• Title/Summary/Keyword: threshold methods

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A Study on the Dynamic Binary Fingerprint Recognition Method using Artificial Intelligence (인공지능기법을 이용한 동적 이진화 지문인식 방법에 관한 연구)

  • Kang, Jong-Yoon;Lee, Joo-Sang;Lee, Jae-Hyun;Kong, Suk-Min;Kim, Dong-Han;Lee, Sang-Bae
    • Journal of the Korean Institute of Intelligent Systems
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    • v.13 no.1
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    • pp.57-62
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    • 2003
  • Among the procedure of automatic fingerprint recognition, binary code is important for the optimum thinning and singular point extraction while reserving the fingerprint image data. Binarization is to convert gray scale images into 0s and 255s values. For this conversion, you should set up the proper threshold value not to lose fingerprint image data. In this paper, we suggest the method to extract the standard threshold in real-time from fingerprint images entered by applying artificial intelligent methods in the binary code procedure. We show improved features while comparing the experiment results with the existing methods.

The Optimal Method to Determine Damage Threshold of Rock using Hwangdeung Granite (황등화강암을 이용한 암석의 손상기준 결정방법 연구)

  • Jang, Bo-An;Ji, Hoon;Jang, Hyun-Shic
    • The Journal of Engineering Geology
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    • v.20 no.1
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    • pp.89-100
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    • 2010
  • Although various methods for determination of damage threshold in rock have been suggested, clear damage thresholds were determined by some methods, but different thresholds were measured by other methods. We determined the damage thresholds in Hangdeung granite using all the methods suggested, and investigated the best methods, applicability and errors of each method. The crack initiation threshold and the crack damage threshold which are important in investigation of characteristics of crack development and failure were verified by field strength ratio method and long-term constant load test. The crack closure stress and the crack initiation stress were 57.5 MPa and 77.6 MPa, and the most exact values were yielded by crack volumetric strain. The secondary crack initiation stress was 90.6 MPa and AE event count and AE event count rate were the effective methods. The volumetric stiffness, AE event count and AE event count rate were the most effective methods for determination of crack coalescence threshold and crack coalescence stress was 110.3 MPa. The crack damage stress was 127.5 MPa and was measured correctly by volumetric stiffness and AE event count rate. The ratio between crack initiation stress and uniaxial compressive strength was 0.47 which was very similar with the FSR value of 0.46. The ratio between crack damage stress and uniaxial compressive strength was almost the same as the ratio between long-term strength and uniaxial compressive strength, indicating that the crack initiation stress and the crack damage stress measured were correct.

The difference of Quantitative Analysis According to the Method of Region of Interest Setting in $^{99m}Tc$-DMSA Renal Scan ($^{99m}Tc$-DMSA 신장 검사에서 ROI 설정 방법에 따른 정량분석 차이에 관한 연구)

  • Lee, Jong-Hun;Shim, Dong-Oh
    • The Korean Journal of Nuclear Medicine Technology
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    • v.14 no.1
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    • pp.73-77
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    • 2010
  • Purpose: The nuclear medicine technology has been changed. The hard ware is developed so much. Also the soft ware performs a meritorious deed for the development of nuclear medicine technology. We could use the automated region of interest (ROI) instead of manual ROI. We want to know that what difference of quantitative analysis is there between automated ROI and manual ROI Materials and Methods: There are three experimental to make results. The first is what comparing the renal automated ROI and manual ROI. The second is that we compared three threshold ROI that size is difference each others with visible decision. The third is that we compared full, half, quarter automated background, and survey relative function. Results: Although the first has statistically not significant difference, the second and third have significant difference. Threshold, setting smaller threshold then renal outline or bigger, has statistically significant difference (p<0.01). The third is performed with the first experimental. Full background has significant difference, comparing each three type background (p<0.05). Conclusion: The results that there is not significant difference between automated ROI and manual ROI will increase objectivity and operator's convenience. We could know that smaller threshold then renal out line has significant difference in the second experimental. And the third experimental has results because of a increased background nearby live and spleen.

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Automatic Estimation of Threshold Values for Change Detection of Multi-temporal Remote Sensing Images (다중시기 원격탐사 화상의 변화탐지를 위한 임계치 자동 추정)

  • 박노욱;지광훈;이광재;권병두
    • Korean Journal of Remote Sensing
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    • v.19 no.6
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    • pp.465-478
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    • 2003
  • This paper presents two methods for automatic estimation of threshold values in unsupervised change detection of multi-temporal remote sensing images. The proposed methods consist of two analytical steps. The first step is to compute the parameters of a 3-component Gaussian mixture model from difference or ratio images. The second step is to determine a threshold value using Bayesian rule for minimum error. The first method which is an extended version of Bruzzone and Prieto' method (2000) is to apply an Expectation-Maximization algorithm for estimation of the parameters of the Gaussian mixture model. The second method is based on an iterative thresholding algorithm that successively employs thresholding and estimation of the model parameters. The effectiveness and applicability of the methods proposed here were illustrated by two experiments and one case study including the synthetic data sets and KOMPSAT-1 EOC images. The experiments demonstrate that the proposed methods can effectively estimate the model parameters and the threshold value determined shows the minimum overall error.

The Study of Edge Extract Methods Using Improved Detect Mask (개선된 검출 마스크를 이용한 에지추출 방법들에 관한 연구)

  • Shin, Choong-Ho
    • Journal of Korea Multimedia Society
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    • v.12 no.2
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    • pp.191-199
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    • 2009
  • In this paper, the improved edge extract methods is proposed in order to extract edge. For the correct and fast detect, the binary image using the threshold value is applied for a experiment. For the experimental analysis, we compare the existing edge methods with the improved methods. Hereby, the exist methods are the sobel, robert, and prewitt. and the improved methods use the existing methods which is applied mask variations. The merits of the improved mothods have a result of a little erosion, a apparent edge. Specially, we use the grey image of medical image for the experimental analysis and then apply threshold value for a result image. After that, we acquire a apparent edge. For a quantitative analysis of the each methods, the each images was applied a histogram. As a result, we prove the merit of the improved methods using a analytical graph of the medical images.

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Compare Maternal Pressure Pain Threshold and which of Healthy non Delivered Women and Men (산모와 건강한 미산부 및 남자의 압통 역치 비교에 관한 연구)

  • Jeong, Jae-Cheol;Roh, Jin-Ju;Nam, Ju-Young;Jeon, Gyu-Il;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.21 no.1
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    • pp.199-205
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    • 2008
  • Purpose: This study was conducted for evaluating whether the postpartum women has lower threshold than healthy non delivered women and men. Methods: We divided the groups by three. Group I is consist of postpartum women who have delivered within 7days. Group II is nonparous women, and the Group III is consist of men. Pain threshold in 6 specific points was measured using the digital algometer from each groups. Results: Pain threshold was obviously higher in Group III than Group I, II, And group II’s threshold was significantly higher than group I’s Conclusion: This study shows the postpartum women had lower pressure pain threshold than non delivered women and men. So clinicians should consider the physiologic and psychologic aspects for the pain control if they meet postpartum women.

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One-dimensional and Image Signal Denoising Using an Adaptive Wavelet Shrinkage Filter (적응적 웨이블렛 수축 필터를 이용한 일차원 및 영상 신호의 잡음 제거)

  • Lim, Hyun;Park, Soon-Young;Oh, Il-Whan
    • The Journal of the Acoustical Society of Korea
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    • v.19 no.4
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    • pp.3-15
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    • 2000
  • In this paper we present a new image denoising filter that can suppress additive noise components while preserving signal components in the wavelet domain. The proposed filter, which we call an adaptive wavelet shrinkage(AWS) filter, is composed of two operators: the wavelet killing operator and the adaptive shrinkage operator. Each operator is selected based on the threshold value which is estimated adaptively by using the local statistics of the wavelet coefficients. In the wavelet killing operation, the small wavelet coefficients below the threshold value are replaced by zero to suppress noise components in the wavelet domain. The adaptive shrinkage operator attenuates noise components from the wavelet components above the threshold value adaptively. The experimental results show that the proposed filter is more effective than the other methods in preserving signal components while suppressing noise.

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Variable Dynamic Threshold Method for Video Cut Detection (동영상 컷 검출을 위한 가변형 동적 임계값 기법)

  • 염성주;김우생
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.4A
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    • pp.356-363
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    • 2002
  • Video scene segmentation is fundamental role for content based video analysis and many kinds of scene segmentation schemes have been proposed in previous researches. However, there is a problem, which is to find optimal threshold value according to various kinds of movies and its content because only fixed single threshold value usually used for cut detection. In this paper, we proposed the variable dynamic threshold method, which change the threshold value by a probability distribution of cut detection interval and information of frame feature differences and cut detection interval in previous cut detection is used to determine the next cut detection. For this, we present a cut detection algorithm and a parameter generation method to change the threshold value in runtime. We also show the proposed method, which can minimize fault alarm rate than the existing methods efficiently by experimental results.

A Simple and Robustness Algorithm for ECG R- peak Detection

  • Rahman, Md Saifur;Choi, Chulhyung;Kim, Young-pil;Kim, Sikyung
    • Journal of Electrical Engineering and Technology
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    • v.13 no.5
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    • pp.2080-2085
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    • 2018
  • There have been numerous studies that extract the R-peak from electrocardiogram (ECG) signals. All of these studies can extract R-peak from ECG. However, these methods are complicated and difficult to implement in a real-time portable ECG device. After filtration choosing a threshold value for R-peak detection is a big challenge. Fixed threshold scheme is sometimes unable to detect low R-peak value and adaptive threshold sometime detect wrong R-peak for more adaptation. In this paper, a simple and robustness algorithm is proposed to detect R-peak with less complexity. This method also solves the problem of threshold value selection. Using the adaptive filter, the baseline drift can be removed from ECG signal. After filtration, an appropriate threshold value is automatically chosen by using the minimum and maximum value of an ECG signals. Then the neighborhood searching scheme is applied under threshold value to detect R-peak from ECG signals. Proposed method improves the detection and accuracy rate of R-peak detection. After R-peak detection, we calculate heart rate to know the heart condition.

Effect of oral environment(salivary flow, taste recognition threshold) of adults over 40 years on oral health influence point(OHIP-14) (40대 이상 성인의 구강환경요인(타액분비량, 미각인지역치)이 구강건강영향지수(OHIP-14)에 미치는 영향)

  • Kim, Ji-Haw;Kim, Gi-Ug
    • Journal of Korean society of Dental Hygiene
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    • v.13 no.5
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    • pp.749-757
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    • 2013
  • Objectives : The aim of the study is to investigate the relationship between salivary flow, palate recognition threshold, DMFT index and oral health influence point (OHIP-14) of the adults over 40 years old. Methods : Salivary flow and taste recognition threshold were measured in 220 adults over 40 years old from three dental clinics in Daegu from January 3 to February 4, 2012. A total of 208 questionnaires were analyzed. Results : The adults recognized the sour taste in low concentration level when the salivary flow was faster. DMFT index was low in those who recognized sweet and sour taste that affected OHIP-14. Conclusions : Tooth decaying food must be restricted because of its high acidity in the past despite the individuals' taste recognition threshold was neglected. Before the diet control, it is necessary to measure the taste threshold of the individuals. Training for improving salivary flow is very important to prevent dental caries and to preserve good taste.