• Journal of the Korean Statistical Society
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• v.26 no.4
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• pp.493-505
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• 1997

The analysis of binary data appears to many areas such as statistics, biometrics and econometrics. In many cases, data are often collected in which some observations are incomplete. Assume that the missing covariates are missing at random and the responses are completely observed. A method to Bayesian analysis of the binary regression model with incomplete data is presented. In particular, the desired marginal posterior moments of regression parameter are obtained using Meterpolis algorithm (Metropolis et al. 1953) within Gibbs sampler (Gelfand and Smith, 1990). Also, we compare logit model with probit model using Bayes factor which is approximated by importance sampling method. One example is presented.

• Journal of the Korean Data and Information Science Society
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• v.19 no.4
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• pp.1429-1440
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• 2008

In a meta-analysis combining the results from different clinical trials, it is important to consider the possible heterogeneity in outcomes between trials. Such variations can be regarded as random effects. Thus, random-effect models such as HGLMs (hierarchical generalized linear models) are very useful. In this paper, we propose a HGLM framework for analyzing the binominal response data which may have variations in the odds-ratios between clinical trials. We also present the prediction intervals for random effects which are in practice useful to investigate the heterogeneity of the trial effects. The proposed method is illustrated with a real-data set on 22 trials about respiratory tract infections. We further demonstrate that an appropriate HGLM can be confirmed via model-selection criteria.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.762-765
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• 2005

본 연구에서는 유도 진동기의 파워 스펙트럼의 확산을 위한 LF2470 DSP기반 Hybrid Random PWM을 제안하였다. 제안된 방법은 Lead-Lag 랜덤 비트를 발생하기 위한 PRBS (Pseudo-Random Binary Sequence)와 PRBS와 논리적 비교를 위한 삼각파 랜덤 캐리어로 이루어진다. 또한 DSP에 의하여 랜덤 수 및 PRBS 그리고 3상 기준 정현파를 실시간으로 발생하며, DSP외부의 주파수 변조기 MAX038에 의하여 랜덤 주파수의 캐리어를 발생한다. 본 연구의 타당성 검증을 위하여 제안된 기법을 3상 유도전동기 구동장치에 적용하였으며, 종전의 방법과 전압 및 전류 그리고 전동기 소음 스펙트럼을 비교 검토하였다.

• KIPS Transactions on Computer and Communication Systems
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• v.9 no.5
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• pp.101-106
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• 2020

Since computer became available, much effort has been made to achieve information security. Even though memory protection defense mechanisms were studied the most among of them, the problems of existing memory protection defense mechanisms were found due to improved performance of computer and new defense mechanisms were needed due to the advent of the side-channel attacks. In this paper, we propose JMP+RAND that embedding random values of 5 to 8 bytes per page to defend against memory sharing based side-channel attacks and bridging the gap of existing memory protection defense mechanism. Unlike the defense mechanism of the existing side-channel attacks, JMP+RAND uses static binary rewriting and continuous jmp instruction and random values to defend against the side-channel attacks in advance. We numerically calculated the time it takes for a memory sharing-based side-channel attack to binary adopted JMP+RAND technique and verified that the attacks are impossible in a realistic time. Modern architectures have very low overhead for JMP+RAND because of the very fast and accurate branching of jmp instruction using branch prediction. Since random value can be embedded only in specific programs using JMP+RAND, it is expected to be highly efficient when used with memory deduplication technique, especially in a cloud computing environment.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.273-273
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• 2000

We present a new scheme to increase the performance of edge-preserving image smoothing from the parameter tuning of a Markov random field (MRF) function. The method is based on automatic control of the image smoothing-strength in MRF model ing in which an introduced parameter function is based on control of enforcing power of a discontinuity-adaptive Markov function and edge magnitude resulted from discontinuities of image intensity. Without any binary decision for the edge magnitude, adaptive control of the enforcing power with the full edge magnitude could improve the performance of discontinuity-preserving image smoothing.

• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.157-160
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• 2005

본 연구에서는 고정 주파수의 캐리어 합성만으로 랜덤 주파수의 캐리어를 간단하게 발생하는 방법을 제안하였다. 고정 주파수를 갖는 삼각파 캐리어와 그 역상의 삼각파 캐리어를 랜덤 비트 발생기(PRBS : Pseudo Random Binary Sequence)에 의하여 선택하여 랜덤 주파수 캐리어를 새롭게 합성 할 수 있다. 실험과 시뮬레이션에 의하여 PRBS의 시트프 레지스터의 비트별 고조파 스펙트럼을 비교 고찰하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.3
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• pp.110-116
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• 2008

In this paper, we proposed an improvement technique of image encryption using binary phase computer generated hologram(BPCGH) and multi exclusive-OR(XOR) operations. For the encryption process, a BPCGH that reconstructs the original image is designed, using an iterative algorithm, and the resulting hologram is regarded as the image to be encrypted. The BPCGH is encrypted through the exclusive-OR operation with the random generated phase key image. Then the encrypted image is divided into several slide images using XOR operations. So, the performance of encryption for the image is improved. For the decryption process, we cascade the encrypted slide images and phase key image and interfere with reference wave. Then decrypted hologram image is transformed into phase information. Finally, the original image is recovered by an inverse Fourier transformation of the phase information. If the slide images are changed, we can get various decrypted BPCGH images. In the proposed security system, without a random generated key image, the original image can not be recovered. And we recover another hologram pattern according to the slide images, so it can be used in the differentiated authorization system.

• The Korean Journal of Applied Statistics
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• v.32 no.2
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• pp.291-300
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• 2019

This study investigates the characteristics of evaluation measures for classification models on a binary response variable in order to evaluate their suitability for use. Six measures are considered: Accuracy, Sensitivity, Specificity, Precision, F-measure, and the Heidke's skill score (HSS). Evaluation measures are reformulated using x(ratio of actually 1), y(ratio predicted by 1), z(ratio of both actual and predicted by 1) from the confusion matrix. We suggest two necessary conditions to assess the suitability of the evaluation measures. The first condition is that the measure function is constant for x and y in the case of a random model. The second condition is that the measure function is increasing for z and decreasing for x and y. Since only HSS satisfies the two conditions, that is always appropriate as an evaluation measure for the classification model on the binary response variable, and the other measures should be used within a limited range.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.10a
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• pp.365-368
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• 2005

이동중인 단말에게 인터넷 서비스를 제공하고자 하는 WiBro 시스템은, 무선자원의 효율적인 사용을 위해서 전송할 데이터가 있는 단말들에게만 대역폭을 할당하는 demand-based 대역폭 할당 방식을 사용한다. 이때 여러 단말들이 동시에 데이터를 전송하고자할 경우 충돌이 발생하므로 이들의 전송순서를 정해주는 것이 필요하다. 기존의 WiBro 시스템에서는 binary exponential backoff algorithm 에 기초한 random access 기법을 사용하는데, 본 연구에서는 conflict resolution 기법에 기초한 새로운 random access 기법을 제안하고, 새로운 기법의 성능이 보다 우수함을 시뮬레이션을 통해 보였다.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.10
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• pp.513-519
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• 2001

This paper proposed a random sigma-delta modulator(RSDM), which is constructed by a 1st order sigma-delta modulator(SDM) and a simple structured random binary generator(RBG). The 1st order SDM produces a switching pulse waveform which has the same low-frequency component as the reference input, while the RBG spreads the distribution of the number of sampling per switching cycle, and thus disperses the spectrum spikes in the output. The relationship between the harmonic spectra and the number of sampling per switching cycle is studied through computer simulations, and the frequency spectra of the RSDM are confirmed in an experimental setup.