Notes, summaries, assignments, exams, and problems for Computer science

Logistic Regression Implementation

1. Upload and Prepare Dataset

from google.colab import files
uploaded = files.upload()

2. Import Libraries

import numpy as np
import pandas as pd
import matplotlib.pyplot as plt
import seaborn as sns
from sklearn.model_selection import train_test_split
from sklearn.preprocessing import StandardScaler
from sklearn.linear_model import LogisticRegression
from sklearn.metrics import confusion_matrix

3. Load and Split Data

data = pd.read_csv("Social_Network_Ads.csv")
X = data[['Age','EstimatedSalary']]
y = data['Purchased']
X_train, X_test, y_train, y_test = train_test_split(X, y, test_size=0.25, random_state=0)

4. Feature Scaling and Model Training

sc = StandardScaler()
X_train = sc.fit_transform(X_train)
X_test = sc.

Understanding XML Parsers and Their Types

An XML parser is a software library used to read and process XML documents. It validates XML syntax and converts data into a usable format.

Types of XML Parsers

• DOM Parser (Document Object Model)
  • Loads the complete XML document into memory.
  • Represents XML as a tree structure.
  • Allows reading and modifying XML.
  • Features: Easy navigation, supports editing, but is memory-intensive.
• SAX Parser (Simple API for XML)
  • Reads XML line by line.
  • Event-driven parser.
  • Faster and memory-efficient.
  • Features: Suitable for large XML files, but cannot modify XML easily.

Benefits of Web Services

• Platform Independent: Works across Windows, Linux, Java, PHP, and more.
• Language Independent: Applications developed in different languages can

5G Enabling Technologies

5G is made possible by a combination of advanced radio, network, and computing technologies. These enabling technologies work together to deliver high data rates, ultra-low latency, massive connectivity, and high reliability.

1. Millimeter Wave (mmWave) Communication

5G uses high-frequency bands (typically 24 GHz–100 GHz) known as millimeter waves.

• Provides extremely high data rates
• Suitable for dense urban areas, stadiums, and hotspots
• Limited range, so it requires more base stations and small cells

2. Massive MIMO (Multiple Input Multiple Output)

Uses a large number of antennas at the base station.

• Increases spectral efficiency
• Supports multiple users simultaneously
• Improves data rates and coverage

3. Network Slicing

Divides...

Sound in Unity

Definition: Sound in Unity is used to add audio effects and background music to games.

Components

• Audio Source: Plays sound
• Audio Clip: The audio file
• Audio Listener: Receives sound

Concept and Application

The Audio Source plays the sound, while the Listener receives it. This adds realism to games and is used for both background music and sound effects.

Canvas and UI in Unity

Definition: The Canvas is used to create user interface elements like buttons, text, and menus in Unity.

Components

• Canvas
• Button
• Text

Concept and Application

UI elements are placed inside the Canvas to facilitate user interaction. It is used in all games to display information such as scores, health, and menus.

Artificial Intelligence (AI) in Unity

Definition: AI in Unity...

Palindrome and Digit Sum Calculation

#include <iostream>
using namespace std;
int main() {
    int n, r, rev = 0, sum = 0, t;
    cin >> n; t = n;
    while (n) {
        r = n % 10;
        rev = rev * 10 + r;
        sum += r;
        n /= 10;
    }
    cout << (t == rev ? "Palindrome" : "Not");
    cout << "\nSum=" << sum;
}

Matrix Addition in C++

#include <iostream>
using namespace std;
int main() {
    int a[10][10], b[10][10], c[10][10], r, col;
    cin >> r >> col;
    for (int i = 0; i < r; i++)
        for (int j = 0; j < col; j++) cin >> a[i][j];
    for (int i = 0; i < r; i++)
        for (int j = 0; j < col; j++) cin >> b[i][j];
    for (int i = 0; i < r; i+

User Registration Form

Name:

Password:

Gender:
Male
Female

Hobbies:
Reading
Music

City:
SuratAhmedabad

Java Programming Examples

1. Simple Interest Calculation

import java.util.Scanner;
class SimpleInterest {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        float p, r, t, si;
        p = sc.nextFloat();
        r = sc.nextFloat();
        t = sc.nextFloat();
        si = (p * r * t) / 100;
        System.out.println("Simple Interest = " + si);
    }
}

2. Call Cost Calculation

import java.util.Scanner;
class CallCost {
    public static void main(String args[]) {
        Scanner sc = new Scanner(System.in);
        int min;
        float rate, cost;
        min = sc.nextInt();
        rate = sc.nextFloat(

What is a DBMS?

• DBMS: Software used to store, manage, and retrieve data.
• Acts as a bridge between the user and the database.

Advantages of DBMS

• Reduces data redundancy
• Improves data consistency
• Provides data security
• Enables backup and recovery
• Facilitates data sharing

File System vs. DBMS

• File System: Lower security, higher redundancy.
• DBMS: High security, lower redundancy.

Three-Schema Architecture

1. External Level: User view.
2. Conceptual Level: Logical structure.
3. Internal Level: Physical storage.

Schema and Instance

• Schema: Structure of the database (rarely changes).
• Instance: Actual data at a specific moment (changes frequently).

Data Models

• Hierarchical
• Network
• Relational (most used)
• Object-oriented

Relational Model

• Data stored in tables (relations).

Key Terms

• Tuple:

Network Delay and Performance Metrics

Understanding the components of network delay is essential for optimizing data transmission:

• d-proc (Processing Delay): Checks for bit errors and determines the output link; typically less than a microsecond.
• d-queue (Queuing Delay): Time spent waiting at the output link for transmission, heavily dependent on network congestion.
• d-prop (Propagation Delay): Calculated as Link Length / (2 x 10⁸).

Key Variables: a = average packet arrival rate, L = packet length, R = link bandwidth.

DNS Record Types

The Domain Name System (DNS) uses Resource Records (RR) in the format: (name, value, type, ttl).

• Type A: Name is the hostname; value is the IP address.
• Type CNAME: Name is an alias for a canonical name; value is the actual

Introduction to the Operating System (OS)

An Operating System (OS) is the most crucial type of system software that acts as an intermediary between the computer hardware and the user or application programs. Simply put, it is the software layer that allows you to interact with the machine in a meaningful way. Without an OS, the computer hardware is just a collection of electronic components. The OS manages all the system's resources, making it convenient and efficient for users and applications to execute programs.

Functions of the Operating System

The OS performs several essential functions to ensure the smooth, efficient, and secure operation of a computer:

• Process Management (CPU Scheduling): The OS determines which running program (process)

Assembly Language Code Analysis and Solutions

Section 1: Instruction Correctness Check

.data

calculate WORD 100
wVal DWORD 2

Instructions:

1. mov bl, calculate
2. mov ax, wVal

Question 1: Are the above two instructions correct? If not, justify your claim. [2 marks]

Answer:

Both instructions are incorrect.

• For the mov operation, the operands must generally be of the same size.
• In instruction 1, bl is 8 bits (1 byte), but calculate is defined as a WORD (16 bits or 2 bytes). The operand sizes do not match.
• In instruction 2, ax is 16 bits (2 bytes), but wVal is defined as a DWORD (32 bits or 4 bytes). The operand sizes do not match.

Section 2: Loop Pseudo-code

Question 2: Write the pseudo-code for the loop that calculates the sum of the integers 3 + 2 + 1. [2 marks]