Jia Zhao

Jianfei Wang

Wenjie Feng

Research and Exploration of Rural and Agricultural Information Service -Taking Shandong Province as a Case

Keywords: Rural and agricultural, Information service, Research and explore

Rural and agricultural information service is the fundamental condition for agricultural information development. Moreover, it is a effective way to narrow the effectiveness of the "digital divide" and integrate the urban and rural development. In this study, taking Shandong Province as an example, the service platform, service tools, service support and service teams etc are described. And, the rural agricultural information service model based on "Service platform as the core, service means as basic, service carrier as link, service team as support and public and market integration" is put forward in this study. This rural agricultural information service model is benefit for the agricultural information; accelerate the pace of rural agricultural information construction.

Introduction

With the accelerating rural agricultural informationization development, rural and agricultural information has led to support the direction of the transformation and upgrading of China's modern agriculture, and finally for the purpose of the application of information and services, and continuous ly infiltration. Rural agriculture information service is knowledge-intensive services of the integration of knowledge, intelligence, technology, information and funds in the foundation of the abundant information resources, convenient information network and modern information technology, which has the characteristics of wide demand, fast growth, high efficiency, energy saving, pollution-free, etc. Only by constantly sum up experience, explore new problems , new trends, new modes and new mechanisms of providing information services for rural and agricultural under the new situation, only continuous innovation, and to achieve better Agricultural information.

As a big agriculture province, Shandong province highly pay attention to the rural agricultural informatization work, and has been developing rapidly in the aspect of infrastructure, information resources, demonstration, application and service system construction etc. In 2010, Shandong province , in 2010 , Shandong province positively research and explore rural agricultural information service, solve the problem of the last kilometer of information service,effectively narrow the gap between urban and rural informatization development, thus was approved as the first batch rural agricultural informatization demonstration province pilot provinces jointly by national ministry of science and technology, the Organization Department of the Central Committee of the CPC, ministry of industry and information. Take Shandong province as an example to explore. After many years of the development in the leading mode of the government, rural agricultural information service gradually move towards to the parallel of public service and market service, rounded by different types user's needs, thus produced a large number of different forms and contents of information service organization, rural agricultural information service industry has been established. Which is mainly includes the service platform, service means, service carrier, service team, etc.

Rural and agricultural information service platform

Construction ideas

To build a platform with Shandong features, industrial service focus on "the integration of resources" and "efficient service" "mechanism to explore" and other key nodes to break through and innovation. Accordance with the "platform shift" principle, all kinds of information resources integration and development of agriculture in rural areas are carried out, meanwhile, effective cohesion with advantage industry professional information service system and basic information service station is stressed. So that, the "low cost, convenient" service information villages and households are speeded up, personalized information needs of farmers are satisfied, and new rural construction and development of modern agriculture is serviced.

Platform overview

Service platform relies on provincial party distance education network, and the development focus on ten content area and top ten industrial information service system. Scientific classification of column plate design is based on information services on websites. The columns and thematic of platform includes agricultural production, competitive industries, wisdom agriculture, commerce, village area, primary site, distance education, typical applications, convenience services. The platform named Qilu agricultural science and technology network(www.qlsn.cn) has been initially built and run, , which provides service interfaces for various application systems taking advantages of real time and large capacity of the Internet. This platform becomes mainly rural agricultural information service window of Shandong Province.

Rural and agricultural information service means

Hotline service

12396,which is jointly promoted by the Ministry of science and technology, industry and information technology, is the unified agricultural science and technology information service number. Shandong Province in December 2008 opened "12396" service hotline。 Fixed and mobile telephone farmers live in any areas of Shandong could consult to the experts by calling 12396, and only need to pay the ordinary telephone costs. It's effective to solve the problem that farmers have difficulty to use agriculture technology for a long time. However, with the development of science and technology, the traditional hotline service has been far from meeting the needs of farmers for information. We have merged the hotline and radio broadcast through coupler used multimedia speech fusion technology by making full use of 12396 hotline at the beginning of 2013. We are jointly with the Shandong radio and television broadcast channels to create the 12396 green voice in the inter broadcast. Farmers can participate in modern country live program by dialing 12396 after dialing 9. We have changed the traditional pattern one to one into one to N by strengthening the interaction between the host and the experts and the audience, and disseminated the knowledge of agriculture and technology to millions of households directly. At the same time, variety kinds of ways, such as microchannel, microblog, QQ group, were set to connect farmers and experts, to connect farmers and markets, to connect farmers and government.

Computer remote video service

Video conference system, which was consider as the important application of interactive audio and video communication, is becoming more and more widely used with the development of computer communication network and audio and video coding and decoding technology. Combined efficient H.264/AVC video encoding algorithm and high level meeting of GIPS voice engine, the remote video conferencing system has many advantages, such as excellent video quality, high level of automatic echo suppression, automatic gain control, Mike volume automatic adjustment, noise suppression and so on. The B/S structure, advanced video encoding and transmission were adopted in this system. The remote video services with a low bandwidth clear and smooth image was achieved through the Internet. The farmer could land the system and connect the video anywhere after get the ID. The software of system server-side is installed on the specialized video server of Service Platform which accessing to internet through 100M fiber, installation and distribution process of the software is simple, and it is easy to use. It can achieve instant communications, people meeting, conference recording, file sharing and other functions after installation and it provide services through many ways, like experts agents, booking agents, emergency relief, teleconferencing, training, etc.

TV set-top box service

Customers use IPTV and remote control to synchronize browsing Qilu Agriculture network information, demand agricultural science and technology video, implement web surfing by "TV + set-top box" approach. Currently, IPTV provides expert auditorium, live television, information services, agricultural science and technology, industries, commerce, web surfing and other columns.

Cellphone service

Mobile Client Service provide more timely targeted services, like policies and regulations, entrepreneurial wealth, rural alerts, agricultural science and technology, market, encyclopedias and other information services. Currently, Qilu rural integrated information services client, agricultural facilities things monitoring application client (Shed commander, pigs commander, chickens commander), Shandong Leisure Agricultural Services client, Prices for Agricultural courier client, mobile video client. Not only the farmers can directly scan two-dimensional code to download the client by log Qilu three rural network client download interface, but they can also directly download the client from the Android, Apple Store client. Mobile Video Services, the customer can get online video support via phone video by download client. The famer can achieve two-way communication using mobile phone through the video system. Farmers can consult various types of agriculture-related information, ask experts for a prescription for the pest, keep abreast of the latest agricultural information and solve problems which they encounter in agricultural production faster, and all above this greatly improve the efficiency and quality of the solving of various types agriculture problem.

Rural and agricultural information service carrier

Basic information service station is an important carrier of rural and agricultural information service, and meanwhile, it is a window to understand the platform information and accept the information service for grassroots organization, agricultural enterprises and farmers. The basic information service stations achieve flat information service with a direct connection with the serviceplatform to and the effective docking with the majority of farmers.

Construction standards

Basic information service station constructions need to meet the following requirements and standards, namely: a fixed place, a set of information equipment, an information technology correspondent, a set of training system, a set of management system and a long-term mechanism, mainly divide into two major categories of professional information service stations and integrated information service stations. As the important link of service platform and farmers, professional information service stations mainly relying on the existing levels of agricultural science and Technology Park, agricultural leading enterprises, professional cooperative organizations, professional associations, large breeding, agricultural capital construction management entity, are a necessary part of the whole rural agricultural information service chain. The integrated information service stations are the effective measures to promote the information to villages and households. Furthermore, it is an important part of rural and agricultural informatization construction. On the existing party members and cadres of modern distance education based on the grassroots service station, to select the service station with better hardware condition, staff members and facilities.To encourage the combination of public service and paid services in basic information service station, and the integrated services of technology, material and information, exploring a long-term mechanism to combine the public welfare and market.

Site administration

According to the actual needs of the grassroots information service station, the service platform is designed to set up the "grassroots" structure and the contents of the plate, including member account management, site registration information, site information management and other functional modules. Through the member account management module, the system administrator can view and review the member's personal information. In the site registration information module, the system administrator can query, preview, approval of the site registration information submitted by the member, in the "information management" module, the system administrator can query, review the information submitted by the members of the site, the audit, withdrawal and other operations.

Service models

According to local characteristics, the main models of information service stations was explored, such as agricultural technology station for technical guidance, agricultural materials sales department of information and material combination, the leading enterprises for leading-led, demonstration park for radiated and proceed, farmers' cooperatives organization for the market growth. In the promotion process, gradually formed a "integrated" service mode, and insisted on multi-pronged, multi-policy, so that the information spreaded to village and farmer to increase information efficiency.

Rural and agricultural information service team

The construction of rural agricultural information service team mainly includes operation team construction, promotion team construction and specialist team construction. Operation team construction mainly rely on the scientific research institutions, public welfare operation team construction consisted by government departments and marketization operation team consisted by professional company. Promotion team construction includes basic science and technology information officer, distance education information officer and primary agricultural technology personnel and strengthens the technical training and support for the messenger of information service station. Specialist team construction consists of not only the authoritative experts come from the institutions of higher learning and scientific research institutes, but also the technology experts who have practice experiences and can solve practical problems. These experts who are responsible for technical guidance covers the fields of planting, breeding technology, storage processing, pest control, construction of modern agriculture and so on.

the effect on rural and agricultural information service

As the foothold of agricultural informatization, the rural and agricultural information service to grow out of nothing, by weakly to the process which is strong, is experiencing a long development period. At present, the rural and agricultural information service is accelerating the coverage of penetration, the changes from heavy construction to heavy service, from single service to integrated services, from passive service to interactive services are happening. Through continuous exploration and summary, the rural agricultural information service is more mature following the thinking "giving priority to public welfare, the market as supplement, and The market in turn auxiliary public welfare". Fully integrated and use the existing information resources, and taking the service platform as the core, the service carrier as a link and service team as the support, on the basis of service means, improving the level and ability of public service, at the same time, actively exploring the market service mechanism, accelerates the low cost and high efficiency dissemination of information in vast rural areas, and to realize the zero connection between farmers and information.

Acknowledgment

This work was supported by the National Science and Technology Support Program (2014BAD08B05-02), the Shandong Academy of Agricultural Sciences Youth Scientific Research Fund Project (2014QNM25).


Wenjie Feng

Lei Wang

Jia Zhao

Huaijun Ruan

Research on Agricultural Development Based on "Internet +"

Keywords: internet +, internet of things, agricultural information

Agricultural modernization is an important way to construct modern agriculture. The development of intelligent terminal, mobile internet, communication technology, internet of things is being applied to agricultural production. It will greatly improve the level and degree of agricultural informatization, promote agricultural informatization development, improve agricultural production efficiency and improve agricultural production efficiency and promote the development of agricultural information technology and new technology.

Introduction

"Internet +" is to use the Internet thinking, Internet technology to promote the development of various industries and the transformation and upgrading, regardless of which kind of traditional industries, there is the opportunity to "Internet +", in the process, the core is the internet. China's agricultural development is lagging behind the industry, the government has introduced many documents to promote agricultural reform, mobile Internet communication technology in rural applications is also becoming more and more extensive, agricultural information is also changing the whole process of agricultural industry, and promote the optimization and upgrading of the industrial chain.

2

The internet + to provide a new platform "Internet +" is to use the Internet thinking, Internet technology to promote the development of various industries and the transformation and upgrading, regardless of which kind of traditional industries, there is the opportunity to "Internet +", in the process, the core is the internet. China's agricultural development is lagging behind the industry, the government has introduced many documents to promote agricultural reform, mobile Internet communication technology in rural applications is also becoming more and more extensive, agricultural information is also changing the whole process of agricultural industry, and promote the optimization and upgrading of the industrial chain.

Internet industry is the symbol of the Internet technology, business model, organizational approach to become the standard configuration of various industries. Three key technologies: ubiquitous terminal applications, an unprecedented strong background cloud computing capabilities, and continuously upgrade the broadband network constitutes the basis of the industry internet. The core competitive advantage of the relevant enterprise is the lower cost of the sensor, data storage and faster data analysis capabilities, the intelligent machine, big data analysis and other fields have accumulated and in-depth study of the enterprise will get a good opportunity for development.

China's broadband construction has made great progress in 2013, the State Council issued the "broadband China" strategy and implementation plan, proposed broadband network to become the new era of China's economic and social development of strategic public infrastructure, accelerate the rapid and healthy development of broadband infrastructure, and increase the speed of access to rural households, rural broadband access. In the next few years, rural areas will become the main source of Internet users in China, the mobile phone has become the main platform for the popularization of the Internet and the realization of the information technology.

The Internet into China 20 years, profound changes bring a full range of economic development, agriculture, transportation, energy, integrated into the health and education industries, has accumulated to a touch of Fayin burst change time, the Internet has become a new force on behalf of the engine of economic development and innovation driven development. The future, things will connect everything, O2O accelerated to open a new business model, industry cross-border cooperation will continue to innovate, to consumer Internet Internet industry migration evolution, the Internet will deconstruct each industry, stimulating industrial upgrading, the characteristics of almost all industries will present the pan internet.

3

The main problems of agricultural development

In recent years, with the rapid development of our economy and the improvement of people's life, the domestic demand for food is becoming more and more diversified, and other aspects of the food industry is also increasing. A lot of changes in the supply and demand, the price of food imports increased rapidly in 2014, China's domestic demand for soybean 87 million tons, of which 75 million tons, 11 million tons of soybean consumption of about 80% tons, of which 14 million tons, 4 million tons of domestic output, 6 million 400 thousand tons of cotton consumption, the output is 1 million 300 thousand tons, imports accounted for 20% of domestic consumption, the comprehensive grain self-sufficiency rate has exceeded 95%. According to the "national food security needs of long-term planning outline" forecast that by 2020 China's grain gap may reach 32 million 500 thousand tons.

On imports of soybeans and other staple agricultural products, the high degree of dependence of imported food sources are too centralized, constitutes a serious threat to food security in china. In addition, grain production in China is still faced with many negative factors: the scarcity of water resources threaten agricultural irrigation; rapid growth in labor costs against the enthusiasm of farmers; yield slow growth; bijiexiaoying caused grain acreage to expand the limited development of agricultural production mode; lag; land pollution problems resulting in food production and crops has reached alarming proportions. According to research report released by the Chinese Academy of Sciences Institute of ecology in 2012, China is currently subject to cadmium, arsenic, chromium, lead and other heavy metal contaminated land area of nearly 20 million hectares. In January 6, 2015, the Ministry of Agriculture said China will start a staple potato strategy, not China is the food safety problem of choice under the grim situation.

With the continuous improvement of the degree of external dependence of agricultural products, the area of cultivated land is gradually decreasing, and the situation of the people and the land is much worse. According to the World Bank statistics, in 2014 China's agricultural population accounted for as high as 45.6% of the total population, while the proportion of agricultural population in developed countries is generally low, such as the United States only 18.6% of the population engaged in agricultural production. With that, the average per capita arable land area of China in 2014 is only 0.22 hectares, which is lower than the level of 1.1 hectares in the United States, even lower than the world average of 65.2 hectares.

The agricultural population continued to decrease and the phenomenon of aging is obvious in recent 10 years, with the rapid development of industrialization and urbanization and the difference between urban and rural infrastructure and social life, rural youth are flocking to the cities (towns), the younger generation is no longer willing to engage in agricultural production, the proportion of working age population is declining, the age structure of agricultural population is gradually changing with the aging population. According to the National Bureau of statistics released the "2013 national migrant workers monitoring survey report" shows that in 2013 the new generation of migrant workers (1980 and after the birth of) a total of 125 million 280 thousand people, accounting for 46.6% of the total migrant workers, accounting for 1980 and the proportion of rural workers born after 65.5%. In the statistical period, 87.3% of the new generation of migrant workers not engaged in any agricultural production, most of the main working away from home. "Migrant workers" heat has not been back, plus the emergence of China's demographic dividend turning point, the agricultural labor force in particular, to continue to reduce the age of school-age.

The development of rural economy has stalled and the improvement of production efficiency has become more and more slowly. Since 1997, the average annual growth rate of agricultural added value was only 6.88%, far below the 12.45% growth rate of industrial growth and 14.21% of service industry. And this is a relatively high proportion of rural labor and the lower agricultural production efficiency, the 2013 end of the total employment of agricultural population in China, and the proportion of the total employment population reached 34.8%, while in 2011, only 1.2% in the United Kingdom, Japan in 1990 has only 5.9%. From the perspective of income, rural residents in 2013, the first time beyond the income of household management, accounting for 45.2%, compared to the display of income, rural household management does not have the advantage. Agriculture needs to reform, and vigorously improve the level of agricultural intensification, in order to improve the efficiency of rural areas and farmers' income levels.

The comprehensive reform of agricultural development

With the development of land circulation and scale management, the new business entities such as cooperatives, family farms, and major industries are rapidly formed, which correspond to the emerging market players. The agricultural information industry is developing rapidly, and the modern agricultural products circulation, which is the representative of electronic commerce.

Land system reform

In November 2014, the central office of the State Council issued "on the guide of rural land management rights orderly transfer of agricultural scale operation and development of opinions", documents based on register right, ownership, contract rights, management rights division of powers, to guide the orderly transfer of land management rights, the development of various forms of moderate scale management. Land transfer reform is the important part of the reform, the reform of state-owned enterprises, the important part of comprehensive deepening reform. Three right separation (ownership, contract rights, management rights) is a major practice of agricultural reform, China's rural areas are facing unprecedented a comprehensive reform.

Business subject reform

Cultivate new agricultural business entities is the basis of the development of modern agriculture. Under the background of industrialization and new urbanization, the rural labor force to urban and rural labor transfer to cities and towns and the two or three industries, the reduction of agricultural workers, and the development trend of land scale management, will promote the transformation of business entities, the future of cooperatives, family farms and modern agricultural enterprises will become the main force of agricultural management.

Country in the policy and financial support, will further accelerate the formation of new business entities. Policy support, the Chinese Communist Party in the third plenary proposed to encourage the development of professional cooperation, joint stock cooperation and other forms of farmers' cooperatives, guide the operation of the norms, focus on strengthening capacity building. Encourage local governments and private investors to set up a financing Guarantee Corporation to provide credit guarantee services for the new agricultural business entities. Increase the new occupation farmer and new agricultural business entities lead people's education and training". Financial support, in February 2014, the people's Bank of China promulgated the new agricultural management, such as family farms and other financial services guidance, requires financial institutions to increase the credit support for new agricultural business entities, such as family farms, and make an inventory of the amount of funds to support family farms and other new agricultural business development.

Agricultural business model reform

The development of smart phones and wireless Internet technology to promote mobile phones become the main platform for rural information. 2014 rural Internet users use the proportion of mobile Internet access to 84.6%, the development of mobile Internet technology to promote the rapid coverage of Internet technology in rural areas, mobile Internet platform as a rapid release of the advantages, but also to the Internet technology and all kinds of Internet access to rural areas can be.

Agricultural industry has a large market space, industrial backwardness, the information asymmetry is more serious, the large scale of the user, the transaction process is longer, the transaction costs are high, the transaction is highly sustainable and so on, so the potential of the Internet is huge. From the domestic and international agricultural development trend, the Internet and agriculture has begun to accelerate the integration of agriculture, the Internet era has arrived, the Internet is the agricultural industry chain comprehensive transformation, from agricultural sales, intermediary services, the transfer of land to agricultural production, sales of agricultural products, with the Internet thinking of agricultural enterprises from all sectors of the agricultural industry chain on the active layout try to use the Internet, explore various business models.

"Internet +" to the reform of agricultural modernization

2015 central rural work conference to accelerate the modernization of agriculture as the theme, pointed out that we should adhere to the reform as the driving force to technology as the lead, to promote the development of agriculture, transfer mode, adjust structure. Further emphasis on increasing the intensity of reform and innovation. Reference to the development of modern agriculture, the scale, industrialization, modernization, industrialization and gradually formed, the future will further extend to the information, in order to build a modern agriculture, accelerate the transformation of agricultural development mode as the core of agricultural information into a bright spot. From the development of domestic and international, the Internet has begun to merge with the depth of agriculture, the Internet is a comprehensive transformation of agriculture in order to improve the efficiency of agricultural industry and agricultural informatization level.

Industrial chain business model change

Agricultural Internet era has come, the Internet is a subtle way to transform the whole process of agricultural industry chain, and promote the optimization of the industrial chain and improve the efficiency of the. Occur on the basis of effective promotion of large-scale operations, the Internet technology is expected to produce the whole process of agricultural products from production to effectively integrate, involving the whole process of agricultural product traceability system, cold chain fresh, brand agriculture, etc.. In the Internet mode, the agricultural industry chain will form a new business model, to provide more space for the integration of agricultural and agricultural products market trillions.

Opportunities for agricultural service platform

With the advance of modern agriculture, the acceleration of land transfer, the increase of the main body of the new intensive management, and the way of agricultural modernization. New agricultural enterprises put forward higher requirements on the agricultural product supply and service. Coupled with China's huge market capacity of agricultural fertilizer, seed, feed, only three kinds of size over one trillion yuan. In recent years, Internet companies are "going to the countryside", to seize the rural electricity market, in the objective to cultivate rural business, stimulate the vitality of rural electricity providers to help agricultural development of the electricity supplier. At present, agricultural electricity providers model is the main mode and the third party business platform of agricultural enterprise self mode etc.

Information platform based on Internet of things

Things are recognized as the world's third wave of world information industry after the computer, Internet and mobile communication network. It is based on perception as the premise to realize the network of people and people, people and things, things and things. And the farm is through the sensing device to obtain crop information, on the basis of all kinds of network transmission, the central system for remote operation, information awareness -network transmission -decision support -remote control is the four basic chain of agricultural things. The essence of agricultural informatization is to transform the agricultural production from the traditional mode of labor to achieve efficient production by means of information, and to construct the Agricultural Internet of things that people and things are fully interconnected. From a broad sense, all agricultural information form of expression are in the category of agricultural things, the Internet of things is the soul of agricultural information. Throughout the country's latest application situation, the Agricultural Internet of things in the four areas of the main effect.

E-commerce platform for agricultural products circulation changes

2015 rural work conference pointed out that the circulation of agricultural products to support innovation, business, logistics, trade, finance and other enterprises to participate in the construction of agricultural e-commerce platform. 2015, the Ministry of agriculture also rural e-commerce as an important means to improve production efficiency, change management mode, the main business of agricultural production and business skills training, organization of agricultural production and business entities and business enterprises docking, to carry out agricultural ecommerce pilot and other aspects of the work.

Conclusions

The arrival of the information economy has brought new infrastructure, new elements, the establishment of the new division of labor, the establishment of a new agricultural product circulation model to provide a possible. Under the catalysis of the Internet, the distribution mode of agricultural products is changing, the new mode of electronic commerce is the main form of the rapid rise, in the main form of circulation, the organization, the impact of upstream and downstream, etc.

Acknowledgment

Funds for this research was provided by the National Science and Technology Plan Projects (2014BAD08B05), Science and Technology Projects of Shandong Province (2013GNC21006), Independent Innovation Projects of Shandong Province (2014ZZCX07104).


Man Qian

Qingyan Wang

Liping Chen

Wenqian Huang
email: huangwq@nercita.org.cn

Shuxiang Fan
email: efanshuxiang8903@163.com

Baohua Zhang
email: fzhangbaohua@sjtu.edu.cn

Penetration depth of near-infrared light in small, thin-skin watermelon

Keywords: Near-infrared spectroscopy, penetration depth, transportation features, diffused transmission spectra, small, thin-skin watermelon

Non-destructive detection of internal quality in watermelon has very important significance for improving watermelon's production efficiency.

Near-infrared (NIR) spectroscopy is one of the most popular non-destructive detection methods. However, it is challenging to collect spectra exactly due to the multiple scattering and absorbing by the skin and internal tissues. In order to obtain the interactions between light and watermelon tissues, the transportation feature of NIR light in small, thin-skin watermelon was studied in the range of 750~900 nm. For this purpose, the diffused transmission spectra were collected with removing the sample slices along the perpendicular bisector of the source-detector line. Based on the spectra in effective wavelength band, the penetration depth curves were fitted by least square method, and the results of different detecting positions (equator and top) were compared. It was shown that, light penetration depth on the equator was 8.3~9.5 mm, 8.7~17.8 mm and 18.9~38.5 mm with source-detector distance of 10 mm, 20 mm and 30 mm, respectively. The penetration depth on the top was less than the equator. And the penetration depth increased with source-detector distance increasing. With deeper penetration depth, more information about internal quality was carried by the diffused transmission spectra. However, the intensity of spectra was weaker. According to these results, a reasonable source-detector distance could be designed for collecting effective information about internal quality. This study is of potential significance for optimizing the handheld probe geometry for large fruit, and offers theoretical bases for non-destructive detection.

Introduction

Watermelon is one of the most popular fruits in summer, and its consumption is large. With the development of consumer's demand for fruit's quality, more attention have been paid to the internal quality, including soluble solid content, taste and nutritional value. And high internal quality can enhance the competition of domestic watermelon. However, due to the excessive watering and unreasonable fertilization, the quality of watermelon has fallen down with increasing planting area in recent years. Therefore, it is important to detect watermelon's internal quality at the postharvest handling and processing stage. However, the traditional detection method which mainly depends on destructive sampling is inefficient. It also cannot be applied widely. And it is urgent to develop a fast and non-destructive detection method to improve watermelon's internal quality. Near-infrared spectroscopy has many advantages, including efficient analysis, fast execution, reproducibility and without sample pre-processing. And it plays a vital role in non-destructive and fast detection for fruits and vegetables. Near-infrared spectroscopy has already been used to detect watermelon's quality, such as firmness [START_REF] Tian Haiqing | Study on Predicting Firmness of Watermelon by Vis/NIR Diffuse Transmittance Technique[END_REF] , soluble solids content [START_REF] Zhang Fan | Content Determination of Sugar and Fiber in Watermelon by Near-Infrared Spectroscopy[END_REF][START_REF] Jie | Using visible and near infrared diffuse transmittance technique to predict soluble solids content of watermelon in an on -line detection system[END_REF][START_REF] Tian | Measurement of soluble solids content in melon by transmittance spectroscopy[END_REF] and maturity [START_REF] Abebe | Total sugar and maturity evaluation of intact watermelon using near infrared spectroscopy[END_REF][START_REF] Li Yongyu | Maturity Qualitative Discrimination of Small Watermalon Fruit[END_REF] . And near-infrared spectroscopy with diffused transmission is more suitable for developing portable detecting system. Therefore, it is significant to acquire the transmission features and penetration depth of NIR light in watermelon's tissue. Many researches on light penetration depth in fruit have been reported by domestic and foreign scholars. The light penetration depth in fruit can be estimated by using the coefficient of absorption and reduced scattering [START_REF] Qin | Monte Carlo simulation for quantification of light transport features in apples[END_REF] .The direct experimental measurement includes using a black knife to hinder light penetrating into the fruit [START_REF] Chen | Light transmittance through a region of an intact fruit[END_REF] , removing the sample slices gradually [START_REF] Lammertyn | Light penetration properties of NIR radiation in fruit with respect to non-destructive quality assessment[END_REF][START_REF] Han Donghai | Information Collection of Mini Watermelon Quality Using Near-infrared Non-destructive Detection[END_REF] and piercing the fruit by optical probe to measure directly [START_REF] Fraser | Light distribution inside mandarin fruit during internal quality assessment by NIR spectroscopy[END_REF] .However, the research subjects are small fruits, such as apples, oranges, mandarins, tomatoes or pears. And researches on lager fruits have been rarely reported, such as watermelons. To solve this problem, in this paper the diffused transmission spectra were collected, which were fitted by partial least square (PLS) method. Then the penetration depth on the equator and top were obtained with different source-detector distance (10 mm, 20 mm and 30 mm). And a suitable source-detector distance could be designed to reach effective transmission depth in watermelon. It provided technical basis for developing portable and non-destructive detection equipment for large fruits.

Materials and methods

Fruit samples

In this work, two small, thin-skin watermelons (Te Xiaofeng) were purchased from a fruit shop in Beijing. The vertical and horizontal diameters of watermelon are about 120mm. And there are few defects on watermelon's surface. And they were placed in the room condition(20℃) for more than 24h to avoid the influence of temperature on the detection results. The detective positions have no defects, and the light intensity can't destruct watermelon's tissue. The samples were labeled to detect the penetration depth for the equator and top, respectively.

The system setup and diffused transmission spectra collection

Fig. 1 illustrates the experimental setup. The system for collecting spectra included a halogen lamp (Illumination Technology, 50 w), portable Near-infrared spectrometer (USB 2000+,Ocean Optics, US, 500~1100 nm), probe of optical fiber (Ocean Optics, US), fruit holder and computer. The spectrometer's resolution is 1.7nm and integral time is 2s. In order to avoid stray light, the fiber probe, watermelon sample and fruit holder were placed in the black light box. Meanwhile, the source fiber probe and detector fiber probe aimed at the labeled detective position, tightly. Then the diffused transmission spectra could be collected. Fig. 2a shows the illustration of spectra collection. The spectra were collected with removing the sample slices along the perpendicular bisector of the source-detector line on the basis that the light transmission path is "banana-shaped" between the source and detector [12] . The half of watermelon was used as the original melon slice for spectra collection because of the light penetration depth less than half a watermelon. The spectra of each thickness slice were collected with different source-detector distance until the thickness is about 1mm. The slice thickness values were 57.9, 45.8, 30.4, 23.3, 13.6, 11.3, 7.5, 5.6, 3.4, 1.2 mm. The spectra were collected for 5 times on the same position for each thickness slice, and the average spectrum of five times was used to analyze transportation features and penetration depth.

Spectral data preprocessing and analysis

Spectral data preprocessing

In this study, Savitzky-Golay was used to smooth the original spectra. The processing window was 7 and calculation time was 3. After Savitzky-Golay preprocessing, the feature information was strengthened and random noise was weakened.

Light penetration depth for single wavelength

For each wavelength (λ), the spectra of thickest slice are the reference spectra (I 1 ) to the spectra (I n , n=1,2,…10) of each thickness slice (δ n , n=1,2,…10,δ 1 >δ 2 >…>δ 10 ), called are compared.

Then a non-linear model of the form g n =1+a• exp(b, δ n ), with the parameter of a, b. And g n (the I 1 /I n ratio) is the fitted value. δ n (the thickness of watermelon slice) is fitted to measured points, using the least squares method. Then δ 1 /0.1 points of the fitted curve are taken, and the step length is 0.1 on the horizontal ordinate. An infinitesimal ε is given. A certain point [δ(x), g(x)] to neighboring point [δ(x+δ1/0.1), g(x+δ1/0.1)] is compared. If [g(x+δ1/0.1)-g(x)] 2 <ε,the value of x is approximately penetration depth of the wavelength (λ).

Light penetration depth in effective wavelength range

Because the NIR light in 750~900 nm is low absorption and high scattered in biological tissues, the light can penetrate several centimeters in the tissues [START_REF] Li Hui | Visible and near-infrared light scattering model of biological[END_REF] . Due to the systematic error and random noise, the wavelength range in 750-900 nm is to analyze penetration depth, and the step length is 20nm. For each wavelength, the penetration depth was fitted by lease square method as the single wavelength.

Results and discussion

Features of NIR spectra

1 1 2 10 n n I g
,n , , I    Fig. 3 shows the diffused transmission spectra with varying thickness on the equator when source-detector distance is 10 mm. Due to the high relative transmission and low reflectance, the spectra of the thinnest slice are at the bottom. The spectra of thicker slices are on the top. When the slice thickness is 7.5 mm, the intensity of spectra fell significantly. It indicates that the NIR light transmit the slice and the penetration depth is about 7.5 mm. When the slice thickness is less than or equal to the penetration depth, light will transmit the slice and thus reflect less. The signal to noise ratio is lower with further source-detector distance and the light transportation features make little difference on the equator and top.

The penetration depth for single wavelength

Fig. 4 shows the fitted penetration depth curve for peak wavelength. When source-detector distance is 10mm, the penetration depth is 8.4mm on the equator. Table .1 shows the penetration depth of peak wavelength with different source-detector distance on the equator and top. As shown in Table .2, the maximum penetration depth is 29.8mm and 21.1mm on the equator and top with 30mm source-detector distance, respectively. And the minimum penetration depth is 8.4mm and 8.3mm on the equator and top with 10mm source-detector distance, respectively. It is noticed that the penetration depth is deeper with further source-detector distance on the equator and top. Meanwhile, the penetration depth on the top is less than the equator.

The penetration depth in effective wavelength range

Fig. 5 shows the penetration depth curves in effective wavelength band. On the equator, the penetration depth is nearly 10mm with source-detector distance of 10mm and the penetration depth curve is less volatile. It is because that the NIR light is mainly scattered due to the low penetration depth. The penetration depth is 8.7~17.8 mm and 18.9~38.5 mm with source-detector distance of 20 mm and 30 mm, respectively. Because the slice absorbs more and optical energy decreases with wavelength increasing, the penetration depth falls down. The transportation features make little difference on the equator and top. And the penetration depth on the top is less than the equator. It is probably due to less soluble solid content and more water in the top than the equator. The slice absorbs more and the penetration depth is less on the top.

Table .1 shows the penetration depth range and wavelength to largest penetration depth with different source-detector distance on the equator and top. The wavelengths to largest penetration depth are all in the range of 750~800 nm, indicating the NIR light in this range being low absorption feature. And the penetration depth increases with source-detector distance increasing on the equator and top, as is according to Monte Carlo model [START_REF] Wang | Monte Carlo modeling of light transport in multilayerd tissues[END_REF] .

Conclusions

In this paper, the diffused transmission spectra in the range of 750~900 nm were collected with removing the sample slices. And the penetration depth curves of equator and top were fitted by partial least square method. Results showed that, the penetration depth increased with source-detector distance increasing, and more information about internal quality could be carried by spectra. However, the intensity of spectra was weaker. The transportation feature made little difference between equator and top, but the penetration depth on the top was less than the equator. The result is helpful to design a reasonable source-detector distance for achieving effective penetration depth. And it can provide reference for developing portable and non-destructive device for large fruit.

Fig. 1 .

 1 Fig. 1. Illustration of spectra collection system

2 , , 3 ,

 23 Fig.2ashows the illustration of spectra collection. The spectra were collected with removing the sample slices along the perpendicular bisector of the source-detector line on the basis that the light transmission path is "banana-shaped" between the source and detector[12] . Fig 2b shows the position of source fiber probe and detection fiber probe, including 1,2,3 source points and 1 , ,2 , ,3 , detection points. The distance between source and detector is 10mm, 20mm, 30mm, respectively.

Fig. 2 .

 2 Illustration of collecting spectra

Fig. 3 .

 3 Fig. 3. The diffused transmission spectra with source-detector distance of 10mm on the equator

Fig. 4 .

 4 Fig. 4. The fitted curve of penetration depth for single wavelength

Fig. 5 .

 5 Fig. 5. The penetration depth curves in effective wavelength range

Table 2 .

 2 Penetration depth for peak wavelength

	Position	d(mm)	Peak wavelength	Penetration
			(nm)	depth(mm)
		10	807.95	8.4
	Equator	20	804.33	14.5
		30	793.46	29.8
		10	810.24	8.3
	Top	20	804.00	13.2
		30	806.63	21.1

Table 2 .

 2 Penetration depth in effective wavelength range

	Position	d(mm)	Wavelength to largest penetration	Penetration depth
			depth (nm)	range (mm)
		10	755.26	8.3-9.5
	Equator	20	754.14	8.7-17.8
		30	770.21	18.9-38.5
		10	754.14	8.5-9.3
	Top	20	757.50	7.2-15.6
		30	757.50	8.4-31.2

Acknowledgment

The authors sincerely acknowledge the support Beijing Municipal Natural Science Foundation (No.6144024), and Beijing Academy of Agriculture and Forestry Sciences Foundation for Young Scholars (QNJJ201423).


Dan Wang
email: wangdan01@caas.cn

Xiaorong Yang
email: byangxiaorong@caas.cn

Jian Ma
email: cmajian@caas.cn

Liping Zhang
email: dzhangliping@caas.cn

, Xiaorong Yang

Retrieval Methods of Natural Language Based on Automatic Indexing

Keywords:

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

When the computer retrieval system has just entered the practical stage, people soon find its defects in retrieval time lag, retrieval feedback results, and to develop more convenient and efficient online retrieval system in the terminal. However, in the online era, the adverse effects of a full-time retrieval personnel and user questions needs have become a new reality questions. To this end, people have developed a variety of user-friendly man-machine interface. Today, access to the network retrieval, the user of retrieval system has undergone fundamental changes, the end-users who have different ages, different occupations, different knowledge backgrounds, different experiences have become increasingly demanding for retrieval system of convenience, immediacy and transparency. Thus, retrieval system (user interface) with the ability to understand natural language are increasingly welcomed by the majority of users, become an important part of the network retrieval system. Natural language also known as "everyday language", it is a tool for expression and exchange of ideas in everyday life for the long-term social practice, it is very wide application in information retrieval. From the user's perspective, natural language search is users use the words, phrases or natural statement of daily life for questions. From the technical side, natural language retrieval is the natural language processing technology applied in information retrieval system of information organization and indexing, and output 【1】 . In information retrieval, the so-called natural language is relative to the case of controlled language, natural language is essentially a raw and standardized treatment of uncontrolled language. The whole process from the point of view of information retrieval, natural language search is including two aspects of natural language indexing and natural language query question. Natural language search is a direct order from the source document as the index identifies the content, users can directly use the natural language questions and complete a form to retrieve information retrieval.

Status of Natural Language Retrieval

Natural language retrieval was born in computer search, arising from the date it would have equal shares and information retrieval language. It is because natural retrieving language has its own advantages, it has long attracted people's attention, so that domestic and foreign scholars and experts to study it. Study abroad can be traced back in the 1960s, research focused on the automatic indexing achieve human indexing effect, the main representative of the study from the initial American scholar Salton and Bely, and later the American scholar Sparck, John, Tait, Fagan, Croft, Turtle, Lewis and so on; To the 1990s, TRC (Text Retrieval Conference Text Retrieval Conference) natural language search system began to participate in trials and competitions 【2】 . From TREC-1 meetings to TREC-6 meeting, the study of natural language search continues to move forward, its research focus on from the original statistical methods to the study of query expansion mode and flow index merge algorithm. The late 1990s, many foreign well-known databases such as Dialog, BIOSIS, ProQuest online, also started to provide natural language search interfaces in their own retrieval system and try natural language search. Many network-oriented information resource retrieval of test systems and the search engine uses a certain amount of natural language search technology, to a certain extent, to achieve a natural language search function, these test systems and search engines are: START、 IRENA 、 FERRET 、 Ask Jeeves ( http://www.ask.com )、Geoquery ( http://www.cs.utexas.edu/users/ml/geo.html )、ixquick (http://www.ixquick.com)、Northern Light(http://www.northernlight.com)、 Ask Northern Light a question、Electric library(http://www.elibrary.com)and so on. Before the 1990s, in the domestic field of information retrieval research on natural language search in natural language indexing, other studies have concentrated on the theoretical discussion on the text indexing by natural language. After the middle of 1990, there have been some studies on the user interface. Professor Zhang Qiyu was the earlier focus on natural language search scholars, he made a more in-depth study on a variety of factors natural language indexing information retrieval efficiency. He proposed text type, the search range, the search terms of the degree of specificity, the wording of the text is not standardized, different indexing methods and the degree of control of natural language search system would have an impact on 【3】 . National Taiwan University Department of Library Chen Guanghua used LOB Corpus as the training corpus, used SUSANNE Corpus as test Corpus, studied the natural language retrieval on the syntactic level 【4】 . In recent years, there are some practical web search engine to provide natural language search in China, there are TRS retrieval systems, Eureka search engine and Naxun Chinese news search engine. It is worth mentioning that the "Baidu knows" is the most influential of the Q & A platform -natural language search system. As of September 15, 2012, "baidu knows" " the use of natural language retrieval methods has solved the problem of 200 million [START_REF] Jia | Research on Assessment of Answer Quality in Social Q&A Platform[END_REF] .

The key issues of natural language search

Natural language search includes two aspects, namely natural language indexing and users retrieve by using a form of natural language questions. These two aspects can work independently, in technology implementation respectively, at the same time, they have close connection each other. The former is to standardize the indexing of natural language retrieval. The latter is to provide a natural language interface for users to ask questions, make information retrieval system to retrieve user needs to understand natural language in the form of expression, and processes the user's natural language questions. To solve these two areas, we depend on the following key technology research and development [START_REF] Qian | The Pivotal Issues and Implementation of Natural Language Information Retrieval[END_REF] .

Subject Indexing.

One of the key issues of natural language search is how to extract most accurately fuller expression of documentation related to the topic words from the document. As well as the relationship between the words in a document expressing the theme concept, and this relationship is stored in the index, to support subsequent retrieval.

Question treatment.

Another key issue of natural language search is user's natural language questions by expressed understanding of computers. Ideal retrieval system should be able to "understand" the real search request which users use natural language expression. Not only retrieval system understands the significance of the user clear statement, but also understands the hidden meaning in natural language questions to be expressed. Thus, end users do not need to bother to go more express retrieval needs, learning tedious search command format.

Questions and index matching.

Ask and index of effective matching is another difficulty in natural language retrieval. Specific matching algorithm depends on the structure of the index and quiz process technology. Meanwhile, adopted retrieval model will largely affect the matching algorithm and effect.

Control Concept.

In essence, natural language search is a concept search, it requires a certain conceptual system or knowledge database to support. Knowledge of knowledge database can help solve the problem of natural language questions differentially expressed, that is a solution to the information source text and user questions related to the use of different words to express the concept of problem. The synonyms and near synonyms in the knowledge base can achieve control of the concept of words, to eliminate the difference of word brings the retrieval accuracy.

Natural Language Indexing

Factors affecting the quality of indexing.

In the information retrieval system, indexing methods and results have a greater impact on the retrieval results. Currently there is no indexing full-text indexing and word extraction indexing form keyword index of automatic indexing method. Quality of indexing directly affects the natural language retrieval results, influencing factors quality of indexing:

Indexing depth

Indexing depth is used for indexing a document identification (keyword) number. It reflects the indexing on the degree of comprehensive and specifically to the theme of the document analysis. In general, the depth of indexing (indexing terms more) is the greater, the recall is the higher.

The relationship between words of indexing words

The theme of the document is composed of multiple indexing words together common expression. There are certain grammar and restrictions relations between indexing words. For example, the position and the order of indexing words and relationship of index terms and synonyms and so on. In the process of automatic indexing, the more accurate analysis of the relationship between the word of the word, the more in the index expression, the complete retrieval result is better.

Indexing size

During indexing, text block which indexing object points can be called indexing unit. Indexing unit refers to how large blocks of text to generate a set of index terms, it reflects the index object size. On the premise of indexical meaning, the smaller indexing particle size, the more sophisticated, the better retrieval refers specifically. Several factors described above is directly related to this article.

Automatic indexing method.

Automatic indexing is to use the computer to give corresponding to deal with literature searching, the process of indexing is divided into classification indexing and subject indexing. Subject indexing is divided into title lexical, lexical unit, syria lexical and keyword method. The first three indexing methods belong assignment indexing method index, the latter belongs to the extraction indexing words. Assignment indexing requires a thesaurus for support. This article relates to the automatic indexing is assigned indexing words

【7】

. This article use the keywords table is by the agricultural information institute, Chinese academy of agricultural sciences "computer automatic indexing research" compiled by the "computer automatic indexing multifunctional agriculture word", there are " use, generation, genera, divide and reference" and other relations between each item, can cut out from the document keywords conversion, automatic indexing given keywords, synonym, synonyms, related words, and the quest for word to complete the indexing concept of control. There are three methods in the general automatic indexing. The first one is segmentation method based on string matching, the second one is the segmentation method based on understanding, the third one is segmentation method based on statistical word 【 8 】 . Segmentation method based on string matching is Chinese character string and entry words in dictionary match according to a certain strategy, given an indexing word after a successful match. According to different scanning direction, it can be divided into forward match and reverse match. According to the different length matching of different priority, it can be divided into the biggest (longest) and the minimum (minimum) match.

4.2.1Forward longest matching method(MM methods)

The strings obtained by coarse segmentation have been verbatim scanned from left to right and match with Thesaurus, and the keywords of thesauri maximum matching as the primary keywords. For example, in thesaurus in the "cadres tenure" in Chinese, and also included "cadres"、"office"、"age". Longest matching method is that "A short length is not taken" the word extraction rules, only extracting "cadres tenure" is used.

Reverse longest matching method(RMM methods)

Principle of RMM with MM method is the same. Difference is that the word of the scanning direction, it is taken from right-to-left matching substring. Statistics show that simply using the forward maximum matching error rate is 1/169, simple to use reverse maximum matching error rate is 1/245. Obviously, RMM method in the segmentation accuracy than MM method has been greatly improved.

Minimum Segmentation

Both forward maximum matching and reverse maximum matching, guaranteed indexing words maximum benefit of indexing specificity, is advantageous to the indexing specificity. But the biggest index terms are possible split in order to extract the smaller index terms. This is likely to increase the indexing words, that is to improve the indexing depth. At the time of retrieval, which is beneficial to avoid leak phenomenon. For example, in thesauri "cadres working age" term is maximum matching and indexing, if we the further use of minimum-cut method, there are likely to increase "cadres", "working", "age" indexing terms, indexing terms has increased, can improve recall.

Natural language search implementation

Natural language search is including natural language indexing and natural language query question two aspects. Automatic indexing of natural language are discussed earlier, the remaining problem is the problem of natural language questions and queries. Automatic indexing of natural language are discussed earlier, next we discuss natural language questions and queries and so on.

Natural language query processing.

One of the characteristics of natural language retrieval is to allow users to use natural language retrieval requirements directly to the system. Due to the use of natural language, in the form of natural sentences express questions and system index in the index entry form is different, the expression of document both cannot match directly, So we requires a necessary processing of natural language questions. Discussion of the relevant issues:

Indexing item level

When you retrieve using natural language questions, retrieval system requirements index entries in the language level is completely consistent with the natural language questions. In this paper the method to realize natural language retrieval is limited to the title.

The control of indexing words

Natural language retrieval has the characteristics of concept retrieval, semantic retrieval. Therefore, in order to achieve better search results, we want to deal with natural language questions in concept. Namely, the use of a number of related linguistic dictionaries, such as thesaurus dictionary or conceptual relationships dictionary or related knowledge, we need control natural language words in document title, at the same time we also need control the language (words) on the users of natural language questions. The key words in everyday-language are converted into keywords, and give the corresponding synonyms, hypernym, synonyms, etc. In this paper, the natural language search implementation used a "Computer automatic indexing vocabulary multifunctional agriculture".

Natural language retrieval match.

In information retrieval systems, indexing process is the back-end processing, it participles and matches for the source document, etc. It has established the index data for retrieval. Natural language question processing is the front-end work of system. It also participles and matches for user's natural language question, etc. It provides the interaction between user and the system interface. In the process of natural language retrieval, indexing words between index data and retrieval requirements matched under certain matching control mechanism. It completed to match both generated indexing word. There are three common retrieval models that are Boolean model retrieval, vector space model retrieval and probabilistic retrieval model retrieval.

Vector space model has a simple structure, formal, and easy to implement features. The vector space model retrieval was used in this article. It would document retrieval item (such as titles) and user natural language questions were compared. That is, both the indexing terms would be compared, and use weight to calculate the similarity, and to judge search results by similarity.

The concept control of natural language.

In dealing with natural language question retrieval, Pattern matching calculation is commonly used, namely by keywords (index terms) in comparison to complete. In the process, if it is mechanically simple pattern matching processing, instead of using the concept of the corresponding control, pattern matching will have the following questions. Choice of words there is no strict limit of natural language questions, words more vocabulary more cluttered, it will affect the search results. In order to solve these problems, we must further process natural language question in the matching process, namely, we must control at the conceptual level. Natural language query express retrieval concepts through natural language. The concept of a keyword in natural language is all kinds of relations with other key words. For example synonyms relations, hypernym relations, etc. For example, "microbial fertilizer" concept, based on the relationship between the upper and lower classes can be subdivided into "antibiotic fertilizer", "Rhizobium fertilizer" "nitrogen-fixing bacteria fertilizer," and so on. A simple literal match will cause missed. For example the "computer" and "electron brain" is different expression of the same thing, "potato" and "toodou" is also synonymous. If the user's natural language is "potatoes" (or computer), the word "toodou" (or electron brain) is a term describing a document will be missed. This approach can apply these same concepts are words matching retrieval, thus expanding the retrieval surface, thereby increasing the recall.

Natural language retrieval method.

Following implementation of natural language search will be described, in addition, natural language search to achieve this article is limited to the title of the document (title) levels.

Natural language search process.

Using natural language questions directly match and retrieval with the body or abstracts of the document, and in any case no one article is hit. Using natural language questions directly match and retrieval with the title of the document. Perhaps occasionally one article is hit. Such as natural language search method is certainly not desirable. Therefore, we need automatic indexing process for the natural language questions and databases' document. Natural language retrieval process diagram is as follows: Figure 1 Natural language retrieval process diagram First of all, the automatic indexing does automatic word segmentation for the title of the document and matches the words of thesauri. We will do meaning conversion process to index terms matched. We give index terms. While, we give the word hypernym, hyponym, synonym, synonyms or snare words as index terms. Then we do indexing process for indexing terms. This process is the systematic background does real-time processing to the database and the new information documents. To ensure that the title of the document should be indexing and index update for every new document in a database. In natural language retrieval, the system at the front desk also use the same automatic indexing system and indexing method to natural language question statement (or phrase) for indexing, and indexing words and the information source of indexing words "or" operation matching, matching literature that is hit literature, hit literature form a collection of hit documents, known as B collection.

Hit literature output sorting.

Natural language question

Index terms

Database

Hit the literature collection

Automatic indexing system

Computer indexing multifunctional agriculture vocabulary Indexing words Index terms Match Sorted output Similarity Hit documents by the above methods are a number (n) articles in most cases. For example, indexing terms of natural language question in the statement are A, B, C three words, through A, B, C three words "or" operation to retrieve, any index terms of literature title containing A or B or C word, containing A and B or A and C or B and C words, or containing A and B and C words are retrieved. Faced with the hits literature (B collection), which was first presented to the user, but it has the sort of problem. Sort is based on the similarity of the title of hit document and the user's natural language question statement. Similarity calculation is as follows: Set the A string is indexing terms which natural language query statement provided, for a particular request statement, index terms of A string are fixed. In natural language retrieval, Set hit document is B collection, the title of each article in B collection is automatic indexed, and indexing words of every document form a C string, and indexing words of every document form a C string, so there are a number of C string in B collection, we compared A string with the C string, both indexing words overlap degree, we called similarity. The maximum similarity is 1, indexing terms of A string and indexing terms of C strings are one hundred percent the same. For each C string of the B collection, indexing words of C string and indexing words of A string one by one compares, calculate the ratio coincides both the index word (always less than 1). Thus, a characteristic natural language search results form a plurality of different sizes overlap ratio, Greater overlap percent, the higher the similarity. The coincidence percentage of high and low will be as the basis of the output sequence of the hits literature.

Test

Natural language retrieval was born in computer search, arising from the date it would have equal shares and information retrieval language. It is favored by the majority of users. Natural language search technology is widely used in utility database, news databases, etc. For example, in the field of agriculture practical technology database of crop management and cultivation techniques, plant protection technology, vegetable gardening management and technology and other aspects are more suitable for users to use natural language questions to ask questions for retrieval. "Baidu knows" is a very typical natural language question sentence retrieval practical database. The author did a test by natural language retrieval methods in this paper. Test data is extracted from the CNKI database. Data mainly includes crop(wheat, corn, soybeans, cotton, potato, sesame seeds ) cultivation techniques, pest control technology, gardening vegetable ( cabbage, celery, tomato, carrot, rapeseed ) cultivation techniques, livestock and poultry breeding, marine and freshwater aquaculture, and agro-processing, total capacity of data are more than 5,000. Automatic indexing thesaurus is Chinese Academy of Agricultural Sciences Institute of Agricultural Information compiled by the "Computer automatic indexing vocabulary multifunctional agriculture", a total of more than 40,000 keywords. There is a relation of the subject words, such as "use, generation, genera, division and reference", in addition to the category code and the corresponding net word. Using this method has been tested on the above data, the test results are satisfactory, which is a higher precision. For example, the search statement as "potato cultivation technology", from the test sample data (there are 420 potato literature)and find relevant literature. According to the provided similarity method, followed by the top ranked "potato cultivation technology", "black potato cultivation technology", "precocious potato planting technology", "Heilongjiang province potato mechanized technology ", "potato cultivation comprehensive disease prevention and control measures." and so on. Because the automatic indexing words above topics and natural language search statement are "potato, cultivation techniques, planting techniques, precocious, detoxification, Heilongjiang Province, mechanization, disease, comprehensive prevention and control measures" and "potato, cultivation technology, planting, technology. " According to the degree of overlap between the two indexing terms will have above order. Another example: Search statement was "practical agricultural technology database" only was retrieved two documents in CNKI database. That is, "the WEB retrieval of agricultural practical technology database", "the regional agricultural practical technology database under the network environment". If we use the natural language retrieval method provided by this paper, we can find out the 50 documents. Because it is not a complete word with the search statement to find, but with its indexing word "agriculture, practical technology, database," a "or" operation to retrieve. Of course, so find out more literature, this is why this method will not result in a leak. However, sometimes, check out the document number is too much, in order to save time for the user to browse the documents, the maximum number of documents and the maximum number of views in the literature will be set up. Literature amount exceeds this value no longer that shows the document content. The documents are sorted according to the similarity. In order to meet the same degree of similarity in the literature, the order is also random. In addition, using this method to retrieve must use the same indexing system and thesaurus database indexing and index, in order to ensure the accuracy of the document similarity. In the requirements of retrieval statement, both keywords (keywords), a phrase, or spontaneous statements is the same, the method is applicable.

Conclusion

This article provides a natural language search method based on automatic indexing is a method of natural language retrieval application method easier to achieve. This method has some advantages: (1)Simple user operation, the search condition (statement) requiring a simple and different level of users can operate; (2)System implementation easier. Systems involved in the automatic indexing algorithm module, indexing data module and so on, most of them have more sophisticated software, it is easier to integrate them together into a useful natural language search system.(3) Made some technical standardization process in natural language processing, such as between words of "use, on behalf of, divided, the Senate" and other relations, given the appropriate indexing terms, to improve the documentation of precision and recall. (4)The introduction of the concept of literature similarity. The high degree of similarity literature in the front, the user feels natural language search improved precision. In summary, this method is a simple, practical and ideal natural language search methods.

Figure 2

 2 Figure 2 Document detection number comparison

Acknowledgment

Funds for this research was provided by Technology Innovation Project of Chinese Academy of Agricultural Science.


Fangmingzhang
email: afangmingzhang@126.com

Changhuai Lv

Caiyu Zhang

Path Planning Methods for Auto-guided Rice-transplanters

Keywords: guidance system, transplanter, path planning

Paddy field operation asks for robotization due to labor shortage. In this paper, a set of path planning methods were developed and tested on a guidance for transplanters. Path planning of fieldbody and headland were generated and experimented for 3 years. The path outside field consist of farm lanes connecting garage to paddy field, and a ARC-NODE structure method was proposed. Method of optimal coverage path planning should be researched in near future.

Introduction

There is an increasing demand for autonomous and robotic systems in agricultural domain, such as ridging, seeding, transplanting, and tilling. Due to constraint of field shape and machine size, some research has carried out in coverage path planning (CPP) for agriculture [START_REF] Galceran | A survey on coverage path planning for robotics[END_REF], which looks for paths from a starting point to a target point with maximum cover, minimum repetition and omissions as little as possible, while headland turning is a fact that cannot be ignored. The basic task of a CPP method is producing paths for a single machine. For example, Kise [START_REF] Kise | Field Mobile Robot navigated by RTK-GPS and FOG (Part 3): enhancement of turning accuracy by creating path applied with motion constrains[END_REF] set minimum turning radius and maximum rotation rate as the goal, and used a third-order spline function to create two kinds of path of end turning, namely the forward turning and back turning. Oksanen [START_REF] Oksanen | Path planning algorithm for field traffic[END_REF] divided the path planning algorithm into 2 layer: the upper one divided the whole fields into small plots, while the lower one produce path for every plot. Hou [START_REF] Jinagli | GIS-based path planning method for automated tractor[END_REF] proposed two path planning methods of cultivation. Huang [START_REF] Huang Xiaomao | Turning method and algorithm of agriculture vehicles[END_REF] proposed turn strategies of parallel line paths of agricultural machinery with Ω shape and П shape, and a path planning method of convex plots. Han [START_REF] Han | Path-tracking simulation and field tests for an auto-guidance tillage for a paddy field[END_REF] made a predefined path including C-shape headland turning for his auto-guided tractor. A number of literatures discussed optimal algorithms. Noguchi [START_REF] Noguchi | Path planning of an agricultural mobile robot by neural network and genetic algorithm[END_REF] applied neural network algorithm to learn the movement of the tractor, and used genetic algorithm to find a optimal path. Jin [START_REF] Tang | Optimal Coverage Path Planning for Arable Farming on 2D Surfaces [J][END_REF] employed a genetic model to generate a optimal path. For a 3D terrain application [START_REF] Tang | Optimal Coverage Path Planning on 3D Terrain [C[END_REF], Jin modeled the terrain, and constructed a cost function based on a "seed curve" to find the optimal path. Hameed [START_REF] Hameed | Driving angle and track sequence optimization for operational path planning using genetic algorithm[END_REF] also divided this problem into two stages. The first stage expressed geography relations, and the second one made optimal path. Mariano [START_REF] Mariano | Reducing fuel consumption in weed and pest control using robotic tractors[END_REF] developed an optimal path for reducing fuel consumption in weed and pest control. Linker [START_REF] Linker | Path-planning algorithm for vehicles operating in orchards[END_REF] used the A* algorithm to determine the optimal path for vehicles operation in orchards. Jensen [START_REF] Jensen | Coverage planning for capacitated field operations, part II: Optimisation[END_REF] developed an algorithmic approach for the optimisation of capacitated field operations using the case of liquid fertilising, which optimised in a post-process stage that the nonproductive travelled distance in headland turnings is further minimised. Liu [START_REF] Xiangfeng | Optimal path planning method for GPS guided tractors[END_REF] applied a bidirectional link table to express a complex polygon, and then it was divided into simple polygons, and made optimal path to cover subarea. Bochtis [START_REF] Bochtis | Route planning for orchard operations[END_REF] generated routing plans for intra-and inter-row orchard operations, based on the adaptation of an optimal area coverage method developed for arable farming operations . However, an optimal solution cannot be guaranteed commonly due to several constraints, including soil compaction, contour of field, and agronomic constraints. To cooperate working with other agricultural machines, or in form of multi-robot, CPP methods were also proposed. Volos [START_REF] Volos Ch | A chaotic path planning generator for autonomous mobile robots[END_REF] proposed a chaotic path generation methods to cover whole area, whose advantage is that can quickly adapt to the changes in the environment. Bochtis [START_REF] Bochtis | Path planning for in-field navigation-aiding of service units[END_REF] divided the field into grids and then used optimal method to plan paths. Jensen [START_REF] Jensen | In-field and inter-field path planning agricultural transport units[END_REF] proposed a path planning method for transport units in agricultural operations involving in-field and inter-field transports with an optimization criterions of time or traveled distance. in the case of irregular field shapes and the presence of obstacles within the field area, Zhou [START_REF] Zhou | Agricultural operations planning fields with multiple obstacle areas[END_REF] develop a planning method with multiple obstacles. It could be seen that CPP method for machines of paddy fields is still scarce. The objective of this paper is developing in-field and inter-field path planning methods for autonomous rice transplanters. .

Material and Methods

platform

Two transplanters, one is a PZ60 (ISKI, Japan, figure1.a), and another is a NSD8 (KUBATA, figure1.b), were used for the verified the path planning methods. The guidance system consisted a RTK GPS receiver (Beidou, Qiwei), an attitude sensor (Xi'an) and an electric steering wheel The RTK GPS receiver was mounted above the steering wheel with height to ground of 2.5 meters. The attitude sensor was installed in a box with shock absorption device. As more than 90% paddy fields are rectangle shape, it is a fundamental function to plan path for a rectangular field. In our previous research, we proposed a coordinate transformation method [20], which established a local coordinate system as shown in figure 2. A transplanter generally plants rice seedling row by row perfect straight, and stop planting when in headland area, which leads to two kinds of sub-fields, one is the fieldbody, another is the headland which is narrow and surround the fieldbody. Path planning in the field was then divided into these two sub-fields. Furthermore, farm lanes connecting a garage to paddy field consists of several straight roads, these paths could also be planned and the transplanter could then autonomously move between these two point.

Path planning in fieldbody

If the operating width is w L , and distance from the GPS point to the seedling point is G L , then the distance between two neighbor rows is:

w dl L L  (1)
As the minimum turning radius of the transplanter is only 0.8 meters, the guidance system could rotates the steeling wheel with the maximum rotate angle that the transplanter could be in the correct position of the next row, named a pi-turn. When the transplanter is ready to plant in a new row, coordinate of the starting point should be:

         G e sny dl w e snx L L P L n L L P 2 / (2)
Where, ) are the coordinates of the starting point and ending point in the 1st row of SR working respectively. Other points could be produced like similar method as equation 6 and 7.

P s0

Path plan for triangular shape field

Some fields neighbor to field lanes might be triangular shape or diamond shape due to topography restraint. If the machine moves parallel to upper base line of the field, such as OA or BC shown in figure 4 , it would cover field as much as possible. Two slopes of the bevel edges of triangular are:

C C x y  1 tan (8) A B A B X x y y    2 tan (9)
If the working path parallel to line OC is

          G w snx sny dl w e snx L L P P L n L L P 1 1 cos 2 / tan 2 /   (10)
With the similar way, we could get the working path parallel to line AB, which is:

2 2 cos 2 / tan   w OA L L x y    
. For any working path, coordinate of the ending point is:

         

Path plan for farm lane

Generally, path between garage of transplanter and paddy field consists of straight line lanes, which might be two-way roads or one-way farm lanes, whose feature is that they are parallel or vertical to each other as shown in figure 5. If latitude and longitude of two points in every farm lane were measured and an original point was set, the road model of any farm lane could be expressed as

b x y      ) 90 tan( (12)
Where,Ø is angle between the road and north direction b is intercept of this line. ARC-NODE structure [START_REF] Xiaoyu | Study on path planning of logistic system base on multiple AGV systems[END_REF], consisted of 3 tables, which were node Where Count is the number that connected with this point. Structure of road section was defined as Line_ID S_Point E_Point Line_Type Heading angle/curvature radius Where S_Point and E_Point are starting point and ending point of this Line_ID. Line_Type are divided into 3 categories, which are two-way straight road, one-way straight lane, and arc lane. Heading angle is corresponding to straight line type, while curvature radius is for arc lane. Depth-first search method was used after a starting point and an ending point were set, which traverses from a starting point to a new point that connects with the starting one, and from the new point it would be another starting point if there was any line be not traversed yet. Two shortest paths would be constructed in the map for decision.

Results and discussion

Path planning for rectangular field, including the one in fieldbody and headland, were successfully tested on in summer of 2013 with the PZ60 transplanter at Yinzhou, Zhejiang Province. The operation width is 1.8 meters, and the width of headland is 3.6 meters. Two kinds of path planning were experimented, which called three-points guidance and four-points guidance. In the experiment of three-points guidance, a driver steered the transplanter and planted the first row, which formed a reference line for the guidance system. He pressed a button on the guidance controller to get the first point 'A' when starting to plant. He pressed the button again to get the second point 'B' when arrived at end of this row. The 3 rd point 'C' was got after a headland turn to the 2 nd row. After that, the path planning module generated paths for fieldbody. Figure 6 is one set of testing track diagram, that the autonomous transplanter moved on north or south direction in diagram (a), and on east or west direction in diagram (b). Among them, the red is the planned path, blue is a trace of RTK -GPS. It shows the blue points do not overlap with the red line in straight moving stage, which caused by position of the RTK-GPS, who was not fixed in the middle of the transplanter precisely, and and calculation error when transformed from latitude-longitude angles to Cartesian Coordinates.

Conclusions

A path planning method for rice transplanter has been developed and validated partly. Paths for fieldbody and headland in rectangular field were generated and had been used in practice for recent three years. Offset of row following was less than 5 cm, and row-to-tow error was less than 5 cm too. From the experiments, it shows the guidance system could replace human driver for steering controlling. The path for triangular shape field and farm lanes were proposed, while experiments will be done in autumn of 2015. However, optimal method for path planning, and method for collision avoidance in condition of cooperated multi-robots should be research in future that human can control transplanters, tractors, and combines at off-vehicle place.

Figure 1 .

 1 Figure 1. Two test platforms, (a) theISKI's PZ60, (b) theKUBATA's NSD8

LFigure 2 . 2 . 3

 223 Figure 2. Path plan of the standard rectangle field 2.3 Path planning in headland After finishing planting the last row in the fieldbody, the machine should start a round planting , which might be clockwise or anticlockwise. As shown in figure (3), coordinate of the starting point and ending points of the new first row should be:      

.

  For any working path, coordinate of the starting point is:

2 Figure 4 . 1  and 2 

 2412 Figure 4. Path plan of triangular shape field, where

Figure 5 .

 5 Figure 5. Map of farm lanes

Figure 6 .

 6 Figure 6. Planned path and measured track in north-south and west-east directionIn the experiment of four-points guidance, the driver got latitude and longitude of 4 corners of the field before planting operation. Point 'A', 'B', 'C', and 'D' were got with sequence of position at southwest corner, northwest corner, northeast corner, and southeast corner. When the transplanter moved into any corner of this field, the path planning module generated paths in fieldbody and headland. The guidance system guided the machine in fieldbody firstly, and turned to headland after finishing operation in fieldbody that cover whole area automatically. In summer of 2013 and 2014 those experiments were carried out successfully too. Path planning for farm lane have been testing on the NSD8 machine in summer of 2015 at Cixi, Zhejiang Province. A series of experiments will be done in recent days.

  table, topology table, and road section table, is a normal method to express the spacial relationship of different lanes, in other words that these 3 tables construct a navigation map. Structure of node table was defined as

	Point_ID	x		y	Point_Type	Number_Info
	Where Point_Type were divided into 4 categories, which are Cross (intersection point), Angle
	(quarter turn crossing), Number (In/Exit station), and End (terminal of a lane). Number_Info is a
	serial number if the point belongs to Number type.
	Structure of road section was defined as
		Point_ID	Count	Point1 Point2 Point3 Point4

Acknowledgments

The author wishes to express his sincere thanks for the financial support from Developing Foundation of NingBo (2014C10016, 2015C10012).