An overview,
Directed against the exam cheating behavior in recent years, more and more to conceal, the phenomenon of cheating means more and more technical, to effectively combat fraud, put an end to this ugly habit, according to the relevant documents of the state education commission, the region will be in the unified national education examination within their respective jurisdictions fixed-point test television monitoring system is established. Such as guangdong province test center notice sent to the admissions office of guangdong cities and manages, unified national education examination in guangdong province designated venue will set up TV monitoring system in the next three years. Examination television monitoring system is mainly composed of front-end examination in camera equipment, transmission equipment, and the monitoring center control display video equipment composed of three parts. Examination TV monitoring system for examination examination process a comprehensive monitoring and real-time video, once the monitoring center of invigilation on duty when the teacher found that some candidates have abnormal phenomenon, in a timely manner through the console to control the test camera, enlarge location image forensics, relevant information will become the evidence in the future, the information kept by special video storage devices, to ensure the fairness of the exam.
Traditional way of examination room television monitoring system USES analog monitoring, need in each front cameras and video cable, audio signal lines between the monitoring center and control signal lines, and normally the testing and monitoring center distance is far, so need to spend a lot of manpower material resources through walls make hole buried pipe line. At a school twenty fixed-point test, each test two sets of cameras, each venue on average 200 meters from the monitoring center as an example, a total of 24000 meters of all kinds of wire laying. And if some of the examination room and the distance between the monitoring center is too long, in order to avoid influence transmission control effect, still need to add some specific relay equipment. In addition, in the monitoring center, to achieve control, display, video recording, shall be equipped with a monitor, long time delay VCR, image segmentation, control switch matrix, and many other complex equipment, and after some training of operators also need to master the operation of electrical equipment.
Therefore, no matter from the construction costs, construction difficulty, or the system application convenience into consideration, has become more and more is not adapted to the traditional way of simulation monitoring actual application needs of the examination room centralized monitoring system.
Second, the centralized monitoring and remote teaching demonstration system
Examination room centralized monitoring and remote teaching demonstration system are the latest international of the third generation of digital video monitoring system based on network products, completely overcome the shortcomings of the traditional analog monitoring system, and on the function and performance better. This system mainly using the latest computer processing technology, the front end of the examination room audio signal coding compressed into digital signal transmission through the network to the monitoring center, and then in the monitoring center will digital signal reduction into audio signal and display. Because at present in the campus, along with the advancement of national "JiaoJiao tong" project, more and more schools have high bandwidth network environment, and gradually access to the Internet, therefore the examination room centralized monitoring and remote teaching demonstration system can be achieved only through the network examination room centralized monitoring function. The examination room the core equipment of centralized monitoring and remote teaching demonstration system including network video server and network video monitoring system management software. Installed in front the examination room, the former mainly perform camera to capture video image coding compression into IP packets and upload network function; Which is installed in the monitoring center monitor computer, mainly performed to restore data into video signals, and a series of control, video, management functions.
The network video server, digital compression and network transmission technology as the core, adopts the most advanced digital video technology (mpeg-4), in accordance with industry standards and to meet the needs of Chinese customers IP network video monitoring products. The products can fully meet customer demand for remote video surveillance aspect, in the technical performance of the current video monitoring in the field of digital and networked two trends, has the distinct characteristics of high reliability, high integration, can be widely used in such as unmanned stationed for power substation, telecom equipment room, road traffic, schools, Banks, customs, chain business premises of the remote video monitor and supervise the local LAN network mode.
The examination room centralized monitoring and remote teaching demonstration system can realize the following functions:
Low monitoring functions
Directly by the campus network, can be seen in the examination room monitoring center computer in each classroom, can also be the situation of the classroom to switch to the TV to watch on the wall.
Low image segmentation round tour functions
Do not need to image segmentation, matrix switch control equipment, through cheung depending on the network video monitoring system management software, can realize the video images with screen display segmentation (1, 4, 9, 16 road), round tour shows more groups of picture.
Low examination room monitoring
Through the network video monitoring system management software, the scene of each test separately to switch to the TV monitor on the wall, or forward the control instruction, adjust the camera focal length or yuntai details of local observation.
When a video
Any test scenarios can be real-time or timing video, video or manual start-stop, alarm trigger video, video storage media as the computer's hard drive, video disk capacity of the space can be set up, and have automatic override function.
Low intelligent retrieval playback
Can press time, the test number, camera, alarm event condition such as intelligent fast retrieval playback recorded video data, playback frame by frame, slow play, constant speed, fast and enlarge/reduce a variety of ways, and can be arbitrary a playback stored image into a JPEG or BMP format images, used for data exchange or printout.
Low character superposition
Video on every road, can real-time overlay scene happened time and source, make the scene more complete information.
Low scene captured
In regional monitoring center master each control point in a computer or network computer to check the process, can at any time of window image of abrupt scene images captured preservation.
Low rights management
The operating rights classification management, according to the nature of work for each user gives different permission levels, system login, authority inspection operation, ensure the safety of the system.
When the principal control
The principal control computer through office can choose to see any screen in the examination room discipline.
Cruise on low remote network
The superior invigilation centre staff through the Internet (or wan) can monitor remote real-time sampling of the examination room. Also, do not need to add any cost, this system can be used to provide remote teaching demonstration function. We know that the advanced teaching experience, in order to promote good teachers or teachers' teaching level, the school often need to arrange for teaching demonstration class, but the traditional teaching model is put class people in the classroom teaching, not only limits the number of classes, also affect the normal teaching, and the traditional teaching model can only locally, for the inconvenience, from view of teachers. This system besides the teaching demonstration class can be broadcast live, real-time video, can also listen to the teaching demonstration class people do not need to enter the teaching scene can see live teaching demonstration, long-distance watching teachers can easily (or wan) via the Internet to watch the whole teaching demonstration class.
System design basis and the guiding ideology
Design basis
Mainly according to the actual needs of education industry, as well as the product in the process of the education system many times application experience, the bidding documents of proposed in the technical part of the overall construction of the target, system function, technical performance indicators, etc., when the design focuses on reference specifications for design of industrial TV system engineering, the MPEG4 audio codec standard - audio and video object coding part (6), 100 base - TX fast Ethernet interface standard, television monitoring project procedures and requirements, etc.
Design guidelines
This solution to satisfy the practical application as a starting point, make the most of the existing campus network in terms of video transmission in order to reduce the cost of the system to the greatest extent.
Low performance, advanced function: the equipment to ensure the leading technology, reliable performance, easy operation, practical, simple maintenance, the optimal price performance ratio, and extend the leeway. Equipment adopts adopted the advanced technology and production process manufacturing, after the completion of the system, three to five years will not lag behind.
Functional: low system can realize various kinds of practical application of the required functionality.
When the operation is simple and practical, using high-tech means, the intelligent design, try to reduce the complexity of system operation. And to work in the system is stable and reliable, simple maintenance.
Low appearance is beautiful: the front-end device installation are considering safety, concealment and beautiful sex.
Low system stability, reliability, the hardware were selected choose advanced, mature, reliable products, and have good operating performance.
Advanced: low system is the most advanced combination of software and hardware, and make it easier for system compatibility, upgrade, expansion, and adopt module design is simple to maintain.
The real time and low operational ease: all adopt standard WINDOWS window operation, and make the signal in real time to upload, truly real-time performance.
Low low maintenance: through modular, hierarchical design can be the basic elements of a system of free maintenance.
Low expandable: can conveniently according to the need for network step by step tandem, increase or decrease in all kinds of front-end equipment, etc.
Advantages and characteristics of the system application
Examination room centralized monitoring and remote teaching demonstration system powerful, not only in performance than the conventional video surveillance system. This system advantage mainly displays in the following aspects:
Functional integration, make full use of campus network resources
Conventional solution is to use multiple systems to realize the function, high cost and future expansion and upgrade is not convenient. This scheme used the advanced nature of modern computer network technology, multiple functional integration, not only make full use of advantages of campus network high speed accurately, but also easy to integrate the various service requirements in Intranet, reflects the advanced nature and economy.
Highly intelligent, automation teaching environment
Make full use of existing hardware and software equipment, greatly improved the teaching conditions, at the same time save a lot of time, the teacher and student to achieve digital teaching work.
High degree of openness
The adoption of an open network technology, campus network and the applications of this system services are based on the existing network hardware and software platform, system expansion only on the front end to increase the network video server hardware device or increase in the monitoring center computer equipment without any complicated process, really high degree of openness.
economy
Using the campus network, need not laborious laid complex transmission lines, the cost of the system under the condition of the same equipment configuration and function requirements, save about 30% than conventional system models.
Maintenance simplified
Conventional solutions are usually use multiple systems, set to solve all kinds of complicated equipment, its maintenance is also need different professionals. This system based on campus network, the use of computer system processing technology, due to the powerful network function, but also implement the remote operation and maintenance, maintenance of the system simplification, but also reduce the follow-up maintenance.
Excellent image quality
USES the advanced mpeg-4 codec technology, image clear and natural. Standard resolution 352 x 288 pixels, up to 704 x 576 pixels, and can be customized. Image flicker-free, good continuity, standard image frame rate of 25 frames per second (PAL), 30 frames per second (NTSC format). Especially suitable for the application of the examination room for detail observation.
Low bandwidth
Adopt unique adaptive P frame and B frame compression technology, further enhance the compression ratio of the mpeg-4 compression algorithm, with IP multicast function, greatly reduces the browsing the images of network bandwidth. The images at 25 frames per second, 352 x 288 pixel resolution, bandwidth is only an average of 250 KBPS, users under the condition of the same network can transmit video because several times, virtually to save the user's network resources.
Low latency
Mpeg-4 strengthen the standard encoding technology, the remote video transmission delay less than one second, greatly improved the remote real-time monitoring results. 9, unlimited remote real-time surveillance video site
USES the unique flow technology, break through the limitation of traditional way of digital surveillance (note: the traditional way of digital surveillance USES the hard disk video recorder or industrial computer and video compression CARDS as standing video processing unit, although better than analog monitoring, but cannot be multiplex compressed video signal and uploaded to the monitoring center.) , but at the same time for unlimited multiple monitoring site implement remote real-time surveillance video images.
The system structure and flexible
With a standard network mode, support IP unicast and multicast function, can form a point-to-point monitoring system, and can form a center for the system of each site. Can set up multiple points in the network control image workstation, meet the needs of multiple users, you can also use the WEB form multi-level monitoring system.
Expandable strong sex
Adopting modular design, can achieve smooth side expansion, expansion and center and control capacity. Both expansion and single-stage or multi-stage expansion can make full use of the previous resources, expansion and lower cost.
Operational ease
Video monitoring center network centralized monitoring system management software platform is Windows NT / 2000 Chinese, control the graphical interface, interface, menu for all Chinese, user can very quickly familiar with the use of the operating software.
Independent development
The core of the system hardware equipment and management software are independent development, can provide good after-sales service, timely response to the user's special demand, based on the user's requirements tailored to function.
System network structure
The examination room centralized monitoring and remote teaching demonstration system for into the remote viewing monitoring scope of the there is no limit to the number of the examination room, mainly depending on the application environment of network conditions. So basically system according to the need to monitor the examination room number free combination definition, system can way multistage network at the same time, the formation of large-scale remote centralized monitoring network.
According to the application characteristics of the education industry and the management pattern, the examination room tour monitoring system is basically divided into remote network examination center, the local examination monitoring center and front-end examination system of three-level network structure. System in the examination room equipped with one or more network video server (number of concrete depends on the size of the population of the testing surveillance cameras), completed in the eye of digital compression and coding audio signal processing, packaged into IP packets on the IP network transmission; Local venue monitoring center monitoring host using the testing with the passage of the network between the monitoring center, receives the testing front-end network video server upload audio information, at the same time by "network video monitoring system management software" for remote real-time monitoring.
In all parts of system composition and configuration requirements
As mentioned earlier, according to the application characteristics of the examination room monitoring and management mode, xiang depending on examination room centralized monitoring and remote teaching demonstration system basically divided into remote network tour test center, the local examination monitoring center and front-end examination system.
Tour, remote network examination center and local monitor center functions, mainly including host, display devices, video monitoring management information storage devices and network video monitoring system application software. Front end test system consists of cameras and accessories, audio equipment, network video server, alarm equipment (optional), etc.
Video, audio, alarm information, the network video server after compression, uploaded to the monitoring center through the network, complete the real-time monitoring, to master the examination room scene. The monitoring center can implement the management of examination room monitoring equipment, alarm information query, image browse and control, and other functions.
Considering the characteristic of the examination room monitoring system construction, the examination room centralized monitoring and remote teaching demonstration system with good scalability. Each function part adopts modular structure, very easy expansion, convenient, flexible configuration, network and has a good user interface. Low in the system to add new test point, the test will only access networks and network video server in the center to do simple configuration;
Low is not affected by the expansion of the system functions and operation;
Low system has the capability of multistage network to form the examination room monitoring network of the whole province and even the whole country.
Front end test monitoring section
Test monitoring front part of the equipment installed in the testing site, complete the examination room scene all kinds of video, audio, alarm information collection, processing, upload, mainly can be divided into network video server, the monitoring and controlling of the peripheral equipment of two parts. Configuration of each part and the request is as follows:
The network video server is the test of centralized monitoring and remote teaching demonstration system at the core of the equipment, the main features include:
Low to collect the testing field of video images and background sound, after compression to the local tour to take an examination of the monitoring center and remote network center;
When necessary, through the network connection decoder, according to the monitoring center of operation command control video switch, control the lens focus, close shot/vision, aperture adjustment, yuntai, up and down or so control and automatic touring action;
According to the alarm message of alarm equipment, realize JingShi linkage video recording, warning lights, alarm control equipment such as automatic start, automatic with subtitles, hints of sound and light alarm. Achieve a certain area of anti-theft alarm function.
Need special pointed out that as a result of the unique performance and powerful function of the network video server, network bandwidth between the testing and monitoring center permission, it can take all the testing front-end monitoring object of real-time video images uploaded to the local tour test center and the monitoring center and remote network shows at the same time. And adopting digital hard disk video recorder test digital monitoring system due to its structure, cannot achieve this function.
Due to different schools, the examination room of actual monitoring environment, peripheral monitoring equipment types, structure and organization structure, especially the camera point layout and the type of camera has a certain number of differences, on the whole in order to meet the basic goals and requirements for the principle of image monitoring configuration. Peripheral monitoring equipment mainly includes color video camera, black and white video camera, etc., and form a complete set of yuntai, shields, bracket and cloud mirror decoder, etc., and according to the need to configure the alarm detector, microphone, speaker and other audio equipment. General requirements indicators are as follows:
Color video camera, the light sensitivity values < 2 lux, articulation > 470 line.
Black and white video camera, light sensitivity values < 0.5 Lux, articulation > 400 line, backlight compensation function.
Yuntai, shields, stents, indoor type yuntai, shields, support requirements have rust corrosion function.
Low cloud mirror decoder with RS485/232 interface, through the network and the network video server transparent channel is connected, directly controlled by the network video server, according to the scheduled programs or the operation of the monitoring center staff instructions, execute the haeundae and lens control object control.
The monitoring center
The monitoring center tour including the concept of remote network test center and local monitor center. Remote network tour test center, in the form of rights management management monitoring the local school examination room monitoring center, tour the function of the test center and local monitor center function is basically the same, so in the narrative in local monitoring center, for example.
The basic function of the monitoring center is completed, the local examination room monitoring image real-time display, control, storage, management, and other functions, the hardware system is mainly composed of monitoring host, display devices, network interface and other components of the equipment, storage, printing equipment, its core is "network video monitoring system management software.
Monitoring center monitoring host install Windows operating system and network video management software, centralized monitoring system is equipped with large capacity hard disk according to need or external storage devices, the host hardware requirements for more than 2 g P4 CPU, more than 256 MB of memory, with 32 MB video memory computer graphics. Monitoring host as the center of the monitoring system operation platform, is mainly responsible for receiving, storage, analysis, statistics and query the remote test upload audio, alarm, data signal, at the same time perform powerful system management functions, including user and set user permission management system, management and equipment configuration system, linkage alarm information processing, as a network server management network users and network equipment, etc. And all this functions are based on network video monitoring system on the implementation of management software as the core.
Leadership (the principal) control center
Points control center can according to need in each leadership designated offices, points control center system using common desktop computer hardware requirements, through the IE browser (such as the need to also can be installed network video monitoring system management software) within the scope of the authority of the testing real-time monitoring.
Performance of the system and the main parameters
Video formats: NTSC or PAL format
Video compression method: mpeg-4 image compression coding
Video resolution: standard 352 x 288 pixels, customizable, maximum 704 x 576 pixels
The frame rate of 25 frames per second (PAL), 30 frames per second (NTSC format), downward is adjustable
Audio compression standard: ISO - the MPEG Audio Layer 3
System availability > 99%
At the same time, can monitor the examination room number > 30
Streaming video bandwidth: an average of 250 KBPS (352 x 288 resolution, 25 frames)
System average trouble-free working hours: MTBF > 30000 hours
Hardware average trouble-free working hours: MTBF > 100000 hours
Average system maintenance time: the MTTR < 0.5 hours
Surveillance footage showed time difference between actual incidence and < 0.5 seconds
Event alarm to the system automatically records the corresponding screen time < 0.8 seconds
The alarm sensor alarm to the background information display time < 0.5 seconds
