• 조명전기설비학회논문지
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• 제13권4호
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• pp.82-86
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• 1999

본 연구에서는 푸로브법과 교류중첩법을 이용하여 고주파 유도결합 플라즈마에서 전자에너지 분포함수를 측정하였다. 실험조건은 압력 10∼40[mTorr], 입력파워는 100∼600[W]이고, 가스유량은 3∼12[sccm]이며, 전자에너지 분포함수의 공간분포 측정에 있어서 아스펙트비(R/L)는 2로 하였다. 전자에너지 분포함수는 압력 및 입력파워에 대하여 강한 의존성을 나타내었고, 가스유량이 증가할수록 증가 하였다. 전자에너지 분포함수의 반경방향 분포는 플라즈마 중심에서 최대가 되었다. 전자에너지 분포함수의 축방향 분포는 석영창과 기판 사이의 중심에서 최대가 되었다. 이러한 결과는 고주파 유도결합 플라즈마의 생성 메커니즘 이해와 간단한 ICP(Inductively Coupled Plasma) 모델링 응용에 기여할 수 있을 것이다.

• 설비공학논문집
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• 제23권5호
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• pp.365-374
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• 2011

For the first time, the present study has measured the velocity distribution function in circular open channel flow in a three-dimensional shape using a stereoscopic PIV system. For a given channel slope, water depth was varied from 30% to 80% of the channel diameter. Then, the characteristics of the velocity distribution function was compared according to the change of the water depth. Unlike a rectangular channel, the present experiment exhibited quite different shapes in the velocity distribution function whether the water depth is higher than 50% or not. Especially, the position of maximum velocity in the central and side wall changes in a different manner for the water depth above 50%. By differentiating the velocity distribution function, local wall friction coefficient was evaluated as a function of wall position. If the water depth goes down, the difference between the maximum and minimum values in the local wall friction coefficient increases, and the averaged value a1so increases.

• 경영과정보연구
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• 제17권
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• pp.67-81
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• 2005

Harbor function has been changed into physical distribution position harbor system for providing most suitable physical distribution service with comprehensive rationalization of international physical distribution over simple loading unloading, and change function by far. Thus, to change our country into advanced economy, the factor of growth obstacles was to be eliminated, or it is so important that the physical distribution base establishment enlarges to improve potential productivity. That is, self effort is needed for physical distribution competition system, adjustable arrangement of physical distribution area, the establishment of comprehensive informations system, physical distribution rationalization. Also, to enforce harbor productivity, harbor should be developed systemically to able to function of comprehensive harbor for enlargement of harbor establishment, the device of advanced harbor function height, the linkage between and city program, harbor operation or investment system provement, harbor technique or international cooperation advancement.

• Journal of the Korean Statistical Society
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• 제36권1호
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• pp.93-109
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• 2007

Gamma distributions are some of the most popular models for hydrological processes. In this paper, a very flexible family which contains the gamma distribution as a particular case is introduced. Evidence of flexibility is shown by examining the shape of its pdf and the associated hazard rate function. A comprehensive treatment of the mathematical properties is provided by deriving expressions for the nth moment, moment generating function, characteristic function, Renyi entropy and the asymptotic distribution of the extreme order statistics. Estimation and simulation issues are also considered. Finally, a detailed application to drought data from the State of Nebraska is illustrated.

• 한국정보통신학회논문지
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• 제18권5호
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• pp.1143-1148
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• 2014

본 연구에서는 비대칭 이중게이트 MOSFET의 채널 내 도핑분포함수의 변화에 따른 문턱전압이하 스윙의 변화를 분석하였다. 이중게이트 MOSFET의 특성을 결정하는 가장 기본적인 요소는 채널의 크기 즉, 채널길이, 채널두께 등과 채널의 도핑분포함수이다. 도핑분포는 채널도핑 시 사용하는 이온주입법에 의하여 결정되며 일반적으로 가우스분포함수에 준한다고 알려져 있다. 포아송방정식을 이용하여 전하분포를 구하기 위하여 가우스분포함수을 이용하였다. 가우스분포함수는 반드시 상하 대칭이 아니므로 채널길이 및 채널두께, 그리고 비대칭 이중게이트 MOSFET의 상하단 게이트 전압 변화 등에 따라 문턱전압이하 스윙 값은 크게 변화할 것이다. 이에 본 연구에서는 가우스분포함수의 파라미터인 이온주입범위 및 분포편차에 따른 문턱전압이하 스윙의 변화를 관찰하고자 한다. 분석결과, 문턱전압이하 스윙은 도핑분포함수 및 게이트 전압 등에 따라 크게 영향을 받는 것을 관찰할 수 있었다.

• Communications for Statistical Applications and Methods
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• 제23권5호
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• pp.399-409
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• 2016

Many of studies have suggested the modifications on Weibull distribution to model the non-monotone hazards. In this paper, we combine two cumulative hazard functions and propose a new modified Weibull distribution function. The newly suggested distribution will be named as a new flexible Weibull distribution. Corresponding hazard function of the proposed distribution shows flexible (monotone or non-monotone) shapes. We study the characteristics of the proposed distribution that includes ageing behavior, moment, and order statistic. We also discuss an estimation method for its parameters. The performance of the proposed distribution is compared with existing modified Weibull distributions using various types of hazard functions. We also use real data example to illustrate the efficiency of the proposed distribution.

• Journal of the Korean Data and Information Science Society
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• 제11권2호
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• pp.303-312
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• 2000

We compare the MLE, UMVUE and Jackknife Estimators for the reliability function of the weibull distribution when the sample size is small.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제16권2호
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• pp.179-186
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• 2009

Generalizing the approximately convex function which is introduced by D.H. Hyers and S.M. Ulam we establish an approximately convex Schwartz distribution and prove that every approximately convex Schwartz distribution is an approximately convex function.

• Nonlinear Functional Analysis and Applications
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• 제28권3호
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• pp.793-800
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• 2023

In this paper, we propose a generalization of Lindley distribution (GLD) via a special structure that is concern with progressively Type-II right censoring and time failure data. We study the modern properties that we have built by such combination, for example, survival function, hazard function, moments, and estimation by non-Bayesian methods. Application on some selected data related to Lindley distribution (LD) and (ED) have been employed to find out the best distribution that can fit data comparing with the GLD.

• 제어로봇시스템학회논문지
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• 제20권8호
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• pp.854-867
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• 2014

This paper deals with the performance comparison of a PSO algorithm inspired in the process of simulating the behavior pattern of the organisms. The PSO algorithm finds the optimal solution (fitness value) of the objective function based on a stochastic process. Generally, the stochastic process, a random function, is used with the expression related to the velocity included in the PSO algorithm. In this case, the random function of the normal distribution (Gaussian) or uniform distribution are mainly used as the random function in a PSO algorithm. However, in this paper, because the probability distribution which is various with 2 shape parameters can be expressed, the performance comparison of a PSO algorithm using the beta probability distribution function, that is a random function which has a high degree of freedom, is introduced. For performance comparison, 3 functions (Rastrigin, Rosenbrock, Schwefel) were selected among the benchmark Set. And the convergence property was compared and analyzed using PSO-FIW to find the optimal solution.