Entity-Relationship (E/R) Model Dr P Sreenivasa Kumar Professor CS&E Dept I I T Madras Entity-Relationship (E/R) Model Widely used conceptual level data model • proposed by Peter P Chen in 1970s Data model to describe the database system at the requirements collection stage • high level description. • easy to understand for the enterprise managers. • rigorous enough to be used for system building. Concepts available in the model • entities and attributes of entities. • relationships between
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Frank and Alex in a tug-of-war • Draw the free body diagram on the back of your sheet or your notes for Frank winning (accelerating away) a tugof-war with Alex – Draw Frank and Alex as separate objects‚ with forces acting on each – How many forces are there on each? – Identify Newton’s 3rd law pairs – Identify Newton’s 2nd law relationships 1 Frank and Alex in a tug-of-war • Draw the free body diagram on the back of your sheet or your notes for Frank winning (accelerating away)
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Why Wages Rise F. A. HARPER THE FOUNDATION FOR ECONOMIC EDUCATION‚ INC. IRVINGTON-ON-HUDSON‚ N E W YORK 1957 Copyright 1957 by F. A. HARPER Permission to reproduce from this book‚ without special request‚ is hereby granted by both the author and publisher. Information about uses will be appreciated. Library of Congress Catalogue Card No.: 57-6929. PRINTED IN U.S.A. Contents Page INTRODUCTION 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. LABOR UNIONS PRODUCTIVITY DIVIDING T H E P I E TOOLS
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Figure 1.0: Entity Relationship Diagram of Generic Academic Performance Monitoring System Figure 2.0: Context Diagram of Generic Academic Performance Monitoring System The figure 2.0 represents the two (2) users of the Generic Academic Performance Monitoring System namely the Administrator and the Professor. The Administrator entity shows the capability to access the system; manage account by modifying account’s profile; managing member’s account such as creating new user profile and updating
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1. How do social beliefs differ with age? Older adults have different social beliefs compared to other age groups. As adults age‚ they see the world differently and hold different beliefs than they were younger. Cavanaugh and Blanchard-Fields (2015) explain that the strength of older adults beliefs can differ as a result from how certain generations socialize (p. 223). Social cognitive researchers believe there are “differences in the strength of social representations of rules‚ beliefs‚ and attitudes
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thesis. Title page contains short‚ descriptive title of the proposed thesis project (should be fairly self-explanatory) and author‚ institution‚ department‚ research mentor‚ mentor’s institution‚ and date of delivery Abstract the abstract is a brief summary of your thesis proposal its length should not exceed ~200 words present a brief introduction to the issue make the key statement of your thesis give a summary of how you want to address the issue include a possible implication of your work
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Food Web Diagram Sci/230 November‚ 2013 Desert Biome Food Web Diagram Food Web Diagram An ecosystem can be defined as a more or less self-contained function unit in ecology consisting of all abiotic and biotic
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POTENTIAL ENERGY DIAGRAM In physics the terms of mechanical energy usually refers to Potential energy (U) and Kinetic Energy (K). In the absence of non-conservative‚ or dissipative forces‚ these energies obey the law of conservation of energy‚ or ΔU + ΔK = 0. That is‚ when a system is only acting under the influence of conservative forces its total energy content never changes‚ the energy just converts between forms. At any point in the cycle‚ the total energy is constant‚ U + K = Umax = Kmax
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endothermic process. In the graph‚ each substance has a different curve. Some lowered the temperature much more than others. This is because different substances require differing amounts of energy to evaporate. To test this‚ the temperature change from the evaporation of 4 different alcohols was measured and compared‚ along with cyclohexane. Methanol had the largest change in temperature‚ 18.9 ºC. This indicates that methanol has the weakest intermolecular attractions out of the 4 alcohols‚ because
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USE-CASE DIAGRAM EXERCISE 1. Draw a use case diagram for an ATM machine with the following functionality. A customer’s interaction with the system involves logging in‚ making withdrawal requests‚ deposit requests‚ and balance inquiry requests. If the customer logs in‚ there is a possibility (although rare) that the system will confiscate the card (for example‚ if the login is incorrect or if the bank determines that the customer’s balance is significantly under zero). Card confiscation involves
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