Go to the main menu
Skip to content
Go to bottom
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 18, Issue 4 - Dec 1993
Volume 18, Issue 3 - Sep 1993
Volume 18, Issue 2 - Jun 1993
Volume 18, Issue 1 - Mar 1993
Selecting the target year
Evaluation of Ride Vibration of Agricultural Tractors(III) -Measurement and Evaluation of Ride Vibrations-
Chung, S.S. ; Kim, K.U. ; Moon, G.S. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 191~198
Vertical and horizontal ride vibrations of the selected agricultural tractors were measured and evaluated with respect to the ISO 2631 'guide for the evaluation of human exposure to whole body vibration'. Evaluation showed that at the normal transportation speeds of 1.4~20km/h on both the concret and ground surfaces tractor drivers were exposed to the vibrations whose magnitudes exceed the 8 hour fatigue decreased proficiency boundary in the frequency ranges of 2~16Hz in vertical and 1~2Hz in horizontal directions. Considering that tractor operation becomes as one of the specialized job for the future farming in Korea, measures must be made to protect the drivers against harmful ride vibrations of agricultural tractors.
Tractor Implement Attitude Control System Using Microcomputer
Yoo, S.N. ; Suh, S.R. ; Kim, D.J. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 199~208
This study was attempted to develop the eletronic-hydraulic hitch system for controlling the attitude of tractor implements and to investigate control performance of the system through experiments. Main components of the system developed in this study were reference inputs panel, inclination angle detecter, electronic controller consisted of IBM-AT PC and interfaces, electro-hydraulic directional valves and other hydraulic components and three-point hitch linkage. Experiments were carried out to investigate the response of the system to the step and sine inputs. The effects of hydraulic flow rate and dead band on control performance were analized. Attitude of the implement was controlled within 2.4-5.1 degrees to the setting attitude when the hydraulic flow rate was in the range of
. And implement was controlled without rapid amplitude attenuation and phase angle change in the frequency range of 0.02-0.2Hz when the hydraulic flow rate was in the range of
. Control performance of the system can be expected to be improved if the inclination angle detecter show rapid and stable output as the implement moves.
Draft Prediction of Bulldozer Blade by Model Tests
Lee, K.S. ; Roh, S.C. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 209~219
A series of soil bin experiment was carried out on sand to investigate if true model theory is applicable to blade-soil system and finally to find mathematical relationship between the dimensionless terms which contain the blade-soil parameters. The following conclusions were derived from the study. 1. It was proved that the draft of the prototype blade can be predicted without distortion by those of model blades with the length scale of 1.2, 2 and 2.4. 2. For the sand, bulk density was found to be a good measure of soil physical properties which are pertinent to predict the draft of the blade-soil system. 3. The mathematical relationship between
are as follows ;
Similitude Study of Performance of Lugged Wheel on Soft Soils
Lee, K.S. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 220~229
A dimensional analysis was carried out to investigate if model agricultural radial tire can predict the tractive performance of prototype tires. Experimental data was analyzed to prove the results of dimensional analysis. The results was summerized as follows ; 1. When the model and prototype tires are tested under the same soil conditions, inflation pressure, slip and dynamic load, traction coefficient ratio between two tires depend on the geometry of two tires. 2. According to the regression analysis of the experimental data, traction equation parameters of the prototype tires can be predicted from the that of model tire 3. Predicted traction coefficient of prototype tire, calculated from the traction equation paramters, showed good correlation with that of experimental results. Thus it was possible to predict net and gross traction of prototype tire from the model traction equation parameters.
Developement of A Computer Simulation Program for the Design of High Speed Transplanting Mechanism(II) -Force Analysis-
Park, H.J. ; Kim, K.U. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 230~238
The parte(I) of this paper deals with the motion analysis of a gear type high speed planting mechanism of rice transplanters. Following that this part(II) contains force analysis of the mechanism. Forces and moments acting on the mechanism were determined analytically and computer coded for the simulation of them on any IBM PC compatiable machines. The simulation program developed in this study can be used as a design tool and also for a sensitivity analysis.
Effect of Rubber Damper of Flywheel on the Vibration of Diesel Engine
Myung, B.S. ; Kim, S.R. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 239~251
Data acquisition system and computer program developed in this study could be well used in engine vibration analysis. The system and program developed were also operated to be able to control measuring interval, number of channels, number of data. The flywheel was specially studied to provide the proper weight with rubber damper for the engine design at low level of vibration. This study was conducted to obtain basic data which affect the engine vibration. The experiment of this study was performed on original weight flywheel, weight-reduced flywheel, weight-reduced and rubber-coated flywheel, weight-reduced and damper-attached flywheel. Avarage of peak value, maximum vibration, power spectrum density based on FFT analysis are major factors of this experiment. Results were obtained as follows : 1. When rubber was inserted in the flywheel rim of which weight was reduced from 32.2kgf to 24.4 kgf, maximum vibration of the engine was decreased 48.3% at X axis, 35.5% at Y axis and 34.6% at Z axis in comparison with the flywheel of original weight. 2. When the flywheel of rubber damper was compared with the original flywheel, the average of absolute vibration for rubber damped flywheel was decreased at X, Y, Z axis and especially its decreasing rate was so high at X-axis comparing with the other flywheel, which implied that rubber damper was very useful to reducing the vibration of the engine at X axis. 3. Hysteresis losses of X, Y, Z axis were greatly decreased in the flywheel with rubber damper on rim. 4. Damped oscillation effect on X and Y axis vibration above average peak vibration by the flywheel of rubber damper on rim was larger than those by the other flywheels. 5. Power spectrums of vibration at real and imaginery part were bi-mode type. The vibration frequency of rubber dampered flywheel which weight is decreased was slightly increased as compared with original flywheel.
Development of Nondestructive Moisture Sensor for Agricultural Products Using Hydrogen NMR : Feasibility Experiments
Cho, S.I. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 252~261
Nuclear magnetic resonance(NMR) was used to study a feasibility test for the possibility to develop a moisture sensor applicable for agricultural products such as raw and powdered grain. Samples of wheat flour and brown rice were tested with a 200MHz hydrogen NMR. The samples were loaded into 5mm NMR glass tubes and
pulses were supplied to get resonance signals. Hydrogen spectrum intensities of the samples were compared to moisture content measured by a drying oven method. High linear correlations were obtained between the hydrogen spectrum intensity and moisture content. Therefore, moisure contents of agricultural products could be measured nondestructively utilizing the NMR principle. A low-cost design concept of the moisture sensor with the NMR principle was proposed for a practical use.
Stress Relaxation Properties of Cucumber under Bending Moment
Song, C.H. ; Kim, M.S. ; Park, J.M. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 262~269
Stress relaxation behaviors of the cucumber under bending moment were tested with UTM at three levels of loading rate and initial deflection ratio. Sample cucumber was selected from three cultivars of cucumber, Cheongjangmadi, Baekdadagi, and Gyeousalicheongjang, because these cultivars are the most popular grown cultivars in Korea. When the bending moment was applied to the cucumber sample, the effective span between simple supports was held a constant value of 116mm with consideration of the selected sample length. The objectives of this study were to develop the rheological models such as linear and nonlinear models of the stress relaxation for the cucumber samples, and to investigate the effects of loading rate and initial deflection ratio on the stress relaxation behavior of the cucumber. The results of this study may be summarized as follows : 1. Stress relaxation behavior of the cucumber could be well described by the generalized Maxwell model for each level of deflection ratio. But the stress relaxation behavior of the sample was found to be initial deflection ratio and time dependent, and it was represented the nonlinear viscoelastic model as a function of initial deflection ratio and time. 2. Stress relaxation behavior of the cucumber samples was very highly affected by the loading rate and the initial deflection ratio. The more loading rate and initial deflection ratio resulted in the more initial bending stress and after stress relaxation progressed more rapidly. 3. At the same test conditions, it was found that the stress relaxation rate of Cheongjangmadi was faster than that of other cultivars.
Effect of Opening Ratio of Red Pepper Surface on Drying
Cho, Y.J. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 270~274
Many researches have been performed to shorten drying time and cost of red pepper in Korea. Nevertheless, an effective drying method for red pepper is not developed yet. This study was conducted to analyze the effect of opening ratio of red pepper's surface on drying for development of an effective drying method. The drying method with punching treatment is expected to be effectively utilized for shortening drying time and improving quality of red pepper.
Velocity Profiles and Entrance Length of Transitional Oscillatory Flows in the Entrance Region of a Square Duct
Choi, J.H. ; Choi, B.M. ; Yoo, Y.T. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 275~287
The flow characteristics of the transitional oscillatory flows are investigated analytically and experimentally in the entrance region of a square duct. The systems of conservation equations are analytically solved by linearizing the non-linear convective terms for the developing transitional oscillatory flows in a square duct. The analytical solutions are obtained in the form of infinite series for the velocity profiles. The experimental study for the air flow in a square duct is carried out to measure the velocity profiles and waveforms by using a hot-wire anemometer with the data acquisition and processing systems. The theoretical and experimental results provide the major characteristics of the developing transitional oscillatory flows, such as velocity profiles, velocity waveforms, and entrance length. The velocity profiles in the decelerating phase are larger than those in the accelerating phase for the developing transitional oscillatory flows. The correlations of the entrance length of the transitional oscillatory flows in a square duct are found to be
, where K is 1.23 of an experimental constant.
Color Grading of Hardwood Dimension Parts with Color Computer Vision
Yoo, S.N. ; Krutz, Gary W. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 288~295
Control Methods and Drive Circuitries for A Control Stepping Motor(II)
Lee, D.W. ;
Journal of Biosystems Engineering, volume 18, issue 3, 1993, Pages 296~310