Yujian Yang

Lili Wang

Qingyu Chen

Jingling Li

Agent-based Simulation of Rural Areas and Agriculture Information of 11 Country Units in Shandong Province

Keywords:

This paper constructed the agent-based modeling framework and discussed the mechanism and implementation of agent-based rural areas and agriculture information by open-source program on country scale. In the paper, 13 indices were proposed to measure the rural areas and agriculture information level in the overlay 11 country regions located in Yellow River Delta and the Blue Economic Zone of Peninsula. The energy node agents represented for informatization involved in agent context were also constructed, network and grid of rural areas and agriculture information. In the study, 11 informatization node agents were given as the energy for the comprehensive evaluation of rural areas and agriculture information, which indicated the strength changes of rural areas and agriculture information. Correspondingly, the node process simulation of rural areas and agriculture information was explored from dual strategy mechanism driving. Then the agent energy transmission mode was put forward for 11 informatization node agent, after that three grades change status of energy transmission was displayed in the study, which responded to the gradient changes of rural areas and agriculture information. Moreover, the spatial process of 11 informatization nodes was obviously described by the agent simulation with the Repast-S IDE, and the unsealed link among node agents was also analyzed in the paper.

Introduction

The emergence of new technologies has evolved in rural areas and agriculture information domain. Agent-based modeling and simulation (ABMS), as a part of distributed artificial intelligence, has developed rapidly since it arose from 1970s, and it was a popular direction of artificial intelligence now. Agent-based modeling and simulation currently provided methods and tools for solving complicated problems decision, and for setting up distributed, intelligent, integrated, and man-machine harmony decision making supporting system. In conclusion, ABMS has given us a new way to look at distributed systems and provided a path to more robust intelligent applications [START_REF] Bordini | Programming multi-agent systems in agents peak using Jason[END_REF][START_REF] Bordini | Verifying Multi-Agent Programs by Model Checking[END_REF][START_REF] Yeping | Application of Agent in Agricultural & Forestry Economy Decision Support System[END_REF] .

In recent years, ABMS theory and technology have rapidly developed. Olfati-Saber presented a theoretical framework for design and analysis of distributed flocking algorithms and provided a theoretical framework for analysis of consensus algorithms for gent network system Badjonski and Bentham had developed agent expert system for genetic breeding and management of crop production [START_REF] Olfati-Saber | Flocking for multi-agent dynamic systems: algorithms and theory[END_REF]5] . Agentbased modeling is intended to explore the relationship between observed spatial patterns and the process creating them(parker etal.2003) [START_REF] Parker | Multi-agent system for the simulation of land-use and land-cover change: a review[END_REF][START_REF] Johnston | Agent Analysis Agent-Based Modeling in ARCGIS[END_REF] .

2

Material and Methodology Five-Year Plan of China. So agent simulation based on rural areas and agriculture information was obviously significance from the case study.

The system establishment of indicators was the premise of energy transmission mode of rural areas and agriculture information nodes, so we constructed the indicator system referred to the new countryside planning of socialism construction from the following principles of Development and Reform Commission of Shandong Province "developed production, affluent life, civilized rural atmosphere, clean and tidy village and democratic administration." Combined with the well-off indices from Wu Dianting (2006), the data were effectively collected and the selected 13 indices were applied in the study [START_REF] Parker | Multi-agent system for the simulation of land-use and land-cover change: a review[END_REF] . Six indices (Enger's coefficient, per house area of household, tap water countryside, household car, hospital numbers, urbanization) responded to the material life. Three indices reflected spiritual life (telephone communication countryside, cable television countryside, patents per year). Two indices were about income and distribution aspect, including per capita net income and per capita GDP. Population quality was reflected by 2 indices (students in middle school and per capita expenditure of education, science-technology and culture). As mentioned, the system of measurement indices was used to define the energy of rural areas and agriculture information nodes and explore the agent energy simulation process of rural areas and agriculture information level. Key steps were carried out to deal with the correlation data, including data acquisition, elimination dimension, determination of index weight, model establishment, comprehensive index computerization and comparison analysis, the results showed the weight values of 11 Informatization Nodes was 13.642(Dongying District), 4.592(Shouguang City), 2.456(Hanting District) , 1.947(Guangrao Country), 1.678(Hekou District), 1.354(Changyi City), 0.707(Laizhou City) ,-0.576(Kenli Country), -2.249(Lijin Country), -2.358(Wudi Country), -2.879(Zhanhua Country), respectively.

2.2

Agent-based modeling

Construction of agent simulation project

The Repast-Simphony framework provided many other tools for assisting the model developer to create a model, but the standard model structure was based on these contexts and projections. Repast-Simphony was also a free and open source agent-based modeling toolkit that offers users a rich variety of features including the following content: an optional point-and-click model development environment, a pure Java point-and-click model execution environment, etc. The Repast S framework provided many other tools for assisting the model developer to create a model, but the standard model structure was based on these contexts and projections, so we selected Repast-Simphony program to clarify the agent simulation process [5,[START_REF] Howe | Containing Agents: Contexts, Projections, and Agents[END_REF][START_REF] North | Legacy Model Integration with Repast Simphony[END_REF][START_REF] Parker | Agent-Based Meta-Models[END_REF][START_REF] Tatara | An Introduction to Repast Modeling by Using a Simple Predator-Prey Example[END_REF] .

InformationNode simulation in the paper responded to the development situation of rural areas and agriculture information. In this study, these nodes resources given as Informatization energy indicated the strength changes of rural areas and agriculture information. A large number of agents walked in the space, and constantly increased the energy by the method of learning from their around agents. Energy nodes of rural areas and agriculture information would be consumed in one cycle, so the energy from rural area and agriculture information node was consumed when it died. During the energy transmission, Informatization node agents transmitted in accordance with the established rules. The node process simulation of rural areas and agriculture information was explored from the dual policy in the study, the unsealed link and analysis was developed by agent simulation. Finally, we constructed the agent behavior model.

InformationNode model was now fully defined by Repast-Simphony IDE. It contained a definition for a single agent type, a network projection, and a grid projection. We created agent elements of "InformationNode", the most often (and only) property and style are changed and the label property and enter "InformationNode" property was selected. 11 Informatization nodes, respectively, the energy of Informatization node had a certain change. Especially, in the case study, repast Simphony agent, the Math Operation for assigning a random number was selected as an important step, "Grid" and the dimensionality property is "2", and we defined the agent behavior according to the fundamental simulation steps, which included creating a "Deltademo" Model, creating a simple Repast model, running the simple Model, custom display properties, data sets and charts. Finally, the "delta_class" project was created, which included InformationNode agent, InformationNode groovy, etc.

Data processing and data analysis

To initialize the agent model was the first step of agent simulation process. When the model was initialized, agent parameter displays will be created and shown in the runtime window. Note that since no agent instances have been created yet, the simulation time would not run forward if the play button was pressed, as there were no scheduled actions. Agent instances may be created in the runtime window using the agent editor tool to connect the correlation nodes.

The agent behavior specified in this "Deltademo" was only reactive in nature, meaning that the agents would only do something based on a specific event occurring, in this case a reaction to a change in energy from an agent connected to it. The agents in the display can be probed by double clicking on them, and mainly the external response was inspected by the double-clicking mouse_event, implement of agent listen event, responded to the auto adapting.

Results and Analysis

The agent behavior that was defined should cause agents to connect to the first agent, and to change their energy property after 11 simulation ticks. Initialized program was carried out and the model run. Now the model can be run without first needing to make a change to an agent energy since the measured energy property was scheduled to be calculated every tick. Open the 2D Display, change the first Informatization Node's energy property to 100 and continue running the model. If the step simulation button was clicked until the tick count reaches 11, the next agent in the chain should change its energy from 300 to 200, to 100. Double click on the second agent to display its properties in the probe panel to verify this. Finally, run the model to observer the propagation of the change in energy to the downstream nodes. To test the chart, switch back to the 2D Display, probe an agent and change its energy from 300 to 200, to 100. Now run the simulation and observer, the energy changes were recorded on the chart.

The transmission mode was presented in Fig. 1 from the small value(from 100 to 200) to the high value, The transmission mode was presented in Fig. 2 from the middle value to high value(from 200 to 300), the kind of energy transmission mode was extracted from 11 country levels referred to Fig. 3.

The results from Fig. 5 showed that the energy of rural areas and agriculture information had an obvious gradient characteristics, which presented the dynamic changes of 11 Informatization Nodes located in the Yellow River Delta "and" the Blue Economic Zone of Peninsula". Each Informatization Node had changed characteristics itself, and the scope of Informatization energy had the certain rule from 100 to 300 on the whole, but there is the fluctuation characteristics round the threshold, such as 300,200,100 in the study case, respectively.

Conclusions and Discussion

Agent-based simulation of rural areas and agriculture informatization was explored in the study, and some conclusions could be drawn as follows.

The paper proposed that the rural area and agriculture information level was measured by 13 indicators in the overlay 11 country levels located in case regions. The study constructed the energy nodes agents involved in agent context, network and grid of rural area and agriculture information. Furthermore, in dual policy mechanism driving of "high-efficient ecological zone in Yellow River delta "and" the Blue Economic Zone of Peninsula", we also developed that the spatial process of dissipation of energy of located in 11 informatization Nodes was obvious described by the agent simulation with Repast-S IDE, and analyzed the unsealed link among nodes. The article put forward the agent energy transmission mode from 11 informatization Nodes, the energy of rural areas and agriculture information has an obvious gradient characteristics, which presented the dynamic changes of 11 informatization Nodes; each informatization Node had change characteristics itself, but there was the fluctuation characteristics round the threshold, such as 300,200,100, respectively, which responded to the gradient changes of informatization energy transmission.

Fig. 1 Fig. 3

 13 Fig. 1 Energy transmission mode of rural area and agriculture information (from 100 to 300) (left) Fig. 2 Energy transmission mode of rural area and agriculture information (from 200 to 300) (right)

2.1 Indicator system of rural areas and agriculture information 11

  country units from the overlay regions of Yellow River Delta high-efficiency ecological zone and blue economic zone of peninsula, including Dongying District, Shouguang City, Hanting District, Guangrao Country, Hekou District, Changyi City, Laizhou City, Kenli Country, Lijin Country, Wudi Country and Zhanhua Country in Shandong province. The comprehensive development of rural areas and agriculture information level in overlay country level is a crucial part of the National Demonstration Province of rural areas and agriculture information in the 11 th and 12 th


Huang Ting

Jiang Sicheng

Influence of Digital Computer Technology on Architectural Design Teaching Mode

Keywords: digital technology, computer aided architectural design, architectural design, teaching mode

This paper starts from the influence of CAAD system on different stages of architectural design and describes the application of digital technology in architectural design based on the development status of architectural design; meanwhile analyzes the teaching status of domestic computer aided architectural design curriculum and existing problems; and discusses its influence on architectural design field and even the educational pattern of architectural design major in combination with new features of the development of the current construction industry and computer aided architectural design technology.The emphasis lies in proposing constructive instructions for the reform of educational pattern of architectural design major in China.

Introduction

No digital computer technology in any era has such strong impact on architectural design, architectural teaching and practice. "Image architecture, digital simulation and virtual scene" etc. have gradually become "progressive" architectural design nouns. Ranging from computer aided drawing (CAD) to computer aided architectural design (CAAD), architecture has changed in the reform of design means, tools and medium. We can be more clear about how architectural design teaching mode should adapt to such reform by analyzing the influence of digital computer technology on architectural design. The change of design object results in the change of the role of architect and the teaching orientation of architecture major. New architecture and even new architect emerge at the right moment.

Application of digital technology in architectural design and its influence on design thinking 2.1 Application of digital technology in architectural design

The application of digital computer technology in architectural design not only involves drawing, model, animation, network and free form, but also reaches various fields in the process of architectural construction such as building construction, structural design and environmental index design.

Architect Frank Gehry used French aviation industrial manufacturing aircraft computer software "CATIA" system to construct architecture work. Digital means make architecture work with irregular shape a reality. In the past, Gehry always thought that model and drawing were easier to express architecture visually than computer. However, with the deepening of inspiration degree of his work, traditional design methods can hardly bear the great pressure brought by fantastical notion about shape, causing Gehry to gradually practice and finally completely accept computer. In his work Disney Concert Hall, the external form of the main part of the whole building develops completely according to acoustic design result; the internal spatial scale of the room is adjusted according to the sound vibration time evaluated by digital technology, including the measurement of air duct curvature, change of luminous environment in one day and wind load analysis etc. However, Eisenman applied computer in a different way. He no longer gave the concept of "computer aided", but conducted architectural design directly on computer. They represent two different trends of using computer for design.

Digital virtual reality technology is a computer system that can create and manifest virtual world. The application of VR technology in the process of architectural design allows the design process to be visual and architects to fully experience advantages and disadvantages of the internal functional layout and external environmental design of buildings as if they are staying in the place to be constructed and helps architects to better verify the correctness and feasibility of design.

Influence of digital technology on architectural design thinking model

For a long time, graphical information is the main medium of design and expression of architectural space. It plays an irreplaceable role in the process of formation, analysis and professional expression of conception of building scheme.

Professional technological means and tools of graphical information often influence design thinking. As a professional thinking model, the traditional graphical thinking mode makes the content object and professional design information of architectural design closely connected through a series of links such as drafting, model making and drawing formation and modification. Digital technology represented by computer aided design can transfer this process to virtual 3D digital world. This situation is called as "digital thinking". In the early stage of technological development, design thinking under digital technology does not support the rapid development of concept directly in the thinking process of designers. Therefore, they used to only accurately describe, refine and file concepts with complete development. Currently, digital technology has made substantive progress. Besides allowing architects to have more visual abstract thinking closer to the reality, more importantly, it can break through regular design rules and allow architects to get breakthrough and innovation in technology and find poetic shape pursuit. The conception of architectural space can have freedom and randomness like sculpture. Moreover, it may update design thinking and method and form architectural digital information model with overall integration, more dynamic participation and wide horizontal cooperation etc.

Teaching situation of traditional computer aided architectural design curriculum

Currently, the teaching of computer aided architectural design curriculum is led mainly according to two different clues domestically. One is design expression, including 2D architectural drawing and 3D modeling, 3D architectural rendering and image processing, multi-media architectural expression and demonstration [START_REF] Gefeng | Digital Means and Virtual Reality Technology in Architectural Design -Application and How to Promote Innovation and Development of Architectural Design[END_REF] . For

How to reform architectural design teaching mode so as to give full play to advantages of architecture major in digital times

The author thinks that CAD teaching throughout architecture major should not stand on expression clue or conception clue because expression and conception should be basic qualities of architectural designers. Our teaching of architecture should be led by requirements of the market for architects with the clue of the process in which students accept and learn architectural design. Complete CAD teaching should contain three parts: part 1 includes brief introduction to the development history of architectural CAD technology, application situation, software and hardware system and main technologies; part 2 includes computer aided analysis in terms of architectural environment, shape, space and physical characteristics; part 3 is 2D, 3D and multi-media computer performance of design achievements. Currently, in terms of architectural CAD course arrangement in many universities, computer aided architectural design expression occupies the majority of class hours. Some universities even incorporate architectural CAD into design expression courses in teaching curriculum system planning. This obviously neglects the important role of basic theories of computer aided architectural design and computer aided architectural design concept in architecture major.

As a professional teacher of architectural graphing and architectural design curriculum, the author brings forward his own opinions on CAD course teaching of architecture according to his years of teaching experience. As the first part of architectural CAD, basic theories of architectural CAD and contents of drawing part can be explained in combination with descriptive geometry and computer part of shadow and perspective in freshman year so as to help students establish the elementary contour of this technology. In this part, we can be oriented at practicality and teach in combination with small architectural design in basic courses of architectural design in freshman year so as to arouse students' learning interest and improve the operability of architectural CAD technology. Previously, most of us thought that students majoring in architecture should not touch computer too early, which is adverse to the cultivation of students' early architectural accomplishment.

The author thinks that, with the increasing development of computer today, if computer aided teaching is beneficial to the study of professional knowledge and training of professional skills and good for arousing students' learning enthusiasm and cultivating students' innovation ability, we should spare no effort to apply it. For the second part computer aided architectural design concept, we can gradually teach in stages and grades. For example, we can start from architectural design curriculum in sophomore year, conduct environmental simulation, spatial analysis, form conception Architecture is an integrated discipline. The education of architecture major shows the superiority of systematic cultivation of students majoring in architecture in multiple aspects such as color sense, relationship of composition of proportions, streamline functional space organization design, style design, structural form selection, building construction, building materials and architectural history. Digital technology is only a tool used in architectural design, which is conducive to producing more excellent architectural design works, accelerating architectural design mapping and improving architects' sense of 3D space. However, it cannot replace architectural design of architecture major based on system theory. Today, with increasingly wider computer aided architectural design, some students think that free basic skill training is not indispensable. It seems that computer can accomplish all work completed by manpower previously, resulting in sharp decrease of students' on-hand expression ability. This becomes a universal phenomenon in the department of architecture of various universities. In fact, when technologies become more advanced, people should attach more importance to the improvement of their own quality and ability.

Basic skills contain double meanings -graphic capability (ability of expression) and design ability. The cultivation of design ability mostly originates from the training process of the ability of expression. Therefore, proper use and correct understanding of computer technology will help students to learn architecture well more smoothly.

Conclusion

Though digital technology has been applied in architectural design for a short time, the change brought by it is very striking and it gradually becomes mature.

Ranging from program design drawing and working drawing in the early stage to 3D modeling and image processing to animation and virtual reality and the establishment of architectural information model, its major function is not impairing architects' creative activity but freeing architects with creative talent from a lot of tedious and repetitive work through the superiority of digital technology and allowing them to have more energy to be engaged in architectural creation.

  example, architecture major of the College of Architecture and Urban Planning, Guangzhou University currently provides architectural CAD teaching mainly in two parts -basic theories of architectural CAD and CAD aided drawing and making of computer aided architectural design sketch. The other is design concept. For example, Southeast University attempted to establish architectural design model by using computer as the design tool, simulate the whole process of program conception in three steps -volumetric model, structural model and architectural model and realize collaborative design with internet as the communication platform. Through the analysis on the application of computer in architectural design by two avant-garde American architects Gehry and Eisenman , we clearly realize that the influence of computer on architectural design not only involves expression. University academic advisory committee also advocates that architectural CAD should take the clue of design concept. However, it is restricted by many factors in actual operation, such as the lack of easy-to-learn, easy-to-use and effective computer software technology and guidance of architectural CAD experts. Moreover, it is better to synchronize computer aided architectural design and architectural design curriculum. Such operation has a high difficulty of coordination. Therefore, teaching with design expression as the clue is more often used currently.

  and achievement expression in the conception process of program design with SketchUp software, use it as the computer tool of aided architectural design concept and teach ideological contents of computer architectural design concept. Architectural design curriculum in junior year can further involve "VR" technology, architectural environment and architectural program modification with software "Ecotect". Less class hours are provided for the last part -computer design sketch making course. Students should mainly study on their own and teachers explain key points and difficult points of this technology in class and guide students to complete course work.Through such series of course learning, students can comprehensively understand architectural CAD technology. This technology is no longer only a drawing tool, but it actually applied in each stage of design.


Jinfeng Wang

Detang Zou

Jinwu Wang
email: cjinwuw@163.com

Xinlun Yang
email: dyang_xin_lun@126.com

Optimization Design on Deep-fertilization Fertilizer Amount Adjusting Mechanism for Paddy Field

Keywords: fertilizer applicator, fertilizer amount, adjustment, simulation, mechanism, optimization

In order to solve the deliquesced fertilizer adheres to fertilizer conveying pipe, and leads to fertilizer conveying pipe blocked , a kind of fertilizer amount adjusting mechanism of deep-fertilization machinery for paddy field was designed. This adjusting mechanism was taken as research object, the distance between hinge axis and the center of blade connection seat, the distance between hinge axis and sliding limited post axis, the rotation angular velocity of cam ring and the angular velocity of blade rotating around hinge axis were taken as objective function, the diameter of fertilizer through-hole, the number of blades and the changing range of curvature radius of guide chute were taken as constraint conditions, the aided design and analysis software for fertilizer amount adjusting mechanism was programmed by VB software, through which kinematics optimization was carried out for fertilizer amount adjusting mechanism. The obtained optimal parameter ranges are: the radius of inner ring of cam is 30mm, the number of blade is 6, the distance between the hinge axis and the center of blade connection seat is 47.5mm, the distance between hinge axis and sliding limited post axis is 12.5mm, the rotation angular velocity of cam ring is 25-35r/min, the angular velocity of blade rotating around hinge axis is 30-35r/min. According to optimization results, the fertilizer amount adjusting mechanism was simulated by Pro/E software, the simulation results were validated by experiment. The results show that the adjustable range of diameter of fertilizer through-hole for fertilizer amount adjusting mechanism is 9-56mm, the sliding limited post of blade and the guiding chute of cam ring have good sliding performance, and the designed fertilizer amount adjusting mechanism can satisfy the expected design requirements.

Introduction

Fertilizer is easily deliquescent chemical product, after moisture absorption, fertilizer has low flow ability, high adhesive ability, often adheres to fertilizer box and conveying fertilizer pipe, which results in technical issues, such as fertilization amount reduce, fertilization quality decline, or even conveying fertilizer pipe blockage, and cannot continue to operate, which reduce the operation efficiency of the equipment [START_REF] Zhaohe | Research on Fertilizer Deep Application Technology for Paddy Field[END_REF]. In order to solve the above problems, in recent years, the structure of configuration helical screw blades in fertilizer box and conveying fertilizer pipe emerges, but when operating, a large amount of deliquescent fertilizer still adheres to helical screw blades , the dredge effect is not ideal. Aiming at the existing technical problems, deep-fertilization mechanism for paddy fields was developed, which uses spiral wire instead of the helical screw blade, in this mechanism the traditional outer-fluted roller fertilizer distributor has been unable to matching, therefore, it is imminent to design a new fertilizer amount adjusting mechanism. In order to facilitate the adjustment of the amount of fertilizer, and the installment of spiral wire for deep-fertilization mechanism, a kind of fertilizer amount adjusting mechanism was designed, and its main parameters were optimized. Fertilizer amount adjusting mechanism was analyzed using kinematics theory, its mathematical model was developed, human-computer interaction simulation software was developed by VB software, which was used to obtain optimization parameters, structure design and simulation for fertilizer amount adjusting mechanism were carried out by Pro/E software, thus the movement of fertilizer amount adjusting mechanism was simulated [START_REF] Jinwu | Design and Experimental Investigation of the Liquid Fertilizer Applicator[END_REF][START_REF] Jinfeng | Design and Experiment on Liquid Fertilizer Device of Deep-fertilization[END_REF], the simulation results were validated by experiment.

Structure and Operation Principle

The structure of fertilizer amount adjusting mechanism is shown in figure 1. The hole 1 of hinge axis is set on the upper surface of blade connection seat 2, the lower side portion of the hinge axis 6 is plugged in the adjacent blade 3, annular assembly is composed by blade 3, the upper side portion of hinged axis 6 is plugged in hole 1 of hinge axis of the blade connection seat 2, annular assembly composed by blade 3 is mounted on the inner of blade connection seat 2, sliding limited post 7 is fixed on the lower side of blade 3, the cam ring 4, which has a guide chute 8, is fixed on the lower part of blade 3,sliding limited post 7 is plugged in the guide chute 8, the locked ring 5 is assembled in the lower side of blade connection seat 2 by thread, which is located in the lower part of cam ring 4. The handle 9 is inserted in slots 10 of blade connection seat, the inner part of handle 9 is connected to cam ring 4. When operating, the upper side of fertilizer amount adjusting mechanism was connected to fertilizer box; the lower side was connected to fertilization pipe, non-helical part of the longitudinal spiral wire passed through the center of fertilizer through-hole of fertilizer amount adjusting mechanism. When adjusting the amount of fertilizer, the handle 9 was moved in the slots 10 of blade connection seat, which drove cam ring 4 to rotate, under the control of guide chute 8, sliding limited post 7 made radial arc movement in the guide chute 8, the blade 3 moved around the hinge axis 6, the opening size of center hole was adjusted, which was composed by blade 3, the amount of fertilizer application was adjusted.

Mathematical Models

When fertilizer amount adjusting mechanism operating, the blade connection seat was fixed, cam ring was drove by adjusting handle, which realized the adjustment of the amount of fertilizer application. Handle and cam ring were fixed, the adjustment of the amount of fertilizer application can also be realized by rotating the blade connection seat, the latter method was used to develop mathematical model, as shown in figure 2. xoy is fixed reference system, x oy  is moving reference system, and the origin of coordinate system is coincide.

M is the pivot point of sliding limited post, the relative motion is fixed axis rotating around hinge axis hole of blade connection seat, translational motion is the blade connection seat rotating around cam ring. The relationship of absolute, relative and translational motion was established by coordinate transformation relation (1) [START_REF] Lifu | Composition Motion of a Point and the Method for Full-Process Analysis[END_REF][START_REF] Tang Hongchun | On the Establishment of System Info of Composite Movement of a Point [J][END_REF].

         (2)
R is the distance between hinge axis and the center of blade connection seat, unit: mm; 2  is the angular speed of blade rotating around hinge axis, unit: r / s; r is the distance between hinge axis and the axis of sliding limited post, unit: mm; t is time, unit: s. The equation of transport motion is shown as follow: 0

OO xx   , 0 OO yy   , 1 t

 

The equation of absolute motion of point M was obtained by equation ( 1) and ( 2), which is shown as follow.

1  is the rotation angular velocity of cam ring, unit: r / s.

                 (3)

4

Parameters Optimization

Objective Function and Constraint Conditions

In order to satisfy the fertilizer requirement of rice in different periods, the structure of fertilizer amount adjusting mechanism has the following requirements: (1) 30mm ≤ the diameter of the fertilizer through-hole ≤ 80mm; (2) the number of blade is greater than or equal to 6; (3) the guide chute of cam ring is smooth, curvature radius is greater than or equal to 15mm ; (4) the distance between hinge axis and the center of blade connection seat is greater than the diameter of fertilizer through-hole. In this case, taking lightweight of the fertilizer amount adjusting mechanism as target, thus the flexibility of adjustment was improved. The objective functions of fertilizer amount adjusting mechanism are the distance between hinge axis and the center of blade connection seat ( R ), the distance between hinge axis and the sliding limited post axis ( r ), the rotation angular velocity of cam ring ( 1  ) and the angular velocity of blade rotating around hinge axis (

 ). 2
The constraint conditions and objective functions are multi-variable nonlinear function, it is difficult to solve global optimal solution using traditional optimization methods, therefore, based on mathematical models and objective functions, on the premise of satisfy the constraint conditions, human-computer interaction simulation software was developed to optimize parameters by VB software [START_REF] Jinfeng | et al.Optimization Design on Pricking Hole Mechanism of Deep-fertilization Liquid Fertilizer Applicator[END_REF].

Human-Computer Interaction Simulation Software

The input parameters of software include a

, h , n , R , r , 1  and 2  , a
is the radius of inner ring of cam ring, h

is the width of cam ring, n is the number of blades. According to the variation of system parameters, software can output calculation parameters in real-time, and display the trajectory, meanwhile the absolute motion of the blade sliding limited post can also be simulated, as shown in figure 3.

When using this software, firstly enter a set of parameters based on experience, the computer calculates results, displays trajectory and simulates moving trajectory in real-time. Then based on these results, with people's experience and logical thinking to determine whether this set of parameters are good or not [START_REF] Jinwu | Dynamics Optimization for Pricking Hole Mechanism of Deep-Fertilization Liquid Fertilizer Applicator[END_REF][START_REF] Gaohong | Automatic Search of Pareto Solutions of Multi-objective for Rotary Transplanting Mechanism Kinematic[END_REF][START_REF] Wu Chuany | Optimization Design of Rice Trans Planter Separating-planting Mechanism with Visualization Human-computer Interaction Method[END_REF][START_REF] Xiaohuan | Optimal Design and Simulation on Pricking Hole Mechanism of Liquid Fertilizer Applicator[END_REF][START_REF] Jianjun | Optimization Design of Birotary Arm Type of Separating -transplanting Mechanism with Differential Eccentric Gear Train[END_REF][START_REF] Jiang | Mechanism and Performance Test of Pivot Turning System with Single Driving for Rice Combineharvester[END_REF][START_REF] Jianneng | Parameters Optimization of Transplanting Mechanism with Planetary Elliptic Gears for High-speed Transplanter[END_REF][START_REF] Wang | Experimental Study on Pricking Hole Performances of Deep Application Liquid Fertilizer Device[END_REF].

Analysis of the Influence of Variables on Results

As shown in simulation software:

(1) The rotation angular velocity of cam ring ( 1 ) affects the length of guide chute, which increases with the increase of 1  .

(2) The angular velocity of blades rotating around hinge axis ( 2 ) affects the changing rate of the area of adjusting fertilizer through-hole, which increases with the increase of 2  .

(3) k is the ratio of 1  and 2  , which influences curvature radius of the guide chute, curvature radius of the guide chute increase with the increase of k .

(4) The distance between hinge axis and the center of the blade connection seat ( R ) affects the mounting position of blade, the mounting position increases with the increase of R .

(5) The distance between hinge axis and the center of the blade connection seat ( R ),the distance between hinge axis and the sliding limited post axis( r ) and the number of blades( n ) can determine parts of blade size, the profile of blade can be determined in three-dimensional software .

Optimization Results

The optimization results which satisfy the movement requirements were obtained by software, as shown in table 1.

Structure Design and Simulation

Parameters optimization, trajectory simulation and structure schematic of the fertilizer amount adjusting mechanism were realized by human-computer interaction simulation software, which was developed by VB software, but the blade, the movement of cam ring and the inspection of interference problems for fertilizer amount adjusting mechanism need to be realized by three-dimensional solid modeling and simulation software. A set of optimized parameters were selected, which were a = 30mm, h = 25mm, n = 6, 1  = 25r/min, 2  = 30r/min, R = 47.5 and r =12.5 mm, fertilizer amount adjusting mechanism was designed by Pro / E, its structure simulation diagram is shown in figure 4.

Fig.4. Structure simulation diagram of fertilizer amount adjusting mechanism

Kinematics simulation was carried out for fertilizer amount adjusting mechanism by Pro / E, the profile of blade was modified, the blade assembly had no gap in the rotation process. The range of the diameter of fertilizer through-hole was adjusted from 7 mm to 56mm, as shown in figure 5. Interference test was carried out by Pro / E, the test results show that the moving process of the designed fertilizer amount adjustable mechanism has no interference, the sliding performance of the blade sliding limited post and the guide chute of cam ring is good, the designed fertilizer amount adjustable mechanism can meet the design requirements. Experimental Results and Analysis

Fertilizer amount adjusting mechanism was processed, and then the experiment was carried out. To turn the adjustment handle, the size of the diameter of fertilizer through-hole can be adjusted. The maximum diameter of fertilizer through-hole was 56mm, as shown in figure 6a. The minimum diameter of fertilizer through-hole was 9mm, as shown in figure 6b. The maximum value of the diameter of fertilizer through-hole was the same as the simulation results. the minimum value of the diameter of fertilizer through-hole was 2mm greater than the simulation results, A gap of 1mm in width between the two blades emerged in the process of adjusting the diameter of fertilizer through-hole smaller, which mainly due to the processing accuracy of the blade hinge axis and the position and verticality of the sliding limited post with the blade didn't satisfy the design accuracy requirements. In order to ensure that no gap appears between blades in the process of through-hole diameter changing, on the premise of without changing any other design parameters and improving the design accuracy, the number of blades can be increased by one.

Conclusions

(1) Aided design and analysis software for fertilizer amount adjusting mechanism was programmed by VB software, kinematics optimization was carried out using this software, the optimization results show that the radius of inner ring of cam is 30 mm, the number of blades is 6, the distance between hinge axis and the center of blade connection seat is 47.5mm, the distance between hinge axis and the axis of sliding limited post is 12.5mm,the angular velocity of cam ring is 25-35r/min, the angular velocity of blade rotating around hinge axis is 30-35r/min.

(2) According to kinematic optimization results, fertilizer amount adjusting mechanism was designed by Pro / E software, kinematics simulation was carried out for fertilizer amount adjusting mechanism. The simulation results show that the adjustable range of diameter of fertilizer through-hole is 7-56mm for fertilizer amount adjusting mechanism, the sliding performance of the blade sliding limited post and the guide chute of cam ring is good, the designed fertilizer amount adjusting mechanism can meet the design requirements.

(3) Experimental results show that the adjustable range of diameter of fertilizer through-hole is 9-56mm for fertilizer amount adjusting mechanism, which satisfies the design requirements, a gap of 1mm in width between the two blades emerged in the process of adjusting the diameter of fertilizer through-hole smaller, which mainly due to the processing accuracy didn't satisfy the design accuracy requirements. In order to ensure that no gap appears between the blades in the process of adjusting the diameter of fertilizer through-hole, the processing accuracy can be improved or the number of blades can be increased by one.

1 .Fig. 1 .

 11 Fig.1. Structure drawing of fertilizer amount adjusting mechanism

Fig. 2 .

 2 Fig.2. Movement analysis diagram of fertilizer amount adjusting mechanism cos sin sin cos

Fig. 3 .

 3 Fig.3. Optimization interface of visible human-computer interaction

Fig. 5 .

 5 Fig.5. Adjustable range of fertilizer amount adjusting mechanism in simulation

Fig. 6 .

 6 Fig.6. Adjustable range of fertilizer amount adjusting mechanism in experiment

Table .

 .

				1. Optimization results
	a /mm	h /mm	n	R /mm	1  /r . min -1	r /mm	2  /r . min -1
	30	25	6	47.5	25~35	12.5	30~35

Acknowledgment

This research was supported by National Natural Science Foundation of China (51205056), Youth Science Foundation of Heilongjiang Province (QC2011C007), Special Funds of Science and Technology Innovative Talents of Harbin (2012RFQXN004),Postdoctoral Fund Project of Heilongjiang Province (LBH-Z11222).


Jinfeng Wang

Detang Zou

Jinwu Wang
email: cjinwuw@163.com

Wei Zhou

Testing and Analysis of the Shear Modulus of Urea Granules

Keywords: urea, shear force, shear modulus, test 1

In order to study the interaction between urea and mechanical structure, using direct shear test method, the shear modulus of urea was tested by C-LM4 computer measurement and control shear force measuring instrument. The obtained test curves show that: extrusion makes the binding strength between urea molecules reduce, shear force peak emerge, then decline rapidly; as rolling granules and surrounding granules formed compression and friction resistance in contact surface along the direction of shear, shear force emerges rise again. At the test temperature 22℃, ambient humidity 45%, the density of urea granules 1.33 × 10 3 kg/m 3 , the values range of shear modulus of urea granules was measured, which was 0.23-0.3GPa.

Introduction

China is a big agricultural country, which is also a big fertilizer production and consumption country. Fertilizers play an important role in the development of agricultural production, especially in grain production. China uses less than 10% of the world's arable land to feed 22% of the world's population, which is inseparable with the contribution of fertilizer. For quite a long time, fertilizer is still an essential part to realizing agricultural sustainable development.

Rice is one of China's most important grain crops. Urea is widely applied in rice farming process, which is directly synthesized by raw materials of liquid ammonia and carbon dioxide under high temperature. The researches of urea are mainly concentrated in the application of urea in agriculture, the fertilizer proportion of urea and other fertilizers, the fertilizer utilization of urea, the synthesis of urea, and the chemical composition and so on, but the physical characteristics of urea are rarely researched [START_REF] Qiling | Study on Properties of PVA Plasticized Urea /Formamide[END_REF][START_REF] Cheng Zhongzhen | Performance Analysis and Comparison for Radial with Axial Flow Urea Reactors[END_REF]. Urea plays an important role in the process of rice farming, when applying fertilizer using paddy field fertilization machinery, urea often absorbs moisture, which results in urea has low flowability, adheres to fertilizer box and the conveying pipe, and leads to technical problems of fertilization rate reduced, fertilization quality decline, therefore, when researching the interaction of urea and mechanical structure, the physical characteristics of urea must be studied, such as density, elastic modulus, shear modulus and Poisson's ratio, etc. [START_REF] Junhong | Guo Yizhi et al. Study on 3-D Numerical Simulation for Soil Cutting with Large Deformation[END_REF][START_REF] Yunfei | Preparation and Properties of Porous Bioceramics Made of Bovine Bone[END_REF][START_REF] Hongming | Synthesis and Properties of Carbon Microtubes[END_REF]. The shear modulus of urea was measured using direct shear test method, the shear modulus of urea was obtained, which provides related research methods and data reference for the research of physical characteristics of urea [START_REF] Blunden | A High-Speed Shear Box Machine[END_REF][START_REF] Wheeler | Soil Dynamics of Single and Multiple Tines at Speeds Up to 20 km/h[END_REF][START_REF] Onwualu | Draught and Vertical Forces Obtained from Dynamic Soil Cutting by Plane Tillage Tools[END_REF][START_REF] Mootaz | 3D Dynamic Analysis of Soil-Tool Interaction Using the Finite Element Method[END_REF]. Click the "up" button of the measurement and control program of the computer, the activity shear frame of shear force measuring instrument was raised, which made the distance between the underneath of activity shear frame and the square hole of fixed shear-slice was more than 40mm. Urea granules, which will be measured, were fixed on shear-slice, click the "down" button, the instrument started to shear urea granules, when urea granules were shear off, the test was over. Measurement and control program of computer can record experiment data, and display curves.

Materials and Methods

Experimental Equipment

Shear modulus test equipment was mainly composed by shear force measuring instrument, data lines, measurement and control program.

Shear force measuring instrument. C-LM4 computer measurement and control shear force measuring instrument was used, which was developed by northeast agricultural university, this instrument can measure seed, fertilizer and food from 0.05 N to 250N, the measurement accuracy was <± 1%, the shear speed was 5 mm / s, the voltage was 220V, frequency was 50Hz, the input power of electric machine was 20W.

Measurement

Experimental Materials

Experimental material is urea granules, which has bigger structure size. Circular urea fertilizer was grounded into cube by file and sandpaper, the length of cube was 2mm, 2.5mm, 3mm, 3.5mm, 4mm and 4.5mm,which were taken as test samples, the test temperature was 22℃, ambient humidity was 45%, the density of urea particle was 1.33 × 10 3 kg/m 3 .

Experimental Methods

Experimental method of shear modulus of urea was direct shear, the obtained data were the changing curves of the time and shear force by shear force measuring instrument, the line segment of linear elastic deformation was identified on the timeshear force curve [START_REF] Karmakar | Experimental Validation of Computational Fluid Dynamics Modeling for Narrow Tillage Tool Draft[END_REF][START_REF] Yang | Dynamics Simulation of Direct Shear Test[END_REF], according to equation ( 1), shear modulus G was obtained as follow:

Q A d Q kd G v t d vA t vA            (1)
Where Q  is the increment of shear force when urea granules linear elastic deformation, unit: N;

A is the area of shear surface urea granules, unit: mm 2 ; t  is the increment of time when urea granules linear elastic deformation, unit: s; v is the moving velocity of activity shear frame, unit: mm/s; vt  is the increment of displacement when urea granules linear elastic deformation , unit: mm; d is the size of urea granules sample, unit: mm; k is the ratio of the shear force increment and the time increment when urea granules linear elastic deformation, namely the slope of the linear elastic deformation on the time -shear force curve.

Results and Analysis

Different size of urea granules were selected to make shear test, the shear modulus of urea granules were measured, but due to the limited length of paper, only urea granules with side length 3.5mm and 3mm were analyzed in this paper. Three urea granules with side length 3.5mm were selected to do shear test, the test curves were obtained by measurement and control program, as shown in figure 2. Three urea granules with side length 3mm were selected to do shear test, the test curves were obtained by measurement and control program, as shown in figure 3.

Fig. 3. The course of shear force -time of urea granules with side length 3mm

As shown in figure 2 and figures 3, With the moving of activity shear frame of shear force measuring instrument, firstly shear force increased rapidly, and reached a maximum, and then reduced rapidly, which had the same curve changing rule with the existing shear physical test. When activity shear frame contacted with urea granules, activity shear frame and fixed shear-slice surface had compression force to urea granules, but the action force between them was small, stress distribution of urea granules was uniform. With the moving of activity shear frame, sheared part formed shear zone with longitudinal width about 1mm,the extrusion force of activity shear frame to urea granules was enhanced, which made urea molecules in central part of the shear zone lost link, and appeared crack, shear force continued to increase, the peak of shear force appeared, and then decreased rapidly. With the increase of movement amount of activity shear frame, shear force of activity shear frame to urea granules further strengthened, shear zone was further squeezed, parts of granules, which lost connection force, rolled along the shear direction, and contacted with surrounding granules to form compression and friction resistance, shear force increased again. Finally, under the action of activity shear frame, the rest urea granules were further cracked to overcome frictional force between urea granules, which made urea granules between activity shear frames and fixed shear-slice staggered, shear force decreased to zero, urea granules were sheared off.

The obtained test data from the measurement and control program were fitted by Excel software, the curves of test pointsshear force were obtained. The curve of test points-shear force of urea granules with side length 3.5mm was obtained, as shown in figure 4, The curve of test pointsshear force of urea granules with side length 3mm was obtained, as shown in figure 5. In figure 4 and figure 5, the horizontal axis indicated test points, there were 200 test points, the vertical axis indicated shear force. As the measurement and control program recorded a test point data every 0.01s, while the moving speed of activity shear frame of the shear force measuring instrument was 0.5mm / s, so the horizontal axis can be converted into time, and also can be converted into displacement.

As shown in figure 5, the changing rule of the curve of test points -shear force was very similar to figure 4, but different shear force peaks. In order to obtain the shear modulus of urea granules, a straight line should be identified on the test points -shear force curve before the first peak appeared. As shown in equation ( 1), the slope of this straight line can reflect the shear modulus of urea granules. Test points from 0 to 20 can't be selected as straight-line segment, because generally instrument exist error in the measurement range of 10% or urea granules specimen was not standard.

In order to find a segment of straight line on the test points -shear force curve, the experimental data of shear force, which present linear changing rule, were obtained from 6 groups test results of urea granules with side length of 3.5mm and 3mm by the measurement and control program, the test data were analyzed by Design-Expert6.0.1 software.

Taking shear force as performance index, test time as factor, 25-30 data of test points of shear force were selected to fit curve, the function relationship between shear force and time was obtained, test data are shown in table 1. Variance analysis showed that model was significant, the time t was a valid model items. The obtained regression equations is shown as follow: Q=496.03t-17.21

(2)

The slope of curve was 496.03 in equation ( 2), which was substituted into equation (1) , the value of shear modulus G was obtained ,which was 2.83 × 10 7 Pa.

The fitting regression curve of the influence of the test time to shear force was obtained for urea granules with side length 3mm by Design-Expert 6.0.1 software, as shown in figure 7. Variance analysis showed that model was significant, the time t was a valid model items. The obtained regression equations is shown as follow

DESIGN-EXPERT

Q=450.09t-19.67 (3)
The slope of curve was 450.09 in equation ( 3),which was substituted into equation ( 1) , the value of shear modulus G was obtained, which is 3 × 10 7 Pa. Urea granules with side length 2-4.5mm were selected to do experiment, the obtained values range of the shear modulus G is 2.3 × 10 7 Pa -3× 10 7 Pa.

Conclusions

(1) Urea granules was sheared off by C-LM4 computer measurement and control shear force measuring instrument, which was developed by northeast agricultural university, test data were obtained and test curves were displayed by measurement and control program of equipment. The obtained test curves show that: the compression between shear frame and urea granules makes the binding strength between urea molecules reduce, the peak of shear force emerge, then decline rapidly; as the rolling granules and surrounding granules formed compression and frictional shear force in contact surface along the shear direction, shear force emerges rise again.

(2) The obtained test data from the measurement and control program were fitted by Excel software, the test pointsshear force curves were obtained. The regression equation of urea granules in the elastic deformation was fitted by Design-Expert software, the shear modulus of urea granules with side length 3.5mm and 3mm are respectively 2.83 × 10 7 Pa and 3× 10 7 Pa.

(3) At the test temperature 22℃, ambient humidity 45%, the density of urea particle 1.33 × 10 3 kg/m 3 , the values range of shear modulus of urea granules was measured by shear force measuring instrument ,which is from 2.3 × 10 7 Pa to 3× 10 7 Pa.

2 . 1

 21 Structure and Working Principle of Test EquipmentShear modulus test equipment includes shear force measuring instrument, data lines, measurement and control program, as shown in figure1. The fixed shear-slice of the shear force measuring instrument was replaced by shear-slice of urea granules, shear force measuring instrument was connected with computer using dedicated data line, one end of data line was inserted into the computer USB port, the other end was connected to the rear 9-hole D-type data communication interface of the shear force measuring instrument. To open the power switch of shear force measuring instrument, and start the measuring and control program on the computer.

Fig. 1 .

 1 Fig. 1. Test equipment and test process of shear modulus

Fig. 2 .

 2 Fig. 2. The course of shear force -time of urea granules with side length 3.5mm

Fig. 4 .Fig. 5 .

 45 Fig. 4. Changing curves of test pointsshear force of urea granules with side length 3.5mm

Fig. 6 .

 6 Fig.6. The fitting regression curve of the influence of the test time to shear force for urea granules with side length 3.5mm

Fig. 7 .

 7 Fig. 7. The fitting regression curve of the influence of the test time to shear force for urea granules with side length 3mm

  and control program. Measurement and control program has operation control, test curve display, peak force maintain, test data management and other functions. The display window of test curve shows the time -shear force curve, which can display multiple samples test curve simultaneously, and has coordinate zoom function. Sampling rate of the measurement and control program is 100 test points / s, sampling interval is 0.01 s, and recorded data are stored into computer with Excel file format.

Table 1 .

 1 Test data of shear forceThe fitting regression curve of the influence of the test time to shear force was obtained for urea granules with side length 3.5mm by Design-Expert 6.0.1 software, as shown in figure6.

	test points	time/s	1		3.5×3.5/mm 2 2	shear force/N 3 1	3×3/mm 2 2	3
	25	0.115	40.2504	40.3289	39.4166	32.8009	29.9266	33.3914
	26	0.12	43.0561	41.6140	40.6919	33.5293	31.5293	36.3552
	27	0.125	46.1462	45.7735	42.5950	35.9144	35.8581	39.0242
	28	0.13	49.4620	49.1187	44.5570	39.1125	39.0168	41.4485
	29	0.135	51.8066	51.6889	46.4307	41.6435	39.3326	42.4581
	30	0.14	53.2094	54.0727	48.3339	44.4099	41.7269	44.2253
		DESIGN-EXPERT Plot			One Factor Plot
		Shear force		54.0727
		X = A: time
		Design Points	50.1903
				force	46.308
				Shear
				42.4256
				38.5432
						0.115	0.120	0.125	0.130	0.135	0.140
								A: time

Acknowledgment

This research was supported by National Natural Science Foundation of China (51205056), Youth Science Foundation of Heilongjiang Province (QC2011C007), Special Funds of Science and Technology Innovative Talents of Harbin (2012RFQXN004), Postdoctoral Fund Project of Heilongjiang Province (LBH-Z11222).


Fang Chengjun

Hua Chunjian

Advances in the Application of Image Processing Fruit Grading

Keywords: Image-processing, Computer-vision, Fruit Grading

In the perspective of actual production, the paper presents the advances in the application of image processing fruit grading from several aspects, such as processing precision and processing speed of image processing technology. Furthermore, the different algorithms about detecting size, shape, color and defects are combined effectively to reduce the complexity of each algorithm and achieve a balance between the processing precision and processing speed are keys to automatic apple grading.

Introduction

In the recent decade, most of the worldwide apple products are made in China. China produced 3598 million tons of apples every year, while the second-placed U.S.A has the production of 427 million tons. However, China still has a low export volume of apples, 103.47 million tons in 2011, accounts, only 2.87% of the yearly production. And it also is reduced by 7.86% year-on-year. By the investigation of the consequence, the first reason is the high quantity but low quality of products. Secondly, there is no any application which is efficient and high precision in grading apples, so the graded good quality apples are difficult to find in markets. At the last, the agricultural labor force is transferring to other industries in great quantities, the intelligent machine is needed to liberate human from heavy and monotonous work. The existing method of fruit grading can be divided into two categories, one is the mechanical classification and the other one is based on optical measurement device. The former one is mainly judged by hole or lever, the latter judge the diameter and size of fruit by photoelectric detector or test the surface color to judge the maturity. However, the fruit grading method based on machine vision has advances in the application. According to analyzing images by cameras, it is easily to calculate a lot of parameters such as area, diameter and so on. It can test size, color, defects and bruise in one time. In addition, the biggest advantage of machine vision grading is the high efficiency regardless of the influence of subject factor. Therefore, it is urgent to improve the technology of apple grading, especially the technology which can be applied to the actual production. For these, the paper reviews the apple grading technology in the world based on the image processing.

Research Situation

It is widely acknowledged that apples' size, shape, color and defects are concerned separately in the existing technology of grading apples. Under experimental conditions, the ideal accuracy and processing speed can be achieved. Consequently, the paper summarized the current technology inspecting the processing precision and speed.

Processing Precision

Miller developed a color computer vision system to inspect and grade peaches' surface. Digital color images of peaches were acquired as the fruit moved on a belt conveyor. Image analysis algorithms were developed to compare peach ground color to reference peach maturity colors estimating the amount of blushed surface area. Ground color maturity classification with the computer vision system agreed with manual maturity classification in 54% of the test samples, and was within one color standard in 88% of the samples. Correlation coefficient between machine and manual estimates of blush surface area was 0.92 [START_REF] Miller | A color vision system for peach grading[END_REF] . Leemans V. etc. presented a hierarchical grading method applied to Jonagold apples. Several images covering the whole surface of the fruits were acquired thanks to a prototype grading machine. These images were then segmented and the features of the defects were extracted. During a learning procedure, the objects were classified into clusters by k-mean clustering. The classification probabilities of the objects were summarized and on this basis the fruits were graded using quadratic discriminant analysis. The fruits were correctly graded with a rate of 73%. The errors were found in the segmentation of the defects or for a particular wound, in a confusion with the calyx end [START_REF] Leemans | A real-time grading method of apple base on features extracted from defects[END_REF] . Devrim Unay etc. presented a novel application work for grading of apple fruits by machine vision. Following precise segmentation of defects by minimal confusion with stem/calyx areas on multispectral images, statistical, textural and geometric features are extracted from the segmented area. Using these features, statistical and syntactical classifiers are trained for two-and multi-category grading of the fruits. Results showed that feature selection provided improved performance by retaining only the important features, and statistical classifiers outperformed their syntactical counterparts. Compared to the state-of-the-art, their two-category grading solution achieved better recognition rates (93.5% overall accuracy). In this work, they further provided a more realistic multicategory grading solution, where different classification architectures are evaluated.

Their observations show that the single-classifier architecture is computationally less demanding, while the cascaded one is more accurate [START_REF] Devrim | Automatic grading of Bi-colored apples by multispectral machine vision[END_REF] . Zhao Jing took the advantage of reference shape analysis and artificial neural network to identify and classify apples' shape, which improved the accuracy rate to 93%. On the basis of analysis of fruit shapes, 6 characteristic parameter is proposed to describe fruit shape, which include diameter, continuity, curvature and the symmetry of the former three-parameter [START_REF] Jing | Research on method of Fruit Shape Recognition[END_REF] . Wang Jian etc. took different quality level apple color pictures by digital camera. Using R color branch to determine threshold value after image smoothing, they carried through image segment and erosion, then transferred RGB to HSL. At last, the true apple area was obtained by means of pixel points transform method taking count of the number of pixels on the projection. The results showed that the method was proper for the apple sorting based on computer vision, and it had a result with a veracity of 89.8% compared with manual judgment [START_REF] Jian | Study on Computer Vision Grading Based on Apple Coloration Area[END_REF] . Rao Xiuqin etc. put forward a grading method to improve the quality of fruits. They made use of HIS color model to analyze the fruit image after segmentation and calculated the principal component (PC) of the H component histogram weighted by the fruit surface area. And then the average values of the most significant MPCs of the red and yellow sample groups were calculated respectively, which were used as the centers of the two sample groups to setup a grade model. A fruit was graded to the red group if the Mahalanobis distance between the fruit and the center of the red sample group was less than that between the fruit and the center of the yellow group, or it was graded to the yellow group. The test results of 800 navel orange images showed that the first and the second PCs of the H component histogram weighted by the fruit surface area were enough to grade a fruit, and the total error was only 1.75% [START_REF] Rao Xiuqin | Grading a fruit by its' surface color[END_REF] . Liu Yanglong studied the fruit shape classification . Wavelet descriptor is extracted to describe the fruit shape from wavelet transform of the normalized fruit radius sequence .Matching rates of different wavelet and different number of coefficients are analyzed on the reconstruction of the fruit border.The dimensions of shape feature are reduced using kernel principal component analysis (KPCA).The research shows that fruit shapes can be describe well by 36 points of Biorthogonal wavelet transform. Matching ratio between the shape and the reality is 98.64%. Finally, dynamic nearest neighbor-clustering algorithm is used to make the radial basis function (RBF) neural network as fruit shape classifier.The results show that the classification accuracy is 90% while the superior fruit recognition rate is 93.75% among the experiment. Experiments between wavelet descriptor and Fourier descriptor are compared [START_REF] Yanglong | Research on the shape grading of fruit based on the DSP machine vision[END_REF] .Further, Li Junliang researches the relationship between the external features such as size color shape texture and internal quality of sugar. BP neural network and SVM (Support Vector Machine) are adopted to establish sugar classification model according to external features. The result shows that external features and internal quality of sugar have complicate non-linear relation. The accuracy rate of SVM is 82% which is higher than 64% of BP neural network classification model. At last, principal component features were extracted out from the NIR (Near Infrared Reflection) spectrophotometer as apples' internal features. Then outward features and internal features were fused with SVM to constructed sorting model of apples' sugar. The result shows that the sorting model with fusion technology is 91% better than the model with single sensor [START_REF] Junliang | Research on the shape grading of fruit based on the machine vision and NIRS[END_REF] .

In the process of apple image detection, the largest factor which affects the precision is miscalculation of fruit stalk and calyx. Because of similarity of the fruit stalk, calyx and defects in the image, it is easily judge for defects. P.Jancsok proposed a new method to identify stem-end/calyx from bruises. According their method, a hyper spectral imaging system was used for separating stem-end/calyx regions from true bruises. Based on principal component analysis (PCA) of the hyper spectral images, multiple effective wave bands were selected. Afterwards, PCA and imageprocessing techniques were applied to the multispectral images. The stem-end/calyx regions were identified and distinguished from the cheek surfaces by analyzing the contour features of the first principal component score images. None of the sound tissue was misclassified as a stem-end or calyx region for both cultivars apples. In the investigated samples, all of the stem-end/calyx presented in the images were correctly recognized for the 'Golden Delicious' apples and 98 33% for 'Jonagold' apples. Les s than 3% of bruises were misclassified as stem -end/calyx regions for both cultivars apples [START_REF] Xing | Stem-end/Calyx Identification on Apples using Contour Analysis in Multi-spectral Images[END_REF] . Zhang Wenying etc. did something similar. According to the characteristics of apple stem, they used block scanning to judge stem. In addition, they found out the damaged area as well as stem and fruit calyx by analyzing the different reflection characteristics of the damaged surface and healthy surface, and the statistical properties of different gray level value of pixel points. It was 100% accuracy rate on 15 fruit stalk pictures, while the accuracy of 90 stem picture was 88%. Experiment results proved that the method for detecting detected surface is efficient [START_REF] Wenying | Study on Detecting Methods for Apple Stemand Defected Surface with Computer Vision[END_REF] . Song Yihuan etc. proposed a method to distinguish the apple stem/calyx and defect based on DT-CWT (Dual Tree Complex Wavelet Transform) and LS-SVM (Least Squares Support Vector Machine). They took apple image decomposition with DT-CWT and constructed feature vectors with the mean and variance of the transformed high frequency subband coefficients, then classified with LS-SVM. After the experiment on 180 apple images, the result showed that it had the best effect of extracting texture features with wavelet decomposition classifying by means of 3 layers DT-CWT to 64*64 image. The accuracy rate was 95.6% [START_REF] Yihuan | Apple stem/calyx and defect discrimination using DT-CWT and LS-SVM[END_REF] . The hyper spectral imaging technology was proposed to detect the subtle bruises on fruits by Zhao Jiewen. Apples were adopted as the experimental object . The apples hyper spectral images between 500 nm and 900nm wavelength were analyzed via the principal components analysis,and the feature images under 547nm wavelength were selected to detect the bruises on apples.The asymmetric brightness of the images was eliminated with asymmetric second difference subsequently. Finally, the feature of bruise was extracted through appropriate image processing.The experimental results show that detecting subtle bruises on fruits on1ine with hyper spectral imaging technology is realized and the accuracy is 88.57% [START_REF] Zhao Jiewen | Detecting Subtle Bruises on Fruits with Hyper-spectral Imaging[END_REF] .

Processing Speed

Li Qingzhong etc. proposed a fast approach for box-dimension estimation based on a dual-pyramid data structure. For the suspicious defect area in fruit images, they utilized traditional fractal dimension and 4 oriented fractal dimensions as input values. They calculated with the proposed fast calculation method, and then a BP neural network was designed for identifying fruit defect area and stem, calyx concave area. Test results proved that the rate of correct classification is 93% and the executing time of microcomputer for recognition of one undefined blob on the surface of apple is 4~7ms [START_REF] Qingzhong | A Fast Identification Method for Fruit Surface Defect Based on Fractal Characters[END_REF] . Shen Mingxia etc. adopted fuzzy threshold segmentation to process the original image. The process time of this method in 68 s, while the Ostu method uses 123 s. Obviously, the speed of this method had its advantage [START_REF] Mingxia | Fuzzy Threshold Segmentation Method in Quality Detection of Fruit[END_REF] . In the light of the characteristics and requirement of real-time inspection and grading, the continuous area-scans approach was put forward to acquire the image of fruits from time to time in a time-series manner by Huang Yonglin etc. The test results verified that this system could grab 12 frames per second with the triggering from the proximity sensors [START_REF] Yibin | Methodology for images grabbing of massive numbers of moving fruits[END_REF] .Zhang Feng etc. selected roundness, volume and the gray-level histogram of R G B component as apple quality evaluation index. They calculated roundness and volume by apple binarization image. Compared the index of images' each R G B grayscale histogram with the standard apple, it can automatically detect appearance and quality of apples. It costs 0.9s to detect an apple which satisfied the requirement of the real-time detection. This technique can be used for the apple packaging product line, and also can be used for appearance quality detection of agricultural products similarly [START_REF] Feng | External quality detection of apples using image processing technology[END_REF] .

Combined with Processing Accuracy and Speed

Feng Bin etc. set up a standard sphere gray model, which can realize fruit defect segmentation. In addition, they used the single threshold while the threshold boundaries don't need to be considered. For recognition of stem, calyx and defect, they made full use of the influence of its space shape to gray feature, using Fourier transform to determine shape of gray line, which become a satisfied result. After identified 50 stems and 50 calyxes, the accuracy was higher than 90%. This method had a small amount of calculation and fast speed, which can meet the requirement of the computer vision on-line detection of fruit [START_REF] Bin | Study on Identifying Measurement About Default of Fruit in Computer Vision[END_REF] . Zhang Yajing etc. proposed a method using intensity and color information for separating adjoined apples. Firstly, they used Lab model to segment apple image, followed by each segmented area was calculated to judge whether they were adjoined area or not. After calculating the light information within adjoined area, the segment adjoined area according light spot produced by brightness, which can shield the noise outside the area. However, the unique brightness information in the area can be utilized to segment adjoined apples effectively. Experimental results showed that the recognition rate was more than 92.89%, and it was simple and rapid. Furthermore, the average image recognition time was less than 0.5 s [START_REF] Yajing | Separating Adjoined Apples Based on Machine Vision And Information Fusion[END_REF] .

Conclusions and Prospect

In conclusion, since scholars have done a number of researches on apples during a long time, which comes various new algorithms and application methods. However, in practice, there is still a lot details to be improved. Therefore, the mainly problems of existing technology and the future direction of development can be summarized as the following points:

(1) Single detection feature. The existing technology always aims at detecting one single feature such as shape, weight, color or defeats. However, we prospect to grade in the minimum times of detection that we can improve production efficiency in the work site. Therefore, we would like to obtain enough information at one time.

(2) Balance between speed and accuracy. It is able to reach the ideal detection speed and accuracy under laboratory conditions, but either can meet the actual production requirement. Therefore, we need to reduce the complexity of the existing algorithm, yet we should not have much influence on the accuracy, which we must find a balance between speed and accuracy.

(3) We can consider using color image processing techniques because of the diversity of apples' surface color. Under these color images, it will be easier to judge stalk and calyx, avoiding mistaken for surface defects, as well as the apparent color and defects. Above all, the speed is still the problem to be solved yet.

(4) The lack of suitable mechanical structure for mass processing. Since most of the existing technologies are basically carried out under laboratory conditions, yet there are many uncertain factors in the process of production, thus we need to work out the suitable mechanical structure for image processing which makes the produce conditions as close as possible to the laboratory conditions.

In conclusion, simplifying the existing algorithms and fusing different detection algorithm to form higher speed and higher precision detection algorithm is the development direction in future image processing technology in practical production, which is supported by appropriate mechanical structure.

Acknowledgment

This work was supported by the National Natural Science Foundation of China (No. 61104213) and the Program for Innovative Research Team of Jiangnan University (No. 2009CXTD01).


Yujian Yang

Huaijun Ruan

Jingling Li

Lei Wang

The Comprehensive Assessment of Planting Elements based on Analytic Hierarchy Process

Keywords:

There were many factors having an effect on planting development, this paper designed an indicator system for planting assessment, mainly including three kinds of essential sub-system elements, they were resource subsystem, information and energy sub-system and social-economic sub-system, the detailed indicator system involved in 8 concrete indicators from the three sub-systems. In the way, a set of reasonable indicator system of planting assessment was proposed on township/town scale, there was the characteristics involved in rural areas and agriculture information introduced in the case of indicator system. Based on it, the paper constructed the hierarchical structure model of the planting elements assessment, the weight of each indicator was calculated through AHP method. The study results showed that the planting elements development level from the comprehensive assessment was Juzhen township, Fangsi town, Shizhong subdistrict office, Xinzhai town,Xindian town, Zhangzhuang town , Liangjia town , Anren town, Lunzhen town, Shiliwang township and Litun township. Obviously, the comprehensive assessment model had preferable operability and practicability, it not only combined subjective evaluation with objective appraisal, but also qualitative with quantitative study, and fully considered of each assessment factor. Therefore, AHP method is scientific and reasonable and suit to be used to evaluate the level of planting elements assessment.

Introduction

Planting was the foundation of agriculture and a special place in agriculture, which only related to the overall situation of national food security. It was also an important income source of the farmers, its value was more than 50% of the total agricultural value. A total of 66 articles were retrieved in the Chinese journal of literature since 2011 as a summary of the key word "planting evaluation". Retrieval results showed that Gaojun "the high military cropping systems in the suburbs of Beijing ecological security assessment and technical countermeasures -take the case of Shunyi District, Beijing", Shi Chenyang, etc. "The Study of the Technology Path of the Efficient Using Water of the Piedmont of Mt. Taihang Mountain in Hebei Province", Zheng Yalian "Cultivated Land Fertility Evaluation and Planting Industry Layout in Tongzhou District of Beijing" and Liu Tian-sen "research on the application of comparative advantage theory in Chinese regional farming" were retrieved in database. The less literature study and the weak quantitative study related to planting evaluation were presented in the retrieval contents. It was necessary to establish a set of scientific indicator system on township/town scale for the comprehensive assessment of planting elements. Among evaluation methods, the analytic hierarchy process (AHP) can use opinions of experts to construct the judgment matrix, so it was meaningful. So the objective of the study was develop the quantitative evaluation of planting elements on town/township scale in Yucheng city, and the article regarded the rural areas and agriculture information as the evaluation indicator, a set of reasonable indicator system of planting assessment was proposed on township/town scale, and the system provides a visual way for users to do all the works of AHP, so the study presented academic significance [START_REF] Gaojun | Assessment and Technical Countermeasures of Ecological Safety of Cropping System in Suburban Region in Beijing--A Case Study in Shunyi County[END_REF][START_REF] Shi | The Study of the Technology Path of the Efficient Using Water of the Piedmont of Mt. Taihang Shan in Hebei Province[END_REF][START_REF] Yalian | Cultivated Land Fertility Evaluation and Planting Industry Layout in Tongzhou District of Beijing[END_REF][START_REF] Liu Tian-Sen | Research on the Appliation of Comparative Advantage Theory in Chinese Regional Farming[END_REF] . In some correlated research, the quantitative studies were developed by fuzzy method and other methods as the above research,but the planting elements assessment had the less study from the correlation literatures and the study did not involve in the country level, and AHP method was scientific and reasonable and suit to be used to evaluate the level of planting elements assessment, so the method was selected in the article.

2

Material and Methodology

Analytical hierarchy process

Analytical Hierarchy Process (AHP) was developed by A.L.Saaty. AHP method was a multi-objective decision analytical method that combines qualitative with quantitative analysis and also a kind of optimization techniques, so it could be used to calculate the weight of each indicator. The essence of the process was decomposition of a complex problem into a hierarchy with goal (objective) at the top of the hierarchy, criterions and sub-criterions at levels and sub-levels of the hierarchy, decision alternatives at the bottom of the hierarchy. Elements at given hierarchy level were compared in pairs to assess their relative preference with respect to each of the elements at the next higher level. The verbal terms of the Saaty's fundamental scale of 1-9 was used to assess the intensity of preference between two elements. The number of 1 indicates equal importance, 3 moderately more, 5 strongly more, 7 very strongly and 9 extremely more importance. The numbers of 2, 4, 6, and 8 were allotted to indicate compromise values of importance. The method computed and aggregated their eigenvectors until the composite final vector of weight coefficients for alternatives was obtained. The entries of final weight coefficients vector reflected the relative importance (value) of each alternative with respect to the goal stated at the top of hierarchy. During the AHP process, the steps were as follows: Form assessment indicator set. Establish stepped hierarchical construction. Ascertain the weight of the indices. Construct comparison judgment matrix and monolayer weights order. Consistency test and comprehensive assessment of AHP [START_REF] Liu Tian-Sen | Research on the Appliation of Comparative Advantage Theory in Chinese Regional Farming[END_REF] .

Construction of indicator system of planting elements assessment

Construction of indicator system was the premise of planting elements evaluation, so we constructed the indicator system according to the following principles: (1) Comprehension: The factor must reflect each side of the appraised object, study its connotation and extension deeply in the process of construction, making every effort to fully and actually manifest it. (2) Operability: Weight of each indicator should be determined and the evaluation method stresses on availability of indicator data. (3) Guidance:Prospective and tendency factors should be introduced to guide the direction of planting development. (4) Connection: The indicator system should link up with regional planting index system and reflect the development characteristic of planting itself. ( 5) Comparability: The general targets should be introduce in the system indicator [START_REF] Jing | Research on assessment method for rural information level based on AHP[END_REF] .

We selected 8 indicators from the above principles to develop the comprehensive assessment of planting elements, the detailed contents referred to Table 1. In the indicator system, agriculture information indicator was introduced firstly in information and energy sub-system in the AHP model. The core content of planting elements assessment included 3 mutually and closely contacted planes: resource subsystem, information and energy sub-system and social-economic sub-system. There was no doubt that AHP provided a scientific measure for analysis and decision making. Juzhen township, Fangsi town, Shizhong subdistrict office, Xinzhai town,Xindian town,Zhangzhuang town,Liangjia town,Anren town,Lunzhen town,Shiliwang township and Litun township, the weight above 11 townships/towns is 0.205, 0.135, 0.104, 0.087, 0.086, 0.084, 0.078, 0.068, 0.062, 0.060, 0.032 respectively, the weight value indicated that the planting elements dominance of 11 towns/townships is 0.205, 0.135, 0.104, 0.087, 0.086, 0.084, 0.078, 0.068, 0.062, 0.060 and 0.032, respectively.

Conclusions and Discussion

In a word, we drew conclusions that a set of reasonable indicator system in planting elements assessment was proposed on the township/town scale in this paper, it was suitable for processing by computers and was worth promoting. Furthermore, using AHP model, the paper constructed the hierarchical structure model of the planting elements assessment and calculated the factor weight of resource sub-system, information and energy sub-system and social-economic sub-system. Based on it, the planting elements dominance from the comprehensive assessment was Juzhen township, Fangsi town, Shizhong subdistrict office, Xinzhai town, Xindian town, Zhangzhuang town, Liangjia town, Anren town, Lunzhen town, Shiliwang township and Litun township. Obviously, the comprehensive assessment model of planting elements had preferable operability and practicability. It not only combined subjective evaluation with objective appraisal, but also qualitative with quantitative study, and fully considered of each assessment factor in system evaluation. Therefore, AHP method was scientific and reasonable to be used to evaluate the level of planting elements on country level.

Table 1 .

 1 Contents of Indicator System based on AHP

		Indicator name	Indicator content and significance
	B 1 :Reso urce sub-system	C1:Fertilizer consumption per sown area C2:Pesticide consumption per sown area C3:Farmland plastic Film	Fertilizer consumption/crop sown area Pesticide consumption/ crop sown area Farmland plastic film consumption/ crop sown
		consumption per sown area	area
	B 2 :Infor
	mation
	and
	energy
	sub-
	system

Table 5 .

 5 The Total order Weight Value of Hierarchy in AHP of 11 town/townships

	Target Layer	Criterion Layer	Weight	Measure Layer	Object Layer	Total weight	Total
								Layer
		Resource	sub-	0.694	Fertilizer consumption per sown	Shiliwang township	0.060	10
		system			area	Anren town	0.068	8
					Pesticide consumption per sown	Lunzhen town	0.062	9
					area
	planting				Farmland Plastic Film consumption
	elements				per sown area
	assessment	Information and	0.132	Agriculture information Level	Juzhen township	0.205	1
		energy	sub-		Total Agricultural Machinery	Litun township	0.032	11
		system			Power and energy information
		Social-Economic	0.174	effective irrigation capacity	Fangsi town	0.135	2
		sub-system			output ratio of planting industry	Xinzhai town	0.087	4
					Agricultural scale management	Xindian town	0.086	5
						Zhangzhuang town	0.084	6
						Liangjia town	0.078	7
						Shizhong subdistrict	0.104	3
						office

C4:Agriculture information status

Synthesis weight for infrastructure information of agriculture and production information of agriculture C5:Total agricultural machinery power and energy information The weight included the total agricultural machinery power, main energy and power consumption information Selection principle of indicator AHP model, combined with the indicator system of planting elements Assessment in Yucheng city, hierarchy construction schematic diagram was shown in Fig. 1. The graded hierarchical construction model of planting elements assessment included four layers on regional scale, target layer, rule layer, measure layer and object layer.

Where, the parameter meaning of B1,B2,B3 C1,C2,C3,C4,C5,C6,C7,C8 referred to Table .1, S1, S2, S3, S4, S 5, S 6, S 7, S 8, S 9, S10 and S11 respond to the Shiliwang township, Anren town, Lunzhen town, Juzhen township, Litun township, Fangsi town, Xinzhai town, Xindian town, Zhangzhuang town, Liangjia town and Shizhong subdistrict office in Yucheng city.

Results and Analysis

By pairwise comparing elements of the same layer in accordance with certain upper factor, each element of the judgment matrix was able to be defined. The relative importance of each element followed 1-9 proportion evaluation scale. Several judgment matrixes can be established based on the scores that experts provided. The importance that each element of No.(k+1) layer relative to No.k layer was ordered according to the judgment matrix. The weights of judgment matrix of AHP model were shown in Table 2. and Table 3.

Table 3 Comparison Judgment Matrix of Eigen Vector

To ensure the monolayer weights order was correct, the judgment matrix should be dealt with consistency test. Consistency should be tested as follows: Computing consistency index CI (CI = lmax -n/n-1), where: lmax was the eigenvalue of maximum, n represents for the number of the order of judgement matrix. If CR<0.1, the consistency of the judgement matrix can be satisfied and so the order weights accepted.

Calculating consistency ratio CR:CR= CI/RI, the final results of AHP were validated by the random consistency ratio CR. If CR<0.1, the results can meet the requirements. The values of  max, CI and the values of CR are shown in the Table 4, the values of CR are all less than 0.1, so the consistency test of the parameters was passed. Based on the assessment factor matrix and the monolayer weights matrix, the value of comprehensive assessment of the planting elements can be determined, the validation parameters (C.I.= 0.075 ,R.I=1.52,C.R.= 0.049<0.1) were passed in the model, the results were shown in the Table 5.