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

MapReduce is a computing paradigm for processing data that resides on hundreds of computers, which has been popularized recently by Google, Hadoop, and many others. The paradigm is extraordinarily powerful, but it does not provide a general solution to what many are calling “big data,” so while it works particularly well on some problems, some are more challenging. This book will teach you what problems are amenable to the MapReduce paradigm, as well as how to use it effectively. At first glance, many people do not realize that MapReduce is more of a framework than a tool. You have to fit your solution into the framework of map and reduce, which in some situations might be challenging. MapReduce is not a feature, but rather a constraint.... Continue reading "Understanding MapReduce Design Patterns" »

Python Fundamentals: Practical Code Examples

This document presents a collection of basic Python code snippets, demonstrating fundamental programming concepts such as conditional statements, loops, data input, and list manipulation. Each example is designed to illustrate a specific programming principle, making it ideal for beginners learning Python.

Compare Car Top Speeds with Python

This Python script compares two user-entered car speeds to determine which is faster, showcasing basic input and conditional logic.

car_a = int(input("Please enter the top speed of a Ferrari: "))
car_b = int(input("Please enter the top speed of a Lamborghini: "))

if car_a >= car_b:
    print("The fastest car is a Ferrari.")
elif car_b > car_a:
    print("The

Digital Image Processing Tutorial

Digital Image Processing Tutorial provides basic and advanced concepts of image processing. Our Digital Image Processing Tutorial is designed for beginners and professionals both.

Digital image processing is used to manipulate digital images by the use of algorithms. For processing digital images, the most common software that is used widely is Adobe Photoshop.

Our digital image processing tutorial includes all topics of digital image processing such as introduction, computer graphics, signals, photography, camera mechanism, pixel, transaction, types of images, etc.

What Is Digital Image Processing (DIP)?

Digital Image Processing (DIP) is a software which is used to manipulate digital images by the use of a computer... Continue reading "Digital Image Processing Tutorial for Beginners and Professionals" »

Transition Phase

The transition phase is entered when a baseline is mature. A usable subset of the system has been built with acceptable quality levels and user documentation. It can be deployed to the user community.

• For some projects, the transition phase marks the starting point for another version of the software system.
• For other projects, the transition phase signifies the complete delivery of the software system to a third party responsible for operation, maintenance, and enhancement.

Objectives of the Transition Phase

• Achieve user independence (users can support themselves).
• Ensure the deployment baseline is complete and consistent with the criteria in the project agreement.
• Ensure the final baseline can be built as rapidly and cost-effectively

ASCII Code

American Standard Code for Information Interchange. A code in which each alphanumeric character is represented as a number from 0 to 127, translated into a 7-bit binary code for the computer. ASCII is used by most microcomputers and printers, and because of this, text-only files can be transferred easily between different kinds of computers.

Availability

A measure of how easy or difficult it is to obtain a piece of hardware or a computer application.

Backbone

High-speed lines or connections that form the major access pathways within the Internet.

Bandwidth

The capacity of a networked connection. Bandwidth determines how much data can be sent along the networked wires. Bandwidth is particularly important for Internet connections, since greater... Continue reading "A Glossary of Computer and Internet Terms" »

Socket.io Emitting Patterns

io.on('connect', onConnect);

function onConnect(socket) {
  // Sending to the client
  socket.emit('hello', 'can you hear me?', 1, 2, 'abc');

  // Sending to all clients except sender
  socket.broadcast.emit('broadcast', 'hello friends!');

  // Sending to all clients in 'game' room except sender
  socket.to('game').emit('nice game', "let's play a game");

  // Sending to all clients in 'game1' and/or 'game2' room, except sender
  socket.to('game1').to('game2').emit('nice game', "let's play a game (too)");

  // Sending to all clients in 'game' room, including sender
  io.in('game').emit('big-announcement', 'the game will start soon');

  // Sending to all clients in namespace 'myNamespace', including sender
  io.

CSS Pseudo-Class Reference

VHDL Code Examples for Digital Logic Design

This document presents several VHDL code examples demonstrating the implementation of various digital logic circuits, including custom combinational functions and a priority encoder. These examples illustrate fundamental VHDL constructs for hardware description.

Custom Combinational Logic Function (EFC_17_F) - Decoder Label

This VHDL module, named EFC_17_F, implements a specific combinational logic function. In the original context, it was labeled as a "decoder." It takes four standard logic inputs (P1, P0, M1, M0) and produces a single standard logic output (C). The output C is asserted ('1') for specific input combinations, effectively acting as a custom boolean function.

LIBRARY IEEE;
USE IEEE.STD_

Introducing Networks

A network is created when more than one device is connected together. A network can be a small collection of computers connected within a building (e.g. a school, business, or home) or it can be a wide collection of computers connected around the world.

Advantages

• Communication – it is easy (and often free) to communicate using email, text messages, voice calls, and video calls.
• Roaming – if information is stored on a network, it means users are not fixed to one place. They can use computers anywhere in the world to access their information.
• Sharing information – it is easy to share files and information over a network. Music and video files, for instance, can be stored on one device and shared across many computers, so

Application Software

System Software

Operating System

Why OS?

Operating System Function

OS Goals

Types of Operating Systems

• Single Process Operating System
• Batch-Processing Operating System
• Multiprogramming Operating System
• Multitasking Operating System
• Multi-Processing Operating System
• Distributed System
• Real Time OS

Program

Process

Thread

Multi-tasking vs Multi-Threading

Thread Scheduling

Thread Context Switching vs Process Context Switching

User Space

Kernel

Functions of Kernel

• Process Management
• Memory Management
• File Management
• I/O Management

Type Of Kernel

• Monolithic
• Micro
• Hybrid
• Nano

System Calls

Types

• Process Management
• Device Management
• File Management
• Information Management
• Communication Management

Firmware: SW embedded in HW (microprocessor -> microcontroller)

What