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

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Understanding Databases: Concepts and Key Components

Posted by aakankshajayant and classified in Computers

Written on in English with a size of 4.58 KB

What is a Database?

A database is an organized collection of data, visualized as a container of information. The data is typically organized to model relevant aspects of reality. A Database Management System (DBMS) is a software package with computer programs that controls the creation, maintenance, and use of a database. It allows organizations to conveniently develop databases for various applications.

A database is an integrated collection of data records, files, and other objects. A DBMS allows different user application programs to concurrently access the same database. Typically, databases available on database servers are accessed through command-line or graphical user interface tools, referred to as front-ends; database servers are referred... Continue reading "Understanding Databases: Concepts and Key Components" »

Understanding Counting Principles, Knowledge Types, and Geometric Thinking

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The Counting Principles

Counting is the action of finding the number of elements in a finite set of objects. Here are the key principles:

  1. The Stable-Order Principle: To count effectively, the list of words used (like one, two, three) must be in a repeatable order.
  2. The One-to-One Principle: This involves assigning one, and only one, distinct counting word to each item being counted.
  3. The Cardinal Principle: When the one-to-one and stable-order principles are followed, the number name given to the final object in a collection represents the total number of items in that collection.
  4. The Order-Irrelevance Principle: This principle highlights that the order in which items are counted doesn't affect the total count.
  5. The Abstraction Principle: These counting
... Continue reading "Understanding Counting Principles, Knowledge Types, and Geometric Thinking" »

3D Cube Transformations in OpenGL: Scaling, Translation, and Rotation

Posted by aditya dani and classified in Computers

Written on in English with a size of 2.4 KB

Introduction

This program demonstrates how to draw a 3D cube in OpenGL and perform various transformations on it, including scaling, translation, and rotation about one axis.

Code

#include <GL/glut.h>

bool movingRight = false;
float xLocation = 0.0f;

void display() {
  glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
  glClear(GL_COLOR_BUFFER_BIT);
  glLoadIdentity();
  glTranslatef(0.0f, 0.0f, -5.0f);
  glTranslatef(xLocation, 0.0f, 0.0f);
  glutWireCube(2.0f);
  glutSwapBuffers();

  if (movingRight)
    xLocation -= 0.05f;
  else
    xLocation += 0.05f;

  if (xLocation < -3.0f)
    movingRight = false;
  else if (xLocation > 3.0f)
    movingRight = true;
}

void reshape(int width, int height) {
  glViewport(0, 0, (GLsizei)width, (GLsizei)
... Continue reading "3D Cube Transformations in OpenGL: Scaling, Translation, and Rotation" »

Refer to the exhibit. A network administrator has segmented the network into two VLANs and configured Router1 for inter-VLAN routing. A test of the network, however, shows that hosts on each VLAN can only access local resources and not resources on t

Classified in Computers

Written on in English with a size of 20.53 KB

  1.  A network technician is configuring port Security on a LAN switch interface. The security policy requires host MAC Addresses to be learned dynamically, stored in the address table, and Saved to the switch running configuration. Which command does the technician Need to add to the following configuration to implement this Policy? Switch(config)# interface fa0/1 
    Switch(config-if)# switchport mode access 
    Switch(config-if)# switchport port-security

·Switch(config-if)# switchport port-security mac-address sticky

  1. On which switch interface would an Administrator configure an IP address so that the switch can be managed Remotely?

·VLAN 1

  1. Refer to the exhibit. Match the packets with Their destination IP address to the exiting interface on the router.
... Continue reading "Refer to the exhibit. A network administrator has segmented the network into two VLANs and configured Router1 for inter-VLAN routing. A test of the network, however, shows that hosts on each VLAN can only access local resources and not resources on t" »

Understanding Cisco IGRP and EIGRP Protocols

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Understanding IGRP Protocol

What is IGRP?

IGRP is a Cisco-specific protocol developed in the mid-1980s.

IGRP Advantages Over RIP

IGRP calculates a composite metric from a set of route variables. It can be implemented on networks of up to 255 hops in diameter. Additional advantages include:

  • Unequal-cost load sharing
  • An update period three times longer than RIP's
  • A more efficient update packet format

Unlike RIP, which uses UDP, the IGRP process is accessed directly from the IP layer as protocol 9.

IGRP Routing and Process Domains

Using domains allows isolating communications within one domain from others. IGRP uses two types: routing domains and process domains.

  • Routing domains: Defined by Autonomous System (AS) boundaries and communicate via Exterior Gateway
... Continue reading "Understanding Cisco IGRP and EIGRP Protocols" »

SDN

Classified in Computers

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OPENFLOW:

defines OpenFlow as the first standard communications interface defined between the control and forwarding layers of an SDN architecture. OpenFlow allows direct access to and manipulation of the forwarding plane of network devices such as switches and routers, both physical and virtual 


OPENFLOW CONFIG CONCEPTS


OF Capable Switch: Physical OF switch.  Can contain one or more OF logicalswitches.

OpenFlow Configuration Point: configurationservice

OF Controller: Controls logical switch via OFprotocol

Operational Context: OF logicalswitch

OF Queue: Queues of packets waiting forforwarding

OF Port: forwarding interface. May be physical orlogical.

OF Resource: ports, queues, certificates, flow tables and other  resources of OF capableswitches 

... Continue reading "SDN" »

Advantages of Address Aggregation and Key Characteristics of Routing Protocols

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Discuss the advantages of address aggregation (summarization) with respect to routing table size, routing update exchange, and routing optimization?

Route aggregation and subnetting shrink the size of routing tables used by routers. Without CIDR, a router must maintain many individual entries for routes within the same network. CIDR guarantees more efficient routing and reduces the number of CPU cycles when updating a routing table. It also reduces router memory requirements.

What are the key characteristics or requirements that should be fulfilled by any routing protocol?

A routing protocol should guarantee loop-free paths, calculate multi-hop optimal paths, use simple or composite network metrics, be scalable, converge rapidly, use network resources... Continue reading "Advantages of Address Aggregation and Key Characteristics of Routing Protocols" »

Managing Operating Systems on Workstations: The Big Three

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Managing operating systems on workstations boils down to three basic tasks: loading the system
software and applications initially, updating the system software and applications, and
configuring network parameters.
We call these tasks the Big Three.

The Five States

The diagram depicts five states: new, clean, configured,
unknown, and off.

  • New refers to a completely new machine.
  • Clean refers to a machine on which the OS has been installed
    but no localizations performed.
  • Configured means a correctly configured and operational
    environment.
  • Unknown is a computer that has been misconfigured or has
    become out of date.
  • Off refers to a machine that has been retired and powered off.

Transitioning Between States

There are many ways to get from one lifestyle... Continue reading "Managing Operating Systems on Workstations: The Big Three" »

Efficient Recruiting and Algorithm Design: Set Cover, Hamiltonian Path, and Longest Increasing Subsequence

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Set Cover to Efficient Recruiting

Input: Set U of elements, collection S1, ..., Sm of subsets of U, integer k ≥ 0

Construct an instance of the Efficient Recruitment Problem:

  • Sports are represented by U.
  • Applicants are represented by {1, ..., m}.
  • For every s ∈ U and 1 ≤ i ≤ m, M[s, i] = 'qualified' if s ∈ Si and 'not qualified' otherwise.

Steps:

  1. Call the oracle for Efficient Recruiting with input M and k.
  2. Return the result (yes or no) of the previous call.

Vertex Cover and Hitting Set

Graph: G = (V, E)

  • U = V(G)
  • Si = {u, v}, where (u, v) is an edge of G.

Vertex Cover ⇒ Hitting Set:

If C is a vertex cover for G of size k, then by definition, for every edge (u, v) in G, either u ∈ C or v ∈ C. Therefore, C is a solution for Hitting Set because... Continue reading "Efficient Recruiting and Algorithm Design: Set Cover, Hamiltonian Path, and Longest Increasing Subsequence" »

Network Fundamentals: DHCP, Subnetting, and Transport Protocols

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Dynamic Host Configuration Protocol (DHCP) Servers

What is a DHCP Server?

A DHCP Server is a network server that automatically provides and assigns IP addresses, default gateways, and other network parameters to client devices. It relies on the standard protocol known as Dynamic Host Configuration Protocol (DHCP) to respond to broadcast queries by clients.

Benefits of DHCP

A DHCP server automatically sends the required network parameters for clients to properly communicate on the network. Without it, the network administrator has to manually set up every client that joins the network, which can be cumbersome, especially in large networks. DHCP servers usually assign each client with a unique dynamic IP address, which changes when the client’s... Continue reading "Network Fundamentals: DHCP, Subnetting, and Transport Protocols" »