• Proceedings of the Korean System Dynamics Society
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• 2002.02a
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• pp.19-40
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• 2002

The intent of this study is to develop system dynamics model for assessment of organizational and human factors in nuclear power plant which can contribute to secure the nuclear safety. Previous studies are classified into two major approaches. One is engineering approach such as ergonomics and probability safety assessment(PSA). The other is social science approach such like sociology, organization theory and psychology. Both have contributed to find organization and human factors and to present guideline to lessen human error in NPP. But, since these methodologies assume that relationship among factors is independent they don't explain the interactions among factors or variables in NPP. To overcome these limits, we have developed system dynamics model which can show cause and effect among factors and quantify organizational and human factors. The model we developed is composed of 16 functions of job process in nuclear power, and shows interactions among various factors which affects employees' productivity and job quality. Handling variables such like degree of leadership, adjustment of number of employee, and workload in each department, users can simulate various situations in nuclear power plant in the organization side. Through simulation, user can get insight to improve safety in plants and to find managerial tools in the organization and human side. Analyzing pattern of variables, users can get knowledge of their organization structure, and understand stands of other departments or employees. Ultimately they can build learning organization to secure optimal safety in nuclear power plant.

• International Journal of Contents
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• v.18 no.1
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• pp.1-16
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• 2022

With the advent of the 5G, networks and information and communication technologies have been continuously developed. In the fields of art galleries, virtual reality (VR) exhibitions that can be visited online have emerged, innovating the way of human-computer interaction and creating new artistic experiences for users. This study explores the three-dimensionality, clarity, and innovative interactions that users experience when viewing a VR exhibit, which affects the exhibit's presence. Besides, in terms of research method, the research sets spatial participation and immersion as dependent variables, with three-dimensionality (high versus low), clarity (high versus low), and innovation (high versus low) in a 2×2×2 design as the base, and explores their interaction effects. The results show that three-dimensionality and innovative interactions affect spatial participation. First of all, in groups with high innovation and low three-dimensionality, spatial participation presents a higher positive factor. Secondly, with regard to immersion, three-dimensionality, clarity and innovation present a tripartite interaction. Groups with low three-dimensionality and high clarity have a higher positive effect on immersion when the level of innovation is low. When the degree of innovation is high, the positive effect on immersion is higher in groups with high three-dimensionality and low clarity. The above results show that in the production of VR exhibitions, it is necessary to increase the three-dimensionality and clarity of exhibited image contents, while taking into account the user's perception and innovativeness. On the other hand, this study puts forward suggestions for the design, content and future development of VR exhibitions, which has important reference significance for the improvement and innovation of future VR exhibitions.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.97-109
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• 2014

Social media is a general term for online services by which users share opinions, perspectives, and experiences. It supports interactions between users in sharing contents on it and weak ties among them play an important role in the process. This exploratory study attempts to identify crucial factors of establishing weak ties between social media users in the perspective of social network theory and uncertainty reduction theory. We collected data through diary study and in-depth interview and analyzed it following grounded theory approach. As a result, social media users more actively interacted each other or shared contents based on weak ties, compared to strong ties. In addition, similarity, self-disclosure, and relevance appeared to facilitate establishment of weak ties, by reducing psychological distance between social media users and perceived uncertainty of them.

• The Journal of the Korea Contents Association
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• v.18 no.5
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• pp.280-291
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• 2018

Recently, various interactions have been actively conducted through sharing and expressing opinions among users in social networks. In this process, since malicious users and fault information spread misinformation, trust is reduced irrespective of their will. To solve this problem, studies have been conducted to determine the trust of a user through direct-connected users. In this paper, we propose a enhanced user indirect trust discrimination scheme considering the connection relation and influence of users. The proposed indirect trust computation scheme derives the user's area of interest through user interaction and reconstructs the existing network considering the user connection relationship. The final indirect trust is also detected by determining whether the user is a malicious user through the influence of the user. Through various performance evaluations, we show that the proposed scheme achieves better performance than the existing method.

• Journal of Information Technology Services
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• v.15 no.1
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• pp.211-226
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• 2016

Most of the SNS users argue that they feel techno-stress or digital fatigue when they use SNS. As the relationships in the SNS expand, users may feel work overload, digital fatigue, and techno-stress which are caused by the time and effort for the retaining the existing relationships established via SNS. The SNS activities require users' time and effort to update their profiles and the current news of them, responding to online friends' contents. Thus, more relationships they have, more stress they can feel. This study tries to examine the key factors that can affect subjective well-being of individuals in Social Network Service (SNS) usage. Therefore, this study, based on the previous literature, investigates what the sources of SNS stress are and how SNS stress and flow affect subjective well-being of SNS users. Major findings of this study from an empirical analysis with 201 SNS user respondents who have accessed SNS at least one time within one month are as follows. First, perceived opportunity cost and reputation recognition in SNS usage were found to have significant effects on negative emotion. Second, individual's flow in SNS was significantly affected by challenges and interactions, and had a significant impact on positive emotion. However, SNS users' flow did not show a positive relationship with their satisfaction of life. This study contributes to the expansion of theoretical discussion about the effect of individual's SNS usage on quality of life in validating whether SNS usage can bring individuals subjective well-being. Implications of the study findings and future research directions are also discussed.

• Journal of the Korea Society of Computer and Information
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• v.10 no.4 s.36
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• pp.259-274
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• 2005

In this paper, we propose a methodology to estimate the number of users in e-Commerce systems. There have been a lot of previous work under the closed-LAN system environment. But the study on the number of acceptable users in real network environment is hard to find in the literature. Our research applies a Hybrid Simulation by using QoS results for end-to-end high-speed Internet service, and experiments are performed with regard to LAN and WAN, network equipments, and various network bandwidth. As result of the experiments we observed that the response time of high-speed Internet service media(Wireless LAN, ADSL, Cable, VDSL) depends heavily on the sequence and depth of transactions and on the ratio of transactional and non-transactional interactions. That is, as the network and application get more loads, the number of acceptable users decreases. By adding a cache server and an L4 switch to the simulation model, we analysed the changes in the number of users and client response time.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.493-498
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• 2008

We proposed "Table Mediator" which is a tabletop system for digital storytelling that uses web-retrieved information for the students' educational field trip. Students can perform their storytelling for their virtual pre-field trip to build up a sequential path as a story with web-retrieved documents, satellite images, geographical information, and group discussion. The proposed system was designed to lessen the limitation of individual interaction such as restricted viewpoint and biased inclination by group digital storytelling. Local interactions also have the limitation such as insufficient information and knowledge and the system supplied the rich live information such as subjective critiques or recently discovered history, or new updates for building a story that makes users arrange their own idea as a consistent story to lessen the limitation of the local interactions. The system can be used for various applications such as travel, education and other collaborative works with group interaction.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.487-492
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• 2009

There will be many large displays in common public places, and we expect that these displays will give users many convenient interactive services. However, due to the physical size, typical mouse and keyboard are not suitable for user interactions on large displays. Recently there are many studies investigating on new interaction techniques and input devices developed for user interactions in a large display. In this paper, we describe the iTILE framework designed to help develop the interactive tiled display applications. Then we describe two iTILE applications using the tape switch interface and the tangible interface with infrared camera and markers.

• Journal of the Korean Society for information Management
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• v.23 no.2
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• pp.113-127
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• 2006

This paper addresses issues related to the design of an interface supporting fine grained interaction with documents, focusing on a particular type of scholarly documents, journal articles. In order to make a usable interface we need to understand user behaviors as well as technologies that present new possibilities of enhancing user experience. This paper reviews studies along three dimensions : user information behavior in searching/using documents, new conceptual/technical models for electronic documents, and interaction mechanisms. Putting together the understanding of users and enabling technologies, requirements and considerations in developing systems with granular interactions are discussed in the conclusion.

• International Journal of Human Ecology
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• v.16 no.2
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• pp.11-20
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• 2015

The purpose of this study was to examine the effects of the construal level and temporal distance of a message and consumer's Social Network Service (SNS) self-efficacy on consumers' attitudes toward SNS fashion advertising. This study employed a 2 (message configuration: high construal level/low construal level) ${\times}$ 2 (temporal distance: distant future/near future) ${\times}$ 2 (SNS self-efficacy: high/low) between-subject factorial design. The survey was conducted on Facebook users in their twenties (N=216). The results are as follows: First, attitude toward SNS fashion advertising and purchase intention was higher when the message construal level was lower and when the temporal distance was closer. Second, no interactions between temporal distance and message construal level for attitude toward SNS advertising and purchase intention were found in this study. However, interactions between temporal distance and SNS self-efficacy for attitude toward SNS advertising and purchase intention were found. When the SNS self-efficacy was high, message with the low construal level reacted significantly positive in terms of attitude toward the ad as well as purchase intention. It is expected that this study will provide insight for apparel makers or retailers to use SNS as a new advertising media for fashion marketing. Practical implications and limitations are discussed.