• Journal of Korean Institute of Industrial Engineers
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• v.32 no.2
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• pp.111-119
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• 2006

In the last decade, the research of the usability of mobile phones has been a newly evolving area with few established methodologies and realistic practices that ensure capturing usability in evaluation. Thus, there exists a growing demand to explore appropriate evaluation methodologies that evaluate the usability of mobile phones quickly as well as comprehensively. This study aims to develop a task-based usability checklist based on heuristic evaluation in views of mobile phone UI practitioners. A hierarchical structure of UI design elements and usability principles related to mobile phones were developed and then utilized to develop the checklist. In order to demonstrate the practical effectiveness of the proposed checklist, comparative experiments were conducted on the usability checklist and usability testing. A majority of usability problems found by usability testing and additional problems were discovered by the proposed checklist. It is expected that the usability checklist proposed in this study could be used quickly and efficiently by usability practitioners to evaluate the mobile phone UI in the middle of the mobile phone development process.

• Proceedings of the KSPS conference
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• 2006.11a
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• pp.109-112
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• 2006

This paper presents a dialogue interface using the dialogue management system as a method for controlling home appliances in Home Network Services. In order to realize this type of dialogue interface, we first investigated the user requirements for Home Network Services by analyzing the dialogues entered by users. Based on the analysis, we were able to extract 15 user intentions and 22 semantic components. In our study, example dialogues were collected from WOZ (Wizard-of-OZ) environment to implement a reasoning model for generating meaningful responses for example-based dialogue modeling technique. An overview of the Home Network Control System using proposed dialogue interface will be presented. Lastly, we will show that the Dialogue Management System trained with our collected dialogues behaves properly to achieve its task of controlling Home Network appliances by going through the steps of natural language understanding, response reasoning, response generation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.10 s.253
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• pp.1227-1234
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• 2006

Up to now, several mathematical theories based on strain energy functions have been developed for rubber materials. These theories, coupled with the finite element method, can be used very effectively by engineers to analyze and design rubber components. However, due to the complexities of the mathematical formulations and the lack of general guidelines available fur the analysis of rubber components, it is a formidable task for an engineer to analyze rubber components. In this paper a method for predicting strain energy functions - Neo-Hookean model and Mooney-Rivlin model - from the hardness using the empirical equation without any experiment is discussed. First based on the elasticity theories of rubber, the relation between stress and strain is defined. Then for the butyl rubbers, the model constants of Neo-Hookean model and Mooney-Rivlin model are calculated from uniaxial tension tests. From the results, the usefulness of the empirical equation to estimate elastic modulus from hardness is confirmed and, fur Mooney-Rivlin model, the predicted and the experimental model constants are compared and discussed.

• Journal of the Korean Institute of Educational Facilities
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• v.22 no.2
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• pp.15-22
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• 2015

The latest educational curriculum in Korea started in 1997, and the 'Departmentalized Classroom System', which is a distinguishing modern concept compared with conventional pedagogy, has already been used in several high schools since 2009 and will be expanded to all middle school and high schools by 2014. However, most Korean schools are not yet physically ready to implement the new system. Moreover, despite many trials during the last three years, the characteristic and architectural function of a place called 'Home-base' is still vague and has caused many controversial arguments. In fact, a large number of home-base designs failed to accomplish their original task and there are counter evidences that shows reality was quite different over architect's personal and subjective radical plan. Therefore, this study seeks to introduce and objective scientific method based on an mathematical model of an optimized algorithm for planning a home-base area in a school design. The algorithm developed in this study is designed to determine the most efficient location for a home-base area to minimize the distance students typically need to walk.

• The Journal of Korean Association of Computer Education
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• v.14 no.5
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• pp.71-79
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• 2011

We designed and implemented a cooperative learning system using social network service which can be utilized on a smart phone for users to read each other's posting once they upload posting and to give feedback concerning the posting in real time without the need for accessing a relevant website, through the installation of a necessary application which makes it possible for learners to interact at any time in any place on a smart phone. The developed program is used as an intermediate tool for real-time communications so as to aid in solving the task of learners, and it was made to boost academic achievement as well as interest in learning through real-time interactions and feedback. Furthermore, the program was designed in such a way that an instructor actually helps learners by closely identifying their levels based on accumulated data.

• Journal of Power Electronics
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• v.15 no.1
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• pp.256-267
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• 2015

Grid-connected transformerless photovoltaic (PV) inverters (TPVIs) are increasingly dominating the market due to their higher efficiency, lower cost, lighter weight, and reduced size when compared to their transformer based counterparts. However, due to the lack of galvanic isolation in the low voltage grid interconnections of these inverters, the PV systems become vulnerable to leakage currents flowing through the grounded star point of the distribution transformer, the earth, and the distributed parasitic capacitance of the PV modules. These leakage currents are prohibitive, since they constitute an issue for safety, reliability, protection coordination, electromagnetic compatibility, and module lifetime. This paper investigates a wide range of multi-kW range power rating TPVI topologies and classifies them in terms of their leakage current attributes. This systematic classification places most topologies under a small number of classes with basic leakage current attributes. Thus, understanding and evaluating these topologies becomes an easy task. In addition, based on these observations, new topologies with reduced leakage current characteristics are proposed in this paper. Furthermore, the important efficiency and cost determining characteristics of converters are studied to allow design engineers to include cost and efficiency as deciding factors in selecting a converter topology for PV applications.

• Structural Engineering and Mechanics
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• v.37 no.1
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• pp.17-37
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• 2011

This paper presents a new Internet-based computational framework for the realistic simulation of multi-scale response of structural systems. Two levels of parallel processing are involved in this frame work: multiple local distributed computing environments connected by the Internet to form a cluster-to-cluster distributed computing environment. To utilize such a computing environment for a realistic simulation, the simulation task of a structural system has been separated into a simulation of a simplified global model in association with several detailed component models using various scales. These related multi-scale simulation tasks are distributed amongst clusters and connected to form a multi-level hierarchy. The Internet is used to coordinate geographically distributed simulation tasks. This paper also presents the development of a software framework that can support the multi-level hierarchical simulation approach, in a cluster-to-cluster distributed computing environment. The architectural design of the program also allows the integration of several multi-scale models to be clients and servers under a single platform. Such integration can combine geographically distributed computing resources to produce realistic simulations of structural systems.

• International Journal of Internet, Broadcasting and Communication
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• v.11 no.2
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• pp.59-66
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• 2019

The emergence of new IT technologies and convergence industries, such as artificial intelligence, bigdata and the Internet of Things, is another chance for South Korea, which has established itself as one of the world's top IT powerhouses. On the other hand, however, privacy concerns that may arise in the process of using such technologies raise the task of harmonizing the development of new industries and the protection of personal information at the same time. In response, the government clearly presented the criteria for deidentifiable measures of personal information and the scope of use of deidentifiable information needed to ensure that bigdata can be safely utilized within the framework of the current Personal Information Protection Act. It strives to promote corporate investment and industrial development by removing them and to ensure that the protection of the people's personal information and human rights is not neglected. This study discusses the strategy of deidentifying personal information protection based on the analysis of fake news. Using the strategies derived from this study, it is assumed that deidentification information that is appropriate for deidentification measures is not personal information and can therefore be used for analysis of big data. By doing so, deidentification information can be safely utilized and managed through administrative and technical safeguards to prevent re-identification, considering the possibility of re-identification due to technology development and data growth.

• Journal of Distribution Science
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• v.19 no.7
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• pp.19-27
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• 2021

Purpose: Former research has argued that organizations in distribution channels face several issues to make a better team-based system. The purpose of the present research is to measure between employee's job performance and three major issues which disturb a solid team system. Research design, data and methodology: Scant past studies are available to guide for team practitioners which elements should be eliminated to improve team performance. To achieve this goal, the present authors obtained 267 US workers in distribution channels and conducted ANOVA test to measure the relationship between three team issues (Free-rider, Trust, and Communication) and job performance. Results: Our statistical findings clearly suggests that there was a statistically recognizable difference at the significance level of probability between the mean value of employees' job performance and three major issues, showing the high degree of job performance can be occurred by eliminating three major team issues. Conclusions: Therefore, the present research concludes that it is necessary that team-based management in the supply chain should focus on removing free-rider issues and also adopt open communication lines to overcome team-building challenges due to communication. Above all else, the ability to increase trust can be enhanced via task delegation and more team members' engagement.

• Journal of Internet Computing and Services
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• v.23 no.5
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• pp.17-23
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• 2022

Network slicing is a promising paradigm and significant evolution for adjusting the heterogeneous services based on different requirements by placing dynamic virtual network functions (VNF) forwarding graph (VNFFG) and orchestrating service function chaining (SFC) based on criticalities of Quality of Service (QoS) classes. In system architecture, software-defined networks (SDN), network functions virtualization (NFV), and edge computing are used to provide resourceful data view, configurable virtual resources, and control interfaces for developing the modified deep reinforcement learning agent (MDRL-A). In this paper, task requests, tolerable delays, and required resources are differentiated for input state observations to identify the non-critical/critical classes, since each user equipment can execute different QoS application services. We design intelligent slicing for handing the cross-domain resource with MDRL-A in solving network problems and eliminating resource usage. The agent interacts with controllers and orchestrators to manage the flow rule installation and physical resource allocation in NFV infrastructure (NFVI) with the proposed formulation of completion time and criticality criteria. Simulation is conducted in SDN/NFV environment and capturing the QoS performances between conventional and MDRL-A approaches.