• Korea-Australia Rheology Journal
• /
• 제19권3호
• /
• pp.171-176
• /
• 2007

LCD-BLU (Liquid Crystal Display-Back Light Unit) of medium size is usually manufactured by forming numerous dots with $50{\sim}300\;{\mu}m$ in diameter by etching process and V-grove shape with $50\;{\mu}m$ in height by mechanical cutting process. However, the surface of the etched dots is very rough due to the characteristics of the etching process and V-cutting needs rather high cost. Instead of existing optical pattern made by etching and mechanical cutting, 3-dimensional continuous micro-lens of $200\;{\mu}m$ in diameter was applied in the present study. The continuous micro-lens pattern fabricated by modified LIGA with thermal reflow process was tested to this new optical design of LGP. The manufacturing process using LIGA-reflow is made up of three stages as follows: (i) the stage of lithography, (ii) the stage of thermal reflow process and (iii) the stage of electroplating. The continuous micro-lens patterned LGP was fabricated with injection molding and its test results showed the possibility of commercial use in the future.

• 한국약용작물학회지
• /
• 제13권6호
• /
• pp.268-272
• /
• 2005

백수오 지주설치 생력화를 목적으로, 무지주 처리방법을 달리하여 백수오 중국도입종을 재배하고, 이에 따른 생육, 근수량 및 경영비를 검토한 결과를 요약하면 다음과 같다. 1. 관행 지주재배시 무지주 재배에 비해 생육이 양호한 경향이었으며, 무지주 처리 간에는 주만장과 주경의 총만장은 무처리, 적심, 선단예취 순으로 긴 반면, 경태는 선단예취, 적심, 무처리 순으로 굵었다. 선단예취시 엽수는 가장 적었으나 잎이 크고 엽당 무게가 무거운 편으로 이는 덩굴의 선단부 예취로 인해 수광면적이 확대됨으로써 광합성능률이 향상된 것으로 판단된다. 2. 지근의 수와 주근태는 지주재배와 선단예취에서 다소 많거나 굵었고, 주근장과 지근태는 지주재배와 적심 처리에서 길거나 굵었다. 3. 10a당 생근수량은 관행 지주재배시 1,918kg에 비해 무지주 재배시 $17.9{\sim}22.6%$ 감수되었으나, 지주생력화로 생산비가 감소됨으로써 경영비가 절감되어 소득이 $8%{\sim}17%$ 증가되었다. 무지주 처리방법 간에는 무처리에 비해 선단예취시 생근수량은 6%, 소득은 8% 각각 높았다.

• 화훼연구
• /
• 제18권1호
• /
• pp.33-37
• /
• 2010

겹꽃으로 개화하는 한국자생 산수국(Hydragea serrata for. acuminata)을 분화용 식물로 개발하기 위하여 알맞은 삽목시기를 구명하고 월별 삽목시기가 이듬해의 생육과 개화에 미치는 영향을 구명하고자 하였다. 본 실험은 2008년 3월부터 9월까지 매월 10일날에 직경 15cm 크기의 화분에 직접 삽목을 하여 재배한 결과, 초장은 5월에 삽목한 것이 31.7cm로서 가장 컷고 그 다음이 4월과 7월에 삽목한 것 이었으며 8월과 9월에 삽목한 것은 각각 23.6cm와 22.0cm로서 비슷하였다. 그러나 6월에 삽목한 것은 비정상적으로 작았고 생육도 매우 부진하였다. 잎은 8월 이후에 삽목했을때에 엽폭이 좁아지고 엽장도 짧아져서 엽면적이 감소되었으며 엽병장 또한 짧아졌으나 착엽수는 변화가 없었다. 주당 꽃송이의 수는 5월에 삽목한 것이 4송이로서 가장 많았고 7월부터 9월 사이에 삽목한 것은 3송이가 피었으며 6월에 삽목한 것은 1송이가 착화 되어서 가장 적었다. 화관의 크기는 5월에 삽목한 개체가 직경 10.3cm로서 가장 컷으며 7월이후부터는 삽목시기가 늦어질수록 화관의 크기가 감소되었다. 착화수나 꽃의 크기, 소화의 수 등의 개화 상태는 5월에 삽목한 것이 가장 양호하였고 6월에 삽목한 것이 가장 저조하였다. 그러나 8월과 9월에 삽목을 실시하더라도 이듬해에 관상가치가 있는 정상적인 꽃모양을 가진 꽃이 피었으나 개화시기는 약간 늦어졌다.

• 소성∙가공
• /
• 제15권1호
• /
• pp.57-64
• /
• 2006

High speed milling experiment on the hardened mold steel (CALMAX at hardness of HRC 55) is carried out using small diameter ball endmills. Tool lift and wear characteristics under the various machining parameters are investigated Effect of dynamic runout on the wear of the tool is also studied. For most of the cases, catastrophic chipping of tool edge is not observed and uniformly distributed wear on the flank surface of the tool is obtained. It is found that lower rate of tool wear is obtained as the cutting speed is increased. Also, high pick feed rate is found to be more favorable in terms of the tool wear and material removal rate.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.9-14
• /
• 1996

The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of radial cross sections of tile helical end mill is calculated for the determination of the relation between cross section and rigidity of tile tools. Using tile Bernoulli-Euler beam and and the concept of equivalent diameter, a deflection model is established, which includes most influence from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
• /
• pp.114-120
• /
• 2005

High speed milling experiment on the hardened mold steel (CALMAX at hardness of HRc 55) is carried out using small diameter ball endmill. Tool lift and wear characteristics under the various machining parameters are investigated. Effect of dynamic runout on the wear of the tool is also studied. For most of the cases, catastrophic chipping of tool edge is not observed and uniformly distributed wear on the flank surface of the tool is obtained. It is found that lower rate of tool wear is obtained as the cutting speed is increased. Also, high pick feed rate is found to be more favorable in terms of tool wear and material removal rate.

• 대한기계학회논문집A
• /
• 제39권10호
• /
• pp.1069-1077
• /
• 2015

발파를 이용한 터널굴착시, 와이어쏘를 이용하여 심빼기 부분 외곽에 불연속면을 발생시켜 발파진동을 차단함으로써 소음 및 진동을 저감시키고자 하는 방법은 타 방법에 비해 시공이 간편하고 경제적일 것으로 예상된다. 본 논문에서는 터널굴착용 와이어쏘의 절삭 메커니즘을 규명하기 위하여 시간에 따른 절삭 깊이 변화와 절삭 중 암석 내부의 와이어쏘 곡선 형태를 파악할 수 있는 절삭 모델을 구축하고 검증하였다. 구축된 모델을 이용한 시뮬레이션을 통해 터널굴착용 와이어쏘 절삭의 특징을 살펴보고, 와이어쏘 인장력, 와이어쏘 속도, 피드 속도, 천공 깊이 및 천공 직경과 같은 주요 조건들이 절삭 성능에 미치는 영향을 검토하였으며, 이러한 검토 결과를 바탕으로 절삭 성능을 높이기 위한 방안을 제시하였다.

• 한국잠사곤충학회지
• /
• 제39권2호
• /
• pp.101-105
• /
• 1997

Most of the mulberry saplings in Korea have been produced by grafting. But the production of mulberry sapling by this method is very complex process and requires high level of technique and two years to produce saplings. Therefore, to develop the mulberry sapling production system by softwood cutting method which is suitable for mass production, several conditions on rooting and growth of cuttings were investigated. The rooting ability of cuttings varied according to mulberry varieties, showing the highest rooting ratio of 93.3% in cultivar of Shingwangppong. Of different soil texture as for rooting media, the clay was found to be the best; other media decreased in order as follows; sand, sand loam and vermiculite. The shading ratio by 70% with polyethylene film showed the highest rooting ratio of the cuttings. Optimum day of cutting was around 50th day after sprouting, whereas the ratio of stem thicker than 7mm at the base of saplings in diameter was highest at 44th day.

• 한국정밀공학회지
• /
• 제20권11호
• /
• pp.71-78
• /
• 2003

The exit burrs in the micro-drilling of precision miniature holes are of interest, especially for ductile materials. As burrs from this process can be difficult to remove, it is important to acquire the way of predicting burr types as well as optimal cutting conditions which minimize the burrs. In this paper, an artificial neural network was used for the prediction of burr formation in micro-drilling. First, the influence of cutting conditions including cutting speed, feed and drill diameter on the exit burr characteristics, such as burr size and type, were observed and analyzed. Then. the burr types were classified by using the influential experimental data as input parameters to the neural nets.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.963-966
• /
• 2000

Abrasive jet machining(AJM) process is similar to the sand blasting, and effectively removes hard and brittle materials. AJM has applied to rough working such as deburring and rough finishing. As the needs for machining of ceramics, semiconductor, electronic devices and LCD are increasing, micro AJM was developed, and became the inevitable technique to micromachining. This paper describes the performance of the micro AJM in micro groove cutting of glass. Diameter of hole and width of line in this groove cutting is 80${\mu}{\textrm}{m}$. Experimental results showed good performance in micro groove cutting in glass, but the size of machined groove was increased about 2~4${\mu}{\textrm}{m}$. therefore, this micro AJM could be effectively applied to the micro machining of semiconductor, electronic devices and LCD parts.