• 한국정보통신학회논문지
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• 제12권3호
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• pp.555-562
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• 2008

본 논문에서는 RTL 수준에서의 클록 게이팅을 이용한 실제적인 저전력 설계 기술에 대해서 제안하고자 한다. 상위 수준의 회로 설계자에 의해 시스템의 동작을 분석하여 클록 게이팅을 위한 제어기를 이용하는 것이 가장 효율적인 전력 감소를 가져 온다. 또한 직접적으로 클록 게이팅을 수행하는 것보다는 합성툴이 자연스럽게 게이팅된 클록을 맵핑할 수 있도록 RTL 수준에서 유도하는 것이 바람직하다. RTL 코딩 단계에서부터 저전력이 고려되었다면 처음 코딩단계에서부터 클록을 게이팅 시키고, 만일 고려되지 않았다면 동작을 분석한 후에 대기 동작인 부분에서 클록을 게이팅 한다. 그리고 회로의 동작을 분석한 후에 클록의 게 이팅을 제어하기 위한 제어기를 설계하고 합성 툴에 의해 저전력 회로에 해당하는 netlist를 얻는다. 결과로부터 상위수준의 클록 게이팅에 의해 레지스터의 전력이 922 mW에서 543 mW로 42% 감소한 것을 확인할 수 있다. Power Theater 자체의 synthesizer를 이용하여 netlist로 합성한 후에 전력을 측정했을 경우에는 레지스터의 전력이 322 mW에서 208 mW로 36.5% 감소한 것을 확인할 수 있다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.151-156
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• 1995

This paper presents a methodology for real-time detecting and identifying the runout geometry of an end mill. Cutter runout is a common but undesirable phenomenon in multi-tooth machining such as end-milling process because it introduces variable chip loading to insert which results in a accelerated tool wear,amplification of force variation and hence enlargement vibration amplitude. Form understanding of chip load change kinematics, the analytical sutting force model was formulated as the angular domain convolution of three dynamic cutting force component functions. By virtue of the convolution integration property, the frequency domain expression of the total cutting forces can be given as the algebraic multiplication of the Fourier transforms of the local cutting forces and the chip width density of the cutter. Experimental study are presented to validata the analytical model. This study provides the in-process monitoring and compensation of dynamic cutter runout to improve machining tolerance tolerance and surface quality for industriql application.

• Structural Engineering and Mechanics
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• 제61권4호
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• pp.519-526
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• 2017

In the present paper, the effects of cutting parameters and coating material on the performances of cutting tools in turning of AISI 52100 steel are discussed experimentally. A comparative study was carried out between uncoated and coated (with TiCN-TiN coating layer) cermet tools. The substrate composition and the geometry of the inserts compared were the same. A mathematical model was developed based on the Response Surface Methodology (RSM). ANOVA method was used to quantify the effect of cutting parameters on the machining surface quality and the cutting forces. The results show that feed rate has the most effect on surface quality. However, cutting depth has the significant effect on the cutting force components. The effect of coating layers on the surface quality was also studied. A lower surface roughness was observed when using PVD (TiCN-TiN) coated insert. A second order regression model was developed and a good accuracy was obtained with correlation coefficients in the range of 95% to 97%.

• 대한수의학회지
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• 제34권2호
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• pp.327-333
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• 1994

The purpose of this study was to establish a rapid diagnostic method detecting Aujeszky's disease virus (ADV) DNA in the cultured cell monolayers (PK-15) and tissue sections of ADV(NYJ-1-87)-infected rats and pigs by in situ hybridization(ISH). Detection of specific ADV-DNA in infected cells was conducted by radiolabeled ISH method using $^{32}P-labeled $ DNA probe (BamH1 7 fragment) which contains a 6.3 Kb ADV-DNA insert. Where ADV-DNA was detected by radiolabeled ISH, the deposition of black photographic grains occurred in the nuclei and the cytoplasms of ADV-infected cells. Positive hybridization signal was often observed in the spinal trigerminal nucleus of the pons, the nucleus of the trigerminal ganglion neuron and the epithelial cells of tonsillar crypts. The results suggested that ISH is considered as a highly sensitive and reliable tool for confirmative diagnosis of this viral disease.

• 한국자동차공학회논문집
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• 제13권1호
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• pp.45-50
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• 2005

Stick type ignition coil(called a Cigar coil) is a kind of transformer for an automobile modulaized of distributer and electric cable. A material of cigar coil is PBT $GF30\%$ resin. This is an excellent engineering plastic with both mechanical and electrical properties. When we insert an HV terminal into the PBT $GF30\%$ resin jacket, it breaks the jacket, because the HV terminal is bigger than the jacket. It is a fatal on durability of a part. In this study, We used ANSYS FEM tool in order to stress analysis by contact. In order to automatically estimate possible maximum diameter of an HV terminal, we used an APDL. In the contact part, we considered the relation of the HV terminal's diameter with the amount of stress that occurred. This relation is able to be applied, in part, to the dimensions of the part design.

• 대한기계학회논문집
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• 제16권12호
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• pp.2340-2348
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• 1992

본 연구에서는 드릴(SKH9종)에 스퍼터링법으로 Ti 중간층을 약 0.2$\mu\textrm{m}$의 두께 로 코팅한후, 그 위에 플라즈마 화학증착법으로 TiN박막을 코팅한 드릴로 드릴링 시험 을 행하여 수명을 평가하였으며, 드릴의 내마멸성 및 드릴링한 구멍 내면의 조도를 코 팅하지 않은 드릴 및 TiN 코팅한 드릴과 비교하므로서 Ti/TiN코팅처리에 의한 공구성 능 및 수명향상 효과를 평가하고자 하였다.

• 한국분말재료학회지
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• 제11권5호
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• pp.399-411
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• 2004

Crack generation during die compaction and distortion during sintering have been critical problems for the conventional pressing and sintering process. Until now, trial and error approach with engineers' industrial experiences has been only solution to protect the crack generation and distortion. However, with complexity in shape and process it is very difficult to design process conditions without CAE analysis. We developed the exclusive CAE software (PMsolver/Compaction) for die compaction process. The accuracy of PMsolver is verified by comparing the finite element simulation results with experimental results. The simplified procedures to find material properties are proposed and verified with iron based powder and tungsten carbide powder. Based on the accurate simulation result by PMsolver, the optimal process conditions are designed to get uniform density distribution in a powder compact after die compaction process by using a derivative based optimization scheme. In addition, the effect of non-uniform density distribution in a powder compact on distortion during sintering is shown in case of the fabrication of tungsten carbide insert.

• 한국가스학회지
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• 제9권2호
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• pp.38-42
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• 2005

본 연구는 LP가스 용기용 밸브의 개발에 관한 것으로 안전밸브의 개념을 도입했다. LP가스 용기는 사용의 편리성 때문에 많이 이용되고 있지만 많은 사고가 발생되고 있다. 특히 자해나 남을 해할 목적으로 이용되기도 하며 때때로 시위도구로 사용되기도 한다. 정부에서는 이와같은 사고를 줄이기 위하여 과류밸브를 사용하도록 의무화하고 있지만 제품개발이 뒤따르지 못하고 있는 실정이다. 본 연구에서는 과류밸브보다 근원적 안전개념을 도입한 안전밸브의 개념을 소개한다. 이것은 기존의 밸브에 모듈을 삽입하는 방법으로 개발되었으며 밸브에 호스나 조정기가 연결되지 않은 상태에서는 가스의 흐름이 억제된다. 또한 정상 사용중이더라도 호스가 절단되거나 과류가 발생되면 즉시 가스의 흐름은 차단된다.

• 한국정밀공학회지
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• 제21권6호
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• pp.188-196
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• 2004

The objective of this paper is to propose a new technology of the orthopaedic surgery using the combination of reverse engineering (RE) based on CT data and rapid prototyping (RP). The proposed technology utilizes symmetrical characteristics of the human body and capability of the combination of RE and RP, which rapidly manufactures three-dimensional parts from CT data. The original .stl data of injured extents are generated from the mirror transformation of .stl file fur uninjured extents. The physical shape before injuring is manufactured from RP using the original .stl data. Subsequently, pre-operative planning, such as a selection of proper implants, preforming of the implant, a decision of fixation locations and an insert position for the implant, an estimation of the invasive size, and pre-education of operators are performed using the physical shape. In order to examine the applicability and the efficiency of the proposed surgical technology, various case studies, such as a distal tibia commented fracture, a proximal tibia plateau fracture and an iliac wing fracture of pelvis, are carried out. From the results of case studies, it has been shown that the proposed technology is an effective surgical tool of the orthopaedic surgery reducing the operational time, the operational cost, the radiation exposure of the patient and operators, and morbidity. In addition, the proposed technology could improve the accuracy of operation and the speed of rehabilitation.

• 한국산학기술학회논문지
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• 제15권1호
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• pp.21-26
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• 2014

치과에서 사용되는 구강 치료용 요오드 용기는 개폐 시 용기의 캡에 부착되어 있는 칼날에 의해 치료용 실은 절단이 된다. 금속의 칼날은 요오드 용액과 반응하여 단기간에 부식이 되는 문제로 인해 환자의 위생에도 영향을 준다. 이러한 문제를 해결하기 위해 최근 세라믹 칼날로 대체되어진 제품들도 개발되어 생산되는데, 이때 세라믹 칼날은 수작업과 기계가공을 통해 만들어 진다. 본 연구에서는 세라믹 칼날을 분말사출성형공정으로 대량 생산할 수 있도록 20Cavity의 균일 충전을 위한 유동 시스템을 제안하였다. Moldflow를 이용하여 20cavity 유동성에 대한 시뮬레이션을 진행하였고, 금형제작과 수정을 통해 금형을 완성하였다. 사출성형 후 탈지와 소결공정을 통해 완성하고, 금형에 세라믹 칼날을 인서트 사출하여 캡 제품을 완성하였다. 본 연구를 통해 유효한 절단 성능을 갖는 세라믹칼날 대량생산 가능성을 검증하였다.