• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.75-80
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• 2005

Mechanical characteristics of flower stalks (scapes) of garlic such as shear forces, cutting forces, and modulus of elasticities were investigated as a preliminary research to develop a mechanical harvester of garlic bulbils. The average shear forces of garlic scapes was 0.642 N and the maximum and minimum shear forces were 1.42 and 0.25 N, respectively. The shear forces generally increased as the diameter of garlic scapes increased. There was no correlation between the modulus of elasticity and the diameter of garlic scapes and the average modulus of elasticity of garlic scapes was around $2.40\times10^7\;N/m^2$ There was also no correlation between the cutting force and the diameter of garlic scapes. As the downward speed of blade increased, the cutting force of garlic scapes decreased and reversed to increase. The cutting forces of the lower part garlic scapes were lower than those of the upper part. The range of cutting forces of the lower and the upper part of garlic scapes were 3.88-4.04 N and 4.29-4.93 N, respectively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.102-106
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• 1996

In the ball end-milling process of a 3-dimensional mold, it is important to select cutting conditions and tool path considering the geometrical shape of a workpiece to reduce machining time. In this study, experiments were performed to decide allowable feed rate not breaking stability of system for different geometrical shapes. It was found that downcut is more stable than upcutting in machining side wall and downward is preferable to upward in inclined part depending on the angle of the inclination and depth of cut.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.7
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• pp.8-13
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• 2019

As increasing demand for precise machining in advanced disciplines, especially in semi-conductor, aeronautical and automotive industries, the magnetic abrasive deburring(MAD) which is able to eliminate micro-sized burr on complex surface in less time has drawn the attention in the last decades. However, the performance of MAD is subject to shape and size of a tool. Therefore, this study aim to identify deburring behavior of MAD in U-type flow channel by measuring the length rate of burr removal in radial distance of the cylindrical tool under four process factors. In order to evaluate the deburring effect of MAD on the surface, finishing regions are divided based on center of the circular cutting tool. As a results, it was defined that the amount of burr removal in a downward direction moving toward flow channel from the top surface was higher than upward direction. This is because the magnetic abrasives were detached from magnetic lines of force due to geometrical shape.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3897-3920
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• 1975

Since the most of Korean dairy and cattle raising farms are too small to introduce western mechanized farming, it is necessary to develope small size equipments. This study has been carried to develop a rotary mower as on attachment of 8 to 10 horse powertiller which is widely spread in rural area. It will not ony be helpfull for the farmers to harvesting hay grass but also desirable to increase the power tiller utility. The protto type rotary mower designed through the fundamental investigations, has been modified and improved through the field trials, and a series of field tests has been carried to investigate its performance and economic feasibility comparing with existing vailable harvesting equipments. The results are as follows; 1. To increase the stability, two guide wheels are attached to both side of the protto type rotary mower. 2. To prevent the clinging of tall grasses, the vertical driving shafts are covered with cylindrical protectors. 3. The cutting height is adjustable in 8 steps from 2.5 to 20 centimeters by changing the length of guide wheel legs. 4. The practical Critical cutting speed were always higher than theoretical value in both case of single cutting blade and three when the cutting depth was 25 millimeter. 5. The peripheral speed of cutting blade was varied in response to the change of engine speed, mean while the peripheral speed was adequate as it was changhed from 25 to 35 meter per second when the power tiller is operated in proper working ground speed. 6. The time requirement to harvest 10 a were 88.7, 54.6 and 41.4 minutes for the first, second and third stage of ground speed respectively, and because of the difficulty of delivery, it was observed that operating with fourth stage of ground speed was not recomanendable when the grass height is taller than 90 centimeters. 7. The performance of rotary mower were 1.1-1.7, 1.4-4.0, 3.8-11.8 and 7.4-22.0 times of reciprocating mower, portable disc type cutter, hay scythe and ordinary sickle respectively. 8. When the slope exceeds, 20 degree the downward harvesting operation was impossible because of the excessive front end weight, while less than 5 degree of land slope did not effect in field operation. 9. Increased traveling spee caused higher cutting height and slight cutting failure, but seems not to effect to the gross yield, and the efficiency of cutting width were from 83 to 94 precent. 10. Tn rank of economy were rotary mower (3,2 stage operation), reciprocating mower, hay scythe, portable disc type cutter and sickle in order when the annul operation exdeeds 100 hours. From the above results, it is convinced that the protto type rotary mower is good enough to the livestock farmers as a hay harvesting equipment because of its economy, hardiness in operating and its out standing performance and hopefully it will contribute to the extension of Korean livestock farming.

• Restorative Dentistry and Endodontics
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• v.39 no.4
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• pp.276-281
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• 2014

Objectives: The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods: The apical 3 mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results: There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions: Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.5
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• pp.40-48
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• 2013

Eco deck plate system is a construction method that deconstruction of galvanized steel sheets is possible by integrating steel-wire-integrated girders and the galvanized steel sheets with bolts. Therefore, compared with previous steel-wire-integrated deck plates which were joined by welding, the system is acknowledged as the construction method possible management and repair. This study conducted an experimental research by manufacturing total 24 full size specimens in a same condition for 12-shape specimens by two parts to evaluate structural behaviors of the eco deck plates. In the results after the test, permissible deflection for the construction load action was shown to be values under design values and satisfactory. The processing of lattice steel wires was presented to be structurally advantageous in being manufactured by cutting downward. Also, in case of a specimen that D13 as a steel wire was used, destruction occurred at the welding part of the bottom steel wire and the lattice steel wire, so improvement measures for the welding in factory manufacture are necessary.

• The Journal of Internal Korean Medicine
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• v.10 no.1
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• pp.65-80
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• 1989

About Oui-Ga-Sil(胃家實) in order to considerate the contents recorded in Nai-Gyung Sang-Han-Lon and latter literature, definition, etiopathology, syndrome, differential diagnosis, therapy, Prognosis and prevention were classified. And the results were as follows: 1. Oui-Ga(胃家)was a term which indicated the whole digestive system such as stomach, small intestine, large intestine, rectum and anus. Sil(實)could be defined as the peculiar concept pertaining to the acute and last stage which was invaded to inside bowels because of abundance with evil influence. 2. Eliology of Oui-Ga-Sil was abunt gastric fever originally, injured mucus because of mistreatment, the invasion to inside of outside evil influence through meridian. Pathology was the opening and shutting appearance of gastric abundance with intestinal emptiness, and intestinal abundance with gastric emptiness, Oui-Ga-Sil could be occurred because of gastric abundant dryness and splenic humidifying capacity decrease. 3. Symptom of Oui-Ga-Sil was classified as for the sunlight outside syndrome and the inside abundant syndrome. The sunlight outside syndrome was body fever, sweating, no chilling, on the contrary hatred of fever. The chief complaint of inside abundant syndrome was daily fever, talking in delirium, hand and foot sweating, abdominal distention, difficult defection and those could be pertained to sunlight bowel syndrome. 4. Diagnostic views of Oui-Ga-Sil were that pulse was descending abundant large strong and smooth quick, a coated tongue was yellow, deep yellow, old yellow, thick, scorching dry rough or gray black. On abdominal diagnosis, pressing by hand, patient was conscious of pain, excessive pain, rejection against press, impossible press or intermittent abdominal pain and bowel cutting pain without press. 5. Differential diagnosis was that the sunlight of Nai-Gyung-Fever-Theory was outside desease making meridian the prime object, Baik-Ho-Tang syndrome was making figureless abundant fever the pivotal point. And important differential standard of splenic shrink syndrome was that a daily fever, an irritation with fever were not occurred. 6. Theory of Oui-Ga-Sil was that Seng-Gi-Tang classes had been used in attacking downward or making balance, and moxibustion on Jung-Wan, honey boiling induction theory had been also used. Attacking downward therapy was invigorating method to preserve mucus, and if mucus had been exausted with complicating emptiness prognosis had been appeared badly. 7. Preventing from Oui-Ga-Sil diet by rule, fitness to cold and warmth may be needed to prevent outside evil influence attack and inside evil influence occurrence. Prudence with being very busy, fatigue, wine and woman may be also needed not to be an injury to splanic and gastric spirit.

• Journal of the Korean Institute of Gas
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• v.10 no.3 s.32
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• pp.54-59
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• 2006

A safety device with shut-off function was developed for preventing intentional accidents that might happen by separating of cutting hoses connected to pressure regulators used in residential LP gas facility. For the verification of function and field adaptability, the safety device with shut-off function was tested in the state of joining the device to the regulator and a field test was carried out at home. This study shows that, at the inlet pressure of 0.07-1.56 MPa, the device shuts off the gas within the 5m length of hose regardless of the installation condition of the regulator. The shut-off flow rate increases in the order of perpendicular upward, horizontal and perpendicular downward. From the results of the field tests carried out at home for 5 months, there appears no problem using a gas range or a boiler. If the developed shut-off device is commercialized and distributed in the market the intentional accidents occurred by cutting or separating hoses can be prevented remarkably.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3627-3641
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• 1975

The Government is trying to increase total food grain yield to meet national self sufficiency by means of increasing unit yield as well as extending crop land, and this year he set the target of 321,000 hectare of forest to clear for cropping. This study was carried to investigate the most efficient method of clearing hillock by bulldozer, and successful method to develope yielding potential of newly cleared land in short term. Since the conventional land clearing method is just earth leveling and root removing neglecting top soil treatment, the growth of crop was poor and farmer tends not to care the land. The top-soil-furrowing method is applied through out this study, that is advantageous especially for the land having shallow top soil and low fertility like Korean forest. In this study, various operating method were tried to find out most efficient method separately in connection with the land slope less than 25 percent and over, and several fertilizing methods to develop yielding potential. The results are as follows; 1) For the natural land slope utilization method, applicable to the land having less than 25 percent slope, reverse operating was more efficient than using forward gear of bulldozer. The operating time was 3 hour 32 minutes and 36 seconds using forward gear was 2 hour 32 minutes and 30 seconds for reverse gear operation per 1,000 square meter. 2) Bulldozer having angle blade adjustment needed 7hr 15min. for constructing of terrace per 10a compaire with the one having angle & tilt adjustment needed 6hr 4min for same operations. Specially there is significant difference for operation time of first period (earth cutting) such as bulldozer having angle blade adjustment needed 3hr 56min compaired with the one having angle & tilt adjustment 3hr 59min. In construction of terrace, the bull-dozer having tilting and angle blade adjustment was most suitable and performed efficiently. 3) For the fertilizer application treatment, the grass (Ladino clover) yield in first year was almost same as ordinary field's in the plot applied(N.P.K+lime+manure) while none fertilizer plot showed one tenth of it, and (N.P.K.+lime) applied plot yielded on third. 4) The effect of different land clearing method to yield showed significant difference between each treatment especially in the first year, and the conventional method was the lowest. In the second year, still conventional terracing plot yielded only half of ordinary field while the other plots showed as same as ordinary field's. 5) The downward top soil treatment plot showed most rapid improvement in soil structure during one year physio chemically, it showed increase in pH rate and organic composition, and the soil changed gradually from loam to sand-loam and the moisture content increased against the pF rate, and it gives good condition to grow hay due to the increase of field water capacity with higher available water content. 6) Since the soil of tested area was granite, the rate of soil errosion was increased about 2 to 5 percent influencing in soil structure more sand reducing clay content, and an optimum contour farming method should be prepared as a counter measure of errosion.

• Journal of the Korean association of regional geographers
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• v.7 no.2
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• pp.71-81
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• 2001

According to the change of stream power/resisting power relationship due to the crustal movement or the climatic change, most channel landforms which reflect the equilibrium state of fluvial system are eroded and a part of them is remained as a river terrace. In many rivers in Korea are extensively distributed the relatively younger low river terraces. But their accurate formation mechanism is not known. In this paper, the formation processes and the dating of low river terraces distributed in Nakdong River basin will be investigated. Stream power of the downward erosion was revived because the sea level fell down. So stream power was superior to the resisting power under the cool-wet climatic condition during the last glacial period. Thus the river bed was excavated deeply, so that low river terraces were built up. And many incised meander loops were cut during this period. But, when fluvial system did not have equilibrium over all reaches, the last glacial period ended and the sea level initiated to rise rapidly. The headward erosion from the fall of sea level during the last glacial period had kept up to Hagye Fall because of the cutting of incised meander loops. Deeply excavated valleys and abandoned channel of cut-meander in lower reaches of a stream were filled with sediments. Thus the longitudinal profile of the uppermost reaches reflect the last interglacial, the upper reaches the last glacial, and the middle/1ower reaches recent fluvial system. Therefore low river terraces have been formed since the last glacial period.