• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.514-519
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• 1992

To make an accurate retrieval of the proportion of each category among mixed pixels (Mixel's) of a remotely sensed imagery, a maximum likelihood estimation method of category proportion is proposed. In this method, the observed multispectral vector is considered as probability variables along with the approximation that the supervised data of each category can be characterized by normal distribution. The results show that this method can retrieve accurate proportion of each category among Mixel's. And a index that can estimate the degree of error in each category is proposed. AS one of the application of the proportion estimation, a method for image classification based on category proportion estimation is proposed. In this method all pixel in a remotely sensed imagery are assumed to be Mixel's, and are classified to most dominant category. Among the Mixel's, there exists unconfidential pixels which should be categorized as unclassified pixels. In order to discriminate them, two types of criteria, Chi square and AIC, are proposed for fitness test on pure pixel hypothesis. Experimental result with a simulated dataset show an usefulness of proposed classification criterion compared to the conventional maximum likelihood criterion and applicability of the fitness tests based on Chi square and AIC,

• 한국통신학회논문지
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• 제39C권9호
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• pp.852-860
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• 2014

본 논문에서 임펄스성 잡음의 유무를 검증하는 알고리즘을 제안한다. 본 알고리즘을 제안하는 이유는 기존의 Kolmogorov-Smirnov 검증의 단점으로 낮은 분류 성공률 및 높은 복잡도가 있기 때문이다. 이는 이론적으로 문제가 없으나 실제로 구현함에 있어 많은 문제를 야기한다. 먼저 기존의 검증 방법을 설명 후 제안하는 알고리즘을 설명한다. 이 알고리즘은 기존의 Kolmogorov-Smirnov 검증 방법의 이론적 배경으로부터 제안된다. 알고리즘의 효율성을 증명하기 위해 임펄스성 잡음의 샘플을 이용하여 실험 후, 검증 실패 확률을 조사한다. 검증 실패 확률에 기반한 실험 결과는 제안한 알고리즘의 효율성을 증명한다.

• ETRI Journal
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• 제33권2호
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• pp.219-229
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• 2011

In this paper, we propose a transformation scheme used to analyze online gaming traffic properties and develop a traffic model. We analyze the packet size and the inter departure time distributions of a popular first-person shooter game (Left 4 Dead) and a massively multiplayer online role-playing game (World of Warcraft) in order to compare them to the existing scheme. Recent online gaming traffic is erratically distributed, so it is very difficult to analyze. Therefore, our research focuses on a transformation scheme to obtain new smooth patterns from a messy dataset. It extracts relatively heavy-weighted density data and then transforms them into a corresponding dataset domain to obtain a simplified graph. We compare the analytical model histogram, the chi-square statistic, and the quantile-quantile plot of the proposed scheme to an existing scheme. The results show that the proposed scheme demonstrates a good fit in all parts. The chi-square statistic of our scheme for the Left 4 Dead packet size distribution is less than one ninth of the existing one when dealing with erratic traffic.

• The Journal of Asian Finance, Economics and Business
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• 제8권12호
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• pp.85-94
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• 2021

Infrastructure capacities are essential elements and one of the sustainable lines to drive economic growth. Infrastructure development, both physical and social, is vital to sector-wise economic development. However, there is limited evidence of how infrastructure development in certain sectors benefits the economy as a whole. This study explains the relationships between infrastructure and economic growth in selected middle-income Asian countries, highlighting the essential criteria to benefit from both physical and social infrastructure, as well as sectoral (agriculture, industry, and services) economic output. The research uses the data from 1990 to 2020 for empirical estimations. The study used Levin, Lin, & Chu test, ADF- Fischer chi- Square, and PP- Fischer Chi-Square to test unit root and to observe the stationary nature of the panel. Padroni and Kao cointegration is applied to check the cointegration among different panes. A Fully Modified OLS was employed for checking the association between physical and social infrastructure and economic growth. Results show that physical and social infrastructure negatively impact sectoral output in Asia's middle-income countries. Apart from infrastructure the per capita GDP growth, tax to GDP ratio, and population growth shows a simultaneous relation between infrastructure and sectoral economic growth.

• 한국조리학회지
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• 제19권5호
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• pp.11-22
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• 2013

본 연구는 고등학생을 대상으로 한 학교급식의 서비스 품질속성, 급식 이미지 및 급식만족에 대한 영향관계를 규명하고 배식형태의 조절효과를 알아보았다. 연구 가설을 검증하기 위하여 통계 프로그램 SPSS 18.0, AMOS 18.0을 활용하여 빈도분석, 요인분석, 신뢰도 분석, 요인분석, 경로분석 및 카이제곱 적합성 검증을 실시하였다. 분석결과, 요인적재값이 0.4이상이고, ${\chi}^2$=258.831, d.f.=98, RMR=0.059, GFI=.884, AGFI=.839, NFI=0.908, IFI=0.941, CFI=0.940으로 척도가 타당도와 신뢰도가 있음을 보여 주었다. 가설검증을 위하여 구조 모형분석을 실시, 첫째, 급식 서비스품질은 급식이미지에 유의한 영향을 미칠 것으로 나타나 4개의 하위가설 모두 채택되었다. 둘째, 급식이미지는 급식만족에 유의한 영향을 미치는 것으로 나타났고 셋째, 급식이미지와 급식만족과의 관계에서 배식형태에 따른 조절효과가 있는 것으로 나타났다.

• 호남수학학술지
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• 제26권2호
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• pp.219-236
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• 2004

In this paper, the problem of estimating a p-variate ($p{\geq}4$) normal mean vector is considered in a decision-theoretic setup. Using a simple property of the noncentral chi-square distribution, a sequence of smooth estimators dominating the Lindley type estimator has been produced and each improved estimator is better than previous one.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1489-1492
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• 1997

To increase reliability and performance of an IMS(Intelligent Manufacturing System), fault tolerant control based on an accurate fault diagnosis is needed. In this paper, robot FDI(fault detection and identification) is proposed for IMS where the robot is controlled with state estimates of a nonlinear filter using a mathematical robot model. The Chi-square distribution is applied fault detection and fault size is estimated by a proposed bias filter. Performance of the proposed algorithm is tested by simulation for studies.

• 대한산업공학회지
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• 제14권1호
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• pp.51-56
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• 1988

A spectrum analysis method is presented with an example as an aid to Box and Jerkins' model identification procedure, where the theoretical spectrum of ARMA model and its confidence intervals derived by chi-square distribution are compared. An APL (A Programming Language) program for the method is developed for the 16-bit personal computer.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.525-534
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• 2003

If a restriction is imposed only to a (proper) subset of parameters of interest, we call it a local restriction. Statistical inference under a local restriction in multinomial setting is studied. The maximum likelihood estimation under a local restriction and likelihood ratio tests for and against a local restriction are discussed. A real data is analyzed for illustrative purpose.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 추계 학술발표회 논문집
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• pp.79-83
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• 2002

A phase III clinical trial of a new drug for neutropenia induced by chemotherapy is presented and consider adding random effects in crossover design which was used in the clinical study. The diagnostics for its heteroscedasticity based on score statistic is derived for detecting homoscedasticity of errors in crossover design. A small simulation study is peformed to investigate the finite sample behaviour of the test statistic which is known to have an asymptotic chi-square distribution under the null hypothesis.