Admission of Network System Design and Implementation

Paper Keywords: automatic database network database VFP Forms Pick explicit security lock
Abstract: This paper introduces the <<Network Admission System>> Forms Pick in the automated design and implementation; and the use of VFF defects database as a network database and improvements.

The strokes, brilliant idea Admission work has been widely used computer LAN or remote network and the achievement of the candidate information and the full acceptance of electronic information, computer management, significantly improve the efficiency of the admission process. But more is at this stage before Forms Pick Forms Pick mode to manual operation of the computer by hand, without the use of computer fast, powerful data sorting processing by the computer will auto complete the work Forms Pick .2000 developed himself as caught in Heilongjiang Xingzhaoshengban << Network Admission System> "and" <examination management system>>, the first time the network Enrollment Forms Pick automatic, so that students taking a more fair, just, and greatly improved work efficiency.

The system was developed, taking into account applicable to peer network, data reporting and downstream (at the time of the country are using VFP Shizhaoshengban or FOXPRO), system development and other factors of the gradient using VFP database. VFP database is the desktop as the relational database, as a network database using the existence of confidentiality, poor security, network data traffic flow and other shortcomings of the system to overcome these problems with a lot of effective methods, making application of this system to obtain a clear success, the system has been applied so far.

1, to improve database security, confidentiality means
VFP database table is clearly the way of file storage, file sharing over the network through the use of, and therefore its data security, poor security. In the system with the following two methods to improve data security, privacy .

(1) in the application system for network links, rather than start a network in WINDOws login link, application link disconnected from the network exit, which can hide the network links. Network Link WINDOws by calling the API function implementation, first with the VFP The external function declarations DECLARE command, call WNetAddC: onnection) add links to achieve, with Wnet-CancelConnection () broken links, etc., the specific use can be found in Microsoft's MSDN help documentation.

(2) to the total application run in the foreground. Implementations package set _screen. Windowstate = 2 to maximize the application window to automatically fill the screen); a screen. AlwaysOn-Top =. T. (always at the application system running in the foreground); _screen. minbutton =. f. (the user can not minimize the application window) and so on. This usage has nothing to do with the network itself, but used in conjunction with the foregoing paragraph, making the users in the system is running, not running in the foreground other tasks, you can not view the web links in the foreground, effectively concealed the network link, can well protect the data files on the server is not illegal to use, simple and efficient than other methods. and then for each user is assigned with a different user name, password, operating authority (which can be dynamically set with immediate effect), the operation log (critical operations throughout the operating track record), etc., to achieve effective protection of data, the application works well.

2 and improve data consistency and reduce data redundancy and reduce the amount of network data transmission, etc.

(1) The natural condition of the system of the candidates, their qualifications and preferences, taking all information into the results of a candidate data table, a record corresponding to each candidate, all to make use of the code fields. Additional history table stored Candidates Forms Pick, taking the track and so on. all kinds of school information form, a detailed classification of saving the school enrollment plan and other relevant information. There are a variety of codes table, the user management table, the operation log table and so on. the candidate information to a centralized storage table to maximize data consistency in candidates add a data table identification field, unity of various states that the candidate (Forms Pick status, admission status, after the reverse gears Forms Pick, admitted after the reverse gears direct admission, suspended state, the state death files, etc.). This admission of candidates to deal with many situations can only deal with this field, data processing is greatly reduced.

(2) VFP data operations are carried out on the local machine, generally can not be submitted by way of the process on the server side, and then returns the results. If every operation is fetching data from the server in the machine, the network too much data traffic, the network will be overwhelmed. For the Forms Pick user rights, admission, Tuidang, file hang, Append, modify, or delete data, the change to take a two-step operation mode, the first step in the user machine to the temporary table, second by <<submit>> button to write the server data table. two steps make use of only the submission of a database on the server, while significantly reducing network data traffic On the other hand facilitate the procedures to control, can keep the current editing operation such as waiting for a new submission. In the time of submission, under the circumstances used in the system file locking function flock () and record locking function rlock () on the server explicit table lock, the data written to address the problem of conflict. here an explicit lock mode, do not use VFP implicit locking mechanism to ensure the submission of a data editing the original language of the operation (either complete , or all do), to improve data consistency.

The system records the 100,000 candidates about the size of the main data table 40MB, while dozens of users, 10M LAN use, there was no network congestion phenomenon.

3, automatic Forms Pick
Automatic Forms Pick (or acceptance) means the candidates and the institutions of voluntary enrollment plan (can be specific to the professional recruitment program), according to the principle of specific Forms Pick (Score, etc.) line up to put in a certain proportion of candidates file or direct admission. to ensure fair Forms Pick by the candidates is the premise of volunteerism; Forms Pick of the complex realization of the principle is one of the difficulties; quickly and efficiently achieve and maintain complete Forms Pick trajectory to be investigated is the practical application of this system specific requirements. In addition, the need to support Forms Pick batches, sub Forms Pick, principle Forms Pick adjustable Forms Pick a separate individual institutions can be restored and so on. Through careful investigation and analysis of the candidates and to ensure institutions under the premise of fair admissions to design a more adaptive automatic Forms Pick method (principle) as follows:
(1) the same batch (Note: Forms Pick general categories according to enrollment, educational institution, such as fractional interval into multiple categories, in turn, respectively, corresponding to the number of lots) volunteer by volunteer sequential processing, in batch Forms Pick Score line candidates of the same order of preference based on the number of such institutions in order to determine the total Forms Pick processed only after entering a voluntary treatment. before a volunteer is not all discrimination is done, volunteers can not be the first follow-up treatment to ensure the fairness of the candidates and institutions.

(2) can be set within the same batch conditions by subparagraph Forms Pick Score loop. With some of the same volunteers have been disposed of within the next turn with a voluntary treatment, as specified in the same period were disposed of all the volunteer sub- low-income section of the treatment, recycling the process, until the batch Forms Pick the bottom line. The purpose of the introduction of segmented approach is: segment by setting different values, priorities will be voluntary and the priority score combination. min Section interval maximum value, that is no longer within the sub-batch is mainly voluntary order priority within the same order of voluntary only to score first; such as sub-interval take the minimum 1, mainly Score priority, with the sub- order of priority when the volunteers; taken by other sub-priority value, with a priority in order first to volunteer, volunteer in order then to score the same priority.

(3) for the same period, the same sequence of volunteers, volunteer for the same college (or professional) and candidates Forms Pick the same conditions, all Forms Pick for equal treatment (which may be beyond the Forms Pick a number of institutions).

(4) Forms Pick appropriate ratio of less than 1 to avoid the phenomenon of reverse gears. Reposted elsewhere in the Research Papers Download http://www.hi138.com (5) a lot could be divided into multiple small batches of independent the Forms Pick (different from sub-cycle within a batch processing). through successive lower division multiple batches Forms Pick Forms Pick the bottom line, higher than the batch of candidates failed to be supplemented by artificial Forms Pick Forms Pick the next, etc. Prior to processing a small batch, try to avoid those high scores get the job.

Figure 1 is achieved by the principle of the algorithm Forms Pick rough diagram.


In order to improve the speed of automatic Forms Pick, use the SELECT SQL statement fast in the main data table, select the candidates to meet the conditions to the temporary table records; used by the institutions need to manage table record Forms Pick the outer loop control, a processed in a voluntary institution, then the next institution in the voluntary treatment (because it is the same order of voluntary treatment, there is no intersection, does not affect the fairness), reducing the number of the record pointer orientation, effectively shortening the processing time ; in the loop filter into the candidates records, and to volunteer for the candidate records by institutions according to a condition that the logic of continuous Forms Pick (using index or sorting means. For some college or professional sort criteria separately Forms Pick set in line with the principles of the foregoing Forms Pick in its program management table is set, in order to reference), using the method pointer turn down a record deal with record, greatly accelerate the pointer speed. concrete implementation, can have under the characteristics of the database used to optimize. Experiments show that nearly hundreds of thousands of candidates across the province, about 200 automatic Forms Pick Forms Pick a college, in the Pentium-class PC (2000) two minutes to complete. to the institutions to vote file set entry settings, automatic Forms Pick can be used to some institutions (or part of the professional) in Forms Pick, you can also volunteer for only part of the Forms Pick and so on.

Forms Pick of the special needs of individual institutions, the system provides automatic Forms Pick a single function of the institutions, which can use a different sort order of voluntary drop points Forms Pick method (automatic Forms Pick can not use this method. Because the first treatment should not be more follow-up procedures voluntary, otherwise it will result in violation of the order and the institutions volunteer candidates inequality). The system also provides the conditions by entering the combination to specify the range of bulk Forms Pick Candidates function, used to supplement the Forms Pick a single institution.

Enrollment in the various Forms Pick automatic way of using a computer will greatly enhance the efficiency of admission, so students taking a more fair, reasonable and significantly reduce the social costs, while effective in increasing the number of volunteers, volunteers reported to the difficulty of reducing such candidates. Transfected affixed to the Research Papers Download http://www.hi138.com