• 전기학회논문지
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• 제66권10호
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• pp.1516-1522
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• 2017

We propose a novel monitoring system for diagnosing crack faults of the wind turbine using image information. The proposed method classifies a normal state and a abnormal state for the blade parts of the wind turbine. Specifically, the images are input to the proposed system in various states of wind turbine rotation. according to the blade condition. Then, the video of rotating blades on the wind turbine is divided into several image frames. Motion vectors are estimated using the previous and current images using the motion estimation, and the change of the motion vectors is analyzed according to the blade state. Finally, we determine the final blade state using the Support Vector Machine (SVM) classifier. In SVM, features are constructed using the area information of the blades and the motion vector values. The experimental results showed that the proposed method had high classification performance and its $F_1$ score was 0.9790.

• 인지과학
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• 제22권4호
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• pp.429-447
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• 2011

본 논문에서는 투사성의 원칙을 이용해 결정적 한국어 의존 구문분석을 보완하는 방법을 제안한다. 우리는 결정적 의존 구문분석에 투사성의 원칙을 이용하여 의존 구문분석의 오류를 찾아내고 투사성의 원칙을 만족하도록 수정하여 오류를 개선하였다. 제안하는 모델은 기존의 결정적 의존 구문분석에 비해 높은 정확률을 제공하고 결정적 의존 구문분석의 장점을 유지할 수 있다. 또한 우리는 중간 분석결과를 이용한 자질모델을 제안하였다. 우리는 실험을 통하여 제안한 의존 구문분석 모델이 기존의 의존 구문분석 모델들에 비해 성능이 향상됨을 보였다.

• 대한기계학회논문집A
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• 제33권9호
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• pp.982-989
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• 2009

Parallel Kinematic Mechanism (PKM) is a device to perform the various motion in three-dimensional space and it calls for six degree of freedom. For example, Parallel Kinematic Mechanism is applied to machine tools, medical equipments, MEMS, virtual reality devices and flight motion simulators. Recently, many companies have tried to develop new Parallel Kinematic Mechanism in order to improve the cycle time and the precisional tolerance. Parallel Kinematic Mechanism uses general universal joint and spherical joint, but such joints have accumulated tolerance problems. Therefore, it causes position control problem and dramatically life time reduction. This paper focused on the rolling element to improve sliding precision in new sliding ball joint development. Before the final design and production, it was confirmed that new sliding ball joint held a higher load and a good geometrical structure. FEM analysis showed a favorable agreement with tensile and compressive testing results by universal testing machine. In conclusions, a new sliding ball joint has been developed to solve a problem of accumulated tolerance and verified using tensile and compressive testing as well as FEM analysis.

• Structural Engineering and Mechanics
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• 제3권4호
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• pp.373-382
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• 1995

The weighting strategy has received a great attention and has been widely applied to multicriterion optimization. This gaper examines a global criterion method (GCM) with the weighting objectives strategy in fuzzy structural engineering problems. Fuzziness of those problems are in their design goals, constraints and variables. Most of the constraints are originated from analysis of engineering mechanics. The GCM is verified to be equivalent to fuzzy goal programming via a truss design. Continued and mixed discrete variable spaces are presented and examined using a fuzzy global criterion method (FGCM). In the design process a weighting parameter with fuzzy information is introduced into the design and decision making. We use a uniform machine-tool spindle as an illustrative example in continuous design space. Fuzzy multicriterion optimization in mixed design space is illustrated by the design of mechanical spring stacks. Results show that weighting strategy in FGCM can generate both the best compromise solution and a set of Pareto solutions in fuzzy environment. Weighting technique with fuzziness provides a more relaxed design domain, which increases the satisfying degree of a compromise solution or improves the final design.

• 한국산학기술학회논문지
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• 제1권2호
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• pp.75-83
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• 2000

최근 경제성장 및 국민 생활향상에 따라 폐기물 발생량이 급격하게 증대되어 그 처리문제가 심각해지고 있다. 이러한 폐기물중 노고 포장의 해체 및 유지·보수공사의 증가에 따라 다량 발생하고 있는 폐아스콘은 대부분 재활용되지 못하고 불법처분 또는 매립되고 있어 자원낭비 및 심각한 환경오염 문제를 야기하고 있는 실정이다. 따라서 본 연구에서는 폐아스콘의 재활용을 촉진하기 위하여 이동형 아스팔트 재생기 및 재생첨가제를 사용하여 양질의 신재 아스콘과 동등 수준의 품질을 갖춘 기층용 재생아스콘을 제조하기 위한 기초적 연구를 수행하였다.

• 정보처리학회논문지B
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• 제11B권7호
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• pp.885-892
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• 2004

본 논문에서는 SVM에 기반을 둔 결정법칙에 의해 얼굴인식과 서명인식시스템으로 구성된 다중생체인식시스템을 제안하고자 한다. 이를 위해 퍼지 선형판별기법(Fuzzy Linear Discriminant Analysis : Fnzzy LDA)를 이용한 얼굴인식과 선형판별분석기법과 구간매칭기법을 이용한 서명인식을 구축하였다. 두 개의 단일생체인식시스템을 효과적으로 융합시키기 위해 우선 독립적인 두 개의 생체인식시스템에 의해 산출된 매칭도로부터 등록자(Genuine)와 침입자(Impostor)의 확률 분포 모델을 생성한 후, SVM(Support Vector Machine)에 의해 최종 인증하는 구조로 되어있다. 제안된 방법인 SVM기반 결정법칙을 적용하여 실험한 결과 기존에 결정법칙으로 많이 사용되고 있는 가중치합과 결정트리 방식에 비해 각각 $1.654{\%}$와 $3.3{\%}$의 인식률 향상을 나타내 제안된 방법의 우수성을 나타냈다.

• 한국통신학회논문지
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• 제24권9A호
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• pp.1419-1424
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• 1999

형태학적 필터를 영상 처리 시스템에 효율적으로 구현하기 위하여서는 영상 처리 시스템의 구조적인 제약으로 인하여 형태소의 크기가 작아야 하며, 따라서 크기가 큰 형태소를 가지는 필터의 구현을 위하여 주어진 형태소를 작은 크기의 형태소로 분해하는 과정이 필요하다. 본 논문에서는 임의의 형태학적 필터를 3$\times$3 Pipeline Machine에 효율적으로 구현하기 위하여 모양과 크기에 아무 제한 없이 행태소를 분해하는 알고리즘을 개발한다. 먼저 주어진 형태소를 순차적 방법으로 합집합 분해하고, 각 분해된 결과를 다시 3$\times$3 크기의 형태소로 최적 분해하여 최종 형태소 분해 결과를 얻는다. 개발된 분해 알고리즘을 형태소에 적용하여 분해 결과를 구하였으며, 최적에 매우 근접한 결과를 얻을 수 있었다.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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• pp.402-407
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• 2002

Laminate tooling process is a fast and simple method to make metal tools directly for various molding processes such as injection molding in rapid prototyping field. Metal sheets are usually cut, stacked, aligned and joined with brazing or soldering. Through the joining process, all of the metal sheet layers should be rigidly joined. When joining process parameters are not appropriate, there would be defects in the layers. Among various types of defects, non-bonded gaps of the tool surface are of great importance, because they directly affect the surface quality and dimensional accuracy of the final products. If a laminate tool with defects has to be abandoned, it could lead to great loss of time and cost. Therefore a repair method for non-bonded gaps of the surface is essential and has important meaning for rapid prototyping. In this study, a rapid laminate tooling system composed of a CO2 laser, a furnace, and a milling machine was developed. Metal sheets were joined by furnace brazing, dip soldering and adhesive bonding. Joined laminate tools were machined by a high-speed milling machine to improve surface quality. Also, repair brazing and soldering methods of the laminates using the $CO_2$ laser system have been investigated. ill laser repair process, the beam duration, beam power and beam profile were of great importance, and their effects were simulated by [mite element methods. The simulation results were compared with the experimental ones, and optimal parameters for laser repair process were investigated.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1188-1200
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• 2020

In this paper, we consider a SDMS (Self-Diagnostic Monitoring System) for a reciprocating pump for the purpose of not only diagnosis but also prognosis. We have replaced a multi class estimator that selects only the most probable one with a multi label estimator such that we are able to see the state of each of the components. We have introduced a measure called certainty so that we are able to represent the symptom and its state. We have built a flow loop for a reciprocating pump system and presented some results. With these changes, we are not only able to detect both the dominant symptom as well as others but also to monitor how the degree of severity of each component changes. About the dominant ones, we found that the overall recognition rate of our algorithm is about 99.7% which is slightly better than that of the former SDMS. Also, we are able to see the trend and to make a base to find prognostics to estimate the remaining useful life. With this we hope that we have gone one step closer to the final goal of prognosis of SDMS.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.353-359
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• 1988

In this paper, the design and implementation of a multi-processor based die bonder machine for the semiconductor will be described. This is a final research results carried out for two years from June, 1986 to July, 1988. The mechanical system consists of three subsystems such as bonding head module, wafer feeding module, and lead frame feeding module. The overall control system consists of the following three subsystems each of which employs a 16 bit microprocessor MC 68000 : (i) supervisory control system, (ii) visual recognition / inspection system and (iii) the display system. Specifically, the supervisory control system supervises the whole sequence of die bonder machine, performs a self-diagnostics while it controls the bonding head module according to the prespecified bonding cycle. The vision system recognizes the die to inspect the die quality and deviation / orientation of a die with respect to a reference position, while it controls the wafer feeding module. Finally, the display system performs a character display, image display ans various error messages to communicate with operator. Lead frame feeding module is controlled by this subsystem. It is reported that the proposed control system were applied to an engineering sample and tested in real-time, and the results are sucessful as an engineering sample phase.