• Title/Summary/Keyword: Median

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Median Ranked Ordering-Set Sample Test for Ordered Alternatives

  • Kim, Dong-Hee;Ock, Bong-Seak
    • Communications for Statistical Applications and Methods
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    • v.15 no.6
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    • pp.947-957
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    • 2008
  • In this paper, we consider the c-sample location problem for ordered alternatives using median ranked ordering-set samples(MROSS). We propose the test statistic using the median of samples that have the same ranked order in each cycle of ranted ordering-set sample(ROSS). We obtain the asymptotic property of the proposed test statistic and Pitman efficiency with respect to other test statistic. In simulation study, our proposed test statistic has good powers for some underlying distributions we consider.

A Study on the Algorithm for Adaptive Odd/Even Multi-shell Median Filter (가변 문턱조건을 이용한 odd/even median filter 알고리즘)

  • 조상복;이일권
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.495-498
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    • 1999
  • In this paper, we propose the adaptive Odd/Even Multi-shell Median Filter(adaptive O/E MMF) to improve the defect that Modified Multi-shell Median Filter(MMMF) can not recover missing lines of vertical and cross direction. This filter uses odd/even multi-shells and new proposed threshold strategy The performance of the proposed filter is evaluated over image 'airfield 'by using MATLAB. As the proposed threshold strategy eliminate the number of redundant replacement, it suppresses impulse noise and recovers missing lines.

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Forensic Decision of Median Filtering by Pixel Value's Gradients of Digital Image (디지털 영상의 픽셀값 경사도에 의한 미디언 필터링 포렌식 판정)

  • RHEE, Kang Hyeon
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.6
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    • pp.79-84
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    • 2015
  • In a distribution of digital image, there is a serious problem that is a distribution of the altered image by a forger. For the problem solution, this paper proposes a median filtering (MF) image forensic decision algorithm using a feature vector according to the pixel value's gradients. In the proposed algorithm, AR (Autoregressive) coefficients are computed from pixel value' gradients of original image then 1th~6th order coefficients to be six feature vector. And the reconstructed image is produced by the solution of Poisson's equation with the gradients. From the difference image between original and its reconstructed image, four feature vector (Average value, Max. value and the coordinate i,j of Max. value) is extracted. Subsequently, Two kinds of the feature vector combined to 10 Dim. feature vector that is used in the learning of a SVM (Support Vector Machine) classification for MF (Median Filtering) detector of the altered image. On the proposed algorithm of the median filtering detection, compare to MFR (Median Filter Residual) scheme that had the same 10 Dim. feature vectors, the performance is excellent at Unaltered, Averaging filtering ($3{\times}3$) and JPEG (QF=90) images, and less at Gaussian filtering ($3{\times}3$) image. However, in the measured performances of all items, AUC (Area Under Curve) by the sensitivity and 1-specificity is approached to 1. Thus, it is confirmed that the grade evaluation of the proposed algorithm is 'Excellent (A)'.

Adjacent Pixels based Noise Mitigation Filter in Salt & Pepper Noise Environments (Salt & Pepper 잡음 환경에서 인접 픽셀 기반 잡음 완화 필터)

  • Seong, Chi Hyuk;Shin, Soo Young
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.6
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    • pp.65-71
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    • 2017
  • Digital images and videos are subject to various types of noise during storage and transmission. Among these noises, Salt & Pepper noise degrades the compression efficiency of the original data and causing deterioration of performance in edge detection or segmentation used in an image processing method. In order to mitigate this noise, there are many filters such as Median Filter, Weighted Median Filter, Center Weighted Median Filter, Switching Weighted Median Filter and Adaptive Median Filter. However these methods are inferior in performance at high noise density. In this paper we propose a new type of filter for noise mitigation in wireless communication environment where Salt & Pepper noise occurs. The proposed filter detects the location of the damaged pixel by Salt & Pepper noise detection and mitigates the noise by using adjacent pixel values which are not damaged in a certain area. Among the proposed filters, the performance of the filter using the $3{\times}3$ error mask is compared with that of the conventional methods and it is confirmed that when density of noise in the image is 95%, their performances are improved as 13.24 dB compared to MF and 13.09 dB compared to AMF.

Support Vector Machine and Improved Adaptive Median Filtering for Impulse Noise Removal from Images (영상에서 Support Vector Machine과 개선된 Adaptive Median 필터를 이용한 임펄스 잡음 제거)

  • Lee, Dae-Geun;Park, Min-Jae;Kim, Jeong-Uk;Kim, Do-Yoon;Kim, Dong-Wook;Lim, Dong-Hoon
    • The Korean Journal of Applied Statistics
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    • v.23 no.1
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    • pp.151-165
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    • 2010
  • Images are often corrupted by impulse noise due to a noise sensor or channel transmission errors. The filter based on SVM(Support Vector Machine) and the improved adaptive median filtering is proposed to preserve image details while suppressing impulse noise for image restoration. Our approach uses an SVM impulse detector to judge whether the input pixel is noise. If a pixel is detected as a noisy pixel, the improved adaptive median filter is used to replace it. To demonstrate the performance of the proposed filter, extensive simulation experiments have been conducted under both salt-and-pepper and random-valued impulse noise models to compare our method with many other well known filters in the qualitative measure and quantitative measures such as PSNR and MAE. Experimental results indicate that the proposed filter performs significantly better than many other existing filters.

The Effects of Upper Limb Neuro Dynamic Treatment on the Pain, Grip Strength and Nerve Conduction Velocity of Patients with Carpal Tunnel Syndrome (상지역동학 치료가 수근관 증후군 환자의 통증, 악력, 신경전도속도에 미치는 효과)

  • Yu, Seong-Hun;Park, Sung-Doo;Kim, Tae-Won;Song, Hyun-Seung;Kim, Jin-Young
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.18 no.1
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    • pp.49-56
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    • 2012
  • Background: When applying the upper limb neurodynamic treatment ULNT1 and upper limb neurodynamic treatment ULNT2, The object of this study evaluates the pain and grip strength, nerve conduction velocity and tries to present the treatment that is effective in the carpal tunnel syndrome through the comparison of effect between tests. Methods: The ULNT1 (n=10) and ULNT2 (n=10) was applied to the carpal tunnel syndrome in patient of 20 subject for 10 time 5 set during 4 weeks. Both groups received conventional physical therapy (hot pack with 30 minutes and ICT with 15 minutes and ultra sound with 15 minutes). Results: The ULNT1 showed the difference which the result of this study significantly in the median nerve motor latency, median nerve motor amplitude, median nerve sensory latency, median nerve sensory amplitude, grip strength and pain. ULNT2 showed the difference significantly in median nerve motor latency, median nerve motor amplitude, median nerve sensory latency, median nerve sensory amplitude and pain. Conclusions: If it implements by applying the traditional physiotherapy and ULNT1 and ULNT2 to the carpal tunnel syndrome subjects according to the subject state and function, the remedial value can be more enhanced.

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Median Filtering Detection of Digital Images Using Pixel Gradients

  • RHEE, Kang Hyeon
    • IEIE Transactions on Smart Processing and Computing
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    • v.4 no.4
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    • pp.195-201
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    • 2015
  • For median filtering (MF) detection in altered digital images, this paper presents a new feature vector that is formed from autoregressive (AR) coefficients via an AR model of the gradients between the neighboring row and column lines in an image. Subsequently, the defined 10-D feature vector is trained in a support vector machine (SVM) for MF detection among forged images. The MF classification is compared to the median filter residual (MFR) scheme that had the same 10-D feature vector. In the experiment, three kinds of test items are area under receiver operating characteristic (ROC) curve (AUC), classification ratio, and minimal average decision error. The performance is excellent for unaltered (ORI) or once-altered images, such as $3{\times}3$ average filtering (AVE3), QF=90 JPEG (JPG90), 90% down, and 110% up to scale (DN0.9 and Up1.1) images, versus $3{\times}3$ and $5{\times}5$ median filtering (MF3 and MF5, respectively) and MF3 and MF5 composite images (MF35). When the forged image was post-altered with AVE3, DN0.9, UP1.1 and JPG70 after MF3, MF5 and MF35, the performance of the proposed scheme is lower than the MFR scheme. In particular, the feature vector in this paper has a superior classification ratio compared to AVE3. However, in the measured performances with unaltered, once-altered and post-altered images versus MF3, MF5 and MF35, the resultant AUC by 'sensitivity' (TP: true positive rate) and '1-specificity' (FN: false negative rate) is achieved closer to 1. Thus, it is confirmed that the grade evaluation of the proposed scheme can be rated as 'Excellent (A)'.

Entrapment Neuropathy of Median and Ulnar Nerve Due to Soft Tissue Chondroma: A Case Report (연부조직 연골종에 의한 정중, 척골포착신경병증: 증례보고)

  • Hong, Sung-Taek;Ahn, Duck-Sun
    • Archives of Plastic Surgery
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    • v.37 no.6
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    • pp.815-818
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    • 2010
  • Purpose: Soft tissue chondroma is a rare benign tumor, found mainly on the palm and sole and grows slowly. Typically, mature hyaline cartilage is the dominant pathological feature. There are reports that assert soft tissue chondromas to be a cause of median nerve entrapment syndrome. However, this is the first case report showing soft tissue chondroma to be a cause of simultaneous median and ulnar neuropathy. Methods: A 62 year-old woman presented with chief complaints of numbness and hypoesthesia of her right palm for 4 to 5 years, and a palpable mass on her right palm that had been increasing in size slowly for 3 years. Physical examination revealed a firm, mobile, non-tender and about $3{\times}3\;cm^2$ sized mass in the center of the right palm. Electromyography showed entrapment neuropathy of the median and ulnar nerve. Ultrasonography showed an approximately $5.7\;cm^2$ mass below the flexor tendon of ring finger. Upon surgical excision, a $3{\times}3\;cm^2$ mass attached to the flexor digitorum profundus of ring finger and redness and hypertrophy of both the median and ulnar nerve were discovered. Mass excision was performed gently and the specimen was referred for histopathologic study. Mass excision resulted in median and ulnar nerve release. Results: The pathology report confirmed the mass to be a soft tissue chondroma with mature hyaline cartilage. The patient exhibited post-operative improvement of her symptoms and did not show any complications. Conclusion: This is the first case report showing soft tissue chondroma to be a cause of simultaneous median and ulnar neuropathy.

Real-time 2-D Separable Median Filter (실시간 2차원 Separable 메디안 필터)

  • Jae Gil Jeong
    • Journal of the Korea Computer Industry Society
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    • v.3 no.3
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    • pp.321-330
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    • 2002
  • A 2-D median filter has many applications in various image and video signal processing areas. The rapid development in VLSI technology makes it possible to implement a real-time or near real-time 2-D median filter with reasonable cost. For the efficient VLSI implementation, the algorithm should have characteristics such as small memory requirements, regular computations, and local data transfers. This paper presents an architecture of the real-time two-dimensional separable median filter which has appropriate characteristics for the VLSI implementation. For the efficient two-dimensional median filter, a separable two-dimensional median filtering structure and a bit-sliced pipelined median searching algorithm are used. A behavioral simulator is implemented with C language and used for the analysis of the presented architecture.

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Rare Tumors Causing Median Nerve Compression in Adults-A Narrative Review

  • Natroshvili, Tinatin;Peperkamp, Kirsten;Malyar, Masoud A.;Wijnberg, David;Heine, Erwin P.;Walbeehm, Erik T.
    • Archives of Plastic Surgery
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    • v.49 no.5
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    • pp.656-662
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    • 2022
  • The median nerve can be compressed due to a tumor along the course of the median nerve, causing typical compression symptoms or even persistence or recurrence after an operation. The aim of this review is to provide a comprehensive overview of rare tumors described in recent publications that cause median nerve compression and to evaluate treatment options. The PubMed, Embase, and Web of Science databases were searched for studies describing median nerve compression due to a tumor in adults, published from the year 2000 and written in English. From 94 studies, information of approximately 100 patients have been obtained. Results The rare tumors causing compression were in 32 patients located at the carpal tunnel, in 21 cases in the palm of the hand, and 28 proximal from the carpal tunnel. In the other cases the compression site extended over a longer trajectory. There were 37 different histological types of lesions. Complete resection of the tumor was possible in 58 cases. A total of 8 patients presented for the second time after receiving initial therapy. During follow-up, three cases of recurrence were reported with a mean follow-up period of 11 months. The most common published cause of median nerve compression is the lipofibromatous hamartoma. Besides the typical sensory and motor symptoms of median nerve compression, a thorough physical examination of the complete upper extremity is necessary to find any swelling or triggering that might raise suspicion of the presence of a tumor.