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

Sort by
Subject
Level

Deadlock and Semaphores: Concurrency in Operating Systems

Classified in Computers

Written on in English with a size of 2.21 KB

Understanding Deadlock

A deadlock is a critical situation in which two or more computer programs, sharing the same resource, effectively prevent each other from accessing that resource. This results in both programs ceasing to function or becoming unresponsive.

Historically, the earliest computer operating systems ran only one program at a time, making all system resources available to that single program. As operating systems evolved to run multiple programs concurrently through interleaving, programs initially had to specify their resource needs in advance to avoid conflicts.

The advent of dynamic resource allocation, where programs could request further resources after execution began, introduced the problem of deadlocks. Addressing deadlocks... Continue reading "Deadlock and Semaphores: Concurrency in Operating Systems" »

Karma: 8%
Visits: 0

Content

Classified in Computers

Written on in English with a size of 5.21 KB

Primary Key : A Primary Key is the minimal set of attributes of a table that has the task to uniquely identify the rows, or we can say the tuples of the given particular table.It is the first key which is used to identify one and only one instance of an entity uniquely. An entity can contain multiple keys as we saw in PERSON table. The key which is most suitable from those lists become a primary key. In the EMPLOYEE table, ID can be primary key since it is unique for each employee. In the EMPLOYEE table, we can even select License_Number and Passport_Number as primary key since they are also unique.For each entity, selection of the primary key is based on requirement and developers.

Foreign key :A foreign key is different from a super key,

... Continue reading "Content" »

Karma: 8%
Visits: 0

Structural and Behavioral Design Patterns in Software Development

Classified in Computers

Written on in English with a size of 2.12 KB

Structural Design Patterns

Decorator - Adds additional functionality to a class

Adapter - 'adapts' one interface for a class into one that the client expects

Façade - creates a simplified interface from an existing one

Flyweight - A high quantity of objects share common properties to save space.

Bridge - decouples an abstraction from its implementation so that the two can vary independently.

Behavioral Design Patterns

Chain of Responsibility - Linked list of handlers

Command - Enables all the info for a request to be contained within a single object.

Interpreter - Developing domain specific languages

Iterator - Sequentially access elements of an aggregate object.

Mediator - Removes the need for classes to communicate with each other directly.

Observer... Continue reading "Structural and Behavioral Design Patterns in Software Development" »

Karma: 8%
Visits: 0

Understanding the Internet: Core Concepts and Technologies

Classified in Computers

Written on in English with a size of 4.72 KB

Understanding the Internet: A Global Network

The Internet is a global network of interconnected computers that any device can join. It functions as a Wide Area Network (WAN), which is essentially a series of connected Local Area Networks (LANs).

Data packets are transmitted between computers using protocols that govern how information is sent and received.

Key Internet Technologies and Services

Technologies and services available over the Internet include:

  • Web Pages: HTML documents presenting images, sound, and text, accessed via a web browser.
  • Web Applications: Software accessed through a web browser.
  • Native Applications: Applications developed for specific devices (e.g., smartphones), accessible without a browser.
  • Email: Electronic mail communication.
... Continue reading "Understanding the Internet: Core Concepts and Technologies" »
Karma: 8%
Visits: 0

Data Project Management: A Comprehensive Guide to DR, MVP, and Data Pipelines

Classified in Computers

Written on in English with a size of 3.25 KB

Data Project Management: A Comprehensive Guide

Goal Setting: The Foundation of Project Planning

Every project requires a clear destination to determine its success. Goal setting is the first step in project planning, providing a roadmap for the project's journey.

Tools & Skills: Assessing Project Resources

The upper blocks of DR (Data Requirements) focus on evaluating the resources necessary for data project implementation. These resources include:

  • Hard Resources: Data, software tools, processing
  • Soft Resources: Skills, domain expertise, human resources for execution

Process & Value: Implementation and Delivery

The lower blocks of DR concentrate on project implementation and delivery. DR serves as a planning tool, helping project managers:

  • Identify
... Continue reading "Data Project Management: A Comprehensive Guide to DR, MVP, and Data Pipelines" »
Karma: 8%
Visits: 0

Embed and Link Objects in Presentations: Best Practices

Classified in Computers

Written on in English with a size of 3.01 KB

Inserting Tables into Slides

In the Insert Object dialog box, click the Create From File option and click Browse to locate and choose the document or spreadsheet that contains the table. By default, the presentation software will insert the table. When you click OK, the entire document or spreadsheet is imported to your slide. Double-click the inserted text to remove extra text if the document contains more than the table. If you check the Link checkbox while inserting, after you update the table in the document or spreadsheet, then right click on the imported table in the presentation software, and select the option Update Link, the embedded table gets updated automatically. Drag and drop the table on the slide to position it.

Chart Design Principles

Convey... Continue reading "Embed and Link Objects in Presentations: Best Practices" »

Karma: 8%
Visits: 0

Java Programming Concepts and Functions

Classified in Computers

Written on in English with a size of 2.41 KB

public static void main(String[] args) {
Scanner entrada = new Scanner(System.in);
String frase= entrada.nextLine();
Stack invertidas = new Stack();
Queue ordenadas = new LinkedList();
for(int i=0;i char letra= frase.charAt(i);
if(Character.isLetter(letra)){
invertidas.push(Character.toLowerCase(letra));
ordenadas.add(Character.toLowerCase(letra));
}
}
while(!invertidas.isEmpty() && invertidas.peek()==ordenadas.peek()) {
invertidas.pop();
ordenadas.poll();
}
if(invertidas.isEmpty() && ordenadas.isEmpty()){
System.out.println( 'A frase é palíndrome');
}
else{
... Continue reading "Java Programming Concepts and Functions" »
Karma: 8%
Visits: 0

ABAP Dictionary Fundamentals: Key Concepts and Practical Applications

Classified in Computers

Written on in English with a size of 4.28 KB

ABAP Dictionary Fundamentals

Key Concepts and Practical Scenarios

Question 2: Creating ABAP Dictionary Objects

What can you create using the ABAP Dictionary? (Choose three)

  • A. Domains
  • B. Type pools
  • C. Transparent tables

Correct Answers: A, B, C

Question 14: Resolving Enhancement Category Warnings

You created a transparent table and during activation received a warning message: 'Enhancement category for table missing'. What must you do to eliminate this warning message?

  • A. Select any option other than 'Not Classified' from the enhancement category.

Correct Answer: A

Question 20: Assigning Fixed Values in ABAP Dictionary

To which ABAP Dictionary definition can you assign fixed values?

  • D. Domain

Correct Answer: D

Question 25: Understanding Transparent Table Relationships

In... Continue reading "ABAP Dictionary Fundamentals: Key Concepts and Practical Applications" »

Karma: 8%
Visits: 0

Understanding Time Complexity in Sorting Algorithms

Classified in Computers

Written on in English with a size of 12.09 KB

1. What is recurrence for worst case of QuickSort and what is the time complexity in Worst case? Recurrence is T(n) = T(n-1) + O(n) and time complexity is O(n^2) 2. Suppose we have a O(n) time algorithm that finds median of an unsorted array. Now consider a QuickSort implementation where we first find median using the above algorithm, then use median as pivot. What will be the worst case time complexity of this modified QuickSort. O(nLogn)  3. Given an unsorted array. The array has this property that every element in array is at most k distance from its position in sorted array where k is a positive integer smaller than size of array. Which sorting algorithm can be easily modified for sorting this array and what is the obtainable time complexity?

... Continue reading "Understanding Time Complexity in Sorting Algorithms" »
Karma: 8%
Visits: 0

Excel Pivot Tables, Search and Logic Functions, Macros

Classified in Computers

Written on in English with a size of 16.44 KB

Explanation

10.1 Pivot tables

What is a pivot table? It is one of the most powerful tools in Excel. They are also called “dynamic” because the data on them can be changed by rearranging or changing the position of the column and row headers in an easy and quick way.

The use of a dynamic table is to obtain information summaries from our data grid in order to be able to quickly analyze big volumes of information. These type of tables can be used in situations such as:

  • When you have a table with rows that have different date and you need to organize the information by time periods (month, semester, etc.)
  • When you need to change the arrangement in the rows or column cells to show different perspectives from the same data set.


Follow these steps to... Continue reading "Excel Pivot Tables, Search and Logic Functions, Macros" »

Karma: 8%
Visits: 0