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

Javascript Continued

Proximity

Proximity is all about using visual spaces to show relationships in your content. We can group the items in blocks of text or elements in the graphic to take visual emphasis.

White Space

White space, also known as negative space, refers to the spaces between your content, between lines, and even the margins. White space defines and separates different sections.

Alignment

We can separate text boxes, images, etc. by imagining their content as a range inside of a grid. Centering the images to the text and using equal size margins can create a visually pleasing alignment.

Contrast

Contrast means that one item is different from another. We can create contrast using color, size, shape, or contrasting styles of text. Hierarchy, a visual technique... Continue reading "Using Proximity, White Space, Alignment, Contrast, and Repetition in Design" »

Key Network Concepts and Design Principles

Essential Network Terminology

Usability

The ease with which network users can access the network and its services. This includes goals for simplifying user tasks.

Management (Fault, Configuration, Accounting, Performance, Security)

The five key areas of network management: Fault Management, Configuration Management, Accounting Management, Performance Management, and Security Management.

Bandwidth

The data-carrying capacity of a circuit, measured in bits per second (bits/sec).

Throughput

The quantity of error-free data transmitted per unit of time by a circuit, measured in bits/bytes per second or packets per second.

Five Nines

High availability of service, commonly taken to mean 99.999% uptime.

Silent Failure

A

Introduction to Architecture

• Instruction Set Architecture (ISA): An assembly language programmer's view of the microprocessor.
• Assembler: Translates symbolic assembly language code into binary machine language code.

Computer Performance Metrics

• Execution Time (Response Time): Time to complete a program or task.
• Throughput (Bandwidth): Number of programs or tasks completed per time unit.
• Execution Time (t_exec, i.e., elapsed time, wall time, real time, response time): Elapsed seconds from start to finish. Includes:
  • Executing instructions
  • Disk access
  • Memory access
  • I/O activities
  • OS overhead
• User CPU Time (t_cpu(user)): Seconds the CPU spends executing the program's instructions.
• System CPU Time (t_cpu(sys)): Seconds the CPU spends executing OS (kernel) instructions

Certainly! Here is a cheat sheet for computer architecture:

1. Central Processing Unit (CPU)

• The "brain" of the computer that executes instructions.
• Consists of the Control Unit (CU) and the Arithmetic Logic Unit (ALU).
• Fetches instructions from memory, decodes them, and executes them.

2. Memory Hierarchy

• Registers: Fastest and smallest storage units located within the CPU.
• Cache: High-speed memory that stores frequently accessed data.
• Main Memory (RAM): Larger storage used to hold data and instructions.
• Secondary Storage: Non-volatile storage devices like hard drives and SSDs.

3. Instruction Cycle

• Fetch: The CPU fetches the next instruction from memory.
• Decode: The instruction is decoded to determine the operation.
• Execute: The instruction is executed

MATLAB Statistical Analysis of Student Weights

Analyze the weight of 30 students to find the minimum, maximum, average, standard deviation, and plot a histogram.

>> a=[ 71 82 65 75 77 91 59 84 89 81 73 91 82 75 96 85 69 76 81 92 84 79 77 95 81 79 84 85 76 82]

a = Columns 1 through 12
    71 82 65 75 77 91 59 84 89 81 73 91

Columns 13 through 24
    82 75 96 85 69 76 81 92 84 79 77 95

Columns 25 through 30
    81 79 84 85 76 82

>> max(a)
ans = 96

>> min(a)
ans = 59

>> mean(a)
ans = 80.5333

>> std(a)
ans = 8.4516

>> hist(a)

Plotting Trigonometric Functions in MATLAB

Follow these steps to plot trigonometric functions:

• Plot the value of the cosine within [0, 2π] with a step of π/20.
• Label the axes and add

Librerías Estándar del Lenguaje C

A continuación se detallan las cabeceras principales de la biblioteca estándar de C (ANSI C) junto con sus funciones más representativas.

stdio.h: Entrada y Salida Estándar

La cabecera <stdio.h> provee capacidades esenciales para operaciones de entrada, salida y manejo de archivos.

• clearerr
• fclose
• feof
• ferror
• fflush
• fgetc
• fgetpos
• fgets
• fopen
• formato
• fprintf
• fputc
• fputs
• fread
• freopen
• fscanf
• fseek
• fsetpos
• ftell
• fwrite
• getc
• getchar
• gets
• perror
• printf
• putc
• putchar
• puts
• remove
• rename
• rewind
• scanf
• setbuf
• setvbuf
• sprintf
• sscanf
• tmpfile
• tmpnam
• ungetc
• vfprintf
• vprintf
• vsprintf

stdlib.h: Utilidades Generales y Memoria

La librería <stdlib.h> contiene funciones para gestión dinámica de memoria, control de procesos y conversiones numéricas.

• abort
• abs
• atexit
• atof
• atoi
• atol
• bsearch
• calloc
• div
• exit
• free
• getenv
• labs
• ldiv
• malloc
• mblen
• mbstowcs
• mbtowc
• qsort
• rand
• realloc
• srand
• strtod
• strtol
• strtoul
• system
• wctomb

string.

1. Which of the following statements about MPEG is not correct?

• a. MPEG-1/2/4 are multimedia standards related to video and audio compression.
• b. MPEG-7 is a multimedia content description standard that standardizes the extraction process and usage of audiovisual descriptors.
• c. MPEG-7 is a multimedia content description standard that standardizes the syntax and semantics of audiovisual descriptors.

2. The Dominant Color Descriptor (DCD) captures…

• a. The spatial distribution of the colors in an image using by default the YUV color space.
• b. A maximum of eight representative colors using by default the RGB color space.
• c. All the colors in the RGB color space with a larger percentage than 10.

3. The Color Structure Descriptor (CSD)…

• a. Does not capture

Building a Sudoku Solver in Java with Backtracking

This document presents a Java implementation of a Sudoku solver, utilizing a classic backtracking algorithm. The code demonstrates how to represent a Sudoku board, check for valid moves, and recursively find a solution to the puzzle.

Initial Sudoku Puzzle Setup

The Sudoku board is represented as a 2D integer array. A value of 0 indicates an empty cell that needs to be filled.

int[][] board = {
  { 8, 0, 0, 0, 0, 0, 0, 0, 0 },
  { 0, 0, 3, 6, 0, 0, 0, 0, 0 },
  { 0, 7, 0, 0, 9, 0, 2, 0, 0 },
  { 0, 5, 0, 0, 0, 7, 0, 0, 0 },
  { 0, 0, 0, 0, 4, 5, 7, 0, 0 },
  { 0, 0, 0, 1, 0, 0, 0, 3, 0 },
  { 0, 0, 1, 0, 0, 0, 0, 6, 8 },
  { 0, 0, 8, 5, 0, 0, 0, 1, 0 },
  { 0, 9, 0, 0, 0, 0, 4, 0, 0 }
};

Implementing