• Earthquakes and Structures
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• v.14 no.3
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• pp.203-214
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• 2018

Predictive demand and collapse fragility functions are two essential components of the probabilistic seismic demand analysis that are commonly developed based on statistics with enormous, costly and time consuming data gathering. Although this approach might be justified for research purposes, it is not appealing for practical applications because of its computational cost. Thus, in this paper, Bayesian regression-based demand and collapse models are proposed to eliminate the need of time-consuming analyses. The demand model developed in the form of linear equation predicts overall maximum inter-story drift of the lowto mid-rise regular steel moment resisting frames (SMRFs), while the collapse model mathematically expressed by lognormal cumulative distribution function provides collapse occurrence probability for a given spectral acceleration at the fundamental period of the structure. Next, as an application, the proposed demand and collapse functions are implemented in a seismic fragility analysis to develop fragility and consequently seismic demand curves of three example buildings. The accuracy provided by utilization of the proposed models, with considering computation reduction, are compared with those directly obtained from Incremental Dynamic analysis, which is a computer-intensive procedure.

• Journal of the Korean Home Economics Association
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• v.30 no.4
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• pp.153-165
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• 1992

The objectives of this study were to develop a probabilistic model for both hypotheses testing and mobility prediction. Methodologies being used for the analysis include multivariated analysis for descriptive statistics and logit model for hypotheses testing and prediction. The study used questionaire survey data conducted by Korean Research Institute for Human Settlements (KRIHS) in 1988. There were a total of 1,620 Samples, and both SPSS and Limdep software packages were used for statistical analysis and model testing. The major findings were highlighted as follows; The residential mobility over family life span by the social class were developed with the use of the probability model. Most of households in low class moved downwardly. They had lived the small-owned single detached house in first family life span and moved into the small-rented single detached house in next family life span. Most of households in middle class moved upwardly. They had lived the small-owned apartment in first family life span and moved into the large-owned single detached house in last family life span. Most of households in high class horizontally. They had lived the large-owned single detached house in first family life span and moved into the same one except in last family life span.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.3
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• pp.182-197
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• 2016

One of the distinctive characteristics of industrial engineering (IE) is its multidisciplinarity. This paper explores the multidisciplinary nature of IE using journal citation network analysis. Using the relatedness indexes of IE journals obtained from journal citation report (JCR), we firstly construct the IE network only composed of 26 IE journals. The resulting IE network is partitioned into three sub-networks: management engineering, manufacturing/quality, and ergonomics. We then propose the IE convergence network which includes 81 related journals in other disciplines as well as 26 IE journals. Scrutinizing the IE convergence network reveals that IE has a high degree of interactions with seven disciplines : Operations Research and Management Science, Statistics and Probability, Manufacturing Engineering, Computer Science, Engineering Design, Business Management, Human Factors and Ergonomics. We investigate the contributions of the related disciplines to IE as well as contributions of IE to the related disciplines. The role of IE journals in exchanging knowledge with related disciplines is also identified by brokerage analysis. It is shown that visualizing and analyzing the IE convergence network can provide an excellent overview of the multidisciplinary structure of IE, which can help IE researchers easily grasp the state-of-the art of IE research.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.623-633
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• 2012

Let {${\Omega}$, $\mathcal{F}$, P} be a probability space and {$X_n|n{\geq}1$} be a sequence of random variables defined on it. A finite sequence of random variables {$X_n|n{\geq}1$} is said to be conditionally negatively associated given $\mathcal{F}$ if for every pair of disjoint subsets A and B of {1, 2, ${\cdots}$, n}, $Cov^{\mathcal{F}}(f_1(X_i,i{\in}A),\;f_2(X_j,j{\in}B)){\leq}0$ a.s. whenever $f_1$ and $f_2$ are coordinatewise nondecreasing functions. We extend the H$\grave{a}$jek-R$\grave{e}$nyi-type inequality from negative association to conditional negative association of random variables. In addition, some corollaries are given.

• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.883-897
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• 2008

This paper provides correct informations inflecting the present situation using the sample design in population that the National Statistical Office puts in operation of the mining and manufacturing industry statistical survey in 2006. This paper proposes new sampling design which is able to grasp business fluctuations and provide basic data for the rearing policy and management of the material industry and components industry. These sample design are the modified cut-off method and multivariate Neyman allocation using principal components and sampling method is the probability proportional systematic sampling.

• International Journal of Contents
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• v.2 no.2
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• pp.17-24
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• 2006

The work presented in this paper is divided into two parts. The first part presents finite urn problems which generate truncated negative binomial random variables. Some combinatorial identities that arose from the negative binomial sampling and truncated negative binomial sampling are established. These identities are constructed and serve important roles when we deal with these distributions and their characteristics. Other important results including cumulants and moments of the distributions are given in somewhat simple forms. Second, the distributions of the maximum of two chi-square variables and the distributions of the maximum correlated F-variables are then derived within the negative binomial sampling scheme. Although multinomial theory applied to order statistics and standard transformation techniques can be used to derive these distributions, the negative binomial sampling approach provides more information and deeper insight regarding the nature of the relationship between the sampling vehicle and the probability distributions of these functions of chi-square variables. We also provide an algorithm to compute the percentage points of these distributions. We supplement our findings with exact simple computational methods where no interpolations are involved.

• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.158-168
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• 2005

In this study, the discharging effluents from have been 9 municipal wastewater treatment plants surveyed for 1 year-period. Statistics including probability distribution, cumulative occurrence concentration and other statistical parameters were presented. In addition, treatment performance and its stability were also discussed. Most of the plants, have an operational problem of high soluble organic content in the secondary effluent which may be associated with the integrated treatment of human and livestock manures. Nitrogen concentration in the effluents were usually higher during the period of summer and winter. It was found that this is mainly due to lack of the proper C/N ratio during the summer, or/and the effects of low temperature and less dilution by dry weather during the winter. Phosphorus concentration is sharply increased in June. Discussion with plant operators told that it is due to the dissolution of phosphate from the sludge accumulated in the primary settling tanks from the early spring to june. During this period, usually, sludge treatment line is highly overloaded with flush-outs of the sediments also stored in the bottom of combined sewer due to the low flow during winter season. Most of the plants can meet new effluent discharge limits of the nitrogen and phosphorus, and total coliform without further treatment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.1
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• pp.128-139
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• 2017

Vehicular Ad hoc Network (VANET) is one of technologies to realize various ITS services for safe driving and efficient traffic control. However, data delivery in VANETs is complicated due to high mobility and unreliable wireless transmission. In this paper, we develop a novel forwarding scheme to deliver packets in a reliable and timely manner. The proposed forwarding scheme uses traffic statistics to predict the encounter of two vehicles, and optimize its forwarding decision by taking into consideration the probability of successful transmission between them at the encounter place. We evaluate our scheme through simulations and show that our proposed scheme provides reliable data delivery in VANETs.

• Journal of Communications and Networks
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• v.12 no.3
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• pp.222-230
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• 2010

In this paper, we present a closed-form approximation of the average sum rate of zero-forcing (ZF) beamforming (BF) with semi-orthogonal user selection (SUS). We first derive the survival probability associated with the SUS that absolute square of the channel correlation between two users is less than the orthogonalization level threshold (OLT).With this result, each distribution for the number of surviving users at each iteration of the SUS and the number of streams for transmission is calculated. Secondly, the received signal power of ZF-BF is represented as a function of the elements of the upper triangular matrix from QR decomposition of the channel matrix. Thirdly, we approximate the received signal power of ZF-BF with the SUS as the maximum of scaled chisquare random variables where the scaling factor is approximated as a function of both OLT and the number of users in the system. Putting all the above derivations and order statistics together, the approximated ergodic sum rate of ZF-BF with the SUS is shown in a closed form. The simulation results verify that the approximation tightly matches with the sample average for any OLT and even for a small number of users.

• Journal of East-West Nursing Research
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• v.19 no.2
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• pp.104-113
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• 2013

Purpose: Due to the academic demands from a theory and practice-based educational program, nursing students often experience psychological burdens. The purpose of this study was to investigate the effect of mindfulness meditation programs on nursing students' perceived stress, depression, and self-efficacy. Methods: A quasi-experimental study with a non-equivalent control group pretest-posttest design was used. Participants were recruited from two nursing colleges. The sample consisted of an intervention group (n=29) that participated in a mindfulness meditation program and a control group (n=30). The experimental group participated in the program for 120 minutes a week for a total of 8 sessions. The data were collected prior and after the intervention using self-administered questionnaires. Data were analyzed using descriptive statistics, $X^2$-test, Fisher's exact probability test, and the t-test. Results: After the application of the mindfulness meditation program, the experimental group showed a significant difference in perceived stress(t=-10.33, p<.001), depression (t=-2.17, p=.035), and self-efficacy (t=2.57, p=.013) scores. However, there was no significant differrence in the control group. Conclusion: These findings provide a supportive evidence of mindfulness meditation program as a behavioral intervention to reduce stress, depression and increase self-efficacy among nursing students.