9608_s19_qp_11
A paper of Computer Science, 9608
Questions:
6
Year:
2019
Paper:
1
Variant:
1
Login to start this paper & get access to powerful tools
1
Devices connected to the Internet have IP (Internet Protocol) addresses. Three IPv4 addresses are given. Circle either Valid or Invalid to indicate whether each address is valid or invalid. Explain your decision. Address 1: 3A.21.2H.1 Valid / Invalid Explanation Address 2: 299.53.2.2 Valid / Invalid Explanation Address 3: 192.2.1.0 Valid / Invalid Explanation A website can be accessed using either the Uniform Resource Locator (URL) or the IP address. Describe how a URL is converted into its matching IP address. People use the Internet to stream media. Complete the following statements by filling in the names of the missing methods of bit streaming. bit streaming is used when watching a live stream of events that are currently taking place. The event is captured live with a video camera connected to a computer, and it cannot be paused or rewound. bit streaming is used when watching an event that has taken place in the past. Existing media are encoded to bit streaming format and uploaded to a server. It can be paused and rewound. A recording of a concert is stored as a file. The file is compressed using lossy compression before it is streamed to users. State why this file needs to be compressed. Define the term lossy compression. The file could be compressed using lossless compression. Explain why lossy compression is a more appropriate compression technique than lossless for this file.
1. Theory Fundamentals  →  1.2. Communication and Internet technologies
Open
2
A software company produces software and distributes it under different software licences. Four descriptions of software licences are given. Write the type of software licence that best fits each description. Use a different type of licence for each description. 1. The software can be legally used, only after a fee has been paid. Licence type 2. The source code comes with the software. If the software is modified, the edited source code must be released under the same conditions as the original software. Licence type 3. The software is free for a trial period and then a fee is requested, or expected, if the user wants to continue to use the software. Licence type 4. The source code comes with the software. The software is free to be downloaded, edited, and distributed, possibly without restriction. Licence type The software company stores information about customers and the software licences they have purchased. The company considers a file-based approach for the storage and retrieval of data. Give three limitations of a file-based approach to store the data. The software company decides to use a database to overcome the limitations of a file-based system. Some of these limitations are addressed through the logical schema. Name and describe two levels of the schema of a database. Name 1 Description Name 2 Description The database has the following tables: CUSTOMER(CustomerID, CompanyName) SOFTWARE(SoftwareID, SoftwareName, OperatingSystem, Description) LICENCE( LicenceID, CustomerID, SoftwareID, DateOfPurchase, LicenceType, Cost, ExpiryDate) Identify the type of relationship that exists between the tables CUSTOMER and LICENCE. Describe how the relationship is created between the tables CUSTOMER and LICENCE. The company needs a list of all software licences that have an expiry date on or before 31/12/2019. Write an SQL query to return the fields CustomerID, SoftwareID, LicenceType, Cost and ExpiryDate for all licences that expire on, or before 31/12/2019. Group the output by CustomerID, and in ascending order of cost.
1. Theory Fundamentals  →  1.8. Database and data modelling
1. Theory Fundamentals  →  1.7. Ethics and ownership
Open
3
Kimmy has written a program in a high-level language. Kimmy has used library routines in the program. Describe two advantages of using library routines in the program. Describe what is meant by a Dynamic Link Library (DLL). Three translators are compilers, interpreters, and assemblers. State one benefit of Kimmy using an interpreter during the development of the program. State three benefits of Kimmy using a compiler when the program is complete.
1. Theory Fundamentals  →  1.5. System software
Open
4
A software developer works in a team for a large software development company. Two principles of the ACM/IEEE Software Engineering Code of Ethics are: • developers must act consistently with the public interest • developers must act in the best interest of their client and employer. Name and describe three other principles in the ACM/IEEE Software Engineering Code of Ethics. Principle 1 Description Principle 2 Description Principle 3 Description The software development company uses data backup and disk-mirroring to keep their data secure. Explain how data backup and disk-mirroring allow the company to recover from data loss. Data backup Disk-mirroring
1. Theory Fundamentals  →  1.7. Ethics and ownership
Open
5
A simple program written in assembly language is translated using a two-pass assembler. The table contains some of the tasks performed by a two-pass assembler. Tick (✓) one box in each row to indicate whether the task is performed at the first or second pass. The first row has been completed for you. Task First pass Second pass Creation of symbol table ✓ Expansion of macros Generation of object code Removal of comments The processor’s instruction set can be grouped according to their function. For example, one group is modes of addressing. Identify two other groups of instructions. The table shows assembly language instructions for a processor which has one general purpose register, the Accumulator (ACC), and an Index Register (. Instruction Explanation Op code Operand LDM #n Immediate addressing. Load the denary number n to ACC. LDD Direct addressing. Load the contents of the location at the given address to ACC. LDX Indexed addressing. Form the address from + the contents of the Index Register. Copy the contents of this calculated address to ACC. LDR #n Immediate addressing. Load the denary number n to IX. STO Store contents of ACC at the given address. ADD Add the contents of the given address to ACC. INC Add 1 to the contents of the register (ACC or . CMP #n Compare contents of ACC with denary number n. JPE Following a compare instruction, jump to if the compare was True. JPN Following a compare instruction, jump to if the compare was False. JMP Jump to the given address. OUT Output to screen the character whose ASCII value is stored in ACC. END Return control to the operating system. The current contents of the main memory, Index Register (and selected values from the ASCII character set are: Address Instruction LDM #0 STO 300 CMP #0 JPE 28 LDX 100 ADD 301 OUT JMP 30 LDX 100 OUT LDD 300 INC ACC STO 300 INC IX CMP #2 JPN 22 END … … IX ASCII code table (Selected codes only) ASCII Code Character A B C D E a b c d e
1. Theory Fundamentals  →  1.4. Processor fundamentals
Open
6
A student records a video using a digital camera. The recording uses interlaced encoding. Describe interlaced encoding. State one benefit of using interlaced encoding compared to progressive encoding. A video can be compressed using spatial redundancy or temporal redundancy. Explain how temporal redundancy compresses a video. A sound track is recorded for the video. Describe how a computer encodes the sound track. Explain how the sampling rate and sampling resolution affect the file size of the sound track. Sampling rate Sampling resolution
1. Theory Fundamentals  →  1.1. Information representation
Open