• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.86.2-86.2
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• 2014

양경규일의(兩景揆日儀)는 세 개의 목판을 이용하여 시간과 계절을 알 수 있는 조선후기에 사용한 해시계이다. 이상혁(李尙赫)과 남병철(南秉哲, 1817~1863)은 각각 "규일고(揆日考)"와 "의기집설(儀器輯說)" "양경규일의(兩景揆日儀)"에 이에 대한 설명과 제작법 등을 기술하였다. 현존하는 양경규일의의 유일한 유물은 헌종 15년(1849)에 제작한 것으로 고려대학교박물관에 소장되어 횡표입표일구(橫表立表日晷)라는 이름으로 전시되어 있다. 그러나 아직 세부적인 검토와 연구가 미진하여 많은 문헌과 인터넷 사이트에는 잘못된 설명이 제시되고 있다. 문헌기록을 살펴보면 계절이 표시된 2개의 입판(立版)과 또 다른 2개의 횡판(橫版)으로 구분되어 있다. 각 절후는 13개 곡선의 절후선 사이에 초후(初候) 중후(中候) 말후(末候)로 3등분하여 모두 37개의 절후선이 그려져 있고, 12시(時) 시간을 알리는 표시가 있다. 우리는 이상혁과 남병철의 문헌에 대한 세세한 분석을 통해 과학적 원리분석과 복원 설계 등을 진행하고, 실제 유물을 재현하여 천문학적 검증작업을 통해 과학적 규명을 수행하였다. 아울러 이와 유사한 동서양의 해시계와 서로 비교하였다.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1105-1108
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• 2004

As recently optical communication industry is developed, request of optical communication part is increased. Ferrule is very important part which determines transmission efficiency and quality of information in the optical communication part. Most of ferrule processes are grinding which request high processing precision. The ultra precision centerless grinding machine for ferrule grinding was designed. The centerless grinding machine is composed of the high damping bed, grinding wheel spindle unit, regulating wheel spindle unit, feeding table and dressing unit. Reliability prediction was very important for the high quality design. In this study, centerless grinding machine was predicted reliability.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.40-44
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• 2005

Recently PZT is used in ultra precision mechanism field. PZT itself has a small driving range although it has a high resolution. Many methods, such as inchworm, impact driving, inertial sliding method, etc., have been applied for moving range expansion. In this study, a new actuating mechanism for rotational motion with two driving PZT is proposed. The Fixed-Fixed beam support is applied for compensation of the difference in driving force between expansion and contraction of PZT. The behavior and design parameters of the proposed mechanism are analyzed for improving performance.

• Korean Journal of Computational Design and Engineering
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• v.14 no.4
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• pp.254-260
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• 2009

Most commercial PDM (product data management) systems, which have been released recently by overseas famous software vendors, are still expensive and heavy to apply to small and medium enterprises (SMEs). Proposed in this paper are an architecture and functions of collaborative BOM (bill-of-material) management system (cBOM-MS) which supports the internal BOM management by BOM Navigator, provides SMEs with constructing the collaborative BOM via Collaborative BOM Portal, and proposes an interface to extract BOM automatically from commercial CAD systems. In the design of cBOM-MS, BOM Navigator and cBOM Portal are positioned separately to reinforce the information security about product data during product development process.

• Korean Journal of Computational Design and Engineering
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• v.14 no.5
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• pp.338-345
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• 2009

c-PMS(collaborative project management system) is a business process(BP) based tool to manage collaborative projects which accomplish common business objectives determined by mutual agreement of companies using limited resources and time. This study analyzes collaborative BP, collaborative projects, and their relation, and proposes the architecture and operation scenario of c-PMS consisted of business process asset management(BPAM) sub-system and project manage(PM) sub-system. BPAM sub-system models private and public BP using a client/server based modeler, defines collaborative BPs process from public BPs, and manages them as companies' asset on a web portal. PM sub-system globally manages collaborative project using planning, execution, monitoring, and analyzing functions.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2004.05a
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• pp.223-228
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• 2004

Miniaturization is the central theme in modern fabrication technology. Many of the components used in modern products are becoming smaller and smaller. The direct write FIB technology has several advantages over contemporary micromachining technology, including better feature resolution with low lateral scattering and capability of maskless fabrication. Therefore, the application of FIB technology in micro fabrication has become increasingly popular. In recent model of FIB, however the feeding system has been a very coarse resolution of about a few $\mu\;\textrm{m}$. It is not unsuitable to the sputtering and the deposition to make the high-precision structure in micro or macro scale. Our research is the development of nano stage of 200mm strokes and 10nm resolutions. Also, this stage should be effectively operating in ultra high vacuum of about $1\times10^{-7}$ torr. This paper presents the concept of nano stages and the discussion of the material treatment for ultra high vacuum.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2004.05a
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• pp.229-233
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• 2004

The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. This paper was carried out some experiments of the micro plasma electrode fabrications using FIB. The sputtering of FIB has one major problem that is redeposited by sputtered material including $Ga^+$ ion source. Therefore we have verified the effect of the reposition by EDX. And the optimal condition is suggested to machine the micro plasma electrode.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.5 s.170
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• pp.175-180
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• 2005

The application of focused ion beam (FIB) technology in micro/nano machining has become increasingly popular. Its use in micro/nano machining has advantages over contemporary photolithography or other micro/nano machining technologies such as small feature resolution, the ability to process without masks and being accommodating for a variety of materials and geometries. In this research, fabrication of micro plasma electrode was carried out using FIB. The one of problems of FIB-sputtering is the redeposition of material including Ga+ ion source during sputtering process. Therefore the effect of the redeposition was verified by EDX. And the micro plasma electrode of copper was fabricated by FIB.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.608-611
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• 2005

As the optical communication industry is developed, the demand of optical communication part is increasing. $ZrO_2$ ceramic ferrule is very important part which can determines the transmission efficiency and information quality to connect the optical fibers. In general $ZrO_2$ ceramic ferrule is manufactured by grinding process because the demands precision is very high. For the precision grinding machining, it is very important that the error of feeding system is improved. Therefore, we estimated the dynamic characteristics in feeding system of ultra precision co-axial grinding machining system. Then, we performed the machining characteristics experiment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.938-941
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• 2005

Recently We make a study of the process expert system model in 2005 process expert system concepts is applied to the digital meister expert system development. Well-designed expert systems imitate the reasoning processes experts use to solve specific problem. Specially, expert systems are used to the engineer in manufacturing industry fur the process control, production management and system management. In this paper, we propose the digital moister expert system fur product design process in manufacturing industry and we present introduction and contents of design process expert system methodology and software far the air purifier design system.