• 대한기계학회논문집A
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• 제30권5호
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• pp.488-495
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• 2006

The demand for the use of 3D CAD data over the Internet environment has been increased. However, transmission of 3D CAD data has delayed the communication effectiveness because of the CAD data size. Lightweight CAD file design methodology is required for rapid transmission in the distributed environment. In this paper, to derive lightweight CAD files from commercial CAD systems, a file translation system producing a native file is constructed first by using the InterOp and API of the ACIS kernel. Using the B-rep model and mesh data extracted from the native file, the lightweight CAD file with topological information is constructed as a binary file. Since the lightweight CAD file retains topological information, it is applied to the dimensional verification, digital mock-ups and visualization of CAD files. Effectiveness of the proposed lightweight CAD file is confirmed through various case studies.

• 한국기계가공학회지
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• 제11권3호
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• pp.154-159
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• 2012

For numerical analysis of the plate heat exchanger, a lot of time are required in modeling work and calculation. Whereas, this paper was purposed to identify characteristic of the plate heat exchanger through simplification of modeling by interpreting the numerical analysis proximity with the actual model. This study was also examined temperature difference between inlet side and outlet side, inner pressure drop, heat transfer area of plate and change of heat transfer coefficient on the plate depending on the inner corrugation angle and corrugation pitch of a herring bon pattern of the plate heat exchanger among chevron types of the plate exchanger.

• 복식
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• 제25권
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• pp.85-104
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• 1995

The purpose of this study is to suggest the way of reformation of the korean policeman's uniform through the precise investigation and analysis both at home and abroad. The domestic investigation was carried out through the research into the concerned documents on how to emprove the policeman's uniform, the investigation into the focused group interview not only for the policeman but also for policeman's uniform, the analysis on the domestic policeman's service in general and the similar uniforms inside the country. The overseas-research was accomplished by visiting six different countries such as United Kingom, France, Belgium, Italy, Germany and Japan while interviewing and analyzing on their own uniforms respectively. The result of thes survey indicates that Korean Policeman's Uniform is comparatively lacking in dignity, functionability, uniformity and symbolic representation of Korea. In conclusion, this study suggests the way how to improve Korean Policeman's Uniform as follows : 1. To pursue the simplification and the uniformity 2. To give the functionability and flexibility by seasons and functions. 3. To inspire the symbolic character and the dignity of policeman's own.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.341-345
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• 1996

Many mechanical and electrocal systems use the number of motors to make multi degree of freedom motion. One method to reduce the number of motors is suggested by using the 3 D.O.F. motor. The 3 D.O.F. motor has advantages such as downsize, weight reduction, and simplification of the existing 3 D.O.F. systems. In this study, a mathematical model for the 3 D.O.F. motor is suggested and the dynamic equation is derived to analyze the 3 D.O.F. motion. Generallinear control methods are very hard to get the good performance because of the nonlinear terms of each degree of each degree of freedom. To control the motion properly, the nonlinear terms are decoupled using a feedback control law. Nonlinear feedback control law which can arrage the poles arbitrarily is derived. The effects of the gains are examined through computer simulations.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제14권1호
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• pp.33-50
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• 2010

The mathematical thinking which transforms important mathematical content and developed into mathematical structure is a vital process in building up mathematical ability as mathematical knowledge based on structure. Such process based on students' recognition of mathematical concept. Developing mathematical thinking into mathematical structure happens when different cognitive units are connected and compressed to form schema of solution, which could happen through some guided problems. The effort of arithmetic approach in problem solving did not necessarily provide students the structure schema of solution. The using of equation to solve the problem is based on the schema of building equation, and is not necessary recognizing the structure of the solution, as the recognition of structure may be lost in the process of simplification of algebraic expressions, leaving only the final numeric answer of the problem.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.969-974
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• 2003

A simple and cost-effective method for the electrostatic suspension of thin plates like silicon wafers is proposed which is based on a switched voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply that can deliver a dc voltage of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of the relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping origination from the air between the electrodes and levitated object. Using this scheme, a 4-inch silicon wafer was levitated stably with airgap variation decreasing down to 1 $\mu\textrm{m}$ at an airgap of 100 $\mu\textrm{m}$

• 한국정밀공학회지
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• 제25권3호
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• pp.63-72
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• 2008

A new method for the electrostatic suspension of disk-shaped objects is proposed which is based on a time-optimal control scheme and deploys only high-voltage power supplies that can deliver dc voltages of positive and/or negative polarity. This method possesses the unique feature that no high-voltage amplifiers are needed which leads to a remarkable system simplification and objects can be suspended stably even in vacuum environment. Using this scheme, an aluminium disk used in a 3.5-inch HDD was suspended stably at an airgap of 0.3mm.

• 전자공학회논문지
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• 제50권6호
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• pp.260-264
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• 2013

This paper proposes a fast enhancement layer coding method to reduce computational complexity for Scalable HEVC (SHVC) which is based on High Efficiency Video Coding (HEVC). The proposed method decreases encoding time by simplifying Rate Distortion Optimization (RDO)for enhancement layers (EL). The simplification is achieved by restricting CU depths based on the correlation of coding unit (CU) depths between adjacent layers and scalability (spatial or quality) of EL. Comparing with the performance of SHM 1.0 software encoder, the proposed method reduces the encoding time by up to 31.5%.

• 전기전자학회논문지
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• 제3권2호
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• pp.295-304
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• 1999

본 논문에서는 유한체상에서의 다치논리시스템구성을 그래프이론에 기초를 둔 결정도에 의해 구성하는 방법을 제안하였다. 제안한 방법은 먼저 다치논리 Shannon의 확장전개를 토대로 다치논리결정도를 도출하였으며, 부그래프를 적용하여 함수분할을 수행하였다. 그리고 각종 그래프의 동형관계와 정점의 재순서화를 적용하여 결정도의 변수순서선텍알고리즘과 간략화 알고리즘을 제안하였으며 이로부터 최종 다치논리시스템을 설계하는 방법을 제안하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.206-209
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• 1999

Conventional target tracking techniques are primarily based on Kalman filtering or probabilistic data association(PDA). But it is difficult to perform well under a high cluttered tracking environment because of the difficulty of measurement, the problem of mathematical simplification and the difficulty of combined target detection for tracking association problem. This paper deals with an analysis of target tracking problem using fuzzy-logic theory, and determines fuzzy rules used by a fuzzy tracker, and designs the fuzzy tracker by using fuzzy rules and Kalman filtering.