• 센서학회지
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• 제18권4호
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• pp.274-279
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• 2009

In this paper, a wide dynamic range active pixel sensor(APS) with output voltage feedback structure has been designed by a 2-poly 4-metal 0.35 $\mu$m standard CMOS technology. We presented a novel APS with output voltage feedback, which exhibits a wide dynamic range. The dynamic range increases at the cost of an additional diode and an additional MOSFET. The output voltage feedback structure enables the control of the output voltage level by itself, as incident light power varies. It is confirmed that the light level which the output voltage level of proposed APS is saturated is about 120,000 lux, which is higher than that of a conventional 3-transistor APS.

• 한국가시화정보학회지
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• 제18권1호
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• pp.50-58
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• 2020

This paper presents flow characteristics of a sweeping jet issued by a feedback-free fluidic oscillator. Overall flow characteristics of feedback-free sweeping jet (FFSJ) were analyzed using flow visualization. The feedback-free sweeping jet has a sinusoidal external flow pattern. The oscillating frequency of the FFSJ is three times higher than that of a conventional sweeping jet at the same Reynolds number. Flow structure and turbulence characteristics were investigated using time-resolved particle image velocimetry (TR-PIV). In instantaneous velocity fields, the flow did not stay at ends but changed the direction continuously in contrast to the conventional sweeping jet. Velocity distributions at each plane which were extracted from mean velocity field has Gaussian distribution, which is similar with a circular jet. The sweep angles were constant as 45° at all Reynolds numbers in the high flow rate regime.

• 방송공학회논문지
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• 제8권1호
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• pp.91-100
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• 2003

본 논문에서는 MPEG-7 영상 디스크립터 중 에지 히스토그램 디스크립터(EHD), 컬러 레이아웃 디스크립터(CLD), 그리고 호모니어스 텍스쳐 디스크립터(HTD)로 구성된 각각의 영상 데이터베이스를 조합하여 렐러번스 피드백을 적용한 영상 검색 방법을 제안한다. 본 논문에서 사용한 에지 히스토그램 디스크립터는 영상의 국부적인 방향성 에지 분포를 표현한 것으로서 영상에 대하여 그 내용물의 형태를 잘 표현하는 디스크립터이다. 컬러 레이아웃 디스크립터는 구조적인 단순함과 빠른 동작 속도에 의해 영상 검색에 넓게 사용되어지며 컬러의 공간적 분포로 표현된다. 호모지니어스 텍스쳐 디스크립터는 영상의 질감에 대하여 정밀한 통계상의 분할로 서술된다. 앞에서 언급한 디스크립터들은 각각의 특징을 반영한 영상 검색에 적용되어 진다. 렐러번스 피드백은 영상 검색에 있어 사용자가 요구하는 정보를 반영할 수 있어 영상의 검색 효율을 높일 수 있다. 제안한 방법은 사용자가 렐러번스 피드백으로 결정한 영상의 특징 정보가 각각의 디스크립터들에 새로운 가중치를 부여한다. 따라서, 사용자의 선택적 요구가 반영된 특징 정보 갱신을 통해 검색 효율을 높인다. 자연 영상에 대한 실험 결과로 제안한 방법이 검색 성능을 향상시켜주는 것을 확인할 수 있다.

• 대한전자공학회논문지SP
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• 제43권1호
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• pp.39-44
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• 2006

본 논문에서는 정지영상에 대해서 borda count 방법을 적용하여 MPEG-7 서술자기반 검색 결과 리스트의 조합에 대한 방법을 제한한다 대부분의 검색 엔진의 경우 MPEG극에서 정의하고 있는 서술자중 하나의 서술자만을 가지고 검색을 수행하고 있다. 이러한 경우 영상의 특성에 따라 검색 성능이 좋을 수도 있지만 그렇지 않을 수도 있다. 따라서 여러 가지 기술자들의 검색 결과를 조합하여 결과 리스트를 작성하는 방법이 요구되고 있다. 이에 따라 본 논문에서는 relevance feedback 알고리즘을 이용한 검색 시스템에 대하여, 여러 가지 서술자에 대한 검색 결과에 대한 결과 리스트를 borda count 방법을 이용하여 각각의 서술자에 의한 검색 결과를 조합하여 하나의 결과 리스트를 작성하는 방법을 제안한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.132.2-132
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• 2001

In this paper, we propose an efficient configuration of a system for the remote control of a mobile robot. The interface has a video feedback and runs in standard web environments. For control servers of mobile robot and CCD camera, we use the environment with embedded web server Specific program has been developed in order to grab the images using Microsoft Visual C++ The external camera sends the video signal to a framegrabber in the PC, then this program grabs the images and puts them in shared memory in BMP format. For a video feedback, we use image feedback based on the client pull technique supported by Netscape and Internet Explorer.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2003년도 추계학술대회
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• pp.213-218
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• 2003

The equipment of industrial robot in manufacturing and assembly lines has rapidly increased. In order to achieve high productivity and flexibility, it becomes very important to develop the visual feedback control system with Off-Line Programming System(OLPS). We can save much efforts and time in adjusting robots to newly defined workcells by using OLPS. A proposed visual calibration scheme is based on position-based visual feedback. The calibration program firstly generates predicted images of objects in an assumed end-effector position. The process to generate predicted images consists of projection to screen-coordinates, visible range test and construction of simple silhouette figures. Then camera images acquired are compared with predicted ones for updating position and orientation data. Computation of error is very simple because the scheme is based on perspective projection which can be also expanded to experimental results. Computation time can be extremely reduced because the proposed method does not require the precise calculation of tree-dimensional object data and image Jacobian.

• 한국항행학회논문지
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• 제13권2호
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• pp.257-261
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• 2009

본 논문은 형태학 이론을 이용하여 이미지의 윤곽선을 추출하는 새로운 방법을 제안한다. 제안된 방법은 분할된 이미지를 형태학 기반의 근접성, 유사성, 연속성을 사용하여 객체들로 그룹화 한다. 즉, 이미지의 시각 계층에서 지각적 방법과 하향식 피드백을 이용하여 이질적인 시각적 형태들을 하나의 시각적 형태로 구체화 시킨다. 실험 결과 다른 방법에 비하여 좋은 성능을 보인다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.520-523
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• 2007

In this paper, we present a novel method to minimize flicker and gray scale errors automatically across the entire panel by using a compensation of the gray levels of image. It was realized by image simulation with feedback structure. As a result of simulation, we observed flickers from the simulated image. And we compensated the gray scale levels for original image. The compensated gray scale levels correspond to flickers which are generated by difference of pixel voltage in odd and even frame. And we simulated repetitively the compensated image by our block diagram for reduction flicker. Consequently, we confirmed flickers have been decreased more than 87%. Furthermore, our method provides visualization and valid prediction for improvement of TFT-LCD panel

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2006년도 추계학술발표대회
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• pp.19-22
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• 2006

In this paper we present a vision based place recognition method which uses Bayesian method with feed back of image retrieval. Both Bayesian method and image retrieval method are based on interest features that are invariant to many image transformations. The interest features are detected using Harris-Laplacian detector and then descriptors are generated from the image patches centered at the features' position in the same manner of SIFT. The Bayesian method contains two stages: learning and recognition. The image retrieval result is fed back to the Bayesian recognition to achieve robust and confidence. The experimental results show the effectiveness of our method.

• The Journal of Korean Physical Therapy
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• 제29권5호
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• pp.246-254
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• 2017

Purpose: Previous studies have reported that action observation training has beneficial effects on enhancing the motor task, such as balance and gait functions. On the other hand, there have been few studies combined with action observation training and auditory feedback. The purpose of this study was to determine the effects of action observation training with auditory feedback on the gait function in stroke patients with hemiparesis Methods: A total of 24 inpatients with post-stroke hemiparesis were assigned randomly to either an experimental group 1 (EG 1, n=8), experiment group 2 (EG 2, n=8), control group (CG, n=8, EG 1). The EG 2 and CG watched video clip demonstrating three functional walking tasks with auditory feedback, without auditory feedback, and showing a landscape image, respectively. The exercise program consisted of 30 minutes, five times a week, for four weeks. The participants were measured to 10MWT (10 m walk test), 6MWT (6 minutes walking distance test), TUG (timed up and go test), DGI (dynamic gait index), time and steps of F8WT (figure-of-8 walk test). Results: In the intra-group comparison after the intervention, EG 1 and EG 2 showed a significantly different gait function (10MWT, 6MWT, DGI, TUG, F8WT) (p<0.05). In the inter-group comparison after intervention, EG 1 showed significant improvements in the entire gait parameters and EG 2 only showed significant improvement in DGI and TUG compared to CG (p<0.05). Conclusion: These findings show that action observation training with auditory feedback may be used beneficially for improving the gait function of stroke patients with hemiparesis.