• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.303-305
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• 2011

2010년 여름철 만리포의 수질은 COD가 지속적으로 2.0 mg/l 이하로 측정되어 양호한 상태였고 SS(부유물질)의 량이 7월 조사에서 30mg/l를 초과하였으나 해수욕에는 무리가 없었을 것으로 판단된다. 식물플랑크톤은 대발생이나 적조 등의 현상이 나타나지 않았다. 대천의 수질은 8월 조사에서 COD값이 평균 2.0mg/l를 초과하기도 하였으나 하절기 정반적으로는 2.0mg/l 이하로 나타나 역시 해수욕장 수질로서는 양호하다. 식물플랑크톤 역시 규조류가 우점하는 보편적인 해수의 특징을 보였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.113-114
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• 2010

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.8
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• pp.727-733
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• 2010

Optical tables provide a platform for the establishment and test of measurement systems which use Laser. Therefore, not only static characteristics such as surface flatness, static stiffness and etc. but dynamic response characteristics is very important design parameter. The dynamic stiffness is generally estimated through the modal test, and compliance is used as a representative performance standard. Recently there is an example of defining the dynamic deflection coefficient and using it as a new performance standard of the dynamic stiffness, but it is not generalized yet in industry. In this study, we verify the validity of existing DDC calculus by making an experiment on granite. And for improvement in damping performance of optical tables, we are going to evaluate the effect of fillers on the compliance, then develop an epoxy adhesive based on the result of this experiment.

• IE interfaces
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• v.12 no.4
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• pp.586-594
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• 1999

This paper introduces a production scheduling system for the block assembly shop in a shipbuilding company. We are to make a schedule for the assembly shop and related subassembly production shop. The objectives of the scheduling system are balancing of the workload of the subassembly shops as well as the assembly shop. There are a number of technological and resource constraints including assembly space restriction which is most important and critical resource in the shop. It is very hard and time consuming to consider the two problems, the workload balancing and the spatial allocation problem, simultaneously, and hence, we analyze the two problems independently. The first problem has already been introduced(고시근, 1996), and the overall appearance of the system and the spatial allocation algorithm are presented in this paper.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2001.10a
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• pp.283-285
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• 2001

The most work-space invest much time and labor for optimal arrangement. The work-plates of the work-space should be arranged, processed and assembled under the restricted work space. The optimal arrangement under the terms of a restriction arrange the maximum work-plates in appointed work-space. It's the central aim. The work-plates arrangement scheduling of the most work-space are achieved through the experience of the planner. Like this, if the work-plates arrangement is worked by hand, there spend much time for the training planner. And the burden of the personnel expenses occur for using the master worker, also there are dangerous factors to be able to bring the bottleneck circumstance for the process planning, because the quick work planning does not accomplish. With such problems, the biggest problem is inferior the value of the plan. For solved the such problem of hand-operating, some work-spaces developed and used the work-plate arrangement scheduling system for the special quality of themselves. This paper make research into a plan to develop the work-plate arrangement scheduling system efficiently.

• Journal of Welding and Joining
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• v.17 no.5
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• pp.55-60
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• 1999

In thin plate welding, welding deformation is deformation is produced in special form like buckling distortion, which is different from one in thick plate welding, large quantitatively, and has complicated form. Therefore, a particular countermeasure to prevent the welding deformation in manufacturing process is requested. Otherwise it takes more time to straighten the welding deformation than to fabricated a steel structure newly and in case of failing to straighten the welding deformation in beginning of the flame straightening process, even if the flame straitening is completed, the appearances is not good and sometimes eve refabrication is needed. To minimize these problems. In this present paper, the effects of the condition of support pin on out-of plane deformation produced by thin plate Butt welding in investigated through experiment and the countermeasure to prevent the welding deformation in suggested.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.33-33
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• 2004

래핑은 상하정반 사이에 공작물과 공작물을 지지할 수 있는 캐리어를 삽입하여 유성치차운동 방식으로 가공하는 것으로, 오래 전부터 산업전반에 걸쳐 널리 사용되어 왔다. 래핑의 특징은 한번에 많은 수의 공작물을 가공할 수 있어 가공능률이 우수하고, 높은 형상 정밀도를 확보할 수 있을 뿐만 아니라 가공부의 표면 거칠기가 양호하고 가공 변질층이 작다는 이점을 가지고 있다. 특히 박판 형상의 가공물이나 경도에 비해 강도가 취약한 경취성 재질의 가공물을 정밀하고 효과적으로 가공할 수 있기 때문에 최근에는 정밀 기계산업 분야 이외에도 광통신 산업, 반도체 산업, 디스플레이 산업 등에서 그 활용이 점차 증가하고 있는 추세이다.(중략)

• Special Issue of the Society of Naval Architects of Korea
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• 2005.06a
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• pp.159-164
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• 2005

In this paper, we study some problems of the scheduling on the fixed area in a shipbuilding. The scheduling, constrainted a working area, is not easy to make a load balance and to operate a change of daily work plan. we proposed a block arrangement algorithm to make the load balance and developed a system used to operate the change of daily work plan.

• Special Issue of the Society of Naval Architects of Korea
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• 2007.09a
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• pp.79-88
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• 2007

In this study, we improved the layout of deckhouse pre-erection area where erects the blocks and developed the pre-erection block arrangement system for the improvement of productivity and effectiveness. The major operating point of the pre-erection area is to fabricate as many as possible that has restrict area and working plate. The developed system has information management module, scheduling module, schedule control module, statistics module, and information integrate module. The heuristic algorithm is issued and evaluated with real data. And genetic algorithm is used for the evaluation of issued it.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.61-61
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• 2003

CMP(Chemical Mechanical Polishing)는 VLSI의 제조공정에서 실리콘웨이퍼의 절연막내에 있는 토포그래피를 제어할 수 있는 광역 평탄화 기술이다. 또한 최근에는 실리콘웨이퍼의 나노토포그래피(Nanotopography)가 STI의 CMP 공정에서 연마 후 필름의 막 두께 변화에 많은 영향을 미치게 됨으로 중요한 요인으로 대두되고 있다. STI CMP에 사용되는 CeO$_2$ 슬러리에서 첨가되는 계면활성제의 농도에 따라서 나노토포그래피에 미치는 영향을 제어하는 것이 필수적 과제로 등장하고 있다. 본 연구에서는 STI CMP 공정에서 사용되는 CeO$_2$ 슬러리에서 계면활성제의 농도에 따른 나노토포그래피의 의존성에 대해서 연구하였다. 실험은 8 "단면연마 실리콘웨이퍼로 PETEOS 7000$\AA$이 증착 된 것을 사용하였으며, 연마 시간에 따른 나노토포그래피 의존성을 알아보기 위해 연마 깊이는 3000$\AA$으로 일정하게 맞췄다. 그리고 CMP 공정은 Strasbaugh 6EC를 사용하였으며, 패드는 IC1000/SUBA4(Rodel)이다. 그리고 연마시 적용된 압력은 4psi(Pounds per Square Inch), 헤드와 정반(table)의 회전속도는 각각 70rpm이다 슬러리는 A, B 모두 CeO$_2$ 슬러리로 입자크기가 다른 것을 사용하였고, 농도를 달리한 계면활성제가 첨가되었다. CMP 전 후 웨이퍼의 막 두께 측정은 Nanospec 180(Nanometrics)과 spectroscopic ellipsometer (MOSS-ES4G, SOPRA)가 사용되었다.