• 전자공학회논문지
• /
• 제52권7호
• /
• pp.22-30
• /
• 2015

LTE (long-term evolution) MIMO 시스템에서는 제한된 피드백 환경 하에서 추정된 채널 정보를 활용하기 위한 코드북이 사용되고 있으며, 이와 관련된 연구도 활발히 진행되었다. 기존에 활용된 방식으로는 VQ (vector quantization) 기반 및 DFT(discrete fourier transform) 기반으로 생성된 코드벡터를 활용하는 코드북이 있으며, LTE 표준에서도 이를 변형한 방식을 최대 8개의 송신 안테나에 대해 적용할 수 있게 규정하고 있다. 그러나 안테나 개수가 추가적으로 증가하고, 공간 채널 모델이 LTE 시스템 전송 성능 평가에 기본적인 모델로 활용됨에 따라, 이에 따른 새로운 빔포밍 방안 및 코드북 설계가 필요하다. 본 논문에서는 LTE 전송 성능 평가에 활용되는 3차원 공간 채널 모델 (3D Spatial Channel Model; 3D-SCM)의 구현을 통해 생성된 채널의 핵심적인 통계적 특성을 분석하고, 이에 따른 코드북 설계의 방향성을 제시하고자 한다. 특히 DFT 기반 코드 북 활용 시, 기존의 균일위상 DFT 코드북을 개선한 비균일위상 DFT 코드북을 제안하고, 주어진 SCM 환경에서 성능을 평가한다. 코드벡터 설계에 필요한 인접한 안테나 원소 간의 위상차의 통계적 특성의 경우 SCM에서 뚜렷한 경향성이 존재하며, 이를 적절히 활용함으로써 기존 방식 대비 이득을 발생시킬 수 있다.

• 산업경영시스템학회지
• /
• 제39권4호
• /
• pp.15-25
• /
• 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.

• 한국산학기술학회논문지
• /
• 제11권11호
• /
• pp.4282-4290
• /
• 2010

자재구매계획, 생산계획, 그리고 고객에게 상품을 전달하기 위한 유통계획 등 공급원재료 및 자재를 공급하는 공급자로부터 고객에게 제품을 전달하기까지의 전 과정을 포함하는 공급사슬관리는 과거 폐쇄적이고 정적인 것에서 개방적이고 동적인 환경으로 변화되고 있다. 이러한 공급사슬의 환경적 변화는 기업에게 공급사슬의 운영과 관리 방식 있어 다른 접근방법을 요구하고 있다. 그러나 현재까지는 이러한 환경변화에 대응하기 위한 실험이나 연구는 부족한 상황이다. 한편 TAC-SCM (Trading Agent Competition Supply Chain Management)는 실험적인 환경을 제공하고 있다. TAC-SCM 환경은 공급자-생산자-고객의 3단계 사슬로 구성된다. 생산자는 PC 조립업체로 에이전트로 구현된다. 각 에이전트는 고객으로부터의 주문을 성사시키기 위해 서로 경쟁해야 하며, PC를 조립하기 위해 필요한 부품을 구매하기 위해서도 서로 경쟁해야 한다. 이를 위해 각 에이전트는 고객과의 협상, 생산계획, 자재구매계획, 상품인도를 위한 유통계획 등의 일반적인 공급사슬관리 업무를 자동으로 수행해야 한다. 본 연구에서는 2008년도 TAC-SCM 게임 규칙을 따른 에이전트를 구현하였으며 구현된 알고리즘과 실험결과를 소개하였다.

• 한국IT서비스학회지
• /
• 제15권1호
• /
• pp.227-243
• /
• 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.

• 한국항만경제학회지
• /
• 제40권2호
• /
• pp.191-204
• /
• 2024

본 연구에서는 항공물류산업의 소부장 전문기업을 대상으로 AHP 기반의 생산관리 직무교육을 개발하였다. AHP 모형은 1계층과 2계층으로 설계하였다. 생산관리 직무교육의 1계층의 요인으로는 구매관리역량, 자재관리역량, 공정관리역량, SCM역량이 선정되었다. 각 1계층에 2계층 평가요인을 선정하였다. AHP 분석결과, 1계층 평가요인의 상대적 중요도는 SCM 역량(0.322), 공정관리역량(0.314), 자재관리역량(0.201), 구매관리역량(0.163)의 순으로 나타났다. 1계층 중에는 SCM역량과 공정관리역량의 중요도가 높게 나타난 것으로 분석되었다. 항공물류산업의 소부장 기업의 생산관리 교육과정 개발을 위한 평가요인의 우선 순위는 다음과 같이 분석되었다. 먼저, SCM역량의 2계층인 공급망 성과관리가 최우선 요인으로 분석되었고, 공정관리 역량의 2계층인 설비보전관리, SCM 역량의 2계층인 공급망 생산운영, 공정관리 역량의 2계층인 공정픔질관리, SCM 역량의 2계층인 공급망 운송관리와 공급망 공급계획 등으로 평가요인의 우선순위가 도출되었다

• 복식문화연구
• /
• 제16권1호
• /
• pp.181-203
• /
• 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 the Optical Society of Korea
• /
• 제14권4호
• /
• pp.351-356
• /
• 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.

• 패션비즈니스
• /
• 제11권4호
• /
• pp.221-231
• /
• 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.

• 한국의류학회지
• /
• 제29권2호
• /
• pp.307-317
• /
• 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.

• 산업공학
• /
• 제18권3호
• /
• pp.343-349
• /
• 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.