• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.7
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• pp.1803-1813
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• 1996

This paper describes an automatic threshold decision using a maximum mismatched correlation value in the direct sequence spread spectrum (DS-SS) system. For received PN codes with different single-to-noise ratio (SNR), this scheme is able to detect a desired threshold value in the search mode, i.e. a maximum mismstched correlation value, so that value is utilized as a threshold for the verification mode. Performance of the proposed scheme in both the additive white gaussian noise (AWGN) and frequency-selective Rayleigh fading channels is analyzed through the Monte Carlo simulation. And hardware implementation of this scheme using a DSP processor is demonstrated. The proposed acquisition shceme is compared to the conventional constant threshold (CT) scheme, and significant improvement of performance is shown. Analysis of system performance in the verification mode is presented, and key quantities such as the false alarm probability and the detection probability are derived in a AWGN channel.

• Korean Journal of Forensic Psychology
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• v.13 no.1
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• pp.1-22
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• 2022

This study tested the effect of the verdict category of lay-participation trial in Korea on the legal decision of layperson and the role of representation of 'innocent' in the process. Representation of 'innocent' refers to a psychological threshold for deciding someone's innocence (no fault or sin) in a general sense. The functions as a threshold for a legal decision of 'beyond a reasonable doubt (BRD)' and the individual threshold (IT), regarded as a standard for judgment of guilt established by law and an estimate of an individual's threshold, respectively, were compared. This study used a 2×2 complete factorial design in which the verdict category (guilty/innocent vs. guilty/not guilty) and the defendant's likelihood of guilt (low vs. high) were manipulated. Data from 137 lay-people who voluntarily participated in the online experiment was analyzed. The experiment's procedure was in the order of measuring 'representation of innocent' and the likelihood of guilt of an accused, presenting one of four trial vignettes, and obtaining legal decisions (verdict confidence and estimation of the likelihood of guilt for the defendant). As a result, it was found that the verdict category did not significantly affect the legal decision of layperson. However, the guilty verdict rate of the 'guilty/innocent' condition tended to be higher than those of the 'guilty/not guilty' condition. The layperson's representation of 'innocent' and the verdict category had an interaction effect on the difference between BRD and IT (threshold change) at the significance level of .1. In the 'guilty/innocent' condition, the threshold change varying with layperson's representation of 'innocent' was larger than in the 'guilty/not guilty' condition. In comparing the function of BRD and IT, IT significantly predicted the lay person's legal decision at the significance level of .1 by interacting with the likelihood of guilt for the defendant. Therefore, it could be said that IT was a better threshold estimator than BRD. The implication of this study is that it provided experimental evidence for the effect of the verdict category of lay-participation trial in Korea, which is a problem often raised among lawyers, and suggested logical reasoning and empirical grounds for the psychological mechanism of the possible effect.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.17-22
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• 2016

For the self-adaptive equalization of higher-order QAM systems, this paper proposes a new soft decision-directed (SDD) algorithm that opens the eye patterns quickly as well as significantly reducing the error level in the steady-state when it is applied to the initial equalization stage with completely closed eye patterns. The proposed method for M-QAM application minimized the computational complexity of the existing SDD by the symbol estimated based on the two symbols closest to the observation, and greatly simplified the soft decision independently of the QAM order. Furthermore, in the symbol estimating it increased the reliability of the estimates by applying the superior properties of the sigmoid function and avoiding the erroneous estimation of the threshold function. In addition, the initialization performance was improved when an error is generated to update the equalizer, weighting the symbol decision by the threshold function to the error, resulting in an extension of the range of error fluctuations. As a result, the proposed method improves remarkably the computational complexity and the properties of initialization and convergence of the traditional SDD. Through simulations for 64-QAM and 256-QAM under multipath channel conditions with additive noise, the usefulness of the proposed methods was confirmed by comparing the performance of the proposed 2-SDD and two forms of weighted 2-SDD with CMA.

• Journal of the Korean Institute of Telematics and Electronics
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• v.12 no.1
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• pp.1-6
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• 1975

The boundary has been one of the most important information in radiographic images and the degrees of difficulty involved varies greatly with the quality of the picture. These Buantifications are the means to diagnoses. The purpose of this paper is to quantify intensity variation and the threshold decision which is based on statistical principles and is developed to detect limits in liver scintigrams the entire picture is devide4 into 64 small regions. The kurtosis and variances for each smal region are used as indications to select the histograms the thresholds are computed according to the method o(maximum likelihood which minimizes the probability o( misclassification. Therefore Ive have demonstrated the applicability of the boundary detection and proved good agreement with human recognition, and we can use it for the diagnosis data of liver disease.

• Journal of the Korea Society of Computer and Information
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• v.12 no.6
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• pp.167-175
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• 2007

Fuzzy logic is used to represent qualitative knowledge and provides interpretability to a controlling system model in bioinformatics. This paper focuses on a bioinformatics data classification which is an important bioinformatics application. This paper reviews the two traditional controlling system models The sequence-based threshold controller have problems of optimal range decision for threshold readjustment and long processing time for optimal threshold induction. And the binary-based threshold controller does not guarantee for early system stability in the GPCR data classification for optimal threshold induction. To solve these problems, we proposes a fuzzy-based threshold controller for ART1 clustering in GPCR classification. We implement the proposed method and measure processing time by changing an induction recognition success rate and a classification threshold value. And, we compares the proposed method with the sequence-based threshold controller and the binary-based threshold controller The fuzzy-based threshold controller continuously readjusts threshold values with membership function of the previous recognition success rate. The fuzzy-based threshold controller keeps system stability and improves classification system efficiency in GPCR classification.

• Korean Management Science Review
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• v.27 no.1
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• pp.33-43
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• 2010

This paper presents a method for the estimation and analysis of the economic value of weather forecasts for CRM decision-making problems in the leisure industry. Value is calculated in terms of the customer's satisfaction returned from the user's decision under the specific payoff structure, which is itself represented by a customer's satisfaction ratio model. The decision is assessed by a modified cost-loss model to consider the customer's satisfaction instead of the loss or cost. Site-specific probability and deterministic forecasts, each of which is provided in Korea and China, are applied to generate and analyze the optimal decisions. The application results demonstrate that probability forecasts have greater value than deterministic forecasts, provided that the users can locate the optimal decision threshold. This paper also presents the optimal decision strategy for specific customers with a variety of satisfaction patterns.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.85-94
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• 2009

In this work we propose an energy-efficient transmission strategy for wireless sensor networks that operate in a strict energy-constrained environment. Our transmission algorithm consists of two components: a binary-decision based transmission and a channel-aware backoff adjustment. In the binary-decision based transmission, we obtain the optimum threshold for successful transmission via Markov decision process (MDP) formulation. A channel-aware backoff adjustment, the second component of our proposal, is introduced to favor sensor nodes seeing better channel in terms of transmission priority. Extensive simulations are performed to verify the performance of our proposal over fading wireless channels.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.4
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• pp.406-414
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• 1997

A real-time inspection system is developed using line scan cameras. Several improved algorithms are proposed for real-time detection of defects in this automated inspection system. The major improved algorithms include the preprocessing, the threshold decision, and the clustering algorithms. The preprocessing algorithms are for exact binarization and the threshold decision algorithm is for fast detection of defects in 1-D binary images. The clustering algorithm is also developed for fast classifying of the defects. The system is applied to PCBs(Printed Circuit Boards) inspection. The typical defects in PCBs are pits, dent, wrinkle, scratch, and black spots. The results show that most defects are detected and classified successfully.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.9-13
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• 1994

The Heat Anisotropic Diffusion Method has shown very effective for the contour detection of 2-D echocardiogram. To implement this algorithm, we have to choose the parameter C, K, and the threshold level. The choice of C and K are not very sensitive for the good edge detection of the echocardiogram, however the choice of the threshold level is very critical. Until now the threshold level is chosen by the trial and error method. In this paper, we present an automatic threshold decision method from the histogram of the gradient of boundary-like pixels.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.37-42
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• 2003

Threshold signature and blind signature are playing important roles in cryptography as well as practical applications such as e-cash and e-voting systems. In this paper, we present a new threshold blind digital signature based on pairings without a trusted third party. Our scheme operates on Gap Diffie-Hellman group, where Computational Diffie-Hellman problems are hard but Decision Diffie-Hellman problems are easy. For example, we use pairings that could be built from Weil pairing or Tate pairing. To the best of our knowledge, we claim that our scheme is the first threshold blind signature using pairings with provable security in the random oracle model.