Introduction to Computer Science Flashcards

Question

How does TCP/IP error detection work?

Answer 1

TCP/IP divides data into pieces to be sent over a network into segments or datagrams. These segments have a “header” at the beginning which defines the sending and receiving hosts, transmission settings, and also a 16-bit checksum to verify the data. The maximum size of this segment is ~65kb. When each segment arrives at the destination computer it is checked against the checksum value; if the values don’t match, a retransmit request is sent to the source computer. TCP/IP also checks for transmission errors on other levels. The receiving computer must also send an acknowledgement (ACK) for each datagram received. This is accomplished by giving each datagram a sequence number in the header. The recipient machine sends an ACK for each sequence number—if one of the numbers is not acknowledged after a certain period of time, the source computer will retransmit. TCP/IP will also detect broken routes over the network and re-route to new ones. This is one reason why TCP/IP has been used for decades on the internet: it is fault-tolerant. Part of the network can stop working without taking the entire network offline.

Answer 2

An oval, which is used at the beginning of a flowchart and at all the endings.

Answer 3

Rectangle. Used for data calculation or filtering.

Answer 4

A diamond. There are multiple pathways to take.

Answer 5

Parallelogram.

Answer 6

Arrays that contain other arrays. For every dimension, complexity is raised by an exponent.

Answer 7

An international encoding standard.

Answer 8

Since each letter and symbol has a binary value attached to it, that value can be used to sort.

Answer 9

A simple but inefficient sorting algorithm which iterates all elements multiple times, comparing contiguous elements and swapping them if needed according to the specified criterion. It has a worst-case complexity of O(n^2).

Answer 10

Binary inserƟon sort is a sorƟng algorithm that uses the same method we used for a binary search—by spliƫng the data in half repeatedly. To sort the data, it builds a new output list and takes items from the input list. The input list are items yet to be sorted, and the output are the ones already sorted. For inserƟng an element from the input list in the output list the data in the output list is spliƩed in half repeatedly unƟl the correct posiƟon of the new element is found.

Answer 11

It works by selecting a 'pivot' element from the array and partitioning the other elements into two sub-arrays, according to whether they are less than or greater than the pivot. The sub-arrays are then sorted recursively. This can be done in-place, requiring small additional amounts of memory to perform the sorting. Its average complexity is O(n*log(n)).

Answer 12

Binary search is a search algorithm that searches for data in a sorted list. It works by dividing the list into two halves, and then repeaƟng this process on each of the halves unƟl it reaches the desired data. The algorithm can be used to find an element in a sorted array.

Answer 13

Jump search is a search algorithm that uses a jump size to find the target element in an ordered list. The jump size is the number of elements that are skipped over between each comparison. Let’s say the book is 2,500 pages long. We calculate the square root of n, the number of pages, which gives us 50, which we will use for the jump size, or m. Ken will first jump to page 50 and see if Josh is higher or lower, then keep jumping unƟl he is past Josh. Then, he will go back to the previous jump and do a linear search (page by page) on the next 50 pages to find him.

Answer 14

The “Big O” function demonstrates the mathematical complexity of an algorithm, which is based on the data size of “n” elements.

Answer 15

This depends on the used language or underlying hardware architecture but typically, int uses 32 bytes and char uses 1 byte.

Answer 16

Propositional logic takes the concept of human statements and represents them as a formal equation. These logic equations can be used to evaluate the truth or falsity of claims made, or propositions.

Answer 17

Conjuctive normal form: a conjunction of several disjunctions. Disjunctive normal form: a disjunction of several conjunctions.

Answer 18

The Arithmetic and Logic Unit performs arithmetic calculations and logic operations such as OR and AND.

Answer 19

PC, MAR, MDR, AC, CIR

Answer 20

A bus is a connection used for data transfer, it's what CPUs use for input and output. There are 3 main ones: Address Bus, Control bus (used to send and receive status from devices), Data bus (to send an receive data such as arithmetic operations). In some designs, these three are merged into a system bus.

Answer 21

In the Von Neumann architecture, each byte of memory has a unique binary address. The number of bits used for adressing will identify the number of bytes available.

Answer 22

Since data and instructions are on the same memory bus, reading large volumes of data may cause the CPU to wait for many cycles to load the next instruction.

Answer 23

Input and output devices on a computer are typically assigned a binary “channel code” for the CPU; that means when a CPU receives this code it will be followed by a status message from that device. The CPU can also use this code to send information back to the device. This information flows along the control bus. Control codes for a device can include things like ready, busy, error, and request for input or output. Aside from the control bus, devices can also use the data bus to send data and the address bus to point to a specific memory address that may be read from or written to.

Answer 24

A word is the standard data size used by a processor. A 64-bit system uses 64-bit words; registers have this size.

Answer 25

1) Provide a user interface 2) Control the hardware 3) Run applications

Answer 26

A group of servers that share the workload for a certain task.

Answer 27

FLOPS (floating point operations per second). gigaFLOP = 1 billion calcs per second

Answer 28

A wide access network is a network of interconnected LANs. The internet is the largest WAN.

Answer 29

Consists of UTP (UNSHIELDED twisted pair cable) of various categories. Bps = Bytes per second, bps = bits per second. Category 6 UTP cable allows for up to 10gbps speeds.

Answer 30

A hub is the simplest network device, taking a signal from one cable and splitting out over several ones. Each split signal is called a "port". The ports can also communicate with the larger network through the uplink connection.

Answer 31

A unit of data transmitted over a network. A frame has a "from" and "to" MAC addresses.

Answer 32

A hub with basic filtering capabilities.

Answer 33

A unit of data transmitted over a network that is identified by an IP address, instead of a hardware address like a frame.

Answer 34

The most intelligent of the 3 connecting devices. It can filter data, including blocking data that does not belong to a network (firewall).

Answer 35

Ring: devices are connected together in a ring, and each device needs to check data to see if it needs to pass it to the next device. This design has fallen out of use for not being fault-tolerant. Mesh: all devices are connected to each other, which makes it fault-tolerant because there are multiple paths to each node. The inconvenient physical arrangement which required a lot of cable made it fall out of use. Star: the most widely used topology nowadays. Devices are connected to a central node which has the role of sending data to each outer node. It is fault-tolerant to a point but if the central node fails, the network will not function. Bus: this requires all devices to be connected to a bus, and if the connection fails anywhere, the entire network fails, making it not fault-tolerant. Data can travel up and down the data bus. Hybrid: any topology that connects multiple topologies is called a hybrid. For example, multiple star networks connecting through a bus network backbone.

Answer 36

The core of a network that connects the main parts together. It can also connect multiple networks.

Answer 37

Data in 2.4 can travel farther and through obstacles better than 5, but 5 can carry more data. 802.11ac is currently the fastest wireless protocol and is backwards-compatible with older devices.

Answer 38

Application Layer: interface exposed to user and applications to make network requests to the OS. Presentation Layer: formats data and provides encryption. Session Layer: maintains connections via ports. Transport Layer: Handles transmission protocols and settings, handles error checking and breaks down the data in chunks that are sent out separately. Network Layer: Routes data to destination through the physical route of the packets. This layer is handled by the router; in TCP/IP, this is where the IP address is used. Data in this level is organized in packets. Data Link Layer: Converts electrical signals into data; this is where the MAC address is used. Physical Layer: Consists of the electrical signals sent over the network and the physical devices that interact with them. Collision detection occurs in this layer.

Answer 39

Transmission Control Protocol / Internet Protocol is a suite of communication protocols to interconnect network devices. This model is divided into the following layers: Application: equivalent to OSI's Application, Presentation and Session layers. Transport: similar to OSI's transport layer. TCP is used here. Internet: equivalent to OSI's network layer. IP is used here. Network Access: equivalent to OSI's Data Link and Physical layers.

Answer 40

This is the unique address of a network device; there cannot be a duplicate on the same network. It is divided into a network ID and a host ID.

Answer 41

This is a binary sequence that identifies which parts of the address are the network ID and host IDs. In IPv6, this is called a prefix.

Answer 42

This is the network device that is used to access an external network. It is typically a router.

Answer 43

TCP/IP checks that all packets are received and looks for alternative paths to deliver the data in case a node along the way stops working.

Answer 44

A chip that used to contain all BIOS configuration but is now mainly used to preserve the system clock.

Answer 45

The Basic Input/Output System handles hardware requests from the operating system and drivers. It identifies connected hardware components and when booting up a computer, it looks for an installed operating system and starts it.

Answer 46

FAT is a filesystem that works by dividing a disk into clusters and stores the contents of the clusters in a File Allocation Table.

Answer 47

Projection of revenue predictions, hiring needs

Answer 48

Focuses on data of the whole company such as market research data, performance analysis.

Answer 49

High-performance data analysis system. Used for sales figures, product comparisons, creating reports.

Answer 50

It is a specific-purpose system that performs a primary task, such as medical equipment, fire alarms, washing machines, etc.

Answer 51

A microcontroller is a computer chip with a processor, RAM and i/o built in. The i/o travels through specific pins on the chip. These can receive and send data to USB ports and Ethernet. They are an entire computer on a chip.

Answer 52

APLADESIDEVTESDE Analyze requirements: create a requirements document, organizing the main ideas behind the proposal. Planning: determine feasibility, assign teams. Design: blueprint for development. Development Testing Deployment/maintenance: release and shipping updates to address bugs in the software.

Answer 53

REQDESIMVERMA Requirements Design Implementation Verification Maintenance

Answer 54

Coding, design, requirements and testing all begin simultaneously with little planning. It is risky but may lead to the quickest release of software.

Answer 55

Decimal to binary: Keep on dividing the decimal number by 2 until the result of the division operation is 0 while recording the remainder. The first digit of the binary number is the remainder of the division operation that resulted in 0. The last digit of the binary number is the remainder of the first division operation. The rest in reverse order is the binary number.

Answer 56

The ALU and the control unit are components of the CPU. The control unit is responsible for the operation of the ALU and communicaƟon with the input and output devices. It interprets processor instructions and carries them out.

Answer 57

A statement is a way of expressing a proposition; some statements can be worded in different ways while having the same underlying proposition.

Answer 58

SOCIETY, !HARM, HONESTY, CREATIVITY, CONFIDENTIALITY, PRIVACY

Answer 59

Dynamic Host Configuration Protocol (DHCP) is a protocol used to assign IP addresses and other network configuraƟon parameters to each device on a network so that the devices can communicate with each other.

Answer 60

Ethernet is a set of standards (defined by IEEE 802.3) used for LANs and WANs.

Answer 61

Input and output system is a system that allows the user to communicate with the computer hardware.

Answer 62

The CPU cache is a small memory that is placed on the CPU chip itself. It is a memory for data and instrucƟons that the processor can access very quickly. This allows to speed up memory access Ɵmes. There are different levels of cache: some processors have three levels labelled L3, L2, and L1, each smaller and with a faster access Ɵme. This provides a way to avoid memory boƩlenecks as the CPU does not always have to make a request of system RAM; a small amount of currently used data is located in the cache.

Answer 63

The von Neumann architecture is a reference model for the architecture of a computer. It consists of - a CPU, - a memory that holds both computer program instrucƟons and data, - an input system, - an output system. The CPU consist of an ALU, a control unit and registers, which contain a fixed number of bits. These registers can contain data or instrucƟons that have been read from memory. Besides the processor and memory, there also should be some type of input (entering data) and output system (outpuƫng data) to be able to communicate with other devices or a human being.

Answer 64

The correctness of an algorithm is an important requirement for algorithm development. Any algorithm that is used must be mathemaƟcally correct. An algorithm is totally correct if it receives valid input, terminates, and always returns the correct output. We can prove this by formal reasoning or mathemaƟcally, for instance, with a proof by inducƟon.

Answer 65

Protocol, computer name, domain name, directory, filename.

Answer 66

All informaƟon is stored in binary format in computers. If you want to store alphabeƟcal leƩers, you can represent each leƩer with a specific number. To convert the stored binary numbers back into leƩers, you need addiƟonal contextual informaƟon, such as the code that was used for conversion. Examples of such codes include ASCII or Unicode.