Essentials of Review of Software Development Technology Foundation

Essentials of Review of Software Development Technology Foundation

1. Life cycle:

Refers to a software from the beginning of the development requirements, after the demand analysis, design, manufacture, commissioning, use, maintenance, until the software products are eliminated the entire process.

2. Briefly describe the fundamentals of software engineering:

1. Strictly manage with a phased life cycle plan;
2. Adhere to the stage review;
3. Implementation of strict product control;
4. Adopt modern programming technology;
5. The results should be clearly examined;
6. The development team should be small and refined;
7. Recognize the need for continuous improvement in software engineering practices.

3. Describe the causes and solutions to the software crisis:

Reason: There is a sharp contradiction between the high cost of developing software and the low quality of software products, which causes the software development to fall into circulation, that is, the development of software system requires a great deal of manpower, financial and material resources, but the quality of the system cannot be guaranteed.

Methods: A. Fully absorbing and drawing on the effective principles, concepts and methods that human beings have been engaged in for a long time in engineering projects;

B. Promote the successful technology and methods of developing software summarized in practice, and study more effective techniques and methods;

C. Develop and use better software tools based on different application domains.

4. Brief introduction of B/S mode: (browser/server, browser/server System)

A.B/S system is a kind of b/w/d three-layer structure system;

B. The first-tier client is the interface between the user and the entire system, and the client's application is a common browser;

C. The second layer is the Web server, initiates the corresponding process to respond to processing requests, and dynamically generates a string of HTML code embedded in the processing results, returned to the client's browser;

D. The third tier is the database server, which coordinates application requests made by different Web servers.

1. 1. queued operation: If the queue is not satisfied, Insert element x at the end of the team as the new team tail;
   2. Outbound action: If the queue is not empty, delete the team header element and use E to retrieve the value of the element;
   3. Span style= "font-size:10pt" > Take the team head element: If the queue is not empty, then use E to retrieve the value of the enemy element.
3. What are the traversal methods of the diagram? How is the concrete process implemented?

   methods: Depth-first traversal (Depth-first search) and breadth-first traversal ( Breadth-first search).

   procedure:

   a. depth-first traversal:

Basic idea: first a vertex V0 start, Access this vertex, and then click V0 the adjacent vertex start depth is first traversed until all the V0 the vertices that connect the paths are accessed, and if the vertices are not accessed at this point, a vertex is selected as the starting point, repeating the process until all the vertices are accessed. It can be seen that the depth-first traversal is a recursive process.

An no-show graph in

The resulting sequence of its depth-first traversal is: 0->1->3->7->4->2->5->6

B. Breadth- first traversal:

first, from a vertex of the graph V0 departure, visit the V0 then, in turn, access the V0 adjacent non-visited vertices, then starting from these vertices, breadth-first traversal, until all the vertices are accessed.

As in

The resulting sequence of its breadth-first traversal is: 0->1->2->3->4->5->6->7

1. The principle and process of Primm algorithm are briefly described:

   Basic idea: The PRIMM algorithm is a kind of algorithm to construct the minimum spanning tree, which constructs the minimum spanning tree by the way of connecting vertices to each other;

   process: from Connected networkN = {V, E}A vertex in au0Select the edge with the minimum weight associated with it(u0, v), adding its vertices to the collection of vertices in the spanning treeUthe. Each subsequent step from one vertex to theUWhile the other vertex is not inUSelect the least-weighted edge of each edge in the(U, v),Add this edge to the edge set of the spanning treeTE, add its vertices to the collectionUthe. This is done repeatedly until all vertices in the network are joined to the spanning tree vertex collectionU.

Explanation Link: http://www.cnblogs.com/wuchanming/p/4147419.html

1. briefly describe the five main functions of the operating system:

1 , CPU and Process management: Yes CPU reasonable allocation of time;
2, storage Management: The main memory allocation and management
3, equipment management: According to a certain equipment allocation principle of equipment allocation, so that equipment and host can work in parallel, to provide users with a good interface for equipment;

4 , File Management: Effective management of file storage space, reasonable organization and management of file systems, for file access and File Protection to provide effective methods and means;
5, man-machine interface: or user interface, refers to the interface provided to the user to operate the computer, generally by the command interface and program interface of two types.

2. Real-time operating system: RTOS

refers to when external events or data generated, can be accepted and processed quickly enough, the results of the processing can be within the specified time to control the production process or to respond quickly to the processing system, scheduling all available resources to complete real-time tasks, and control all real-time tasks coordinated operation of the operating system. Providing timely response and high reliability are its main features.

3. Brief description of segment storage Management technology:

The address space of the program is divided into segments, each segment is assigned a contiguous partition, each process has a two-dimensional address space (segment number and intra-paragraph address), the segments of the process can be dispersed in the memory of different partitions.

4. What is a process? What are the statuses? How do I convert?

A. a process is the execution of a program, is the operating system for resource scheduling and allocation of independent units;

B. There are three kinds of states: ready, running, waiting;

c. Conversion:

5. What are the main differences between processes and threads:

A. a process is an execution of a program that a thread can understand as a fragment of a program that executes in a process.

    b. The process is independent, which is manifested in the memory space, the context, and the thread runs within the process space.  
    c. generally (no special technology) the process is unable to break through the process boundaries to access storage space in other processes, and threads that are in process space share the same memory space as the threads that are generated by the same process.
    D. The two-segment code in the same process cannot be executed at the same time unless the thread is introduced.  
E. threads belong to the process, and the threads generated by the process will be forced to exit and clear when the process exits.  
    F. The thread consumes less resources than the process consumes.  
    G. processes and threads can have priority.  

1. Brief description of the differences and interlinkages between data, databases, database management systems:

A. Data (Data) : Is the basic object stored in the database;

symbolic records describing things are called data. The types of data include numbers, text, graphics, images, sounds, text, etc. Data and its semantics are non-divided.  

b. database db" : A database is a collection of organized, shareable data that is stored in a computer for a long period of time.

      c. database system (database sytem dbs) : Database system refers to the system structure after the introduction of database in computer system, generally by the database, database management system ( "  

1. Database management System (DataBase Management sytem, referred to as DBMS) : The database management system is a layer of data management software located between the user and the operating system, which is used to organize and store data scientifically and to obtain and maintain data efficiently. The main functions of DBMS include data definition, data organization, storage, management, data manipulation, database transaction management and operation management, database establishment and maintenance function.
2. Therefore, the data is a part of the database, and the database is the main object of the database management system.

2. external mode:

Also known as sub-mode or user mode, it is a description of the logical structure and characteristics of local data that the database user can see and use, a data view of the database user, and a logical representation of the data related to an application. Understanding: ① A database can have multiple external modes; ② The external mode is the user view; ③ External mode is a powerful measure to ensure data security.

3. Referential integrity rules:

It is required to constrain the relationship between two relationships by defining a reference rule between the outside keyword and the primary key.

Entity Integrity rules:

The keywords in a tuple in a relationship cannot be empty and are unique.

4. Multimedia Technology:

refers to the use of computer through the interactive mixing of graphics, video, text and audio, digitized way to integrate together, so that the computer has the performance, processing, storage of multimedia information synthesis and interaction capabilities.

5.TCP/IP protocol: transmission Control protocol/internet Protocol

     AKA network communication protocol, is internet most basic protocol, internet The foundation of the international Internet, by the network layer of the ip protocol and Transport layer tcp Agreement composition. tcp/ip defines how electronic devices are connected to The Internet, and the standard of how data is transmitted between them. The protocol uses the hierarchy of 4

1. TCP responsible for discovering the issue of the transmission, a problem on the signal, the need to retransmit, until all data safe and correctly transmitted to the destination.
2. IP is for each Internet-connected device provides an address.

Essentials of Review of Software Development Technology Foundation