• 경영과학
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• 제34권3호
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• pp.1-14
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• 2017

This study empirically analyzes the impact of inventory management performance on the energy efficiency in Korean petrochemical companies. The concept of the distance function is used to define the energy efficiency and the estimation of the distance function is performed using the stochastic frontier analysis. The inventory turnover is selected as the variable indicating the inventory management performance of the company. The main results of this study are as follows. First, the inventory turnover has a positive impact on energy efficiency. Second, during the period over 2011~2015, while the gap in energy efficiency among the companies expanded, the average energy efficiency decreased. Third, the average energy efficiency in upstream process companies was greater than downstream process companies and the gap in energy efficiency among downstream process companies was greater than upstream process companies. Fourth, the average marginal effect of inventory turnover on energy efficiency increased gradually from 2011 to 2015. Finally, the average marginal effect of inventory turnover in downstream process companies was greater than upstream process companies, and the gap in the marginal effect of inventory turnover among downstream process companies was greater than upstream process companies. These results together imply the importance of inventory management in terms of energy efficiency.

• 한국기계가공학회지
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• 제11권5호
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• pp.54-59
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• 2012

This study dealt with effect of the grinding in SCM420H planetary gears. The hardness, tooth profile, lead and roughness of the gear surface can be improved by grinding process. Therein, the grinding techniques are widely used especially as one of the physical surface improvement methods. As the results, the gear grinding process reduced vibration and noise, and increased the life of the gear. And the gear grinding improved the surface of gear tooth in a short time and low cost, thus, it is a very important process in manufacturing industry. But nowadays, it is hard to find the detail information of gear grinding process. The test piece is a planetary gear which is used in the industrial machine. The manufacture process of the test piece contains hobbing, shaving, carburizing and grinding. This study investigated the effect of the grinding process to the physiognomy and the fatigue strength of test piece which was made by SCM420H.

• International Journal of Air-Conditioning and Refrigeration
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• 제6권
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• pp.113-123
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• 1998

The present study is to investigate the effect of experimental parameters on the heat transfer characteristics of a spherical capsule storage system using paraffins. N-Tetradecane and mixture of n-Tetradecane 40% and n-Hexadecane 60% were used as paraffins. Water with inorganic material was also tested for the comparison. The experimental parameters were varied for the Reynolds number from 8 to 16 and for the inlet temperature from -7 to 2$^{\circ}C$. Measured local temperatures of spherical capsules in the storage tank were utilized to calculate charging and discharging times, dimensionless thermal storage amount, and the average heat transfer coefficients in the tank. Local charging and discharging times in the storage tank were significantly different. The effect of inlet temperature on charging time was larger than that on discharging time, but the effect of Reynolds number on charging time was smaller than that on discharging time. Charging time of paraffins was faster by 11~72% than that of water with inorganic material, but little difference of discharging time was found among them. The effect of Reynolds number on the dimensionless thermal storage was less during charging process and more during discharging process than the effect of inlet temperature. The effect of the inlet temperature and the Reynolds number on the average heat transfer coefficient of the storage tank was stronger during discharging process than during charging process. The average heat transfer coefficients of the spherical capsule system using paraffins were larger by 40% than those using water.

• 시스템엔지니어링학술지
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• 제5권1호
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• pp.57-65
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• 2009

The purpose of Defense Acquisition Project is that the superior weapons validated needs and performance are supplied to military user with limited financial resources and time. The Warship Acquisition Project is not only like this, But also has special characteristics of long project period and first-constructed ship's operation employment. So, The Warship Acquisition Project need systematic and efficient procedure & management. And this paper researches System engineering application of imaginary WIG(Wing-In-Ground Effect) ship acquisition project based Systems Engineering Handbook ver.3.1 published by INCOSE, the lead of field. The Imaginary WIG(Wing-In-Ground Effect) ship acquisition project applied the four processes(technical project, Enterprise & Agreement, Enabling Systems), the basis of INCOSE Engineering Handbook ver.3.1, and the each process output compared with DAPA(Defense Acquisition Program Administration)'s warship acquisition procedure.

• Management Science and Financial Engineering
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• 제9권2호
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• pp.21-45
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• 2003

Various organizational factors effect successful implementation of IT enabled business transformation. Among them, the most critical success factor is deemed to overcoming change management problem. Lots of studies have been made on implementation methodologies and business process formalizations to encourage organizational members to accept new business process changes. However, the logic of process redesign still depends on qualitative problem solving techniques mostly depending on basically human intuition such as brainstorming, cause-and-effect analysis, and so on. In this paper, we develop algorithmic procedure applicable to designing various business process changes such as process automation, business process resequencing, and more radical process integration. The framework is employed from dynamic programming approach in the literature, which is based on the decision making paradigm of organizations to abstract business processes as quantitative decision models. As such, our research can fill the gap of limited development of theory based analytic methodologies for business process design, by providing objective rationale to reach the consensus among the organizational members including senior management.

• 한국전기전자재료학회논문지
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• 제20권4호
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• pp.303-307
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• 2007

This paper investigated the effect of the pad buffing process on the material removal characteristics and pad stabilization during silicon chemical mechanical polishing. The pads surface were controlled by the buffing process using a buffer made by the sandpaper. The buffing process is based on abrasive machining by using a high speed sandpaper. The controlled pad by the buffing process show less deformation deviation and stable material removal rate during the CMP process. In addition, the controlled pad ensure better uniformity of removal rate than comparative pads. As a result of monitoring, the controlled pad by the buffing process demonstrated constant and stable friction force signals from initial polishing stage. Therefore, the tufting process could control the pad surface to be uniform and improve the performance of the polishing pad.

• 생약학회지
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• 제44권1호
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• pp.41-46
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• 2013

Alzheimer's disease (AD), most common form of dementia is characterized that memory deficit and loss of cognitive function. The Codonopsis lanceolata (C.lanceolata) was treated by high hydrostatic pressure process and fermentation. This study was evaluated cognitive enhancing effect C.lanceolata extract by high hydrostatic pressure process and fermentation and compared with common C.lanceolata extract using Morris water maze and passive avoidance test. And their neuroprotective effect on glutamate induced oxidative stress in HT22 cell was investigated by MTT assay. High hydrostatic pressure process and fermented C.lanceolata extract (HFCE) and common C.lanceolata extract (CCE) (100 and 300 mg/kg) were administered to mice. Results showed HFCE enhanced cognitive function than CCE as shown by decrease in escape latency time. HFCE increased the latency time of the passive avoidance test compared to CCE. Furthermore, HFCE showed significant neuroprotective effect against glutamate cytotoxicity in HT22 cells. These results indicate that high hydrostatic pressure process and fermented more improve spatial cognitive ability of C. laanceolata.

• 공업화학
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• 제23권5호
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• pp.490-495
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• 2012

오존/활성탄 공정을 이용하여 페놀을 처리 할 경우, 활성탄에 의해 나타나는 촉매효과에 관한 연구를 수행하였다. 오존 단독공정에 활성탄을 추가할 경우, 활성탄 투입량이 증가할수록 용존 오존 및 페놀의 분해효율이 증가하는 것으로 나타났다. 이는 활성탄에 의해서 용존 오존이 분해되어 생성된 수산화 라디칼이 페놀 제거에 영향을 미쳤으며, 본 연구에서는 활성탄의 촉매효과([$\Delta$phenol] / $[{\Delta}O_{3}]_{AC}$)로 나타내었다. 활성탄 10~40 g/L 투입 시, 모든 활성탄의 최대 촉매효과 값은 $2.0\;{\pm}\;0.1$로 나타났지만, 10 g/L와 20 g/L를 투입한 경우, 40 min 경과 후 최대 촉매효과에 근접한 반면, 활성탄 30 g/L와 40 g/L를 투입한 경우, 반응 20 min 경과 후 최대 촉매효과에 도달하였다. 또한 Total Organic Carbon (TOC, 총유기탄소)의 제거율은 오존 단독공정에서 0.23으로 나타났으며, 오존/활성탄 공정에서는 0.63으로 나타났다.

• 경영과학
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• 제10권2호
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• pp.111-120
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• 1993

The most important factors for a product to survive in the market are cost and quality. In recent years, quality proceeds to cost. There are many techniques of use to improve the quality of a product. One of the techniques is applying statistical methods (especially Taguchi method) to real operational conditions for a continuous manufacturing process in P company. There are 91 factors to control in the process. So, we predetermined 7 main effect factors and 6 interactive effect factors by statistical methods and advices of engineers. With these 13 factors, we determined the optimal level of operations for the process.

• 한국산학기술학회논문지
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• 제13권11호
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• pp.5098-5103
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• 2012

본 연구는 고객관계 역량을 높이기 위해 정보시스템의 역할을 내부 프로세스 역량과 기업 내의 커뮤니케이션을 통하여 고찰하였다. 내부고객의 업무효율성을 개선하여 외부고객의 만족도를 높이는 방향으로 정보시스템의 역할을 살펴보았다. 본 연구에서는 한국직업능력개발원에서 제공한 인적자본 기업패널 자료 중 정보시스템 활용, 커뮤니케이션, 내부 프로세스 역량 및 고객관계 역량 변수를 사용하였으며 연구 결과, 정보시스템의 활용은 내부 커뮤니케이션과 프로세스 역량을 증가시키고 내부 프로세스 역량은 고객관계 역량에 정(+)의 영향을 미치고, 커뮤니케이션은 내부 프로세스 역량을 향상시키는 것으로 제시되었다.