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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
Analysis and Isolation of Walking-type Cultivator Vibration Transmitted to Operator′s Hands
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 273~282
DOI : 10.5307/JBE.2002.27.4.273
This study was intended to measure and analyze hand-transmitted vibrations from cultivator in idle and operation modes for three different types of field works. Based on this analysis a time for the white finger syndrome to appear on 10% of the operators was estimated assuming that their daily exposure is 3 hours. The 4 methods to reduce the hand vibration were also proposed and compared with each other. The results of the study were summarized as follows : The highest vibration level was recorded during trenching operation, resulting in a total average vibration of 11.5 m/s
. Followings were 7.6 m/s
during rotary tillage and 7.0 m/s
for weeding. When exposed to these levels of vibrations three hours a day, the white finger syndrome is likely to appear in 4 years for trenching, 6.2 years for rotary tillage and 6.8 years for weeding operations. Isolation of hand vibration performed by a rubber pad, anti-vibration gloves, a handle anti-vibration device and engine mounts were respectively 15.7%, 16.5%. 26.1% and 27.0%, resulting in most effective methods of the handle anti-vibration device and engine mounts. A better performance of about 33.9% was achieved when both the handle anti-vibration device and engine mounts were used.
Physical Properties or Jujube (Zizyphus jujuba miller) and Jujube Branches
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 283~292
DOI : 10.5307/JBE.2002.27.4.283
Mechanical and physical properties of various parts of jujube (Zizyphus jojoba Miller) such as fruits, leaves, secondary branches, and leafy stems were measured and analyzed. The physical dimensions of the fruits were measured using a digital caliper, and the detachment force of the fruit and leafy stems was measured using a force gauge. The physical characteristics of the secondary branches such as the modulus of elasticity and the torsional rigidity were tested using a universal testing machine (UTM). The physical characteristics of leafy stems such as length and weight were also measured using a digital caliper and a digital scale, respectively. The detachment force of leafy stems and the area of the leaf also measured. The terminal velocities of the jujube fruits, leaves, and leafy stems were measured using a custom made terminal velocity experiment system. Diameter of the major and minor axis of the jujube fruit, weight of the fruit, and detachment force of the fruit stem was average of 32.02 mm, 23.92 mm. 10.0
6/ ㎥, 8.99 g, and 5.43 N. respectively. The detachment forces of the jujube fruits increased and the force-to-weight ratio of the jujube fruits decreased as the weight of the jujube fruits increased. The modulus of elasticity of the secondary branches of the jujube was average of 7.01
8/ N/㎡ and decreased as diameter of the secondary branches increased. The average torsional rigidity of the secondary jujube branches was 5.2
-/ N/㎡, and the torsional rigidity decreased as the secondary branch diameter increased. The distribution of the torsional rigidity data associated with the diameter of the branches, however. widely scattered and it was difficult to find any relationship between the diameter of the branches and the torsional rigidity of tile branches. The weight of the leafy stems, number of loaves attached to the leafy stems, diameter of the stem side of the leafy stems, diameter of the leafy stem end was average or 0.7 g, 6.6 ea, 12.2 cm, 4.5 mm, and 2.7 mm, respectively. The major and minor axis of the .jujube loaves, area of leaves, weight of the leaves. and detachment force of the leaves was average of 5.7 cm, 3.3 cm, 12.98 cm
, 0.20 g, and 4.39 N, respectively. The terminal velocity of the .jujube fruits increased as the weight of the fruits increased. The terminal velocity of the leafy stems, however, did not show a relationship with the weight of the leafy stems and the number of leaves attached to the leafy stem. The terminal velocity, however, slightly increased as the length of the leafy stems increased.
The Acoustic Vibration Properties for Chicken Eggs
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 293~300
DOI : 10.5307/JBE.2002.27.4.293
Surface crack detection is an important aspect in the quality control process of egg markets. The acoustic vibration of an egg could be used as a critical factor in evaluating the eggshell quality. The mode shape indicates the egg vibration behavior at different locations with respect to the input impulse and provides important information for the optimum sensor location to obtain the desired acoustic measurements. Theoretical analysis and experimental measurements were conducted to determine the acoustic vibration modes in eggs. The resonant fiequencies of the first and second resonance mode of intact eggs were found to be distributed between 2kHz and 7kHz range. The measured mode shapes of an egg were similar to theoretical shapes of homogeneous, elastic spheres. An elliptical deformation at the equator ring of the egg was observed. The frequency peak of this mode was dominantly present in the frequency spectrum of an intact egg impacted at its sharp position. The mode shapes related to the first resonant frequency of an egg shelved that the optimum location for the measuring sensor was the 180 degrees position. A optimum location for the egg support was found to be the 90 degrees position having the smallest vibration magnitude.
Development of An Onion Peeler (I) - Root cutting equiment -
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 301~310
DOI : 10.5307/JBE.2002.27.4.301
With a purpose to manufacture an onion peeler, the root cutting equipment of the onion could be attached to a prototype onion peeler was developed. Before the experiment, the distribution of the dimensions of the Korean native onion were measured. And some types of the blades to cut and remove the root of the onion were designed and such characteristics as feasible revolution, conveying speed, and power requirement were investigated. From the result of the test, the selected one among the various cutters was the wing type blade with the round blade to cut out the root and with the vertical blade to cut a circular line. The optimum operating conditions of the wing type blade were revealed the revolution with no load was at 630 rpm, and the conveying speed was 0.08 m/s. Under these conditions, the maximum torque was 5.25 kg·m and the power requirement was 33 W, respectively.
Development of An Onion Peeler ( II ) - Air injection type peeling equipment -
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 311~316
DOI : 10.5307/JBE.2002.27.4.311
This study was carried out to investigate the optimum operating conditions of the air injection type onion peeling device which could be attached to a prototype onion peeler. An onion, stem and root was cut and some vertical line was dug in 1 mm depth on the skin, was put on the two parallel rollers. The diameters of the rollers were 105 mm and the ratio of peripheral velocity was 3:2, and moved by a geared motor. Air from the nozzle with high pressure and velocity was jetted to the rotating onion on the revolving rollers, and then the skin of the onion was stripped. On the test, the rolling characteristics of the experimental materials were measured. The effective peeling conditions were, the number of digging line on the skin of the onion was 4, and the air jet pressure was above 392.3 kPa(4.0 kg/
) when the peripheral velocity was at 2.4 m/s. On these conditions, time requirement to peel an onion was less than 2 sec.
Improvement of the Efficiency of a Twin-fluid Nozzle using Ultrasonic Vibration
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 317~326
DOI : 10.5307/JBE.2002.27.4.317
Characteristics of a twin-fluid spray with ultrasonic vibration were examined in order to obtain a high efficiency of cold-fog spray of the automatic pest control machine which has been widely used in protected horticulture recently. An electrostrictive vibrator of PZT BLT and a magnetostrictive
-type vibrator were used applied as the ultrasonic transducers with a frequency of 28 kHz. All experiments were conducted in 4 methods of spray ; a conventional spray method without ultrasonic forcing, an indirect vibration method with ultrasonic forcing, an improving-quality method by ultrasonic forced within liquid, and a combined-use method with both of the indirect vibration method and the improving quality method. It was found that the ultrasonic energy increased the atomization efficiency of spray droplets about 10% and especially much more in the case of the combined-use method.
Development of Solar Powered Water Pump - Energy conversion test and performance analysis -
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 327~334
DOI : 10.5307/JBE.2002.27.4.327
In this study, energy conversion from thermal energy to mechanical power by using n-pentane was tested and exergy variation, cycle number, water quantity pumped and thermal efficiency were analyzed. The energy conversion was done and the water head could be ten meters on the experimental conditions. The operating temperature range of cycle was recommended to be around the liquid-vapour saturation temperature of the working fluid on the viewpoint of the maximum work. The cycle diagram was analyzed by the exergy analysis. For the constant water head, the cycle number was decreased and the water quantity per day was increased and thermal efficiency become higher when the water quantity per cycle become increasing. For the constant pumping water quantity per cycle, cycle number and the water quantity per day was decreased and the thermal efficiency become higher because the saturation temperature become higher when the water head become higher.
Quality Analysis of Fresh Rice Straw Wrapping Silage by Softening Treatment of Fresh Rice Straw and Colors Effects of Wrapping Stretch Film
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 335~340
DOI : 10.5307/JBE.2002.27.4.335
Recently, in Korea, round bale wrapping silage made by fresh rice straw are partially utilized. The colors of stretch film using far wrapping the fresh rice straw round bale are white, green and black. The light transmittance of green and white color stretch film was not founded the difference. However, the light transmittance of black color stretch film was largely difference of two stretch films. This study was carried out to measure qualities of fresh rice straw wrapping silage by softening processing of fresh rice straw and colors effects of wrapping stretch film. The analyzed factors were the light transmittance of stretch film, variation of the temperature in fresh rice straw round bale and qualities of the silage in crude protein, ADF, NDF, organic acid, etc. It was difficult to find in this study the colors effects of stretch film on silage qualities by the silage wrapping. But, when make fresh rice straw wrapping silage, wrapping silage fermentation effect goes well more if handle softening the fresh rice straw.
X-ray Image Processing for the Korea Red Ginseng Inner Hole Detection ( I ) - Preprocessing technique for inner hole detection -
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 341~348
DOI : 10.5307/JBE.2002.27.4.341
Quality evaluation of red ginsengs is determined by outer shape and inner qualities. Especially, the inner qualities are main grading criteria. Currently, red ginsengs are classified into 3-grades; heaven, earth and good. The best heaven grade must not include inner holes and sponge tissues. This study was conducted to develop a red ginseng sorting system using x-ray image processing technique. Because of lens characteristic, gray values of the central region in the x-ray image are higher and gradually decreased towards the edge regions. This difference of gray values gives trouble in segmentation and detection of inner holes in red ginseng image, so preprocessing technique is necessary. The preprocessing was done by subtracting source image from an empty background image. But, simple subtraction was not quite appropriate because of too small contrast between inner holes and sound part. Scaled subtraction images were obtained by multiplying all gray values by some numbers. However this method could not help to set threshold value because the gray values of root part are generally lower than body part when red ginseng is exposed to the x-ray. To determine threshold value for detecting inner holes, an algorithm was developed by increasing overall gray values of less clear images.
Development of Web-based Control System for Greenhouse Teleoperation
Journal of Biosystems Engineering, volume 27, issue 4, 2002, Pages 349~354
DOI : 10.5307/JBE.2002.27.4.349
In this study, we proposed a web-based teleoperation system to enhance the productivity and flexibility of the greenhouse since basically, internet-based teleoperation enables cheap, expandable system to be implemented. Platform independent language, Java-based control system can overcome the platform dependency which most of conventional control systems have. One of the merits of the proposed system is the flexibility of the data based system from which some valuable analysis can be implemented on-line. Some basic experiments show the stability and field applicability of the proposed remote control system.