• 동력기계공학회지
• /
• 제13권4호
• /
• pp.68-73
• /
• 2009

The mathematical model has a different response character with the real system because this mathematical model has the modeling errors and the imprecise value of system's parameters. Therefore to find the value of system parameters as possible as near by real value in the model is necessary to design the controlled system. This study concern about the identification method to estimate the parameter for the magnetic bearing system with RCGA(Real Coded Genetic Algorithm). Firstly, we will get the mathematical model from the current amplifier circuit and the magnetic bearing system. Secondly we will get the step response data in this circuit and system. Finally, we will estimate the unknown parameter's value from the data.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제50권12호
• /
• pp.597-603
• /
• 2001

In the mathematical model for the transmission dynamics of HIV infection described in previous papers, the population under consideration is assumed to be homogeneous community of homosexual males for which the parameter x represents the constant rate at which individual members of the population acquire new sexual partners. This is a gross oversimplification since it is well known that individuals vary widely in their levels of sexual activity and in this papers the heterogeneous model is modified to allow for this variation. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by heterogeneous-mixing model. The computer simulation was performed using real date.

• Smart Structures and Systems
• /
• 제14권3호
• /
• pp.367-376
• /
• 2014

Ambient vibration techniques are nowadays a very popular tool to assess dynamic properties of buildings. Due to its non destructive character, this method is particularly valuable, especially for health monitoring of historical monuments. The present ambient vibration experiment consists on the evaluation of vibration modes of a Medieval tower. Situated in Soncino (close to Cremona, in the Northern Italian region named Lombardia), the tower of 41.5 meters height has been monitored by seismometers located at different points inside the structure. Spectral ratios of the recorded ambient vibrations clearly identify a fundamental mode at about 1 Hz, with a slight difference in the two horizontal components. A second mode is also evidenced at approx 4-5 Hz, with a moderate degree of uncertainty. The records of a ML 4.4 earthquake, occurred during the monitoring period, confirm the information obtained by microtremor analysis. Daily variations of both 1st and 2nd mode were detected: these variations, of an amount up to 2%, seem to be well related with the temperature.

• 전자공학회논문지S
• /
• 제34S권11호
• /
• pp.114-125
• /
• 1997

This paper presents a method that automatically recognizes dimension sets from the mechanical drawings, and that classifies 6 types dimension sets according to functional purpose. In the proposed method, the object and closed-loop symbols are separated from the character-free drawings. Then object lines and interpretation lines are vectorized. And, after recognizing dimension sets(consistings of arrowhead, shape line, tail lines, extension lines, text-string, and feature control frame), we classify recognized dimension sets as horizontal, vertical, angular, diametral, radial, and leader dimension sets. Finally the proposed method converts classified dimension sets into AutoCAD data by using AutoLisp language. By using the methods of geometric modeling, the proposed method readily recognized and classifies dimension sets from complex drawings. Experimetnal results are presented, which are obtained by applying the proposed method to drawings drawn in compliance with the KS drafting standard.

• 전자공학회논문지S
• /
• 제34S권10호
• /
• pp.120-131
• /
• 1997

This paper prsents a new method that automatically recognizes the dimension lines (consisting of shape lines, tail lines and extension lines) from the mechanical drawings. In the proposed method, the object and closed-loop symbols are separated from the character-free drawings. Then the object lines and interpretation lines are vectorized by using several techniques such as thinning, line-vectorization, and vector-clustering. Finally, after recognizing arrowheads by using pattern matching, we recognize dimension lines from interpretation lines by using arrohead's directional vector and centroid. By using the methods of geometric modeling and mathematical operation, the proposed method readility recognizes the dimension lines from complex drawings. Experimental resuls are presented, which are obtained by applying the proposed method to drawings drawn in compliance with the KS drafting standard.

• 전자통신동향분석
• /
• 제14권3호통권57호
• /
• pp.1-18
• /
• 1999

본 고에서는 캐릭터 애니메이션을 위한 다면체 모델링 시스템에 대한 기술동향을 분석한다. 이를 위해 다면체 모델링을 지원하는 상용 캐릭터 애니메이션 소프트웨어들에 대한 최신 동향 및 이들 중 현재 고가와 중저가 시장을 주도하고 있는 Alias/Wavefront Maya 1.0 Kinetix 3D Studio Max 2.5를 중심으로 다면체 모델링 기능들을 분석하고 성능평가를 한다. 특히 기능분석에 앞서 두 시스템의 구현 개념을 살펴봄으로써 두 시스템의 다면체 모델링 기능과 더불어 전체적인 성능에 대해서도 분석한다. 이는 다면체 모델링 기능이 단순히 독립되어 구현될 수 있는 것이 아니라 전체 캐릭터 애니메이션 소프트웨어의 구조적인 구성과 밀접한 관련을 가지기 때문이다. 마지막으로 본 고는 두 상용 시스템에 대한 다면체 모델링 기능별 분류 및 그 성능평가에 대해서 벤치마킹 표로 요약. 제시하며 끝을 맺는다.

• 한국멀티미디어학회논문지
• /
• 제11권8호
• /
• pp.1138-1145
• /
• 2008

최근에 다양한 분야에서 캐릭터 표정을 생성하는데 연기자 기반 표정 캡쳐 방법을 널리 사용하고 있다. 특히, 방송이나 게임 등의 분야에서는 실시간 요소와 연기자와 외형상의 차이가 큰 캐릭터의 경우에도 표정 표현이 가능한 다양성이 중요한 문제가 된다. 본 논문에서는 연기자 얼굴에서 캡쳐한 표정을 다양한 얼굴 모델에 적용하는 새로운 표정 애니메이션 방법을 제안한다. 이 방법을 사용하면 최소의 실시간 비용으로 캐릭터 표정을 생성하고 제어하는 것이 가능하다. 본 논문에서는 세 가지 핵심 이슈로서 얼굴 표정 캡쳐, 표정 대입, 표정 애니메이션을 다룬다. 그리고 연기자와 얼굴 모델 간의 특성이 매우 상이한 다양한 경우에 대하여 실험결과를 보여줌으로써 접근방식의 유효성을 증명한다.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송공학회 2009년도 IWAIT
• /
• pp.821-824
• /
• 2009

A method to visualize human body is proposed for various human pose. The method affords three 3D-styles of the same body: firstly, one which wares clothes specified from pattern of dresses, second, body shape, lastly bone structure of body. For this objective, standard body data are prepared which is constructed from CT images. Individual body is measured by 3D body scanner. The present status of our research is limited to offer still images, though we are engaged to accommodate various poses.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.444-449
• /
• 1996

The semiconductor, which is precision product, requires many inspection processes. The surface conditions of the semiconductor chip affect on the functions of the semiconductors. The defects of the chip surface are cracks or voids. As general inspection method requires many inspection procedure, the inspection system which searches immediately and precisely the defects of the semiconductor chip surface is required. We suggest the detection algorithm for inspecting the surface defects of the semiconductor surface. The proposed algorithm first regards the semiconductor surface as random texture and point spread function, and secondly presents the character of texture by linear estimation theorem. This paper assumes that the gray level of each pixel of an image is estimated from a weighted sum of gray levels of its neighbor pixels by linear estimation theorem. The weight coefficients are determined so that the mean square error is minimized. The obtained estimation window(two-dimensional estimation window) characterizes the surface texture of semiconductor and is used to discriminate the defects of semiconductor surface.

• 전력전자학회논문지
• /
• 제17권1호
• /
• pp.57-66
• /
• 2012

This paper proposes a performance improvement of grid-connected inverter system using sliding-mode based direct power control with a variable gain. The proposed control method determine variable gain of PI controller by using modeling at direct power control (DPC) applied to space vector modulation method. Also, this method use sliding-mode control to maintain excellent dynamic response of character of direct power control (DPC). The validity of the proposed algorithm are verified by simulations and experiments.