Notes, summaries, assignments, exams, and problems for Computers

Topic 2: Information Technology Fundamentals

IT Vocabulary Exercises

Word Matching: Find the Synonyms/Related Terms

• Click
• Sharp
• Back up
• Range
• Displays

Software Terminology Matching

• 1. C
• 2. F
• 3. G
• 4. H
• 5. B
• 6. D
• 7. I
• 8. E
• 9. A

Listening Comprehension: True or False

• (1, 4, 5, 8) = False
• (2, 3, 6, 7) = True

Classifying Phrases for IT Descriptions

• Consist of
• Can be divided into
• Includes
• Is a type of
• There are two classes

Workbook Activities: Computer Components

1. Hardware Parts Identification

• Flat LCD monitor
• Mouse
• DVD Drive
• Printer
• Webcam

2. IT Crossword Puzzle Answers

• 1. Input
• 2. Port
• 3. Keyboard
• 4. CPU
• 5. Peripherals
• 6. Software
• 7. Output
• 8. Drive
• 9. Hardware

3. Computer Device Types (Email Context)

• Laptop
• PDA
• Mainframe
• Tablet PC
• Desktop PC

4. Prepositions for Classification

• Classify into
• Divide

Java Socket Implementation

Client-Server Socket Class (`Misocket`)

Constructor for Server (`Misocket(int port)`):

• Initializes a `ServerSocket` with the specified port.
• Waits for and accepts a client connection using `serverSocket.accept()`.
• Obtains input and output streams from the accepted client socket.

Constructor for Client (`Misocket(String ip, int port)`):

• Creates a `Socket` to connect to the specified IP address and port.
• Obtains input and output streams for communication.

Core Functionality

Sending and Receiving Strings:

• `dos.writeUTF(cadena); dos.flush();` to send a string.
• `cadena = dis.readUTF(); return cadena;` to receive a string.

Sending and Receiving Integers:

• `dos.writeInt(tam);` to send an integer.
• `tam = dis.readInt(); return tam;` to receive

Understanding Pointers in Programming

A pointer is a variable whose value is the memory address of another variable. Like any variable or constant, you must declare a pointer before you can work with it.

C++ Pointer Example

#include <iostream>
using namespace std;

int main ()
{
    int var = 20; // Actual variable declaration.
    int *ip;      // Pointer variable declaration.

    ip = &var;    // Store address of var in pointer variable.

    cout << "Value of var variable: " << var << endl;

    // Print the address stored in ip pointer variable
    cout << "Address stored in ip variable: " << ip << endl;

    // Access the value at the address available in pointer
    cout << "Value of *

Four Servers Reside in the DMZ

• Mail
• WWW
• DNS
• Log Servers

DMZ Mail Server (a Separate Machine)

When an Email Message is Received from the Internet:

1. Reassembles the message.
2. Checks for malicious content.
3. Changes the addresses of the outer firewall (which is how the mail server is known to the outside world) to that of the internal mail server and forwards the mail to the internal mail server.

To Send a Message from the Internal Network to the Internet:

1. Reassembles the message.
2. Checks for malicious content (and maybe for proprietary information).
3. All internal addresses are replaced with "drib.org" (the name of the outside firewall).

DMZ WWW Server (a Separate Machine)

• Does not contact any servers or information sources on the internal network and it contains

Operating System Scheduling

1. The OS enables running multiple programs simultaneously. Several programs can reside in RAM concurrently, yet the CPU processes only one at a time. Only one process can be active at any given moment. CPUs are incredibly fast; even brief processing periods yield significant results. The OS determines the optimal method for switching between running, runnable, and waiting processes. It manages which process the CPU executes and distributes CPU access among processes. The task of determining when to switch processes is termed scheduling.

Disk Defragmentation

2. A disk defragmenter reorganizes files on a disk, ensuring they are stored contiguously. It arranges files on the disk into adjacent locations. This enhances... Continue reading "Understanding Operating Systems, Software, and Computer Hardware" »

Printer Types: A Comparative Analysis

Understanding the differences between various printer types is crucial for making informed decisions. Here's a comparison of common printer technologies:

• Laser Printers: Generally faster than plotters.
• Color Laser Printers: Offer significant advantages over standard monochrome laser printers, especially for vibrant outputs.
• Inkjet Printers: Typically slower than laser printers but often excel in photo quality.
• Dot Matrix Printers: Surprisingly, these can be more expensive than plotters, especially for specialized industrial models.
• Sublimation Printers: Often considered to have lower print quality compared to inkjet printers for general use, but excel in specific applications like photo printing or fabric.
• Plotters:

Database Design Fundamentals

Key Concepts and Definitions

Data Type

The data type determines what field values are allowed and what other properties the field will have.

Saving a Table

You can specify a name for a table after you click the Save button on the Table Design toolbar.

Table Structure

The final step in the creation of a table is to save the table structure to disk.

Primary Key

A primary key uniquely identifies each record in a table.

Identifying Fields

When designing a database, you need to identify the fields that will be required.

Data Redundancy

Storing the same data field in multiple tables is called data redundancy.

Composite Key

A primary key that consists of more than one field is called a composite key.

Avoiding Data Redundancy

When designing... Continue reading "Database Design: Mastering Data Types, Keys, and Queries" »

Design patterns offer proven solutions to recurring software design challenges, promoting code reusability, maintainability, and efficiency. They can be categorized into three main types:

Behavioral Design Patterns

These patterns focus on communication and interaction between objects, enhancing flexibility. Examples include:

• Observer Pattern: Enables one-to-many dependencies, where changes in one object automatically notify dependent objects.
• Iterator Pattern: Provides sequential access to elements within a collection without exposing its underlying structure.

Creational Design Patterns

These patterns address object creation mechanisms, ensuring suitable instantiation processes. Examples include:

• Singleton Pattern: Restricts object creation to a single

Understanding Deadlock

A deadlock is a critical situation in which two or more computer programs, sharing the same resource, effectively prevent each other from accessing that resource. This results in both programs ceasing to function or becoming unresponsive.

Historically, the earliest computer operating systems ran only one program at a time, making all system resources available to that single program. As operating systems evolved to run multiple programs concurrently through interleaving, programs initially had to specify their resource needs in advance to avoid conflicts.

The advent of dynamic resource allocation, where programs could request further resources after execution began, introduced the problem of deadlocks. Addressing deadlocks... Continue reading "Deadlock and Semaphores: Concurrency in Operating Systems" »