• Title/Summary/Keyword: variable threshold method

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Robust Pupil Detection using Rank Order Filter and Cross-Correlation (Rank Order Filter와 상호상관을 이용한 강인한 눈동자 검출)

  • Jang, Kyung-Shik;Park, Sung-Dae
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.7
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    • pp.1564-1570
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    • 2013
  • In this paper, we propose a robust pupil detection method using rank order filter and cross-correlation. Potential pupil candidates are detected using rank order filter. Eye region is binarized using variable threshold to find eyebrow, and pupil candidates at the eyebrow are removed. The positions of pupil candidates are corrected, the pupil candidates are grouped into pairs based on geometric constraints. A similarity measure is obtained for two eye of each pair using cross-correlation, we select a pair with the largest similarity measure as a final pupil. The experiments have been performed for 500 images of the BioID face database. The results show that it achieves the high detection rate of 96.8% and improves about 11.6% than existing method.

Random Noise Addition for Detecting Adversarially Generated Image Dataset (임의의 잡음 신호 추가를 활용한 적대적으로 생성된 이미지 데이터셋 탐지 방안에 대한 연구)

  • Hwang, Jeonghwan;Yoon, Ji Won
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.6
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    • pp.629-635
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    • 2019
  • In Deep Learning models derivative is implemented by error back-propagation which enables the model to learn the error and update parameters. It can find the global (or local) optimal points of parameters even in the complex models taking advantage of a huge improvement in computing power. However, deliberately generated data points can 'fool' models and degrade the performance such as prediction accuracy. Not only these adversarial examples reduce the performance but also these examples are not easily detectable with human's eyes. In this work, we propose the method to detect adversarial datasets with random noise addition. We exploit the fact that when random noise is added, prediction accuracy of non-adversarial dataset remains almost unchanged, but that of adversarial dataset changes. We set attack methods (FGSM, Saliency Map) and noise level (0-19 with max pixel value 255) as independent variables and difference of prediction accuracy when noise was added as dependent variable in a simulation experiment. We have succeeded in extracting the threshold that separates non-adversarial and adversarial dataset. We detected the adversarial dataset using this threshold.

Sex Ratio Determination by Quantitative Real Time PCR using Amelogenin Gene in Porcine Sperm

  • Hwang, You-Jin;Bae, Mun-Sook;Yang, Jae-Hun;Kim, Bo-Kyoung;Kim, Sang-Ok;Lee, Eun-Soo;Choi, Sun-Gyu;Kwon, Ye-Ri;Seo, Min-Hae;Park, Choon-Keun;Kim, Dae-Young
    • Journal of Embryo Transfer
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    • v.24 no.3
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    • pp.225-230
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    • 2009
  • Sex-sorting of sperm is an assisted reproductive technology (ART) used by the livestock industry for the mass production of animals of a desired sex. The standard method for sorting sperm is the detection of DNA content differences between X and Y chromosome-bearing sperm by flow cytometry. However, this method has variable efficiency and therefore requires verification by a second method. We have developed a sex determination method based on quantitative real-time polymerase chain reaction (qPCR) of the porcine amelogenin (AMEL) gene. The AMEL gene is present on both the X and the Y chromosome, but the length and sequence of its noncoding regions differ between the X and Y chromosomes. By measuring the threshold cycle (Ct) of qPCR, we were able to calculate the relative frequency of X chromosome. Two sets of AMEL primers were used in these studies. One set (AME) targeted AMEL gene sequences present in both X and Y chromosome, but produced PCR products of different lengths for each chromosome. The other set (AXR) bound to AMEL gene sequences present on the X chromosome but absent esholthe Y-chromosome. Relative product levels were calculated by normalizing the AXR fluorescence to the AME fluorescence. The AMEL method accurately predicted the sex ratios of boar sperm, demonstrating that it has potential value as a sex determination method.

Traffic Management Scheme for Supporting QoS of VBR/ABR Services in ATM Switching Systems (ATM 스위칭 시스템의 VBR/ABR 서비스 품질 지원을 위한 트랙픽 관리 기법)

  • 유인태
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.8A
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    • pp.1160-1168
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    • 2000
  • This paper presents a real-time integrated traffic management (RITM) scheme that can effectively manage variable bit rate (VBR) and available bit rate (ABR) traffics having unpredictable characteristics in asynchronous transfer mode (ATM) networks. An unique feature of this scheme is that it has a special ATM cell control block which makes it possible to monitor bursty traffics in real-time so that the delay incurred to measure cell arrival rate is minimized. Additionally, the proposed scheme intends to dynamically reassign the leftover network resources to VBR/ABR connections without any deterioration in quality of service (QoS) of the existing connections. The RITM scheme has been verified to reliably monitor incoming traffics and to efficiently manage network resources by computer simulations. The capability of managing the incoming ATM traffics in real-time helps determine an optimal acceptable number of user connections for a given network condition. We can use this value as a threshold to protect the network from being congested and to find out a cost-effective buffer design method.

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Determining the Flash Flood Warning Trigger Rainfall using GIS (GIS를 활용한 돌발홍수 기준우량 결정)

  • Hwang, Chang-Sup;Jun, Kye-Won;Yeon, In-Sung
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.1
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    • pp.78-88
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    • 2006
  • This paper is to apply Geographical Information System (GIS) supported Geomorphoclimatic Instantaneous Unit Hydrograph (GCIUH) approach for the calculated flash flood trigger rainfall of the mountainous area. GIS techniques was applied in geography data construction such as average slope, drainage area, channel characteristics. Especially, decided stream order using GIS at stream order decision that is important for input variable of GCIUH. We compared the GCIUH peak discharge with the existing report using the design storm at Chundong basin($14.58km^2$). The results showed that derived the GCIUH was a very proper method in the calculation of mountaunous discharge. At the Chundong basin, flash flood trigger rainfall was 12.57mm in the first 20 minutes when the threshold discharge was $11.42m^3/sec$.

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ROC Curve Fitting with Normal Mixtures (정규혼합분포를 이용한 ROC 분석)

  • Hong, Chong-Sun;Lee, Won-Yong
    • The Korean Journal of Applied Statistics
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    • v.24 no.2
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    • pp.269-278
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    • 2011
  • There are many researches that have considered the distribution functions and appropriate covariates corresponding to the scores in order to improve the accuracy of a diagnostic test, including the ROC curve that is represented with the relations of the sensitivity and the specificity. The ROC analysis was used by the regression model including some covariates under the assumptions that its distribution function is known or estimable. In this work, we consider a general situation that both the distribution function and the elects of covariates are unknown. For the ROC analysis, the mixtures of normal distributions are used to estimate the distribution function fitted to the credit evaluation data that is consisted of the score random variable and two sub-populations of parameters. The AUC measure is explored to compare with the nonparametric and empirical ROC curve. We conclude that the method using normal mixtures is fitted to the classical one better than other methods.

Development and Evaluation of an Address Input System Employing Speech Recognition (음성인식 기능을 가진 주소입력 시스템의 개발과 평가)

  • 김득수;황철준;정현열
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.2
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    • pp.3-10
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    • 1999
  • This paper describes the development and evaluation of a Korean address input system employing automatic speech recognition technique as user interface for input Korean address. Address consists of cities, provinces and counties. The system works on a window 95 environment of personal computer with built-in soundcard. In the speech recognition part, the Continuous density Hidden Markov Model(CHMM) for making phoneme like units(PLUs) and One Pass Dynamic Programming(OPDP) algorithm is used for recognition. For address recognition, Finite State Automata(FSA) suitable for Korean address structure is constructed. To achieve an acceptable performance against the variation of speakers, microphones, and environmental noises, Maximum a posteriori(MAP) estimation is implemented in adaptation. And to improve the recognition speed, fast search method using variable pruning threshold is newly proposed. In the evaluation tests conducted for the 100 connected words uttered by 3 males the system showed above average 96.0% of recognition accuracy for connected words after adaption and recognition speed within 2 seconds, showing the effectiveness of the system.

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Standardization for basic association measures in association rule mining (연관 규칙 마이닝에서의 평가기준 표준화 방안)

  • Park, Hee-Chang
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.5
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    • pp.891-899
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    • 2010
  • Association rule is the technique to represent the relationship between two or more items by numerical representing for the relevance of each item in vast amounts of databases, and is most being used in data mining. The basic thresholds for association rule are support, confidence, and lift. these are used to generate the association rules. We need standardization of lift because the range of lift value is different from that of support and confidence. And also we need standardization of support and confidence to compare objectively association level of antecedent variables for one descendant variable. In this paper we propose a method for standardization of association thresholds considering marginal probability for each item to grasp objectively and exactly association level, check the conditions for association criteria and then compare association thresholds with standardized association thresholds using some concrete examples.

A Study on the Improvement of Plastic Boat Manufacturing Process Using TOC & Statistical Analysis (TOC와 통계적 분석에 의한 플라스틱보트 제조공정 개선에 관한 연구)

  • Yoon, Gun-Gu;Kim, Tae-Gu;Lee, Dong-Hyung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.1
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    • pp.130-139
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    • 2016
  • The purpose of this paper is to analyze the problems and the sources of defective products and draw improvement plans in a small plastic boat manufacturing process using TOC (Theory Of Constraints) and statistical analysis. TOC is a methodology to present a scheme for optimization of production process by finding the CCR (Capacity Constraints Resource) in the organization or the all production process through the concentration improvement activity. In this paper, we found and reformed constraints and bottlenecks in plastic boat manufacturing process in the target company for less defect ratio and production cost by applying DBR (Drum, Buffer, Rope) scheduling. And we set the threshold values for the critical process variables using statistical analysis. The result can be summarized as follows. First, CCRs in inventory control, material mix, and oven setting were found and solutions were suggested by applying DBR method. Second, the logical thinking process was utilized to find core conflict factors and draw solutions. Third, to specify the solution plan, experiment data were statistically analyzed. Data were collected from the daily journal addressing the details of 96 products such as temperature, humidity, duration and temperature of heating process, rotation speed, duration time of cooling, and the temperature of removal process. Basic statistics and logistic regression analysis were conducted with the defection as the dependent variable. Finally, critical values for major processes were proposed based on the analysis. This paper has a practical importance in contribution to the quality level of the target company through theoretical approach, TOC, and statistical analysis. However, limited number of data might depreciate the significance of the analysis and therefore it will be interesting further research direction to specify the significant manufacturing conditions across different products and processes.

Effects of the Random Fluctuation in Grating Period on the Characteristics of DFB Lasers (회절격자 주기의 랜덤 변이가 DFB 레이저 특성에 미치는 영향)

  • Han, Jae-Woong;Kim, Sang-Bae
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.8
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    • pp.76-85
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    • 2000
  • Effects of the random fluctuation in grating half-period have been studied by an effective index transfer matrix method in DFB lasers. The laser facets are assumed to be perfectly antireflection coated, and the period fluctuation is modeled as a Gaussian random variable. The random fluctuation breaks spectral symmetry in both uniform-grating and quarter-wavelength -shifted(QWS) DFB lasers, and decreases the effective coupling coefficient. This leads to increased average mirror loss of ${\pm}$1 modes and reduced stopband width in uniform grating DFB lasers, and degradation in the wavelength accuracy and the single mode stability in QWS-DFB lasers. Threshold gain difference decreases with increasing period fluctuation irrespective of grating coupling coefficient in QWS-DFB lasers, while spatial hole-burning effect is exacerbated or alleviated when the normalized coupling coefficient is lower and higher than 1.5, respectively.

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