• Journal of Communications and Networks
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• 제14권2호
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• pp.195-198
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• 2012

An efficient sliding window algorithm employing an adaptive-length guard window for turbo decoders is proposed. The proposed algorithm results in significant complexity reductions, especially for small sliding window lengths where the additional computational complexity required for the guard window is critical.

• Journal of Information Display
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• 제5권4호
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• pp.31-37
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• 2004

In this paper, an effective method for reconstruction of stereoscopic image pair through the regularized adaptive disparity estimation is proposed. Although the conventional adaptive disparity window matching can sharply improve the PSNR of a reconstructed stereo image, but there still exist some problems of overlapping between the matching windows and disallocation of the matching windows, because the size of the matching window tend to changes adaptively in accordance with the magnitude of the feature values. In the proposed method, the problems relating to the conventional adaptive disparity estimation scheme can be solved and the predicted stereo image can be more effectively reconstructed by regularizing the extimated disparity vector with the neighboring disparity vectors. From the experimental results, it is found that the proposed algorithm show improvements the PSNR of the reconstructed right image by about 2.36${\sim}$2.76 dB, on average, compared with that of conventional algorithms.

• 제어로봇시스템학회논문지
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• 제16권8호
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• pp.766-770
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• 2010

In this paper, we present an effective covariance tracking algorithm based on adaptive size changing of tracking window. Recent researches have advocated the use of a covariance matrix of object image features for tracking objects instead of the conventional histogram object models used in popular algorithms. But, according to the general covariance tracking algorithm, it can not deal with the scale changes of the moving objects. The scale of the moving object often changes in various tracking environment and the tracking window(or object kernel) has to be adapted accordingly. In addition, the covariance matrix of moving objects should be adaptively updated considering of the tracking window size. We provide a solution to this problem by segmenting the moving object from the background pixels of the tracking window. Therefore, we can improve the tracking performance of the covariance tracking method. Our several simulations prove the effectiveness of the proposed method.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권5호
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• pp.615-623
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• 2016

The paper describes a hysteretic buck converter including a differentiator and an adaptive hysteresis window controller. Differentiating the feedback signal achieves ultra-fast switching of the buck converter. The adaptive hysteresis window control allows a monotonous operation with predictable noise spectrum, and gives way to efficient design for variable supply and output voltages. The measurement results in a $0.13-{\mu}m$ CMOS process indicated that the switching frequency became double times higher, and the voltage ripple was reduced by up to 69%. They also indicated that the normalized switching frequency variation was reduced by 74% with variable $V_{DD}$ and by 63% with variable $V_{OUT}$. The power efficiency was improved by 3.5% depending on loading condition.

• 대한전자공학회논문지SP
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• 제47권1호
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• pp.97-102
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• 2010

레이저 스펙클이란 간섭성을 가진 레이저 빛을 산란체에 쏘았을 때 반사되는 정보를 레이저 스펙클이라 한다. 이 레이저 스펙클의 가장 큰 특징은 현재 의학 기술로는 볼 수 없는 미세혈관 관찰이 가능하다는 것이다. 미세혈관 관찰을 위해서 레이저 스펙클 장치로 얻은 이미지를 영상처리 하는 과정이 필요하다. 이 논문은 공간적 방향으로 다양한 크기의 윈도우를 적용시키는 새로운 영상처리법을 제안하였다. 기존의 영상처리법 LASCA에서는 고정된 크기의 윈도우를 적용시켜 영상처리 하였다. 하지만 작은 크기의 윈도우를 적용하였을 경우 이미지의 공간 해상도가 좋아 혈관이 잘 보이는 장점이 있지만 스펙클 노이즈의 영향을 많이 받게되는 반면 큰 크기의 윈도우를 적용하였을 경우 노이즈 제거에는 큰 효과를 보지만 해상도가 낮아져 영상이 흐릿해지는 현상을 발견할 수 있다. 그래서 우리는 이 두가지 방법의 장점만 살리는 적응 윈도우 기법을 소개한다. 우리는 적응 윈도우 기법과 기존의 라스카 이미지를 비교하여 보일 것이며 적응 윈도우 기법을 이용해 영상의 화질을 높인 것을 보일 것이다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.77-77
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• 2000

The shape of small or curved object is usually reconstructed using a single camera by moving its lens position to find a sequence of the focused images. Most conventional methods have used a window with fixed shape to test the focus measure, which resulted in a deterioration of accuracy. To solve this problem, this paper proposes a new approach of using a shape adaptive window. It estimates the shape of the object at every step and applies the same shape of window to calculate the focus measure. Focus measure is based on the variance of the pixels inside the window. This paper includes the experimental results.

• 한국멀티미디어학회논문지
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• 제19권2호
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• pp.189-199
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• 2016

Many implantable hearing aids are being developed as alternatives to conventional hearing aids which has inconveniences for use and social stigma that make hearing-impaired people avoid to wear it. Particularly, the fully-implantable middle ear hearing devices (F-IMEHD) are being actively studied for mixed or sensorineural hearing impaired people. In development of F-IMEHD, the most difficult problem is improving the performance of implantable microphone. Recently, Cho et al. have studied the tympanic membrane installed microphone which has better sensitivity and is easier to operate on patient than the microphone implanted under the skin. But, it may cause howling problem due to the feedback signal via oval window and ossicle chain from the transducer on round window in the middle ear cavity, therefore, a feedback canceller is necessary. In this paper, we designed NLMS (normalized least mean square) adaptive feedback canceller for F-IMEHD with tympanic membrane installed microphone and a transducer implemented at round window, and computer simulation was performed to verify its operation. The designed adaptive feedback canceller has a delay filter, a 64 point FIR fixed filter and a 8-tap adaptive FIR filter. Computer simulation of the feedback path is modeled by using the data obtained through human cadaver experiment.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.265-266
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• 1998

This paper describes a depth extraction algorithm in the stereo endoscopic images using adaptive window. First, The relation between the 3D coordinates in the world and the 2D coordinates in the image plane is estimated using camera calibration. Next, stereo matching is performed to find the conjugate pairs in the left and right images. To improve the precision of the matching result, adaptive window which can be varied on the shape as well as on the size according to the area characteristics is used. Finally, the result from the stereo matching and that of camera modeling are combined to extract the real depth information.

• 대한원격탐사학회지
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• 제8권1호
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• pp.15-26
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• 1992

This paper describes an implementation of adaptive stereo matching for DBM generation. The matching method of two stereo satellite images to find corresponding points used in this paper is area-based matching, which is usually used in the field of making DBM. Same window size and search area used as in the conventional matching methods and we propose adaptive stereo matching algorithm in this paper. We cluster three areas which are consist of mountainous areas, cultivated areas and cities, and rivers and lakes by using proposed linear feature extracting method. These classified areas are matched by adaptive window size and search area, but rivers and lakes is excluded in this experiment. The matching time is three times faster than conventional methods.

• 한국지리정보학회지
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• 제10권3호
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• pp.22-30
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• 2007

항공사진을 이용해 산지토사재해 구간의 DTM(Digital Terrain Model)을 제작할 경우 수목이 재해구간을 가리는 경우가 많아 연속적이고 정밀한 DTM을 얻기가 매우 어렵다. 본 연구에서는 이러한 어려움을 해결해 보고자 디지털항공사진을 이용하여 moving window 형태의 필터링방법을 제시하였으며 DTM을 추출하였다. 또한 산지토사재해 구간에서 적정한 필터링의 window 크기에 따른 수목영향제거의 효과를 알아보기 위해 상용 수치사진측량 S/W인 Socet set의 Adaptive 필터링한 DTM과 LiDAR(Light Detection And Ranging)에서 획득한 DTM을 비교하였다. 그 결과 LiDAR에서 획득한 DTM보다는 정확도가 낮았지만 Adaptive 필터링보다는 정확도가 약 6m 정도 높은 결과를 얻을 수 있었다.