• Information Systems Review
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• v.24 no.1
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• pp.59-87
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• 2022

Since over-the-top (OTT) service has emerged as a new way of consuming video contents, OTT markets grow exponentially and the competition among the OTT services becomes intense. Only limited systematic research effort has been paid to understand why users subscribe such OTT services among other services. Therefore, we used developmental sequential mixed methods approach to find out the quality factors and their effect on post-subscription experiences and continuance intention. In the qualitative study, we derived six factors which a user considers important to continue the subscription. Based on the explored factors, we hypothesized a research model with modified three qualities from ISSM. The proposed research model was validated through quantitative research, a survey of 226 OTT service users in South Korea, using structural equation modeling. The results indicated that content quality is the key factor affecting both perceived enjoyment and satisfaction whereas system quality affects satisfaction, and service quality only affects enjoyment. Enjoyment affects satisfaction which sequentially affects continuance usage intention. This study contributes to research by modifying ISSM through mixed methods. It also provides OTT service providers with insight to enhance users' post experience and continuance intention to use the service through qualities derived from the interview.

• Journal of Information Technology Services
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• v.12 no.4
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• pp.219-234
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• 2013

We introduced a framework of information systems audit methodology and applied to IS projects based on RFID/USN in six public organizations in South Korea. An analysis of five IS implementation projects shows the iterative technical specific risks are disclosed. The key 14 risk factors categorized into 4 classifications (Project Management, application, database, system architecture) which are based on the established IT audit framework in order to extend to the technology (RFID/USN) specific framework and apply to the other case as well. The implications of these findings for audit research and practice are discussed.

• Management & Information Systems Review
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• v.17
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• pp.381-399
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• 2005

During the past decade a great deal of attention has focused on the impact of IT investment. However, many related studies have frequently generated controversial or inconsistent results. These results imply that the relationship between IT investment and performance is complex and multifaceted. And empirical studies with new analytical techniques are badly needed to examine the way IT investment interacts with various organizational and environmental elements to influence corporate performance. Accordingly a study of IT investment needs to make a contingency approach to determining the level of IT investment based on the competitive strategy in a macro perspective. The basic purpose of this research is to analyse the relationship between IT investment and IT effectiveness and to identify the moderating effect of competitive strategy in the relationship. The results showed that there is no relationship between IT investment and IT effectiveness, and the competitive strategy can be considered as a significant moderating variable between IT investment and IT effectiveness.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.518-532
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• 2017

Due to the rapid growth of the amount of data, research on bigdata processing has been highlighted. For bigdata processing, CUBRID Shard is able to support query processing in parallel way by dividing the database into a number of CUBRID servers. However, CUBRID Shard can answer a user's query only when the query is required to gain accesses to a single CUBRID server, instead of multiple ones. To solve the problem, in this paper we propose a CUBRID based distributed parallel query processing system that can answer a user's query in parallel and distributed manner. Finally, through the performance evaluation, we show that our proposed system provides 2-3 times better performance on query processing time than the existing CUBRID Shard.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.04a
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• pp.225-229
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• 2007

We propose some properties of fuzzy p-value and fuzzy significance level to the fuzzy hypotheses testing for vague response data with reflected correlation in survey research, Appling the principle of agreement index, we suggest the methods for fuzzy hypothesis testing by fuzzy rejection region.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.170-174
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• 2003

In this research, we consider an integrated manufacturing/distribution planning problem in supply chain (SC) which has non-integer time lags. We focus on a capacitated manufacturing planning and capacity allocation problem for the system. We develop a mixed binary integer linear programming (MBLP) model and propose an efficient heuristic procedure using an adaptive genetic algorithm, which is composed of a regeneration procedure for evaluating infeasible chromosomes and the reduced costs from the LP-relaxation of the original model. The proposed an adaptive genetic algorithm was tested in terms of the solution accuracy and algorithm speed during numerical experiments. We found that our algorithm can generate the optimal solution within a reasonable computational time.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.388-391
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• 2003

We've been following research on the obstacle avoidance that is based on fuzzy control. We previously proposed a new method of automatically generating membership functions, which play an important role in improving accuracy of fuzzy control, by using genetic programming (GP). In this paper, we made two improvements to our proposed method, for the purpose of achieving better intelligence in fuzzy robots. First, the mutation rate is made to change dynamically, according to the coupled chaotic system. Secondly, the population partitioning using deme is introduced by parallel processing. The effectiveness of these improvements is demonstrated through several computer simulations.

• Journal of the Korean Data and Information Science Society
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• v.21 no.1
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• pp.185-194
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• 2010

In recommender systems which are used widely at e-commerce, collaborative filtering needs the information of user-ratings and neighbor user-ratings. These are an important value for recommendation in recommender systems. We investigate the in-formation of rating in NBCFA (neighbor Based Collaborative Filtering Algorithm), we suggest new algorithm that improve prediction accuracy of recommender system. After we analyze relations between two variable and Error Value (EV), we suggest new algorithm and apply it to fitted line. This fitted line uses Least Squares Method (LSM) in Exploratory Data Analysis (EDA). To compute the prediction value of new algorithm, the fitted line is applied to experimental data with fitted function. In order to confirm prediction accuracy of new algorithm, we applied new algorithm to increased sparsity data and total data. As a result of study, the prediction accuracy of recommender system in the new algorithm was more improved than current algorithm.

• Asia pacific journal of information systems
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• v.25 no.4
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• pp.719-745
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• 2015

Social networking services provide individuals with an easy approach for exchanging messages with others based on interpersonal relationships. However, why individuals spread marketer-generated content (MGC) in their online social circles remains unclear. Therefore, we develop a theoretical model to examine how social capital, intrinsic motivations, personal perceptions, past behavior, and personal traits influence MGC sharing behavior of social media users in micro-blogging context. Data collected from 319 social networking users support the proposed model. The results from partial least squares analyses show that enjoyment, perceived control, and outcome expectations are significant indicators of individual's MGC sharing intention in the social broadcasting environment. Results also suggest that social capital, users' intention, and past behavior positively influence the MGC sharing behavior of users. Moreover, individual prevention pride exhibits a significant interaction effect on the relationships between users' MGC sharing and its antecedents. Implications for research and practice are discussed.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.3
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• pp.95-106
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• 2002

As the information technology including Internet not only opened the cyber world but also has evolved as a platform that enables a new generation of businesses and remolds the shape of thinking and the rules of supply chain management (SCM). By using the Theory of Constraints, which seems simple but robust to review the traditional SCM context, the paper proposes a conceptual framework to handle the SCM issues. From the strategic perspective, this paper focuses on three policy constraints: supplier-manufacturer oriented constraints, manufacturer-distributor oriented constraints, and supply chain oriented constraints. To optimize the throughput and sustain the competitiveness of supply chain members in the dynamic business environment, the companies should utilize the potential competency of information technology and consistently perform the activities of removing and/or reinforcing the constraints.