from your overall income. The biggest part of this deduction is the interest portion of your mortgage, but you can also claim such expenses as property management fees, loan costs and repairs. Because negative gearing deductions offset your income, they are most beneficial to high-income earners. What this means is the more you borrow, the more interest you pay and the bigger your deduction. While everyone wants a large tax deduction, you shouldn't over commit yourself in order to get one. You still have to make the mortgage payments and those lucrative tax benefits don't arrive until the end of the financial year. In periods of low inflation, the benefits of negative gearing are usually negligible. (Case study: Mr. Bill teaches accounting in TAFE. He is interested in a 2 bedrooms unit in Parramatta, which costs $360,000. His annual salary is $50,000. He gets $376,190 mortgage at 6.29% p.a. from Wizard home loan, calculate how much money ...
Monday, October 21, 2019
Harry Pace and Black Swan Records
Harry Pace and Black Swan Records Overview In 1921, entrepreneur Harry Herbert Pace established Pace Phonograph Corporation and the record label, Black Swan Records. As the first African-American owned record company, Black Swan was known for its ability to produce ââ¬Å"race records.â⬠And the company proudly stamped its slogan on every album cover ââ¬Å"The Only Genuine Colored RecordsOthers are Only Passing for Colored.â⬠Recording the likes of Ethel Waters, James P. Johnson, as well as Gus and Bud Aikens.à Achievements Published the first African-American illustrated journal, The Moon Illustrated Weekly. Established the first African-American owned record company, Pace Phonograph Corporation and sold recordings as Black Swan Records. Fast Facts Born: January 6, 1884 in Covington, Ga. Parents: Charles and Nancy Francis Pace Spouse: Ethelyne Bibb Death: July 19, 1943 in Chicago Harry Pace and the Birth of Black Swan Recordsà After graduating from Atlanta University, Pace moved to Memphis where he worked a variety of jobs in banking and insurance. By 1903, Pace à launched a printing business with his mentor, W.E.B. Du Bois. Within two years, the duo collaborated to publish the magazine The Moon Illustrated Weekly. Although the publication was short-lived, it allowed Pace a taste of entrepreneurship.à In 1912, Pace met musician W.C. Handy. The pair began writing songs together, relocated to New York City, and established the Pace and Handy Music Company. Pace and Handy published sheet music that was sold to white-owned record companies. Yet as the Harlem Renaissance picked up steam, Pace was inspired to expand his business. After ending his partnership with Handy, Pace establish the Pace Phonograph Corporation and the Black Swan Record Label in 1921. The company was named for performer Elizabeth Taylor Greenfield who was called ââ¬Å"The Black Swan.â⬠Famed composer William Grant Still was hired as the companyââ¬â¢s musical director. Fletcher Henderson became Pace Phonographââ¬â¢s bandleader and recording manager. Working out of the basement of Paceââ¬â¢s home, Black Swan Records played an important role making jazz and blues mainstream musical genres. Recording and marketing music specifically to African-American consumers, Black Swan recorded the likes of Mamie Smith, Ethel Waters and many others. In its first year of business, the company made an estimated $100,000. The following year, Pace purchased a building to house the business, hired regional district managers in cities throughout the United States and an estimated 1,000 salespeople. Soon after, Pace joined forces with white business owner John Fletcher to buy a pressing plant and recording studio. Yet Paceââ¬â¢s expansion was also the beginning of his downfall. As other record companies realized that African-American consumerism was powerful, they also began hiring African-American musicians.à By 1923, Pace had to close the doors of Black Swan. After losing to major recording companies that could record for lower prices and the arrival of radio broadcasting, Black Swan went from selling 7000 records to 3000 daily. Pace filed for bankruptcy, sold his pressing plant in Chicago and finally, he sold Black Swan à to Paramount Records.à Life After Black Swan Recordsà Although Pace was disappointed by the quick rise and fall of Black Swan Records, he was not deterred from being a businessman. Pace opened the Northeastern Life Insurance Company. Paceââ¬â¢s company went on to become one of the most prominent African-American owned businesses in the northern United States. Before his death in 1943, Pace graduated from law school and practiced as an attorney for several years.
Sunday, October 20, 2019
A consideration of the principles and practice that underpin the Early Years Foundation Stage and how the current framework relates to young childrens needs and interests The WritePass Journal
A consideration of the principles and practice that underpin the Early Years Foundation Stage and how the current framework relates to young childrens needs and interests Introduction A consideration of the principles and practice that underpin the Early Years Foundation Stage and how the current framework relates to young childrens needs and interests ) infers that such an approach could have positive longitudinal consequences for the child, including improved academic attainment and retention of knowledge, which seems to be a sound rationale for such an approach. Whilst it seems essential that the indoor environment should be stimulating cognitively, it may be wise not to neglect the emotional aspect of it.à Again, the key worker is at the centre of providing the warmth needed in an enabling environment. Nutbrown and Page (2008) assert that they should show warm responses to the children under their care and react well to them. In essence, an enabling environment is made up of the components of suitable and stimulating indoor and outdoor areas, which the key worker is central in maintaining and facilitating. Principle 4- Children develop and learn in different ways and rates The final principle espoused by the EYFS framework is perhaps more concerned with the cognition of children, although it does refer to their social and emotional development in part. Nevertheless, Katz (1988, as cited in Carr, 2001, p.21) hypothesises that each child has a certain ââ¬Ëdispositionââ¬â¢, something which is distinct from learning; it is concerned more with how they react to certain situations and the habits they adopt and carry out on a regular basis. In a later document, Katz (1993) elaborates that dispositions in young children are normally learned from those around or the environment they are raised in or looked after, which seems to resonate with Banduraââ¬â¢s (1977) theory of modelling mentioned earlier in the assignment. Katz (1993) also articulates that dispositions are strengthened when they are acknowledged and efforts are made to continue them (particularly if they are good habits), which seems to emphasise the importance of treating the child as an i ndividual. It seems evident that all children learn and develop in different ways, as evidenced by the argument above. However, a conjecture could be made that there may be certain strategies which a practitioner or worker can implement which will result in children developing into sensible and mature adults. One way in which to do this is to cultivate a childââ¬â¢s resilience in their ability to complete a task or try a new activity.à Children may give up if they perceive the task to be beyond their capabilities and not extend themselves to complete this. This could be a natural response from the child (particularly if the task is incommensurate with their skillset) or it could be something that they have learned over time. Dweck (1975: 673) terms this as ââ¬Ëlearned helplessnessââ¬â¢, where a child habitually gives up in the face of a challenging task or adversity, possibly because of a lack of response from the adult in encouraging the child to complete the task and persevere. Combining the sentiments expressed by Katz and the argument above, could be essential in helping children to progress appropriately, particularly when faced with unfamiliar situations and tasks.à Siraj- Blatchford et al. (2002) concluded in their Researching Effective Pedagogy in the Early Years (REPEY) study that shared sustained thinking was crucial in helping a child to tackle new problems and persist. This is defined as two or more individuals (with at least one adult ââ¬Ëfacilitatorââ¬â¢) working together to complete a task, although the authors stress that each person should be actively contributing to the task, and that there must be a progression towards an eventual solution, even if that is reached straight away. This coincides with Vygotskyââ¬â¢s (1977) theory of cognitive development, which posits that a child will enhance their zone of proximal development (the difference between what they can do on their own and with help) if they are supported by a more know ledgeable other such as an adult or more capable peer.à Both arguments suggest that collaboration between adults and children is essential to further the childââ¬â¢s development, although again the manner in which this is done should be unique to the child by using questioning which is appropriate to the childââ¬â¢s level of cognitive development (Bloom et al., 1956). Conclusion The rationale which underpins the EYFS framework is the need to treat the child as a unique individual and consider their needs at length, in a cognitive, emotional, social and physical sense to facilitate optimum development in them. There are several ways to ensure this, including that the environment is stimulating and appropriate enough for the childââ¬â¢s needs, that they have access to a multitude of activities, that the key worker has a warm and fulfilling relationship with the child and that they encouraged to develop a growth mind set and persevere with challenging tasks with the facilitation of another adult. Arguably, if a childcare provider follows all of the actions above and adheres to the EYFS framework, then this should allow for children to progress to the desired level of development and maturity. References Bandura, A. (1977) Social Learning Theory. Englewood Cliffs, NJ: Prentice Hall. Bloom, B. S., Engelhart, M. D., Furst, E. J., Hill, W. H. and Krathwohl, D. R. (1956) Taxonomy of educational objectives: The classification of educational goals. Handbook I: Cognitive domain. New York: David McKay Company. Bowlby, J. (1951) ââ¬ËMaternal Care and Mental Health.ââ¬â¢ World Health Organization Monograph. Bowlby, J. (1953) Child Care and the Growth of Love. London: Penguin Books. Bruner, J. S. (1961) ââ¬ËThe act of discoveryââ¬â¢. Harvard Educational Review, 31 (1): 21ââ¬â32. Carr, M. (2001) Assessment in Early Childhood Settings. London: SAGE. Department for Family, Education and Skills (2004) Every Child Matters. [Online]. Available at: http://webarchive.nationalarchives.gov.uk/20130401151715/https://www.education.gov.uk/publications/standard/publicationdetail/page1/dfes/1081/2004 (Accessed: 24 November 2014). Department for Education (2010) Social and emotional aspects of learning (SEAL) programme in secondary schools: national evaluation. [Online]. Available at: https://www.gov.uk/government/publications/social-and-emotional-aspects-of-learning-seal-programme-in-secondary-schools-national-evaluation (Accessed: 24 November 2014). Department for Education (2013a) Improving the quality and range of education and childcare from birth to 5 years. [Online]. Available at: https://www.gov.uk/government/policies/improving-the-quality-and-range-of-education-and-childcare-from-birth-to-5-years/supporting-pages/early-years-foundation-stage (Accessed: 24 November 2014). Department for Education (2013b) Early years outcomes: A non-statutory guide for practitioners and inspectors to help inform understanding of child development through the early years. [Online]. Available at: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/237249/Early_Years_Outcomes.pdf (Accessed: 24 November 2014). Department for Education (2014) Early years foundation stage framework. [Online]. Available at: https://www.gov.uk/government/publications/early-years-foundation-stage-framework2 (Accessed: 24 November 2014). Dweck, C.S. (1975) ââ¬ËThe role of expectations and attributions in the alleviation of learned helplessness.ââ¬â¢ Journal of Personality and Social Psychology, 31: 674-685. Dweck, C. (2006)à Mindset: The New Psychology of Success. New York: Ballantine Books. Elfer, P., Goldschmied, E. and Selleck, D. (2003) Key Persons in the Nursery: Building relationships for quality provision. London: David Fulton. Garrick, R., Bath, C., Dunn, K., Maconochie, H., Willis, B. and Claire Wolstenholme (2010) Childrenââ¬â¢s experiences of the Early Years Foundation Stage. DfE: London. Gardner, H. (2004) Changing Minds: The art and science of changing our own and other peoples minds. Harvard Business School Press. Gov. UK (2014) Free early education and childcare. [Online]. Available at: https://www.gov.uk/free-early-education (Accessed: 24 November 2014). Katz, L.G. (1988) ââ¬ËWhat Should Young Children Be Doing?ââ¬â¢ American Educator: The Professional Journal of the American Federation of Teachers: 29-45. Katz, L. (1993) Dispositions: Definitions and implications for early childhood practices. ERIC Clearinghouse on Elementary and Early Childhood Education. Nutbrown, C. and Page, J. (2008) Working with Babies and Children Under Three. London: Sage. Piaget, J. (1952) The Origin of Intelligence in Children. New York: International University Press, Inc. Siraj-Blatchford, I., Sylva, K., Muttock, S., Gilden, R. and Bell, D. (2002) Researching Effective Pedagogy in the Early Years (REPEY) DfES Research Report 365. HMSO London: Queenââ¬â¢s Printer. Steel, N. (2012) Encyclopaedia of the Sciences of Learning. New York: Springer. Sylva, K., Melhuish, E., Sammons, P., Siraj-Blatchford I. and Taggart, B. (2004) The Effective Provision of Pre-School Education (EPPE) Project: Final report. London: DfES and Institute of Education, University of London. Vygotsky, L. S. (1978) Mind in society: The development of higher psychological processes. Cambridge, MA: Harvard University Press
Saturday, October 19, 2019
GFP Green fluorescent protein Essay Example | Topics and Well Written Essays - 500 words
GFP Green fluorescent protein - Essay Example Microorganisms can be easily used for genetic tailoring by means of genetic tools to study the modifications in environmental conditions. Reporter genes are tagged with multicoloured fluorescent proteins which aid in identifying the chemical effects prevailing in the environment. The engineered microorganisms are then used for whole cell array set-up on silicon chips and diverse optic fibres to get bioavailability of pollutants which could be correlated with their impact on life (Belkin, 2003). Reporter gene is expressed when it is fused with a promoter target sequences. Thus expression can be observed by the appearance of the reporter gene, in view of the fact that reporter is tagged with the active gene of interest. The promoter is tagged with a marker gene such as GFP, a stable molecule used to identify the phenotype or the genotype of the transformed organism. Luminescence markers: emit light making the selection process easy and simple moreover, they measure the cellular activity swiftly. FACS (fluorescence activated cell sorting) is performed with GFP, YFP and BFP i.e. green, yellow and blue fluorescent proteins respectively. The molecules do not require oxygen for fluorescence (Belkin, 2003). In transgenic organisms GFP molecule is integrated with active gene, expression of gene is observed through green glow under UV radiation. Transgenic organisms of various species such as E coli, C elegans, Drosophila were made to glow by inserting GFP reporter gene. Toxicity of GFP is not observed in both prokaryotic and eukaryotic organism, indicating the safety of the molecule. Small size of GFP makes it ideal for reporter gene or if GFP is tagged at the end of the active gene, it is expressed with the gene once the gene undergoes the process of transcription and translation, however, expression of GFP does not affect the protein; conversely, the protein can be seen as green fluorescence indicating the
Friday, October 18, 2019
Current State of Mobile Crowd Sensing Essay Example | Topics and Well Written Essays - 2000 words
Current State of Mobile Crowd Sensing - Essay Example The devices consist of certain sensing equipment and wireless power that make it easier to develop and upload data to the internet (Ganti et al. Page 32). The mobile devices are equipped with various communication computing and sensing systems. They boost the functions of the daily life objects or involved in the collection of information from the environment by themselves. These devices have got applications in all sectors of the economy including health sector, industrial sector, agricultural sector and education sectors. Information sharing and updating have become easier and the information have been of high quality. The paper therefore discusses in broad the current state of art of mobile Crowdsensing looking into the current application in technology. It also discusses the possible future advances and challenges facing this technology. The mobile crowdsensing applications fall into two broad categories considering the type of facts that are analyzed; personal and computing sensing. The application of personal sensing is directed towards the individual. A good example is examining the movement of individuals, especially during exercise to determine his or her health status. Another example is the one that examines the method of transportation of an individual in order to get the carbon footprint of the person. Community sensing involves examination of facts that cannot be carried out by one person. A good example is the examination of the level of air pollution or traffic congestion. It has therefore been made easier to carry out self or community assessment. One can easily identify and know the body status and decide on whether to seek medical assistance at certain times (Ganti et al.Page 32). The current state of the art of mobile crowdsensing has shown its applications in various sectors in the world. Its application has been seen in the environment, infrastructure and social applications. The environmental applications involve the natural environment including examining pollution levels, wildlife habitats and levels of water. These applications involve looking the facts in the environment at a large and involved the main person.Ã Ã
Some Aspect of Early Victorian Period in John Stuart Mill's The Essay
Some Aspect of Early Victorian Period in John Stuart Mill's The Subjection of Women - Essay Example Mrs. Mallard, the main character of the story is told that her husband has died in a train crash. With this information she sits throughout the story and moves forward in her life at least in her mind. The reader is told that Mrs. Mallard has a heart condition in the beginning of the story. Mrs. Mallard describes her plight with her husband. She cannot talk about anything she wants to talk about, she gets ignored and she has to mind her place. Mrs. Mallard resolves herself that she is finally free and she goes through a shift in her consciousness and decides what she will do next. Unfortunately at the end of the story she finds that her husband did not die in the train crash and her only way out now is to have a heart attack and die; which she does at the end. The short story does show how she was expected to listen to him and do what he said which supports what Mill says. An interesting point is that women today are not much different from women then although they have worked hard towards getting a voice. Kuhl describes spinsterhood during this time and the fact that women were to have "high moral standards" and that they were to adhere to "strict rules of conduct in marriage and courtship." Specifically she states: Based on high moral standards, strict rules of conduct in marriage and courtship, and a public lifestyle that would reflect pious dignity, women of the Middle Class were carefully conditioned and expected to live up to a specific code of behavior. The ultimate goal of which was marriage. It became the duty of every woman of the Middle Class to marry and produce children, preferably boys to inherit the newfound status and wealth of the class (par. 3). This statement creates an image of slavery for women of this time period because they were more breeding stock than part of a marriage. They were expected to do only what the man said and which is
Romantic Literature Essay Example | Topics and Well Written Essays - 2000 words
Romantic Literature - Essay Example The evolution of the style of romantic literature was borne out of the need of many writers to express their inner thoughts in a way that is characterized by freedom, imagination, as well as creativity, without the impediment of following normal human logic. As a result, many romantic works such as Samuel Taylor Coleridgeââ¬â¢s The Rime of the Ancient Mariner and Horace Walpoleââ¬â¢s The Castle of Otranto bear situations that are not realistic, even during the time that these works were published. While these two works are entirely different, one is a poem while the other is a novel, what ties these two together is the creation of suspense as far as the main characters of the stories or narratives are concerned. The succession of events may not be as clear as logic to predict, thus adding a sense of uncertainty to what could possibly happen to the protagonists, the antagonists, or both. In the course of this analysis, these two important works from the Romanticist era of litera ture would be used to illustrate how the combination of the use of imaginary settings as well as adding a feeling of uncertainty in behalf of the characters not only appeal to the senses of the readers but also draw them into their lives and shoes, as well as being able to see the triumphs, the losses, and other emotions of the cast as real emotions that are valid in their given situations. Real Emotions in Surreal Situations In comparing the first chapter of The Castle of Otranto to the summary of the poem The Rime of the Ancient Mariner, it can be seen that the settings of the narratives are surreal or even imaginary. However, the characters are portrayed as ordinary people, without any superpowers or whatnot. This puts real people in unreal or surreal situations. In the case of the Ancient Mariner and the rest of the crew of the ship, they felt real terror when they saw the ghost ship with Death and Night-mare Life-in-Death: Are those her ribs through which the Sun Did peer, as t hrough a grate? And is that Woman all her crew Is that a Death? And are there two? Is Death that womanââ¬â¢s mate? (Coleridge 11). The writer vividly described the people or apparitions aboard the appearing ship in order to help the reader visualize the passengers of the ghost ship. A few lines after the description of the passengers of the ghost ship came the terror that the mariner and his shipmates felt after Death and Night-mare Life-in-Death decided which souls they would take as their own, We listened and looked sideways up! Fear at my heart, as at a cup My life-blood seemed to sip! (Coleridge 11). To put it bluntly, the mariner felt as if his blood has totally drained away after hearing that the souls of all passengers of their marooned ship would be taken away. It can be likened to how a person would feel when facing immediate danger or seeing it approach, where time seems to stand still and it would feel like there is no other choice but to die. The same feeling of terro r is also depicted in the character Isabella when she was being pursued by Prince Manfred in the first chapter of The Castle of Otranto: ââ¬Å"Words cannot paint the horror of the Princessââ¬â¢
Thursday, October 17, 2019
Incorporate Comorbidity Problem Essay Example | Topics and Well Written Essays - 1500 words
Incorporate Comorbidity Problem - Essay Example Neurons, which are brain cells, are responsive to distinctive types of neurotransmitters having receptors built purposely for them (Porth & Matfin, 2009). Those neurons that tend to be sensitive to certain neurotransmitters cluster together, thereby forming circuits in the brain, responsible for processing certain types of information. Neurotransmitters are discharged from a neuron at the time it signals another brain cell; these neurotransmitters are discharged to the small space amid the two neurons known as the synapse (Porth & Matfin, 2009). Inside the synapse, the neurotransmitters tend to attach to the receptors at the ending of another neuron, thereby affecting the action of the new neuron. Consequently, the new neuron absorbs as much of the neurotransmitter as it possibly can and then discharges the excess back to the synapse. After that, the first neuron goes ahead to reabsorb the excess; this process through a process is referred to as reuptake (Porth & Matfin, 2009). In th e brain, there are various neurotransmitters, two of which are involved in schizophrenia symptoms, that is dopamine and glutamate (Craft, Gordon, & Tiziani, 2011). Dopamine happens to be primarily responsible for movement and thoughts, while, at the same time being related with novelty seeking, or concern in new experiences, as well as reward. Apparently, illegal drugs such as cannabis, cocaine and methamphetamine act by affecting the function of dopamine in the brain; therefore, dopamine is related with feelings of not only pleasure but also well-being (Craft et al., 2011). Dopamine paths within the brain tend to be extremely specialized, thereby being capable of influencing different types of behavior or thinking. Thus, people with high intensities of dopamine in parts of the brain might also suffer from psychotic symptoms or even paranoid thinking that are symptoms of schizophrenia (Craft et al., 2011). Glutamate happens to be other neurotransmitter, which might play a significan t role in schizophrenia. Glutamate plays a key part in learning, formation as well as encoding of memory (Craft et al., 2011). There are hallucinogenic drugs such as PCP used in blocking glutamate receptors; however, amphetamines, PCP are capable of causing paranoia, which apes schizophrenic symptoms. In instances where people suffer from schizophrenia and use PCP, it worsens their symptoms (Craft et al., 2011). Research shows that an interaction between dopamine and glutamate happens to be the center of schizophrenia; nonetheless, dopamine receptors are capable of reducing glutamate action; in case there are unusually many dopamine receptors, the effects of glutamate will be blocked. Question Two Reports by the American Psychological Association (2001)
Haemathology-oncology practice Assignment Example | Topics and Well Written Essays - 2000 words
Haemathology-oncology practice - Assignment Example Based on the reports of that test, Ruth was informed that she has acute lymphatic leukemia (ALL) and will need to commence chemotherapy with Cyclophosphomide, Cytarabine and Mercaptoprine for which Hickman line was inserted and kept in situ. She received 4 cycles of chemotherapy until this admission when she got admitted for a complication, febrile neutropenia On this admission, the sixth one since her diagnosis, Ruth presented with fever. On examination, she was febrile, feeling unwell, tearful and anxious, and feeling hot and cold. Her temperature was 38.4C and heart rate 115 beats per minute. Neutrophil count was 0.3 percent, which is suggestive of severe neutropenia. Septic screen was done which included urine culture and sensitivity, stools culture and sensitivity, sputum examination and a full blood count. Chest x-ray and throat swab also was done. Intravenous fluids were commenced as per her weight and first line broad spectrum antibiotics as per hospital protocols were prescr ibed. Problem-1: Chemotherapy-related neutropenia Overview of the problem Ruth is diagnosed with febrile neutropenia.... Neutrophils are very important for innate immunity and comprise the first cellular component of any inflammatory response (Friese, 2006). Neutropenia is common adverse effect of cytotoxic chemotherapy (Brien et al, 2006). This condition typically occurs in the presence of other side effects and these concurrent events affect the quality of life of the patient. Other side effects include asthenia, anorexia, vomiting and dehydration. In addition to these events various precautions that are taken to minimise neutropenia also affect the quality of life. The degree of febrile neutropenia also influences the intensity of adverse events (Padilla and Ropka, 2005). The duration of chemotherapy induced neutropenia is typically 7-10 days (Friese, 2006). The blood culture of Ruth grew staphylococcus aureus. Urine and other cultures were negative. The staphyloccus aureus was resistant to vancomycin. Hence her antibiotics were changed to meropenem and gentamycin. Ruth was constantly monitored for improvement both through physical examination and laboratory tests. This is because, neutropenia is associated with significant morbidity and mortality because of the increased risk of developing infections that could be life threatening. The risk of infections correlates with drop 0f absolute neutrophil count and those with severe neutropenia (ANC < 0.5 ? 109/L) are at greatest risk of developing infections which are life threatening. In Ruth, the neutropenic count was 0.3 and she presented with only fever. More often than not, infection due to neutropenia manifests as just fever and hence presence of fever in neutropenic patients warrants close monitoring (Padilla and Ropka, 2005).
Wednesday, October 16, 2019
Romantic Literature Essay Example | Topics and Well Written Essays - 2000 words
Romantic Literature - Essay Example The evolution of the style of romantic literature was borne out of the need of many writers to express their inner thoughts in a way that is characterized by freedom, imagination, as well as creativity, without the impediment of following normal human logic. As a result, many romantic works such as Samuel Taylor Coleridgeââ¬â¢s The Rime of the Ancient Mariner and Horace Walpoleââ¬â¢s The Castle of Otranto bear situations that are not realistic, even during the time that these works were published. While these two works are entirely different, one is a poem while the other is a novel, what ties these two together is the creation of suspense as far as the main characters of the stories or narratives are concerned. The succession of events may not be as clear as logic to predict, thus adding a sense of uncertainty to what could possibly happen to the protagonists, the antagonists, or both. In the course of this analysis, these two important works from the Romanticist era of litera ture would be used to illustrate how the combination of the use of imaginary settings as well as adding a feeling of uncertainty in behalf of the characters not only appeal to the senses of the readers but also draw them into their lives and shoes, as well as being able to see the triumphs, the losses, and other emotions of the cast as real emotions that are valid in their given situations. Real Emotions in Surreal Situations In comparing the first chapter of The Castle of Otranto to the summary of the poem The Rime of the Ancient Mariner, it can be seen that the settings of the narratives are surreal or even imaginary. However, the characters are portrayed as ordinary people, without any superpowers or whatnot. This puts real people in unreal or surreal situations. In the case of the Ancient Mariner and the rest of the crew of the ship, they felt real terror when they saw the ghost ship with Death and Night-mare Life-in-Death: Are those her ribs through which the Sun Did peer, as t hrough a grate? And is that Woman all her crew Is that a Death? And are there two? Is Death that womanââ¬â¢s mate? (Coleridge 11). The writer vividly described the people or apparitions aboard the appearing ship in order to help the reader visualize the passengers of the ghost ship. A few lines after the description of the passengers of the ghost ship came the terror that the mariner and his shipmates felt after Death and Night-mare Life-in-Death decided which souls they would take as their own, We listened and looked sideways up! Fear at my heart, as at a cup My life-blood seemed to sip! (Coleridge 11). To put it bluntly, the mariner felt as if his blood has totally drained away after hearing that the souls of all passengers of their marooned ship would be taken away. It can be likened to how a person would feel when facing immediate danger or seeing it approach, where time seems to stand still and it would feel like there is no other choice but to die. The same feeling of terro r is also depicted in the character Isabella when she was being pursued by Prince Manfred in the first chapter of The Castle of Otranto: ââ¬Å"Words cannot paint the horror of the Princessââ¬â¢
Tuesday, October 15, 2019
Haemathology-oncology practice Assignment Example | Topics and Well Written Essays - 2000 words
Haemathology-oncology practice - Assignment Example Based on the reports of that test, Ruth was informed that she has acute lymphatic leukemia (ALL) and will need to commence chemotherapy with Cyclophosphomide, Cytarabine and Mercaptoprine for which Hickman line was inserted and kept in situ. She received 4 cycles of chemotherapy until this admission when she got admitted for a complication, febrile neutropenia On this admission, the sixth one since her diagnosis, Ruth presented with fever. On examination, she was febrile, feeling unwell, tearful and anxious, and feeling hot and cold. Her temperature was 38.4C and heart rate 115 beats per minute. Neutrophil count was 0.3 percent, which is suggestive of severe neutropenia. Septic screen was done which included urine culture and sensitivity, stools culture and sensitivity, sputum examination and a full blood count. Chest x-ray and throat swab also was done. Intravenous fluids were commenced as per her weight and first line broad spectrum antibiotics as per hospital protocols were prescr ibed. Problem-1: Chemotherapy-related neutropenia Overview of the problem Ruth is diagnosed with febrile neutropenia.... Neutrophils are very important for innate immunity and comprise the first cellular component of any inflammatory response (Friese, 2006). Neutropenia is common adverse effect of cytotoxic chemotherapy (Brien et al, 2006). This condition typically occurs in the presence of other side effects and these concurrent events affect the quality of life of the patient. Other side effects include asthenia, anorexia, vomiting and dehydration. In addition to these events various precautions that are taken to minimise neutropenia also affect the quality of life. The degree of febrile neutropenia also influences the intensity of adverse events (Padilla and Ropka, 2005). The duration of chemotherapy induced neutropenia is typically 7-10 days (Friese, 2006). The blood culture of Ruth grew staphylococcus aureus. Urine and other cultures were negative. The staphyloccus aureus was resistant to vancomycin. Hence her antibiotics were changed to meropenem and gentamycin. Ruth was constantly monitored for improvement both through physical examination and laboratory tests. This is because, neutropenia is associated with significant morbidity and mortality because of the increased risk of developing infections that could be life threatening. The risk of infections correlates with drop 0f absolute neutrophil count and those with severe neutropenia (ANC < 0.5 ? 109/L) are at greatest risk of developing infections which are life threatening. In Ruth, the neutropenic count was 0.3 and she presented with only fever. More often than not, infection due to neutropenia manifests as just fever and hence presence of fever in neutropenic patients warrants close monitoring (Padilla and Ropka, 2005).
Traditional learning styles adaptation Essay Example for Free
Traditional learning styles adaptation Essay In the last decade, many universities have started to adapt traditional learning styles to new technologies. They have done so because flexible learning allows the student to study at their own time and pace, which fits in with their lifestyle with the aid of technology. Technology has allowed the delivery of lectures to become more varied and imaginative and therefore more accessible to a wider student base. They have also done so because flexible learning allows students to access university courses without having to step foot within a lecture hall therefore it has become more widely available to students as it fits in with their lives and can be worked around their schedules, whether they are in the outback, different country, working etc. Technology has allowed the lectures to be accessible anywhere anytime as long as you have access to internet. Task 2 1.Reference Lodge, J 2010. ââ¬ËCommunicating with first year students, so many channels but is anyone listening?ââ¬â¢ A practice reportââ¬â¢. The international Journal of the First Year in Higher Education, vol. 1, no. 1, pp. 100-105. 2.Purpose and argument Communication with students is constantly changing with new technology, whilst many enjoy communicating through social networking and other online media sites, many also prefer a more traditional method of communication. Technology will continue to develop and getting important information over to students without it becoming lost within social networking sites will continue to become difficult. Therefore there needs to be options for getting messages across to students from all age groups. 3.Academic credibility Jason lodge is a psychological scientist and a well-known lecturer at Griffith University. He is also a researcher at the University of Queensland as well as other well-known Universities in Australia. His paper ââ¬ËCommunicating with first year students: so many channels but is anyone listening: a practice reportââ¬â¢ was published in 2010 making it fairly recent and not out dated. Most of his referencing is also fairly recent within the last ten years making it more academically credible. The other 12 end text references that Lodge uses are also based on factual information and published in journals and well known publishers such as Emerald Group Publishing Limited. 4.Headings and their main ideas Abstract In todayââ¬â¢s modern world, universities have to keep up with the quick changing world of technology in order to communicate students. As technology changes frequently, it is difficult to find out what the students prefer for these communications. Social networking and other new online deliveries were generally met with a positive feedback from students. Background New technologies Higher education has radically changed with the modernisation of new information. Adopting new technology too eagerly has led to a situation where communication between and organisations and students are being lost. It is difficult to find which hi-tech channel is efficient and successful in getting messages across to students without getting lost and what is best for studying. The issues surrounding communication with first year students Various groups of students are entering higher education which presents complications in making sure communication needs of all students are met. The younger generations seems to be thriving on modern technology whilst the older generation prefers the more established lines of communications. However what is better for some students may not necessarily be good for others therefore finding something that works for everyone is fairly difficult. The current research Introduction Understanding studentsââ¬â¢ needs and preferences for communication channels within university life needs to be closely monitored and met. This needs to take into consideration, the wide age range within the first year of University life. Which communication method also needs to be observed as the more popular means of communication? Methods Social networking sites seem to be the most popular form of communications. With this in mind a group of students in their first year of studying were asked to complete a survey about which communication methods they preferred to receive messages from regarding administrative and educational issues. Results and discussions The result of this research showed that social networking sites were amongst the highest preferred methods of communications amongst university students for unofficial teamwork between students. However concerns were raised about the privacy of social networking sites when it came to communications with the university. On the other hand, when it came to communication about administrative or academic issues, students preferred to have contact either via email, in person or by phone. Recommendations The recommendations were that official messages from the Universities were best left to more recognized methods of communications but that the universities could use the social media outlets for more informal communications as long as they kept the messages short and to the point. The recommendation also suggested that it didnââ¬â¢t really matter what the generation gap was amongst the first year students as they were all catching up with the know-how of modern technology. Outcomes of discussion and reflections The problems of communicating necessary information to students seem to be across the board throughout other learning institutions. Students are continually inundated with information from the establishments therefore institutions need to make it simply for students to use and access, they need to present it in such a way that it is interesting, eye catching and encourages the student to participate with the organization as well as making it cost effective for the establishment. It was also established that social networking sites are probably best left for the students to communicate informally amongst one another rather than universities trying to communicate with students through these mean as their messages were largely overlooked and went unnoticed. As technology continues to grow and more forward, this will always present a communication problem for universities with first year students as they themselves are often also trying to not only cope with life as a first year student but also with the many new technical forms of communication that are constantly flooding the market. 5.Relevance or usefulness This reading will be very useful in doing my assignment because Lodge covers all aspects of flexible learning. He has looked at the problems that modern technology brings and how the different generations within the first year of learning will cope with it. How the delivery of the materials will be received from first year students and the problems that first year students face in accessing the materials as technology continues to grow and improve. Lodge has also tried to establish in what way is the best method for establishments to get their communications across to students.
Monday, October 14, 2019
Importance Of Time In Distributed Systems
Importance Of Time In Distributed Systems Time is an important and interesting issue in Distributed Systems for several reasons. First, time is a quantity we always want to measure accurately. In order to know at what time of day a particular event occurred at a particular computer, it is necessary to synchronize its clock with an authoritative, external source of time. Second, algorithms that depend upon clock synchronization have been developed for several problems in distribution; these include maintaining the consistency of distributed data, checking the authenticity of a request sent to a server and eliminating the processing of duplicate updates [1] In Centralized systems, there is no need for clock synchronization because, generally, there is only a single clock. A process gets the time by simply issuing a system call to the kernel. When another process after that tries to get the time, it will get a higher time value. Thus, in such systems, there is a clear ordering of events and there is no ambiguity about the times at which these events occur. [4] In Distributed systems, there is no global clock or common memory. Each processor has its own internal clock and its own notion of time. In practice, these clocks can easily drift apart by several seconds per day, accumulating significant errors over time. Also, because different clocks tick at different rates, they may not remain always synchronized although they might be synchronized when they start. This clearly poses serious problems to applications that depend on a synchronized notion of time. Distributed systems are subject to timing uncertainties as certain processes may lack a common notion of real time. Due to an uncertainty in message delay time, absolute process synchronization is known to be impossible for such systems The literature presents issues of timing in distributed systems, physical clocks and their synchronization problems, algorithms for synchronizing physical clocks are presented with their limitations, and also techniques for implementing logical clocks which are used to monitor the order of events without measuring the physical time at which the events occurred The concept of time Let us begin by asking this simple question; does anybody really know what time it is [3] As Lamport notes, the concept of time is fundamental to our way of thinking [7] In fact, real time helps to master many problems of our decentralized real world. Time is also a useful concept when considering possible causality. Consider a person suspected of a crime, if that person has an alibi because he or she was far enough away from the site of the crime at some instant close enough to the time of the crime, then he or she cannot be the culprit. Timing problems Accurate time is important to determining the order in which events occur; [3] this is a basic standard of transactional integrity, system and networkà ¢Ã¢â ¬Ã wide logging, auditing, troubleshooting and forensics. Having an accurate time source plays a critical role in tracing and debugging problems that occur on different platforms across a network. Events must be correlated with each other regardless of where they were generated. Furthermore, the notion of time (or time ranges) is used in many forms of access control, authentication, and encryption. In some cases, these controls can be bypassed or rendered inoperative if the time source could be manipulated. For example, a payroll function could be tricked into providing access over a weekend when normally it would be restricted to normal business hours. [3] Physical clocks Most computers today keep track of the passage of time with a battery-backed up Complementary Metal Oxide Semiconductor (CMOS) clock circuit, driven by a quartz resonator. This allows the timekeeping to take place even if the machine is powered off. When on, an operating system will generally program a timer circuit (a Programmable Interval Timer, or PIT, in older Intel architectures and Advanced Programmable Interrupt Controller, or APIC, in newer systems.) to generate an interrupt periodically (common times are 60 or 100 times per second). The interrupt service procedure simply adds one to a counter in memory. While the best quartz resonators can achieve an accuracy of one second in 10 years, they are sensitive to changes in temperature and acceleration and their resonating frequency can change as they age. Standard resonators are accurate to 6 parts per million at 31Ãâà °C, which corresponds to Ãâà ±Ãâà ½ second per day. The problem with maintaining a concept of time is when multiple entities expect each other to have the same idea of what the time is. Two watches hardly ever agree. Computers have the same problem: a quartz crystal on one computer will oscillate at a slightly different frequency than on another computer, causing the clocks to tick at different rates. The phenomenon of clocks ticking at different rates, creating an ever widening gap in perceived time is known as clock drift. The difference between two clocks at any point in time is called clock skew and is due to both clock drift and the possibility that the clocks may have been set differently on different machines. The Figure below illustrates this phenomenon with two clocks, A and B, where clock B runs slightly faster than clock A by approximately two seconds per hour. This is the clock drift of B relative to A. At one point in time (five seconds past five oclock according to As clock), the difference in time between the two clocks is approximately four seconds. This is the clock skew at that particular time. Compensating for drift We can envision clock drift graphically by considering true Coordinated Universal Time (UTC) flowing on the x-axis and the corresponding computers clock reading on the y-axis. A perfectly accurate clock will exhibit a slope of one. A faster clock will create a slope greater than unity while a slower clock will create a slope less than unity. Suppose that we have a means of obtaining the true time. One easy (and frequently adopted) solution is to simply update the system time to the true time. To complicate matters, one constraint that well impose is that its not a good idea to set the clock back. The illusion of time moving backwards can confuse message ordering and software development environments. If a clock is fast, it simply has to be made to run slower until it synchronizes. If a clock is slow, the same method can be applied and the clock can be made to run faster until it synchronizes. The operating system can do this by changing the rate at which it requests interrupts. For example, suppose the system requests an interrupt every 17 milliseconds (pseudo-milliseconds, really the computers idea of what a millisecond is) and the clock runs a bit too slowly. The system can request interrupts at a faster rate, say every 16 or 15 milliseconds, until the clock catches up. This adjustment changes the slope of the system time and is known as a linear compensating Function. After the synchronization period is reached, one can choose to resynchronize periodically and/or keep track of these adjustments and apply them continually to get a better running clock. This is analogous to noticing that your watch loses a minute every two months and making a mental note to adjust the clock by that amount every two months (except the system does it continually). Synchronizing physical clocks With physical clocks, our interest is not in advancing them just to ensure proper message ordering, but to have the system clock keep good time. We looked at methods for adjusting the clock to compensate for skew and drift, but it is essential that we get the time first so that we would know what to adjust. One possibility is to attach a GPS (Global Positioning System) receiver to each computer. A GPS receiver will provide time within Ãâà ± 1 msec. of UTC time but Unfortunately, they rarely work indoors. Alternatively, if the machine is in the U.S., one can attach a WWV radio receiver to obtain time broadcasts from Texas, Colorado or Washington, DC, giving accuracies of Ãâà ± 3-10 msec. depending on the distance from the source. Another option is to obtain a GOES (Geostationary Operational Environment Satellites) receiver, which will provide time within Ãâà ± 0.1 msec. of UTC time. For reasons of economy, convenience, and reception, these are not practical solutions for every machine. Most machines will set their time by asking another machine for the time (preferably one with one of the aforementioned time sources). A machine that provides this information is called a time server. Several algorithms have been proposed for synchronizing clocks and they all have the same underlying model of the system Cristians algorithm The simplest algorithm for setting the time would be to simply issue a remote procedure call to a time server and obtain the time. That does not account for the network and processing delay. We can attempt to compensate for this by measuring the time (in local system time) at which the request is sent (T0) and the time at which the response is received (T1). Our best guess at the network delay in each direction is to assume that the delays to and from are symmetric (we have no reason to believe otherwise). The estimated overhead due to the network delay is then (T1- T0)/2. The new time can be set to the time returned by the server plus the time that elapsed since the server generated the timestamp: Suppose that we know the smallest time interval that it could take for a message to be sent between a client and server (either direction). Lets call this time Tmin. This is the time when the network and CPUs are completely unloaded. Knowing this value allows us to place bounds on the accuracy of the result obtained from the server. If we sent a request to the server at time T0, then the earliest time stamp that the server could generate the timestamp is T0 + Tmin. The latest time that the server could generate the timestamp is T1 Tmin, where we assume it took only the minimum time, Tmin, to get the response. The range of these times is: T1 T0 2Tmin, so the accuracy of the result is: Errors are cumulative. If machine A synchronizes from a server B and gets an accuracy of Ãâà ±5 msec but server B in turn got its time from server C with an accuracy of Ãâà ±7 msec, the net accuracy at machine A is Ãâà ±(5+7), or Ãâà ±12 msec. Several time requests may be issued consecutively in the hope that one of the requests may be delivered faster than the others (e.g., it may be submitted during a time window when network activity is minimal). This can achieve improved accuracy. Cristians algorithm suffers from the problem that afflicts all single-server algorithms: the server might fail and clock synchronization will be unavailable. It is also subject to malicious interference. Berkeley algorithm The Berkeley algorithm, developed by Gusella and Zatti in 1989 [8], is form of an internal synchronization that does not assume that any machine has an accurate time source with which to synchronize. Instead, it opts for obtaining an average time from the participating computers and synchronizing all machines to that average. The machines involved in the synchronization each run a time dà ¦mon process that is responsible for implementing the protocol. One of these machines is elected (or designated) to be the master. The others are slaves. The server polls each machine periodically, asking it for the time. The time at each machine may be estimated by using Cristians method to account for network delays. When all the results are in, the master computes the average time (including its own time in the calculation). The hope is that the average cancels out the individual clocks tendencies to run fast or slow. Instead of sending the updated time back to the slaves, which would introduce further uncertainty due to network delays, it sends each machine the offset by which its clock needs adjustment. The operation of this algorithm is illustrated in the Figure below. Three machines have times of 3:00, 3:25, and 2:50. The machine with the time of 3:00 is the server (master). It sends out a synchronization query to the other machines in the group. Each of these machines sends a timestamp as a response to the query. The server now averages the three timestamps: the two it received and its own, computing (3:00+3:25+2:50)/3 = 3:05. Now it sends an offset to each machine so that the machines time will be synchronized to the average once the offset is applied. The machine with a time of 3:25 gets sent an offset of -0:20 and the machine with a time of 2:50 gets an offset of +0:15. The server has to adjust its own time by +0:05. The algorithm also has provisions to ignore readings from clocks whose skew is too great. The master may compute a fault-tolerant average averaging values from machines whose clocks have not drifted by more than a certain amount. If the master machine fails, any other slave could be elected to take over Logical clocks Lets again consider cases that involve assigning sequence numbers (timestamps) to events upon which all cooperating processes can agree. What matters in these cases is not the time of day at which the event occurred but that all processes can agree on the order in which related events occur. Our interest is in getting event sequence numbers that make sense system-wide. If we can do this across all events in the system, we have something called total ordering: every event is assigned a unique timestamp (number), every such timestamp is unique. However, we dont always need total ordering. If processes do not interact then we dont care when their events occur. If we only care about assigning timestamps to related (causal) events then we have something known as partial ordering. Leslie Lamport [7] developed a happened before notation to express the relationship between events: aà ¢Ã¢â¬ ââ¬â¢b means that a happened before b. If a represents the timestamp of a message sent and b is the timestamp of that message being received, then aà ¢Ã¢â¬ ââ¬â¢b must be true; a message cannot be received before it is sent. This relationship is transitive. If aà ¢Ã¢â¬ ââ¬â¢b and bà ¢Ã¢â¬ ââ¬â¢c then aà ¢Ã¢â¬ ââ¬â¢c. If a and b are events that take place in the same process the aà ¢Ã¢â¬ ââ¬â¢b is true if a occurs before b. The importance of measuring logical time is in assigning a time value to each event such that everyone will agree on the final order of events. That is, if aà ¢Ã¢â¬ ââ¬â¢b then clock (a) < clock (b) since the clock (our timestamp generator) must never run backwards. If a and b occur on different Processes that do not exchange messages (even through third parties) then aà ¢Ã¢â¬ ââ¬â¢b is not true, these events are said to be concurrent: there is no way that a could have influenced b. Each event is assigned a timestamp by its respective process. The process simply maintains a global counter that is incremented before each event gets a timestamp. If we examine the timestamps from our global perspective, we can observe a number of peculiarities. Event g, the event representing the receipt of the message sent by event a, has the exact same timestamp as event a when it clearly had to take place after event a. Event e has an earlier time stamp (1) than the event that sent the message (b, with a timestamp of 2). Lamports algorithm Lamport [7] proposed an algorithm that forces the resequencing of timestamps to ensure that the happened before relationship is properly depicted for events related to sending and receiving messages. It works as follows: Each process has a clock, which can be a simple counter that is incremented for each event. The sending of a message is an event and each message carries with it a timestamp obtained from the current value of the clock at that process (sequence number). The arrival of a message at a process is also an event will also receive a timestamp by the receiving process, of course. The process clock is incremented prior to time stamping the event, as it would be for any other event. If the clock value is less than the timestamp in the received message, the systems clock is adjusted to the (messages timestamp + 1). Otherwise nothing is done. The event is now time stamped. If we apply this algorithm to the same sequence of messages, we can see that proper message ordering among causally related events is now preserved. Note that between every two events, the clock must tick at least once. [4] Lamports algorithm [7] allows us to maintain proper time ordering among causally- related events. In summary, Lamports algorithm requires a monotonically increasing software counter for a clock that has to be incremented at least when events that need to be time stamped take place. These events will have the clock value, or Lamport timestamp, associated with them. For any two events, where aà ¢Ã¢â¬ ââ¬â¢b, L (a) < L (b) where L(x) represents the Lamport timestamp for event x. Lamport timestamps [7] assure us that if there is a causal relationship between two events, then the earlier event will have a smaller time stamp than the later event. Causality is achieved by successive events on one process or by the sending and receipt of messages on different processes. As defined by the happened-before relationship, causality is transitive. For instance, events a and f are causally related in the figure above (through the sequence a, b, e, f). Implementing Logical clocks To implement logical clocks, [11] each process p, maintains data structures that give it the following two capabilities: A logical clock, denoted by C, that helps P, measure its own progress; and A global logical clock denoted by gC, that represents Ps local view of the global logical time. A protocol is presented to update the data structures; the protocol ensures that a processs logical clock and its view of the global time are consistent. The protocol consists of the following two rules: R1. maintains how a process updates the local logical clock when it executes an Event, whether send or receive R2. maintains how a process updates its global logical clock to update its view of the Global time. It dictates what information about the logical time a process Piggybacks in a message and how the receiving process uses this information to Update its view of the global time A distributed system consisting of logical clocks differ in their representation of logical time and in the protocol for updating logical clocks. However, all systems consisting of logical clocks implements some form of R1 and R2 and thereby achieving the fundamental monotonicity property associated with events and casualty Total ordering of events Note that it is very possible for multiple non-causal (concurrent) events to share identical Lamport timestamps (e.g., c, e, and h in the Figure above). This may cause confusion if multiple processes need to make a decision based on the timestamps of two events. The selection of a specific event may not matter if the events are concurrent but we want all the processes to be able to make the same decision. This is difficult if the timestamps are identical. Fortunately, theres an easy remedy. We can create a total order on events by further qualifying them with identities of processes. We define a global logical timestamp (Ti,i) where Ti represents the local Lamport timestamp and i represents the process ID (in some globally unique way: for example, a concatenation of host address and process ID). We are then able to globally compare these timestamps and conclude that There is no physical significance to the order since process identifiers can be arbitrary and do not relate to event ordering but the ability to ensure that no two Lamport timestamps are the same globally is helpful in algorithms that need to compare these timestamps. In real life, depending on the application, one may use a combination of thread ID, process ID, and IP address as a qualifier to the timestamp. Vector clocks If two events are causally related and event e happened before event e then we know that L (e) < L (e). However, the converse is not necessarily true. With Lamports algorithm, if L (e) < L (e) we cannot conclude that eà ¢Ã¢â¬ ââ¬â¢e. Hence, if we look at Lamport timestamps, we cannot conclude which pairs of events are causally related and which are not. One solution that has been proposed to deal with this problem is the concept of vector clocks (proposed by Mattern in 1989 and Fidge in 1991) [9, 10]. A vector clock in a system of N processes is a vector of N integers. Each process maintains its own vector clock (Vi for a process Pi) to timestamp local events. Like Lamport timestamps, vector timestamps (the vector of N integers) are sent with each message. The rules for using vector clocks are: The vector is initialized to 0 at all processes: Vi[j] = 0 for i,j = 1, à ¢Ã¢â ¬Ã ¦, N Before a process Pi timestamps an event, it increments its element of the vector in its local vector: Vi[i] = Vi[i]+1 A message is sent from process Pi with Vi attached to the message. When a process Pj receives a vector timestamp t, it compares the two vectors element by element, setting its local vector clock to the higher of the two values: Vj[i] = max(Vj[i], t[i]) for i=1, à ¢Ã¢â ¬Ã ¦, N We compare two vector timestamps by defining: V = V iff V[j] = V'[j] for i=1, à ¢Ã¢â ¬Ã ¦, N V à ¢Ã¢â¬ °Ã ¤ V iff V[j] à ¢Ã¢â¬ °Ã ¤ V'[j] for i=1, à ¢Ã¢â ¬Ã ¦, N For any two events e, e, if eà ¢Ã¢â¬ ââ¬â¢e then V(e) < V(e). This is the same as we get from Lamports algorithm. With vector clocks, we now have the additional knowledge that if V(e)
Subscribe to:
Posts (Atom)