• 한국약용작물학회지
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• 제20권5호
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• pp.353-358
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• 2012

This study was conducted to enhance the propagation of Acanthopanax divaricatus and Acanthopanax koreanum through different cutting practices. For propagation by cuttings, scions were taken on September 1. This already has hard skin and showed much higher values in terms of root length, root number, rooting ratio and root weight than those taken on June 30 and August 1. Regardless of cutting date, 50% shading resulted to the highest root length, root number, root ratio and root weight. Meanwhile, 95% shading significantly reduced these parameters compared with no shading. These results suggest that over-shading may inhibit root growth. Two growth regulators, IBA (concentration of 1,000, 2,000, 3,000 ppm) and Rootone-F (0.4%) were also tested of its effect to the cuttings. Rootone-F was found to be more effective than IBA. Cutting treated with Rootone-F had slightly higher root length and root number. A. koreanum which grows well in hot climatic condition showed better rooting ability than A. divaricatus.

• 원예과학기술지
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• 제30권6호
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• pp.686-693
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• 2012

NFT 수경재배 방식을 이용한 고구마 바이러스 무병주 대량 증식 기술을 개발하기 위하여, 버미큘라이트와 펄라이트(1:1, v/v)를 채운 72공 플러그 트레이(35mL/cell)에 삽목하여 양액 종류, 삽수 크기 및 품종에 따른 생육특성을 평가하였다. 무병묘의 줄기신장, 생체중 및 건물중 등은 일본원시배양액, 한국원시배양액, 야마자키 상추배양액의 순으로 양호한 생육을 보였다. 삽수 종류에 따른 무병묘의 생육은 줄기 정단 삽수에서 가장 양호하였으며, 삽수 크기가 클수록 줄기 길이, 생체중 및 건물중의 증가가 뚜렷하였다. 품종 간에는 '신자미'와 '연황미'의 줄기신장, 생체중 및 건물중 증가가 다른 품종에 비하여 양호하였다. 줄기 굵기와 뿌리 길이는 삽수 부위 및 크기와 품종 간에 유의차가 없었다. 1마디 삽수는 2마디 삽수와 생육특성에서 유의한 차이를 보이지 않았다. NFT 수경 재배에서 무병주 대량 증식 효율은 1마디 삽수와 정단 삽수를 이용하는 것이 효과적이었다.

• 한국생산제조학회지
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• 제22권3호
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• pp.402-407
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• 2013

In this paper, the image processing for flexible disk grinding and the effect of the grinding conditions on the flat zone length of a workpiece are investigated, with the purpose of automating the grinding process. To accomplish this, three issues should be carefully studied. The first is finding the relationship between the flat zone length and the grinding conditions such as the cutting speed and feeding speed. The second is developing a neural network algorithm to predict the flat zone. The third is developing an image processing algorithm to measure the flat zone length of a workpiece. Slope analysis is used to determine straight and curved sections during the image processing. For verification, the estimated length and the length from the image processing are compared with the length measured by a projector. There is a minimum difference of 1.7% between the predicted and measured values. The results of this paper will be useful in compiling a database for process automation.

• 한국생산제조학회지
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• 제9권4호
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• pp.34-47
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• 2000

Since carbon fiber epoxy composite materials have excellent properties for structures due to their high specific strength, high specific modulus, high damping and low thermal expansion, the hollow shafts made of carbon fiber epoxy composites have been widely used for power transmission shafts for motor vehicles , spindles of machine tools, motor base, bearing mount for tool up and manufacturing. The molded composite machine elements are not usually accurate enough for mechanical machine elements, which require turning drilling , cutting and grinding. The experiment are surface grinding wheel GC60 to the carbon fiber epoxy composite specimen with respect to staking angle [0]nT , [45]nT, [90]nT on the CNC grinding machine. In this paper, the surface grinding characteristics of composite plate, which are surveyed experimentally and analytically with respect to the grinding force, surface roughness and wheel loading according to the variable depth of cut, wheel velocity and table feed rate are investigated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.577-580
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• 2003

Stress state of chip formation zone is one of the main problems in metal cutting mechanics. In two-dimensional case this process is usually considered as consistent shears of work material along single of several shear surfaces. separating chip from workpiece. These shear planes are assumed to be trajectories of maximum shear stress forming corresponding slip-line field. This paper suggests new approach to the constriction of slip-line field, which Implies uniform compression in chip formation zone. On the base of given model it has been found that imaginary shear line in orthogonal cutting is close to the trajectory of maximum normal stress and the problem about its determination have been considered. It has been shown that there is a second central slip-line field inside chip, which corresponds well to experimental data about stress distribution on tool rake face and tool-chip contact length. The suggested model could be useful in solution of various problems of machining.

• 한국정밀공학회지
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• 제12권4호
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• pp.28-38
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• 1995

The flank wear at the minor cutting edge significantly affects the geometric accuracy and surface roughness in finish machining. A fuzzy estimator based on a fuzzy inference algorithm with a max-min composition rule is introduced to evaluate the minor flank wear length. The features sensitive to minor flank wear are extracted from the dispersion analysis of a time series AR model of the feed directional acceleration signal. These features, dispersions, are used for constructing linguistic rules, and then the fuzzy inferences are carried out with test data sets collected under various cutting conditions. The proposed system turns out to be effective for estimating minor flank wear length.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.111-117
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• 2004

The tool geometry parameters and cutting process have complex relationships. Until now, various cutting test were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process. In high speed machining. Using various tools with different geometry, relationships between tool geometry parameter (rake angle, clearance angle, length of cutter) and cutting process (cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining and developed tool geometry design S/W.

• 한국정밀공학회지
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• 제21권8호
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• pp.27-33
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• 2004

The ultra-precision cutting is a key technique for the manufacture of optical components such as aluminium mirrors, electroless nickel mirror, plastic mirror in a variety of advanced science and technology applications. The paper presents experimental results of ultra-precision diamond fuming of electroless nickel materials. In general, the cutting condition such as feed rate and depth of rut, have effect on the surface roughness in ultra-precision diamond turning. To obtain an optimal cutting condition, we studied the effect of the cutting speed. the tool length, the tool nose radius, the feed rate and depth of cut on the surface roughness. So, the relationship of the surface roughness and cutting condition has been clarified. From the experimental results, the machined surface roughnesses were obtained less than 1nm rms.

• 한국공작기계학회논문집
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• 제10권3호
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• pp.38-42
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• 2001

In the machining of glass fiber reinforced plastics(GFRP), turning has been often used. But the most of past studies have been interested in the effect of fiber orientation on tool wear. In this study, the effects of fiber contents and cutting speeds on tool wear, cutting force and surface roughness are investigated experimentally. By proper selection of cutting tool, the variables are cutting speed, fiber contents and cutting length with fixed feed rate and depth of cut. The fiber contents have major effects on coated tool wear which observed as abrasive wear type.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.67-70
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• 2001

The tool geometry parameters and cutting process have complex relationships. Until now, numerous cutting tests were needed to acquire optimal design of end mill for the purpose of high speed machining, due to the insufficient knowledge about cutting process in high speed machining. Using various tools with different geometry, relationships between tool geometry parameter(rake angle, clearance angle, length of cutter) and cutting process(cutting force, surface accuracy, surface roughness) have been studied. Acquired data can be used to design optimal tool for high speed machining