The following piece of literature Essay Example For Students

The following piece of literature Essay The following piece of literature is a guide for the management of Ernest Naylor regarding the system created to model the current activities of the organisation. In addition to this, a prototype database was created that could form the basis of a full scale model to aid in the activities within the organisation which have been modeled in detail in the following report. Each stage in the modeling of the system includes a diagram for the ease of understanding of the processes involved and each diagram is accompanied by a small description summarising the activities described in the diagram. Rational Rose was used to model the system as it allows for a greater understanding of the system and is a simple method that can be easily followed to provide an in depth study of the system and its environment. Other possibilities to model the system included Structured Systems Analysis and Design. However it was felt that modeling the system using the Unified Modelling Language (UML) would be more beneficial due to its adaptability and understandability for the user. We will write a custom essay on The following piece of literature specifically for you for only $16.38 $13.9/page Order now Criticism of methods used SSADM was very successful, any methodology that attempts this degree of coordination tends to grow large and unwieldy, partly due to the need for continual checking and cross-referencing between separate models. Object Modeling Techniques (OMT), class diagram notation was incorporated into UML almost unaltered. But, unlike UML, OMT is more than a language, or set of techniques and notations. Both the OMT and Structured System Analysis and Design (SSADM), consist of similar modeling components. They both support the same views of a system: the object, functional and dynamic models. The differences between them are the emphasis and style. In SSADM, the dominating view is the functional model whereas in the UML it is the object model. OMT organises the system around the real world objects, compared to the SSADM, which organises the system around procedures. Changes in requirements cause problems for SSADM because procedure based designs do not reflect change easily, this also causes problems with extendibility to the system, whereas the OMT can accommodate the change easier and extendibility can be implemented. In Object-Oriented Analysis (OOA) the users and developers of the system are brought together, uniting them with a common vocabulary drawn from the domain. In the object-orientated approach the system is designed with the context of real world objects in mind. Object Orientated Methods including UML have evolved to help developers exploit their expressive power (Coad and Yourdon 1991) . Some of the benefits are listed below: Use cases show the functionality of the system from the users perspective. They document the scope of the system and the developers understanding of what it is that the users require. The use cases diagram shown below has three aspects of the system: actors, use cases and the system boundary. Actors represent the roles that people take on when communicating with the particular use cases in the system. One actor can represent several people or job titles. In the diagram shown below, OrderClerk is an actor and the order material is the use case. Use cases can provide a step-by-step breakdown of the interaction between the user and the system for each particular use case. Class Diagram The class diagram is derived from the use case and is developed for each use case. We know from the use case diagram that the OrderClerk is the actor for the use case order material. The use case description tells us that the clerk is responsible for ordering materials. As you can see below, class names are always written in the singular, for example, for the class name customer, it can be seen below that it is written in singular although there are many number of customers. .ubf74a7adcacfe4126dd5336608cade35 , .ubf74a7adcacfe4126dd5336608cade35 .postImageUrl , .ubf74a7adcacfe4126dd5336608cade35 .centered-text-area { min-height: 80px; position: relative; } .ubf74a7adcacfe4126dd5336608cade35 , .ubf74a7adcacfe4126dd5336608cade35:hover , .ubf74a7adcacfe4126dd5336608cade35:visited , .ubf74a7adcacfe4126dd5336608cade35:active { border:0!important; } .ubf74a7adcacfe4126dd5336608cade35 .clearfix:after { content: ""; display: table; clear: both; } .ubf74a7adcacfe4126dd5336608cade35 { display: block; transition: background-color 250ms; webkit-transition: background-color 250ms; width: 100%; opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #95A5A6; } .ubf74a7adcacfe4126dd5336608cade35:active , .ubf74a7adcacfe4126dd5336608cade35:hover { opacity: 1; transition: opacity 250ms; webkit-transition: opacity 250ms; background-color: #2C3E50; } .ubf74a7adcacfe4126dd5336608cade35 .centered-text-area { width: 100%; position: relative ; } .ubf74a7adcacfe4126dd5336608cade35 .ctaText { border-bottom: 0 solid #fff; color: #2980B9; font-size: 16px; font-weight: bold; margin: 0; padding: 0; text-decoration: underline; } .ubf74a7adcacfe4126dd5336608cade35 .postTitle { color: #FFFFFF; font-size: 16px; font-weight: 600; margin: 0; padding: 0; width: 100%; } .ubf74a7adcacfe4126dd5336608cade35 .ctaButton { background-color: #7F8C8D!important; color: #2980B9; border: none; border-radius: 3px; box-shadow: none; font-size: 14px; font-weight: bold; line-height: 26px; moz-border-radius: 3px; text-align: center; text-decoration: none; text-shadow: none; width: 80px; min-height: 80px; background: url(https://artscolumbia.org/wp-content/plugins/intelly-related-posts/assets/images/simple-arrow.png)no-repeat; position: absolute; right: 0; top: 0; } .ubf74a7adcacfe4126dd5336608cade35:hover .ctaButton { background-color: #34495E!important; } .ubf74a7adcacfe4126dd5336608cade35 .centered-text { display: table; height: 80px; padding-left : 18px; top: 0; } .ubf74a7adcacfe4126dd5336608cade35 .ubf74a7adcacfe4126dd5336608cade35-content { display: table-cell; margin: 0; padding: 0; padding-right: 108px; position: relative; vertical-align: middle; width: 100%; } .ubf74a7adcacfe4126dd5336608cade35:after { content: ""; display: block; clear: both; } READ: Essay on A Dolls HouseAttributes are part of the essential description of a class. Examples of these are: Name, CompanyName and etc, for the class surveyor. They are the common structure of what a member can know. This means, a member can know the name of the surveyor and the company name too. A class is sub-divided into three compartments: the top compartment contains the class name, the second contains the attribute names and the third contains operations. Operations are the action that is carried out by an object. An example of an operation for the class diagram customer is Add New. This allows new customers to be added to the system. Interaction Diagrams 1. Complete Estimate Sequence Diagram for Surveyor: A sequence diagram shows an interaction between objects, arranged in a time sequence. Its most common use is to represent the detailed object interaction that occurs for one use or one operation. It specifies the communication patterns between the roles in collaboration.

Law of Constant Composition Lab Essay Essays

Law of Constant Composition Lab Essay Essays Law of Constant Composition Lab Essay Paper Law of Constant Composition Lab Essay Paper Purpose: To find the per centum Mg by mass in Mg oxide and to detect if the per centum composing is changeless by comparing category consequences. Hypothesis/Prediction: The per centum composing by mass of Mg in Mg oxide will non alter significantly with each group that conducted the experiment. The composing of each substance should remain the same and any differences must be due to some mistake. Materials: Magnesium stripCrucibleCrucible coverClay triangleIron ringRetort standTongsBalanceBunsen burnerProcedure:1. obtained a strip of Mg between 30-40 centimeter long2. coiled Mg strip into a tight roll3. measured the mass of the crucible and cover4. Added the Mg strip to the crucible and measured the Mg. crucible and cover together. 5. Partially covered the crucible with the screen and heated it utilizing a Bunsen burner until the Mg ignited. 6. Turned off Bunsen burner. 7. waited for burning to proceed8. when the reaction appeared completed. heated the melting pot once more for another five minutes9. allowed crucible to chill for 10 minutes10. measured the mass of the crucible. screen and magnesium oxideObservations: When ignited. the Mg strip gave off a bright visible radiation. There was a color alteration on the Mg. It started out as Ag and turned into a white coloring material. The burning gave off a distinguishable smell. The terminal consequence was a white pulverization but some Mg had been left in its original form. Harmonizing to the theory of J. L. Proust. a compound ever has the same per centum composing no affair how it is prepared. For all three of our ain single groups tests. we obtained the same per centum composing and this satisfies Prousts theory. This is besides accurate with what we have read in the text edition Chemistry 11 on the Law of Definite Proportions on pages 147 150. 2. What decision can you do upon the category consequences? The decisions I can do based upon the category consequences are that the composing of a compound must change because everyone had a different reply. In most instances. the per centum composing of Mg in the compound was really different from what my group achieved. However. sometimes. the categories consequences were rather similar to my ain. The theory that C. M. Berthollet introduced about the composing of a compound was that a compound has an infinite figure of composings depending on the proportions of the constituents that were used in its readying. His theory satisfies the consequences obtained from the whole category. Since every group had a different sum of Mg they must besides hold had a different composing of Mg in the compound formed. Mg oxide. However. this is inconsistent with what we have been taught and with what is written in the text edition. Since the text edition is a more dependable beginning of information. I must reason that the ground for this difference in consequences may be attributed to error on the portion of the pupils carry oning the experiment. 3. Which Gallic Scientist would you be given to back up? Explain. The Gallic scientist that I support is J. L. Proust. I agree with Marcel prousts theory because I believe that if the composing of a substance were to alter. so would its belongingss. An obvious illustration of this is one stated in the text edition: H2O and H peroxide. The simple add-on of a H atom to the compound of H2O can do a liquid that is indispensable to life go lifelessly. Since I know that the per centum composing of a peculiar substance is the same no affair where. how or when it is made. I must hold with J. L Proust and back up his theory. Beginnings of ErrorOne ground why a pupil may hold obtained a higher per centum of Mg than the remainder of the category is: during the experiment. mass must hold been lost. This could hold been done in many ways. Often. the Mg took excessively long to light and pupils began to set it directly into the fire to light it and so put it back into the crucible. Sometimes. the Mg wilted and small pieces of it broke off. In add-on. the Mg would sometimes light and so snuff out itself. In the changeless remotion of the Mg from the crucible. mass was lost in the signifier of ashes. When mass is lost during the experiment. the entire mass of the compound is lower and when the mass of Mg was divided by the entire mass. yielded a higher per centum of Mg. One ground why a pupil may hold obtained a lower per centum of Mg than the remainder of the category is: the Mg did non decently combust. In many instances. the Mg would snuff out itself and would non fire wholly. This resulted in some white pulverization. ash. and some Mg still in the same form that it was when we began the experiment. This suggests that it did non fire with the remainder of the Mg thread and hence. did non organize the compound with O. This would give in a higher entire mass than what it should hold been and when the mass of Mg is divided by the entire mass. would give a lower per centum. The undermentioned computation shows the existent per centum of Magnesium in the compound Mg oxide. Molar mass of MgO = 24. 3 + 16. 0= 40. 3For 1. 00 mol of MgO: % Mg = 24. 3 / 40. 3 ten 100= 60. 3 % Therefore. the existent per centum value of Mg in MgO is 60 % The undermentioned computation shows the per centum mistake for my ain groups result % mistake = ( experimental accepted ) / accepted ten 100= ( 72 60 ) / 60 ten 100= 20 % Therefore the per centum mistake for my group was 20 % . ConclusionBased on the informations collected by each group. the composing of a substance must alter depending on the proportions of the constituents that were used in its readying. However. as explained earlier. the text edition and the belongingss of affair province otherwise. Scientifically. if the composing of a compound was to alter. so would its belongingss. The consequences obtained by the category are rather the antonym of what has already been proven by Proust to be true and hence. I believe that the grounds obtained by our chemical science category is the consequence of many errors and can non be used to convey the thought of the Law of Constant Composition which states that the composing of a specific compound is changeless.