Kaimeng Sun

Progress of China Agricultural Information Technology Research and Applications based on registered agricultural software packages

Keywords: Agricultural Information Technology, Applications, Agricultural Modernization

By using classified agricultural software products registered during last 15 years from 1994 to 2009, the author analyzed data and statistics in order to look at growth in number of the agro-software packages, their application areas, and research and development organizations, as well as their contribution to the agricultural IT industry in China. Based on the analysis, the article also assessed current agricultural IT sector development and provided some suggestions on further progress.

Introduction

It is well accepted that development software for agricultural application marks the progress in IT applications in rural development, as well as an important indicator of a country's modern agriculture.

Along with fast development of computer technologies in hardware and software, information technology products such as computers, TV, and cell phones have become popular in rural areas in China at a dramatic speed. China's central government, local administrations, and agricultural departments have invested much more in IT in the agricultural sectors. Over the recent past years, computers are more popular and network infrastructure has been development at unprecedented speed in China's rural areas. These provide conditions for IT applications in the agricultural sector, as well as require more on the R&D on agricultural software products. In other words, due to more computers and Internet are used in some rural counties, agricultural software run on the computers becomes an urgent need for IT developers.

China's agricultural IT (AIT) has been developed since 1980s. Early focuses were on agricultural data processing, databases, agricultural expert systems, and crop modeling systems, etc. These applications were generally based on collecting lab data, few directly applied in practical agricultural production and rural lifestyle change. Since the approaching in to IT era, information services for agricultural production, agro product processing, product mobilization, and agricultural supply chains become critical and need software products in providing the services. The increased number of software packages is partly due to more and more developers and research capacities. As a large agricultural sector, Chinese central government paid great attention to the sector investment so that research and development capacities have significantly improved and therefore promoted more agricultural software packages.

Improved awareness of software copyright protection

With more and more agricultural software products in the market, the awareness of intellectual copyright is improved among researchers and software developers. It is realized gradually that software registration would be one of the best approach to protect developers' efforts and their copyright in the software market. More registered software packages also mark the capacity of developing organizations and software scientists and become an important indicator of scientific research results. Acceptance of intellectual copyrights by the public also encouraged agricultural science research and software development in return.

AIT Applications

According to the statistics of the registered agricultural software packages, author identified 9 classes of the packages in terms of their application areas: information service for macro agricultural related decision making, agricultural economy management, village management, crop production management, animal husbandry production management, rural business management, agricultural ecological monitoring and control, agricultural information service, and agricultural software tools, mainly including software modules and developing tools. From the above figure 2, we can draw the following findings:

3.1

Crop production management software is most widely applied.

Among the registered agricultural software packages, 187 packages are agricultural crop production management software, or 21.2%, concerning wheat, corn, cotton, rice, beans, and vegetable crops. Functions of the software packages include numerical simulation of crop growing process, planting management, pest diagnose, crop management decision support, and expert systems. As grain and economic crops are main agricultural products in China, computerized information systems are mostly utilized to help solve problems during crop production and become focal point of agricultural research. Since crop production is critical in China's agricultural sector, production decision support software packages take the major market of software products, including decision support on breed selection, fertilizing, irrigation method, optimal yields, pest prevention, field management measures, etc. Crop models, expert systems, and DDS have been developed to practical applications to provide services for agricultural production services. This is very positive trend. Many software packages focus on both agricultural science laws and practical problem solving objectives.

More attention to agricultural information service functions

Information service software packages can include agro-product supply, information service, market information, network, and technical training information, etc. Among the survey, this type of software packages take 19.1%, totaled 166. Because vast Chinese territory are rural areas, many remote countryside communities has poor information access and with very traditional production ways. Through agricultural information service such as Internet and cell phone information dissemination, it helps local farmers to communicate with market and provide useful technical information and exchanges. Their crop product information will also be known through the network by demand side. These systems provide stored data, service functions, and rich market information. It can promote market oriented agricultural production, encourage product chain, and help increase farms income so that the agricultural sector will be more effective, convenient, and developed.

3.3

Environmental protection gained more focus in the AIT research.

This class of software packages has functions on data processing, analysis, and information service of water resources, soil, and climate data. Natural resources are basis for agricultural production and rural life because all aspect in agricultural production and rural life will depend on local natural conditions. Therefore, the agricultural environment software type focus on functions of climate disaster forecast, field condition monitoring, soil water content analysis, irrigation planning, land uses, etc. The increasing availability of this type of software packages indicate that agricultural conditions get more attention and research on the agricultural environment is going deeper. To make sure favorable agricultural environment will be necessary for prosperous agricultural production and for local farmer income.

3.4

Software applied for animal husbandry production maintains continuing progress.

Early in 1980s, computer programs were used for feed formula in China. Software applied for animal husbandry production therefore became one of the earliest applications. Along with the improved computer technologies, animal husbandry software packages develop accordingly. Applications also expanded from the early feed formula to animal husbandry production quality, poultry disease diagnoses, computerized production management, and so on. Especially because of recent fast development, the animal husbandry software packages are targeting large farms and household farmers. Since animal husbandry's high profit than crop farming, they buy these packages. According the survey, there are 82 registered software packages for animal husbandry applications, accounting for 9.5% of the total in the part 15 years.

3.5

New applications for rural economy and village management.

As China central government focus on agriculture and rural development, daily management in rural areas becomes one of the fast growth in AIT applications. Office automation in rural areas will include financial management, administrative affairs, and material management, especially in financial planning, debt management, clinic operation, farmer management, etc. Application of these software packages make the management in rural areas improved greatly. It helps efficient management. There are a total of 113 rural economy and management software packages surveyed.

In particular, rural management software developed very fast since 2005.

AIT Research and Development Capacities

4.1

Agricultural research institutes and universities are major developers of AIT packages.

According to the statistics over copyright holders of the 867 software packages, 337 or 38.9% are developed by agricultural academies, 89 packages are developed and owned by agricultural universities, accounting for 10.3%. Sum of the two types are about 50% of the surveyed agricultural software packages. This demonstrates that agricultural research institutes and universities are major developers and take the lead in software research and development.

Among the agricultural research organizations, national and provincial agricultural academies take the lead in terms of rich agricultural data sets, sufficient developer team, excellent computer infrastructures, and large number of various agricultural experts. Meanwhile, local and national financial support also makes them the mainstream of agricultural information technology research and development.

The important role of computer software companies

There are 241 software packages were developed by computer software companies, accounting 27.8% of the total. The author finds out that software companies play important role when end users are not professional in developing the software. Some software companies obtain their developing contract from bidding national and local government projects.

Over the recent years, professional agricultural software development companies grow fast, partly owned by agricultural research organizations and market oriented independent companies specialized in software development. Involvement of the software companies help introduce advanced technologies into the agricultural software market and help improved abundance of the products. At the same time, they also promoted progress of AIT software and benefit both company business and AIT advancement.

4.3

More institutes and universities take part in agricultural software development.

More and more non-agricultural research institutes, colleges, and universities are involved in the AIT R&D activities, organizations such as Chinese Academy of Sciences, Wuhan University, etc. Some of them develop the software packages through winning bid for national and local projects; some take part in the joint research program. The universities and research institute take their advantages of technical strength and make their contribution in the agricultural studies. This joint development helped focus on agricultural issues, and contributed to competition with agricultural sector capabilities. Of the surveyed software packages, 101 registered software systems were developed and owned by academies and universities, accounting for 11.6% of the total.

4.4

Most of the property rights owned by organizations.

Of the agricultural software package registrations, 808 packages are owned by organizations (93.2%). In China, these organizations are major developers, including research institutes, universities, software companies, or government departments. Even some privately registered packages may have been funded by some organization. This percentage tells us that most of the AIT products are funded publicly and their objectives are public service oriented. We can affirm that under the current rural economy, it is not practical for AIT project profitable enough. Social benefit is still a major objective.

Conclusions and Recommendations

From the above research and development status and analysis on the registered agricultural software packages, we can conclude the following in terms of progress and challenges:

AIT develops successfully in China.

The registered 867 agricultural software packages in the past 15 years demonstrate a fast development. Significant progress has been made in copyright protection, capacity building, and expanded application areas. Due to the increasingly high attention to agricultural sector in China, information technology roles in supporting agricultural production and technical service have become common understanding by researchers and developers. This has changed significantly compared with the situation in 1980s when only few devoting organizations and lack of technical capacities.

R&D on AIT products is developing towards effectiveness and efficiency.

In the past, software development focused more on technical advancement but practical applications. Many projects ended with submitted research results, with very weak application support. Now because computers are popular in agricultural sectors, insufficient software systems become a challenge. Current study projects attach great importance to demonstration and applications. Therefore, many software packages are developed for such demonstration and application purposes, such that features and functions of the software systems are more local condition oriented, and achieved satisfactory results.

R&D of agricultural software meets new demands of today's agriculture development.

Like other sectors, agricultural software must follow updated demand on functions. Along with improved agriculture management and farmer education, some critical problems must be addressed in AIT system development.

For instance, early focus on crop models and expert systems in dealing with planting and management must be further improved to solving problems of agricultural product quality. Some recently developed packages focus more on quality and safety. More and more software are using to trace quality in production chain. Again, environmental protection has drown more attentions such that increasingly more software packages are used in analyzing water and land resources, human resource optimization and monitoring.

5.4

Popularization of AIT systems must be strengthened.

There are anyway only hundreds of registered agricultural software packages. This is far insufficient in terms of China's large rural area and agricultural population. Even of the current software packages, very limited number of packages is suitable for agricultural production and rural population demands. Many such packages need to be improved for better agricultural applications. Therefore, central and local governments need to apply and popularize the existing products. If the heavily invested current systems were not fully applied, it will be a huge waste. Though some specially planned demonstration and application projects, it is not enough. Further investment shall include both capital and human resources to improve the effectiveness and efficiency of agricultural software applications. Otherwise AIT progress will be not as expected.

Promotion of agricultural software needs joint efforts by government bodies, research institutes and rural users by working together closely. Under the current situation, sales of the AIT software systems can hardly profitable. Therefore, capital support from government will be needed for software development, technical training, and hardware investment. Only by these supports, agricultural software can be applied effectively and efficiently.

Currently, improving applications of existing agricultural software packages is an important task for promoting AIT applications. Only by increasingly more applications, can the research and development of AIT systems progress at a sound basis. In return, the national and local investment will be paid off and AIT development progressed. This will facilitate AIT to provide greater contribution to agriculture production and to farmers' technical service. And finally it will contribute to modern agriculture in China.

  figure 1 gives a picture of growth in quantity of the 867 AIT systems registered at China Copyright Protection Center.

Fig 1 .

 1 Fig 1. AIT systems registered over years.

Fig 2 .

 2 Fig 2. is the distribution of the 867 agricultural software packages in application areas.

Fig 3 .

 3 Fig 3. in the following presents the distribution of the 867 registered agricultural software packages over copyright holders, universities, institutes, and private developers.

Number of developed AIT systems grow over the years

	agricultural information technology has entered to a new development era in terms of increased
	software packages, improved software quality, and extended application areas.
	Some conclusions can be drawn from the quantity growth:
	2.1
	Since 1990s, agricultural information technology has developed fast in China. Particularly since the
	beginning of 21st century, as agriculture development obtained strong national policy support,
	information technology in agricultural sectors has been greatly invested by central and local
	government which incentivized research and development. Therefore, it is a natural that the number of
	agricultural software of the agricultural research results increased greatly. Applications of the

2.2 Improved capacities in agricultural software research and development.

This research was supported by National Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China(2006BAD10A06,2006BAD10A12), Special Fund of Basic Scientific Research and Operation Foundation for Commonweal Scientific Research Institutes(2008J-1-06)


Jingyuan Liu
email: jingyuan@sina.com

Xiaoguang Ma

Zhihong Li

Xiaoying Wu

Nan Sun

Risk Analysis of Aedes triseriatus in China

Keywords: Medical vector, Risk Analysis, CLIMEX model, MaxEnt model, ArcGIS software, Model superposition

Introduction Introduction Introduction Introduction

The relevant laboratory study shows that conditions, A. triseriatus is a vector of several viruses such as yellow fever, eastern encephalitis, Venezuelan encephalitis and western encephalitis. It is also the vector of canine heartworm disease. A. triseriatus propagates in water, particularly accumulated water in treeholes and tires, and can also survive in artificial vessels where there is accumulated water, so the mosquito can survive in any place where accumulated water is available [2] . With increase in trade between China and North America, A. triseriatus is likely to invade China through cargoes, imported timbers and containers. It is a medical vector which may poses a serious threat to China. Therefore, it is imperative to predict the potential distribution scope of the mosquito in China with a view to preventing its invasion. A. triseriatus will colonization in an area is closely related to climatic factors such as temperature, humidity and rainfall, so the software CLIMEX based on the phenologic and climatic conditions is selected to predict its potential distribution in China. The software MaxEnt based on the maximum entropy algorithm is used to predict the possible spread areas of LAC encephalitis transmitted by A. triseriatus.

This paper provides s a risk analysis of A. triseriatus based on a superposition model.

Materials Materials Materials Materials and and and and methods methods methods methods

Materials Materials Materials Materials

Analysis Analysis Analysis Analysis of of of of limiting limiting limiting limiting factors factors factors factors for for for for distribution distribution distribution distribution of of of of Aedes Aedes Aedes Aedes triseriatus triseriatus triseriatus triseriatus :

The life cycle of A. triseriatus includes four stages: egg, larva, pupa, and adult. Adult A. triseriatus mosquitoes spawn on water surface and has one or two generations each year, depending on environmental conditions, especially rainfalls [2] . In Michigan of the US, the eggs hatch into larvae in March to April. There are four larval instars, and fourth instar larvae will moult into pupae. In northern states of the US, adult mosquitoes start appearing from mid-July to September. The eggs will enter a state of diapause under appropriate conditions, and in the southern US, this insect over-winters in mature diapause larvae. During diapause, larvae can move freely to seek foods, but non-diapause larvae move slowly and eat less. In Toronto, Canada, first instar larvae appear in mid-March, with water temperature at 4.1-9.7℃, second instar larvae start appearing in mid-April, and larvae start pupating in mid-May. Adults appear in June or July. The second-generation larvae appear in mid-July to mid-August, the secondgeneration population over-winters in larval stage before there life cycle ends [1] . Adult male mosquitoes appear earlier than female mosquitoes, and female mosquitoes start seeking foods 3 days after appearing. This mosquito prefers to bite mammals and is sensitive to light. The relevant study indicates that the photoperiod is a major factor that induces its overwintering diapause and a low-temperature environment can strengthen photoperiod induction [START_REF] Clay | Diapuase in Aedes triseriatus (Diptera: Culicidae) Larvae Terminated by Molting Hormones[END_REF] .The state of diapauses will end under long-lasting sunlight [START_REF] Baker | The effect of photoperiodism on resting, treehole, mosquito larvae[END_REF] . The photoperiod for inducing diapuase varies in different latitudes [START_REF] Donald | Egg diapause in Aedes Triseriatus (Diptera:Culicidae): geographic variation in photoperiodic response and factors influencing diapause termination[END_REF].

A. triseriatus has strong resistance to low temperature. In 1972, M Jail studied the influence of different gradients of temperature on its growth under laboratory conditions. The study pointed out that the temperature for the larvae of this mosquito to start growing normally is 9℃. In water below 4℃ or above 40℃, all A. triseriatus will die within 3 days. Under 6℃, 8℃ and 38℃, the larvae can grow to second instars, but will not continue growing. When the water temperature reaches 40℃, the larval mortality rate is still very high, with only 31% larvae survived. Obviously, high temperature limits its growth. In 2007, the study by Williams et al. in Canada stated that A. triseriatus might survive in southern Canada, and under natural conditions, it could spawn in water lower than 10℃ and first instar larvae were found in water of 0.7℃. Obviously, temperature is a main factor controlling the southern and northern boundary in distribution of A. triseriatus.

The eggs, larvae and pupae of A. triseriatus live in water and will not survive under overly dry environment. Strong rainfall will wash away A. triseriatus on water surface. Therefore, ambient humidity and rainfall limit its distribution to a certain extent.

Methods Methods Methods Methods

The data input in the CLIMEX model are biological data of eastern treehole mosquito including climatic factors such as temperature, humidity, illumination and stress. The model calculates the ecoclimatic index EI which reflects the probability of colonization of a species in a region. We can predict the probability of colonization of a species in a new habitat by adjusting the parameters so that the distribution of EI values maximally matches the present distribution of A. triseriatus. The inverse distance weight interpolation method of ArcGIS can carry out interpolation analysis of EI values to demonstrate more intuitionistically the potential distribution of A. triseriatus in China.

The MaxEnt model can calculate the survival requirements of LAC virus using environmental data based on its known distribution and the ecoenvironmental data. Known distribution data was listed as the input data according the published references. 80% of the input data was used to build the requested model, and the left 20% was used to modify it. Run the model to achieve the potential spreading scope of LAC in a new habitat. Space analysis of ArcGIS software was used to analyze the possible colonization of A. triseriatus if it is spread into China and the potential distribution scope of LAC virus transmitted by it in China, obtained the risk analysis result for A. triseriatus in China.

Result Result Result Result

Potential Potential Potential Potential distribution distribution distribution distribution result result result result of of of of A A A A . . . . triseriatus triseriatus triseriatus triseriatus in in in in China China China China

The preliminary parameters acquired according to biological data were adjusted match the existing distribution. The adjusted parameters are shown in the following table. Table Table 1 1 1 1

Table Table

. . . . : CLIMEX parameters of Aedes triseriatus

According to the adjusted parameters, the potential distribution of A. triseriatus in China was predicted. The interpolation result of ArcGIS was compared with the actual distribution in North America to carry out classification. The result shows that this Aedes mosquito is widely distributed in China, covering almost regions in our country. According to its distribution in North America, the EI values are divided into four risk levels: high, moderate, low and no risk. Among them, the EI value is above 30 and marked in red in the areas such as Yunnan, Guizhou, Chongqing, Guangxi, Guangdong, Hong Kong, Hainan, Hunan, Hubei, Jiangxi, Fujian, Zhejiang, Anhui, Jiangsu, Taiwan, east Liaoning, southeast Shandong, south Henan, south Shaanxi, southeast Sichuan and south Tibet. This indicates that there is a high risk of colonization of A. triseriatus in the above areas. The EI value is during 9-30 and marked in orange in the areas such as Heilongjiang, Jilin, Hebei, Shanxi, Liaoning, northeast Shandong, north Henan, north Shanxi, south Gansu, south Ningxia, northwest Sichuan, south Tibet, northeast Inner Mongolia, southeast Qinghai and northwest Xinjiang. This shows that there is a As the solely transmission of LAC virus and impossibility spreading without A. triseriatus , the vector insect and the host jointly contribute to the epidemic of LAC virus and decide the risk. Furthermore, during the risk superposition process, the vector's weight result is greater than the virus's weight result. The superposition matrix is shown in the following figure. Table Table 2 2 2 2

Table Table

. . . . Risk Matrix

According to the matrix analysis, the risks are divided into 4 grades and 13 levels by the vector weight superposition theory. The ArcGIS spatial analysis module is used to realize and demonstrate the above superimposition theory and gain the risk of spread of Aedes triseriatus into China (as shown in Fig. 3). The result is displayed in four color series: red, yellow, green and colorless, which presents the four risk levels high, moderate, low and no risk of A. triseriatus invasion respectively. Each color series is divided into four sublevels from dark to light, reflecting a high-tolow risk tendency in each level. Once A. triseriatus spreads to China, it will not only annoy people but also pose a threat to their health. In addition, this mosquito can be carried easily, and with increase in trade between China and North America, A. triseriatus is likely to be carried by trading tools such as ship, container. Therefore, it is necessary to formulate the relevant risk management measures according to the risk analysis result to protect people's health.

  of A. triseriatus in the above areas. The EI value is during 1-9 and marked in yellow in the areas such as North Tibet, central Qinghai, central Gansu, central Inner Mongolia, north Ningxia and northeast Xinjiang. This indicates that A. triseriatus can survive in the above areas and there is a risk of its colonization.

Fig. Fig.

  Fig. Fig. Fig. Fig. 1 1 1 1. . . . Potential distribution of Aedes triseriatus in China

Fig. Fig.

  Fig. Fig. Fig. Fig. 2 2 2 2. . . . Potential distribution of LaCrosse encephalitis in China 3.3 3.3 3.3 3.3 Result Result Result Result of of of of risk risk risk risk analysis analysis analysis analysis for for for for spread spread spread spread of of of of Aedes Aedes Aedes Aedes triseriatus triseriatus triseriatus triseriatus to to to to China China China China

Fig. Fig. Fig. Fig. 3 3 3 3 .

 3 Fig. Fig. Fig. Fig. 3 3 3 3. . . . Potential risk of Aedes triseriatus in China

5 5 5 5 .

 5 . . . References References References References[1] Williams D. D., Mackay S. E., Verdonschot R. C. M., et al. Natural and manipulated populations of the treehole mosquito, Ochlerotatus triseriatus, at its northernmost range limit in southern Ontario, Canada, Journal of Vector Ecology, 32(2): 328-335( 2007). [2] Penrod J. R.. Aedes triseriatus and treeholes: trophic interactions and factors influencing larval growth. Michigan states University, Michigan(2000).

.1.3 .1.3 .1.3 .1.3 Data Data Data Data

  The version number of the CLIMEX model is 2.0, and that of the MaxEnt model is 2.3, which can be downloaded directly via network (source website: http://www.cs.princeton.edu/~schapire/maxent/). The GIS analysis software is ESRI ArcGIS9.2. : The CLIMEX model has 2414 global meteorological stations including 86 Chinese stations, and meteorological data can be purchased from the Earth System Scientific Data Sharing Network (http: //www.geodata.cn/Portal/) according to the research needs to add Chinese meteorological stations. The environmental data necessity for the MaxEnt model is world eco-environmental data provided by Desktop GARP platform, including data such as elevation, climate and type of vegetation etc. The maps ArcGIS analysis come from the National Fundamental Geographic Information System (http://nfgis.nsdi.gov. cn/).

	2 2 2 2

2 2 2 2.1.2 .1.2 .1.2 .1.2 Model Model Model Model :

  The red areas with risk level of 44, 43, 42 and 41 represent high-risk areas. The risk level is 44 in deep red areas are highest risk level in the high-risk areas, such as east Liaoning, south Shandong, south Henan, Jiangsu, Anhui, Hubei, Hunan, Zhejiang, Jiangxi, Fujian, Guangdong, Guangxi, Chongqing, east Sichuan, Hainan and west Taiwan. The areas with the risk levels of 43, 42 and 41 mainly concentrate in Yunnan, central Sichuan, Guizhou and southeast Tibet. The yellow areas 34, 33, 32 and 31 represent moderate-risk areas, and the risk level is 34 in the areas with a comparatively high risk, such as south Shaanxi, south Shanxi, north Hunan, north Shandong, southeast Hebei, Beijing, Tianjin, northwest Liaoning, Jilin, Heilongjiang and southeast Tibet. The areas with risk level of 33, 32 and 31 concentrate in northeast Inner Mongolia, north Hebei, north Shanxi, north Shaanxi, south Gansu, northwest Sichuan, south Tibet and northwest Xinjiang. The green areas with risk level of 24, 23, 22 and 21 represent low-risk areas, and the risk level is 24 in areas with a comparatively high risk level, such as east Inner Mongolia, Beijing, Shanxi, Hebei and Shandong. The areas with risk level of 23, 22 and 21 mainly concentrate in north Tibet, south Qinghai, central Gansu, north Ningxia, central Inner Mongolia, north Shanxi and northeast Xinjiang. In the impossible surviving area of vector A. triseriatus, the risk superimposition result is 14, 13, 12 and 11 which can be regarded as at no risk because the vector cannot survive and the pathogen cannot be transmitted.

4. 4. 4. 4. Discussion Discussion Discussion Discussion In

  2005, Craig R Williams et al. used the CLIMEX model which is based on the biological climate theory to predict the potential distribution of culex tritaeniorhynchus which transmitted Japanese encephalitis virus (JEV) in Australia and New Zealand. The predicted distribution result of the mosquito is highly consistent with its actual distribution. This shows that the CLIMEX model can play a good role in predicting the potential distribution of organism vectors. However, the study did not carry out further analysis of the JEV carried by culex tritaeniorhynchus. Kurt D. Reed et al. had predicted the latent distribution areas of Blastomyces dermatitidis using the MaxEnt model. The study assessed the risk of LAC virus mainly transmitted by Aedes triseriatus using the MaxEnt model. The above two kinds of risk simulation results underwent superposition analysis based on the geographic information system and formed a new model for biological risk analysis of vectors.


Shipu Xu

Muhua Liu

Jingyin Zhao

Tao Yuan

Yunsheng Wang
email: wangyunsheng@saas.sh.cn

Research on Traceability System of Food Safety Based on PDF417 Two-Dimensional Bar Code

Keywords: Food source tracking, Food safety, B/S, Two-dimensional bar code

In this paper, through the research on two-dimensional bar codes of food source tracking; a set of traceability tracking system was designed based on the two bar coding algorithm and decoding algorithms. This system could generate PDF417 code based on food production, logistics and transport, supermarket and other storage information. Consumers could identify PDF417 code through a client based on B/S architecture so that a simple process of food traceability has been completed.

Introduction

In recent years, food safety is always a focus of governments, food companies, news media and the consumers, such as foreign BSE, GMF, domestic Melamine scandal, Sudan, etc. In 2009, the Food Safety Law adopted on Two Sessions shows the importance of food safety.

As more serious and emergent of food safety incidents were appeared, the concept of food traceability was mentioned once again. Food traceability is a process, in which the supply chains of participants take use of information technology to carry out the information sharing or to track food supply chains. Once a problem was discovered in some part of the food supply chains, we could find out the root of the problem using the information technology from downstream to upstream. There would be another relative word-traceability. It means that the system can provide backtracking mechanism at all possible steps, such as food growing period, breeding, processing, transportation and sale which involved in the process of products providing. So the consumers could decide what to buy according to this information related to the origin and transport. The application of backtracking mechanism was more mature and widespread in the EU and Japan than our country.

Currently, there are two popular traceability technologies in the world, including isotopes tracing and barcode technology. Isotope tracing technique is to distinguish various types of food and their possible sources, depending on isotopic composition in vivo of which is affected by the factors of climate, environment, and type of biological metabolism [START_REF] Mackay | Information Theory, Inference, and Learning Algorithms[END_REF] . The basic principle and foundation of this technique is based on the natural isotope fractionation effects. AS the information carrier, the bar code technology is a traceable method from downstream to upstream. This method is widely used in the world, and it also reached a certain high degree of maturity. Different types of bar code offered different origins of the principle.

In China, traceability of food safety technology develops late. There was only the concept of food traceability in the late 1970s, but it has a fairly rapid development. During the Tenth Five-Year Plan period, independent innovation capacity original innovation of food safety technology and recreation capacity of digestion and absorption are greatly enhanced through the implementation of food safety science and technology projects. In recent years, due to the repeated food safety problems, the government intensifies the monitoring of food safety but the work is just beginning. As the feature of decentralized management of food security monitoring, the uniform national food safety traceability system has not been established. The stage of research and simulation is presented in the sector, local department and company. At present, there is a relatively standard of food tracking and traceability technology which is introduced by the ANCC (Article Numbering Country Centre); but it has not carried out specific research on a particular aspect of the traceability technology. During Spring Festival of China in 2010, the two-dimensional bar code has a good use for security identification.

There has been 80 years since the bar code was invented. With the advance of technology, development of bar code is maturing and people's lives are more convenient. However, there is a separatist party because of the different characteristics in areas. Currently, bar code has more limited application which is only used in goods, logistics, library management, medical treatment and so on. Bar codes are different in different aspects. The same series of information cannot be shared between each other. The two-dimensional bar code which is emerging in these years can solve this problem well.

Coding of PDF417

As shown in Figure 1, each of PDF417 code includes 3~90 layers and each layer is composed by Start/End, Left/Right Row Indicator Code words and 1~30 symbol characters. Each symbol character is consisted of 17 modules, including the four black bars and four white bars [START_REF] Dermot | Kliebenstein Valuing Food Safety in Experimental Auction[END_REF] . As the number of layers and each symbolic in a layer is uncertain, the PDF417 can suit different needs.

As shown in Figure 1, the PDF417 code is composed by a symbol for each character which has four black bars (The black part in Figure 2, b1~b4) and four white bars (The white part in Figure 2,s1~s4). From the Start, each bars contains 1~6 modules from left to right. In a symbol character, there are a total of 17 modules in every bar. The PDF417 symbol set is formed by the three clusters. Each cluster contains 929 PDF417 codeword in different bars. In each cluster, each symbol corresponds to a unique code word characters which is ranging from 0 to 928.In PDF417, the symbol characters are used in cluster No.0, No.3 and No.6.PDF417 uses only one cluster on each layer of the symbol characters [START_REF] Johnston | Electronic Data Interchange using Two Dimensional Bar Code[END_REF] . The same clusters have a repeat in every 3 layers. Layer 1 uses the symbol character of the 0 cluster, Layer 2 uses the symbol character of the 3 cluster, Layer 3 uses the symbol character of the 6 cluster, and Layer 4 uses the symbol character of the 0 cluster, and so on.

The most important process which is taken by the mix of main text is translating data (character or ASCⅡ) into a symbol in coding with two-dimensional bar code. The corresponding relationship of data and text mode was stored in a database. Text code will be obtained through the corresponding to each character from a database. This text can generate PDF417 code word. The combination formula is C = 30 × H + L(C means code words and H and L means high and low characters in the corresponding character value respectively) [START_REF] Kumar | DNA Barcodes can distinguish species of Indian mosquitoes[END_REF] .

First, the algorithm flow chart of generated codeword is shown in Figure 3. As shown in Figure 3, it can calculate the required error-correcting code word according to the generated code and choose error correction level. The error correction code words generated according to Reed_Solomn algorithm, including the following three steps [START_REF] Itkin | A PDF417 Primer[END_REF] .

First, data polynomial symbol will be established. Its expression is d(x) = d n-1 x n-1 + d n-2 x n-2 + …+ d 1 x + d 0 .The coefficients of this polynomial contains a data code word which has a area code word, including the length of code word symbols, data code words and filled code words. The alignment of each data code words (d i ,i = 0,…n-1) in the bar code is shown in Table 1.

Table 1. The location diagram of data, row identifier, and error correction code words

Second, error-correcting code word generating polynomial will be established. The polynomial with k-generator for the codeword is: g(x) = (x-3) (x-3 2 )…(x-3 k ) = x k + g k-1 x k-1 + … + g 1 x + g 0.

Third, for a given set of data code words and a selected level of error correction, error correction code words will be generated.

Finally, it arranged in a matrix on which the request was encoded in accordance with the d n-1 , dn -2 ... d 0 , C k-1 , C k-2 ...C 1 , C 0 order. As shown in Table 1, the d n-1 =n means the number of data code word. The output encoding can be a text file. Each row in the file corresponds to each line of bar code, and each line is content from Table 1.With the calculated code word, it will be transformed into the corresponding 01 sequence for white and black bars through a piece. Such as 41111315, it will be compiled out of the 11110101111011111.

After completing these three steps, it will query symbol characters by the data word, Left/Right row indicator, error-correcting code word and each cluster of a line, and drawing a bar code in accordance with the code symbol character. It can be modeled on the one-dimensional bar code.

In the design of the traceability of food safety system, the process of encoding is to convert the readable information to a bar code character which is used to draw, and then the additional and related information can be added. The process of coding is shown in Figure 4. The original information which contains text, characters, numbers, images and fingerprints is converted to PDF417 bar code string. The code string is 929 for the domain of integers. After searching the database, it will be converted into symbol characters, and finally a two-dimensional bar code graphics will be drawn through the relevant procedures.

Designing of System

There are four design principles of this system: 1, Convenient and practical. The first principle of this platform design is convenient, simple to operate, and the system is easy to learn and use, thus it reduces the threshold for using this platform. To some extent, it avoids a difficult situation when promoting this system by the lack of technology.2 Science and reliability. The food safety traceability system makes full use of one-off data from research and market. It could ensured that the information provide is scientific, reliable to meet the needs of all users.3 Three-dimensional, cross and completely. The system uses the information dissemination chain with multiple, three-dimensional and cross.4, High security, high compatibility, easy to maintain and scalable. It ensures security of data backup and recovery automatically by using advanced technology. With a cross-platform technology, all the function modules of this system could be run normally in a variety of operating environment. Thus it could be easy to maintain and manage in later period, easy to upgrade, expand and improve.

As a widely used system, the system's designing goals and requirements, combination of advancement and practicability, and scalability need to be balanced. It can be considered from the following aspects of the system's logical designing. ① Make clear the construction goals and the user's needs of this system. In fact, the system can determine the goal of building phases. Only when the goal was clearly defined, we can determine the content and size of system construction.

And to formulate a reasonable and ordered solution is the key of success or failure of the system. ② In the choosing of 'advanced' and 'practicality', it does not blindly pursue the advancement in technology. It just tries its best to meet the needs of the user when the technology can be achieved. ③ Considering scalability. With the development of society, the progress of information technology and user needs can be changed; the system scalability is referred to a very high level, which requires the structure of rational planning system; and it should be set aside the interface with other systems. Based on the above considerations, the map of the system logic design and framework is shown in Figure 5. According to Figure 5, the logic design and framework map from the following three aspects to illustrate. ① The security and accuracy of core database data. In order to ensure this, the authority of a person who stored such information into production base, transport and supermarket is set to only increase data, but cannot modified and deleted the information. The authority permission is set to place the database on management who has the highest permission. In order to prevent the invasion of hackers and viruses, the interface of information input was designed to C/S structure which is the only way to guarantee data's security and accuracy. ② A major function of the system is bar code generation module based on C/S structure. The appropriate encoding algorithm of PDF417 two-dimensional bar code was selected in this system. It needs a special note that the PDF417 bar code's image should be saved as a picture into database in the background. ③ When PDF417 bar code is identified, there are two types of user groups. One of them is identified as the typical consumer. The convenience and fast of use is what they need mostly; so we choose the better algorithm of PDF417 bar code decoding which reflected in the error correction capability and time. Another type is identified as the user who has a special need, such as members with information at all levels and the secession makers in other departments. They need to draw more information on this PDF417 bar code and develop appropriate policies and regulations; so these users should require higher accuracy of the information. If necessary, such users can connect directly to the database.

Conclusion

This paper analyzed the current situation of food safety traceability at home and abroad; and the framework map and logic design of the system was released in this paper. The traceability of food safety in the promotion of the tracking system will be restricted by a number of hardware and the narrow use. In future, if the hardware was more mature, this system can be ported to the portable devices, such as mobile phones, PDA and other mobile devices. Under the mature 3G network, the consumer is convenient to use the system.

Fig. 2 .

 2 Fig.2. The schematic of symbol characters. In this chart, it contains a symbol for each character which has four black bars and four white bars.

Fig. 3 .

 3 Fig.3. The algorithm flow chart of generated codeword.

Fig. 4 .

 4 Fig.4. The flow chart of generating a PDF417 image. There are four statuses in this chart. At last, a picture could be output.

Fig. 5 .

 5 Fig.5. The map of system logic design and framework. There are three types of user in this system which contains administrator, special users and guest

Fig.1. The Schematic of PDF417. It contains start symbol and terminator, left and right level indicator.


Yeping Zhu

Yongsheng Cao

Multi-Agent Multi-Agent Multi-Agent Multi-Agent Quality Quality Quality Quality of of of of Bee Bee Bee Bee Products Products Products Products Traceability Traceability Traceability Traceability Model Model Model Model Based Based Based Based on on on on Roles Roles Roles Roles

Keywords:

Role is an important concept in research on how to develop method of Agent-Oriented software. In this paper, To study the background is bee product quality traceability system based on Multi-Agent, base on bee product quality critical control point, and describes a role-based multi-level framework of the method . Through Agent get different roles,and it get a group of services related to the process of quality of bee products tracing. At the same time, through the dynamic role change to realize the collaborative process between Agent management. Multi-Agent system model based on roles provide new methods and ideas about the control of the quality and safety of bee products.

storage, transportation, honey varieties, environmental pollution, pest control treatment, collection tools, acquisition time, equipment, sanitation, materials, health status, technical levels and so on. Each link exists between each other the exchange of information. Due to geographical differences (the management are widely distributed in different regions ), the time difference (there is a huge time difference about access to products, access to relevant information ), making information management has become very complicated.

From an engineering perspective, the bee product quality tracking and traceability system is a wide-area Internet-based technology and distributed artificial intelligence system. Agent technology can be used to solve the distributed system, it has many good features based on Agent and Multi-Agent technology application system, such as initiative, intelligence, interaction, collaboration and mobility and so on. Therefore, the quality of bee products tracking and traceability system can be decomposed as a dynamic system, no matter how large the scale, in theory, the system can be broken down into a number of interrelated sub-systems (such as acquisition system, processing systems, transport systems, marketing systems, etc.). There are also relatively independent subsystems in quality management in the actual work, the bee for the production, acquisition, processing, transportation and sales departments have the corresponding entities.

On the other hand, As a result of its own characteristics, Critical Control Point(such as pests and diseases, medication, heavy metals) play a very important role in the quality of bee products tracking and traceability system, the advantages and disadvantages of these entities directly related to the quality of bee products. These entities can completed their own tasks and goals to achieve optimal, they have independent thinking and ability to fulfill its mandate, they can cognitive state that all other entities of the current, and can accept the request and orders of other entities to change their behavior mechanism.

In this paper, a multi-agent cooperative module is proposed, that is a role-based dynamic multi-agent cooperative module. This module introduces a role concept into the multi-agent cooperative system. It rebuilds a library of role information in every agent, thus realizing multi-agent dynamic cooperation.

Role Role Role Role and and and and Binding Binding Binding Binding Mechanism Mechanism Mechanism Mechanism

In general, Agent for the operation of a common goal, each Agent must continually analyze their environment, and to interact with each Agent in a multi-agent systems. At any time, there is a number of different external stimulate and behaviors need it to decision-making, and require a lot of time and communication resources. No doubt that this complex multi-Agent Learning System. In this case, a good solution is to give each Agent to determine their respective roles, each Agent has its own characteristics, and collaboration with the Agent is dynamically generated, dynamic constraints, thereby reducing traffic, improving the efficiency of learning. Based on this thinking, the article proposes a role-based dynamic multi-agent collaboration system.

Role Role Role Role

Role concept from sociology, the basic point is limited to the role of individual behavior, the relationship between role limited the interaction between individuals in the system. In the study of multi-Agent systems, the role as a bridge connection with the micro-macro model, some researchers introduced the concept of the role of system analysis and design. In the multi-Agent system, to the role defined as follows [START_REF] Li | Intelligent and Cooperative Information Systems[END_REF] :

1. From the conceptual point of view, the role is a constraint. In this restriction, Agent involved in some of the interactions and evolution in some way.

2. From the implementation point of view, roles are some of the properties and behavior and binding on the Agent.

The current study suggests that the relationship between the role and Agent with the following typical properties:

1. Dynamic: In the Agent life cycle, we can add new role and undo the original role.

Dependence: role of the Agent can not exist independently, it must rely on an

Agent.

3. Multiplicity: the same Agent may assume different roles in the same period,and the same Agent may also take different roles in different times.

As the Agent may assume different roles and bring a different point of view , the Agent reflect more comprehensive and detailed knowledge.

Binding Binding Binding Binding Mechanism Mechanism Mechanism Mechanism

To coordinate the implementation of multiple Agent in the collaborative environment is a collaborative mission of the basic problems. In the Agent team, each Agent responsible for one or more role, through the dynamic transformation of role, the team can more effective implementation, in order to adapt to the environmental changes, to improve overall system performance. Agent role binding allows multiple Agent cooperative coordination in the implementation of tasks. In the multi-Agent system, it can take dynamic binding mechanism to achieve the transformation of role.

Role binding is divided into three types:

1. Role Assignment: Agent play a new role after it complete the current mission.

2. The role of redistribution: Agent interrupt the current role and play another role.

3. Role of the exchange: Two Agent exchange of role in the implementation. Each activity was defined as a single Agent in the process of traceability of the quality of bee products, the Agent has a role, and to collaborate and interact with other Agent. For example, buyer can be defined as the buyer Agent, the Agent role is to receive beekeepers request and respond, if agreed to acquire, the buyer Agent continue to process the request to processed Agent, and then processed Agent with other relevant Agent interaction. These Agent information exchange with the other Agent (such as beekeepers Agent, Sales Agent, etc.)through for communication interface, and then call the role-base specific role,analyse and process the exchange of information, thereby on exchange with the other Agent to respond. The exchange of information means that Agent of different task holders to the successful and satisfactory completion of an activity and exchange of information in the process of traceability of the quality of bee products. Behavior results is that the Agent based the role of the task, through the Agent exchange coordination with the requesting Agent, jointly with the other Agent to complete the activity behavior.

MAS MAS MAS MAS Model Model Model Model based based based based on on on on Role Role Role Role

The Agent through the role-base to describe it play the role, an Agent may have one or more roles , so the Model can adapt to changing roles in traceability of the quality of bee products system, strengthen the model agility and expansibility. For example, Processing Agent plays the role of the original honey production tasks, if the business process changes, the processing Agent in addition to played the original honey production tasks, coupled with the acquisition of the role of the buy honey, then just in the process the role-base Agent added to the original honey acquisition role, do not need to modify the traceability model.

There are many Agent in traceability of the quality of bee products system, but in order to facilitate the discussion, we put them into an abstract class for the 3 main: decision-making Agent, Management Agent, Operation Agent.

The The The The definition definition definition definition of of of of the the the the role role role role in in in in Agent Agent Agent Agent

Agent of social behavior is essential for building multi-Agent Collaboration model, the role of Agent behavior abstraction, reflected status and interaction in group (organization or society). So we must set up an appropriate role model to study the social of Agent.

In order to more fully and accurately reflect the role of the concepts, this paper defines the role model include obligation, authority, rule, activity, information, description.

1. Obligation is the role must fulfill obligations, it is the role in Agent assume tasks.

2. Authority is the role of responsibility for ensuring the realization, including the use of resources, access control permissions.

3. Rule is role must comply some norms, it also illustrates the role of supplementary obligations.

4. Activity is a group of private action about role, the implementation of these actions contribute to the role of its responsibilities. The so-called private action is implement these activities do not to involve interaction with other role. 5. Information is essential for each role domain knowledge and to help it achieve its role and function.

6. Description is the role of a conceptual description and introduction.

Role Role Role Role Dynamic Dynamic Dynamic Dynamic Transformation Transformation Transformation Transformation

The beginning of the process of traceability of the quality of bee products, systems based on the demand assigned role to Agent. Implementation process, Agent interact with others agent through its role of responsibility and authority, provide the appropriate services. But as the environment or demand changes, it was asked to provide more services, but also need some new services, Therefore, the role needs to be transformation.

In order to achieve Agent dynamic transformation role in collaborative activities, the paper proposes role assignment methods to dynamic transformation role. One the one hand, the role assignment methods confirm role eligibility verification and appointed about Agent, On the other hand, the realization of the role to create, modify, delete, and matching management. The current role of the Agent set for the Role-Old, new role of dynamic transformation role for the Role-New, it called the goal role, and RoleData is role-base.

Based on the above description, describe the Agent role transformation process is as follows: The problem of input, Agent initialization. The initial state, the system environment including user Agent, Management Agent.

1. user interaction Agent is the system and user interface, receiving user input of information, when the task is completed, the results displayed to the user. It create the role list base on the user information , and dissemination through the role bulletin board, and then wait for other Agent apply for the role. Now we assume the role list base included drug residues, processing technology, disease, three role notice. The problem solving though Agent of collaboration. 1. The system started when all roles in role bulletin board application by Agent.

Management

2. Due to the role of its "limitations", Agent not complete with its own functional role, such as Disease Agent running process, it need to generate better understanding of bee disease, its culture environmental information, but it is not ability to resolve, so the disease Agent apply to role bulletin board, on the one hand, it can join the existing operational environment to work together by generating new Agent (environmental Agent).On the other hand, completed Work Agent (such as: At this point, processing Agent has completed its mission in sleep state), according to "their" character (willingness) and the role-base functions, re-apply for new roles (environmental Agent) for system operation.

3. Management Agent real-time detection information in the role bulletin board in order to make the appropriate action (such as many Agent apply for a role, Agent work has been completed, etc.). The results of information integration.User interaction Agent get results to the user form a friendly man-machine interface. This cycle until the completion of the task.

With process management, supply chain management, value chain development and modern information and communication technology revolutionary. Traceability has been given more meaning. Traceability has evolved into a dynamic supply chain management and enterprise application integration based on the product track and trace, it become main tools about data management, process management, process control, decision support. Application of Agent technology, Users will need to find the information to inform Agent, and let it into the appropriate environment and collaboration and completion of treatment. Such as quality of bee products traceability system, it achieve an intelligent and automated so that consumers from tedious search for the goods, browse, compare, select and negotiate such links.

Therefore, it has important research value that Multi-Agent Quality of Bee Products Traceability Model Based on Roles.

Conclusion Conclusion Conclusion Conclusion

In this paper, multi-Agent system as a social organization, the tasks and objectives within the system is resolve the role, the Agent binding role to complete the mission and objectives. we achieve role transformation and collaboration based on role in this study, for further study of the relationship about Agent and role, roles and role relations and implementation mechanism.

3. 1 3

 1 Fig. Fig. Fig. Fig. 1 1 1 1. . . . Bee product quality traceability system Agent Model

Fig. Fig.

  Fig. Fig. Fig. Fig. 2 2 2 2. . . . Bee product quality traceability system architecture based on multi-level Framework

Fig. 3 .

 3 Fig. 3. Role Transformation

4 4 4 4

 4 Example Example Example Example* The first step:

  Agent is a shared communication area , at the same time, it responsible for the management and provision of resources. * The second step: The resolve of decision making. It has been in the environment of the Agent, inquiry into the environment role bulletin board, looking for own functions and resources to meet the requirements of the role and to determine the application for it own role. This time, Agent have a real function ( Role-based Agent), such as drug Agent, Processing Agent, Disease Agent. * The third step:

4 .

 4 The results of each Agent through Management Agent to user interaction Agent. * The fourth Step:

6.Acknowledgements 6 .

 6 Acknowledgements 6.Acknowledgements 6.Acknowledgements This research was supported by National Scientific and Technical Supporting Programs Funded by Ministry of Science and Technology of China (nyhyzx07-041). National Natural Science Foundation about Agent-based quality control of agricultural products(60972154).


Hailiang Zhang
email: hailiang.zhang@163.com

Jianmin Zhou

Xudong Sun

Yande Liu

Food safety and technological implications of Food Traceability Systems

Keywords: food traceability, quality, safety, technology

Food safety has become an important food quality attribute.Both food industry and authorities need to be able to trace back and to authenticate food products and raw materials used for food production to comply with legislation and to meet the food safety and food quality requirements. Traceability is increasingly becoming a necessary task in the food industry which is mainly driven by recent food crises and the consequent demands for transparency in the food chain. This is leading to the development of traceability concepts and technologies adapted to different food industry needs. The content of this paper include several aspects such as overseas food traceability system present conditions and development, food traceability system present conditions, problems and prospect in China, put forward the main measures of pushing on food traceability system of china.

Introduction

The demand for food traceability has significantly expanded in the last few years all over the world with increasing incidence of food-related safety hazards and scares such as footh-and-mouth disease, mad cow disease, microbial contamination of fresh produce, dioxin in poultry which greatly decline consumer confidence on food safety. There can be found several definitions for traceability, such as "the ability to follow the movement of a food through specified stages of production, processing and distribution" (Codex Alimentarius,2004), "the ability to trace the history, application or location of that which is under consideration" or "when considering a product, traceability can be related to the origin of materials and parts, the processing history, the distribution and location of the product after delivery"(International Standardization Organization (ISO)). The EU Regulation 178/2002 describes it as "the ability to trace and follow a food, feed, food-producing animal or substance intended to be, or expected to be incorporated into a food or feed, through all stages of production, processing and distribution".(E. Abad,2009) The term "food traceability" can be traced back to 1986, the year that the first case of mad-cow disease (Bovine Spongiform Encephalopathy, BSE) was reported in the UK. Four years later, the government of UK started a committee to survey the cause and origins of BSE, using the traceability system of cattle production, which is the embryonic form of the current food traceability system. Food traceability has placed responsibilities on producers, processors, caterers and other handlers in the supply chain to ensure food safety because foods are mostly composed of more than one ingredient and have often been composed of a series of processes. Raw material producers, ingredients/packaging suppliers, distributors, storage operators, retailers, points of sale, shops, and transporters are all relative partners of the food traceability system. Within the food industry, traceability implies the ability to trace and follow feed, food, and food producing through all stages of production, processing, and distribution. As a result, making a complete traceability system will need enormous resources and effort. Traceability is essential, particularly with raw materials, to establish that control procedures have been applied and are effective. There are good examples of where traceability has had a specific approach, e.g. beef labelling and genetically modified materials.(M. F Stringer,2007)Traceability systems can be considered as a bridge between producers and consumers, since the details of where the products come from and how they are marketed is available for those who are concerned.

Technological implications of Food Traceability Systems

Food traceability system is highly knowledgeintensive and increasingly information-driven. Technological innovations are necessary to reduce transaction costs and facilitate the production of top quality,safe and traceable products to meet consumer demands. Technological innovations are needed for product identification,process and environmental characterization, information capture, analysis, storage and transmission. These technologies include hardware (such as measuring equipment, identification tags and labels) and software (computer programmes and information systems).

2.1 food product identification technology: A major character of the food traceability system is the ability to trace-back the history and the physical location of the food products. To achieve these, accurate labeling is essential. The simplest technology to achieve this is to attach a tag to the surface of the food package and to transfer that data on the tag to the bar code of the food product (Figure 1).The use of computers and other information technologies have spurred the development of electronic identification (EID) systems, which include electronic tags with chips and scanners for reading, storing and transmitting the data to PCs for analysis and long-term storage. An important attribute of tags is that the materials must be resistant to rough handling and bad weather. Advancements in material science have led the development of tags that are resistant to tear which can withstand harsh environmental conditions.Innovations in geospatial science and technology such as radio frequency technology and mobile tracking devices have the potential for collecting and transmitting data from tags to distant locations for storage and analysis. 2 quality and safety measurement technology: the success of traceability is to meet the expectations of the consumer and other stakeholders, the ability to ascertain the location of the food product for effective recall in the event of food quality or safety breach. This requires accurate information on the maturity and quality attributes and safety status of the product, which must be measured and analyzed using appropriate instrument and procedures.

Product features such as size, firmness ,soluble solids, acidity, flavour, etc, are some of the physical, mechanical and chemical properties that may require measurement. Nondestructive tests based on force sensing, infrared and magnetic resonance imaging can also be used to measure firmness and other internal quality attributes(Linus U. Opara,2003).

2.3 genetic analysis technology: The need to preserve the identity of food product and the demand for genetic traceability have led to the development of procedures and measurement devices for the analysis of the genetic constitutions and contamination of foods and other biological products(Giese, J.H. 2001).

2.4 environmental monitoring technology: Environmental conditions such as data of temperature and relative humidity collecting,atmospheric composition of the air including pollutants and so on which impact on the quality stability and safety of food products.Instrumented environmental recording devices for monitoring these parameters are available(Linus U. Opara,2003) .environmental monitoring process is shown in Figure 2.

Figure 2. environmental monitoring process 2.5 evelopments in geospatial science and technology:

The integration of geographic information systems (GIS), remote sensing (RS) and global positioning systems (GPS) offers considerable opportunity for the derivation of data related to the food products. These technologies enable data to be remotely collected on a farm, which can be processed, transmitted and presented as product attributes. With respect to food traceability, a vital feature of these technologies is the possibility to map the geospatial variability of selected attributes such as yield, product quality(Bossler, J.D. 2001).

2.6 web and database technology for food traceability system: Web and database technology relies on the application of appropriate computer system, and which links the food traceability to a central database at the company, national or international level.(Figure .3) Food traceability systems require lots of data uploading to be saved as digital files. The growth in the use of personal computers, with immense processing power, and the continued development of the Internet provides an appropriate environment.The increasing speed and capability of the required communication hardware together with falling prices also contribute to the viability of such a system. Modern personal computers provide a simple means of connecting to the outside world, using software and hardware which are provided with the machine.The system makes use of Internet technology to implement a worldwide solution.It is the physical connectivity of the Internet, as well as the communication protocol (TCP/IP) that is used. The food traceability system can be quickly deployed anywhere in the world. This can be communicated directly to the database server.This process is automated and transparent to the user. After being verified by officially qualified institutions, agricultural food products are labeled with a traceable combination of numbers, just like IDs for foods. Purchasers who purchase goods with these labels can trust the products are officially guaranteed to be of safe and high quality. Terminals set at retail markets are the communication port of producers and consumers. Once the traceable label is scanned on the machine, the detailed traceable information will be showed on the terminal screen.

center database of food traceability system produce proces s data sale process data identity data base of food produce data administator Figure 3. Center database structure of food traceability system 2.7 RFID technology Tags, which contain an integrated circuit chip and antenna, are integrated into objects such that these objects can be identified and their label information can be read. Radio frequency identification involves detecting and identifying a tagged object via radio waves transmitting data from tags to a reader(Jung Lyu Jr.,2009). One of the greatest challenges of implementing food traceability system under certain circumstance lies in the fact that products distribution has a global covering, thus it becomes difficult to precisely trace goods movement throughout the distribution chain.There is a solution that could eliminate these difficulties -an automate gathering of data named radiofrequency identification RFID). Moreover, the RFID tag can store much more information than the linear bar code, and the information can be updated. Sometimes, solutions can be thought in order to combine bar code technology, RFID and vocal recognition, to create a flexible infrastructure which would optimally use the advantages of each technology. [START_REF] Goodrum | The application of active radio frequency identification technology for tool tracking on construction job sites[END_REF]Kwon & Choi, 2008).RFID technology allows the storing of information about all the products that have circulated in a certain container. This type of traceability is very useful for retailers, who can easily locate where to find a certain product, for a rapid delivery.With the help of the RFID tags, a supplier of fresh products (fruit and vegetables, for example) can trace where the goods have been delivered in order to accelerate the payment, or a retailer can be sure that the products are on shelves in the order they were stocked.

overseas food traceability system present conditions and development

As knowledge and economic grow, the people in developed countries are more concerned about quality and safety of food. Food traceability system is considered as a risk management tool for food safety and is widespread in developed countries such as Japan, the U.S.,Canada and many countries in the European Union. Food traceability systems can provide clear, correct sources and marketing routes of food products. With an integrated food traceability system, the government can recall the products immediately and limit the possible loss.In December 2003, the United States developed the statutes of tracking food safety,"Farm Security and Rural Investment Act"requires country of origin labeling for many kinds of food, including perishable agricultural commodities,which required all enterprises involved in food transportation, distribution and import recording their trade information for tracking and tracing back. In addition, the United States also plans to include 70 percent of the cattle in the NAIS (National Animal Identity System) project at the end of 2009. The European Union adopted mandatory traceability actions in food industry since 1st January 2005, Regulation No. 178/2002 establishes that food business operators must label adequately food, in order to facilitate the traceability(Official Journal of the European Union,2002). The Marche Region (Italy) project called SiTRA, aiming to provide food chain stakeholders with a Web platform managing traceability for the main regional food products. Consumers can identify the SiTRA traced products by means a Regional Brand (QM Quality guaranteed by Marche) embedded in the product label, reporting the traceability code to access the Web for traceability information of the product. SITRA platform is currently tracing 8 large food chains (fresh milk, bread, pasta, fresh fish, olive oil,wine, pigs and cattle) all over the Region. In June 2002, the Canadian federal government established an ambitious goal that, before 2008, the country would achieve tracing back 80 percent of agricultural products to its source, supporting the "Brand Canada strategy", of which a mandatory identification system for cattle and beef on July 1, 2002 came into operation. Japan was the first country to introduce a food traceability system in Asia. Due to the occurrence of a series of food safety events, the Japanese government raised food traceability system promotion to the list of important administration policies of Prime Minister Koizumi and expected to accomplish 50% implementation of food traceability in 2007 and 100% by the year 2010.Since 2001, the Japanese government has been promoting the development and use of food traceability systems,and the integration of traceability systems with agricultural risk management systems in order to improve food safety amongst food operators such as producers (farmers), retailers, and manufacturers (Nanseki and Yokoyama, 2008). The supply chain networks for the food industry are reacting both to global trends and to the changes brought about by the continued expansion and ever-deeper integration of the European Union. [START_REF] Ferrer | European supply chain management characteristics and challenges. Ascet achieving supply chain excellence through technology[END_REF] hold the opinion that the drive to unity is strong, but the diversity of competitive practices, labour laws, and regulations across Europe different countries and regions is rich. The supply chain winners will be those who can continue to create new opportunities through the implementation of optimised networks and the development of collaborative partnerships across their extended enterprises. ( Ingrid Hunt,2005)

food traceability system present conditions in China

3.1 present conditions It is highly necessary for China to establish traceability systems. For concerning about both domestic food safety and international trade, since 2000 China has been adopting lots of measures and programs to introduce, extend, encourage and even mandate traceability system in food supply chain. In legislation, there are a few specific laws or regulations concerning food safety but little referring traceability before 2001. There have been numerous food contamination events and animal diseases like avian-influenza, foot-and-mouth disease, bad duck eggs and event of milk in recent years, causing extensive panic among the populace and tremendous losses to the farmers of China. Regarding on substantial advantages such as reducing marketing costs, ensuring product integrity, increasing consumer confidence, China is now developing and implementing food traceability programs throughout (Ministry of Commence of China, 2006). Provide visibility of China's food safety and quality systems to consumers, importers and governments of world, as well as to domestic businesses and consumers. Enhance the user's confidence on the safety of materials, raw materials and products from China. In order to ensure food safety, Beijing had established a specialized food safety traceability system for the 2008 Olympics, in order to monitor food quality from the origin of production to each stage of processing, packaging, transportation,distribution till ultimate consumption.The Beijing Administration for Industry and Commerce (BAIC) and Beijing Food Safety Supervision Office (BFSSO) already founded Beijing Food Safety Traceability System (henceforth BFSTS) based on Capital Food Safety Monitoring System (CFSMS) under the network environment of BAIC. BFSTS consists of one first-level platform and four individual subsystems.The first-level platform is that Beijing Data Centre for food safety traceability, which is responsible for information collection, analysis, evaluation, tracing, early-alarming.The four sub-systems includes fruit and vegetable,animal products, prepackaged food and Olympic food traceability sub-system. One survey in city markets and rural markets performed in 2006 by Ministry of Commence of China showed that 53.7% of city markets, 32% of supermarkets, 80.4% of wholesale markets of agricultural products, 70.7% of retail markets introduced the above initial measures to foster traceability (Ministry of Commence of China, 2006). More than half of frozen food had already been able to be traced back to origin in 2008. In April 2004, the State Food and Drug Administration and other departments chose meat industry as a pilot industry, started meat and meat products traceability institution construction and system implementation (General Administration of Quality Supervision. 2002). The main tasks include: developing suitable technical standards and Management norms, publishing guidelines for implementing traceability system including "Meat products tracking and tracing Guide" and "Fresh product tracking and tracing Guide". In June 2004, Administration of national barcode management promoting investigated on vegetable products traceability and started an application project on two vegetable production bases located in Shouguang and Luocheng respectively in Shandong province. The project was successful in food quality control in the origin and enforcing standards of market access, product identification and recall. Integrated with electronic auctions and E-commerce, this project established a traceability system for pollution-free vegetables. Shanghai Livestock Bureau legislated to build digital archives for pigs, cattle, sheep, and the residents can now get access to the egg production information through internet. In August 2008, Beijing had already enforced a food traceability system along the full supply chain for the food supplied for Olympic games to secure food quality and safety. According to the law of People's Republic of China on food products' safe quality issued in 2006, all agricultural enterprises must set up production recording that should be authentic and be kept for at least 2 years; otherwise, the transgressor will be penalized not more than 5000 RMB. In addition, individual producers are also encouraged to keep recording within their own production. Such actions are considered as the rudiments of food traceability system in China. On June 26 of 2006, Ministry of Agriculture of China (MOA) promulgated the regulation on animal labeling and their feeding documents establishment in farms (No. 67 Act).In this act, the most key points are as follows: animals such as swine, cattle and sheep/goats in the farms must be gained unique identity code around the China, and it shall be labeled with a special tag embodying a unique code before moved from its region of origin. The feeding enterprises must establish their feeding information documents to record inputs mainly used,such as feeds, feed additives and veterinary drugs as treatment. Traceability on food-produced animals will be started in case of any of the following issues: (a) Some labeling are not in accord with livestock and products from themselves; (b) Livestock and their products have been infected or contaminated by some diseases and virus; (c) There is no quarantine certificate authorized by the accredited institution; (d) Some veterinary drugs and other venomous substance have been used, which are forbidden in terms of related regulations; (e) when serious animal health events occurred; and (f) other situations in which traceability should be applied.

3.2 Problems and measure of pushing on food traceability system of china Promoting food traceability systems among consumers should focus on obtaining recognition from consumers. Being unfamiliar with this new concept in china, the public may consider "traceability" only as a commercial term, which makes no difference whether the products are traceable or not. Since most consumers don't understand the principle and value of food traceability systems, the Chinese government should endeavor to educate the public on the concept of food safety and possible food contamination routes. Once the public recognize that the food traceability system is a possible solution which can prevent certain problems and ensure their health, they will be interested in traceable food products and be willing to purchase the traceable agricultural products at a higher price. Recent theoretical literatures provide some useful information relevant to analyzing different consumers' increasing concerns about food quality and safety knowledge and the effect on food choices. Some studies about consumers show knowledge about food safety tends to increase with age, level of education,and experience in food preparation. These research findings are useful to assist in research of Chinese consumers' perception toward quality and safety of safe products(Wang Feng, Zhang Jian,2009). The basis of the traceability system is the detailed data recorded by the producers. In the early days of promotion in China, most of the farmers didn't consider the traceability system as a constructive policy but rather a complicated and inconvenient one. From their viewpoint, the consumers would not care about the traceable records; the policy was considered just a waste of effort and time. Besides, some older farmers are not educated as well as the young; so even the ordinary paper records are huge obstacles for them, not to mention electronic documents. For companies, compliance to legislation is recognized as the major driving force towards introducing a quality supervision and traceability system. Value added to products through increased consumer confidence may be another important reason. The government should start to educate the producers about the advantages of implementing food traceability systems, popularizing the concept of food safety, making them believe that this could be a wonderful resource with full cooperation and could lead to a more profitable career. The endorsement from consumer to food traceability system is the biggest strength of promotion.Food safety and quality, rather than price, is considered the most important factor affecting food product purchasing decisions of Chinese consumers [START_REF] Zhang | Consumption trends and habits for fishery products in China[END_REF]. Once the consumers agree and favor the traceable products, the rise in profits will bring confidence to the producers. Through mutual trust established via food traceability systems, the benefits of both the producers and the consumers can be ensured. Therefore, food traceability systems can be considered as an investment which gives farmers profitable and stable business, and safe food for the public, leading to a promising future for sustainable agriculture.

conclusion

The emergence of food traceability system is the result of developments in improving food quality and safety management. Farmers, processors and handlers, and food policy experts need to be aware of future developments in this area to assist them in implementing food traceability systems for their enterprises. The methods for data capture, data exchange, data storage and the integration of the traceable supply chain are essential for the success of food traceability system. The traceability system of food products, including fish, poultry and meat products, means that the information of a product, from producing and processing to marketing, is recorded and can be traced, "from farm to fork". If all the food products are implanted with traceability, the consumer can not only query detailed information about the food but also secure themselves from impairment by checking suspicious process in the food supply chain through the food traceability system.

Figure 1 .

 1 Figure 1. Bar code of the food product 2.2 quality and safety measurement technology: the success of traceability is to meet the expectations of the consumer and other stakeholders, the ability to ascertain the location of the food product for effective recall in the event of food quality or safety breach. This requires accurate information on the maturity and quality attributes and safety status of the product, which must be measured and analyzed using appropriate instrument and procedures.Product features such as size, firmness ,soluble solids, acidity, flavour, etc, are some of the physical, mechanical and chemical properties that may require measurement. Nondestructive tests based on force sensing, infrared and magnetic resonance imaging can also be used to measure firmness and other internal quality attributes(Linus U. Opara,2003).2.3 genetic analysis technology:The need to preserve the identity of food product and the demand for genetic traceability have led to the development of procedures and measurement devices for the analysis of the genetic constitutions and contamination of foods and other biological products(Giese, J.H. 2001).2.4 environmental monitoring technology: Environmental conditions such as data of temperature and relative humidity collecting,atmospheric composition of the air including pollutants and so on which impact on the quality stability and safety of food products.Instrumented environmental recording devices for monitoring these parameters are available(Linus U.Opara,2003) .environmental monitoring process is shown in Figure2.

ACKOWLEDGEMENT

The authors gratefully acknowledge the financial support provided by Natural Science Foundation of Jiangxi province(2009GQS0012,2009AE01603),International scientific and technological cooperation projects of Jiangxi Province (2009BHC00300,2009BHB15200),Youth Natural Science Foundation of Jiangxi province Office of Education (Grant No.GJJ10139).