• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.7
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• pp.22-30
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• 2015

For long-term evolution (LTE) MIMO transmission, codebooks are used to utilize the estimated channel information under the limited feedeback environment, and related study has been actively performed. Existing codebooks include codevectos constructed based on vector quantization (VQ) and discrete Fourier transform (DFT), and the LTE standard specifies codebooks modified from these examples to support up to 8 transmit antennas. As the number of antennas increases and as the spatial channel model is used as a standard environment to evaluate the LTE transmission performance, new beamforming methods as well as codebook designs are needed. In this paper, we implement the 3-dimensional spatial channel model (3D-SCM) to analyze the key statistical characteristics of the generated channel, and present efficient ways of determining corresponding codebooks. In particular, we propose a nonuniform-phase DFT-based codebook to improve the existing uniform-phase DFT-based codebook, and evaluate its performance under the given SCM transmission environment. There exists a strong tendancy in statistical distributions of the phase difference between adjacent antenna elements for the SCM, which can be appropriately exploited in codebook design to produce a performance gain over the existing design.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.4
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• pp.15-25
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• 2016

SCM activities in a company are considered as total innovation through synchronizing supply and demand while maintaining appropriate inventory level and reducing the business operating costs. Until now, even several researches are carried out on the SCM performance of the companies which have introduced and been operating SCM, the research on the cost analysis for the inventory which occurs frequently on supply chain is still insufficient. Especially, for the electronics industry in which the product depreciation is sharp caused by the short product life cycle and the complexity of distribution channels, even the inventory related costs are a major factor in business management, since the current estimated criteria of inventory costs are limited to the interest and maintenance management costs, the criteria do not reflect the total influence of the product depreciation and lost opportunity cost which are related to the business management. Furthermore, even though the rapid price drops of the distributor inventory caused by the frequent new model launch can be covered by the product manufacturers, the scale of total costs related to the inventory has not been conceived because the price compensation is traditionally considered as a market costs. In this research, we analyzed the inventory characteristics of electronics industry in which the price depreciation happens frequently, newly defining the estimated criteria of the product total inventory cost which includes price depreciation from the product manufacturers' view. Finally we focus on the case study of a representative electronics company and verify the scale of the influence on management performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4282-4290
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• 2010

Recently, business environment is spreading from singular business to supply-chain problem. SCM(Supply Chain Management) is changing from closed and static to opened and dynamic environment, so these environment changes of SCM require to enterprise different approach than past. As supply chain is becoming opened and dynamic, a claim is being naming that converse of real-time the get reaction from to recognizing the level of supply chain problem, grope of alternative plan to solving this problem and choosing optimum alternative plan raise the enterprise competitive. But until present, the research to deal with these changes of SCM is on insufficient situation. Thus in this paper proposes the agent system by a way of realizing dynamic supply chain. The agent is going to accomplish the management activities in real-time depends on environment and given condition and designed for solving problems development and maintenance. Also, algorithms performance of the agent is tested on TAC SCM environment. Agents in TAC SCM are simulations of small manufacturers, who must compete with each other for both supplies and customers, and manage inventories and production facilities.

• Journal of Information Technology Services
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• v.15 no.1
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• pp.227-243
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• 2016

In order to maximize profitability by optimizing the entire supply chain process, enterprises have made efforts to apply IT technologies such as POS, MES, and TMS. In addition, academic societies have also made efforts to verify the effects of IT technology introduction through various researches. However, until now, there is almost no research that analyzes the relationship between the IoT, a new IT technology, and the SCM. To study the effect of IoT technology on SCM, this study conducted professional Delphi surveys for three times. Through this method, this study analyzed changes that will be caused by the IoT technology, the priority area in IoT introduction, and the expected difficulty in IoT introduction on SCM. As a result of the Delphi surveys and analyses, it was expected that when IoT technology is introduced, the level of SCM's IT use and partnership will increase. However, the effect of the increased performance of the supply chain, which includes inventory management and quality control, will become weaker. The reason is that the development of operation and management skills, as well as the improvement of IT technology, are also important elements for the performance improvement of the supply chain. As for the priority area in IoT introduction, it was expected that the effect will be greater when IoT is introduced in customer service, transportation, and delivery areas. As difficulties in IoT technology introduction, such as the shortage of IoT platform development personnel, standardization, integration with the existing system, securing professional manpower, expenses, data management, and operation, were derived, it has thus become necessary for us to exert greater efforts in order to come up with solutions.

• The Research Journal of the Costume Culture
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• v.16 no.1
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• pp.181-203
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• 2008

This study suggests a model to identify relationships between Supply Chain Partnership(SCP) and the performance of Supply Chain Management(SCM) based on apparel companies and outsourcing suppliers of finished products that are in a position of getting into Supply Chain Level on apparel industry. This research model is based on an integrated model including a relationship between relationship formation factors and partnership strengthening factors in SCP; and supply chain performance a result of that relationship. The formation factors of SCP affect emotional elements(trust, commitment) of strengthening factors, and they, in turn, impact the performance of a supply chain through behavioral elements(collaboration, information sharing)16 hypotheses were formulated to research the degree of impact of SCP on supply chain performance. Theoretical and empirical research was executed in parallel to achieve the objectives of this study. Empirical research involved a research methodology using surveys. Survey target audiences were limited to designers and merchandisers over five years of experience with apparel companies and outsourcing suppliers for finished products operating mainly in Korea. SPSS 12.0 for Windows and AMOS 5.0 were used for data and statistical analysis. Reviewing the result of research model and identification of each hypothesis, total 11 from 16 hypotheses set by this research were selected, 5 hypotheses were dropped, and 4 meaningful paths were added.

• Journal of Fashion Business
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• v.11 no.4
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• pp.221-231
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• 2007

SCM system is required inter-industrial cooperation as well as inter-organizational cooperation. It means not only standardization of inter-organization but also standardization of inter-industry. SCM makes possible one circulation from fiber to retail industry in the respects of information and product flows. QR is the SCM of textile apparel industry, which satisfy customer need with least cost and maximum profit. Customer-oriented supply chain system focused on information sharing, cost reduction, inventory control, lead time reduction, quick response on customer demand. How we can measure the performance of successful SCM is issued on the approach of Balanced Scorecard which evaluates 4 perspectives such as customer perspective, internal business perspective, financial perspective, and innovation and learning perspective. This can project the blueprint of textile fashion business to right direction with vision.

• Journal of the Optical Society of Korea
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• v.14 no.4
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• pp.351-356
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• 2010

We investigated the combined effect of fiber chromatic dispersion and self-phase modulation (SPM) in multi-channel subcarrier multiplexed (SCM) optical transmission systems. We theoretically analyzed the transmission characteristics of the SCM signals with the effect of SPM and chromatic dispersion in a single-mode optical fiber by numerical simulations based on the nonlinear Schrodinger equation. The numerical simulation results revealed that the effect of fiber dispersion and SPM could occur independently between subcarrier channels in two-channel SCM systems for small optical modulation index (OMI) and large channel spacing. However, for large OMI, small channel spacing, and large fiber launching power, we found a performance degradation of the two-channel system compared to that of a single-channel system. These parameters are therefore important for the optimization of multi-channel SCM systems applicable to radio over fiber networks.

• IE interfaces
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• v.18 no.3
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• pp.343-349
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• 2005

This study presents the empirical results of comparing several demand forecasting methods for Supply Chain Management(SCM). Adaptive exponential smoothing using change detection statistics (Jun) is compared with Trigg and Leach's adaptive methods and SAS time series forecasting systems using weekly SCM demand data. The results show that Jun's method is superior to others in terms of one-step-ahead forecast error and eight-step-ahead forecast error. Based on the results, we conclude that the forecasting performance of SCM solution can be improved by the proposed adaptive forecasting method.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.77-78
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• 2013

최근 비휘발성, 바이트 단위 접근이 가능한 스토리지 클래스 메모리 관련 시스템 소프트웨어 연구가 활발히 이루어지고 있다. 이에 본 논문에서는 SCM의 성능 및 용량, 가격 측면을 고려하여, NAND 스토리지 시스템 성능 향상을 위한 변화량 기반 저널링 기법을 제안한다. 본 기법은 기존 데이터 대비 바뀐 부분이 임계치보다 작을 경우, 해당 부분을 기록하는 저널 영역으로써 SCM을 활용한다. 분석 결과에서 알 수 있듯이 본 논문에서 제안한 기법은 NAND 페이지 쓰기 횟수를 크게 감소시킴으로써, I/O 성능 및 NAND 스토리지 수명 향상을 가져온다.

• Journal of the Korean Society of Clothing and Textiles
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• v.29 no.2
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• pp.307-317
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• 2005

The purpose of this study are to examine the supply chain management (SCM) actiities of apparel manufacturers and then to investigate the relation between apparel manufacturers' SCM activities and their major textile suppliers' and retaileers' characteristics. The data was collected from the apparel manufacturers categorized into the six product areas - woman's formal dress(30%), boy and girl's casual wear (30%), man's formal dress(15%), sports and golf wear(10%), inner wear (10%) and infant & children's wear(5%) - headquartered in Seoul, by quota convenience sampling during August 14-September 4 in 2003. From 150 questionnires of delivery, 125 were collected and 123 from 64 manufacturers were used for analysis. The SPSSWIN 10.0 was used for frequency analysis, descriptive statistics analysis, factor analysis, reliability analysis and canonical correlation analysis. the results of the study are as follows : (1) The SCM activities of apparel manufacturers showed that the activity levels of the factors of information systems ans understanding of demand characteristics were ranked on top while the activity level of collaborative partnership factor was lowest. (2) As the level of SCM activities such as communication and exchange of opinion, and commitment and leadership of a top management became higher, the elements of delivery performance, interest in total cost and relationship of the textile suppliers were more improved. (3) The SCM activities such as communication an exchange of opinion, intgrated management organization, management flexibilty, and collaorative partnership contributed for improvement of collaborative relationship with retailers.