• Title/Summary/Keyword: Adaptive Threshold Method

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Estimation of high-dimensional sparse cross correlation matrix

  • Yin, Cao;Kwangok, Seo;Soohyun, Ahn;Johan, Lim
    • Communications for Statistical Applications and Methods
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    • v.29 no.6
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    • pp.655-664
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    • 2022
  • On the motivation by an integrative study of multi-omics data, we are interested in estimating the structure of the sparse cross correlation matrix of two high-dimensional random vectors. We rewrite the problem as a multiple testing problem and propose a new method to estimate the sparse structure of the cross correlation matrix. To do so, we test the correlation coefficients simultaneously and threshold the correlation coefficients by controlling FRD at a predetermined level α. Further, we apply the proposed method and an alternative adaptive thresholding procedure by Cai and Liu (2016) to the integrative analysis of the protein expression data (X) and the mRNA expression data (Y) in TCGA breast cancer cohort. By varying the FDR level α, we show that the new procedure is consistently more efficient in estimating the sparse structure of cross correlation matrix than the alternative one.

The Development of a Marker Detection Algorithm for Improving a Lighting Environment and Occlusion Problem of an Augmented Reality (증강현실 시스템의 조명환경과 가림현상 문제를 개선한 마커 검출 알고리즘 개발)

  • Lee, Gyeong Ho;Kim, Young Seop
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.1
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    • pp.79-83
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    • 2012
  • We use adaptive method and determine threshold coefficient so that the algorithm could decide a suitable binarization threshold coefficient of the image to detecting a marker; therefore, we solve the light influence on the shadow area and dark region. In order to improve the speed for reducing computation we created Integral Image. The algorithm detects an outline of the image by using canny edge detection for getting damage or obscured markers as it receives the noise removed picture. The strength of the line of the outline is extracted by Hough transform and it extracts the candidate regions corresponding to the coordinates of the corners. Markers extracted using the equation of a straight edge to find the coordinates. By using the equation of straight the algorithm finds the coordinates the corners. of extracted markers. As a result, even if all corners are obscured, the algorithm can find all of them and this was proved through the experiment.

3D Reconstruction System of Teeth for Dental Simulation (치과 진료 시뮬레이션을 위한 3차원 치아의 재구성 시스템)

  • Heo, Hoon;Choi, Won-Jun;Chae, Ok-Sam
    • The KIPS Transactions:PartB
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    • v.11B no.2
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    • pp.133-140
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    • 2004
  • Recently, the dental information systems were rapidly developed in order to store and process the data of patients. But, these systems should serve a doctor a good quality information against disease for diagnostic and surgery purpose so as to success in this field. This function of the system it important to persuade patients to undergo proper surgical operation they needed. Hence, 3D teeth model capable of simulating the dental surgery and treatment is necessary Teeth manipulation of dentistry is performed on individual tooth in dental clinic. io, 3D teeth reconstruction system should have the techniques of segmentation and 3D reconstruction adequate for individual tooth. In this paper, we propose the techniques of adaptive optimal segmentation to segment the individual area of tooth, and reconstruction method of tooth based on contour-based method. Each tooth can be segmented from neighboring teeth and alveolar bone in CT images using adaptive optimal threshold computed differently on tooth. Reconstruction of individual tooth using results of segmentation can be manipulated according to user's input and make the simulation of dental surgery and treatment possible.

An Adaptive I/Q Diversity Combining Method for UHF RFID Reader Systems (UHF 대역 RFID 리더 시스템을 위한 적응형 I/Q 다이버시티 결합 알고리즘)

  • Yoon, Chang-Seok;Nam, Sung-Sik;Cho, Sung-Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.1B
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    • pp.176-182
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    • 2010
  • In this paper, we propose an adaptive I/Q diversity combining scheme which reduces unnecessary computations while maintaining the required performance level. The system with the proposed scheme adaptively applies a proper combining scheme among the conventional selective scheme and combining scheme based on the comparison result between the estimated instantaneous SNR and the pre-determined threshold. As a result, the system with our proposed scheme can reduce the computational load while maintaining the required performance level. Some selected simulation results show that the system with the proposed scheme can decrease the unnecessary computations compared with the system with the conventional schemes while maintaining the required performance level.

Robust k-means Clustering-based High-speed Barcode Decoding Method to Blur and Illumination Variation (블러와 조명 변화에 강인한 k-means 클러스터링 기반 고속 바코드 정보 추출 방법)

  • Kim, Geun-Jun;Cho, Hosang;Kang, Bongsoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.1
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    • pp.58-64
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    • 2016
  • In this paper presents Robust k-means clustering-based high-speed bar code decoding method to blur and lighting. for fast operation speed and robust decoding to blur, proposed method uses adaptive local threshold binarization methods that calculate threshold value by dividing blur region and a non-blurred region. Also, in order to prevent decoding fail from the noise, decoder based on k-means clustering algorithm is implemented using area data summed pixel width line of the same number of element. Results of simulation using samples taken at various worst case environment, the average success rate of proposed method is 98.47%. it showed the highest decoding success rate among the three comparison programs.

Adaptive Background Subtraction Based on Genetic Evolution of the Global Threshold Vector (전역 임계치 벡터의 유전적 진화에 기반한 적응형 배경차분화)

  • Lim, Yang-Mi
    • Journal of Korea Multimedia Society
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    • v.12 no.10
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    • pp.1418-1426
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    • 2009
  • There has been a lot of interest in an effective method for background subtraction in an effort to separate foreground objects from a predefined background image. Promising results on background subtraction using statistical methods have recently been reported are robust enough to operate in dynamic environments, but generally require very large computational resources and still have difficulty in obtaining clear segmentation of objects. We use a simple running-average method to model a gradually changing background, instead of using a complicated statistical technique. We employ a single global threshold vector, optimized by a genetic algorithm, instead of pixel-by-pixel thresholds. A new fitness function is defined and trained to evaluate segmentation result. The system has been implemented on a PC with a webcam, and experimental results on real images show that the new method outperforms an existing method based on a mixture of Gaussian.

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Dominant Path Selection Algorithm for Channel Estimation of MUD Based Receiver (MUD 기반 수신기의 채널 추정을 위한 주 경로 선택 알고리즘)

  • Byon Hyoung-joo;Seo In-kwon;Kim Younglok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.5C
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    • pp.398-405
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    • 2005
  • The multiuser detection (MUD) based wireless receiver requires more accurate channel estimation than the single user detection (SUD) schemes such as Rake receiver, and hence the post processing is required for MUD to clean up the estimated channel coefficients by eliminating the noise only coefficients. The adaptive post processing method is proposed in order to provide more accurate channel responses and the power level of the background noise and interferences at the cost of the negligible processing delay compared to the conventional method based on the threshold test with the threshold value relative to the noise variance. The simulations are performed in 3GPP-TDD mode environment. The results show that the noise estimation error of the proposed method is maximum $10\%$, which is much smaller than $50\%$ maximum error of the conventional method.

Image Edge Detection Technique for Pathological Information System (병리 정보 시스템을 위한 이미지 외곽선 추출 기법 연구)

  • Xiao, Xie;Oh, Sangyoon
    • KIPS Transactions on Software and Data Engineering
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    • v.5 no.10
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    • pp.489-496
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    • 2016
  • Thousands of pathological images are produced daily per hospital and they are stored and managed by a pathology information system (PIS). Since image edge detection is one of fundamental analysis tools for pathological images, many researches are targeted to improve accuracy and performance of image edge detection algorithm of HIS. In this paper, we propose a novel image edge detection method. It is based on Canny algorithm with adaptive threshold configuration. It also uses a dividing ruler to configure the two threshold instead of whole image to improve the detection ratio of ruler itself. To verify the effectiveness of our proposed method, we conducted empirical experiments with real pathological images(randomly selected image group, image group that was unable to detect by conventional methods, and added noise image group). The results shows that our proposed method outperforms and better detects compare to the conventional method.

Video-Dissolve Detection using Characteristics of Neighboring Scenes (이웃 장면들의 특성을 이용한 비디오 디졸브 검출)

  • 원종운;최재각;박철현;김범수;곽동민;오상근;박길흠
    • Journal of KIISE:Information Networking
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    • v.30 no.4
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    • pp.504-512
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    • 2003
  • In this paper, we propose a new adaptive dissolve detection method based on the analysis of a dissolve modeling error which is the difference between an ideally modeled dissolve curve with no correlation and an actual dissolve curve including a correlation. The proposed dissolve detection method consists of two steps. First, candidate dissolve regions are extracted using the characteristics of a downward convex parabola, then each candidate region is verified based oil the dissolve modeling error. If the dissolve modeling error for a candidate region is less than a threshold defined by the target modeling error with a target correlation, the candidate region is determined as a resolve region with a lower correlation than the target correlation. The threshold is adaptively determined based on the variances between the candidate regions and the target correlation. By considering the correlation between neighbor scenes, the proposed method is able to be a semantic scene-change detector. The proposed method was tested on various types of data and its performance proved to be more accurate and reliable regardless of variation of variance of test sequences when compared with other commonly use methods.

A deep learning-based approach for feeding behavior recognition of weanling pigs

  • Kim, MinJu;Choi, YoHan;Lee, Jeong-nam;Sa, SooJin;Cho, Hyun-chong
    • Journal of Animal Science and Technology
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    • v.63 no.6
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    • pp.1453-1463
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    • 2021
  • Feeding is the most important behavior that represents the health and welfare of weanling pigs. The early detection of feed refusal is crucial for the control of disease in the initial stages and the detection of empty feeders for adding feed in a timely manner. This paper proposes a real-time technique for the detection and recognition of small pigs using a deep-leaning-based method. The proposed model focuses on detecting pigs on a feeder in a feeding position. Conventional methods detect pigs and then classify them into different behavior gestures. In contrast, in the proposed method, these two tasks are combined into a single process to detect only feeding behavior to increase the speed of detection. Considering the significant differences between pig behaviors at different sizes, adaptive adjustments are introduced into a you-only-look-once (YOLO) model, including an angle optimization strategy between the head and body for detecting a head in a feeder. According to experimental results, this method can detect the feeding behavior of pigs and screen non-feeding positions with 95.66%, 94.22%, and 96.56% average precision (AP) at an intersection over union (IoU) threshold of 0.5 for YOLOv3, YOLOv4, and an additional layer and with the proposed activation function, respectively. Drinking behavior was detected with 86.86%, 89.16%, and 86.41% AP at a 0.5 IoU threshold for YOLOv3, YOLOv4, and the proposed activation function, respectively. In terms of detection and classification, the results of our study demonstrate that the proposed method yields higher precision and recall compared to conventional methods.