• 제목/요약/키워드: Median

검색결과 6,064건 처리시간 0.027초

근피로 중앙주파수를 위한 AR모델의 차수결정에 관한 연구 (A Study on Order Decision of AR Model for Median Frequency in Fatiguing EMG)

  • 조은석;차샘;이기영
    • 한국정보전자통신기술학회논문지
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    • 제3권1호
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    • pp.8-12
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    • 2010
  • 본 연구에서는 t-test와 ANOVA를 이용하여 근전도의 중앙주파수 추출을 위한 AR모델 차수결정 및 중앙주파수 비교에 관한 연구이다. 근전도의 근피로와 관계된 특징인자인 영교차율 및 저대역에너지, 중앙주파수를 추출하여 근피로에 이를 때까지의 변화를 평가해 봄으로써 근피로 정도나 시점까지의 변화 정도를 비교 및 고찰하였다.

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Edge Preserving Speckle Reduction of Ultrasound Image with Morphological Adaptive Median Filtering

  • Ryu, Kwang-Ryol;Jung, Eun-Suk
    • Journal of information and communication convergence engineering
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    • 제7권4호
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    • pp.535-538
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    • 2009
  • Speckle noise reduction for ultrasound CT image using morphological adaptive median filtering based on edge preservation is presented in this paper. Speckle noise is multiplicative feature and causes ultrasound image to degrade widely from transducer. An input image is classified into edge region and homogeneous region in preprocessing. The speckle is reduced by morphological operation on the 2D gray scale by using convolution and correlation, and edges are preserved. The adaptive median is processed to reduce an impulse noise to preserve edges. As the result, MAM of the proposed method enhances the image to about 10% in comparison with Winner filter by Edge Preservation Index and PSNR, and 10% to only adaptive median filtering.

Order Statistic-Median Hybrid(OMH)필터 (Order Statistic-Median Hybrid(OMH) Filter)

  • 백수현;황유모;류동기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1992년도 하계학술대회 논문집 A
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    • pp.434-436
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    • 1992
  • In this paper, we propose a new multilevel nonlinear filter for simultaneous edge detection and noise suppression, which we call a order statistic-median hybrid(OMH) filler. The median-related filters cause an edge shift in the presence of an impulse near the edge. The proposed filter reduces such edge shifting while suppressing impulsive as well as nonimpulsive noise. We show that at the noisy edge point the OMH filter is substantially superior to the median filter, the $\alpha$-TM filter and the STM filter[I] in two respects: (a) the output bias error and (b) the output mean square error. Test results confirm that the OMH filter is robust in preserving sharp edges, inhibiting edge shifting, and suppressing a wide variety of noise. The structure for the OMH filter integrated circuit is also described.

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Group Technology Cell Formation Using Production Data-based P-median Model

  • 원유경
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회/대한산업공학회 2003년도 춘계공동학술대회
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    • pp.375-380
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    • 2003
  • This study is concerned with the machine part grouping m cellular manufacturing. To group machines into the set of machine cells and parts into the set of part families, new p-median model considering the production data such as the operation sequences and production volumes for parts is proposed. Unlike existing p-median models relying on the classical binary part-machine incidence matrix which does not reflect the real production factors which seriously impact on machine-part grouping, the proposed p-median model reflects the production factors by adopting the new similarity coefficient based on the production data-based part-machine incidence matrix of which each non-binary entry indicates actual intra-cell or inter-cell flows to or from machines by parts. Computation test compares the proposed p median model favorably.

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정중 흉골 절개술을 통한 양측의 기종성 폐포의 절제 (Median Sterontomy for Bilateral Resection of Emphysematous Bullae)

  • 이성윤
    • Journal of Chest Surgery
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    • 제23권4호
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    • pp.720-730
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    • 1990
  • The complicated pulmonary emphysema including “Giant bullae” and spontaneous pneumothorax often involve both lungs, and controversy exists concerning which is the more rational means of surgical treatment-bilateral simultaneous operation or two staged operation. We report three cases of the complicated bilateral bullous emphysema and two cases of bilateral spontaneous pneumothorax treated through median sternotomy. We performed the ligation of bullae, bullectomy, cystectomy, wedge resection, and left lower lobectomy through median sternotomy. No technical problems were encountered through this approach, which provided maximum benefit with one operation In conclusions, median sternotomy may be appropriate for resection of emphysematous bullae, specially in a severe COPD patient who may be poorly tolerated the superimposed loss of respiratory function due to incisional pain, because median sternotomy permit bilateral exploration, minimal impairment of pulmonary function, simultaneous restoration of pulmonary function, less incisional pain than routine lateral thoracotomy.

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Application of Modified Median Filter for Grading Produce

  • Morio, Yoshinari;Ikeda, Yoshio
    • 한국농업기계학회:학술대회논문집
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    • 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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    • pp.842-851
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    • 1996
  • Median filter(MF) has often been applied to color or gray images as a noise fiilter in image processing . Application of MF to binary images was tried in this study. For binary images, MF not only can remove noise but can also work as an indicator showing the dominant color in a region which is called window . Fro example, MF can be used to categorize clusters and to detect interested parts of an object. In other words, MF can also be used to remove unnecessary parts. The function of MF can be intensified by introducing a thresholding value, which is determined by the size of the interested part of an object. This improved MF for binary images is called the modified median filter(MMF), and its applicability to grade produce will be discussed in this paper.

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A Comparison of the performance of mean, median, and precedence control charts for nonnormal data

  • Kim, Jung-Hee;Lee, Sung-Im;Park, Heon-Jin;Lee, Jae-Cheol;Jang, Young-Chul
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2005년도 춘계 학술발표회 논문집
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    • pp.197-201
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    • 2005
  • In this article, we will compare the performance of the mean control chart, the median control chart, the transformed mean control chart, the transformed median control chart, and the precedence control chart by simulation study. For control charts with transformed data, Yeo-Johnson transformation is used. Under the in-control condition, ARL's in all control charts coincide with the designed ARL in the normal distribution, but in the other distributions, only the precedence control chart provides the in-control ARL as designed. Under the out-of-control condition, the mean control chart is preferred in the normal distribution and the median control chart is preferred in the heavy-tailed distribution and the precedence control chart outperforms in the short-tailed distribution.

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주행차량에 의한 중앙분리대 유도풍의 풍력발전 활용 가능성 (Possibility of Wind Power Generation by a Vehicle-Induced Wind at the Median Strip on Hightway)

  • 우상우;김현구;장문석;신형기
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2008년도 추계학술대회 논문집
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    • pp.315-317
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    • 2008
  • The purpose of this study is to confirm the possibility of wind power generation by a vehicle-induced at the median strip on highway. In order to find out wind field information, a CFD method was used. According to the simulation results, the x, y, z-component of the wind velocity around a median strip are rapidly changed at near before and behind a moving vehicle. The x-component of the wind velocity appears high within the range of the length of the passing vehicle, and the wind direction appeared in the opposite direction at the behind of a vehicle. However, x and y-components of the wind velocity at the behind of vehicle are shown constantly. We confirmed possibility of wind power generation using a vehicle-induced wind at the median strip.

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Median Rank를 이용한 연구인력 평가 시스템 (Development of Research Personnel Evaluation System Using Median Rank)

  • 이성기;윤덕균
    • 산업경영시스템학회지
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    • 제21권47호
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    • pp.169-179
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    • 1998
  • Median rank is used to systemize the evaluation of research personnel in a research institution. Suggested evaluation system is purposed to enhance the fairness, distinguish the factors of evaluation and maximize the synergy of researchers. The factors of evaluation are largely divided into the subjective and the objective factor. The final rank of the researchers is determined with the converted median rank value. The propriety of applying median rank is tested by Spearman's rank correlation coefficient. We also suggest the method of determining the rank of researchers. This evaluation system is not fixed in special case but can be changed in situation. It also can be applied to any other personnel evaluation system through the appropriate revision.

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잡음제거를 위한 하이브리드 필터 (Hybrid filter for noise reduction)

  • 조범석;김영로
    • 디지털산업정보학회논문지
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    • 제7권4호
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    • pp.133-139
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    • 2011
  • In this paper, we propose a hybrid filter for noise reduction. The proposed method adjusts rational filtering direction according to an edge in the image using median filtered data. Rational filter modulates the coefficients of a linear lowpass filter to limit its action in presence of image details. By the ratio of polynomials in the input variables, rational filter reduces noise adaptively. Median filter is widely used to reduce impulse noise, but removes some details for highly corrupted images. Also, desirable details are removed when the window size is large. Our proposed algorithm combines rational filter and median filter. Thus, proposed method not only preserves edge, but also reduces noise in uniform region. Experimental results show that our proposed method has better quality than those by existing median and rational filtering methods.