• 인지과학
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• 제25권3호
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• pp.259-276
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• 2014

마르셀 뒤샹이나 지아코모 발라와 같은 미래파 화가들은 물체가 움직이는 순간 순간의 정지 이미지를 캔버스에 중첩해서 운동감을 표현하려고 했다. 본 연구진은 선행 연구에서 이렇듯 운동성이 내포된 추상 미술작품들에 대한 사전 경험이 뇌의 운동 지각 영역의 반응에 영향을 미친다는 것을 보고한 바 있다. 본 연구에서는 선행 연구에서 관찰된 사전 경험에 따른 차별적인 뇌 운동 지각 영역의 활성화가 안구 운동 패턴의 차별성에 기인하는지 살펴보았다. 사전 경험은 미술 전공 여부로 조작하였다. 또한 전문성 이외에도 움직임 내포에 관한 화가의 의도 자각 여부에 따라 관찰자의 안구 운동 패턴에 차이가 나타나는지 검증해보고자 하였다. 연구 결과, 미술 전공 여부에 따라 추상화 지각시 그림 전체에 대한 시선고정 횟수나 시간 등에 차별적인 경향이 나타났다. 화가의 표현 의도에 대한 자각은 이러한 전반적인 차이와 관련이 없었다. 반면, 운동성의 내포라는 화가의 표현 의도의 자각은 추상화 중 운동성이 표현된 특정 위치에 대한 안구운동과 연관성을 보였다. 즉, 표현의도를 자각한 관찰자들은 그렇지 못한 관찰자들에 비해 추상화 중 움직임과 연관된 신체 부위가 표현된 위치에 좀 더 집중하는 경향을 나타냈으며, 화폭에 표현된 물체의 움직임 방향과 합치하는 방향의 안구 운동을 더 많이 보였다. 미술 전공 여부는 움직임 표현 위치에 특정적인 안구 운동과 무관하였다. 이러한 결과는 미술 전문성 및 화가의 의도 자각 여부가 관찰자들이 움직임이 함축된 추상화를 지각하는 방식에 차별적으로 관여함을 시사한다. 즉, 전문성은 그림에 대한 전반적인 지각 방식에, 내포된 움직임에 대한 자각은 그 정보에 특정적인 공간에 대한 지각방식에 관여할 가능성을 제안한다.

• 제어로봇시스템학회논문지
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• 제17권11호
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• pp.1138-1144
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• 2011

This article deals with the problem of fault detection of a spacecraft's actuators. The authors introduce an extended unknown input observer for nonlinear systems. This is an extended form of unknown input observers which are used for linear systems. Since faults are not available, those are considered as unknown inputs. Unknown input observers can estimate states without full information of inputs if some conditions are satisfied. The authors suggest a continuous-time extended UIO (eUIO) and prove the convergence of state estimation errors. Since the dynamic equation of a spacecraft is nonlinear, an extended UIO can be applied. Three eUIOs are designed to monitor three reaction wheels. The moving averages of each eUIO's residuals are selected for decision logic. The proposed method is verified by numerical simulations.

• 제어로봇시스템학회논문지
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• 제10권7호
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• pp.575-582
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• 2004

The observer design problem is studied for a class of multi-output nonlinear systems that are not necessarily observable. Generalized nonlinear observer canonical form is introduced for multi-output nonlinear systems to design nonlinear observers. Sufficient conditions are given for a nonlinear system to be transformed by state-space change of coordinates into generalized nonlinear observer canonical form. Based on this canonical from, a sufficient condition is also given for the existence of nonlinear observers. An illustrative example is presented to show the design procedure of the proposed method.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1365-1370
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• 2004

In this paper, a novel anti-sway control system that uses an inclinometer as a sway sensor is investigated. The inclinometer, when compared with a vision system, is very cheap, durable, and its maintenance is easy. However, it gives almost the same performance. Various observers for estimating the angular velocity of the load and the trolley velocity are presented. A state feedback controller with an integrator is designed. After a time-scale analysis, a 1/4-size pilot crane of the rail-mounted quayside crane is constructed. The performance of the proposed control system was verified with a real rubber-tired gantry crane at a container terminal as well as with the pilot crane constructed. Experimental results are provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.366-370
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• 1990

Generally, when servo system is used, various sensors are required to have comparison and compensation to the reference value. However, the sensors are relatively expensive, and cannot be always implemented because of the limit of space or the environmental conditions. In this paper, state observer systems without sensors are investigated. State observer systems are required to estimate the states quickly and exactly without being affected by the disturbances. Thus, in this paper, the effects of systems poles and observer poles are studies. In addition, the parameter variations are also considered to evaluate the effect of them to the observer based systems. Also, in this paper a whole system which includes compensators, observers and loads are considered and analysed by using numerical simulations.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 추계학술대회 논문집
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• pp.7-10
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• 2001

To obtain a high performance in a direct vector controlled induction machine, it is essential to correct estimation of rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper presents an analysis method for conventional flux observers using Parameter Sensitivity. The Parameter sensitivity is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated flux as the transfer function, and analyzed a parameter sensitivity of this transfer function.

• 한국의류학회지
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• 제24권8호
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• pp.1177-1186
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• 2000

The Study was consist of clothing shape(H-line, A-line, V-line, X-line, O-line) and color(Blace, Grey1, Grey2, White). The main purpose of this study is to analyze image differences due to shape variation, image differences due to observers characteristic differences. The main findings can be summarized as follow. First, image differences due to shape variation are statistically significant ar five factors - the maturity level, the degree of softness, attractiveness, the degree of recognition, and the activity. But the degree of recognition is found out to be the least significant factor. H-line is estimated the mature image, A·X-line is estimated young, feminine and active image. Second, image differences by observers characteristics are various depending on the shape of clothing.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.437-441
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• 1999

본 논문에서는 미지입력 외란에 대해서 강인한 새로운 형태의 고장 진단법을 제안한다. 시스템에 구동기만의 고장이 있는 경우는 한 개의 Luenberger 형태의 미지입력 PI 관측기의 설계에 의해 관측 적분 오차를 이용함으로서 구동기의 고장진단이 가능하고, 완벽한 분리가 이루어짐을 보이며, 복합적인 구동기 및 센서의 고장의 경우에는 다중 미지입력 PI 관측기를 출력의 개수만큼 설계함으로서 완벽한 고장진단 및 분리가 이루어짐을 제안한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1176-1178
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• 2001

To obtain a high performance in a direct vector controlled induction machine, it is essential to correct estimation of rotor flux. The accuracy of flux observers for induction machines inherently depends on parameter sensitivity. This paper presents an analysis method for conventional flux observers using parameter Sensitivity. The Parameter sensitivity is defined as the ratio of the percentage change in the system transfer function to the percentage change of the parameter variation. We define the ratio between real flux and estimated flux as the transfer function, and analyzed a parameter sensitivity of this transfer function.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.589-594
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• 1993

This paper presents a fault detection strategy that discriminates the faulty sensor and that detects the component fault using a bank of observers for the system in which sensor fault and component fault can occur simultaneously. Observers as many as the number of measurements are designed, and each observer uses measurements excluding sequentially one measurement, to estimate the state variables. The faulty sensor can be found out by comparing each state variable from different observer. Next, component fault can be detected by using measurements from the sensors excluding the faulty sensor. The suggested strategy is applied to a nonisothermal, series reaction with unknown reaction kinetics in a CSTR. This strategy is found out to perform well even in the case that the sensor and component fault occur simultaneously. Since each observer is designed to be independent of reaction kinetics, this strategy is not affected by the model uncertainty and nonlinearity of the reaction kinetics.