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

The 7 Layers of the OSI Model

The Open Systems Interconnection (OSI) model defines a networking framework to implement protocols in seven distinct layers. Understanding these layers is fundamental to grasping how data communication occurs across networks.

Application Layer (Layer 7)

The Application Layer, OSI Model Layer 7, supports application and end-user processes. Key functions include identifying communication partners, defining quality of service, considering user authentication and privacy, and identifying any constraints on data syntax. Everything at this layer is application-specific.

This layer provides application services for file transfers, e-mail, and other network software services. Examples of applications existing entirely at this... Continue reading "The 7 Layers of the OSI Model Explained for Networking Professionals" »

The Scrum Guide

Framework for developing and sustaining complex adaptive problems, while productively and creatively delivering products of the highest possible value. Scrum is lightweight, simple to understand and difficult to master.

The Scrum Team

The Scrum Team: Self-organizing teams choose how best to accomplish their work, rather than being directed by others outside the team. It is designed to optimize flexibility, creativity, and productivity. It consists of:

• The Product Owner: Responsible for maximizing the value of the product and the work of the team. Responsible for managing the Product Backlog.
• The Development Team: Professionals who do the work of delivering a potentially releasable increment of 'Done' product at the end of each Sprint.

What is a software and what is a good software?

A software is a program on a computer which contains information and data. A good software is the one that fulfills the needs and hasn’t got bugs.

Software vs Hardware

Software: not touchable, variable and implemented in order to achieve goals. Hardware: invariable

SOFTWARE ETHICS:

• Confidentiality - Not telling the others because they can copy.
• Competence - To know what you’re doing.
• Intellectual property rights - not steal others ideas because it’s not moral.
• Computer misuse - don’t do things that you are not allowed to.
• Stuxnet: virus that will destroy softwares and hardwares.

SOFTWARE EVALUATION PROCESS:

• Specification: What do I need?
• Development: The programmer does it.
• Validation: Does it work?

C++ Code Examples: Data Filtering and Sorting

This document presents two fundamental C++ programming examples. The first demonstrates how to process user input to extract and display only unique integer values, effectively removing duplicates. The second illustrates the classic Bubble Sort algorithm for arranging elements in ascending order within a std::vector.

Filtering Duplicate Integers in C++

This C++ program prompts the user to enter 20 integers. It then processes these inputs to identify and store only the unique values, discarding any duplicates. Finally, it displays the list of non-duplicate integers.

Program Description: Unique Element Extraction

• Initializes an array a of size 20 to store unique elements, along with a subscript to track

What is bleed? When any image or element on a page touches the edge of the page, extending beyond the trim edge leaving no margin it is said to bleed. It may bleed or extend off one or more sides.

What is slug? Non-printing information (such as a title and date) used to identify a document outside bleed area.

What is Trim - The final size of a printed page after excess edges of paper have been cut off What is Gutter - The area between columns on a page or the blank space between two facing pages in print

Match each file format with the kind of information it would likely be used to save?
o TIFF = A loss-less bit-mapped file format for high-resolution photographic images, typically in print
a EPS = A vector-based file format for high-resolution... Continue reading "Understanding Bleed, Slug, Trim, and Gutter in Print Design" »

Javascript

The async attribute allows the browser to process the web page concurrently with loading and processing the JavaScript.

The defer attribute allows the browser to load the web page concurrently with loading the JavaScript, but the JavaScript is not processed until the web page is completely loaded.script src="bootstrap.js" async>script>

A change event is caused by an element value being modified. Ex: Selecting an item in a radio button group causes a change event.

An input event is caused when the value of an input or textarea element is changed.

A load event is caused when the browser completes loading a resource and dependent resources. Usually load is used with the body element to execute code once all the web page's CSS, JavaScript,

◦ Performs an action if a condition is true and performs a different action if the condition is false.

◦ Double-selection statement—selects between two different actions (or groups of actions).

}switch statement

◦ Performs one of several actions, based on the value of an expression.

◦ Multiple-selection statement—selects among many different actions (or groups of actions).

Iteration Statements in Java

}Four iteration statements (also called iteration statements or looping statements)

◦ Perform statements repeatedly while a loop-continuation condition remains true.

}

while and for statements perform the action(s) in their bodies zero or more times

◦ if the loop-continuation condition is initially false, the body will not execute.

}The do…while... Continue reading "Java Control Statements and Operators" »

This document presents a C++ implementation of a Queue data structure, demonstrating its core functionalities and operations. The Queue is implemented using a linked list, adhering to the First-In, First-Out (FIFO) principle.

Queue Class Definition

The Queue class encapsulates the data members and member functions necessary to manage a queue. Note that the Node struct/class is assumed to be defined elsewhere, typically as struct Node { double info; Node* link; };.

class Queue
{
private:
    Node* front;
    Node* rear;
    int count;
    double info; // This member 'info' within the Queue class itself seems unused in the provided code.
public:
    // Constructor: Should be 'Queue();' without 'void'. Implementation is missing.
    Queue();

CH6

Predictive Modeling Techniques

61) Predictive modeling is perhaps the most commonly practiced branch in data mining. What are three of the most popular predictive modeling techniques?

Answer:

• Artificial neural networks
• Support vector machines
• k-nearest neighbor

62) Why have neural networks shown much promise in many forecasting and business classification applications?

Answer: Because of their ability to "learn" from the data, their nonparametric nature (i.e., no rigid assumptions), and their ability to generalize.

Understanding Neural Networks

63) Each ANN is composed of a collection of neurons that are grouped into layers. One of these layers is the hidden layer. Define the hidden layer.

Answer: A hidden layer is a layer of neurons that takes input... Continue reading "Predictive Modeling Techniques in Data Mining" »

Chapter 1: Foundations of Object-Oriented Programming

Data Encapsulation with Classes

The starting point of object-oriented programming is to provide a more faithful implementation of the notion of “type” in programming. The programming languages we are familiar with come with standard built-in types that we can assign to variables and values:

Built-in Programming Types

• In C, we can use int, float, double, char, etc.
• In Haskell, similarly, we can use Int, Float, Char, Bool, etc.

In addition, programming languages provide a way to assign a single name to a collection of values of the same type. The nature of this collection is determined by the underlying architecture assumed by the programming language.

Collections and Data Structures

Arrays in