• 한국멀티미디어학회논문지
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• 제16권11호
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• pp.1250-1260
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• 2013

라플라스 피라미드 영상 융합 기반의 대조비 강화기법은 각 자원 영상에서 바람직한 화소를 선택하여 융합할 수 있기 때문에 영상 정보를 충실하게 표현하는 장점이 있다. 하지만 정보 평가를 화소 단위로 수행하기 때문에 영상 잡음에 취약한 문제점을 갖고 있다. 본 논문에서는 영상잡음을 억제하는 개선된 영상 융합기반의 대조비 개선 방법을 제안한다. 제안된 기법은 자원 영상에 대해 블록 기반의 지역적 노출 적절성과 지역적 동질성의 차를 측정하여 이를 기반으로 가중치 맵을 생성하고 라플라스 피라미드를 구축하여 영상을 결합한다. 다양한 영상에 대한 실험을 통해 종래의 기법에 비해 영상 잡음을 배제된 영상을 만들어 낼 수 있음을 보였다.

• Journal of Communications and Networks
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• 제12권2호
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• pp.168-173
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• 2010

Error concealment techniques are significant due to the growing interest in imagery transmission over error-prone channels. This paper presents a spatial error concealment technique for losslessly compressed images using least significant bit (LSB)-based data hiding to reconstruct a close approximation after the loss of image blocks during image transmission. Before transmission, block description information (BDI) is generated by applying quantization following discrete wavelet transform. This is then embedded into the LSB plane of the original image itself at the encoder. At the decoder, this BDI is used to conceal blocks that may have been dropped during the transmission. Although the original image is modified slightly by the message embedding process, no perceptible artifacts are introduced and the visual quality is sufficient for analysis and diagnosis. In comparisons with previous methods at various loss rates, the proposed technique is shown to be promising due to its good performance in the case of a loss of isolated and continuous blocks.

• ETRI Journal
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• 제31권1호
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• pp.21-30
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• 2009

In low bit-rate video transmission, the payload of a single packet can often contain a whole coded frame due to the high compression ratio in both spatial and temporal domains of most modern video coders. Thus, the loss of a single packet not only causes the loss of a whole frame, but also produces error propagation into subsequent frames. In this paper, we propose a novel whole frame error concealment algorithm which reconstructs the first of the subsequent frames instead of the current lost frame to suppress the effects of error propagation. In the proposed algorithm, we impose a constraint which uses side match distortion (SMD) and overlapped region difference (ORD) to estimate motion vectors between the target reconstructed frame and its reference frame. SMD measures the spatial smoothness connection between a block and its neighboring blocks. ORD is defined as the difference between the correlated pixels which are predicted from one reference pixel. Experimental results show that the proposed algorithm effectively suppresses error propagation and significantly outperforms other conventional techniques in terms of both peak signal-to-noise ratio performance and subjective visual quality.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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• pp.171-176
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• 2001

This paper describes the methodology of an IEC 1131-3-based control logic generator for the control system design and converting algorithm between programmable languages. The proposed control logic generator is generated based on the software model and common element with data type, variables, POUs(program organization unit) and execution control unit commonly used within programmable languages of IEC 1131-3 Standard. The generation method of object file was proposed on five programmable language based on IECI 131-3. The generation method of object file is represented as following; 1) the generation method using conversion algorithm from LD to IL with FBD(function block diagram), 2) the generation method using C code generation algorithm from SFC using the SFC execution sequence with FBD and ST(structured text). The proposed control logic generator was implemented by Visual C++ and MFC on MS-windows NT 4.0

• 한국정밀공학회지
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• 제22권8호
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• pp.192-198
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• 2005

In this paper, we propose a new training system for the improvement of equilibrium sense using unstable platform. The equilibrium sense, which provides orientation with respect to gravity, is important to integrate the vision, somatosensory and vestibular function to maintain the equilibrium sense of the human body. In order to improve the equilibrium sense, we developed the software program such as a block game, pingpong game using Visual C++. These training system for the equilibrium sense consists of unstable platform, computer interface and software program. The unstable platform was a simple structure of elliptical-type which included tilt sensor, wireless RF module and the device of power supply. To evaluate the effect of balance training, we measured and evaluated the parameters as the moving time to the target, duration to maintain cursor in the target of screen and the error between sine curve and acquired data. As a results, the moving time to the target and duration to maintain cursor in the target was improved through the repeating training of equilibrium sense. It was concluded that this system was reliable in the evaluation of equilibrium sense. This system might be applied to clinical use as an effective balance training system.

• The Journal of Korean Physical Therapy
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• 제27권3호
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• pp.135-139
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• 2015

Purpose: The aim of this study was to compare EEG topographical maps in patients with chronic stroke after action observation physical training. Methods: Ten subjects were recruited from a medical hospital. Participants observed the action of transferring a small block from one box to another for 6 sessions of 1 minute each, and then performed the observed action for 3 minutes, 6 times. An EEG-based brain mapping system with 32 scalp sites was used to determine cortical reorganization in the regions of interest (ROIs) during observation of movement. The EEG-based brain mapping was comparison in within-group before and after training. ROIs included the primary sensorimotor cortex, premotor cortex, superior parietal lobule, inferior parietal lobule, superior temporal lobe, and visual cortex. EEG data were analyzed with an average log ratio in order to control the variability of the absolute mu power. The mu power log ratio was in within-group comparison with paired t-tests. Results: Participants showed activation prior to the intervention in all of the cerebral cortex, whereas the inferior frontal gyrus, superior frontal gyrus, precentral gyrus, and inferior parietal cortex were selectively activated after the training. There were no differences in mu power between each session. Conclusion: These findings suggest that action observation physical training contributes to attaining brain reorganization and improving brain functionality, as part of rehabilitation and intervention programs.

• 제어로봇시스템학회논문지
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• 제14권5호
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• pp.432-437
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• 2008

This paper proposes a defect cell extraction algorithm for TFT-LCD auto-repair system. Auto defect search algorithm and automatic defect cell extraction method are very important for TFT-LCD auto repair system. In the previous literature[1], we proposed an automatic visual inspection algorithm of TFT-LCD. Based on the inspected information(defect size and defect axis, if defect exists) by the automatic search algorithm, defect cells should be extracted from the input image for the auto repair system. For automatic extraction of defect cells, we used a novel block matching algorithm and a simple filtering process in order to find a given reference point in the LCD cell. The proposed defect cell extraction algorithm can be used in all kinds of TFT-LCD devices by changing a stored template which includes a given reference point. Various experimental results show the effectiveness of the proposed method.

• 전자공학회논문지
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• 제52권9호
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• pp.96-105
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• 2015

본 논문은 비 검출 및 제거 알고리즘의 DSP 최적화 기법을 제안한다. 우리는 카메라 움직임이 있는 환경에서 비 검출 및 제거 기법을 제안하고, 알고리즘 레벨 및 DSP 레벨에서 최적화를 수행한다. 제안하는 기법은 알고리즘 측면에서 기존에 활용하던 라벨링을 블록 단위의 이진 패턴 분석을 통해 오 검출 영역을 제거하는 방식으로 대체하였고 고속 움직임 추정 알고리즘을 이용하여 연산 시간을 개선하였다. DSP 측면에서는 내부 메모리 최적화와 EMDA이용, 소프트웨어 파이프라인 등을 통한 최적화를 통해 임베디드 환경에서 실시간성을 보이며 실험 결과에서는 제안 기법의 성능과 시간 측면의 우수성을 보여준다.

• 한국멀티미디어학회논문지
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• 제13권1호
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• pp.76-82
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• 2010

리버서블 워터마킹은 디지털 영상에 정보를 은닉하고 인증된 상대에게만 은닉된 정보를 복호화하고 원래의 상태로 영상을 복구하는 방법이다. 본 논문에서는 히스토그램 이동을 이용한 고용량 리버서블 워터마킹을 제안한다. 본 논문에서는 높은 삽입량을 위하여 영상을 $2{\times}2$ 블록으로 분할하고, 각 블록에 수평, 수직, 대각에 대한 화소쌍을 이용하여 가장 빈도가 높은 최대 삽입공간을 찾는다. 최대 삽입공간을 포함하는 위치맵을 이용하여 오버플로우와 언더플로우를 제거하여, 반복적인 워터마크 삽입을 통해 삽입량을 증가시킨다. 실험을 통하여 제안한 방법이 기존의 리버서블 워터마킹 방법과 비교하여 좋은 화질과 높은 삽입량을 나타냄을 확인하였다.

• Journal of Korean Neurosurgical Society
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• 제46권2호
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• pp.165-167
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• 2009

Pain caused by chronic pancreatitis is medically intractable and resistant to conventional interventional or surgical treatment. We report a case of spinal cord stimulation (SCS) for intractable pain due to chronic pancreatitis. The patient had a history of nonalcoholic chronic pancreatitis and multiple emergency room visits as well as repeated hospitalization including multiple nerve block and morphine injection for 3 years. We implanted surgical lead at T6-8 level on this patient after successful trial of percutaneous electrode. The patient experienced a decreased visual analog scale (VAS) scores for pain intensity and amount of opioid intake. The patient was followed for more than 14 months with good outcome and no further hospitalization. From our clinical case, spinal cord stimulation on intractable pain due to chronic pancreatitis revealed moderate pain control outcome. We suggest that SCS is an effective, noninvasive treatment option for abdominal visceral pain. Further studies and long term follow-up are needed to fully understand the effect of SCS on abdominal visceral pain.