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

Fundamental Number Concepts

Prime Numbers Up to 97

Here is a list of prime numbers up to 97:

• 2
• 3
• 5
• 7
• 11
• 13
• 17
• 19
• 23
• 29
• 31
• 37
• 41
• 43
• 47
• 53
• 59
• 61
• 67
• 71
• 73
• 79
• 83
• 89
• 97

Rules for Exponents

Understanding how exponents work is crucial for various mathematical operations:

• Positive Base: If the base (m) is positive, the result (b) of mn = b is always positive.
• Negative Base, Even Exponent: If the base (-M) is negative and the exponent (n) is an even number, the result (+b) of (-M)n = +b is positive.
• Negative Base, Odd Exponent: If the base (-M) is negative and the exponent (n) is an odd number, the result (-b) of (-M)n = -b is negative.

Powers of Decimal Numbers

Here are examples of squaring and cubing decimal numbers:

• 1.12 = 1.21
• 0.42 = 0.16
• 0.032 = 0.0009
• 0.23 = 0.008

Divisibility Criteria

Divisibility... Continue reading "Essential Number Properties and Divisibility Rules" »

Programming Language Fundamentals

Level Classification

• Low Level: Resembles the language used by the computer directly.
• High Level: Resembles human language, abstracting machine details.

Generations of Programming Languages

• 1st Generation (1GL): Machine Language
• 2nd Generation (2GL): Assembler
• 3rd Generation (3GL): High-level languages (e.g., Fortran, Pascal, C, C++, Cobol)
• 4th Generation (4GL): Languages for specific purposes (e.g., web development, PHP, Java, HTML)

Key Programming Concepts

Program

A set of instructions or orders based on a programming language that a computer interprets to solve a problem or perform a specific function.

Programming Language

Tools that allow us to create programs and software. An artificial language used to define a sequence... Continue reading "Programming Language Basics & Database Models" »

Semaphores: Synchronization Tool

Semaphores are a synchronization tool designed to solve critical section and synchronization problems. A semaphore is an integer variable accessed only through two atomic operations: Wait and Signal. When a process modifies the semaphore's value, no other process can simultaneously modify that same semaphore value. The semaphore is initialized to a non-negative value.

Wait and Signal Operations

• Wait (P): Decrements the semaphore's value. If the value becomes negative, the process is blocked.
• Signal (V): Increments the semaphore's value. If the value is not positive, a blocked process waiting on this semaphore is unblocked.

The definitions are:

P(s):

while (s <= 0)
s--;

V(s):

s++;

Operating System Usage

Operating... Continue reading "Semaphores for Synchronization in Operating Systems" »

Secure Sockets Layer (SSL)

Secure Sockets Layer (SSL) is most often used to encrypt information on the Internet. It is a protocol that encrypts database (DB) connections by selecting an encryption method and generating the necessary keys for the entire session.

How SSL Works

1. The browser requests a page from a secure server. The request is identified by the HTTPS protocol.
2. They agree on algorithms that ensure confidentiality, integrity, and authenticity.
3. The server sends the browser its standard X509 certificate containing its public key. If the application requires it, it in turn requests the client's certificate.
4. The browser sends the server a master key from which it generates the session key to encrypt data to be exchanged.
5. Finally, it checks the

Models of Network Integration

Typically, a network encompasses a wide range of technologies. Not all technologies meet all the needs of the network administrator. A network of a certain size is usually a mixed-technology network due to the various factors involved.

Key Aspects of Network Integration:

• Wiring System Response: The wired network forms the backbone of any Local Area Network (LAN). Typically, all servers have at least one connection to the wiring harness, and if they handle substantial traffic, the connection is high-speed. Clients can connect to services through a structured cabling network or wireless connections. Note that the bandwidth of a wireless access point is generally less than that of wired Ethernet access and is shared

Workshop Planning and Control

Planning

Planning aims to coordinate workload with available resources and equipment to perform the required services in production, or the quantity and quality required, at the lowest cost and meeting the deadline.

Organization

Methods, order, time > budget OR > acceptance > delivery term.

Workload

The workload is the amount of work available for the workshop, consisting of the OR already issued and accepted by clients.

Production Capacity

Production capacity is the amount of work that the workshop can perform based on available operators, equipment, and facilities.

The workload can be defined in a working or time to implement and scale, or are uncertain about working with an open OR work involving a diagnostic... Continue reading "Workshop Workload and Production Capacity Management" »

Memory Management Definition

Memory management is the process of:

• Bringing programs into the main memory to be executed by the processor.
• Dynamically dividing the part of main memory to accommodate multiple processes.
• Allocating memory efficiently for packaging processes, preventing the processor from being idle.
• Enabling the execution of a larger program than is available in real memory.

Memory Management Requirements

1. Relocation

• Ability to move a program from one region to another of the main memory without invalidating the memory references.
• The processor hardware and operating system translate the memory references' addresses to the final physical memory addresses.

2. Protection

Each process must be protected from unwanted interference from other... Continue reading "Memory Management Concepts and Techniques" »

Fuzzy Logic

Fuzzy logic extends Boolean logic, allowing intermediate values between TRUE (1) and FALSE (0), such as MAYBE (0.5). A fuzzy logic value can be any value within the range of 0 to 1. This logic incorporates statistical concepts, especially in inference. Fuzzy logic implementations enable control devices to handle indeterminate states, allowing for the evaluation of non-quantifiable concepts. Practical examples include evaluating temperature (hot, warm, medium), happiness (bright, happy, apathetic, sad), and the veracity of an argument (absolutely right, right, counter-argumentative, inconsistent, false, totally wrong).

Fuzzy logic is a research area focused on uncertainty treatment and a family of mathematical models dedicated to... Continue reading "Understanding Fuzzy Logic and Backpropagation in Neural Networks" »

CPU Internal Registers

Internal registers are a set of temporary storage units available to the Central Processing Unit (CPU) for its operation. They serve as high-speed storage locations within the CPU itself.

The size of these registers depends on the function to be performed and the type of CPU. They generally match the size of the Data Bus or the Address Bus.

Classification of CPU Registers

CPU registers are broadly classified into two main types:

• Inaccessible Registers: Not directly controllable by the user.
• Accessible Registers: Controllable by the user.

Inaccessible Registers

Inaccessible registers are those whose operation or content the user cannot directly control. They are for the exclusive and restricted use of the CPU. From the user's... Continue reading "CPU Register Types and Functions" »