Chapter 13-11-AM

Source: Internet
Author: User
Tags disk usage

1. During program executionThe hardware is automatically completed.

The cache and master memory address images require dedicated hardware to automatically complete. using hardware to process the images has a higher conversion rate.

2. The number of digits of the instruction register depends on the instruction length.

The instruction register IR is used to store the commands to be executed, so it is related to the instruction length.

3. if the computer stores data using a pair of symbol bits {00 represents the positive number, and 11 represents the negative number}, when the two symbols have the same number, if the two symbol bits of the calculation result are logically exclusive or calculated 1, it can be concluded that the result of the two numbers is overflow.

The computing overflow detection mechanism of the computer uses dual-symbol bits. 00 indicates the positive number, and 11 indicates the negative number. If it is carried, the symbols are inconsistent and overflow is detected. When the result is 01, it is called overflow; when it is 10, it is called underflow. As a result, if two sign bits are exclusive or when overflow occurs, the result is 1.

4. If the computer is 32 characters long and the memory capacity is 2 GB, the address range is 512 MB.

The computer is 32 characters long and can be edited by words (that is, 1 word 32 characters, 4 bytes). Then, the address occupied by 2 GB memory is 512 MB.

5. Among the following network attacks, DoS attacks are SYN flooding attacks.

DOS is short for Denial of Service. DoS attacks are called DoS attacks. The purpose of DoS attacks is to make computers or networks unable to provide normal services. The most common DoS attacks include computer network bandwidth attacks and connectivity attacks.

6. In the PKI System, the private key of the CA is used to sign the digital certificate.

7. public key encryption algorithm: ECC, DSA, RSA symmetric password system: des

8. Vector graphs are commonly used image representations. elements are the basic component units used to describe vector graphs.

9. xara3d: animation editing and processing Cool Edit Pro: digital music editor and MP3 production software

10. There are three ways to describe basic processing: structured language, judgment table (decision table), and decision tree ). The basic principles of basic processing logic description are:

A) each basic data flow graph must have a basic processing logic description.

B) The basic processing logic description must describe how the basic processing converts the input data stream into the processing rules of the output data stream.

C) The processing logic description must describe the processing strategy rather than the details.

D) The information contained in the processing logic description should be adequate, complete, useful, and non-redundant.

11. when dividing a module, the function scope of a module should be within its control scope. If it is found that its function scope is not within its control scope, the parent module will be moved down, it is inappropriate to make the decision at a higher level.

The function scope of a module refers to the set of all modules affected by a decision in the module.

A module is a set of modules and all its subordinate modules (directly or indirectly affiliated with its modules.

The scope of a module should be within its control, and the module to be determined should be as close as possible at the level of the affected module. If the module is found to be out of its control scope during the design process, you can use "move up judgment point" or "Move down the module affected by judgment, move it down to the control scope of the module to improve it.

12. known grammar G: S-> A0 | B1, A-> S1 | 1, B-> S0 | 0, where S is the start symbol, starting from S, you can export strings with equal numbers of 0 and 1.

S-> A0; A-> 1----------10;

S-> A0; A-> S1; s-> A0; A-> 1-----------1010

13. A file management system uses a map to record disk usage. If the system is 32 characters long, the size of the physical block on the disk is 4 MB, and the number of the physical block is 0, 1, 2 .... the number of map characters in sequence is 0, 1, 2 .... the usage of the physical block No. 16385 is described in the 513rd words of the In-Place graph. If the disk capacity is 1000 GB, the graph needs 8000 words.

(16385 + 1)/32 = 512.06 ----- 513; one word corresponds to 32 physical blocks, the size of the bitmap is 1000*1024/(32*4) = 8000

14. In the software project activity diagram (PERT), the longest time-consuming path from the Start Node to the end node is the Key Path.

15. Reverse Engineering product design can be considered as a process from product to design. Simply put, reverse engineering product design refers to the process of reverse product design data (including various design data models) based on existing products. When this process is used for development, the reverse engineering is usually used to analyze the design from the code first, and then analyze the requirements from the design. At this time, the new requirements are added, and then the forward engineering route is taken, form a new system. Reverse engineering is carried out in the demand analysis phase.

16. Sei Capability Maturity Model divides software development enterprises into five maturity levels, of which level 4: management level focuses on product and process quality.

17. The module structure review mainly includes the following aspects:

A) Control Flow Structure: Specifies the process relationship between the processing module and the processing module. Check the control transfer relationship and Control Transfer Form (call method) between processing modules ).

B) Data Stream structure: describes how the data module is processed by the processing module. Check the correspondence between the processing module and the data module. The access relationship between the processing module and the data module, such as creation, deletion, query, and modification.

C) correspondence between the module structure and the function structure: including the correspondence between the function structure and the control flow structure; the correspondence between the function structure and the data flow structure; definition of each module (including functions, input and output data ).

18. The year and month entered by a program calculate the number of days of the month. The input parameters include year (positive integer) and month (1-12 ). If the test method is divided by equivalence classes, (c) is not a suitable test case (the output of the test is displayed after a semicolon ).

A. (maid; 31) B (2001; "error") C (; "error") D (,-1; "error ")

General principles for writing test cases:

1. Design a new test case so that it can cover as many valid and other values as possible, and repeat this step until all valid and other values are covered.

2. Design a new test case so that it only overwrites an unoverwritten invalid equivalence class. Repeat this step until all invalid equivalence classes are overwritten.

C overwrites two invalid equivalence classes at the same time, so it does not match

19. Module interfaces, local data structures, and important execution paths are the main inspection content of unit testing.

20. Domain-class models do not contain domain objects.

In the domain class model, attributes and operations that describe the situation are involved, and associations between classes are also described, but there is no content at the object level.

21. Database relational algebra: Sum, intersection, difference, Cartesian Product (x), projection (PI), selection (σ), join (join, ∞)

If R (A, B, C, D, E) and S (B, c, f, g) are related ), then there are seven attribute columns after the R and S natural join operations, which are equivalent to the expressions Pi1, 3, 4, 7 (σ 3 <6 (r ∞ s: select a, c, d, f from r, s where R. B = S. B And r.c = S. C and r.c <S. f

22. Distribution transparency means that users do not have to care about the logical partitions of data, the physical location allocation details of data storage, or the data models of databases on the local field. Distribution transparency includes partition transparency, location transparency, and local data model transparency.

23. In a directed graph G's topological sequence, vertex VI is arranged before VJ, indicating that there may be paths from VI to vj in Figure G, but not from VJ to VI.

Topological sequence is the output of topological sorting. To sort the topology of a directed acyclic graph G, all vertices in G are arranged in a linear sequence so that any pair of vertices u and v in the graph, if the edge (u, v) E (G), then u appears before V in linear sequence. It can be seen that if vertices vi are arranged before VJ, it indicates that there may be paths from VI to vj in Figure G, but not from VJ to VI.

24. Construct a binary tree. If the length of the weighted path reaches the minimum, such a binary tree is called the optimal binary tree. A tree with the shortest length of a weight path, a node with a large weight value is very close to the root, and a tree with a small weight value is far away from the root.

25. When hash is used for data storage, the P value in the hash function is very important. Because this value directly affects the conflict rate, the value of P is generally a prime number close to the number of elements N but smaller than N.

26. during the transition from IPv4 to IPv6, if you want to use two IPv6 nodes to communicate through the existing IPv4 network, you should use tunneling technology; to allow a pure IPv6 node to communicate with a pure IPv4 node, you need to use translation technology.

Dual-Protocol Stack: the host runs both IPv4 and IPv6 protocols, and supports both Protocols.

Tunneling Technology: this mechanism is used to connect IPv6 sites on IPv4 networks. A site can be either a host or multiple hosts.

NAT-PT: the translation gateway is used to convert the IP header address between IPv4 and IPv6 networks, and the semantic translation of the response to the packets is also made according to different protocols, this allows transparent communication between pure IPv4 and pure IPv6 sites.

27. POP3 protocol uses Client/Server mode for communication. When the client needs services, the client software establishes a TCP connection with the POP3 server.

Barely: Almost none

Alternate: standby

Delivery: Delivery

Construction: Construction

Algorithms: Algorithm

Concept: Concept

Management: Management

Advance: Advance

Cost: Cost


Chapter 13-11-AM

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