• The KIPS Transactions:PartD
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• v.16D no.3
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• pp.339-352
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• 2009

There are a number of formal methods for distributed real-time systems in ubiquitous computing to analyze and verify the behavioral, temporal and the spatial properties of the systems. However most of the methods reveal structural and fundamental limitations of complexity due to mixture of spatial and behavioral representations. Further temporal specification makes the complexity more complicate. In order to overcome the limitations, this paper presents a new formal method, called Timed Calculus of Abstract Real-Time Distribution, Mobility and Interaction(t-CARDMI). t-CARDMI separates spatial representation from behavioral representation to simplify the complexity. Further temporal specification is permitted only in the behavioral representation to make the complexity less complicate. The distinctive features of the temporal properties in t-CARDMI include waiting time, execution time, deadline, timeout action, periodic action, etc. both in movement and interaction behaviors. For analysis and verification of spatial and temporal properties of the systems in specification, t-CARDMI presents Timed Action Graph (TAG), where the spatial and temporal properties are visually represented in a two-dimensional diagram with the pictorial distribution of movements and interactions. t-CARDMI can be considered to be one of the most innovative formal methods in distributed real-time systems in ubiquitous computing to specify, analyze and verify the spatial, behavioral and the temporal properties of the systems very efficiently and effectively. The paper presents the formal syntax and semantics of t-CARDMI with a tool, called SAVE, for a ubiquitous healthcare application.

• Journal of the Korean Statistical Society
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• v.25 no.1
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• pp.111-122
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• 1996

A model for a system whose state changes continuously with time is introduced. It is assumed that the system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. A repairman arrives according to a Poisson process and repairs the system according to an (s,S) policy, i.e., he increases the state of the system up to S if and only if the state is below s. A partial differential equation is derived for the distribution function of X(t), the state of the system at time t, and the Laplace-Stieltjes transform of the distribution function is obtained by solving the partial differential equation. For the stationary case the explicit expression is deduced for the distribution function of the stationary state of the system.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.4
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• pp.536-544
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• 2016

The study on the precipitation particle distribution models in Korea for the environmental test and evaluation (T&E) from huge amount of measuring and reanalysis data is presented. Instead of related specifications of MIL-HDBK-310, with these models it can be possible to realize more realistic and efficient design and environmental T&E for the military and civil products especially for the atmospheric flying vehicles using in Korea.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.209-213
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• 2003

We have several kinds of DRM(Digital Rights Management) solutions which protect and control a content based on the cryptography. The current technology of DRM focuses on the content management in the purchaser. It doesn't consider the content management in the other principles like creator, provider, and distributor and doesn't provide the efficient environments of a content distribution. In this paper, we propose a digital content distribution system which processes a content and metadata with electronic copyright management.

• Bulletin of the Korean Mathematical Society
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• v.54 no.4
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• pp.1141-1158
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• 2017

In this paper, we study the value distribution of the derivative of a Dirichlet L-function $L^{\prime}(s,{\chi})$ at the a-points ${\rho}_{a,{\chi}}={\beta}_{a,{\chi}}+i{\gamma}_{a,{\chi}}$ of $L^{\prime}(s,{\chi})$. We give an asymptotic formula for the sum $${\sum_{{\rho}_{a,{\chi}};0<{\gamma}_{a,{\chi}}{\leq}T}\;L^{\prime}({\rho}_{a,{\chi}},{\chi})X^{{\rho}_{a,{\chi}}}\;as\;T{\rightarrow}{\infty}$$, where X is a fixed positive number and ${\chi}$ is a primitive character mod q. This work continues the investigations of Fujii [4-6], $Garunk{\check{s}}tis$ & Steuding [8] and the authors [12].

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1320-1322
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• 1997

The distribution of coercivity in the thickness direction were investigated by using Kerr hysteresis loop tracer for the Co-Cr films deposited by Facing Targets Sputtering apparatus. It $H_{c{\bot}}(S)- H_{c{\bot}}(I)$ correlated strongly with ${\Delta}H_c$, which represents the degree of distribution of coercivity. Furthermore, the Cr content was varied in order to improve the coercivity of intial growth layer $H_{c{\bot}}(I)$ took a maximum value of 750 Oe and the distribution of coercivity became sharper at the Cr content of 25 at.%.

• Journal of the Korean Operations Research and Management Science Society
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• v.20 no.3
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• pp.105-122
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• 1995

Based on linear models, the inference about the true measurement x$_{f}$ and the optimal designs x (nx1) for the calibration experiments are considered via Baysian statistical decision analysis. The posterior distribution of x$_{f}$ given the observation y$_{f}$ (qxl) and the calibration experiment is obtained with normal priors for x$_{f}$ and for themodel parameters (.alpha., .betha.). This posterior distribution is not in the form of any known distributions, which leads to the use of a numerical integration or an approximation for the calculation of the overall expected loss. The general structure of the expected loss function is characterized in the form of a conjecture. A near-optimal design is obtained through the approximation nof the conditional covariance matrix of the joint distribution of (x$_{f}$ , y$_{f}$ $^{T}$ )$^{T}$ . Numerical results for the univariate case are given to demonstrate the conjecture and to evaluate the approximation.n.

• Communications for Statistical Applications and Methods
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• v.29 no.3
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• pp.373-391
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• 2022

The distribution of observations in most econometric studies with spatial heterogeneity is skewed. Usually, a single transformation of the data is used to approximate normality and to model the transformed data with a normal assumption. This assumption is however not always appropriate due to the fact that panel data often exhibit non-normal characteristics. In this work, the normality assumption is relaxed in spatial mixed models, allowing for spatial heterogeneity. An inference procedure based on Bayesian mixed modeling is carried out with a multivariate skew-elliptical distribution, which includes the skew-t, skew-normal, student-t, and normal distributions as special cases. The methodology is illustrated through a simulation study and according to the empirical literature, we fit our models to non-life insurance consumption observed between 1998 and 2002 across a spatial panel of 103 Italian provinces in order to determine its determinants. Analyzing the posterior distribution of some parameters and comparing various model comparison criteria indicate the proposed model to be superior to conventional ones.

• Ocean and Polar Research
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• v.24 no.4
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• pp.457-464
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• 2002

Distribution and stock assessment of mega-benthos living in the shallow hard bottom around Dokdo were studied in July,2000. Depth and topographical conditions have affected to the densities and biomass of benthic animals. In shallow area, less than 10 m depth, turbo shell Batillus cornutus, mussel, Mytilus corusucs were dominated and showed distinct patterns in vertical distribution. On the other hand, the area over 10m depth, it showed diverse pattern depending on topography. Turbo shell, mussel and sea cucumber Stichopus japonicus were dominated in terms of fishery resources, but abalones were rarely sampled. Stock assessment were estimated to be 6.54 M/T, 3.89 M/T and 8.92 M/T, respectively. Some parts of coastal hard bottom around Dokdo, such as the area between Dongdo and Seodo, seemed to play an Important role as nursery ground. Therefore, it is necessary to the environmental monitoring for coastal fishery managements aspects.

• Journal of East-West Nursing Research
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• v.17 no.2
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• pp.164-170
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• 2011

Purpose: The aim of this study was to examine the factors that affect nurses' communication. Methods: This study employed a descriptive survey design. The sample of this study consisted of 174 nurses at hospital in Korea from June 1st to 18th, 2009. The data were analyzed SPSS/WIN 17.0 program and factors affecting nurses' communication were analyzed by multiple regression. Results: 1) Level of nurses' communication was average of 3.44, ego strength 0.36, self-image 3.53, ego distribution 2.92, interpersonal relations 3.52, and family function 3.39. 2) Nurses' communication had significant positive correlation with interpersonal relations, self-image, family function, and ego strength. On the other hand, it had not significant correlation with ego distribution. 3) Interpersonal relations (t=9.68, p<.001), ego strength (t=3.11, p=.002), and family function (t=2.26, p=.025) significantly predicted the level of nurses' communication (Adjusted $R^2$=.418, p<.001). Conclusion: The study finding suggested to develop hospitals' management program for increasing nurses' communication.