Data Representation Unit 4 PDF

University of the Cordilleras College of Information Technology and Computer Science DATA REPRESENTATION UNIT 4 Data Representation Method by which computers store, process, and communicate information in a format that humans and computers can understand Data must be...

University of the Cordilleras College of Information Technology and Computer Science DATA REPRESENTATION UNIT 4 Data Representation Method by which computers store, process, and communicate information in a format that humans and computers can understand Data must be represented in a digital form (using binary), which allows for efficient processing and storage Why Do Computers Use Binary? Computers operate on electrical signals, which have two possible states: ON (1) and OFF (0). Binary representation (0 and 1) aligns well with these states, making it efficient and reliable. Each binary digit is called a bit. Units of Data Representation Bit: Smallest unit, representing either 0 or 1. Byte: 8 bits, representing 256 possible values. Word: Larger unit (typically 16, 32, or 64 bits) used in processing. *More bits per word allow for faster processing speeds in computers. Information Amount and Binary Combinations Information Amount refers to the number of bit combinations. The number of values doubles with each additional bit. Examples: 1 bit = 2 values (0, 1) 2 bits = 4 values (00, 01, 10, 11) 3 bits = 8 values, etc. Formula: With n bits, 2^n combinations are possible. Information Amount and Binary Combinations Information Amount refers to the number of bit combinations. The number of values doubles with each additional bit. Examples: 1 bit = 2 values (0, 1) 2 bits = 4 values (00, 01, 10, 11) 3 bits = 8 values, etc. Formula: With n bits, 2^n combinations are possible. Radix Conversion (Binary to Decimal) Conversion involves multiplying each digit by its place value. Example: Binary 1001101.101 in decimal. Radix Conversion (Decimal to Binary) Separate integer and fraction parts for conversion. Integer: Divide by 2 repeatedly until the quotient is 0. Fraction: Multiply by 2 until the fractional part is 0 or starts repeating. Example: Converting 77.625 to binary. Error in Data Representation Some decimal fractions do not have exact binary equivalents. Example: Converting 0.1 in decimal to binary results in a repeating fraction. 0.1 = 0.00011001100110011... This results in approximation errors, important in scientific computations. Analog Data Continuous data with an infinite range of values Ideal for representing natural signals Characteristics: Continuity, Infinite Range, Susceptible to Noise Ex: Sound Waves, Light Intensity, Temperature Changes Digital Data Discrete data represented in binary (0s and 1s) Characteristics: Finite Values, Discrete Steps, Less Prone to Noise Ex: Binary code, Digital Images, MP3 Music Files Nyquist Theorem It defines the minimum rate at which an analog signal should be sampled to accurately capture its information without distortion or loss. "To accurately capture all information in an analog signal, it must be sampled at a rate of at least twice its highest frequency." Nyquist Rate: Minimum sampling rate = 2 × highest frequency. Sampling Process of measuring the amplitude of an analog signal at regular intervals, creating a series of discrete data points. Aliasing Distortion caused by sampling below the Nyquist Rate. High-frequency components appear as lower frequencies. Analog to Digital Conversion or A/D Conversion (ADC) Process by which continuous analog signals are transformed into a digital form Breaks down an analog signal and reconstructing it as a series of discrete values allowing the digital representation of complex signals, enabling them to be processed, stored, and transmitted in computer systems Steps of ADC 1. Sampling Converts an analog signal into a series of discrete time points. For accurate digital representation, the sampling rate should be at least twice the highest frequency of the analog signal, as dictated by the Nyquist Theorem. 2. Quantization Maps the sampled amplitudes to a fixed set of values, effectively rounding them to the nearest level in a defined range. This step introduces quantization error, where slight inaccuracies may arise due to rounding. 3. Encoding Once quantized, each level is assigned a unique binary code, representing the signal in digital form. Encoding converts these quantized values into a sequence of bits that can be stored, processed, or transmitted digitally. Sound Processing Process that analog sound is handled as digital data The techniques of A/D conversion by which an analog signal is encoded into a digital signal include PCM (Pulse Code Modulation) Sound Processing * The sampled sampling values are rounded to the nearest integer numbers. Sound Processing * A quantized integer number is encoded by representing it as a binary number. (The number of bits used as a code is called the quantization bit rate.) Analog to Digital Conversion or A/D Conversion (ADC) Process by which continuous analog signals are transformed into a digital form Breaks down an analog signal and reconstructing it as a series of discrete values allowing the digital representation of complex signals, enabling them to be processed, stored, and transmitted in computer systems Sound File Formats MIDI (Musical Instruments Digital Interface) Electronic musical instrument and PC are connected and music data is exchanged. MP3 (MPEG1 Audio Layer3) It is a high-quality sound compression and decompression format using the sound technology of MPEG standardized by ISO, which is used in Internet music distribution and portable players. WAV (RIFF Waveform Audio Format) Mainly used in Windows systems. ADPCM (Adaptive Differential Pulse Code Modulation) Sound signal compression method in which the PCM technique is applied. WMA (Windows Media Audio) Streaming technique of music distribution that was developed by Microsoft. Still Image File Formats BMP (Bit MaP) Represents the characters and images as a set of dots. A flaw that exists is that the amount of information generally increases more than in other formats. TIFF (Tagged Image File Format) Enables handling of bit map images of various formats through the addition of tags JPEG (Joint Photographic Experts Group) Enables adjustment of the image quality and data amount by regulating the amount of compression. GIF (Graphic Interchange Format) Supports 256 colors. Although it is a lossless compression format, the amount of data is comparatively less, and it is also used in image processing on the WWW. Still Image File Formats PNG (Portable Network Graphics) Supports full color and is an expansion of GIF. It is a lossless compression format, and the amount of data is more than JPEG. Exif (Exchangeable Image File Format) It is a format that additional information (i.e., meta data), such as the photography time, is attached and saved in the image data taken by a digital camera. Moving Image File Formats MPEG (Moving Picture Experts Group) Standards are defined according to the quality of the image to be compressed. MPEG-1: Images that have a quality of video level MPEG-2: Television pictures and high-vision pictures MPEG-4: Assuming the use of cellular communication MPEG-7: Assuming the implementation of a high-speed search engine QuickTime Used in Apple’s “QuickTime.” JPEG images are played back continuously. VRML (Virtual Reality Modeling Language) It is a file format for displaying 3D graphic data as pictures. AVI (Audio Video Interleaving) Mainly used in Windows systems. It uses RIFF, a format of multimedia files.  University of the Cordilleras College of Information Technology and Computer Science PROJECT MANAGEMENT UNIT 5 Project A temporary endeavor with a unique purpose Finite in nature, with a clear start and end Carried out to accomplish specific goals and produce unique outcomes, often creating something new, improved, or customized Key Characteristics: 1. Temporary: Projects are not permanent activities; they have a defined beginning and end. 2. Unique Output: Each project yields unique results, whether a product, service, or process. 3. Goal-Oriented: Projects are driven by specific objectives, which determine the project’s direction and purpose. Features of a Project 1. Temporary: Projects are time-bound, with a specific start and end. This time limitation defines the scope of what can be achieved within a project. 2. Unique Output: Projects create unique outcomes, and no two projects are identical. Even if they follow similar processes, each project is adapted to meet unique goals. 3. Progressive Elaboration: As a project progresses, new information may emerge, refining the original goals and plans. This gradual refinement process is called progressive elaboration. 4. Constraints: Projects often face constraints such as limited resources (time, money, materials), scope (what needs to be achieved), and quality standards. 5. Resource and Quality Requirements: Projects demand careful allocation of resources to ensure the final deliverable meets specific quality expectations. Project Organizational Structures 1. Functional Organization: Structure: Departments are organized by functions (e.g., Marketing, IT, Finance) Project Role: Project work is assigned to functional departments, and project managers often have limited authority Advantages: High efficiency within specialized departments Disadvantages: Limited collaboration across departments and slower decision-making Project Organizational Structures 2. Matrix Organization: Structure: Combines functional and projectized structures, allowing team members to report to both a functional and project manager Types: Weak Matrix: Low authority for project managers Balanced Matrix: Shared authority Strong Matrix: High authority for project managers Advantages: Encourages resource sharing and collaboration Disadvantages: Dual reporting can create conflicts Project Organizational Structures 3. Projectized Organization: Structure: The entire organization is structured around projects. Project managers have full authority over resources and decision-making Advantages: Strong focus on project goals and fast decision-making Disadvantages: Limited stability for employees once the project ends Core Responsibilities of a Project Manager 1. Scope Management: Define and control what is included in the project 2. Schedule Management: Establish and manage the project timeline 3. Cost Management: Oversee the project budget and control expenses 4. Risk Management: Identify, assess, and mitigate potential risks 5. Quality Management: Ensure that deliverables meet the required standards Key Skills for Project Managers Problem-solving: Effectively address project challenges Communication: Facilitate clear communication with the team and stakeholders Negotiation: Resolve conflicts and secure project resources Leadership: Inspire and guide the team toward success Types of PMO 1. Supportive PMO: Provides templates, training, and best practices 2. Controlling PMO: Enforces compliance with standards and methodologies 3. Directive PMO: Directly manages projects, with high authority over project teams Project Life Cycle Process Groups 1. Initiating 2. Planning 3. Executing or Implementing 4. Controlling and Monitoring 5. Closing Initiating Key Activities: Develop Project Charter: The project charter formally authorizes the project, outlining the objectives, key stakeholders, budget, and timeline. Identify Stakeholders: Stakeholders (people or groups affected by or involved in the project) are identified and their needs and expectations are documented. Outputs: Project Charter: A document that provides an overview of the project’s purpose, objectives, high-level requirements, and major stakeholders. Stakeholder Register: A list of stakeholders, their roles, interests, and potential influence on the project. Planning Key Activities: Scope Management: Define the work required for the project, including deliverables and requirements. Time Management: Develop a project schedule, including milestones, deadlines, and dependencies. Cost Management: Estimate project costs and prepare a budget. Quality Management: Define quality standards and establish procedures for maintaining quality. Risk Management: Identify potential risks and plan responses to mitigate them. Resource Management: Plan for human, physical, and financial resources. Communication Management: Develop a communication plan to ensure effective information flow. Planning Outputs: Project Management Plan: A comprehensive document that outlines all aspects of the project, including scope, schedule, cost, quality, resources, and risk management. Work Breakdown Structure (WBS): A hierarchical decomposition of the total scope of work into manageable sections. Baseline Plans: Baselines for scope, schedule, and cost are established, serving as references for monitoring project performance. Executing (or Implementing) Key Activities: Resource Allocation: Assign tasks and responsibilities to team members. Team Development: Build team cohesion and ensure members are motivated. Communication: Facilitate ongoing communication with stakeholders, providing updates on progress. Quality Assurance: Monitor work processes to ensure they align with quality standards. Outputs: Project Deliverables: The tangible or intangible products created by the project. Performance Reports: Documentation of the project’s progress, achievements, and challenges. Change Requests: Requests for changes to the project scope, schedule, or budget, which are evaluated and approved or rejected. Controlling and Monitoring Key Activities: Resource Allocation: Assign tasks and responsibilities to team members. Team Development: Build team cohesion and ensure members are motivated. Communication: Facilitate ongoing communication with stakeholders, providing updates on progress. Quality Assurance: Monitor work processes to ensure they align with quality standards. Outputs: Status Reports: Regular reports on project progress, highlighting performance against the baseline. Updated Project Plans: Revisions to the project management plan to reflect any approved changes. Risk and Issue Logs: Documents that track identified risks and any issues encountered. Closing Key Activities: Final Deliverable Handover: Transfer the finished product or service to the client or end user. Project Closure Documentation: Prepare documentation that officially closes the project, detailing outcomes, achievements, and lessons learned. Stakeholder Feedback: Collect feedback from stakeholders to evaluate the project’s success and identify areas for improvement. Outputs: Final Project Report: A summary of the project’s objectives, outcomes, and performance. Lessons Learned Document: Documentation of insights gained throughout the project, useful for future projects. Project Closure Documents: Formal documents that confirm the project is complete and can be archived. Project Management Methodology PMBOK (Project Management Body of Knowledge) Provides a structured framework applicable to projects of any size or complexity. Globally recognized certification (PMP) enhances project management credibility. ISO 21500 Focuses on achieving organizational alignment through project activities. Provides a globally accepted standard, enhancing project comparability and quality. Agile Methodology Emphasizes flexibility, iterative progress, and customer collaboration. Agile Methodology 1. Scrum: Scrum organizes work into Sprints, short cycles (usually 2-4 weeks) that produce a potentially shippable product increment. 2. Kanban: Kanban focuses on visualizing workflow and limiting work-in-progress to improve efficiency. Kanban Board: A tool with columns representing different stages of work 3. Extreme Programming (XP): XP emphasizes technical practices such as test-driven development, pair programming, and continuous integration. Designed to enhance software quality and responsiveness to customer requirements.  University of the Cordilleras College of Information Technology and Computer Science LANGUAGES UNIT 6 Compiled vs. Interpreted Languages Compiled Languages: Process: Source code is translated into machine code by a compiler before execution. Examples: C, C++, Go. Interpreted Languages: Process: Source code is executed line-by-line by an interpreter at runtime. Examples: Python, Ruby, JavaScript. Hybrid Approaches: Just-In-Time (JIT) Compilation: Combines both compilation and interpretation, compiling code on the fly during execution. Examples: Java (compiles to bytecode, then interpreted by the JVM),.NET languages.