• 유통과학연구
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• 제20권12호
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• pp.89-98
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• 2022

Purpose: Due to the rapid growth of e-commerce in Thailand, the operational excellence of distribution service providers has been elevated. Thus, this research investigated the key drivers of operational performance of e-commerce distributors in Thailand. The research contains key variables: the analytics capabilities of an organization, supply chain disruption orientation, innovation capability, and operational performance. Research design, data, and methodology: An online survey is administered to top managers and key personnel (N=425) employed for at least one year in Thailand's top five e-commerce distributors. The sampling methods were conducted using purposive sampling, quota sampling, and convenience sampling. Confirmatory Factor Analysis and Structural Equation Model were applied to analyze and confirm the model's goodness-of-fit and hypothesis testing. Results: The findings reveal that an organization's analytics capabilities significantly affect supply chain disruption orientation and supply chain resilience. Furthermore, operational performance is affected by supply chain disruption, supplier quality management, and innovation capability. Nevertheless, supply chain resilience and digital supply chain have no significant effect on operational performance. Conclusions: The results imply that supply chain digitalization could drive higher operational performance. Distribution businesses are encountering transformation and disruption, which should address the high level of a digital supply chain, innovation, and quality management to maximize their profit margin and delivery service quality.

• 정보처리학회논문지D
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• 제14D권6호
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• pp.689-700
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• 2007

정보시스템 운영리스크를 최소화하고, 장애시간 동안의 영업기회 손실비용 규모를 줄이기 위해서는 장애의 예방과 사전준비가 필요하다. 그런데 장애가 발생할 경우, 대부분의 기업에서는 장애발생 직후에 대응과 복구 조치를 취하고 있다. 프로그램 개발자나 시스템운영자들은 과거의 경험과 직관에 의존하여 장애를 관리하고 있을 뿐, 장애를 체계적으로 관리하고 사전에 예방하는 사례를 찾아보기가 힘든 실정이다. 본 논문은 정보시스템 운영리스크의 관점에서, 디스크 장애예방을 위한 피해저감모델의 개발에 초점을 맞추었다. 연구모델은 디스크장치에서 정보시스템 운영리스크가 발생하는 위험원인, 그리고 이러한 원인들을 사전에 점검하는 점검주기, 점검에 필요한 운영규정으로 구성된다. 또한 정보시스템 부문의 하드웨어 장애요인 중에서 가장 크게 나타나고 있는 디스크 장애에 대하여 피해저감모델을 적용함으로써 활용 가능성을 보여 준다.

• Journal of Power Electronics
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• 제11권3호
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• pp.350-359
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• 2011

This paper describes the operational analysis results of a DC micro-grid using a detailed model of distributed generation. A detailed model of wind power generation, photo-voltaic generation and fuel cell generation was implemented with an userdefined model created with PSCAD/EMTDC software and coded in C-language. The operational analysis was carried out using PSCAD/EMTDC software, in which the power circuit is implemented by a built-in model and the controller is modeled by an user-defined model that is also coded in C-language. Various simulation results confirm that a DC micro-grid can operate without any problems in both the grid-tied mode and in the islanded mode. The operational analysis results confirm that the DC micro-grid makes it feasible to provide power to the load stably. It can also be utilized to develop an actual system design.

• Ocean and Polar Research
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• 제43권3호
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• pp.179-192
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• 2021

In this study, an integrated wave model from global to coastal scales was developed to improve the operational wave prediction performance of the Korean Meteorological Administration (KMA). In this system, the wave model was upgraded to the WaveWatch III version 6.07 with the improved parameterization of the source term. Considering the increased resolution of the wind input field and the introduction of the high-performance KMA 5^th Supercomputer, the spatial resolution of global and regional wave models has been doubled compared to the operational model. The physical processes and coefficients of the wave model were optimized for the current KMA global atmospheric forecasting system, the Korean Integrated Model (KIM), which is being operated since April 2020. Based on the sensitivity experiment results, the wind-wave growth parameter (β_max) for the global wave model was determined to be 1.33 with the lowest root mean square errors (RMSE). The value of β_max showed the lowest error when applied to regional/coastal wave models for the period of the typhoon season when strong winds occur. Applying the new system to the case of August 2020, the RMSE for the 48-hour significant wave height prediction was reduced by 13.4 to 17.7% compared to the existing KMA operating model. The new integrated wave prediction system plans to replace the KMA operating model after long-term verification.

• 한국항공운항학회지
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• 제19권1호
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• pp.24-28
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• 2011

This paper reviews a ceiling prediction method based on a mesoscale meteorological modeling system in South Korea. The study was motivated by the tendency of higher model ceiling height than the observed in daily operational forecasts. The goal of the paper is to report an effort to improve the operational ceiling prediction skill by conducting numerical experiments controlling a model parameter. In a case experiment, increasing constant values used in the relationship between extinction coefficients and concentration showed better performance, indicating a short-term strategy for operational local ceiling forecast improvement.

• 한국군사과학기술학회지
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• 제7권3호
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• pp.47-58
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• 2004

This paper focuses on the technical information about the development of the submarine operational effectiveness simulation model for the feasibility study stage of the submarine design. The simulation model is classified into simulation control model and system model. Using user input and related performance parameters, it can simulate various scenarios by no change of the program because it includes tactic manager which makes decision about every situation. And the Monte-Carlo simulation mode which provides the stochastic results is available. Through the test simulation, the usefulness of the simulation model was verified. It should be helpful for the analysis of the submarine operational effectiveness by diversified scenarios in the concept design phase..

• 경영과학
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• 제27권2호
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• pp.31-44
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• 2010

It is very important to forecast demand and determine the optimal procurement quantities of spare parts. The Army has been forecasting demand not with actual usage of spare parts but with request quantities. However, the Army could not purchase all of forecasted demand quantities due to budget limit. Thus, the procurement quantities depend on the item managers' intuition and their meetings. The system currently used contains many problems. This study suggests a new determination procedure; 1) forecasting demand method based on actual usage, 2) determining procurement method through LP model with budge and other constraints. The newly determined quantities of spare parts is verified in the simulation model, that represents the real operational and maintenance situation to measure the operational availability. The result shows that the new forecasting method with actual usage improves the operational availability. Also, the procurement determination with LP improves the operational availability as well.

• 산업공학
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• 제20권4호
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• pp.547-559
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• 2007

In this paper, we design Real-Time Postal Logistics Operational Model and System as a to-be system. Current postal logistics information system, named PostNet, is a basic infra system designed for an end-to-end IT-driven process, from mail acceptance to delivery, linked with internal and external systems. Recent competing circumstances drive demand for more intelligent information system. So we design real-time postal logistics operational system focused on site operations. we analyze postal logistics operation and interview field workers and establish real-time postal logistics operational model to solve operational issues. Finally we suggest system specifications.

• 한국군사과학기술학회지
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• 제22권3호
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• pp.416-424
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• 2019

This paper studies the optimal inventory levels of P-3 assemblies in order to assure the required operational availability. A simulation model is developed for identifying the impact of the inventory levels on operational availability. Based on the result of the simulation model, multiple regression analysis is performed. Finally, the optimal inventory levels of critical P-3 assemblies are determined with integer programming. Additionally, sensitivity analysis of depot maintenance period is also conducted for its impact on the operational availability.

• 경영과학
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• 제31권2호
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• pp.33-48
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• 2014

It is important to maintain on operational availability of aircraft during wartime. The KF-16 fighter, the backbone of the ROKAF (Republic Of Korea Air Force), has a single engine. Therefore, the engine has a critical influence on operational availability. The purpose of this study is to estimate optimal levels of spare part inventories concerning both engines and modules. That is provided by linear programming methods utilizing a developed meta-model. For drawing out the meta-model, we develop a simulation model which can consider wartime demands. In the previous study, $2^k$ factorial design method is used to check the influence of each independent variable. That method requires relatively many scenarios because every extreme value combination of independent variables should be checked. However, this study adopts NOLH (Nearly Orthogonal Latin Hypercube) as an experimental design. By adopting NOLH, this study increases not only efficiency but also accuracy. That is proven by comparing the validity of the developed meta-model on both experimental designs. This study also utilizes the OptQuest simulation tool in ARENA to derive the optimal level of spare stocks. By comparing the result of OptQuest to that of the developed meta-model, the validity of this study is secured.