• Quality Improvement in Health Care
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• v.15 no.2
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• pp.65-71
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• 2009

문제: 환자가 수술장 내에서 수술을 기다리면서 느끼는 불안감을 최소화할 수 있도록 해야 하지만 수술실의 효율성 및 의료진 편의성 위주로 운영되고 있어 수술실 내 대기시간이 연장되고 있다. 목적: 수술장 내 대기시간을 단축시키기 위해 수술환자의 이동경로에 따른 지연요인과 문제점을 파악하고 개선하여 환자가 수술을 기다리면서 느끼는 불안감을 최소화하고자 한다. 의료기관: 부산시에 소재한 481병상의 종합병원 수술실 질 향상 활동: 수술환자의 대기시간 지연요인과 문제점을 파악하고 개선을 통해 질 향상을 도모하였다. 개선효과: 대기시간 수행율에서 수술장 도착까지의 수행율이 개선전 95%에서 개선후98%로, 수술방 입실까지의 수행율이 개선전 88%에서 개선후 94%로, 마취시작까지의 수행율이 개선전 93%에서 개선후 96%로 수행율이 높아졌다.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.425-425
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• 2010

유기 발광 소자는 차세대 디스플레이 소자와 조명 광원으로서 많은 응용성 때문에 활발한 연구가 진행되고 있다. 하지만 청색 유기 발광 소자는 적색과 녹색 유기발광소자들에 비해 상대적으로 발광효율이 낮고 색 순도가 떨어지며 수명이 짧기 때문에 전색 유기발광소자를 구현하는데 문제가 있다. 이런 문제점을 해결하기 위하여 청색 유기 발광소자의 재료 개발, 다층 이종구조 및 형광/인광성 물질의 도핑에 대한 연구가 진행되고 있다. 이와 더불어 색안정성과 색순도가 향상된 진청색 고효율 청색 유기발광소자는 백색유기발광소자의 응용성 때문에 이에 대한 연구가 주목을 받고 있다. 본 연구에서는 청색 유기 발광 소자의 발광효율을 높이고 색안정성과 색순도를 향상하기 위해 4,4'-Bis (2,2'-diphenyl-ethen-1-yl)biphenyl (DPVBi) 와 4,4'-Bis(carbazol-9-yl) biphenyl (CBP)로 구성된 나노크기의 폭을 가진 우물 형태의 이중 발광층 구조를 사용한 청색 유기발광소자를 제작하였다. 제작된 청색유기발광소자의 전기적 성질과 광학적 성질을 조사하여 색안정성 및 색순도 향상 메카니즘을 관찰하였다. DPVBi/CBP 이중 발광층을 가지는 청색 유기발광소자에서 CBP의 HOMO 에너지 준위의 값이 3.2 eV로 매우 크기 때문에 정공을 막는 정공 장벽층의 역할을 하게 되어 정공이 발광층에 머무르게 된다. 또한 DPVBi의 LUMO 값의 크기 5.8 eV, CBP의 LUMO 값의 크기는 6.3 eV이므로 상대적으로 CBP의 전자에 대한 주입장벽이 크기 때문에 발광층에 머무르는 전자의 양이 증가된다. 청색 발광층에 사용된 이중 발광층은 단일 발광층에 비해 더 많은 전자와 정공이 존재하기 때문에 전자-정공 재결합 확률을 높였으며 재결합 영역이 발광층 중심의 이중발광층 계면으로 이동하여 발광 영역이 국소화되어 전압변화에 따른 색의 변화가 적고 색순도가 더욱 향상되었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.278-279
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• 2010

항만컨테이너터미널에서는 컨테이너 생산성뿐만 아니라 하역작업 안전성도 중요하게 고려되고 있다. 생산성 증대를 위해서 도입되는 대형 하역장비의 운영 효율성과 더불어 하역장비를 운영하는 장비기사들의 작업안전성 향상도 중요함에 따라 하역장비기사를 대상으로 하역장비 교육훈련 실시가 필요하게 되었다. 그러나 실제 하역장비운영을 통한 교육훈련은 장비운영비용과 위험성이 수반되기 때문에 경제적으로 장비 운영 시 발생되는 문제점을 최소화시키는 방법 가운데 하나가 항만크레인시뮬레이터를 이용한 하역장비 교육훈련이 제기되고 있다. 이에 본 연구는 교육기관에서 보유하고 있는 실제 항만의 운영환경을 고려하여 개발된 최첨단 장비인 항만크레인시뮬레이터를 이용한 부산항 신항만을 중심으로 하역장비기사 교육현황과 그 성과를 통한 항만크레인시뮬레이터 장비 효율성을 제시하고자 한다.

• Environmental and Resource Economics Review
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• v.20 no.2
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• pp.291-308
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• 2011

The success of a target of 'low-carbon green growth' depends on whether installing energy-saving capital would result in an increase in industry's productivity growth. Defining total factor productivity from a dual cost function, this paper estimates the contribution of energy efficiency investment to productivity growth by analyzing the sources of growth of productivity index for the primary metal industries. Empirical results show that, on average, energy efficiency investment increased the annual rate of productivity growth by 1.16 percentage points over th period 1982~2006. In addition, The scale effect positively affected the contribution of energy efficiency investment on productivity growth.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.165-166
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• 2015

Due to the international economic downturn and the increasing competition, container terminals have been trying to achieve cost effectiveness and high service levels. Shipping companies want to get better services from container terminals but container terminals only have limited space and equipment. Frequently, too many external trucks come to the terminal at the same time, and create bottle necks at the terminals. Ouside the container terminals traffic jams occur as well. As a result, stakeholders need a vehicle booking system. By VBS, container terminals can plan efficiently in advance to avoid work delay and the truck drivers can finish their jobs quickly. This paper aims to search efficient models for the container terminals by using VBS.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.4
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• pp.273-279
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• 2021

Winglets are specialized wingtip devices to reduce induced drag, and they have been installed on Boeing-made aircraft since the 1980s, Airbus has also developed a winglet named 'Sharklet' since 2009 and has started providing them as an option to the A320 Family. The winglet has the effect of improving take-off performance, reducing fuel consumption, increasing payload, and increasing flight distance by reducing the induced drag generated at the tip of the wing. The purpose of this study is to analyze the actual flight data of the sharklet-installed and non-sharklet-installed models of the A321 aircraft to verify the fuel efficiency improvement due to the winglet installation, and to analyze the economic analysis accordingly. Through this, it can be used to determine the winglet installation when introducing an aircraft or to make a decision for upgrading the existing aircraft. To this end, a case study on the aerodynamic characteristics and effects of the winglet installation was conducted, and the economic analysis was verified.

• Industry Promotion Research
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• v.7 no.2
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• pp.59-73
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• 2022

This paper aims to analyze efficiency of sustainable development of foreign trade in eastern China to reduce the input while maintaining the current output level. This paper adopts relevant input-output indicators of 11 provinces in eastern China from 2016 to 2020 and uses DEA to measure comprehensive efficiency, pure technical efficiency, and scale efficiency from the input perspective. Malmquist index was used to calculate MPI. As a result, from 2016 to 2020, the MPI of all provinces in eastern China was 1.035, higher than 1, and the net technology efficiency was 0.911, lower than 1. Overall, the average technological progress index increased 4.5% to 1.045. It can be seen that the sustainable development efficiency of foreign trade has an overall influence on comprehensive efficiency, net technology efficiency, and scale efficiency. The efficiency of sustainable development of foreign trade in eastern China is mainly limited by its scale. The improvement of MPI in the eastern Region mainly benefits from technological progress. For provinces affected by internal factors, it is suggested to strengthen internal coordination. For provinces affected by external factors, it is suggested to respond appropriately to external factors.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.15-25
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• 2005

Using a stochastic cost frontier approach(SCFA), this paper annually estimates the efficiency and productivity with same data in the papers which analyze the efficiency and productivity using data envelopment analysis(DEA) to compare the results and suggest the political findings of raising the efficiency and productivity for three publicly-owned rail transit properties. the Seoul Subway Corporation (SSC), the Seoul Metropolitan Electrified Railways Sector of Korea National Railroad (SMESRS) and the Busan Urban Transit Authority (BUTA). The results show that the results of SCFA are higher than DEA for efficiency and lower for productivity in that DEA regards the stochastic error and measurement error as the inefficiency contrary to SFCA. But the political findings from these results appears to be similar as follows. First, the productivity of the three properties should be first improved by using existing technologies efficiently and then by introducing new ones. Second, the three properties should improve the technical efficiency through reducing input quantities to raise their efficiency. Finally, all the three components of the productivity such as productive efficiency change, technical change, and scale change should be considered to evaluate their productivity more correctly.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1098-1104
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• 2010

Recently, a variety of research of multi-hop routing protocol have been done to balance the sensor node energy consumption of WSN(wireless sensor network) and to improve the node efficiency for extending the life of the entire network. Especially in multi-hop protocol, a variety of models have been concerned to improve energy efficiency and apply in the reality. In multi-hop protocol, we assumption that energy consumption can be adjusted based on the distance between the sensor nodes. However, according to the physical property of the actual WSN, it's hard to establish this assumption. In this dissertation, we propose low-power sub-cluster protocol to improve the energy efficiency based on the spread of distance. Compared with the previous protocols, this proposed protocol can be effectively used in the wireless sensing networks.

• Journal of the Korean Institute of Intelligent Systems
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• v.24 no.2
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• pp.117-122
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• 2014

The minimal pairs mean the pairs that have same phonotactics except just one sound in the sequences cause different lexical items. This paper proposes the searching tool of minimal pairs for efficiency of phonological researches with minimal pairs. We suggest a guide to develop Korean minimal pair searching programs by comparing to other programs. Proposing tool has user-friendly interface, minimizing key inputs, for linguistics who are not fluent in computer programs. And it serves the function which classifies the words in dictionary for the detailed researches. And for efficiency, it increases speed of dictionary loading by separating syllables through Unicode analysis, and optimizes dictionary structure for searching efficiency. The searching algorithm gains in speed by hashing algorithm using syllable counts. In our tool, the speed is improved more than earlier version about 5 times at converting dictionary and about 3 times at searching.