Principal Components and Factor Analysis

Principal Components and Factor Analysis Principal components analysis (PCA) and factor analysis (FA) are statistical techniques used for data reduction or structure detection. These two methods are applied to a single set of variables when the researcher is interested in discovering which variables in the set form coherent subsets that are relatively independent of one another. Variables that are correlated with one another but are largely independent of other sets of variables are combined into factors. These factors allow you to condense the number of variables in your analysis by combining several variables into one factor. The specific goals of PCA or FA are to summarize patterns of correlations among observed variables, to reduce a large number of observed variables to a smaller number of factors, to provide a regression equation for an underlying process by using observed variables, or to test a theory about the nature of underlying processes. Example Say, for example, a researcher is interested in studying the characteristics of graduate students. The researcher surveys a large sample of graduate students on personality characteristics such as motivation, intellectual ability, scholastic history, family history, health, physical characteristics, etc. Each of these areas is measured with several variables. The variables are then entered into the analysis individually and correlations among them are studied. The analysis reveals patterns of correlation among the variables that are thought to reflect the underlying processes affecting the behaviors of the graduate students. For example, several variables from the intellectual ability measures combine with some variables from the scholastic history measures to form a factor measuring intelligence. Similarly, variables from the personality measures may combine with some variables from the motivation and scholastic history measures to form a factor measuring the degree to which a stude nt prefers to work independently – an independence factor. Steps of Principal Components Analysis and Factor Analysis Steps in principal components analysis and factor analysis include: Select and measure a set of variables.Prepare the correlation matrix to perform either PCA or FA.Extract a set of factors from the correlation matrix.Determine the number of factors.If necessary, rotate the factors to increase interpretability.Interpret the results.Verify the factor structure by establishing the construct validity of the factors. Difference Between Principal Components Analysis and Factor Analysis Principal Components Analysis and Factor Analysis are similar because both procedures are used to simplify the structure of a set of variables. However, the analyses differ in several important ways: In PCA, the components are calculated as linear combinations of the original variables. In FA, the original variables are defined as linear combinations of the factors.In PCA, the goal is to account for as much of the total variance in the variables as possible. The objective in FA is to explain the covariances or correlations among the variables.PCA is used to reduce the data into a smaller number of components. FA is used to understand what constructs underlie the data. Problems with Principal Components Analysis and Factor Analysis One problem with PCA and FA is that there is no criterion variable against which to test the solution. In other statistical techniques such as discriminant function analysis, logistic regression, profile analysis, and multivariate analysis of variance, the solution is judged by how well it predicts group membership. In PCA and FA, there is no external criterion such as group membership against which to test the solution. The second problem of PCA and FA is that, after extraction, there is an infinite number of rotations available, all accounting for the same amount of variance in the original data, but with the factor defined slightly different. The final choice is left to the researcher based on their assessment of its interpretability and scientific utility. Researchers often differ in opinion on which choice is the best. A third problem is that FA is frequently used to â€Å"save† poorly conceived research. If no other statistical procedure is appropriate or applicable, the data can at least be factor analyzed. This leaves many to believe that the various forms of FA are associated with sloppy research.

Advances in accounting Essay Example | Topics and Well Written Essays - 1000 words

Advances in accounting - Essay Example This research seeks to determine the relevance of OBA in an environment with high competition and the lack of cooperation between the suppliers and consumers. Most companies after exploiting most of the cost reduction methods have resorted to forming supply chains to be competitive in the market. With this, OBA was found to be necessary for reducing cost and thus raised productivity. For OBA to be successful, it requires cooperation and mutual trust between the suppliers and consumers. The researchers have noted that most companies are not willing to share important information with the buyers. This paper is important since it seeks to address the importance and challenges facing the application of OBA technique in inter-organizational cost management. Despite the challenging circumstances under which OBA is applied, the paper addresses how it can be used for the good of the parties involved and also give recommendations on how to counter the challenges involved. The paper is interesting since it involves interacting with people in the real market situation, and the findings thereof are a true reflection of what is happening in the field. The key reference literatures for this research are vi. Sharing Sensitive Information in Supply Relationships: The Flaws in One-way Open-book Negotiation and the Need for Transparency, European Management Journal by Lamming, Richard, Nigel D. Caldwell, Wendy E. Phillips, and Deborah A. Harrison (2005) The above books describe the relevance of OBA to cost reduction and the conditions for the success of the tool to cost management in IOCM. These books seek to describe the challenges facing the implementation of OBA in inter-organization cost management. The research method chosen for the study is interview. This involved interviewing purchasing experts in the first and second phases and afterward interviewed sales experts. These interviews were done using questionnaires, whereby the questionnaires were sent to

Tool mark Examination Physical Criminalistics Lab Report

Tool mark Examination Physical Criminalistics - Lab Report Example Tools can include the usual instruments such as screwdrivers, drill bits, hummer, pry bars and punch or other substances such as rocks. Different tools will create different impressions or marks but each tool creates an impression that is unique to itself. Tools and their impressions are largely defined by the manufacturing process that was used in production and thus lab scientists should be familiar with the various manufacturing processes including casting, forging, extrusion, machining and others. Also certain manufacturing process produce marks that change with time due to wearing of the cutting tool when in contact with the work piece (Monturo, 2010, p 8). Ductile materials may also develop built up edges during machining when the material cold welds onto the tool cutting edge due to high pressures resulting from the process. As more pressure is applied, the built up edge breaks off and the new material replaces the edge and thus the change in the cutting surface is used to examine the manufactured tools and their marks. The main types of marks that are created by different tools including impressed marks such as hammer strikes and striated marks such as the marks made when a screwdriver slides over a soft surface (Association of Firearms and Tool Mark Examiners, 2007).The toolmarks are further classified according to their class and subclass properties. Tools also have individual characteristics including random imperfections resulting from the manufacturing process, corrosion or damage (Association of Firearms and Tool Mark Examiners, 2007). Class characteristic features are defined before the manufacture of the tool and include its shape and size and the type of impression that is imparted by the tool including shearing, slicing, compression and crimping (Association of Firearms and Tool Mark Examiners, 2007, p 8). Subclass properties are in most situations confused with the individual characteristics. They are the

Social and Environmental Accounting Research Paper

Social and Environmental Accounting - Research Paper Example This report states, Western Australia has implemented a water minimization program in 1997 and its implementation led to the reduction of usage of water, saved the company thousands of dollars and reduced their level of reliance on the water that is supplied by the municipal council. The objective of implementing this program was to optimize the water supply and also reduce the rate of consumption of poor quality drinking water that could be a health hazard to the residents of the area and minimize the flow of untreated waste water that was being discharged to the environment (BP, 2006). BP refinery processes over 138 barrels of oil per day .The refinery equipments and machinery ensures that the raw materials are processed into complete finished products. The management of the company found it worthwhile to be conservative after becoming more water conscious and water efficient. BP implemented various strategies that were aimed at improving the rate of performance within the organization. The strategy includes; delivery of water that is of high quality for consumption, minimizing on the cost of running the operations of the organization and maximizes the profits of the organization. It also minimizes the potential environmental risks from water that is being dis charged from the environment (Bp, 2006). The managemenThe management of the BP Company published the sustainable report 2007, addressed issues that are related to the observance and recognisition of the audience as important persons within the community. It also states that the major stakeholders' role within the community involves meeting the needs and wants of the customers within the stipulated period of time. The major stakeholders include academicians, investors and other non-governmental organizations (Appendix 1, Bp, 2007, cover page). BP sustainability refers to the capacity to endure and meet the needs of the people through renewing their assets, creating and delivering different kinds of products and services that can meet the needs of the people within a given period of time. It also refers to the process of ensuring that the rights of people are respected and observed in order to enable them carry out the tasks that have been assigned to them and also ensure that the operations and activities carried are undertaken in the appropriate manner. Moreover, Bp also ensures that the mutual trust and support that is bestowed on the customers, shareholders and the communities is maintained so that the activities of the company can continue into the foreseeable future (Burke, 1999). In similarity to BP water minimization program, Thames report was prepared and aimed at identifying the cause and solutions of flooding observed in Bowmonts Road. This report states the impact of the proposed development in River Tadley that would have been undertaken on the network. Besides that, is also intended to identify the options that can alleviate foul flooding in the region and also to provide the cost estimates for options

Database Design And Development For Petcare Veterinary Computer Science Essay

Database Design And Development For Petcare Veterinary Computer Science Essay Draw an Entity Relationship Data Model that describes the content and structure of data held by PetCare. Specify the cardinality ratio and participation constraint of each relationship type. Database Development Process The process is divided into four main stages: requirements elicitation, conceptual modeling, logical modeling and physical modelling. The techniques used in the development process naturally divide into three categories: those concerned modelling, those concerned with logical modelling and those concerned with physical modelling. Figure 1 the database development process Requirements Elicitation Requirements elicitation involves establishing the key technical requirements for a database system usually through formal and informal interaction between developers and organizational stakeholders such as users. It provides the structure of data needed and the use of the data in some information system context. Stakeholder identification and participation One of the first things that must be done in any information systems project is to identify the relevant stakeholders. A stakeholders group is any social group within and without the organization that potentially may influence the successful use and impact of the database system. Veterinary doctor Use the database to for managing treatment information of pet Staff keep track of animal and appointment Regulators National and regional government may need to audit the database Requirements Elicitation and requirements specification Requirements elicitation is the precursor to requirements specification. In terms of a system to manage Petcare, the following is a list of proposed requirements for system: The database should be capable of supporting the following transaction: Create and maintain records recording the details of Petcare Pets clinics and the members of staff at each clinic. Create and maintain records recording the details of pet owners. Create and maintain the details of pets. Create and maintain records recording the details of the types of treatments for pets. Create and maintain records recording the details of examinations and treatments given to pets. Create and maintain records recording the details of invoices to pet owners for treatment to their pets. Create and maintain pet owner/pet appointments at each clinic. Data requirements PetCare veterinary surgery Petcare has six medium sized veterinary surgery clinics across London. The details of each clinic include address of branch, telephone number, opening hours and emergency contact telephone number. Assuming that each clinic has a number of staff for example vets, nurses, secretaries and cleaners. Staff The details stored on each member of staff include the staff name, address, home telephone number and mobile telephone number. Pet owners When a pet owner first contacts a clinic of Petcare the details of the pet owner are recorded, which include name, address, home telephone number and mobile telephone number. Pets The details of the pet requiring treatment are noted, which include a put number, type of pet, age and sex. Examinations When a sick pet is brought to a clinic, the vet on duty examines the pet. The details of each examination are recorded and include an examination number, the date and time of the examination, the name of the vet, the pet number, pet name, and type of pet, and a full description of the outcome of the examination results. Petcare provides various treatments for all types of pets. The details of each treatment include a treatment number, full description of the treatment, and the cost to the pet owner. Based on the result of the examination of a sick pet, the vet may propose one or more types of treatment. For each types of treatment, the information recorded includes the examination number and date. Invoices The pet owner is responsible for the cost of the treatment given to a pet. The owner is invoiced for the treatment arising from each examination, and the details recorded on the invoice include the invoice number, invoice date, owner number, owner name and full address, put number, put name, and details of the treatment given. The invoice provides the cost for each type of treatment and total cost of all treatments given to the pet. Additional data is also recorded on the payment for example cash, credit card or check. Appointments If the pet requires to be seen by the vet at later date, the owner and pet are given an appointment. The details of an appointment are recorded and include an appointment number, owner name, date and time. Using the logical database design methodology Entity-Relationship modeling is a top-down approach to database design. We begin ER modeling by identifying the important data (called entities) and relationships between the data that must be represented in the model. We then add more details such as the information we want to hold about the entities and relationships (called attributes) and any constraints on the entities, relationships, and attributes. Identify entities Identify entities A set of objects with the same properties, which are identified by a user or organization as having an independent existence The first step in logical database design is to identify entity that you have to represent in the database. Entity name Description Occurrence Clinic Veterinary clinics One or more Petcare clinics located throughout London Staff General term describing all staff employed by Petcare Each member of staff works at a particular clinic PetOwner Owners of pets taken to Petcare Owner takes his/her pet to a particular clinic Pet Sick animal seek treatment to the clinic One or more animal are taken to the clinic Examination Treatment Invoice Appointment PetTreatment Attributes The particular properties of entities are called attributes. Attributes represent what we want to know about entities. Single-Valued attributes The majority of attributes are single-valued for a particular entity. For example, each occurrence of the Staff entity has a single value for the staffNo attribute (for example,001), and therefore the staffNo attribute is referred to as being single-valued. Derived attributes An attributes that represents a value that is derivable from the value of a related attributes, or set of attributes, no necessarily in the same entity. Some attributes may be related for a particular entity. For example, the age of a pet is derivable form the date of birth (DOB) attribute, and therefore the age and DOB attributes are related. We refer the age attributes as a derived attributes, the value of which is derived from the DOB attribute. Age is not normally stored in a database because it would have to be updated regularly. On the other hand, as date of birth never changes and age can be derived from date of , date of birth is stored instead, and age is derived from DOB attribute, when needed. Identify relationships Having identifies the entities; next step is to identify all the relationships that exist between these entities. A relationship is a set of associations between participating entities. As with entities, each association should be uniquely identifiable within the set. A uniquely identifiable associations is called a relationships occurrence Clinic Relationships Entity Relationship Entity Clinic Has Veterinary Registers Pet Schedules Appointment IsContactedBy PetOwner Veterinary Relationships Entity Relationship Entity Veterinary Performs Examination Pet Owner Relationships Entity Relationship Entity PetOwner Owns Pet Pays Invoice Attends Appointment Pet Relationships Entity Relationship Entity Pet Undergoes Examination Attends Appointment Cardinality Ratio of PetCare database Cardinality or degree concerns the number of instances involved in a relationship. A relationship can be said to be either a 1:1 (one-to-one) relationship, a 1: M (one-to-many) relationship, or an M: N (many-to-many) relationship. Final Clinic relationships Entity Cardinality Relationship Cardinality Entity Clinic 1..1 Has 1..M Staff 1..M Registers 1..M Pet 1..1 Schedules 1†¦M Appointment 1..1 IsContactedBy 1..M PetOwner Final Veterinary Relationships Entity Cardinality Relationship Cardinality Entity Veterinary 1..1 Performs 1..M Examination Final Pet Owner Relationships Entity Cardinality Relationship Cardinality Entity PetOwner 1..1 Owns 1..M Pet 1..1 Pays 1..M Invoice 1..1 Attends 1..M Appointment Final Pet Relationships Entity Cardinality Relationship Cardinality Entity Pet 1..1 Undergoes 1..M Examination 1..1 Attends 1..M Appointment First draft Entity Relationship Data Model Second draft Entity Relationship Data Model Final Entity Relationship Data Model Task 2 Normalization Normalization is a technique for producing a set of table with desirable properties that support the requirements of a user or company. There are several normal forms, although the most ones are called first normal form (1NF), second normal form (2NF), and third normal form (3NF). All these normal forms are based on rules about relationships among the columns of a table. First normal forms (1NF) Only first normal form (1NF) is critical in creating appropriate tables for relational databases. All the subsequence normal forms are optional. A table in which the intersection of every column and record contains only one value Clinic (clinicNo, address, city, state, zipcode, telNo, faxNo, opeingHour) Primary Key clinicNo Alternate Key zipCode Alternate Key telNo Alternate Key faxNo Alternate Key opeingHour clinicNo address telNo openingHour C001 Enfield 503-555-3618, 503-555-2727, 503-555-6534 9.00-21-00 C002 Islington 206-555-6756, 206-555-8836 9.00-21-00 C003 Hackney 212-371-3000 9.00-21-00 C004 Holloway 206-555-3131, 206-555-4112 9.00-21-00 C005 Chingford 8502333 9.00-21-00 C006 Leyton 4650000 9.00-21-00This version of the Clinic table is not in 1NF More than one value, so not in 1NF Converting to 1NF To convert this version of the Clinic table to 1NF, we create separate table called ClinicTelephone to hold the telephone number of clinics, by removing the tellNo column from the Clinic table along with a copy of the primary key of the Clinic table. The primary key for the new ClinicTelephone table is now the telNo column. The Clinic and ClinicTelephone table are in 1 NF as there is a single value at the intersection of every column with every record for each table Clinic (Not 1NF) clinicNo address telNo openingHour C001 Enfield 503-555-3618, 503-555-2727, 503-555-6534 9.00-21-00 C002 Islington 206-555-6756, 206-555-8836 9.00-21-00 C003 Hackney 212-371-3000 9.00-21-00 C004 Holloway 206-555-3131, 206-555-4112 9.00-21-00 C005 Chingford 8502333 9.00-21-00 C006 Leyton 4650000 9.00-21-00 Remove telNo column and create a new column called telNo in the new table Take copy of clinicNo column to new table to become foreign key ClinicTelephone (1NF) clinicNo telNo C001 503-555-3618 C001 503-555-2727 C001 503-555-6534 C002 206-555-6756 C002 206-555-8836 C003 212-371-3000 C004 206-555-3131 C004 206-555-4112 C005 8502333 C006 4650000 Clinic (1NF) clinicNo address openingHour C001 Enfield 9.00-21-00 C002 Islington 9.00-21-00 C003 Hackney 9.00-21-00 C004 Holloway 9.00-21-00 C005 Chingford 9.00-21-00 C006 Leyton 9.00-21-00 Second normal form (2NF) Second normal form applies only to tables with composite primary keys that are table with a primary key composed of two or more columns. A 1NF table with a single column primary key is automatically in at least 2NF. A table that is not in 2NF may suffer from update anomalies. A table that is already in 1NF and which the values in each non-primary-key column can be worked out from values in all columns that make up the primary key. Third normal form (3NF) Although 2NF table have less redundancy that table in 1 NF, they may still suffer from update anomalies. A table that is already in 1NF and 2NF, and in which the values in all non-primary key columns can be worked out from only the primary key column and no other columns. staffNo name lastName salary clinicNo clinicAddress telNo S001 Tom Adams 25000 C001 Enfield 5035553618 S002 Sally Daniels 35222 C001 Enfield 5035553618 S003 Mary Chin 5200 C002 Islington 206555675 S004 Sally Stern 5000 C002 Islington 206555 S005 Art Peters 45822 C003 Hackney 8502333 S006 Tommy Verciti 65000 C004 Holloway 4650000 Values in clinicNo and clinicAddress columns can be worked out from telNo, so table not in 3NF Values in clinicNo and telNo columns can be worked out from clinicAddress, so table not in 3NF Values in all non-primary-key columns can be worked out from the primary key, staffNo Values in clinicAddress and telNo columns can be worked out from clinicNo, so table not in 3NF staffNo name lastName salary clinicNo clinicAddress telNo StaffClinic (Not 3NF) staffNo name lastName salary clinicNo clinicAddress telNo S001 Tom Adams 25000 C001 Enfield 5035553618 S002 Sally Daniels 35222 C001 Enfield 5035553618 S003 Mary Chin 5200 C002 Islington 206555675 S004 Sally Stern 5000 C002 Islington 206555 S005 Art Peters 45822 C003 Hackney 8502333 S006 Tommy Verciti 65000 C004 Holloway 4650000 Move column to new table Take copy of clinicNo column to new table to become primary key Clinic (3NF) clinicNo clinicAddress telNo C001 Enfield 5035553618 C001 Enfield 5035553618 C002 Islington 206555675 C002 Islington 206555 C003 Hackney 8502333 C004 Holloway 4650000 Staff (3NF) staffNo name lastName salary clinicNo S001 Tom Adams 25000 C001 S002 Sally Daniels 35222 C001 S003 Mary Chin 5200 C002 S004 Sally Stern 5000 C002 S005 Art Peters 45822 C003 S006 Tommy Verciti 65000 C004 Primary key Becomes foreign key Becomes candidate key Becomes primary key Task 3 Using a Database Management System (DBMS) of your choice, set up all the above normalized tables, and populate them with well-designed test data (minimum 5 records per table). Provides printouts of all tables. Reasonable assumption may be made with regard to data Clinic Table create table clinic ( clinicNO int not null primary key, telNo varchar(255), address varchar(255), ) alter table clinic add clinicName varchar (255) alter table clinic add openingHour varchar(255) alter table clinic add eTelNo varchar (255) insert into clinic values (01,2863015,Darwin Avenue,8.00-21.00,2863000,Enfield) insert into clinic values (02,4650001,John David Avenue,8.00-21.00,2868000,Islington) insert into clinic values (03,4278926,King Arthur Avenue,8.00-21.00,2867000,Hackney) insert into clinic values (04,2682365,Paul Mac Avenue,8.00-21.00,2866000,Holloway) insert into clinic values (05,4682685,James Micheal Avenue,8.00-21.00,2865000,Chingford) insert into clinic values (06,2863015,Benaoit Frank Avenue,8.00-21.00,2864000,Leyton) Pet owner create table petowner ( ownerID int not null primary key, oFName varchar (255), oLName varchar (255), clinicNo int foreign key references clinic (clinicNo)) alter table petowner add addres varchar(255) alter table petowner add hTelNo varchar(255) alter table petowner add mTelNo varchar (255) insert into petowner values (01,Marvin,Hemraj,1,Edith Cavel Str,2106584,758956) insert into petowner values (02,Ramjeet,Lavin,2,Avenue Gonin,2564589,7585695) insert into petowner values (03,Arzeena,Bakarkhan,3,Gorgetown Str,2106584,758956) insert into petowner values (04,Chetan,Sing,4,Jackson Road,2458695,7582658) insert into petowner values (05,Hansley,Nowjee,5,15 Ollier Avenue,2565458,7589562) insert into petowner values (06,Sam,Fisher,6,Leess Street,26584585,75895623) Pet Table create table pet ( petNo int not null primary key, type varchar (255), breed varchar (255), sex varchar (255), dob varchar (255) ) alter table pet add clinicNo int foreign key references clinic (clinicNo) alter table pet add ownerid int foreign key references petOwner (ownerid) alter table pet add petName varchar (255) insert into pet values (01,Dog,Terroer,Male,1 Jan 2004,01,01,Wouf) insert into pet values (02,Dog,Poodle,Female,2 Feb 2005,02,02,Snoopy) insert into pet values (03,Cat,Persian,Male,3 March 2006,03,03,Minous) insert into pet values (04,Cat,Siamese,Female,4 April 2007,04,04,Milous) insert into pet values (05,Rabit,Dwarf,male,5 May 2008,05,05,Lapino) insert into pet values (06,Cat,Siamese,Female,4 June 2009,06,06,Lapinas) Examination Table create table examination ( examNo int not null primary key ) alter table examination add veterinaryId int foreign key references veterinary (veterinaryId) alter table examination add petNo int foreign key references pet (petNo) alter table examination add presDrugType varchar (255), presPeriod varchar (255) insert into examination values (1,1,Anti-biotic,15,01) insert into examination values (2,2,Painkiller,14,02) insert into examination values (3,3,Behaviour modification,13,03) insert into examination values (4,4,Ear medication,12,04) insert into examination values (5,5,Skin medication,15,05) insert into examination values (6,6,Painkiller,10,06) Appointment Table create table appointment ( appNo int not null primary key, aDate varchar (255), aTime varchar (255), petNo int foreign key references pet (petNo), ownerID int foreign key references petowner (ownerID), veterinaryId int foreign key references veterinary (veterinaryId) ) alter table appointment add clinicNO int foreign key references clinic (clinicNO) alter table appointment alter column aDate date insert into appointment values (01,2 October 2010,10.00,1,1,1,1) insert into appointment values (02,3 November 2009,10.35,2,2,2,2) insert into appointment values (03,4 December 2009,13.00,3,3,3,3) insert into appointment values (04,5 January 2010,15.00,4,4,4,4) insert into appointment values (05,6 Feb 2010,18.00,5,5,5,5) insert into appointment values (06,7 March 2010,9.00,6,6,6,6) Invoice Table create table invoice ( invoiceNo int not null primary key, ownerid int foreign key references petowner (ownerid), amt int ) alter table invoice add examNo int foreign key references examination (examNo) insert into invoice values (01,01,500,1) insert into invoice values (02,02,2000,2) insert into invoice values (03,03,400,3) insert into invoice values (04,04,300,4) insert into invoice values (05,05,1500,5) insert into invoice values (06,06,750,6) Veterinary Table create table veterinary ( veterinaryId int not null primary key, name varchar (255), Address varchar(255), hTelNo varchar(255), mTelNo varchar(255), clinicBranch varchar (255), specialise varchar(255) ) select * from veterinary alter table veterinary add spspecialise varchar(255) alter table veterinary drop column clinicBranch alter table veterinary add clinicNo int foreign key references clinic (clinicNo) insert into veterinary values (01,Jean,High Street Way 43,6358264,7595865,1,dog) insert into veterinary values (02,Robbin,Lower Downtown 2,6582354,7362548,2,cat) insert into veterinary values (03,Ricky,Market Ville Road,4582356,7586523,3,rabit) insert into veterinary values (04,Rowan,Little China Road2,4582653,7263158,4,dog) insert into veterinary values (05,Laksh,Havana Roadway,8596564,7236458,5,rabit) insert into veterinary values (06,Hans,Talipos Road,4625687,7859584,6,cat) Task 4 Set-up and test all of the following queries using Structured Query Language (SQL). Provide printouts of SQL code for each query and the output produced when you run the query in the database you have developed. Query Question 1 Display the names and address of the branches of Petcare and the name of all veterinary doctors working at each of the branches. Any specialism (s) of the veterinary doctors should also show. Using SQL Code SELECT clinic.clinicName AS [Branches Name], clinic.address AS [Branches Address], veterinary.name AS [Veterinary Doctor Name], veterinary.specialise AS [Veterinary Specialism] FROM clinic INNER JOIN veterinary ON clinic.clinicNO = veterinary.clinicNo The Result Using Query Designer The Result Query Question 2 Display all the appointments for the whole of the Petcare organization. This should be ordered by date. The result should display the branch the appointment is at, the name of the veterinary doctor the appointment is with, the date and time of the appointment, the name of the animal the appointment is for, the type of animal and the breed of the animal. Using SQL code SELECT clinic.clinicName AS [Branches Name], veterinary.name AS [Veterinary Doctor Name], appointment.aDate AS [Appointment Date], appointment.aTime AS [Appointment Time], pet.petName AS [Pet Name], pet.type AS [Pet Type], pet.breed AS [Pet Breed] FROM appointment INNER JOIN clinic ON appointment.clinicNO = clinic.clinicNO INNER JOIN veterinary ON appointment.veterinaryId = veterinary.veterinaryId AND clinic.clinicNO = veterinary.clinicNo INNER JOIN pet ON appointment.petNo = pet.petNo AND clinic.clinicNO = pet.clinicNo ORDER BY [Appointment Date] The Result Using Query Designer The Result Task 5 Explain any assumptions you have made when analyzing, designing and implementing the above database, justify the approach you have taken and explain any alternative approaches you could have taken to any of the above tasks. Discuss any changes you would make to improve your work. Determine candidate, primary and alternate key attributes This step is concerned with identifying the candidate key for an entity and then selecting one to be the primary key. In the process of identifying primary keys, note whether an entity is strong or weak. In trying to identify candidate keys, I observe that the clinic number for the Clinic entity, the veterinary number for the veterinary entity, the invoice number for the Invoice entity are unique for the entire practice. On the other hand, the owner number for the PetOwner entity, the pet number for the Pet entity, are only unique for a particular clinic. Its not uncommon for a company to give different offices a degree of local autonomy. However, in a centralized database system its sometimes more appropriate to have uniqueness throughout the company. In discussion with the PetCare management, its agreed that all numbers should be allocated across the entire practice, as opposed to each branches. If this had not been the decision, it would have been necessary to add the clinic number to those numbers only unique within each clinic to gain uniqueness across the practice. With this in mind, I have now identify the primary keys and foreign key. Check model for redundancy At this point, I have a logical data model for Petcare. However, the data model may contain some redundancy which should be removed. More speci ¬Ã‚ cally, I have to: (1) Re-examine one-to-one (1:1) relationships. (2) Remove redundant relationships. (3) One-to-one (1:1) relationships Redundant relationships There are a number of relationships between PetOwner, Pet, Clinic, and Appointment, and a closer examination is useful to identify any redundant relationships. First of all, note that the PetOwner/Pet entities have mandatory participation in the POAttends/PAttends/Owns relationships, and that a PetOwner may own many pets. Therefore, for any given Appointment we can identify the Owner through the POAttends relationship, but we cannot then identify the Pet through the Owns relationship. However, for any given Appointment, we can identify the Pet through the PAttends relationship and for any given Pet we can identify the PetOwner through the Owns relationship, which suggests that the POAttends relationship is redundant. In a similar way, through the PAttends relationship we can identify the Pet, and through the Registers relationship we can identify the Clinic involved in the Appointment, which suggests the Schedules relationship is also redundant. Note that the IsContactedBy relationship between Clinic and PetOwner also appears to be redundant. However, PetCare notes the details of pet owners when they first make contact and only obtains the details of pets at the first appointment, and so the IsContactedBy relationship is retained. Check business rules Business rules are the constraints that I have impose in order to protect the database from becoming inconsistent. Of the six types of business rules, four were identified in previous steps and documented in the above. I consider the remaining two here: referential integrity and other business rules. Referential integrity There are two issues to consider here: (1) Identify whether nulls are allowed for the foreign key. In general, if the participation of the child table in the relationship is mandatory, then the strategy is tha

david souter :: essays research papers

Birth, Residence, and Family Born September 17, 1939 in Melrose, Massachusetts, son of Joseph Alexander and Helen Adams Hackett Souter. Education Harvard College, A.B. 1961, Phi Beta Kappa, selected Rhodes Scholar; Magdalen College, Oxford, 1963, A.B. in Jurisprudence 1989, M.A. 1989; Harvard Law School, LL.B. 1966. Law Practice Associate, Orr and Reno, Concord, NH, 1966-1968. Government Service Assistant Attorney General of New Hampshire, 1968-1971; Deputy Attorney General of New Hampshire, 1971-1976; Attorney General of New Hampshire, 1976-1978. Judicial Offices Associate Justice, New Hampshire Superior Court, 1978-1983; Associate Justice, New Hampshire Supreme Court, 1983-1990; Judge, U.S. Court of Appeals for the First Circuit, 1990; Associate Justice, Supreme Court of the United States, 1990. Other Assignments Maine-New Hampshire Interstate Boundary Commission, 1971-1975; New Hampshire Police Standards and Training Council, 1976-1978; New Hampshire Governor's Commission on Crime and Delinquency, 1976-1978, 1979-1983; New Hampshire Judicial Council, 1976-1978. Civic Activities Trustee, Concord Hospital, Concord, New Hampshire, 1972-1985, President 1978-1984; Trustee, New Hampshire Historical Society, 1976-1985; Vice President, 1970-1985, Overseer, Dartmouth Medical School, 1981-1987. Affiliations with Professional Organizations and Academic Institutions Merrimack County Bar Association; New Hampshire Bar Association; American Bar Association; Honorary Fellow, American Bar Foundation; National Association of Attorneys General; Honorary Fellow, American College of Trial Lawyers; Honorary Master of the Bench, Gray's Inn, London; Honorary Fellow, Magdalen College, Oxford; Associate, Lowell House, Harvard College. David H. Souter was born in Melrose, Massachusetts, on September 17, 1939. He graduated from Harvard University in 1961. The following year he studied at Magdalen College in Oxford, England, as a Rhodes Scholar. He graduated from Harvard Law School in 1966. Souter was admitted to the bar and joined a law firm in Concord, New Hampshire. In 1968, he became an Assistant Attorney General of New Hampshire. In 1971, Souter became Deputy Attorney General and in 1976 Attorney General of the State of New Hampshire. During these years Souter also served on the New Hampshire Governor's Commission on Crime and Delinquency, the New Hampshire Judicial Council, the Maine-New Hampshire Interstate Boundary Commission, and the New Hampshire Policy Standards and Training Council.

Minor characters in “To Kill a Mockingbird” Essay

Harper Lee uses minor characters in a variety of different ways to help explore and expose some of the main concerns brought up in the book, ranging from strict town morals, justice, all the way to racism and death due to racism. I have chosen to outline some of the ways in which Harper Lee uses three minor characters, Mayella Ewell, Heck Tate and Dolfus Raymond, to help emphasise and explore some of the major concerns in the book. Mayella Ewell is the first minor character I shall discuss; a beacon of racial prejudice and the injustice of the courthouses. She is considered to be trash along with the rest of the Ewell’s; despite the fact that she is one of the few Ewell’s who can read and write. As well as being literate she tries her best to make that most of what she’s got, â€Å"the quote about the flowers she keeps†. Despite her decency compared to the others in her family Mayella still only cares for her own wellbeing. When she forces herself upon Tom Robinson, in a last ditch attempt to feel some affection from a man, she is soon to realise the error of her ways. As Atticus says, â€Å"She has committed no crime, she has merely broken a rigid and time honoured code of our society† by going after a black man she has broken ‘the rules’ of Maycomb and thus she tries to hide the truth by abusing Maycomb’s harsh structure of injustice and racism. She is white and Tom is black meaning the court case, as she well knows, can only have one outcome. She would rather sentence a man to death for something she had done to him, â€Å"She reached up and kissed me ‘side of th’ face. She said she never kissed a grown man before an’s she might as well kiss a nigger.† than tell the court and the towns folk that she had come onto a black man. Harper Lee uses Mayella and her made up story to show the racism of the  justice system, she shows that simply by lying and having someone to lie with you when the case is white words against black the white will win. Despite Mayella’s story falling apart under cross-examination Tom’s version of what happened isn’t taken note of, as he is black. Also in this case, we have the testimonial of the local sheriff Heck Tate; he too is a tool of great injustice for the blacks. In his testimony we read that he was called by Bob Ewell and told that â€Å"some nigger’d raped his girl† upon arrival he found Mayella and asked who had done it – Tom Robinson. A black man accused by a white woman, Heck went and rounded him up instantly to be identified by Mayella. No questioning, no looking for evidence or any kind of service a white man could expect, Heck presumes that he is black and therefore must have committed some kind of crime. However, despite Heck’s injustice towards the black population of Maycomb he does fulfil his duties to the white. After Boo stabs Bob to save Atticus’ children Heck decides that for the greater good nothing should be said and the incident should be considered an accidental suicide. Heck shields the town from the truth and allows Boo to go back to his normal life – after all he had done the town a favour. Another man who shields the town from the truth, but about a very different subject is Dolphus Raymond, a presumed evil alcoholic who spends most of his time with the black townsfolk. â€Å"Come round here, son, I got something that’ll settle your stomach.† Is the invitation given by Dolphus to Dill outside the courthouse. He offers Dill his brown paper bag with straws in and tells the boy to take a good sip. Scout says † Dill, you watch out, now† as she, like the rest of the town believes that Dolphus is always sipping from a bottle of gin within his bag. He pretends to be drinking all day as â€Å"it’s mighty helpful to folks.† He is forced to pretend to be drinking all day and to be messed up in the head to help the prejudice people of Maycomb understand why he would want to spend most of his time with the black people. Only the uncorrupted children are trusted with Mr. Raymond’s deepest secret as he feels that because they  are children they can understand why he pretends to drink and why he has to give the people a reason as to why he spends his time with black people. This helps give an idea of the intolerance in the town. Intolerance towards black people and towards anyone who has contact with black people as a friend, rather than just a slave. Harper Lee uses minor characters traits and beliefs to show the reader some of the issues at hand in the book. Whether it be a girl pretending to have been raped to highlight the levels of injustice and the racial prejudice in the book, or whether its Heck Tait acting under the powerful words of a white person to do wrong to blacks, or his truth shielding to help a white man stay out of prison for a crime he really did commit.