Ex. VII. Express your own views on education. Discuss in pairs:
People go to university for different reasons (for example, new experiences, career preparation, increased knowledge). Why do you think people attend university? The following expressions can be useful for you:
| Im a student of University | ... . |
| Im in the physics department. | . |
| In which division are you? | ? |
| What will your major be? | ? |
| Im majoring in | ... |
| What year are you? | ? |
| Im a [number] year student. | (, -)... . |
| I live in the dorm | . |
| courses of study | |
| humanities |
Ex. VIII. A topic for writing:
Your country is going to build a new national university. What academic area should be the main focus of this university? Use specific reasons and examples to support your answer.
Audition: Smart House
Ex. I. Answer the following questions:
1. Do you like reading science fiction?
2. Have you got a computer at home and what do you use it for?
3. What kind of electrical household goods do you have at home?
Ex. II. Look up the following words in your dictionary and find the translation:
appliances (n)
blinds (n)
expenditure (n)
hand-held remote (n)
utilities (n)
key-pad (n)
humidity (n)
airflow (n)
carbon dioxide (n)
consumption (n)
luxury (n)
environment (n)
Ex. III. Fill in the gaps with the following words:
comfort, tank, expenditure, sensors, controller, presence, solar, meters, consumption, rainwater, automation, temperature
1. Smart houses with home systems have progressed from home to reality.
2. The goal of a smart house is to coordinate all domestic systems to minimize the of energy and maximize the of its occupants.
3. It is filled with dozens of hidden monitoring , humidity, airflow, carbon dioxide, and even human in the house.
4. On the roof of a smart house, a tunnel-like structure collects , which is sent to a holding
5. A boiler heats washing and bath water in the smart house.
6. Gas, electricity, and water are integrated with the so that utilities and homeowners can monitor
Ex. IV. Listen and check.
Ex. V. Listen again and answer the following questions:
1. Do smart houses exist today?
2. What do computers and sensors enable the smart house to do?
3. How do we interact with the home automation system?
4. What can you do if you want your smart house warm and cozy when you return home?
5. What can the computer do if the homeowner selects the going out mode on the master panel?
6. What can the computer do when the master panel is set to the party mode?
7. Is smart house technology just a luxury for the wealthy?
Unit VII
Part I
Ex. I. List and define the four database models.
Ex. II. Read the following text:
|
|
|
Database Models
Hierarchical Model
There are four types of database models: hierarchical, network, relational, and object-oriented.
In a hierarchical database, data relationships follow hierarchies, or trees, which reflect either a one-to-one relationship or a one-to-many relationship among record types (See Fig. 6). The uppermost record in a tree structure is called the root record. From there, data are organized into groups containing parent records and child records. One parent record can have many child records (called siblings), but each child record can have only one parent record. Parent records are higher in the data structure than are child records; however, each child can become a parent and have its own child records.
Fig. 6. Hierarchical data relationships.
Network Model
A network database is similar to a hierarchical database except that each record can have more than one parent, thus creating a many-to-many relationship among the records (See Fig. 7). For example, a customer may be called on by more than one salesperson in the same company, and a single salesperson may call on more than one customer. Within this structure, any record can be related to any other data element.
Fig. 7. Network data relationships.
The main advantage of a network database is its ability to handle relationships among various records. Therefore, more than one path can lead to a desired data level. The network database structure is more versatile and flexible than is the hierarchical structure because the route to data is not necessarily downward; it can be in any direction.
In both the network structure and the hierarchical structure, data access is fast because the data path is predefined. However, any relationship between data items must be defined when the database is being created. If a user wants to retrieve or manipulate data in a manner not defined when the database was originally created, it is costly and time-consuming to redesign the database structure. This limitation led to the development of the relational database model.
Relational Model
A relational database is composed of many tables in which data are stored, but a relational database involves more that just the use of tables. Tables in a relational database must have unique rows, and the cells (the intersection of a row and column equivalent to a field) must be single-valued (that is, each call must contain only one item of information, such as a name, address, or identification number). A relation database management system (RDBSM) allows data to be readily created, maintained, manipulated, and retrieved from a relational database.
In a relational database, data relationships do not have to be predefined. Users query a relational database and establish data relationships spontaneously by joining common fields. A database query language acts as an interface between users and a relational database management system. The language helps the users of a relational database to easily manipulate, analyse, and create reports from the data contained in the database.
Two basic query styles are used in a relational database: query by example, and structured query language. In query by example, the database management system displays field information and users enter inquiry conditions in the desired fields.
|
|
|
Object-Oriented Model
Although the relational model is well suited to the needs of storing and manipulating business data, it is not appropriate for the data needs of certain complex applications, such as computer-aided design (CAD) and computer-assisted software engineering (CASE). Business data follow a defined data structure that the relational models handle well. However, applications such as CAD and CASE deal with a variety of complex data types that cannot be easily expressed by relational models.
An object-oriented database uses objects and messages to accommodate new types of data and provides for advanced data handling. An object-oriented database management system (OODBMS) permits objects to be readily created, maintained, manipulated, and retrieved from an object-oriented database.
An OODBMS provides features that you would expect in any other database management system, but there is still no clear standard for the object-oriented model. OODBMSs are expected to evolve and be used for applications with complex data needs. They are not, however, expected to replace relational databases. Instead, they work in tandem, each suited for different tasks.
Active Words and Phrases:
| hierarchical | flexible | ||
| network | () | cell | |
| relational | intersection | ||
| object-oriented | ᒺ- | predefined | |
| relationship | query language | ||
| root record | query by example | ||
| parent record | inquiry | ||
| sibling | computer-aided design (CAD) | ||
| versatile | computer-assistant software engineering (CASE) |
Ex. III. Can you define the following terms?
database OODBMS
database management system query by example
database query language relation database
hierarchical database root record
object-oriented database structured query language
Ex. IV. Multiple choice:
1. The database model that allows each record to have more than one parent, creating a many-to-many relationship among the records is called a ________.
a) network database; b) hierarchical database;
c) object-oriented database; d) relational database.
2. A ________ database allows users to query a database using a database query language.
a) object-oriented; b) network;
c) hierarchical; d) relational.
3. A ________ allows part of a database located at a host computer to be duplicated and placed in a remote computer.
a) relational database; b) object oriented database;
c) hierarchical database; d) distributed database.
4. A ________ is the software that managers the creation, storage, access, updating, deletion, and use of a database.
a) file management system; b) database management system;
c) flat file; d) application.
