• 디자인학연구
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• 제16권1호
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• pp.251-260
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• 2003

근무환경을 개선함으로써 업무효율이 높아지는 것이 자명한 상황에서 사무환경의 중요한 요소인 공간구획용 패널의 연구 개발은 필수적이다. 단순히 물리적 환경만이 아니라 심리적, 생리적, 경제적 환경까지 고려할 때 조립형 벽체 패널의 요구 조건으로는 차음/흡음 성능, 통신설비 설치 용이성 등을 포함한 기능적 요소, 최초 설치비용, 재활용성, 설치 용이성 등의 경제적 요소, 최종 마감 재질 및 형태 둥을 통한 시지각적 만족도를 위한 심미적 요소, 구조적 안정성, 건강성 등을 포함하는 안전 요소 등이 포함된다. 제품 개발을 통한 분석 결과, 재활용성을 높이고 현장작업의 축소 및 제품완성도를 높이기 위해 프레임식 구조의 장점을 살린 패널식 구조의 연구가 요구된다. 공장에서 많은 공정이 이루어질 수 있는 패널식 부재는 제품의 완성도를 높일 수 있는 장점이 있으나 시공현장에서의 융통성이 떨어질 수 있다. 따라서 현장 조건의 완성도가 낮아 발생하는 문제를 보완할 수 있는 디테일의 개발이 요구된다. 더불어 환경적 쾌적성에 영향을 주는 차음 및 흠음 성능, 안전과 건강을 고려한 디자인 및 재료에 대한 지속적 연구가 요구된다.

• 한국기계가공학회지
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• 제10권1호
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• pp.80-86
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• 2011

This study compared and analyzed manual tapping and automatic tapping regarding tapping process characteristics of titanium hard-to-cut-material. Tapping process characteristics of titanium hard-to-cut-material are evaluated as the quality of a screw, wear of a tap, economic analysis, and cycle time etc. The type of screw threads after manual tapping is formed as an irregular type of screw threads, and perfect screw threads are created after automatic tapping. In addition, the chip type after manual tapping process is formed as the discontinuous chip due to work hardening, and the powder type of chip after automatic tapping process is created. In terms of cycle time, an automatic tapping process is shortened by 70% compared to manual tapping process. Insert tip wear of an automatic tapping shown in the process of 5-hole tapping is not found, but hand tap wear for finish cutting is most severe.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.3-8
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• 2004

When most manufacturing company produce grinding product operators decide grinding condition by experience and subjective judgment. The study on grinding manufacture have been developed to get the grinding condition with the same result when non-experienced or experienced worker work. The objective of this study is to develope the grinding condition and predict the result of grinding by neural network. Several discussions were made in following areas as; getting MRR with image processing, the architecture optimization of neural network with experiment design, analysis of the input neurons using sensitivity approach. The results showed that the developed approach was the best method in predicting grinding condition with respect to surface finish quality.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.251-254
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• 1995

The quality and functionality of machined products is determined by surface finish. The surface roughness is characterized by roughness parameters such as R $_{a}$ and R $_{max}$. While such parameters are useful to define the quality of surface, they are nor sufficiently descriptive characteristics of surface. The fractal dimension which can describe characteristics od surface roughness than conventional roughness parameters has been applied. In this work, Relation between fractal dimension and surface roughness will be examined as a means of characterizing surface roughness.s.s.

• 한국정밀공학회지
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• 제19권12호
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• pp.142-149
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• 2002

In this paper, the metal forming process is caused of rise of the unit cost of production in increase of the lead-time and cost because of manufacturing final product through a few the number of processes. Flow control complex forming is proposed to put into formulation in order to apply cold forging from conventional approximate similarity theory, and the forming loads of the real material(AISI 1008) can be calculated by put at the new similarity formula the load by plasticine model material experiment through hub clutch. In order to reduce lead-time and cost the technology is used to manufacture with lower die of this product. By the application synthetic resin as the raw material, it is have the merit such short lead-time, low cost, good surface finish etc., as compared with the machine work.

• 한국생산제조학회지
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• 제8권3호
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• pp.76-82
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• 1999

This study was carried out to verify finding performance of dental diamond bur and investigate the possibility of AE application in density field. Work pieces were made of acryl and bovine respectively for the experiments in this study. Grinding test was conducted to get the data of grinding resistance and specific finding energy of low different types of diamond bur by using tool dynamometer. AE signal was acquired to verify grinding process in the AE measuring system. AErms value was increased as the grinding velocity and depth were increasing, but it decreased as the feed rate was increasing. The case of the small value of AE signal is due to abnormal grinding in D type diamond bur. By analyzing AErms start and finish time of grinding working, abnormal grinding state can be confined. Abnormal state can be found through the behavior of AE signal in the finding working. As a result, it is expected that forecast of abnormal state is possible using AE equipments under real time process.

• 한국화재조사학회지
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• 제11권1호
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• pp.75-90
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• 2007

본 논문에서는 국내에서 옥외에 설치한 계기용변성기의 화재원인을 분석한 것이다. 이는 KSC IEC와 같은 공인된 규정에 의해 준수되었고, 현장에서 입증이 가능하도록 전개되었다. 결과적으로, 공정의 마무리가 불량한 계기용변성기의 개스킷 부분에서 화재 원인을 찾아내었다. 화재 과정을 추정하면, 미체결 개스킷에 기인한 계기용변성기에 수분이 침투한 것이다.

• 대한수학회보
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• 제29권2호
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• pp.201-204
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• 1992

After this discovery of lower bounds by Stark and Odlyzko, some people searched for number fields with relatively small discriminants. Also some others studied algorithms which will produce number fields with the smallest absolute value of the discriminant for a fixed degree n. However, this algorithmic approach does not work well if the extension degree n is greater than seven or eight. And it is not clear whether current computers can finish those algorithms in a reasonable amount of time for large n. So we are justified in our approach for this subject. In this paper we will report the results of our computations. Some number fields we found are better than previously known examples. Others are rediscoveries of known examples. However, there is theoretically nothing new in our approach to this subject.

• 한국정밀공학회지
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• 제17권7호
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• pp.90-97
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• 2000

This paper presents a methodology to analyze the cutting fluid effectiveness in mechanical and thermal terms simultaneously using finite element method and experimental work. Cutting fluid plays many roles in metal cutting process. Mechanically-thermally coupled effectiveness of cutting fluids affect to friction coefficient at tool-workpiece interface and cutting temperature and chip control, surface finish, tool wear and form accuracy. Through this study, it can be explained that the critical behavior of cutting fluids will be able to apply optimal environmentally conscious machining process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.73-78
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• 1994

Wear and fracture mode of ceramic tool for hardened SKD11 steel was investigated by face milling in this study. The cutting force and Acoustic Emission(AE) signal were utilized to detect the wear and fracture of ceramic tool. The following conclusions were obtained : (1) The wear and fracture modes of ceramic tool are characterized by three types: \circled1wear which has normal wear and notch wear, \circled2 wear caused by scooping on the rake face, \circled3 large fracture caused by thermal crack in the rake face. (2) The wear behaviour of ceramic tool can be detected by the increase of mean cutting force and the variation of the AE RMS voltage. (3) The catastrophic fracture of ceramic tool can be detected by the cutting force(Fz-component). (4) As the hardness of work material increased, Acoustic Emission RMS value and mean cutting force(Fz) increased linearly, but the tool life decreased.