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

Differences Between TCP and UDP

• TCP: Connection-oriented, bytes delivered in order, arbitrary length content, flow control matches sender to receiver, and congestion control matches sender to network.
• UDP: Connectionless, messages may be lost, limited message size, can send regardless of receiver state, and can send regardless of receiver network.

TCP Connection Management

Explain using figures where and how the 3-way handshaking is used. Explain using figures how TCP releases connections (refer to the other side of this paper).

• Normal case
• Simultaneous connect

Computing Adaptive Timeout

Keep smoothed estimates of the RTT and variance in RTT. Update estimates with a moving average. Set timeout to a multiple of estimates to estimate the upper RTT in... Continue reading "Essential Networking Concepts: TCP, UDP, and Congestion" »

Optimization Problem and LP Relaxation

The objective function for an optimization problem is: Min 3x – 2y, with constraints x ≥ 0, y ≥ 0. x and y must be integers. Suppose that the integer restriction on the variables is removed. If so, this would be a familiar two-variable linear program; however, it would also be an example of an LP relaxation of the integer linear program.

Integers in Linear Programs

Integers cannot be used in linear programs.

• False

Simple Linear Regression Model

In a simple linear regression model, y = b0 + b1x + eb1, b1 represents the intercept.

Time Series Recurring Pattern

A time series that shows a recurring pattern over one year or less is said to follow a cyclical pattern.

Binary Integer Program Variables

In binary integer... Continue reading "Fundamentals of Optimization and Statistical Modeling" »

EXT2018.OA´WOMEN REALLY´

1.a-P1: A recent study found that women tend to live longer than men. b-P3: The academics also discovered that women have a stronger immune system.

• a-harsh
• b-hardship
• c-underpinnings
• d-outlive

4.p1: Danish researchers analyzed 19th-century data. p2: Research showed that women outlive men. p3: Males have a higher mortality rate even if...

ORD2018.OB·`Shop hires...`

1.a-P2: But it is important for businesses to understand their customers. b-P4: We thought it was an emotional and exciting experience.

• a-actually
• b-aware
• c-stressful
• d-understanding

4.p1: At the shop, Fabio performed. p2: When Fabio, the staff. p3: The staff had become...

ORD2017.OB`The victorian...`

1.a-P2: People would gather to observe. b-P3: The tableaus were a frozen... Continue reading "Gender Disparities in Mortality Rates and Immune System Function" »

• Automovilismo
• Inicio

Escudería:
Precio:
Clave:

Disponibilidad para probar coches:

SíNo
Fecha de alta:

¿Deseas recibir información de automóviles?:

Sí

Tipos de coches:

AudiMercedesBMWJaguar
Comentarios

Office Facilities and Personnel

• Assist: Be in charge of, describe, develop, explain how to use, hire (contatar), sell.
• Cafeteria: Car park, conference room, ground floor, kitchen, lobby, maintenance, reception, stockroom, toilet, top floor, warehouse.
• Appointment (cita): Business card, clerk (dependiente), do business, employee, employer, escalator, interview, name plate, receptionist, research and development department, title.

Administrative Tasks and Business Operations

• Answer incoming calls: Data entry, deliver the message, distribute the incoming mail, file documents (archivar), keep a log (mantener registro), keep track of (llevar registro), order supplies, prepare a presentation, receive visitors, schedule a meeting, screen a call, search

Client and Server Web Interaction

Steps for a Client (Browser)

• Determine the protocol (HTTP).
• Ask DNS for the IP address of the server.
• Make a TCP connection to the server.
• Send a request for the page; the server sends it back.
• Fetch other URLs as needed to display the page.
• Close idle TCP connections.

Steps for a Server

• Accept a TCP connection from the client.
• Get the page request and map it to a resource (e.g., file name).
• Get the resource (e.g., file from disk).
• Send the contents of the resource to the client.
• Release idle TCP connections.

Challenges in P2P Networking

1. How do peers find each other?
2. How do peers support rapid content downloads?
3. How do peers encourage each other to upload?

BitTorrent Protocol Download Steps

1. Start with the torrent description.