• Journal of Aerospace System Engineering
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• v.8 no.3
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• pp.34-40
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• 2014

Since the global economic crisis in year 2008, the world civil helicopter market has been growing recently. According to the market outlook in the next decade, the demand of civil helicopter will be driven by the demand of Private & Corporate, Oil & Gas, Off-shore and EMS(Emergency Medical Service) usages. On the other side, the demand of military market will be driven by the modification and upgrading for life extension or performance enhancement than the new helicopter development for replacing old models. To summarize these situations, the demand of MRO(Maintenance, Repair & Overhaul) market has also been on the rise because of the demand due to above several usages in civil side and the life-extension in military side. Through the MRO market analysis for characteristics, developmental trends and a supply chain, this paper describes that the potential of MRO business is considerably large as a propulsive power of domestic helicopter industry. And also, it proposes the construction direction of MRO network because the domestic industry must make the developmental awareness and reliability a stepping-stone towards own helicopter.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.375-388
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• 2004

As today's business environment has become more and more competitive, forward as well as backward flows of products among members belonging to a supply chain have been increased. The backward flows of products, which are common in most industries, result from increasing amount of products that are returned, recalled, or need to be repaired. Effective management for these backward flows of products has become an important issue for businesses because of opportunities for simultaneously enhancing profitability and customer satisfaction from returned products. Since third party logistics service providers (3PLs) are playing an important role in reverse logistics operations, the 3PLs should perform two simultaneous logistics operations for a number of different clients who want to improve their logistics operations for both forward and reverse flows. In this case, distribution networks have been independently designed with respect to either forward or backward flows so far. This paper proposes a mixed integer programming model for the design of network integrating both forward and reverse logistics. Since this network design problem belongs to a class of NP-hard problems, we present an efficient heuristic based on Lagrangean relaxation and apply it to numerical examples to test the validity of proposed heuristic.

• Journal of the Korea Safety Management & Science
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• v.12 no.2
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• pp.161-166
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• 2010

EPC Information Services (EPCIS) is an EPCglobal standard designed to enable EPC-related data sharing within and across supply chain. The EPCIS standard defines standard interfaces to enable EPC-related data to be captured and subsequently to be queried using a set of service operations and an associated data model. There are two kinds of EPCIS data: event data and master data. Event data is created in the process of carrying out business processes. Traceability of goods across supply chain is based on event data. Therefore, each company must have an event data. This study compared he difference between MS-SQL(DRDBMS) and ALTIBASE(MMDBMS) for data storage. We compared the difference between two database management in many respects such as insert time and select time. We come to a conclusion that ALTIBASE is more efficient than MS-SQL.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.1-10
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• 2012

Supplier selection is an essential task within the purchasing function of supply chain management because it provides companies with opportunities to reduce various costs and realize stable and reliable production. However, many companies find it difficult to determine which suppliers should be targeted as each of them has varying strengths and weaknesses in performance which require careful screening by the purchaser. Moreover, information required to assess suppliers is not known precisely and typically fuzzy in nature. In this paper, therefore, fuzzy multi-objective linear programming (fuzzy MOLP) is presented under fuzzy goals: cost minimization, service level maximization and purchasing risk. To solve the problem, we introduce an enhanced two-phase approach of fuzzy linear programming for the supplier selection. In formulated problem, Analytical Hierarchy Process (AHP) is used to determine the weights of criteria, and Taguchi Loss Function is employed to quantify purchasing risk. Finally, we provide a set of alternative solution which enables decision maker (DM) to select the best compromise solution based on his/her preference. Numerical experiment is provided to demonstrate our approach.

• The Journal of Information Technology
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• v.2 no.1
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• pp.65-78
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• 1999

Nowadays, SCM(supply chain management) is recognized as a efficient way to overcome the limits of asset and capability of one fun through the synergy effects comes from strategic alliance. Traditionally material management and logistics are recognized as a simple functional activity. But as the importance and needs of customer service are increased, gradually these activities are given to strategic role of cutting off the cost and increasing the sales. But unlike traditional alliance, for example technology alliance or holding facility in common, SCM has many difficulties in action because of differences in organization structure and management system between two firms. So in this paper, I will review literatures about the concept and constructing factor of SCM, the conditions for effective doing and strategic implications.

• International Journal of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.218-223
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• 2021

The five elements of big data are said to be Volume, Variety, Velocity, Veracity, and Value. Among them, data lacking the Veracity of the data or fake data not only makes an error in decision making, but also hinders the creation of value. This study analyzed YouTube's revenue structure to focus the effect of data integrity on data valuation among these five factors. YouTube is one of the OTT service platforms, and due to COVID-19 in 2020, YouTube creators have emerged as a new profession. Among the revenue-generating models provided by YouTube, the process of generating advertising revenue based on click-based playback was analyzed. And, analyzed the process of subtracting the profits generated from invalid activities that not the clicks due to viewers' pure interests, then paying the final revenue. The invalid activity in YouTube's revenue structure is Raw Data, not pure viewing activity of viewers, and it was confirmed a direct impact on revenue generation. Through the analysis of this process, the new Data Value Chain was proposed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.13 no.2
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• pp.31-40
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• 2003

The current security issue for the Internet is focused on the security for user data. On the other hand, the research on the security for routing protocols is not so active, considering the importance of its role for the harmonious and accurate operation of the Internet. In this paper, we investigate the security problems of the link-state routing protocol which has been employed in the Internet, and suggest a new authentication mechanism for routing messages which complements and extends the previous ones. For this purpose, a concept of dual hash chains is newly introduced, which is provably secure, and we explain how to provide both the integrity and source authentication service for routing messages based on the session hash chains.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.27 no.3
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• pp.89-98
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• 2021

Purpose: The purpose of this study was to determine the effects of electromyography (EMG)-biofeedback based closed kinetic chain exercise (CKCE) on quadriceps muscle activity and dynamic balance ability in patellofemoral pain syndrome (PFPS). Methods: Thirty subjects with PFPS were included and they were divided into EMG-biofeedback using CKCE (Group I) and squat exercise using CKCE (Group II), each group consisted of 15 patients. Group I and Group II was performed by the patients for three times a week, for six weeks. sEMG was used to measure quadriceps muscle activity and star excursion balance test (SEBT) was used to measure dynamic balance ability. Results: According to the results of the comparisons between the groups, after intervention, quadriceps muscle activity and dynamic balance ability were significantly higher in Group I than in the Group II. Conclusion: Findings of this study suggest that EMG-biofeedback using CKCE that provides real-time biofeedback information on muscle contraction may have a beneficial effect on selective muscle strength of vastus medialis oblique muscle and dynamic balance ability in PFPS.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.759-764
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• 2021

Because sensitive and private information should be exchanged between electric vehicles and a V2G service provider, reliable communication channel is essential to operate Vehicle-to-Grid (V2G) system which considers battery of electric vehicles as a factor of smart grid. The block chain is a platform for cryptocurrency transaction and fully distributed database system running by only equivalent node in the network without help of any central management or 3^rd party. In this paper, the structure and operation method of the blockchain are investigated, and the application of the blockchain for the V2G system was also explained and analyzed.

• Journal of the Korean Society of Clothing and Textiles
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• v.47 no.4
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• pp.729-742
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• 2023

This two-part study explores the changes in the types of perceived value and consumption channels for vintage clothing and the relationship between the two variables. In Study 1, we used text mining with the keyword "fashion+vintage." Emotional value was the most frequently mentioned, and environmental value increased the most. We also revealed an increasing trend in online channels for vintage clothing consumption. In Study 2, we analyzed 30 interviews with consumers who had purchased vintage clothing through online channels. We identified 7 attributes and 20 goals for vintage consumption online and pinpointed three strong connections. First, consumers reported high levels of service satisfaction due to the usefulness of algorithms. Second, the authenticity and heritage information available through online and mobile channels were associated with consumers' perceptions of value related to financial benefits. Third, consumers sought to find rare products through online channels, leading to a strong influence on their sense of achievement. Overall, this study proposed ways to increase the value of vintage clothing perceived by consumers through consumption online.