• Journal of Korean Society of Transportation
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• v.10 no.3
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• pp.7-20
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• 1992

The common cycle time for the linded signals is usually determined for the critical intersecion, just because the cpacity of a signalized intersection depends on the cycle time. This may not be optimal since the interactions between the flow and the spatial structure of the route or the area are disregarded in this case. It is common to separate the total delay incurred at signals into two parts, a deterministic or uniform delay and a stochastic or random delay. The deterministic delays and the stochastic delays on the artery particularly related to signal cycle time. For this purpose a microscopic simulation technique is used to evaluate deterministic delays, and a macroscopic simulation technique based on the principles of Markov chains is used to evaluate stochastic delays with over flow queue. As a result of investigating the relations between deterministic delays and cycle time in the various circumstances of spacing of signals and traffic volume. As for stochastic delays the resalts of comparisons of the macroscopic simulation and Newell's approximation with the microscopic simulation indicate that the former is valid for the degree of saturation less than 0.95 and the latter is for that above 0.95. Newell's argument that the total stochastic delay on an arterial is dominated by that at or caused by critical intersection is certified by the simulation experiments. The comprehensive analyses of the values of optimal cycle time with various conditions lead to a model. The cycle time determined by this model shows to be approximately 70% of that calculated by Webster's.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.117-125
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• 2022

Along with the uprising of sustainability issues in the field of business and management, firms increasingly strategize and mobilize resources towards sustainability related activities and processes much more than ever. Together with this phenomenon, the concept of corporate sustainability has been noticed much more by scholars and practitioners from diverse fields. However, differently with an expectation, it is undoubted that there is a small controversy when we treat the issues related to its definition, antecedents, consequences, processes and so on. Based on this kind of understanding, this study tries to suggest and advance a new approach to the corporate sustainability based on the premises of social capital theory for social relations, which explains the role of institutions, and norms that shape firms 'social interactions. Main argument is that firm's voluntary, progressive, and proactive activities for sustainability issues can be understood as the firm's social capital building processes. Though there are a little existing study dealing with this issue, this study has a difference with them by proposing social capital building issues based on firm's real activities. Finally, case analyses based on a new approach are suggested and the theoretical considerations with some limitations are explained.

• Nuclear Engineering and Technology
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• v.29 no.6
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• pp.459-467
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• 1997

The steady-state behavior of recycling neutral atoms in a tokamak edge region has been analyzed through a two-dimensional Monte Carlo simulation. A particle tracking algorithm used in earlier research on the neutral particle transport is applied to this Monte Carlo simulation in order to perform more accurate calculations with the EDGETRAN code which was previously developed for a two-dimensional edge plasma transport in the authors' laboratory. The physical model of neutral recycling includes charge-exchange and ionization interactions between plasmas and neutral atoms. The reflection processes of incident particles on the device wall are described by empirical formulas. Calculations for density, energy, and velocity distributions of neutral deuterium-tritium atoms have been carried out for a medium-sized tokamak with a double-null configuration based on the KT-2 conceptual design. The input plasma parameters such as plasma density, ion and electron temperatures, and ion fluid velocity are provided from the EDGETRAN calculations. As a result of the present numerical analysis, it is noticed that a significant drop of the neutral atom density appears in the region of high plasma density and that the similar distribution of neutral energy to that of plasma ions is present as frequently reported in other studies. Relations between edge plasma conditions and the neutral recycling behavior are discussed from the numerical results obtained herein.

• KIEAE Journal
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• v.10 no.5
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• pp.31-41
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• 2010

The direction of Urban regeneration is changing toward holistic regeneration with residents' participation all over the world. While world leading projects in holistic regeneration such as "Ballymun of Ireland" and "Buffalo of U.S.A" appeared, recently in Korea, "Rainbow project" is getting paid attention as a similar example due to its Socio-Physical approach. The purpose of this study is to find the Effect of Socio-Physical Regeneration on Social Network characteristics of Elderly Residents in a public rental apartment. The subjects of the study are elderly residents who have resided since much before the environmental intervention. The research methods is in-depth interview. Specific features of social network included awareness of the physically improved surrounding environment, awareness of and participation in welfare programs, social interactions, identity, and vandalism behavior. As results, most of elderly residents recognized environmental improvement and felt very positive enough to enhance their attachment and pride in their residences. Physical environment changes had a considerable impact on the social network characteristics and also had a strong influence on their relations with community. Considering that permanent public rental housing has been a socially isolated place, it is significant to notice that residents' perception of being excluded and behaviors are changed gradually being influenced by environmental improvement.

• Journal of Korea Planning Association
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• v.54 no.3
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• pp.15-26
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• 2019

The development of science and transportation technology leads to the increase of inter - city networks that play an important role in urban growth. Overall, numerous studies based on network theory pay attention to positive effects of urban network on urban growth. However, some studies have pointed out the negative effects of inter-city interactions such as straw effects. This implies that the network between cities may not be positively correlated with urban growth, and that the direction of the influence may vary from a certain threshold, such as the marginal utility curve. In this context, the purpose of this study is to measure the impacts of network with central city on urban growth in the capital region and examine the relationship between urban network and growth. Two multiple regression models are employed with changes in population and employment as dependent variables. The urban network index and other control variables are used as independent variables. Especially, the urban network indexes are used in quadratic forms to examine non linear relations with urban growth such U-shape or an inverted U-shape. The results show that the relationships between networks with the central city and urban growth are not a simple linear, and the influence can be changed from the critical point.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.9
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• pp.241-248
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• 2022

The current article examines the interactions among students' attitudes to e-learning, their implementation of e-learning in their studies, and learning effectiveness. Significantly, it emphasizes the mediating role of accepting e-learning in training. It applied reliability analyses to test the measurement of items and construct validity, using the research data collected from students at Vietnam National University of Ho Chi Minh. Then, the current article used multiple regressions to inspect the causal relations; and applied procedures to investigate the mediating influence. The empirical results indicate students' attitude to e-learning positively influences their implementation of e-learning in their studies. When students apply e-learning in their studies, they likely achieve the best possible training effectiveness. Statistical evidence on the mediating role of accepting e-learning in training by students on the linkage between their attitude to e-learning and training effectiveness is revealed in this article. The findings of this article make some contributions. For educational administrators, it offers insight into the links among students' attitudes to e-learning, their implementation of e-learning in their studies, and training effectiveness, which likely allows them to establish suitable online training programs. This will be beneficial to both learners and educational institutes.

• Journal of Korean Academy of Nursing
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• v.35 no.6
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• pp.1004-1013
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• 2005

Purpose: The main purpose of this study was to explore nurse-patient interaction behaviors and patient satisfaction with the interaction in the emergency department. Method: This study used video technology to record complete conversations between the nurse and patient, thus obtaining the interactions naturally occurring in a clinical setting. The participants were 28 nurses and 63 patients in the emergency department at one university hospital located in Seoul. The data was collected from November, 2002 to April, 2003. The video recordings were observed for 4 hours for each case and coded using an adapted version of Roter's Interaction Analysis System (RIAS), which yields frequencies of thirty-six types of interaction behaviors. Result: The information exchange related to therapeutic items including medications, simple orientation, and situational positive talk were characterized in the nurses' interaction behaviors. Giving information about one's own condition, questions about therapeutic regimen, and showing worry were characterized in patient interaction behaviors. The patients' satisfaction with the interaction was 37.75.9 (range 9-45). Conclusion: The emergency nurse-patient interaction behavior was task-related. The results suggest that identification of effective interaction behavior in the Emergency department and an interaction skill training program could increase patient satisfaction.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.12C
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• pp.1200-1208
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• 2003

Affective computing plays an important role in intelligent Human Computer Interactions(HCI). To detect emotional events, it is desirable to construct a computing model for extracting emotion related features from video. In this paper, we propose a statistical model based on the probabilistic distribution of low level features in video shots. The proposed method extracts low level features from video shots and then from a GMM(Gaussian Mixture Model) for them to detect emotional shots. As low level features, we use color, camera motion and sequence of shot lengths. The features can be modeled as a GMM by using EM(Expectation Maximization) algorithm and the relations between time and emotions are estimated by MLE(Maximum Likelihood Estimation). Finally, the two statistical models are combined together using Bayesian framework to detect emotional events in video.

• Journal of The Korean Astronomical Society
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• v.46 no.1
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• pp.41-47
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• 2013

I present a simple scheme for the treatment of gravitational interactions on galactic scales. In anal- ogy with known mechanisms of quantum field theory, I assume ad hoc that gravitation is mediated by virtual exchange particles-gravitons-with very small but non-zero masses. The resulting den- sity and mass profiles are proportional to the mass of the gravitating body. The mass profile scales with the centripetal acceleration experienced by a test particle orbiting the central mass, but this comes at the cost of postulating a universal characteristic acceleration $a_0{\approx}4.3{\times}10^{-12}msec^{-2}$ (or $8{\pi}a_0{\approx}1.1{\times}10^{-10}msec^{-2}$). The scheme predicts the asymptotic flattening of galactic rotation curves, the Tully-Fisher/Faber-Jackson relations, the mass discrepancy-acceleration relation of galaxies, the surface brightness-acceleration relation of galaxies, the kinematics of galaxy clusters, and "Renzo's rule" correctly; additional (dark) mass components are not required. Given that it is based on various ad-hoc assumptions and given further limitations, the scheme I present is not yet a consistent theory of gravitation; rather, it is a "toy model" providing a convenient scaling law that simplifies the description of gravity on galactic scales.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.929-936
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• 2004

A major limitation of available component-based platforms Is that they do not provide suitable means for describing and reasoning on the concurrent behaviour of interacting component-based system. Indeed while these platforms provide convenient ways to describe the typed signatures of components, e.g. like CORBA's IDL, they offer a quite low-level support to describe the concurrent behaviour of component. The ability to describe and verify the concurrent behaviour of interacting components is key aspect In the development of large component-based software system. This study propose a component interface specification using process algebra and configuration's role which allows one to prove correctness of software architecture generated at design level as well as to define compatibility relations by our evolution rule and $\pi$-graph. Also, we shown on an appropriateness of a specification techniques and definitions proposed in this paper by case-study.