• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1626-1629
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• 2003

The study is expressed on the web browser using virtual reality of developer manufacturing process and method or manufactured goods conviction for designer and developer with visualized model. This study purpose of basic feature with VRML file and Java and VRML with AWT to get WC code was presented. The study process is equal to the real thing modeling on using Pro/Engineer and exports on the VRML1.0. The condition converts VRML1.0 to VRML2.0 on the CROSS ROADS. And then Cosmo World is coding and manufacturing simulation is expressed on the Cosmo Player.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.1
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• pp.98-105
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• 2008

In this paper, the system for monitoring process of aluminum laser welding was developed using the light signal emitted from the plasma which comes from interaction between material and laser. Photodiode for monitoring system was selected based on the spectrum analysis of light from plasma and keyhole. Behavior of plasma and keyhole was analyzed through the sensor signals. Value of sensor signal represented the light intensity and fluctuation of signal indicated the stability of plasma and keyhole. For the relation between welding condition and sensor signals, the input power and weld geometry greatly effected on the average of each sensor signals. Using the feature values of signals, estimation model for tensile strength of weld was formulated with neural network algorithm. Performance of this model was verified through coefficient of determination and average error rate.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.84-87
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• 1999

This paper presents a preform design method that combines the analytic method and inference of known knowledge with neural network. The analytic method is a finite element method that is used to simulate backward extrusion with pre-defined process parameters. The multi-layer network and back-propagation algorithm are utilized to learn the training examples from the simulation results. The design procedures are utilized to learn the training examples from the simulation results. The design procedures are two methods the first the neural network infer the deformed shape from the pre-defined processes parameters. The other the network infer the processes parameters from deformed shape. Especially the latest method is very useful to design the preform From the desired feature it is possible to determine the processes parameters such as friction stroke and tooling geometry. The proposed method is useful for shop floor to decide the processes parameters and preform shapes for producing sound product.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.2000-2003
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• 2003

This paper presents a three-dimensional (3D) head pose estimation algorithm for robust face recognition. Given a 3D input image, we automatically extract several important 3D facial feature points based on the facial geometry. To estimate 3D head pose accurately, we propose an Error Compensated-SVD (EC-SVD) algorithm. We estimate the initial 3D head pose of an input image using Singular Value Decomposition (SVD) method, and then perform a Pose refinement procedure in the normalized face space to compensate for the error for each axis. Experimental results show that the proposed method is capable of estimating pose accurately, therefore suitable for 3D face recognition.

• MALSORI
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• no.29_30
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• pp.95-104
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• 1995

최근 음운론에서 lateral 자질이 자질수형도에서 어디에 위치하는가에 대해 두 가지 접근이 있어 왔다. Levin(1988)은 lateral이 coronal에만 나타나는 제약에 기초해서, lateral 자질이 coronal 마디의 의존자질이라고 주장한다. 이에 반해 Rice & Avery(1991), 그리고 Shaw(1991)는 lateral 자질이 자질수형도의 위쪽에 위치한다고 주장한다. 이 두 이론을 비교하기 위해 본 논문에서는 다음과 같은 내용의 음운론적인 요소들과 음성학적인 요소들을 고려한다. 첫째, 음성학에서 lateral의 기능은 lateral이 일반적으로 수형도 위쪽에 위치하는 것으로 간주되는 조음방법 자질이라는 것을 시사한다. 둘째, Papuan 언어군에서 보고된 Velar lateral의 존재는 lateral이 coronal에만 나타난다는 제약을 무효화하면서 Levin이론의 전제를 의심스럽게 한다. 셋째, 몇 가지 다른 유형의 동화 현상에 대한 논의는 동화현상이 lateral이 수형도의 위쪽에 위치하는 이론에서 더 잘 설명된다는 것을 보여 준다. 마지막으로 Chumash와 Tahltan의 coronal harmony에서 나타나는 lateral의 transparency와 Cambodian과 Javanese에서 나타나는 OCP효과 따위도 lateral이 조음위치 마디의 의존 자질인 이론에서는 설명될 수 없는 underspecified lateral의 증거를 제시한다. 이와 같은 논의에 기초해서 본 논문의 결과는 lateral이 수형도 위쪽에 위치한다는 주장이 옳음을 보여준다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.1076-1082
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• 2003

As functional requirement of massive digital information storage devices are on a trend for the higher data transfer rate and lower cost, many different technical efforts are being tested and implemented in the industry. FDB(Fluid Dynamic Soaring) is one of the major breakthroughs in rotor design in terms of TMR budget. Although FDB analysis based on Reynolds' equation is well established and popularly being used for DB design especially for the estimation of bearing stiffness, there are obvious limitations in the approach due to the inherent assumptions. A generalized analysis tool employing the full Navier-Stokes equation and the energy balance is to be beneficial for detailed FDB design In this publication, an efficient geometry modeling method is presented that provides fully integrated inputs for general FVM/FDM codes. By virtue of the flexibility of the presented method, many different detailed FDB design and analysis are carried over with ease.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.405-410
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• 2004

2-dimensional impeller's distinctive feature is expected to have an influence on performance and flow characteristics of centrifugal compressor. And new design method is required for 2-dimensional impeller, because the unique geometry cannot be designed using conventional theories. The objective of this study is to advance new design technology for 2-dimensional impeller and to investigate the performance characteristics of designed 2-dimensional centrifugal compressor. The performance test for 2-dimensional impeller is conducted at 35000, 40000 and 45000rpm. Also numerical calculation is applied by using commercial CFD code, FLUENT, and the results are compared with experimental results.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.898-900
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• 2004

3차원 모델은 흔히 비정규(irregular connectivity) 삼각형 메쉬로 구성된다. 비정규 메쉬를 정규(completely-regular connectivity) 메쉬로 재생성라면 기하 정보를 정규적인 연결성에 상응하는 2차원 형태의 이미지로 나타낼 수 있다. 본 논문은 매개변수(parameter) 영역에서 비정규 메쉬의 특징점들로 연결된 날카로운 모서리(sharp edge)로의 특징 snapping 을 통하여 기존의 방법으로 생성된 기하 이미지보다 특징이 잘 보호된 기하 이미지 생성에 대한 방법을 제시한다. 우선 비정규 메쉬를 구성하는 정점들의 곡률을 계산한 후 매개변수 영역에서 곡률이 증가하는 방향으로 snapping을 적용하였다. 실험 결과, 본 논문에서 제시한 방법이 기존의 방법에 비해 비정규 메쉬의 특징을 보다 잘 보호할 수 있음을 확인하였다.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.601-604
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• 2005

본 논문에서는 전방향 등극기하를 이용하여 이동로봇의 효과적인 표식대응에 대하여 기술한다. 전방향 영상에서 등극점과 등극선의 특성에 따라 추출된 특징의 영상내 위치를 추정한다. 예측된 특징의 영상위치정보를 통해 효과적인 특징 대응을 하며 본 연구에서는 두영상에서 8개의 대응점을 이용하여 기초행렬 F를 구하고 이것으로 특징의 공간정보를 계산한다. 따라서 기초행렬 F에서 계산된 기초행렬 E로부터 로봇은 자신의 위치와 운동정보(회전, 병진운동)를 알 수 있다. 또한 효과적인 특징대응을 위해 탐색범위를 축소함으로써 계산시간의 단축과 강인한 특징대응을 제시하였다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.04a
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• pp.182-189
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• 1996

The focus of this study is on the problem of the design of structure of undetermined topology. This problem has been regarded as being the most challenging of structural optimization problems, because of the difficulty of allowing topology to change. Conventional approaches break down when element sizes approach to zero, due to stiffness matrix singularity. In this study, a novel nonlinear Programming formulation of the topology Problem is developed and examined. Its main feature is the ability to account for topology variation through zero element sizes. Stiffness matrix singularity is avoided by embedding the equilibrium equations as equality constraints in the optimization problem. Although the formulation is general, two dimensional plane elasticity examples are presented. The design problem is to find minimum weight of a plane structure of fixed geometry but variable topology, subject to constraints on stress and displacement. Variables are thicknesses of finite elements, and are permitted to assume zero sizes. The examples demonstrate that the formulation is effective for finding at least a locally minimal weight.