TRUNG TÂM ĐÀO TẠO BIM XÂY DỰNG
Phòng G01 - H1, Hẻm 1034, đường Nguyễn Ái Quốc, Tổ 13, KP1, P. Trảng Dài TP.Biên Hòa, Tỉnh Đồng Nai
Email: bimxaydung@gmail.com
Website: http://bimxaydung.com
FB: https://www.facebook.com/bimxaydung
TRUNG TÂM ĐÀO TẠO BIM XÂY DỰNG
Phòng G01 - H1, Hẻm 1034, đường Nguyễn Ái Quốc, Tổ 13, KP1, P. Trảng Dài TP.Biên Hòa, Tỉnh Đồng Nai
Email: bimxaydung@gmail.com
Website: http://bimxaydung.com
FB: https://www.facebook.com/bimxaydung
Giao Trinh Cong Nghe Can Va Thiet Ke Lo Hinh Truc Can 1 Nhieu Tac Gia 229 TrangHọc Cơ Khí
Giao Trinh Cong Nghe Can Va Thiet Ke Lo Hinh Truc Can 1 Nhieu Tac Gia 229 Trang, Giao Trinh Cong Nghe Can Va Thiet Ke Lo Hinh Truc Can 1 Nhieu Tac Gia 229 Trang, Giao Trinh Cong Nghe Can Va Thiet Ke Lo Hinh Truc Can 1 Nhieu Tac Gia 229 Trang, Giao Trinh Cong Nghe Can Va Thiet Ke Lo Hinh Truc Can 1 Nhieu Tac Gia 229 Trang
This document outlines requirements and activities for modeling a CD database using an entity-relationship diagram and relational database. It describes 9 requirements for the CD archive, including information on CDs, songs, artists, records, and contact information. Students are asked to:
1) Create an ER diagram modeling the CD archive requirements and translate it to a relational database using SQL.
2) Model ER diagrams for a car insurance company and hospital database.
3) Consider an alternative ER diagram for a university exam scheduling database using additional entity sets for courses, sections, rooms instead of single exam entity set.
This document provides an overview of SQL and database concepts. It discusses:
- The basic structure of tables, rows, columns, and data types
- The four main SQL languages: DDL, DML, TCL, and DCL and common commands like CREATE, INSERT, UPDATE, DELETE, etc.
- Database objects like tables, views, indexes, and how to query them
- Constraints like PRIMARY KEY, UNIQUE, NOT NULL and REFERENTIAL integrity
- Transactions with COMMIT, ROLLBACK, and SAVEPOINT
The document contains a quiz about database normalization with 7 multiple choice questions. Second normal form decomposes tables in first normal form into two or more tables. A foreign key is a field that matches a key field in another table. The relational database model was proposed in the 1970s. Normalization is the process of decomposing a table into more tables to fit the relational model. Third normal form ensures there are no transitive dependencies between non-key fields. A one to many relationship allows each record in one table to have multiple matching records in another table.
This document provides an introduction to database management systems (DBMS). It discusses the disadvantages of traditional file-based data management approaches, such as data redundancy and lack of data integrity. It then describes the key components of a database system, including the database itself, DBMS software, users, and administrators. Challenges of DBMS include security, data quality, and data integrity issues that must be addressed. The overall system structure partitions responsibilities between query processing and storage management components.
The document contains a quiz about entity relationship models with 7 multiple choice questions. An entity is defined as a real or conceptual "thing" in the database. A many-to-many relationship is represented by a double line symbol. The graphic shows the relationship that a student can own 0, 1 or more cars. An ER model provides a logical view of the data structure and relationships without details of physical implementation.
Transactions allow concurrent execution of user programs while maintaining data consistency. The DBMS abstracts user programs as transactions consisting of reads and writes. Through concurrency control techniques like locking and logging of writes, the DBMS ensures transactions execute reliably and leave the database in a consistent state, even if transactions interleave or the system crashes. The ACID properties guarantee atomicity, consistency, isolation, and durability for all transactions.
The document discusses normalization, which is the process of organizing data to avoid anomalies. It covers first normal form (1NF), second normal form (2NF), and third normal form (3NF). 1NF means eliminating repeating groups and multi-valued attributes. 2NF means the relation depends on only the primary key. 3NF means removing transitive dependencies between non-key attributes. Various examples show how to decompose relations into multiple tables in higher normal forms to eliminate anomalies like insertion, deletion, and modification issues.
The document discusses relational database concepts including:
- Relations are represented by tuples with attribute names in parentheses
- Primary keys uniquely identify rows and can be single or composite attributes
- Foreign keys link tables and reference a primary key in another table
- Tables must have a primary key and relations cannot contain multivalued attributes
The document describes specifications for an entity-relationship (E-R) schema for an educational institute. It includes entities for departments, professors, students, courses, sections (specific course offerings), and projects. Relationships include students enrolled in sections, professors teaching sections and working on projects, and departments offering courses. The E-R diagram shows the relationships between these entities.
This document discusses the selection of a transformer for an industrial plant that produces compressed gas and packaging. It analyzes two options:
1) Using one 250KVA transformer with a voltage rating of 22/0.4KV. This has lower investment costs but does not ensure continuous power supply if it fails.
2) Using two 100KVA transformers with a voltage rating of 22/0.4KV. This ensures continuous power supply even if one transformer fails, as the remaining transformer can handle the full load. This option is selected for the plant due to its lower total investment costs.
Accessories like lightning arresters, fuse cutouts, and a backup diesel generator are also selected to ensure reliable power supply.
07 2 chapter7-cross-section diagrams in 3 dimentions part 2-2khoahuy82
Fence diagrams and block diagrams are commonly used to illustrate three-dimensional geological relationships. Fence diagrams consist of a network of geological cross sections drawn in two dimensions on a map base seen in plan view. Block diagrams represent a rectangular block, with two intersecting cross sections forming the sides and the top showing a mapped surface. Both diagrams can be constructed with or without perspective to best display important geological features.
1. Petroleum geology involves the study of the origin, properties, and occurrence of hydrocarbon resources. It draws upon principles of chemistry, physics, and biology.
2. The key requirements for petroleum accumulation are a mature organic-rich source rock, migration pathways, a porous reservoir rock, an impermeable caprock seal, and a structural or stratigraphic trap.
3. Crude oil is a complex mixture of hydrocarbons that exists in the liquid phase in natural underground reservoirs. Its physical and chemical properties vary between different oil deposits.
