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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Biosystems Engineering
Journal Basic Information
Journal DOI :
Korean Society for Agricultural Machinery
Editor in Chief :
Volume & Issues
Volume 27, Issue 6 - Dec 2002
Volume 27, Issue 5 - Oct 2002
Volume 27, Issue 4 - Aug 2002
Volume 27, Issue 3 - Jun 2002
Volume 27, Issue 2 - Apr 2002
Volume 27, Issue 1 - Feb 2002
Selecting the target year
Development of a Hydraulic Level Control System for High-speed Rice Transplanting Machines
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 79~88
DOI : 10.5307/JBE.2002.27.2.079
This study was conducted to develop system for high speed rice transplanting machines. The control system includes a sensor detecting the tilt angle of the seedling bed, a micro-controller and a hydraulic system consisting of a double acting cylinder, a four-way three-position solenoid valve, a relief valve and a hydraulic pump. The levelling system shared the pump with the existing steering control, resulting in a tandem center circuit for the steering and levelling control systems. Using the input signal from the sensor, the micro-controller determined and generated the output signal to control the cylinder through the solenoid valve to keep the seedling bed always parallel to the water surface regardless of soil unevenness during the transplanting operations. Both an ON/OFF and a PWM control schemes were tested. When the flow rate was more than 1 ι/min in the ON/OFF control, the system showed unstable rolling. However, in the PWM control, the system worked stably although the flow rate was more than 1 ι/min. The PWM control showed a better performance when a large difference between the angle and the dead band of the control system occurred. The characteristics of tile system response to given tilt angles were predicted by a computer simulation. Both the ON/OFF and the PWM control systems worked well providing that the operating and waiting times were properly adjusted.
Development of Vegetable Soybeans Thresher (I) - Physical properties and threshing characteristics of vegetable soybeans -
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 89~96
DOI : 10.5307/JBE.2002.27.2.089
The trend of consumption of vegetable soybeans is increasing because they are recognized as the clean vegetable. The works requiring the most intensive labor are threshing and seperation ones, and they form about 80% of total labour for vegetable soybeans production. It is necessary to develop the vegetable soybeans-thresher for the sake of cost down of vegetable soybeans production. The purpose of this study is to acquire the basic informations to design of the vegetable soybeans-thresher. We make the experimental system which control the speed of threshing cylinder and the teeth gap and investigate the detachment forces. The result are as follows ; The ratio of un-threshed soybeans-pod to stem after threshing work is decreasing as the threshing cylinder speed increases: 0.0% and 2.8% at 55m/s and 18m/s of threshing cylinder speed respectively. Also the ratio of un-threshed soybeans-pod to stem is shown as 2.0% below in the condition of 64~160mm of teeth gap and over 28m/s of threshing cylinder speed. The damaged pod ratio of detached soybeans after threshing work is decreasing as the threshing cylinder speed increases: 4.8% and 1.3% at 55m/s and 18m/s of threshing cylinder speed respectively. The minimum damaged pod ratio of detached soybeans are shown as 1.0%, 1.5% and 1.9% at 18m/s, 28m/s and 37m/s of threshing cylinder speed respectively. The average detachment forces of pods are shown as 1.5kg
for 3 grains, 1.2kg
for 2 grains and 0.8kg
for 1 grain respectively. The maximum detachment force of pod is shown as 2.7kg
for 3 grains. grains.
Development of Automatic Vegetables Binding Machine (I) - Research scope and materials feeding mechanism -
Kang, C. H. ; Han, K. S. ; Yun, J. H. ; Son, J. R. ; Kim, Y. J. ;
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 97~106
DOI : 10.5307/JBE.2002.27.2.097
An Analysis of Farmers' Behavior on Dealing with Secondhand Agricultural Machine
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 107~116
DOI : 10.5307/JBE.2002.27.2.107
This study was designed to analyze farmers' behavior on dealing with secondhand agricultural machinery and to device proper measures for promoting utilization of secondhand agricultural machinery. This objective was accomplished by using data which were analyzed, collected through questionnaires from 35 farmers on dealing with secondhand agricultural machinery. The main, realistic measures for promoting utilization of secondhand agricultural machinery, based on farmers' behavior, are as fellows: First, to make and offer a criteria fer evaluating the optimal price of secondhand agricultural machinery, which should be a effective measure for promoting farmers' dealing with them. Second. to establish a store to exhibit and sell secondhand agricultural machinery. This is the most important way to promote dealing with them. In the process of political supporting to establish the store, the equality of opportunity should be adopted to every organization want to deal secondhand agricultural machinery. Third, to strengthen financial supports for buying secondhand agricultural machinery and to assure A/S system.
Compensation of Surface Temperature Effect in Determination of Sugar Content of Shingo Pears using NIR
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 117~124
DOI : 10.5307/JBE.2002.27.2.117
This research was conducted to develop a method to remove the effect of surface temperature of Shingo pears for sugar content measurement. Sugar content was measured by a near-infrared spectrum analysis technique. Reflected spectrum and sugar content of a pear were used for developing regression models. For the model development, reflected spectrums having wavelengths in the range of 654 to 1,052nm were used. To remove the effect of surface temperature, special sample preparation techniques and partial least square (PLS) regression models were proposed and tested. 71 Shingo pears stored in a cold storage, which had 2
inside temperature, were taken out and left in a room temperature for a while. Temperature and reflected spectrum of each pear was measured. To increase the temperature distribution of samples, temperature and reflected spectrum of each pear was measured four times with one hour twenty minutes interval. During the experiment, temperature of pears increased up to 17
. The total number of measured spectrum was 284. Three groups of spectrum data were formed according to temperature distribution. First group had surface temperature of 14
and total number of 51. Second group consisted of the first and the fourth experiment data which contained the minimum and the maximum temperatures. Third group consisted of 155 data with normal temperature-distribution. The rest data set were used for model evaluation. Results shelved that PLS model I, which was developed by using the first data group, was inadequate for measuring sugar content of pears which had different surface temperatures from 14
. After temperature compensation, sugar content predictions became close to the measured values. Since using many data which had wide range of surface temperatures, PLS model II and III were able to predict sugar content of pears without additional temperature compensation. PLS model IV, which included the surface temperatures as an independent variable. showed slightly improved performance(R
=0.73). Performance of the model could be enhanced by using samples with more wide range of temperatures and sugar contents.
Milled Rice Recovery Rate of Paddy with Various Moisture Contents
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 125~132
DOI : 10.5307/JBE.2002.27.2.125
In order to investigate the optimum moisture content of paddy for milling process, a series of tests were conducted by examining the recovery rate and whiteness of milled rice in relation with the various moisture content. Hwabong-byeo and Dongjin-byeo varieties which were major paddies cultivated in Korea were used for the experiment. The test was performed with small experimental milling machines. In order to minimize the unexpected factors, environment conditions were kept in constant during the experiment. As a result, the recovery rate of milled rice were varied as the changes in milling time and degree of whiteness. However, the recovery rate of milled rice increases as its moisture content increases untill a certain point of moisture content and decreases slowly afterward. This certain point can be called optimum moisture content for rice milling. Also, it has a different value depending on the variety. In this experiment, optimum moisture content of Hwabong-byeo and Dongjin-byeo were considered around 14.8% and 15.3%, respectively. It is not sure that these optimum moisture contents for the two varieties would assume the same values irrespective of harvest year and place. However, it could be concluded that the optimum moisture content for rice milling is around 15%(w.b.) for Hwabong-byeo and 15.5%(w.b.) for Dongjin-byeo, respectively.
A Fundamental Study on Detection of Weeds in Paddy Field using Spectrophotometric Analysis
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 133~142
DOI : 10.5307/JBE.2002.27.2.133
This is a fundamental study to develop a sensor to detect weeds in paddy field using machine vision adopted spectralphotometric technique in order to use the sensor to spread herbicide selectively. A set of spectral reflectance data was collected from dry and wet soil and leaves of rice and 6 kinds of weed to select desirable wavelengths to classify soil, rice and weeds. Stepwise variable selection method of discriminant analysis was applied to the data set and wavelengths of 680 and 802 m were selected to distinguish plants (including rice and weeds) from dry and wet soil, respectively. And wavelengths of 580 and 680 nm were selected to classify rice and weeds by the same method. Validity of the wavelengths to distinguish the plants from soil was tested by cross-validation test with built discriminant function to prove that all of soil and plants were classified correctly without any failure. Validity of the wavelengths for classification of rice and weeds was tested by the same method and the test resulted that 98% of rice and 83% of weeds were classified correctly. Feasibility of CCD color camera to detect weeds in paddy field was tested with the spectral reflectance data by the same statistical method as above. Central wavelengths of RGB frame of color camera were tried as tile effective wavelengths to distingush plants from soil and weeds from plants. The trial resulted that 100% and 94% of plants in dry soil and wet soil, respectively, were classified correctly by the central wavelength or R frame only, and 95% of rice and 85% of weeds were classified correctly by the central wavelengths of RGB frames. As a result, it was concluded that CCD color camera has good potential to be used to detect weeds in paddy field.
Development of Real-time Precision Spraying System Using Machine Vision and DGPS
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 143~150
DOI : 10.5307/JBE.2002.27.2.143
Several researches for site-specific weed control have tried to increase accuracy of weed detection with machine vision technique. However, there is a problem which needs substantial time to perform site-specific spraying. Therefore, new technology for real-time precision spraying system is needed. This research was executed to develope the new technology to estimate weed density and size in real time, and to conduct a real-time site-specific spraying. It would effectively reduce herbicide amounts applied for a crop field. The real-time precision spraying system consisted of a Differential Global Positioning System (DGPS) with an error of 2 cm, a machine vision system, a geomagnetic sensor for correction of view point of CCD camera and an automatic sprayer with separately controlled nozzle. The weed density was calculated with comparison between position information and a pre-designed electronic map. The position information was obtained in real time using the DGPS and the machine vision. The electronic map contained a position database of crops automatically constructed when seeding. The developed system was tested on an experimental field of Seoul National University. Success rate of the spraying was about 61%.
Development of Computer Vision System for Individual Recognition and Feature Information of Cow (I) - Individual recognition using the speckle pattern of cow -
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 151~160
DOI : 10.5307/JBE.2002.27.2.151
Cow image processing technique would be useful not only for recognizing an individual but also for establishing the image database and analyzing the shape of cows. A cow (Holstein) has usually the unique speckle pattern. In this study, the individual recognition of cow was carried out using the speckle pattern and the content-based image retrieval technique. Sixty cow images of 16 heads were captured under outdoor illumination, which were complicated images due to shadow, obstacles and walking posture of cow. Sixteen images were selected as the reference image for each cow and 44 query images were used for evaluating the efficiency of individual recognition by matching to each reference image. Run-lengths and positions of runs across speckle area were calculated from 40 horizontal line profiles for ROI (region of interest) in a cow body image after 3 passes of 5
5 median filtering. A similarity measure for recognizing cow individuals was calculated using Euclidean distance of normalized G-frame histogram (GH). normalized speckle run-length (BRL), normalized x and y positions (BRX, BRY) of speckle runs. This study evaluated the efficiency of individual recognition of cow using Recall(Success rate) and AVRR(Average rank of relevant images). Success rate of individual recognition was 100% when GH, BRL, BRX and BRY were used as image query indices. It was concluded that the histogram as global property and the information of speckle runs as local properties were good image features for individual recognition and the developed system of individual recognition was reliable.
Construction of a Spatial Database for Realizing Precision Farming
Journal of Biosystems Engineering, volume 27, issue 2, 2002, Pages 161~172
DOI : 10.5307/JBE.2002.27.2.161
Database as a supporting system for decision-making is one of essential parts for realizing precision farming. Application models on constructing a database for precision farming, including collection of spatial and attribute data, were suggested using a GPS, DXF files, AutoCAD, a Java application program and PostgreSQL DBMS in this study. The constructed spatial database based on the schema design of spatial and attribute data table was evaluated as a supporting system for decision-making by a simulation of a virtual variable-rate chemical applicator. The applicator could extract the values of soil property at its consecutive location in the tested field in communication with the constructed database, and prescribe the corresponding variable-rate of chemicals. The results of the study suggested the possibility that the constructed database can function a supporting system for decision-making for precision farming.