• The Journal of Asian Finance, Economics and Business
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• v.1 no.4
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• pp.15-21
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• 2014

The main purpose of the research is to suggest a new business model of direct distribution of organic agricultural products cultivated in suburban area. To secure competitiveness, logistics cost reduction is important through direct transaction of organic agricultural products cultivated on suburban area. The research addresses food safety, farmers' income and unemployment issues with Eco-M business model. The research methods include investigation on the followings: current domestic agriculture; related problems on the existing literature reviews; the current status of suburban agriculture; specialty store of eco-friendly agricultural products. Eco-M business model can solve various problems of suburban agriculture supply system, challenges of organic farming specialty stores, unemployment issues, and difficulties of processing verticalization. Future research should include followings. First, there should be comparative analysis between businesses of environment-friendly specialty stores through suburban agriculture and producer's agriculture connected with organic farming market. Second, it is required to develop strategy of environment-friendly specialty stores. Finally, analysis of the potential of Sextic industries is necessary throughout production-process-service process.

• Journal of Internet Computing and Services
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• v.20 no.3
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• pp.85-92
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• 2019

In this paper, we extract the quantitative relation data of activities from the workflow event log file recorded in the XES standard format and connect them to rediscover the workflow process model. Extract the workflow process patterns and proportions with the rediscovered model. There are four types of control-flow elements that should be used to extract workflow process patterns and portions with log files: linear (sequential) routing, disjunctive (selective) routing, conjunctive (parallel) routing, and iterative routing patterns. In this paper, we focus on four of the factors, disjunctive routing, and conjunctive path. A framework implemented by the authors' research group extracts and arranges the activity data from the log and converts the iteration of duplicate relationships into a quantitative value. Also, for accurate analysis, a parallel process is recorded in the log file based on execution time, and algorithms for finding and eliminating information distortion are designed and implemented. With these refined data, we rediscover the workflow process model following the relationship between the activities. This series of experiments are conducted using the Large Bank Transaction Process Model provided by 4TU and visualizes the experiment process and results.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.267-271
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• 2005

This paper deals with two kinds of novel shape switched reluctance motors (SRM) with magnetic barriers in order to improve operating performances of prototype. The magnetic barriers make rotor poles more saturated, and consequently inductance profiles are distorted. The changed inductance affects input current shape and eventually torque characteristics. In order to analyze the complicated flux pattern of the SRM with magnetic barriers and its terminal characteristics simultaneously, coupled field circuit modeling method is used. The finite element method is used to model the nonlinear magnetic field, and coupled to the circuit model of the SRM overall system. After experimental results are presented to prove the accuracy of the method, the several analysis results are compared, and the improved rotor shape is presented.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.3
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• pp.215-223
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• 2005

An electrical machine for a high-speed flywheel for energy storage in large hybrid electric vehicles is described. Design choices for the machine are motivated: it is a radial-flux external-rotor permanent-magnet synchronous machine without slots in the stator iron and with a shielding cylinder. An analytical model of the machine is briefly introduced whereafter optimization of the machine is discussed. Three optimization criteria were chosen: (1) torque; (2) total stator losses and (3) induced eddy current loss on the rotor. The influence of the following optimization variables on these criteria is investigated: (1) permanent-magnet array; (2) winding distribution and (3) machine geometry. The paper shows that an analytical model of the machine is very useful in optimization.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.59-75
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• 2013

As education environment is changing rapidly and competition of education industry is more intensive, the importance of service view about education is increasing as a differential competitive advantage. This study attempted to investigate the impact of service convenience as a different competitive advantage on e-learning acceptance by using TAM. The purpose of this study is to examine how five-dimensional service convenience constructs(decision convenience, access convenience, transaction convenience, benefit convenience, post-benefit convenience) affect consumers' perceived usefulness, attitude and usage intention. For this study, data were gathered from respondents who bought or used e-learning services and analyzed by structural equation model. Among the five-dimensional service convenience constructs, two constructs(benefit convenience, post-benefit convenience) affected consumers' positive perceived usefulness, attitude and usage intention about e-learning service. The results show that management and investment to improve benefit and post-benefit service convenience make consumers' positive attitude and usage intention about e-learning service.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.396-402
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• 2005

In an electricity market with imperfect competition, participants devise bidding plans and transaction strategies to maximize their own profits. The market price and the quantity are concerned with the operation reserve as well as the bidding system and demand curves in an electricity market. This paper presents a market model combined by an energy market and an operating reserve market. The competition of the generation producers in the combined market is formulated as a gaming of selecting bid parameters such as intersections and slopes in bid functions. The Nash Equilibrium (NE) is analyzed by using bi-level optimization; maximization of Social Welfare (SW) and maximization of the producers' profits.

• Journal of Technology Innovation
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• v.11 no.2
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• pp.219-238
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• 2003

This study aims to investigate the impact of wide use of digital technology, in particular, the Internet, on innovation process and corporate strategy in electronics industry. The introduction of digital technology has changed innovation process, business model and organizational structure of the electronics companies. With the wide use of digital technology, the entire value chain of electronics industry from procurement, sales, and marketing to R&D and manufacturing has been restructured. This paper examine how digital technology has changed firms' behaviors in various areas through e-commerce, virtual reality and simulation, the rise of a new type of firm called EMS (Electronics Manufacturing Services), and etc. Amidst these changes building up innovation-friendly organization has emerged as a critical concern for firms. Due to the striking decrease of transaction cost, a network type of organization has proliferated, and a business function turns into a modular organization. As a whole, digital technology has pushed electronics firms into developing their own business model, which takes consideration of standardization of business platform and their core competency.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.19 no.37
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• pp.251-261
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• 1996

Databases are critical to business information systems and RDBMS is most widely used for the database system. Normalization was designed to control various anomalies(insert, update, and delete anomalies). However normalized database design does not account for the tradeoffs necessary for the performance reason. In this research, we model a database design problem without storage constraint. Given a normalized database design, in this model, we do the denormalization of duplicating columns in order in reduce frequent join processes. In this paper, we consider insert, update, delete, and storage cost, and the anomalies are treated by additional disk I/O cost necessary for each insert, update transaction. We propose a branch and bound method, and show considerable cost reduction.

• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.3-24
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• 1996

Databases are critical to business information systems, and RDBMS is most widely used for the database system. Normalization has been designed to control various anomalies(insert, update, and delete anomalies). However, normalized database design does not account for the tradeoffs necessary for the performance. In this research, we develop a model for database design by denormalization of duplicating attributes in order to reduce frequent join processes. In this mood, we consider insert, update, delete, and query costs. The anomaly and data inconsistency are removed by additional disk I/O which is necessary for each update and insert transaction. We propose a branch and bound method for this model, and show considerable cost reduction.

• Journal of the Korean Operations Research and Management Science Society
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• v.22 no.1
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• pp.159-182
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• 1997

This study is to establish the validity of EDI adoption model Korean Companies. The research model is hypothesized in the external factors of company directly affect on EDI adoaption and the internal factors of company moderately affect on the direct effect. The external factors of company consists of economic factors, organizational power factors, and technological factor. The internal factors of company consists of the size of the company, innovative tendency of the top management, and maturity of the information technology. In the result of data analysis-the data were collected from a total of 81 companies in 6 industries adopted variables are the existence of EDI standard, transaction frequency, inter-organizational bargaining power, and pressure from industry association. Also size of the company and innovative tendency of the top management in a company's internal factors were adopted as moderate variables.