• 한국연소학회:학술대회논문집
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• 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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• pp.58-63
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• 2005

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• 한방안이비인후피부과학회지
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• 제29권4호
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• pp.24-33
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• 2016

Objectives : This study is to investigate the anti-inflammatory and anti-oxidant effects of Tongbi-san extract (TS) on RAW264.7 macrophages using by cell cytotoxicity, Nitric Oxide (NO) and Prostaglandin $E_2$ ($PGE_2$) production and 1,1-diphenyl-2-picryl ghdrazyl (DPPH) free radical scavenging capability. Methods : Cell cytotoxicity was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The production of NO was measured by Griess assay. The production of $PGE_2$ was measured by immunoassay. And the anti-oxidant activity was measured by the DPPH method. Results : TS did not increased significantly compared to the TS untreated group in the cell cytotoxicity. TS inhibited NO and $PGE_2$ production in lipopolysaccharide-stimulated RAW 264.7 cells. TS had the DPPH free radical scavenging capability. Conclusion : The anti-inflammtory and anti-oxidant effects of TS may be use for a treatment of anti-inflammatory diseases.

• Journal of Mechanical Science and Technology
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• 제20권6호
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• pp.864-873
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• 2006

As fuel cells approach commercialization, hydrogen production becomes a critical step in the overall energy conversion pathway. Reforming is a process that produces a hydrogen-rich gas from hydrocarbon fuels. Hydrogen production via autothermal reforming (ATR) is particularly attractive for applications that demand a quick start-up and response time in a compact size. However, further research is required to optimize the performance of autothermal reformers and accurate models of reactor performance must be developed and validated. The design includes the requirement of accommodating a wide range of experimental set ups. Factors considered in the design of the reformer are capability to use multiple fuels, ability to vary stoichiometry, precise temperature and pressure control, implementation of enhancement methods, capability to implement variable catalyst positions and catalyst arrangement, ability to monitor and change reactant mixing, and proper implementation of data acquisition. A model of the system was first developed in order to calculate flowrates, heating, space velocity, and other important parameters needed to select the hardware that comprises the reformer. Predicted performance will be compared to actual data once the reformer construction is completed. This comparison will quantify the accuracy of the model and should point to areas where further model development is required. The end result will be a research tool that allows engineers to optimize hydrogen production via autothermal reformation.

• 품질경영학회지
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• 제23권4호
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• pp.157-166
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• 1995

Process capability indices are used to determine whether a production process is capable of producing items within a specified tolerance. We could estimate the finite sample distributions of some process capability indices with bootstrap method. In this paper, we derive the asymptotic bootstrap distributions of some process capability indices ${\hat{C}}^*_p$, ${\hat{C}}^*_{pk}$ and ${\hat{C}}^*_{pm}$ under general proper conditions. These asymptotic distributiops would be used in constructing some bootstrap confidence intervals. Also, we examine some small sample properties related to these estimators by some simulations.

• 기술혁신연구
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• 제12권2호
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• pp.151-183
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• 2004

This paper investigates the evolution of 'inter-firm' technology transfer in the Thai automobile industry, which has gradually been integrated into global production network of some specific automotive models(one-ton pickups). This paper discusses the linkage between the role of automobile assemblers in transferring technology and the way their strategic changes bring about heightened demands on the technological capacity of suppliers and the contents of technology transfer. With higher competition at the global level, local suppliers are required to improve their technical and managerial skills, especially in the area of 'product engineering' capability. The authors examine the ways local firms have adapted to these changes in their environments, as well as the ways they utilize inter-firm relationship with automobile assemblers as a means to improve their own technological capabilities. The dynamic process of capability formation in local parts firms, through intensive efforts and learning inducements brought about by inter-firm relationships, are also discussed.

• 한국경영공학회지
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• 제23권4호
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• pp.165-177
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• 2018

Smart technology has been utilized in various fields of all kinds of industries. Manufacturing industry has built its smart technology environment appropriate for its manufacturing fields in order to strengthen its manufacturing performance and competitiveness. The advance of smart technology for manufacturing industry needs to efficiently produce products, and response customer's demands and services in a global industrial environment. The smart technology capability of manufacturing fields is very crucial for the innovative production and efficient operation activities, and for efficient advancement of the manufacturing performance. We have necessitated a scientific and objective method that can gauge a smart technology ability in order to manage and strengthen the smart technology ability of manufacturing fields. This research provides a comprehensive framework that can rationally gauge the smart technology capability of manufacturing fields for effectively managing and advancing their smart technology capabilities. In this research, we especially develop a structural framework that can gauge the smart technology capability for a smart factory of manufacturing fields, with verifying by reliability analysis and factor analysis based on previous literature. This study presents a 13-item framework that can measure the smart technology capability for a smart factory of manufacturing fields in a smart technology perspective.

• 한국신뢰성학회지:신뢰성응용연구
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• 제15권4호
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• pp.248-255
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• 2015

Purpose : The purpose of this research is to develop the optimized method and process in the reliability-growth target setting, especially for complex and repairable system (or products) such as vehicle and airplane, construction equipment. Method : A reliability-growth test plan specifies a scenario to achieve the planned reliability value (or reliability target). The major elements in test planning are reliability-growth starting time and reliability level at that time, reliability-growth rate and reliability-growth target. All of them except a reliability target can be referred to the previous development data and reference researches. The reliability target level is directly influencing to test period (or time) which is related to test and warranty cost together. There are a few researches about the reliability target setting method and but showing the limitations to consider the views of engineering, business and customer together. There is no research how to handle the target setting process in detail. Result : We develop the optimized method and systematic process in reliability target setting with considering such views. This research also establish the new concept as production capability which means company (or supplier) capability to product its products. Conclusion : In this research result, we apply the new method to a few projects and can set the reasonable test planning. The developing results is showing the good balance between the developing cost and warranty cost at market.

• 대한치과기공학회지
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• 제40권3호
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• pp.151-162
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• 2018

Purpose: The main purpose of this study is to develop assessment measures for the quality of service for dental labs. Methods: In order to construct the measure of service quality assessment for dental labs, relevant modifications were extracted around theoretical studies, and the survey was conducted on dental technician workers through internet survey. final scale questions were extracted through exploratory factor analysis and confirmed factor analysis of measurement variables, the demographic characteristics of the subjects and the perceptual difference of dental labs were analyzed for the extracted variables. Results: The final five variants of the interactive factor analysis that include the ability to change employee growth, reliability, responsiveness, materiality, interoperability, confirmatory factor analysis excludes variations in employee growth wages, welfare benefits, by changing its name to network capabilities, the quality of service factors for the final dental labs consisted of five variations: network competence, reliability, responsiveness, materiality and interoperability. Conclusion : The service quality of the dental labs showed that the reliability of the product related to the dental materials and the product production responsiveness related to the production order, the Materiality of the materials and equipment of the dental labs, the Interoperability responsiveness related to dental orders, And the importance of network capability to form a mutual network.

• Journal of the Korean Data and Information Science Society
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• 제21권6호
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• pp.1051-1060
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• 2010

도금공정에서는 도금두께의 규격한계는 주어지지만 대부분의 경우 목표치는 주어지지 않는다. 목표치가 주어지지 않았을 때 일반적으로 규격의 중심점이 목표치로 사용된다. 하지만 공정능력치가 크다면 규격의 중심을 목표치로 사용하는 것은 총 손실비용면에서 최선의 선택이 아니다. 이 논문에서는 총 손실비용을 생산비용과 손실함수의 합으로 정의하였고 기대 총 손실비용을 최소화 하는 목표치를 제안하였다. 그리고 그때의 공정능력치의 감소가 미미한 것을 보였다.

• Korean Journal of Acupuncture
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• 제32권4호
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• pp.169-176
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• 2015

목적 : 한의학에서 골절이나 신장질환에 사용되어 왔던 골쇄보열수추출물 약침액이 항염증 및 항산화활성에 대한 효능이 있는지를 연구하고자 한다. 방법 : 골쇄보열수추출물 약침액이 세포독성에 미치는 영향을 관찰하기 위하여 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay를 실시하였다. 골쇄보열수추출물 약침액이 항염증효능에 미치는 영향을 관찰하기 위하여 lipopolysaccharide(LPS)로 유도된 RAW264.7 대식세포에서의 산화질소(NO) 및 프로스타글란딘($PGE_2$) 생성 억제력을 관찰하였다. 또한 골쇄보열수추출물 약침액이 항산화활성에 미치는 영향을 관찰하기 위하여 1,1-diphenyl-2-pciry hydrazyl(DPPH) radical 소거능을 관찰하였다. 결과 : 골쇄보열수추출물 약침액은 $50{\sim}400{\mu}g/ml$ 농도에서 세포독성이 나타나지 않았다. 골쇄보열수추출물 약침액은 200 및 $400{\mu}g/ml$ 농도에서 LPS로 유도된 NO 및 $PGE_2$ 생성을 통계학적으로 유의하게 감소시켰다. 골쇄보추출물은 $50{\sim}400{\mu}g/ml$ 농도에서 DPPH 소거능을 관찰한 결과 농도의존적으로 활성화되는 것을 관찰하였다. 결론 : 골쇄보열수추출물 약침액은 항염증 및 항산화 효과가 있을 것으로 사료된다.