• Journal of KIISE:Software and Applications
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• v.30 no.7_8
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• pp.672-680
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• 2003

A shopbot is a software agent whose goal is to maximize buyer´s satisfaction through automatically gathering the price and quality information of goods as well as the services from on-line sellers. In the response to shopbots´ activities, sellers on the Internet need the agents called pricebots that can help them maximize their own profits. In this paper we adopts Q-learning, one of the model-free reinforcement learning methods as a price-setting algorithm of pricebots. A Q-learned agent increases profitability and eliminates the cyclic price wars when compared with the agents using the myoptimal (myopically optimal) pricing strategy Q-teaming needs to select a sequence of state-action fairs for the convergence of Q-teaming. When the uniform random method in selecting state-action pairs is used, the number of accesses to the Q-tables to obtain the optimal Q-values is quite large. Therefore, it is not appropriate for universal on-line learning in a real world environment. This phenomenon occurs because the uniform random selection reflects the uncertainty of exploitation for the optimal policy. In this paper, we propose a Mixed Nonstationary Policy (MNP), which consists of both the auxiliary Markov process and the original Markov process. MNP tries to keep balance of exploration and exploitation in reinforcement learning. Our experiment results show that the Q-learning agent using MNP converges to the optimal Q-values about 2.6 time faster than the uniform random selection on the average.

• Journal of Navigation and Port Research
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• v.44 no.1
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• pp.44-52
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• 2020

More accurate forecasting of port cargo in the global long-term recession is critical for the implementation of port policy. In this study, the Busan Port container volume (export cargo and transshipment cargo) was estimated using the Vector Autoregressive (VAR) model and the vector error correction (VEC) model considering the causal relationship between the economic scale (GDP) of Korea, China, and the U.S. as well as ARIMA, a single volume model. The measurement data was the monthly volume of container shipments at the Busan port J anuary 2014-August 2019. According to the analysis, the time series of import and export volume was estimated by VAR because it was relatively stable, and transshipment cargo was non-stationary, but it has cointegration relationship (long-term equilibrium) with economic scale, interest rate, and economic fluctuation, so estimated by the VEC model. The estimation results show that ARIMA is superior in the stationary time-series data (local cargo) and transshipment cargo with a trend are more predictable in estimating by the multivariate model, the VEC model. Import-export cargo, in particular, is closely related to the size of our country's economy, and transshipment cargo is closely related to the size of the Chinese and American economies. It also suggests a strategy to increase transshipment cargo as the size of China's economy appears to be closer than that of the U.S.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.6
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• pp.456-464
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• 2007

This paper proposes a novel three-phase current-fed active clamp DC-DC converter for fuel cells. A single common active clamp branch is used to limit transient voltage across the three-phase full bridge and to realize zero-voltage switching(ZVS) in all switches. To apply for the power generation system current-fed type has been combined with the three-phase power conversion system. The proposed approach has the following advantages: an increase (by a factor of three) of input current and output voltage chopping frequencies; lower RMS current through the inverter switches with higher power transfer capability; reduction in size of reactive later components and the power conditioning system; better transformer utilization; increase of the system reliability. Therefore, the proposed three-phase current-fed active clamp DC-DC converter is appropriate for the boost type DC-DC converter for fuel cells and also applicable for the photovoltaic and battery charge system. The paper details the analysis, simulation and hardware implementation of the proposed system. Finally, experimental results with the proposed PWM strategy demonstrate the feasibility of the proposed scheme on a 500W prototype converter.

• Korean Security Journal
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• no.12
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• pp.117-147
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• 2006

This study aims to propose efficient way to operate the security guarding system from the perspective of administration, policy, law, institution and operation as to the private security guarding system as the Korean security guarding system needs multifaced analysis and measure to ensure efficient operation. The growth strategy has to be restructured and segmentation market needs to be driven in order to cope with the changing conditions of company from the perspective of administration. And private security guarding service companies must refrain from excessive competition while improving the contracting method such as minimum price bidding, etc. From the perspective of policy, the functions of relevant organizations such as the National Police Agency, security association, etc, and mutual cooperation must expand. Also, the profit generation event needs to be privatized and the more positive perception toward the private security guarding service is necessary. In addition, security exhibition and seminar can be expanded to lay the groundwork for the advancement of private security system. From the legal and institutional perspective, the security guarding service related law must be revised and the certification system must b introduced to cope with the changing requirement. The security guarding instructor system must be strengthened to ensure a faithful and earnest implementation of duty to instruct, supervise and educate security guarding personnel. From the perspective of security guarding system's operation, professional security technique must be introduced and applied, and the volunteer application system must be established. In addition, standard 'security guarding manual' must be crafted, and the equipment for security guarding must be modernized to ensure an efficient operation of private security guarding services.

• Journal of Service Research and Studies
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• v.3 no.2
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• pp.75-89
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• 2013

In the services industry and firms, the successful new service development is very important issue today, But the innovation process for service firms is comprehensively little treated until now. This study was performed to suggest the new service development process model for the firms level in the perspective of the radical service innovation. So, in this paper the new process development model can be made by reviewing the concepts about the radical service innovation and by analyzing the some existing new service development process models. In the suggested service development process model, the three key process such as technology forecast, market analysis, and strategy development were included for front phase activity as the new service development process. Also the four key process for searching phase, and the other three key process for implementation phase were included. And for the application for the service firms' service innovation, the innovation's outcome estimation reference model is included. I hope to be executed the various case research and the improvement and optimization for this suggested process model in the future.

• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.745-754
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• 2014

Students experience a variety of achievement-related emotions during the process of learning the science curriculum. The purpose of this study is to develop an achievement emotions questionnaire for Korean middle school science curriculum to measure the achievement emotions that middle school students experience during study of this curriculum, and verified its validity. The Achievement Emotions Questionnaire-Korean Middle School Science is based on the English version of the Achievement Emotions Questionnaire, developed with reference to Korean middle school science curriculum and the characteristics of science study, from the perspective of the control-value theory of achievement. It has 232 questions, configured to measure nine achievement emotions across three types of academic settings. The questionnaire results can be treated with a high degree of confidence according to the result of our validation, which also verified that the achievement emotions of these students are configured with four internal criteria (learning strategy, achievement motivation and course grade), as suggested by the control-value theory; this in turn verifies that the nine achievement emotions are sufficiently distinctive across study situations. Last, it was verified that the questionnaire has sufficient external validity based on a comprehensive examination of the relation between science achievement emotions and the four criterion variables for each student. This suggests that through the development and implementation of this quantitative questionnaire, basic ground was provided to understand the achievement emotions experienced by middle school students learning the science curriculum.

• Asia pacific journal of information systems
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• v.3 no.2
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• pp.3-54
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• 1993

Recently, executives learned of the strategic impact that information systems (IS) and information technology (IT) could provide to their organizations. In other words, through IS/IT companies could squelch competition, secure suppliers, obtain customer loyalty, reduce the threat of new entrants, and identify new opportunities. Because of these potential benefits, organizations are investing ever-increasing amount of organizational resources in IS/IT to make their organizations as information-based ones. Information-based organizations depend largely upon computer hardwares and softwares for their ongoing operations and management. Thus, organizations must manage their information resources, especially hardwares and softwares very effectively to remain competitive. Information resource management (IRI) is a program of activities directed at making effective use of information technology within an organization. These activities cover from corporate IS/IT planning to application system development, implementation, and maintenance. In more detail, IRV activities include planning for and acquiring computer hardwares and communication equipments, planning for, selection, and management of software development projects, and re-engineering business processes as IS/IT are integrated into organizational management. Among these activities, planning for and acquisition of computer hardwares, and planning for and management of software projects are the most critical ones since these activities require enormous amount of such important corporate resources as money, people, and time. Furthermore, corporate's eventual success largely depends upon whether corporate's policy on IS/IT is effective one or not. Numerous approaches and concepts to specific IRM activities have been proposed. However, many organizations have experienced various problems in the process of applying these approaches to their IRM activities mainly because existing methodologies and guidelines are too general to adapt to each firm's unigue situation. Also, these approaches are having its own strengths and weaknesses. Thus, people in charge of organization's IRM policy should come up with effective guidelines to maintain his position very long. In this study, we reviewed some existing approaches for planning, evaluation, and acquisition of computer hardware. Then, real experiences from Taechang Steel Co., Ltd. located in Taegu, which is one of the largest Coil Service Centers in Korea, are discussed. The major purposes of the study are : (1) to discuss the tradeoffs of existing approaches on hardware evaluation and acquisition, (2) to provide a real experience of a company to facilitate the application of theoretical concepts to the real environment.

• Information Systems Review
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• v.9 no.1
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• pp.191-214
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• 2007

This study analyzes the process of establishing BSC based strategic performance evaluation system of KOMSCO. This case could be a reference to other public institutes for BSC introduction and efficient BSC usage. Internal control system of KOMSCO has been improved by EVA system in 1999, BSC introduction and Job analysis in 2001 through 2002, and BSC performance evaluation system in 2004. KOMSCO tries to reflect BSC concept by inducing employees to cooperate selection process of CSF and KPI and by considering the organizational characteristics of KOMSCO in constructing it's performance indices. It is suggested that these processes are very important and should be followed by other institutes in their BSC introduction. By applying BSC, KOMSCO provides improvement in employees' understanding of strategy, performance management, and performance evaluation. KOMSCO' information system based on ERP and efficiently connected to EIS, KMS, and BSC seems to play an important role of BSC application. BSC system of KOMSCO is now in the early stage of application and needs to be evaluated by the efficiency of usage in terms of overall performance evaluation system, deduction system of evaluation point for excess accomplishment over target, and connection to budget system.

• Journal of Science and Technology Studies
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• v.18 no.1
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• pp.177-217
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• 2018

This study examines the case of living lab applied in the R&D initiatives for solving societal problems and challenges. It discusses how to use the living lab in national R&D projects. The analyzed cases are 'Develop portable fundus camera for eye disease screening test to resolve health inequalities' and 'Auto-sensing integrated system development in rural pedestrian crosswalk'. As a result of the analysis, both cases were designed as a user participatory R&D structure by utilizing living lab. In other words, living lab has operated as a system that evolves technology-products-services into an infrastructure. It can realize final demand specification, product, service improvement and demonstration through continuous interaction of end users. As a result of the case analysis, the following policy tasks can be derived. First, living lab is a new concept and it is in the early stage of implementation in Korea. Therefore, it is necessary to monitor and evaluate living lab experiments and build suitable models for Korean society by sharing cases and achievements. Second, the strategic niche management are necessary for the introduction of living lab. Third, living lab can be used as a tool to transform the existing technology acquisition centered innovation policy to the policy for customer needs and problem solving. Fourth, there is a need for flexibility and adaptability in strategy and system to correct errors that appear in the living lab processes.

• Korean Journal of Social Welfare
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• v.57 no.3
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• pp.363-387
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• 2005

The purpose of this study is to find out implications which can be useful for enhancement of user participation in Korean disability services from UK community care experience. In Korea, until recently dominant issue on social services always has been the shortage of service provision. But during the recent 20 years, we experienced great expansion in quantity, as though it may be not yet enough. And more recently, disabled people and organizations began to actively argue for appropriate service in quantity and quality. Now, Korean disability policy and practice are confronted to the difficult and embarrassing task how to meet the need of disabled people with limited resources, and how to response to the disabled people's voice arguing on independence and choice. This task would require somewhat deliberate reform which might be quite different from previous one. UK's experience of implementation and development of community care system would give meaningful implications to Korean disability service policy and practice related to user participation. The results of the review on user participation issues in the UK community care give several implications to Korean disability services. Above all, consumerist approach which is the key strategy adopted by UK community care change is not appropriate for Korean disability service because of largely different service environment. The second implication is about decentralization. To enable decentralization of social service leads to enhancement of user involvement avoiding a lowering of service quality, prerequisite conditions should be secured. A third is securing and making declaration on the disabled person's right to assessment and constructing public service system operated by case management process. Fourth, formalized complaints procedure should be established. Fifth, professional education which enables professionals to encourage participation of disabled people should be developed, and the role of disability movement leading disabled users to participate on their services also should be highlighted.