• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.371-374
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• 2007

센서 네트워크에서 효율적인 채널의 사용은 짧은 시간 안에 많은 양의 패킷을 전달하기 위해 중요하며, 채널 활용성을 향상시킨다. 채널 활용성은 MAC 프로토콜의 효율성을 설명하기 위한 좋은 방법이다. 본 논문에서는 효율적인 채널 사용을 위해 B-MAC(Berkeley-MAC)에서 사용한 기법들과 TDMA(Time Division Multiple Access)를 결합시킨 MAC(Media Access Control) 프로토콜을 제안한다. 기본적으로는 backoff, CCA(Clear Channel assessment), LPL(Low Power Listen) 기법 등을 사용하여 충돌과 에너지 소모를 줄이며, 동시에 경쟁 상태에 따라 전송 방식을 다르게 함으로써 채널 활용성을 높이고자 한다. 시뮬레이션을 통하여 기존의 MAC 프로토콜과 비교하여 성능이 향상됨을 보여준다.

• Journal of Nutrition and Health
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• 제27권9호
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• pp.923-929
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• 1994

The effects of vitamin B6 deficiency on energy utilization during fasting or underfeeding were studied in rats. Fifteen rats were fed a vitamin B6 deficient(-B6) diet and another 15 rats wee fed a control (+B6) diet. These rats were fed for 5 weeks with respective diet, and then subdivided into 3 groups : non-fasted group, fasted group, underfed group. Rats of the fasted group were fasted for 3 days and those of underfed group for 6 days. At the respective time (non-fast, 3 day-fast, 6 day-underfeed at 5 weeks), animals were sacrificed. Feed efficiency ratio of - B6 rats was significantly lower than that of +B6 rats. In - B6 rats, the liver and kidney weights were significantly heavier than those of +B6 rats but spleen and heart weights were not. In non-fasted group, liver protein and triglyceride level of - B6 rats were significantly higher than that of +B6 rats. After - B6 rats were fasted for 3 days, plasma free fatty acid level was significantly lower but liver glycogen level was higher than that of +B6 rats and muscle protein level of +B6 was decreased while that of - B6 was not changed. Vitamin B6 deficiency had little effect on the energy utilization with 6 days underfeeding. These results suggest that vitamin B6 deficiency may impair the utilization of stored fuel during fasting.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2002년도 춘계학술대회논문집
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• pp.13-19
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• 2002

In inner harbour of Inchon Port, there are two lock gates (50KT, 10KT) which have two gates per lock gate in inner/outer sides except a gate in inner harbour side 7f 10KT. Due to the lack of the fore-mentioned gate, the use of 10KT lock gate Is suspended in every 3 years for regular maintenance. Now an additional gate is under construction in order to improve the efficiency of the 10KT lock gate. This paper will be aimed to evaluate the operational utilization levels of lock gates in present and future. The present operational utilization levels of lock gates are 0.2119 in 10KT lock gate, 0.2051 in 50KT lock gate which were considered the 46.5 closed days every 3 years for 10KT regular maintenance. The levels are estimated to 0.2246(10KT), 0.2539(50KT) in 2006 and 0.2241(10KT), 0.2560(50KT) in 2011. The levels of 50KT lock gate are evaluated to be more rapidly increased up to 24.5% in 2011.

• 대한임베디드공학회논문지
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• 제6권3호
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• pp.183-189
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• 2011

For the rapid development of embedded software, a variety of development tools have been developed. But, the embedded software developers do not use the available tools fluently and do not improve software productivity as expect because there are short of supporting utilization convenience of development tools. In this paper, we suggest a tool of building custom development environment for improving the utilization convenience of embedded software development tools. The custom development environment helps developers to rapid selection and access of appropriate tools required to develop the embedded software on the specific embedded system. In addition, it enables developers to handle the outputs from development tools associatively. Moreover it is very flexible in extension and integration because it's implementation based on Eclipse technology. We also perform the evaluation of our tool and successfully validate the utilization convenience of embedded development tools. Therefore, we expect that this tool enables developers to use the embedded development tools efficiently, and then it help improving embedded software productivity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.93.1-93.1
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• 2011

To obtain higher power efficiency of Residential Power Generation System(RPG), it is needed to operate system on optimized stoichiometric ratio of fuel and air. In this paper, optimizing stoichiometric ratio of fuel/air is conducted through systematic experiments and modeling. Based on fundamental principles and experimental data, constraints are chosen. Using these stoichiometric ratios as decision variables, maximum power efficiency of system could be found. As a result of research, power efficiency of RPG system is improved.

• 지식경영연구
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• 제3권2호
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• pp.31-48
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• 2002

Recent trend of business is characterized by a recognition of importance of knowledge asset. Especially, this phenomenon is receiving more momentum as our society goes digital rapidly. However, most of literature on knowledge management is based on knowledge circulation from the corporate point of view, not from individual viewpoint. In this regard, this paper is concerned with proposing knowledge circulation process and its efficiency from the individual perspective. We adopted structural equation model or SEM to prove the statistical validity of our research framework. Eight hypotheses were built and tested empirically, leading to the fact that the knowledge utilization and sharing of individuals have a positive impact on the knowledge management efficiency.

• 한국의료질향상학회지
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• 제24권1호
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• pp.30-39
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• 2018

Objectives: In Korea, there are many kinds of evaluations for medical institutions. However, evaluations are increasingly burdensome for medical institutions because evaluation agencies, evaluation timing, and evaluation methods are different. The purpose of this study is to improve the efficiency of evaluation for medical institutions and ultimately to provide quality medical services to patients. Methods: In this study, 2,310 indicators of 19 kinds of evaluation for medical institutions were analyzed. Results: 1,424 indicators were available for on-site surveys and 886 indicators were not available for on-site surveys. There were 4 kinds of evaluation that can be integrated in total, 12 kinds of evaluation that can be integrated partially, and 3 kinds of evaluation that need to maintain the current evaluation system. Conclusion: In order to provide patient-centered quality medical services through reduction of burden due to the evaluation for medical institutions, it is necessary to deeply discuss the efficiency of evaluation integration and result utilization.

• 산업공학
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• 제21권3호
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• pp.302-311
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• 2008

Efficiency evaluation methods of manufacturing processes have relied on absolute measures such as defective rate and throughput per person, ignoring various process characteristics. To overcome the limitation, we propose an evaluation model which reflects characteristics of each process. It is composed of three measures : utilization, performance, and improvement. The suggested model utilizes a combination of DEA and AHP methods. The proposed method has been applied to efficiency evaluation of cellular phone case manufacturing processes.

• STI Policy Review
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• 제2권3호
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• pp.35-44
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• 2011

Korea has rapidly increased R&D investment over the last few decades and the intensity of R&D investment is among the highest in the world; however, there are serious concerns about R&D performance and R&D efficiency. This study is to improve the economic assessment methodology regarding a feasibility study for national R&D programs that are thought to be one of the most prominent ways to enhance R&D efficiency. In order to improve the methodology of economic assessment, a few of important factors such as technical or market uncertainty, spillover effect, and R&D contribution ratio should be covered in the model. The focus of this article is technological and market uncertainty that has a close relation with strategic flexibility and utilization potential to increase the value of R&D programs. To improve the current linear and definitive R&D process, a new framework with strategic flexibility is suggested, in which the result of economic assessment that considers technological and market uncertainty is reflected in planning. That kind of feedback process is expected to enhance the value of the program/project as well as R&D efficiency.

• 산업공학
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• 제14권1호
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• pp.67-78
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• 2001

This paper describes the simulation study which estimates the container crane efficiency in container terminal. In most simulation studies, it is assumed that container cranes are available at any time. Though the failures of container cranes don't occur often, they are very serious problems on terminal efficiency. As usual, the failures of container crane cause arrived ships to delay the departure time. In this study, a queueing simulation model for container terminal, which focuses on the failures of container cranes, is designed. The simulation approach appears to be the most appropriate one because it allows to avoid the usual exponential assumption on interarrivals of ships and service times of container cranes. Using the developed model, we tested the efficiency of container cranes considering failures with a real system size and performed the simulation experiment on real container terminal to validate the developed simulation model. The results of simulation experiment were analyzed using output statistics, which include the waiting times of vessels and yard tractors, the utilization for container cranes, and the berth occupancy rates.