Introduction to Operating Systems, Computer Networks, and Database Systems
What is an Operating System?
An operating system (OS) is a software that acts as an intermediary between computer hardware and user applications. It manages computer hardware resources and provides common services for computer programs. Here are some key functions of an operating system:
Functions of an Operating System
- Process Management: The OS manages processes, which are programs in execution. It allocates resources, schedules tasks, and controls execution flow to ensure efficient utilization of
Cybersecurity Algorithms in Java: From Caesar Cipher to Firewall
1) Ceasar Cipher :
import java.
Util.*;
class substitutionTech {
private char[] alphaBets = “ABCDEFGHIJKLMNOPQRSTUVWXYZ”.ToCharArray();
private int key = 3;
private Scanner scanner;
substitutionTech() {
scanner = new Scanner(System.In);
askQuestion();
}
public void askQuestion() {
System.Out.
println(
“Operations:\n\tQ: Quite\n\tG: Get key\n\tS: Set new key\n\tE: Encrypt sting\n\tD: Decrypt string“);
loop:
SCADA Systems: An Overview
SCADA
Control via PC
The PC is being established in many fields (work, home, industry, etc.). Automated tasks that control and display were performed with PLC (programmable logic controllers or PLC) are being made with control systems based on PC using expansion cards or data acquisition.
Advantages:
- Data processing, visualization, networking.
Disadvantages:
- Real-Time, security, robustness.
As commonly used with PLCs, to the highest level, making monitoring and control tasks.
SCADA System
SCADA comes from
Read MoreJava Programming Examples
Str PA
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
class Str {
private final Supplier contents;
private final Function, String> log;
private Str(Supplier contents) {
this.contents = contents;
this.log = action -> {
String value = contents.get();
action.accept(“traced Str: ” + value);
return value;
};
}
private Str(
Supplier contents,
Function, String> log) {
this.contents = contents;
this.
Read MoreData Structure Algorithms: Hashtables, Lists, Trees, and Graphs
Hashtable Compression: Removing Duplicates
public int compress() {
Set<T> in = new HashSet<>();
int count = 0;
for (int i = 0; i < table.size(); i++) {
T current = table.get(i);
if (current != null) {
if (in.contains(current)) {
table.set(i, null);
count++;
size--;
} else {
in.add(current);
}
}
}
return count;
}
List Reversal
public void reverse(Understanding Functions and Events in JavaScript
Accumulator Concept
In programming, a counter, often denoted as ‘x’, is used to track the number of iterations in a loop. An accumulator (ACC) is a special variable that increases or decreases with variable values during program execution. For example, if we have a variable named ‘amount’ within a loop, each cycle of the loop can increase the ‘amount’ variable based on a value entered by the user.
Repetitive Structures: While and For Loops
Problems requiring repetition can be solved using ‘while’
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