Relational Schema Design for University and Hospital Systems
ER Diagram Conversion to Relational Schema
The objective is to convert specified Entity-Relationship (ER) diagrams into a functional relational schema, defining appropriate primary and foreign keys.
A. University Database Relational Schema Mapping
Assuming the ER diagram for the University includes the following entities and relationships (based on typical university data models):
Entities Defined:
- Student: (sid, sname, age, major)
- Course: (cid, cname, credits)
- Professor: (pid, pname, department)
- Department:
Neural Communication: Synaptic Transmission and cAMP Signaling
Synaptic Transmission: The Release Mechanism
The action potential signal arrives at the axon terminal (the bouton). The local depolarization causes voltage-gated Ca²⁺ channels to open. Calcium (Ca²⁺) enters the presynaptic cell because its concentration is greater outside the cell than inside.
The influx of Ca²⁺ triggers the release of neurotransmitters through the following steps:
- Ca²⁺ binds with calmodulin, causing vesicles filled with neurotransmitter to migrate toward the presynaptic
Sericulture and Silkworm Rearing: Production and Biology
Sericulture: Definition and Economic Importance
Sericulture is the rearing of silkworms for the production of silk. It is a farm-based, labor-intensive, and commercially profitable agro-industry that provides employment and income to rural people, especially women and small farmers.
Main Scopes and Benefits of Sericulture
- Employment Generation: Provides year-round jobs to farmers, reelers, weavers, and traders.
- Rural Development: Boosts the rural economy through cottage industries.
- Export Potential:
Transaction Cost Economics and Risk Management Principles
Transaction Cost Economics (TCE)
Transaction Cost Economics (Williamson) is a branch of economics that studies the solution to coordination and motivation problems using price and non-price mechanisms.
Core Principles of Williamson’s TCE
- i) It makes the transaction the basic unit of analysis.
- ii) Transactions differ in attributes that are relevant for the decision on how to govern them.
- iii) Contracts govern transactions, and the list of available contracts is much larger than the narrow view of pure
Gender Roles and Literary Symbolism in Short Fiction
Part 2: Gender and Symbolism
Both “The Yellow Wallpaper” by Charlotte Perkins Gilman and “Cat Person” by Kristen Roupenian explore how gender roles limit women’s freedom and self-expression. In both stories, symbolism helps the reader understand the emotional and social struggles women face.
In “The Yellow Wallpaper,” the narrator is a woman suffering from depression whose husband controls every part of her life. He decides what she does, what she reads, and even what she thinks. The
Read MoreCell Biology: Theory, Transport, and Structures
Cell Theory and Microscope Technology
1. Can cells appear spontaneously without genetic material from a previous cell?
No, cells do not appear spontaneously; they pass copies of their genetic material on to their daughter cells.
2. Compare and contrast a TEM and SEM.
In a TEM (Transmission Electron Microscope), electrons are transmitted through a specimen to a fluorescent screen. An SEM (Scanning Electron Microscope) is a modification that directs electrons over the surface of the specimen, producing
Read Moretgervfrs
6 STRATEGIC BUSINESS OBJETIVES for implementation are:
1. Operational excellence: improve efficiency, productivity and performance through automation and streamlined process. Walmart uses real-time inventory systems to reduce costs.
2. New products, services and business models: enable innovation and create new ways of delivering value. Apple → iTunes / Appstore innovation.
3. Customer and supplier intimacy: use systems to build stronger relationships, improve service and increase loyalty. Amazon
Operating System Concepts: Processes, Threads, and Scheduling
CH 3 – Processes
Definition:
Process = program in execution (active); program = passive file.
Process layout:
Text (code) | Data (globals) | Heap (dynamic alloc.) | Stack (function frames).
States:
new → ready → running → waiting → terminated.
PCB (Process Control Block):
state, PC, registers, priority, memory info, I/O status, accounting.
Schedulers:
Long-term (job) → admit to memory (degree of multiprogramming); Short-term (CPU) → choose next ready process; Medium-term → swap in/out
Workshop
We say that there is a surge when the nominal voltage of 220VAC, a certain percentage goes up and stays there for a certain period of time say that there are tensions Low Low voltage when the nominal value of 220 VAC, low a percentage and maintained at that value over a period of time peaks, transients and electrical noise or transient spikes appear in the power line for example when switched on or off electric motors. It appears as a very sudden surge of very high value during a tiny period of
Read MoreEssential English Grammar: Verbs, Modals, and Structures
The Verb “To Be” in the Past Simple: Was / Were
Affirmative and Negative Forms
| Subject | Affirmative | Negative |
|---|---|---|
| I | was | wasn’t |
| You | were | weren’t |
| He/She/It | was | wasn’t |
| We/You/They | were | weren’t |
Questions
Structure: Was/Were + Subject
- Was I?
- Were You?
- Was He/She/It?
- Were We/You/They?
Existential Sentences: There Was / There Were
| Form | Singular Example | Plural Example |
|---|---|---|
| Affirmative | There was a concert. | There were ten people. |
| Negative | There wasn’t a concert. | There weren’t any people. |
The Imperative Form
Affirmative Commands
- Make a fire!
- Help me!