Unit 1: Introduction to Systems — Long Questions

A system is described by its objectives components, communication among components and environment in which it works. The components of a system communicate with each other to achieve the system's objective in an environment. Systems can be simple, like a thermostat, or complex, like the human body or a computer network.

Systems can be broadly categorized into two types, namely natural and artificial systems.

Natural Systems
Natural systems are those that exist in nature and operate independently of human involvement. They are governed by natural laws and process. Following are the examples of some natural systems that exist in nature.

1. Physical Systems
Physical systems are composed of physical components and governed by the laws of physics. They include things ranging from sub atomic particles, atoms, planets, stars, galaxies and customs. Physical systems, like any kind of matter, emerge from the interactions of electrons, protons, neutrons and sub-atomic particles which are governed by electric and atomic forces.

2. Chemical Systems
Chemical systems involve substances and their interactions, transformations, and reactions. They are governed by the laws of chemistry. For example, a chemical system like water (H₂O) is formed when hydrogen atoms bond with oxygen atoms, following chemical rules and reactions.

3. Biological Systems
Biological systems consist of living organisms and their interactions. They are governed by biological processes such as growth, reproduction, and metabolism. Biological systems emerge from chemical systems when molecules interact in complex ways to form living cells, which then organize into tissues, organs, and organisms.

4. Psychological systems
Psychological systems involve the mind and behavior. They include thoughts, emotions, and mental processes, governed by the principles of Psychology. Psychological systems emerge from biological systems when the brain's physical and chemical processes give rise to thoughts, emotions, and behaviors.

Artificial Systems are created and developed by people so that they may fulfill certain functions or address certain issues. These systems can be as small as a wheel or as large as the United Nations. Artificial systems are a vital part of the contemporary society because they reinforce productivity, solve complex problems, and improve people's well-being. There are different types of artificial systems, some of which are described below:

Knowledge Systems
A knowledge system is unique because it is developed to capture, process, facilitate, store, retrieve and manage information.

• Mathematics: Mathematics is field of knowledge which is studied to focus problems connected to numbers, their amounts, forms, structures and patterns.

• Logic: Logic is a theoretical model consisting of concepts and strategies on identifying and assessing rationale. That is why it is based on all logical thinking processes and practice of critical analysis.

• Databases: A database system can best be described as software for managing data, particularly to enable easy retrieval, management, and updating of data. Some of the examples are relational database management system like MySQL while others are NoSQL database management system like MongoDB.

• Information Management Systems: These are specific applications developed with the purpose of capturing archiving, organizing and disseminating data.

1. Engineering Systems
Products developed by engineers are complex frameworks or devices that apply engineering concepts to perform certain tasks or solve technical challenges. These are some examples of how engineers of various types develop systems according to their own special knowledge and perspective, given to them through their original visions and approaches.

• Civil Engineering Systems: Concentration on developments such as constructing houses, roads, bridges and even maintaining these structures. For instance, a structure used to provide a passage over water, valleys or roads is termed a bridge.

• Mechanical Engineering Systems: Engage in planning and creating devices that make a utilization of forces from outside to accomplish work. For instance, a robotic arm applied in assembly line for packaging of products in factories.

• Chemical Engineering Systems: Focuses on converting raw materials into useful products through chemical processes, considering internal molecular interactions. For example, a water treatment plant that purifies water using chemical processes like coagulation and filtration.

• Electrical Engineering Systems: Involves the study and application of electricity, electronics and electromagnetism to develop electrical systems. For example, a home automation system that controls lighting, heating and security using a smartphone app.

• Software Engineering Systems: Is the process of designing, developing and maintaining software to perform certain tasks eradicating errors. For instance, an online tool assisting a library in tracking books, users as well as stock in their possession.

2. Social System
Social systems refer to structured frameworks established by individuals to effectively handle social interactions, organizational governance, and communal endeavors. The basic goal of these systems is to maintain in order, provide services and facilitate social connections.

• Academic institutions: These are the entities that provide educational services to students. Schools, colleges and universities are examples of educational institutions that provide instruction via the use of administrative, teaching, and support staff.

• Governments: Organizational institutions that wield authority and control over a community or country. Examples include democratic systems, where representatives are elected and authoritarian regimes, where power is centralized.

• Organizations: These are the entities formed to achieve specific goals and are often structured hierarchically with well-defined roles and responsibilities. Examples include corporations like Apple and non-profit organizations such as the Abdul Sattar Edhi Foundation.

Knowledge is our understanding of various systems in the universe around and within us. Science is a systematic way to validate this understanding. Science can be divided into two main types: natural science. In natural science, scientist study existing natural systems to understand their workings. While in design science scientist create new systems to solve problems or achieve specific goals.

1. Natural science is meant to uncover the objectivity and functionality of natural systems in the natural world. Its nature is descriptive, meaning that the scientists seeks to understand and describe natural phenomena.

2. Design Science is focused on designing and creating artifacts (tools, systems, methods) to achieve specific goals. The nature of design science is prescriptive, meaning that it aims to prescribe and create artificial systems. To achieve this design science researchers, follow the regulative cycle.

Examples

• Natural Science: Studying the ecosystem of a forest to understand how different species interact (descriptive).
• Design Science: Developing a new software system to manage forest data and improve conservation efforts.

3. Computer Science
Computer science is the study of how computers work, including at what they can do and their limitations. To understand computer science, we use methods of both design science and natural science.

• Natural science of computer science Natural science of computer science focuses on finding the basic rules that control how computer systems work. This involves the study of various algorithms and their characteristics.

• Study of Algorithms Researchers analyze existing an algorithm to understand their efficiency and limitations. For example, studying different sorting algorithms and their characteristics which arrange given data in an order.

Design Science of Computer Science

• Development of new software tools Researchers create new tools or applications to solve specific problems.

For example Designing a new programming language that makes it easier for developers to write secure computer programs.

• Improvement of computer system Researcher work on enhancing existing systems to perform better. For example, creating a more efficient database management system that can handle larger amounts of data faster and with fewer errors.

A computer is a complex system designed to process data and perform tasks according to a set of instructions.

Objectives
The main objective of a computer is to perform computations, process data, and execute different tasks efficiently. For example, a personal computer's objective is to run software applications such as word processors, web browsers and games through various computational processes.

Components
A computer is composed of many essential components that operate in conjunction. These components include:

Interface Components Interface components refer to the fundamental parts of a computer system, including input devices such as the keyboard and mouse, which allow users to interact with the computer.
Computer output devices, such as monitors and printers, are used to presents or generate results from the computer's operations.

Processing Components

• The processing components of a computer consist of the CPU, which acts as the Central Processing Unit responsible for computations and executing command.
• Random Access Memory (RAM) is a transient storage that stores data and instructions for the CPU, whereas Storage (Hard Drive or SSD) is a permanent storage for data and software needed for future processing.
• The operating system is responsible for receiving information from interface components and determining the appropriate actions to take.
• Application software refers to programs that are executed by the operating system when required to perform one or more specified tasks.

Communication Components
Communication components in a computer refer to the physical elements that provide communication between different components of the computer.

• In a computer, the motherboard serves as the primary circuit board that interconnects all components by using cables and circuits.
• A system bus is a collection of electrically conductive cables that transmit data between the CPU and all other interconnected components. There are three distinct types of buses: data bus, address bus, and control bus.

The components of a computer interact with each other to perform tasks. For example, when you open a file using your mouse or keyboard, several components of your computer interact seamlessly to make this action happen. Here's a step-by-step explanation of the process.

1. User Action or input: You double-click on a file icon using your mouse or press a key combination to open a file. For example, you double-click on a document named "report.docx" on your desktop.

2. Input Device: The mouse or keyboard sends a signal to the computer indicating that you want to open the file. For example, the mouse sends sensory input to the computer's operating system through the USB (Universal Serial Bus) connection.

1. Environment
The computer system environment includes any external devices that interact with the computer.
For example.

• Power Supply: Provides electrical power to allow the computer to work.
• Network: Connects the computer to other systems and the internet.
• Peripherals: Include printers, scanners and external discs that expand the computer's capabilities.

2. Interaction with the environment
User Input: A user types on the keyboard and the computer processes the input to display text on the screen.
Network Communication: The computer sends and receives data over the internet to browse websites or download files.
Power Supply: The computer relies on a stable power supply to function correctly.

The Von Neumann architecture is a computer paradigm that delineates a system in which the hardware of the computer has four primary components: the memory, the Central Processing Unit (CPU), input mechanisms, and output mechanisms. This model is called the John Von Neumann model, the Neumann model named in honor of the mathematician and physicist who contributed to its development during the 1940s.

Components
Now we will look at brief overview of the key parts that constitute the architecture of the Von Neumann computer.

1. Memory: Contain both input data and the instructions (program) required for CPU processing. For instance, consider the RAM of your computer, when a program starts it is loaded into RAM to enable faster execution compared to when it runs from the hard disk.

2. Central Processing Unit (CPU): Performs addition and subtraction and executes commands provided by the memory. The system has two main components: The Arithmetic Logic Unit (ALU) performs mathematical computations and logical operations.
A Control Unit (CU) is a peripheral that governs the activities of the CPU by instructing the ALU and memory to execute tasks according to the program instruction. It ensures the proper and timely execution of duties by all the other components.

When doing the calculation 2 + 2 on a calculator application, the Arithmetic Logic Unit (ALU) handles the numerical values while the Control Unit (CU) supervises the whole procedure.

3. Input devices: Enable users to input data and instructions into the computer system. Illustrative examples include keyboard, mouse, and microphone. Entering text on the keyboard transmits data to the CPU for subsequent processing.

4. Output devices: Present or communicate the outcomes of the tasks executed by the computer. Consider, for instance, a monitor and printer, upon completion of data processing, the CPU transmits the outcomes to the monitor for visual display.

A system bus is a communication mechanism that facilitates the movement of data between components inside a computational system. It comprises:
Data Bus: Transports data.
Address Bus: Maintains data destination information.
Control Bus: Transports control electrical signals.

The Von Neumann architecture encompasses three essential stages for a CPU to carry out instructions, namely retrieval, interpretations, execution, and storage to demonstrate this procedure, we will use the example two-digit addition with basic calculator application.

1. Fetching
Description: The central processing unit retrieves an instruction from the computer's memory. This instruction specifies the operation to be executed by the CPU.
Hardware Components: Memory, CPU (Program Counter (PC), Instruction Register (IR)
Specification: The Program Counter (PC) stores the memory address of the subsequent instruction. Once the address is stored in memory, the instruction located at that location is retrieved and placed into the Instruction Register (IR).

2. Decoding
In order to determine the necessary action, the Control Unit (CU) decodes the instruction.
Comprising components: Control Unit (CU).
Detail: The Control Unit (CU) decodes the opcode (operation code) of the instruction and determines the required procedures and data.

3. Execution
Description: The CPU processes the instruction. When the instruction involves a computation, it is executed by the Arithmetic Logic Unit (ALU). Any task that requires transferring data between several locations is managed by the CU.
Involved Components: ALU, CU.
Detail: The Arithmetic and Logic Unit (ALU) carries out mathematical and logical calculations, while he Control Unit (CU) handles data transmission activities.

4. Storing:
Description: The outcome of the computation is either returned to memory or sent to an output device.
Involved Components: Memory and output Device.
Specification: The outcome is either stored in a designated memory location or sent to an output device, such as a display.

Following are the key characteristics of the Von Neumann computer architecture:

1. Single Memory Store: Both program instructions and data are stored in the same memory space. For example, in a computer game, both the game's code and the data' (like scores and player position) are Stored in the same RAM.

2. Sequential Execution: Instructions are processed one after another in a sequence. For example, when your computer runs a program, it follows the steps one by one in the order they are written.

3. Stored Program Concept: Programs are stored in memory and can be changed by the computer. For example, when you update a software program, the new instruction replaces the old one in memory.

Advantages and Disadvantages
The advantages and disadvantages of Von Neumann computer architecture are discussed here.

Advantages

• Simplified Design: By combining instructions and data into a single memory area, architecture is simplified.
• Flexibility: Programs can be easily changed by changing memory contents.

Disadvantages

• The Von Neumann bottleneck occurs when a single memory area limits the CPU's ability to fetch instructions and data quickly.
• Security Risks: Having data and instructions stored in the same area poses a problem where one program can alter another's instructions in a manner that is security risk. The Von Neumann architecture is key important aspect of the design and structure of many computers, serving as a central model on how they operate. However, this model has been essential in the evolution of computing technology, despite its limitation.

A computer system is a structured set of hardware and software components specifically designed for data processing and the performance of various operations. These systems can range from simple technological tools, such as calculators used for performing mathematical calculations to complex network of linked computers.

• Hardware of a computer system refers to the tangible components of the system. These include the Central Processing Unit (CPU), Random Access Memory (RAM), storage devices, and input and output devices.

• Software refers to a collection of instructions that dictate the requirements and actions that hardware must do. There exist two primary categories. System software and application software. System Software comprises the Operating System (OS) and utility applications responsible for managing the computer's resources such as Windows, macOS, and Linux distributions. Application software refers to software applications that are specifically developed to carry out certain functions for the user, such as word processors web browsers, and games.

• Electricity: Electricity is the power source that enables the hardware components to function. Without electricity the hardware components cannot function and the computing system will not operate.

1. Types of computing Systems
Computing systems come in various types some of these include the followings

• Computer
• Software Systems
• Computer Networks
• Internet

2. Computer Network Systems
A computer network system connects multiple computers and devices, enabling the efficient exchange of resources and information.

3. Objectives

• Resource Sharing: Allow multiple users to share resources like files, printers, and internet access within an office or other settings.
• Communication: Enable efficient communication between devices and users.
• Data Management Facilitate easy data management and collaboration.

4. Components
Routers: Routers are devices that transmit data packets between their networks
Switches connect devices in a network and facilitate communication.
Network Cables: A physical medium for data transfer.
Network Software
Protocols: Rules and conventions for data exchange such as TCP/IP.
Network Operating Systems: Software that manages network resources, such as Windows Server.

The internet is a vast and complex system designed to connect multiple networks worldwide, include private public, academic, business, and government networks. Its primary objective is to facilitate communication and data exchange between computers and users globally

Internet Protocols

• TCP/IP (Transmission Control Protocol/ Internet Protocol): The core protocols that govern data transmission over the internet.
• User Datagram Protocol (UDP): Faster but less reliable.
• File Transfer Protocol (FTP): Used for Transforming files between computers.
• Post Office Protocol (POP): Used for retrieving emails from server/network.

Interaction among Components The components of the internet interact with each other to perform different tasks. For example, when a user requests a web page through a web browser, several components of the internet work together to display its contents on the user's screen.

Environment
The internet operates in a diverse and dynamic environment, connecting various types of networks across different locations including homes, offices, data centers, and mobile networks. This environment influences the design security, and performance of the internet.