• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4268-4290
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• 2015

Future mobile communications face enormous challenges as traditional voice services are replaced with increasing mobile multimedia and data services. To address the vast data traffic volume and the requirement of user Quality of Experience (QoE) in the next generation mobile networks, it is imperative to develop efficient content distribution technique, aiming at significantly reducing redundant data transmissions and improving content delivery performance. On the other hand, in recent years cloud computing as a promising new content-centric paradigm is exploited to fulfil the multimedia requirements by provisioning data and computing resources on demand. In this paper, we propose a cooperative caching framework which implements State based Content Distribution (SCD) algorithm for future mobile networks. In our proposed framework, cloud service providers deploy a plurality of cloudlets in the network forming a Distributed Cloud Service Network (DCSN), and pre-allocate content services in local cloudlets to avoid redundant content transmissions. We use content popularity and content state which is determined by content requests, editorial updates and new arrivals to formulate a content distribution optimization model. Data contents are deployed in local cloudlets according to the optimal solution to achieve the lowest average content delivery latency. We use simulation experiments to validate the effectiveness of our proposed framework. Numerical results show that the proposed framework can significantly improve content cache hit rate, reduce content delivery latency and outbound traffic volume in comparison with known existing caching strategies.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.103-115
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• 2008

The purpose of this paper is that investigates a model of burnout and coping strategy employees in out-bound travel agency. So, we investigated the relationship between burnout variables(emotional exhaustion, depersonalization, reduces personal accomplishment) and employee's job satisfaction, intentions to resign. And we suggest that coping strategies will control the relationship between burnout and job attitude. We used social support, self esteem, and leisure involvement as a coping method. Data obtained from survey of frontline employees working in the several outbound travel agencies in Seoul, Korea. In the result, it has strong relationships between burnout and job-relative components. Perceived burnout phenomenon has negatively effect on job satisfaction and positively effect on resign intention. Coping variables controled in the relationship between burnout and job satisfaction. In the practical implications, managers can take an action as like a social support to reduce employee's burnout. And employee has activity hobby for reducing the burnout.

• Journal of Intelligence and Information Systems
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• v.9 no.2
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• pp.121-133
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• 2003

Due to the rapid growth of Internet, means of communication with customers in a traditional customer support environment such as telephone calls are being replaced by mainly e-mail in a Web-based customer support system. Although such a Web-based support is efficient and promises potential benefits for firms, including reduced transaction costs, reduced time, and high quality of support, there are some difficulties associated with responding to many types of customer's inbound e-mails appropriately. As many types of e-mail are received, considerable attention is being paid to methods for increasing the efficiency of managing and responding e-mails. This research proposes an intelligent system for managing customer's inbound e-mails in organizations by applying case based reasoning technique for responding to various customers' inbound e-mails more effectively. In this approach, a case is represented as a frame-typed data structure corresponding to an inbound e-mail, keywords, and its reply e-mail. In the retrieval procedure, keywords and affinity set is developed to index a case, and then the case is represented as a vector, a case vector. Also, cosines value is calculated to measure the similarity between a new inbound e-mail and the cases in the case base. In the adaptation procedure, we provide several adaptation strategies to adapt and modify the retrieved case. The strategies guide to make an outbound e-mail using product databases, databases for customer support, etc. Additionally, the Web-based system architecture is proposed to implement our methodology. The proposed methodology and system will be helpful for developing more efficient Web-based customer support.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.5B
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• pp.277-285
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• 2007

In this paper, we present a simulation model of Slammer worm propagation process which caused serious disruptions on Internet in the you of 2003 and analyze the process of Slammer by using NS-2. Recently introduced NS-2 modeling called "Detailed Network-Abstract Network Model" had enabled packet level analysis. However, it had deficiency of accommodating only small sized network. By extending the NS-2 DN-AN model to AN-AN model (Abstract Network-Abstract Network model), it is effectively simulated that the whole process from the initial infection to the total network congestion on hourly basis not only for the Korean network but also for the rest of the world networks. Furthermore, the progress of the propagation from Korean network to the other country was also simulated through the AN-AN model. 8,848 hosts in Korean network were infected in 290 second and 66,152 overseas hosts were infected in 308 second. Moreover, the scanning traffics of the worm at the Korean international gateway saturated the total bandwidth in 154 seconds for the inbound traffic and in 135 seconds for the outbound one.

• Proceedings of the KAIS Fall Conference
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• 2003.11a
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• pp.185-190
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• 2003

Due to the rapid growth of Internet, means of communication with customers in a traditional customer support environment such as telephone calls are being replaced by mainly e-mail in a Web-based customer support system. Although such a Web-based support is efficient and promises potential benefits for firms, including reduced transaction costs, reduced time, and high quality of support, there are some difficulties associated with responding to many types of customer’s inbound e-mails appropriately .As many types of e-mail are received, considerable attention is being paid to methods for increasing the efficiency of managing and responding e-mails. This research proposes an intelligent system for managing customer’s inbound e-mails in organizations by applying case based reasoning technique for responding to various customers' inbound e-mails more effectively. In this approach, a case is represented as a frame-typed data structure corresponding to an inbound e-mail, keywords, and its reply e-mail. In the retrieval procedure, keywords and affinity set is developed to index a case, and then the case is represented as a vector, a case vector. Also, cosines value is calculated to measure the similarity between a new inbound e-mail and the cases in the case base. In the adaptation procedure, we provide several adaptation strategies to adapt and modify the retrieved case. The strategies guide to make an outbound e-mail using product databases, databases for customer support, etc. Additionally, the Web-based system architecture is proposed to implement our methodology. The proposed methodology and system will be helpful for developing more efficient Web-based customer support.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.9
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• pp.1399-1404
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• 2022

The transition to the untact era caused by the COVID-19 pandemic has greatly shrunk Korea's continuously growing tourism industry. In this paper, the size, gender ratio, and gender ratio of foreign tourists before and after the outbreak of Corona, gender ratio, It was noted that there was a very large change in the purpose of the visit. Considering the end of the mandatory outdoor mask, the lifting of the mandatory quarantine for all overseas arrivals regardless of vaccination, and the number of outbound tourists who started to recover rapidly from the first half of 2022, this thesis examines how the interest in Korean tourism in the post-corona era is I wanted to see if it had changed. To this end, we analyzed how major tourism-related search keywords changed before and after COVID-19, and suggested changes necessary for the development of the Korean tourism industry.

• Fashion & Textile Research Journal
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• v.17 no.4
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• pp.561-573
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• 2015

The influence of tourists on the retail market in Korea continues to grow, and China has become the largest outbound-spending nation in the world. Korea's retail industry must comprehend the sophisticated consumption behavior of Chinese tourists. Hence, we explored how the experiential value of shopping in Korea affected Chinese tourists' satisfaction levels regarding stores and products. Findings from this study suggest entertainment and escapism mediate the effect of experiential value on consumer attitudes toward products and stores. This research was conducted with Chinese female tourists who shopped in Korea during their latest visit to this country. CFA and SEM were implemented using AMOS 20.0. The analysis of survey data produced interesting results. Visual appeal, crowding, and service excellence had positive impacts on entertainment, and they had a positive influence on both store satisfaction and product satisfaction. Regarding escapism, crowding and economic benefits had positive impacts, whereas visual appeal and service excellence had no effects. Results showed that escapism had a negative influence on attitudes toward both products and stores. To be clear, escapism refers to the status of absorption by which consumers are highly occupied with pleasant feelings, therefore, shopping when the motive of escapism is high is likely to be less rational and more impulsive. In this study, the diverse roles of different emotions associated with entertainment and escapism in the context of tourism shopping were identified. The findings provide practical implications for developing retail strategies and highlight the importance of the experiential values of shopping for tourists.

• Management & Information Systems Review
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• v.33 no.1
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• pp.237-261
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• 2014

This study is to investigate the impact of information technology implementation on supply chain risk and performance. It focuses on how information technology adoption affects supply risk as well as performance. It collected one hundred fifty nine responses from supply executives and supply and purchasing managers of U.S manufacturing firms by applying a survey methodology. The research results provide empirical evidence that the use of information technology in the supply chain mitigates supply risk and improves performance. More importantly, information technology adoption involves three aspects: inbound and outbound communications, internal communications and administration and finally, mitigation of supply risks and improved performance via order taking and procurement. This research emphasizes the importance of IT implementation in supply risk management. It also points out how information technology adoption facilitates the impact of information technology in risk mitigation in the supply chain and in performance. Thus, supply and purchasing managers need to consider IT implementation and adoption when establishing their risk mitigating strategies within the supply chains.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.431-437
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• 2005

In korea, Freight generation models developed in korea were estimated by spatial unit method which predict freight flow by traffic zone. But it is difficult to predict freight generation using these models, because there are the difference of the totality method of sampling data on freight volume and the variability of the variables by these models on each case study, This study developed new estimation model to predict freight flow which is generated from each company using the characteristics of each company such as the freight outbound & inbound volume, the number of employee, sales, gross area, land area. This model is simpler than the that of spatial unit and can apply to the other region. The subjects of study were companies in metropolitan area and types of model were exponential regression models. The adequate explanatory variable in the models were sales. this study have a uniqueness apply micro research method to estimate freight generation not use spatial unit method but use flow unit method by each company unit.

• Journal of Intelligence and Information Systems
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• v.24 no.2
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• pp.243-264
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• 2018

Although the worldwide battery market is recently spurring the development of lithium secondary battery, lead acid batteries (rechargeable batteries) which have good-performance and can be reused are consumed in a wide range of industry fields. However, lead-acid batteries have a serious problem in that deterioration of a battery makes progress quickly in the presence of that degradation of only one cell among several cells which is packed in a battery begins. To overcome this problem, previous researches have attempted to identify the mechanism of deterioration of a battery in many ways. However, most of previous researches have used data obtained in a laboratory to analyze the mechanism of deterioration of a battery but not used data obtained in a real world. The usage of real data can increase the feasibility and the applicability of the findings of a research. Therefore, this study aims to develop a model which predicts the battery deterioration using data obtained in real world. To this end, we collected data which presents change of battery state by attaching sensors enabling to monitor the battery condition in real time to dozens of golf carts operated in the real golf field. As a result, total 16,883 samples were obtained. And then, we developed a model which predicts a precursor phenomenon representing deterioration of a battery by analyzing the data collected from the sensors using machine learning techniques. As initial independent variables, we used 1) inbound time of a cart, 2) outbound time of a cart, 3) duration(from outbound time to charge time), 4) charge amount, 5) used amount, 6) charge efficiency, 7) lowest temperature of battery cell 1 to 6, 8) lowest voltage of battery cell 1 to 6, 9) highest voltage of battery cell 1 to 6, 10) voltage of battery cell 1 to 6 at the beginning of operation, 11) voltage of battery cell 1 to 6 at the end of charge, 12) used amount of battery cell 1 to 6 during operation, 13) used amount of battery during operation(Max-Min), 14) duration of battery use, and 15) highest current during operation. Since the values of the independent variables, lowest temperature of battery cell 1 to 6, lowest voltage of battery cell 1 to 6, highest voltage of battery cell 1 to 6, voltage of battery cell 1 to 6 at the beginning of operation, voltage of battery cell 1 to 6 at the end of charge, and used amount of battery cell 1 to 6 during operation are similar to that of each battery cell, we conducted principal component analysis using verimax orthogonal rotation in order to mitigate the multiple collinearity problem. According to the results, we made new variables by averaging the values of independent variables clustered together, and used them as final independent variables instead of origin variables, thereby reducing the dimension. We used decision tree, logistic regression, Bayesian network as algorithms for building prediction models. And also, we built prediction models using the bagging of each of them, the boosting of each of them, and RandomForest. Experimental results show that the prediction model using the bagging of decision tree yields the best accuracy of 89.3923%. This study has some limitations in that the additional variables which affect the deterioration of battery such as weather (temperature, humidity) and driving habits, did not considered, therefore, we would like to consider the them in the future research. However, the battery deterioration prediction model proposed in the present study is expected to enable effective and efficient management of battery used in the real filed by dramatically and to reduce the cost caused by not detecting battery deterioration accordingly.