• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.3
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• pp.652-663
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• 1996

In this paper, we analyze the blocking probability of a call in a PC communication network. In a PC communication network, a call generated from the PSTN (public switched telephone network) requests the connection to the ICPS(information communication processing system) which interconnects the the PSTN and the PSDN(packet switched data network). Then, as a second step, a packet call is requested to the specific service database attached in the PSDN. The call blocking probabilies are analyzed for these two interface points, the PSTN interface ports of the ICPS and the PSDN interface link of the database. We also present some numerical results to show the effects of the system parameters on the performance of the network. The results show the effects of the capacity of each interface point on the performance point.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.9-16
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• 2010

A major purpose of management or occupational safety is a significant decrease in safety accidents. With this view, the establishment of occupational safety culture and the building of occupational communication network stand out as being more important than the past. This study has analysed the positive effects of occupational safety communication on safety consciousness and action of the employees in workplace. And it is confirmed that the occupational safety communication in workplace is the essential mechanism, through which the workers internalize safety consciousness and act safely. The safety consciousness and action of the employees are formed in safety culture, which is not only legal regulations, but a daily communication network in workplace. In these sense, the building of the occupational safety communication network is decisive for the establishment of safety culture. For these reasons, this study makes the proposition that a firm promotion of occupational communication network is necessary, which connects the safety culture and a effective safety management in workplace.

• The Journal of Information Systems
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• v.24 no.1
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• pp.67-94
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• 2015

Recently, the popularity of Social Network Service (SNS) along with the spread of smart phone, personal computer and tablet PC helps personal network to construct new forms of services in cyberspace. As such, SNS plays a significant role in constructing diverse online networks and there is a growing interest on SNS at societal level. In this vein, the purpose of the research was to find the factors affecting the continuance intention to use social network services. The major findings are summarized as follows. First, "System Quality", "Contents Quality", "Personal Innovativeness", "Self-Efficiency", "Honor Benefit" has significant effects on "Relationship Quality". Yet, "Economic Benefit" is not statistically significant on "Relationship Quality". Second, "Relationship Quality" has a significant effect on "Continuous Usage Intention". Last, our research discovered the relationship between exogenous variables which would serve as valuable inputs in the development of strategic guideline and plan for SNS companies and related services.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1996.11a
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• pp.21-28
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• 1996

The Purpose of this study was to identify the effects of the elderly Koreans of residential relocation and to find their conditioning variables that mediate some of the negative effects of residential relocation. The research was performed by questionnares. Subject samples consisted of 448 elderly individuals who have lived for two years or less in one of the two new residential communities in commuting proximity with Seoul: Ilsan or Bundang. Two variables measured for the life of the elderly to residential relocation were the change of the social relationship network and the change of the depression level. Results indicated that the relocation had a substantial disrupting effect on the social network of the elderly. The level of depression of the subjects after relocation was decresed. It was also found that the effects of the elderly to residential relocation was mainly affected by physical factors of environment and residential satisfaction.

• Journal of Distribution Science
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• v.15 no.6
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• pp.13-24
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• 2017

Purpose - The current study aims to examine the effect of social network factors on travel agency employees' occupational outcomes such as job performance and job satisfaction through innovation behavior in a comprehensive model. Research design, data, and methodology - Based on a theory of social network, the concept of social network was assessed by three factors: a) network size, b) network range, and c) tie strength. To test the proposed hypotheses, structural equation modeling (SEM) was employed based on data from 197 travel agency employees in Korea. Result - The results showed that the associational activity of network size had a positive effect on innovation behavior, while the network range of network size had a significant negative effect on innovation behavior. Subsequently, innovation behavior positively influenced on job performance and job satisfaction, respectively. Conclusions - The results offer some insights into the extended model and have important managerial implications for Korean travel agencies. More specifically, considering diverse domains of social network and organizational research, this study advances critical utility of social network factors in a high facilitating level of innovation behavior, which can help travel agency employees promote their job performance and job satisfaction.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5998-6008
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• 2015

The value of social network and entrepreneurial orientation has widely been acknowledged as a critical resource of business success. However, the previous studies did not specify each role and conceptually have examined them as separate antecedents of firm performance. This study develops propositions concerning network capabilities and investigates the moderating effects of network structures (degree centrality, closeness centrality, and betweenness centrality) on the relationship between entrepreneurial orientation and firm performance. This research conducted with a sample of 115 small consulting companies in Korea. The findings indicate that closeness centrality moderates the relationship between proactiveness and performance. Also, the combination of betweenness centrality and proactiveness exerts a positive impact on performance. Accordingly, degree centrality enhances the influence of innovativeness on performance. In particular, betweenness centrality exacerbates the influence of risk-taking on performance against our expectation. Overall, these findings conclude the synergistic effects of network capability and entrepreneurial orientation on firm performance. Finally, practical implications and academic propositions are presented regarding the way firms could most effectively utilize entrepreneurial orientation and network capability to maximize firm performance.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4405-4418
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• 2015

Different network provides different service. To maximize the profit, heterogeneous networks form a whole, which may either compete or cooperate with each other. In this paper, the healthcare monitor network architecture is introduced to build the competitive and cooperative mechanisms of heterogeneous networks which contain three networks, namely, cellular network, WLAN and WMAN. This paper considers the natural growth rate of the network with competitive and cooperative effects. Then, the stability of the proposed model and its equilibrium points are analyzed by the ordinary differential principle. Finally, simulation results show that the natural growth rate cannot increase the profit of the network, but effective cooperative among heterogeneous networks can increase the profit of each network, and competitive may decrease the profit of each network.

• Journal of information and communication convergence engineering
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• v.11 no.2
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• pp.69-81
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• 2013

Maintaining connectivity is essential in multi-hop wireless networks since the network topology cannot be pre-determined due to mobility and environmental effects. To maintain the connectivity, a critical point in the network topology should be identified where the critical point is the link or node that partitions the network when it fails. In this paper, we propose a new critical point identification algorithm and also present numerical results that compare the critical points of the network and H-hop sub-network illustrating how effectively sub-network information can detect the network-wide critical points. Then, we propose two localized topological control resilient schemes that can be applied to both global and local H-hop sub-network critical points to improve the network connectivity and the network resilience. Numerical studies to evaluate the proposed schemes under node and link failure network conditions show that our proposed resilient schemes increase the probability of the network being connected in variety of link and node failure conditions.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.79-89
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• 2011

Though many studies regarding roundabout have been recently conducted, most of them have focused on operational aspect. Moreover, majority of the previous researches analyzes operational effects of single roundabout, but seldom investigate the effects of multi-roundabouts constructed on road networks. In this study, we seek ways to construct multiple roundabouts on road network maximizing their operational effects. The analysis investigate influence of both adjacent signalized and unsignalized intersections as well as influence of the distance from those intersections to roundabouts. The results show that the optimal distance between two adjacent intersections were calculated to be 150m, and any two intersections located within 150m apart influence each other thus imposing operational restrictions on each other. In addition, those results are confirmed using simulation analysis conducted on the real urban network in Nonheon regional area, Incheon City.

• Wind and Structures
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• v.11 no.1
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• pp.35-50
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• 2008

Wind and temperature have been shown to be the critical sources causing changes in the modal properties of large-scale bridges. While the individual effects of wind and temperature on modal variability have been widely studied, the investigation about the effects of multiple environmental factors on structural modal properties was scarcely reported. This paper addresses the modeling of the simultaneous effects of wind and temperature on the modal frequencies of an instrumented cable-stayed bridge. Making use of the long-term monitoring data from anemometers, temperature sensors and accelerometers, a neural network model is formulated to correlate the modal frequency of each vibration mode with wind speed and temperature simultaneously. Research efforts have been made on enhancing the prediction capability of the neural network model through optimal selection of the number of hidden nodes and an analysis of relative strength of effect (RSE) for input reconstruction. The generalization performance of the formulated model is verified with a set of new testing data that have not been used in formulating the model. It is shown that using the significant components of wind speeds and temperatures rather than the whole measurement components as input to neural network can enhance the prediction capability. For the fundamental mode of the bridge investigated, wind and temperature together apply an overall negative action on the modal frequency, and the change in wind condition contributes less to the modal variability than the change in temperature.