• 디지털융복합연구
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• 제17권7호
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• pp.59-71
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• 2019

유통물류센터는 재고를 보유하고 있어 효율적인 보관면적에 관한 설계는 매우 중요하다. 이에 본 연구는 표준 파렛트 유닛로드 이용을 고려한 유통물류센터의 최적 보관면적 산출방안 제시를 연구 목적으로 하며, 연구결과는 다음과 같다. 첫째, 국내에서 주로 사용되는 T-11형과 T-12형 파렛트를 보관하는 표준 랙 모듈을 정의하였다. 둘째, 다양한 파렛트 운반 장비를 조사 및 분석하여, 유형별 표준 운반장비 작업통로를 정의하였다. 그리고 최종으로 보관 공간 내에서 랙 모듈 배치 시 발생할 수 있는 비활용 공간 최소화 방안 제시와 함께 유통물류센터 보관 공간에 대한 손쉬운 최적면적 산출 방안을 제안하였다는 측면에서 큰 시사점을 갖는다. 향후 연구에서는 Mini-Load용 표준 랙 모듈 및 GTP(Goods to Person) 피킹 시스템 등 최근 물류 기술이 반영된 표준화된 전체 물류센터 레이아웃 배치에 관한 연구가 필요하다.

• International Journal of Reliability and Applications
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• 제4권3호
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• pp.97-111
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• 2003

By applying Theorem 2.6.4 (Fang and Zhang, 1990, p.66) the dispersion matrix of a multivariate power exponential (MPE) distribution is derived. It is shown that the MPE and the gamma distributions are related and thus the MPE and chi-square distributions are related. By extending Fang and Xu's Theorem (1987) from the normal distribution to the Univariate Power Exponential (UPE) distribution an explicit expression is derived for calculating the probability of an UPE random variable over an interval. A representation of the characteristic function (c.f.) for an UPE distribution is given. Based on the MPE distribution the probability density functions of the generalized non-central chi-square, the generalized non-central t, and the generalized non-central F distributions are derived.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.401-403
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• 2002

Transmission and Distribution(T&D) pricing has been one of keystones of ongoing deregulation and privatization process in power industries. The electricity markel has been established based on open access and nondiscriminatory use of the T&D assets. As T&D business remains as a monopoly, it is necessary to provide economic regulation. This paper focuses on the distribution pricing methods and the analysis of pricing structure of distribution-retail sale company under power system deregulation.

• 충청수학회지
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• 제22권3호
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• pp.519-524
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• 2009

In multivariate analysis, the inversion formula of the Stieltjes transform is used to find the density of a spectral distribution of random matrices of sample covariance type. Let $B_{n}\;=\;\frac{1}{n}Y_{m}^{T}T_{m}Y_{m}$ where $Ym\;=\;[Y_{ij}]_{m{\times}n}$ is with independent, identically distributed entries and $T_m$ is an $m{\times}m$ symmetric nonnegative definite random matrix independent of the $Y_{ij}{^{\prime}}s$. In the present paper, using the inversion formula of the Stieltjes transform, we will find the density function of the limiting distribution of $B_n$ away from zero.

• Communications for Statistical Applications and Methods
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• 제21권6호
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• pp.501-512
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• 2014

Stylized facts on asset return are fat-tail, asymmetry, volatility clustering and structure changes. This paper simultaneously captures these characteristics by introducing a multi-regime models: Finite mixture distribution and regime switching GARCH model. Analyzing the daily KOSPI return from $4^{th}$ January 2000 to $30^{th}$ June 2014, we find that a two-component mixture of t distribution is a good candidate to describe the shape of the KOSPI return from unconditional and conditional perspectives. Empirical results suggest that the equality assumption on the shape parameter of t distribution yields better discrimination of heterogeneity component in return data. We report the strong regime-dependent characteristics in volatility dynamics with high persistence and asymmetry by employing a regime switching GJR-GARCH model with t innovation model. Compared to two sub-samples, Pre-Crisis (January 2003 ~ December 2007) and Post-Crisis (January 2010 ~ June 2014), we find that the degree of persistence in the Pre-Crisis is higher than in the Post-Crisis along with a strong asymmetry in the low-volatility (high-volatility) regime during the Pre-Crisis (Post-Crisis).

• Journal of Magnetics
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• 제22권1호
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• pp.1-6
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• 2017

Magnetic properties of CoPt nanoparticles (average size = 2.1 nm) encapsulated in synthesized protein shell have been investigated with SQUID (Superconducting Quantum Interference Device) magnetometer and analyzed by the recently developed non-equilibrium magnetization calculation by our group [T. H. Lee et al., Phys. Rev. B 90, 184411 (2014)]. Field dependence of magnetization measured at 2 K was successfully analyzed with modified Langevin function. In addition, small hysteresis loops having the coercive field of 890 Oe were observed at 2 K. Temperature dependence of magnetization has been measured with zero field cooled (ZFC) and field cooled (FC) protocol with slightly modified sequence in accordance with non-equilibrium magnetization calculation. The analysis on the M vs. T data revealed that the anisotropy energy barrier distribution is found to be very different from the log-normal distribution found in a size distribution. Zero temperature coercive field and Bloch coefficient have also been extracted from the analysis and the validity of those values is checked.

• Journal of the Korean Physical Society
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• 제73권9호
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• pp.1230-1239
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• 2018

We derive a factorization theorem for the jet mass distribution with a given $p^J_T$ for the inclusive production, where $p^J_T$ is a large jet transverse momentum. Considering the small jet radius limit ($R{\ll}1$), we factorize the scattering cross section into a partonic cross section, the fragmentation function to a jet, and the jet mass distribution function. The decoupled jet mass distributions for quark and gluon jets are well-normalized and scale invariant, and they can be extracted from the ratio of two scattering cross sections such as $d{\sigma}/(dp^J_TdM^2_J)$ and $d{\sigma}/dp^J_T $. When $M_J{\sim}p^J_TR$, the perturbative series expansion for the jet mass distributions works well. As the jet mass becomes small, large logarithms of $M_J/(p^J_TR)$ appear, and they can be systematically resummed through a more refined factorization theorem for the jet mass distribution.

• Restorative Dentistry and Endodontics
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• 제18권2호
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• pp.317-340
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• 1993

This study was designed 1) to compare the distributions of periapical inflammatory cells and 2) to identify lymphocytes and compare the lymphocyte distribution with T lymphocyte subpopulation and then 3) to examine the distribution of cycling cell in human dental periapical lesions. From each of the twenty-five human dental periapical lesions observed one small portion was fixed, embeded in paraffin, sectioned serially and stained with HE. The periapical inflammatory cells were counted to obtain the relative concentration of lymphocyte, plasma cell, macrophage and neutrophil. The large part of each lesion was analysed using Flow cytometer and monoclonal antibodies to obtain the relative concentration of T lymphocyte, B lymphocyte, T'helper cell and T suppressor/cytotoxic cell. In addition to that, seven human dental periapical lesions were examined with DNA analysis to observe the distribution of cycling cell. Following results were obtained: 1. 24 cases of the 32 periapical lesions examined were diagnosed as periapical granuloma and the remaining 8 cases as periapical cyst. Lymphocytes comprised 42.1% of total inflammatory cells in periapical granuloma and 41.8% in periapical cyst. Corresponding percentages for macrophages were 33.8% and 30.3%; for plasma cells, 15.9% and 19.0%; for neutrophils, 8.2% and 8.8%. 2. All of the periapical lesions examined had T lymphocyte, B lymphocyte, T helper cell, T suppressor/cytotoxic cell. And in all cases, T lymphocytes were observed predominantly more than B lymphocytes. 3. In 2 cases of the control group only T lymphocytes were found, and in the remaining 2 cases T lymphocytes were observed predominantly. 4. T helper cells were observed predominantly more than T suppressor/cytotoxic cells in all cases of perapical granulomas. 5. T suppressor/cytotoxic cells were observed predominantly more than T helper cells in 4 cases of periapical cysts (total 5 cases were examined) and only in one case T helper cells were more than T suppressor/cytotoxic cells. 6. In control group, T helper cells were predominant in 2 cases and T helper cells were equivalent to T suppressor/cytotoxic cells in one case. In remaining one case T suppressor/cytotoxic cells were predominant. 7. As the result of DNA analysis, the average proliferating indices of the various groups examined were measured as follows: in the control group 5.45%, in periapical granuloma 6.64%, in periapical cyst 10.1%. The highest index was observed in periapical cyst.

• Journal of the Korean Statistical Society
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• 제24권2호
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• pp.471-479
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• 1995

A random shock model for a linearly deteriorating system is introduced. The system deteriorating linearly with time is subject to random shocks which arrive according to a Poisson process and decrease the state of the system by a random amount. The system is repaired by a repairmen arriving according to another Poisson process if the state when he arrives is below a threshold. Explicit expressions are deduced for the characteristic function of the distribution function of X(t), the state of the system at time t, and for the distribution function of X(t) if X(t) is over the threshold. The stationary case is briefly discussed.

• 품질경영학회지
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• 제25권3호
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• pp.11-21
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• 1997

The mean residual life(MRL) function gives the expected remaining life of a item at age t. In particular F is said to be an increasing intially then decreasing MRL(IDMRL) distribution if there exists a turing point $t^*\ge0$ such that m(s)$\le$ m(t) for 0$$\le s$\le$ t $t^*$, m(s)$\ge$ m(t) for $t^*\le$ s$\le$ t. If the preceding inequality is reversed, F is said to be a decreasing initially then increasing MRL(DIMRL) distribution. Hawkins, et al.(1992) proposed test of H0 : F is exponential versus$H_1$: F is IDMRL, and $H_0$ versus $H_1$' : F is DIMRL when turning point is unknown. Their test is based on a complete random sample $X_1$, …, $X_n$ from F. In this paper, we generalized Hawkins-Kochar-Loader test to random censored data.