• The International Journal of Costume Culture
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• 제12권2호
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• pp.141-152
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• 2009

In this study, the business structure and characteristics of buying offices used by buyers for apparel productions through global sourcing were analyzed in specifics. Data were acquired through in-depth interviews of twelve merchandisers at representative apparel buying offices. The results of this study can be summarized as following. The business structure of a buying office varied depending on the functions, the item characteristics of products to be manufactured or the characteristics of the major buyers who were the customers. Overall, teams were formed by brands or organizations were formed by functions. Functional teams were divided within each brand team when business teams were divided by brands and personnel was divided by brands occasionally within each functional team when business teams were divided by functions. Business teams were composed of MR which managed the overall business about orders such as factory sourcing, price decision and production management and teams with various specialized skills. The teams with specialized skills were composed of Technical team, Fabric Development team, Colorist team, Quality Assurance (QA) or Quality Control (QC) team, Logistics team, Factory Audit team, and etc. For the future directions on the improvements, ways to increase international competitiveness of buying offices need to be researched and many expressed the opinion that it would be effective to move the offices to countries close to buyers or manufacturing locations as most buyers demand lower prices and shorter lead time than before and it is increasing trend for buyers and factories to do business directly without buying offices in the middle.

• 한국시뮬레이션학회논문지
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• 제12권2호
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• pp.1-11
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• 2003

In this paper, we focus an optimal policy focus optimal class of (s, S) inventory control systems. To this end, we use the perturbation analysis and apply a stochastic optimization algorithm to minimize the average cost over a period. We obtain the gradients of objective function with respect to ordering amount S and reorder point s via a combined perturbation method. This method uses the infinitesimal perturbation analysis and the smoothed perturbation analysis alternatively according to occurrences of ordering event changes. Our simulation results indicate that the optimal estimates of s and S obtained from a stochastic optimization algorithm are quite accurate. We consider that this may be due to the estimated gradients of little noise from the regenerative system simulation, and their effect on search procedure when we apply the stochastic optimization algorithm. The directions for future study stemming from this research pertain to extension to the more general inventory system with regard to demand distribution, backlogging policy, lead time, and review period. Another directions involves the efficiency of stochastic optimization algorithm related to searching procedure for an improving point of (s, S).

• 한국항만경제학회지
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• 제21권1호
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• pp.1-21
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• 2005

It has been more recent trends in container trade to make bogger ship from shipowners that many more parties concerned are getting involved. Well, it is natural to swift these situations if we have looked into container trade market in present time, which a lot of trade volumes has increased in world economy. Thus, supply side of shipping service needs to employ more capacity in the shipping market, then newbuilding may be compulsory options, that is deployment of larger ships. To cope with market situations as able shipowner, some alternatives can be also adopted, such as newbuilding, chartering and securing the space by strategic alliance. But whatever he does, shipowner has to keep in mind to prepare for the future. This is much more important factor considered to make investment decision in case of newbuilding and then he can make more efficient decision as well. However, there has been a little problems arisen due to larger ship employed on the trade route, which is linked with seaport, shipping companies and freight rates as well. Although shipowner decides to build new larger vessel as one of corporate strategic decision, there are many questions to be considered in advance. Therefore, in order to take more efficient decision, shipowner has to take into an account various situations surrounded, and then it can lead truly thoughtful decision making process.

• 항공우주산업기술동향
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• 제9권1호
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• pp.15-26
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• 2011

금융위기에 따른 경기침체로 위축되었던 항공운항시장은 빠르게 회복되고 있으며, 국제유가 급등에 따른 영향으로 구형항공기의 퇴역 및 신형항공기로의 교체가 활발히 이루어지고 있다. 2010년의 항공기 순 주문대수는 2009년과 비교하여 감소하였으나 수주잔량은 역대 최고수준을 기록하고 있어, 민간항공기 시장의 호황은 앞으로도 한동안 이어질 것으로 예상되고 있다. 이러한 시장 성장은 100~200인승 급의 단일 통로기가 선도하고 있으며, Airbus, Boeing의 기존 제작업체의 신규 항공기 개발과 Bombardier 및 중국, 러시아 등의 신규 업체에서도 시장에 새로이 진입하기 위해 노력하고 있다. 이러한 신형기체 수요의 증가와 기존 기체의 퇴역은 기존 기체에 대한 MRO 및 임대 시장을 위축을 가져오고 있으며, 국제 유가 불안과 경쟁심화에 따른 고효율 신형항공기에 대한 선호는 더욱 강조되고 있는 상황이다. 향후 20여 년간의 시장 전망을 살펴보면, 신흥시장의 성장과 기존 시장의 회복에 따라 견고한 성장세를 이어갈 것으로 예상된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2783-2804
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• 2021

In the network function virtualization environment, dynamic changes in network traffic will lead to the dynamic changes of service function chain resource demand, which entails timely dynamic adjustment of service function chain resource configuration. At present, most researches solve this problem through virtual network function migration and link rerouting, and there exist some problems such as long service interruption time, excessive network operation cost and high penalty. This paper proposes a dynamic adjustment method of service function chain resource configuration for the dynamic changes of network traffic. First, a dynamic adjustment request of service function chain is generated according to the prediction of network traffic. Second, a dynamic adjustment strategy of service function chain resource configuration is determined according to substrate network resources. Finally, the resource configuration of a service function chain is pre-adjusted according to the dynamic adjustment strategy. Virtual network functions combination and virtual machine reusing are fully considered in this process. The experimental results show that this method can reduce the influence of service function chain resource configuration dynamic adjustment on quality of service, reduce network operation cost and improve the revenue of service providers.

• Industrial Engineering and Management Systems
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• 제3권1호
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• pp.38-51
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• 2004

Over the years, most or many companies have focused their attention to the effectiveness and efficiency of their business units. As a new way of doing business, these companies have begun to realize the strategic importance of planning, controlling, and designing their own supply chain system. This paper analyzes the coordination issues in supply chains that consist of one manufacturer and multiple retailers operating under uncertain end customer demand and delivery lead-time. We use the Genetic Algorithm (GA) to determine the appropriate ordering and inventory level at which the manufacturer and multiple retailers can maximize the profit of the chain. This is performed under three controlling policies: the traditionally centralized controlling policy under the manufacturer's perspective, the entire chain’s perspective, and lastly the coordinating controlling policy with an incentive scheme. The outcome from the study reveals that the coordinating controlling policy with an incentive scheme can outperform the traditional centralized controlling policies by creating a win-win situation in which all members of the chain benefit from higher profit, thus resulting in more willingness from all members to join the chain.

• 대한임베디드공학회논문지
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• 제18권6호
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• pp.277-283
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• 2023

Vital signals provide essential information regarding the health status of individuals, thereby contributing to health management and medical research. Present monitoring methods, such as ECGs (Electrocardiograms) and smartwatches, demand proximity and fixed postures, which limit their applicability. To address this, Non-contact vital signal measurement methods, such as CW (Continuous-Wave) radar, have emerged as a solution. However, unwanted signal components and a stepwise processing approach lead to errors and limitations in heart rate detection. To overcome these issues, this study introduces an integrated neural network approach that combines noise removal, demodulation, and dominant-frequency detection into a unified process. The neural network employed for signal processing in this research adopts a MLP (Multi-Layer Perceptron) architecture, which analyzes the in-phase and quadrature signals collected within a specified time window, using two distinct input layers. The training of the neural network utilizes CW radar signals and reference heart rates obtained from the ECG. In the experimental evaluation, networks trained on different datasets were compared, and their performance was assessed based on loss and frequency accuracy. The proposed methodology exhibits substantial potential for achieving precise vital signals through non-contact measurements, effectively mitigating the limitations of existing methodologies.

• 한국전기전자재료학회논문지
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• 제37권2호
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• pp.119-132
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• 2024

Dielectric ceramic capacitors present high output power density due to the fast energy charge and discharge nature of dielectric polarization. By forming dense ceramic films with nano-grains through the Aerosol Deposition (AD) process, dielectric ceramic capacitors can have high dielectric breakdown strength, high energy storage density, and leading to high power density. Dielectric capacitors fabricated by AD process are expected to meet the increasing demand in applications that require not only high energy density but also high power output in a short time. This article reviews the recent progress on the dielectric ceramic capacitors with improved energy storage properties through AD process, including energy storage capacitors based on both leadbased and lead-free dielectric ceramics.

• 유통과학연구
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• 제22권9호
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• pp.85-95
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• 2024

Purpose: Online food delivery platforms face challenges to operational efficiency due to increasing demand, a shortage of drivers, and the constraint of a one-order-at-a-time delivery policy. It is imperative to find solutions to address the inefficiencies in the food delivery industry. Bundling multiple orders can help resolve these issues, but it requires complex computations due to the exponential increase in possible order combinations. Research design, data and methodology: This study proposes three bundle delivery systems-static, dynamic, and hybrid-utilizing a machine learning-based classification model to reduce the number of order combinations for efficient bundle computation. The proposed systems are analyzed through simulations using market data from South Korea's online food delivery platforms. Results: Our findings indicate that implementing bundle systems extends service coverage to more customers, increases average driver earnings, and maintains lead times comparable to standalone deliveries. Additionally, the platform experiences higher service completion rates and increased profitability. Conclusions: This suggests that bundle systems are cost-effective and beneficial for all stakeholders in online food delivery platforms, effectively addressing the inefficiencies in the industry.

• 한국언론정보학보
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• 제34권
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• pp.306-340
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• 2006

휴대전화의 확산은 '이동 중 연결성'과 '상호작용성'을 증대시킴으로써 공간을 새롭게 구성하고 활성화할 것으로 주장되고 있다. 또 다른 한편에서는 공적 공간을 사사화함으로써 공간 규범을 파괴하는 것으로 이야기되어지고 있다. 이에 본 연구에서는 휴대전화의 이용으로 공간의 인식과 행태, 그리고 공적 공간의 역할에서 어떠한 변화가 나타나는지를 살펴보고자 하였다. 이론적 검토와 실증적 조사 분석의 연구 결과, 첫 번째로 살펴본 시공간의 미시적 조정과 다의적 장소성을 통하여 휴대전화의 이용이 고정된 장소의 논리를 벗어나 조정과 활용이 가능한 공간이라는 인식을 변화시키는 것으로 나타났다. 두 번째로 살펴본 모바일 친구와의 항시적 연결성을 통하여 휴대전화의 이용이 공간적 공존과 분위상의 공유로 공간에서의 사회적 행태를 변화시키는 것으로 관찰되었다. 세 번째로 살펴본 공적 공간의 의미와 역할 변화를 통하여 휴대전화의 이용행태는 공간적 특성에 지배적이며, 공간의 의미와 인식 변화에 따른 공간적 규범이 정착될 것으로 분석되었다.