• Environmental and Resource Economics Review
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• v.23 no.3
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• pp.365-408
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• 2014

The purpose of this paper is to compare efficiencies, two stage efficiencies, and the reduction of economic growth due to the restraint of $CO_2$ and fossil fuel in two efficiency approach by pointing out the limit of traditional efficiency approach and introducing material balance approach. The efficiencies under the traditional approach and the material balance approach report significant gaps when they are analyzed in detail. Especially, in case not including fossil fuels, the low income countries show the bad performance of production efficiencies, but OECD and high-middle income countries reveal the better performance than that of the low countries. It fails to reflect the reality justly. Based on the material balance approach, the low income countries report the higher performance and the alleviated effect of environmental components for economic growth than OECD's.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.472-472
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• 2012

유기발광소자는 빠른 응답속도, 높은 색재현성, 높은 명암비의 장점을 가지고 있어 차세대 디스플레이로 각광 받고 있으며, 이미 소형 디스플레이로 상용화되고 있다. 유기발광소자에서는 발광효율을 높이기 위해서 전하들의 균형이 매우 중요하다. 유기발광소자 내 정공의 이동도는 전자의 이동도보다 빠르기 때문에 정공의 이동도를 감소하거나, 전자의 이동도를 증가하여 전하들의 균형을 형성함으로 유기발광소자의 효율을 증진시키는 연구가 진행되고 있다. 본 연구는 유기발광소자의 전자 수송층을 다층구조로 적층하여 전자의 이동도를 증가하여 효율이 증진하는 메커니즘을 기본으로 하였다. 전자 수송층을 tris(8-hydroxyquinoloine)aluminum ($Alq_3$) 단일층, 4,7-diphenyl-1, 10-phenanthroline (BPhen)과 $Alq_3$의 혼합층및 BPhen과 $Alq_3$ 다층 구조로 제작한 유기발광소자의 전기적, 발광 특성을 비교 분석하였다. BPhen은 lowest unoccupied molecular orbital (LUMO) 준위가 $Alq_3$의 LUMO 준위와 유사하여 전자 주입이 효율적으로 일어나며, 또한 낮은 highest occupied molecular orbital (HOMO) 준위는 정공 저지층의 역할을 하여 발광층 내에서 전하의 균형을 효율적으로 맞춰준다. 유기발광소자는 N,N,'-bis-(1-naphthyl)-N,N'-diphenyl1-1'-biphenyl-4,4'-diamine (NPB)/ $Alq_3$/ 다양한 전자수송층 / lithium quinolate (Liq)/ aluminium (Al) 음극 전극으로 각각 증착하여 제작하였다. 전자수송층을 다층 구조로 사용한 유기발광소자는 발광효율이 혼합층과 단일층에 비해 높았으며, 최대 발광효율은 전류밀도가 273 mA/cm2일때 4.5 cd/A였다. 다층구조의 전자수송층에서 다층으로 증착된 BPhen이 효율적인 전자 주입 및 전공 저지하는 역할을 최적화 하여 발광층에 더 많은 엑시톤이 형성하여, 유기발광소자의 효율을 증진시켜 준다는 사실을 알 수 있었다.

• Korean Security Journal
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• no.19
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• pp.67-103
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• 2009

Objectives of this study is develop security services through determinants analysis on the efficiency of security works regarding security and guarding business in Korea because nowadays the modern society like Korea let alone all over the world faces the increase of dangerous factors in every security field of the human societies, and also it is the very present situation that an individual's life even the national security itself can be at the risk without guaranteeing the efficiency of the security services. For this purpose, this study reviewed related documents, surveyed and interviewed security personnels to identify what the potentially influential factors are in both the public and private security organizations regarding the efficiency of present security services and organizations, and what differences are. Also, comparing the public and private security sectors, this study intended to suggest policy agendas how to enhance the efficiency of security services in the future. This study surveyed the 177 agents and former agents of the Presidential Security Service(PSS) for the public security sector, and also surveyed, interviewed, and internet-based polled 821 randomly selected personnels for the private security sector. This research showed that regarding the efficiency of the security services number of independent variables which had positive responses in the public security sector was more than that in the private security sector. Among the 21 questions regarding this issue, there were all of 21 positive responses in the public security sector while there were 18 negative responses in the private security sector. As a result of synthesizing all the answers of the both sides, it is possible to understand that mostly the ratio of the positive response was much higher. In the public security service, statistically significant variables were budget support for events, prior access of information, an integrated teamwork training, organizational atmosphere, morale of organization personnel. However, practical training of the security service and mutual communication showed unexpectedly negative(-) signs. In the private security service, statistically significant variables were budget support for events, integrated teamwork training, socially friendly atmosphere, compensation for the personnels, bullet-proof equipments and vehicles, mood of organization, personnel recruit and disposition, unexpected incidents and basic attitude for security services. In sum, while organizational personnel variables and organizational management variables were significant in the public security service, some organizational management variables and all socio-environment variables were statistically significant at 5% significance level.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.1
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• pp.143-148
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• 2013

In this study, the elements related to defense and military facilities prior military to conduct business the previous business and the locals want what empirical thought and professionalism and most importantly, accountability and efficiency was a result of the relative effort performance communicationelements to be considered only with comparable importance in the analysis was If you are promoting a business in the Defense Department and other relevant departments to reflect this shall be deemed to be working with residents and business to reduce conflict.

• The Journal of the Korea Contents Association
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• v.20 no.4
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• pp.564-570
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• 2020

The development of cloud computing service technologies plays a particularly important role in the enterprise. The introduction of cloud computing services by companies is also contributing to the improvement of market value and changes in corporate earnings. In this study, we demonstrated the importance of priorities by selecting sub-items that can be evaluated by separating the expected characteristics of efficiency, economics, and dependencies when introducing cloud computing services. The main priority items were selected based on prior research and the survey was conducted by IT system experts. Using AHP analysis method, the results of performing a double contrast bridge resulted in the final priority. The findings will later be used as important data to determine an enterprise's decision to accept cloud computing services.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.1
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• pp.51-59
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• 2005

SLSV (single loop single vector) method is to solve the excessive computational cost problem in RBDO (reliability-based design optimization) by decoupling the nested iteration loops. However, the practical use of SLSV method to RBDO case is limited by the instability or inaccuracy of the method since it often diverges or converges to a wrong solution. Thus, in this paper, a new modified SLSV method is proposed. This method improves its convergence capability effectively by utilizing Inactive Design and Active MPP Design together with modified HMV (hybrid mean value) method. The usefulness of the proposed method is also verified through numerical examples.

• Proceedings of the Korean Information Science Society Conference
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• 2012.06d
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• pp.308-310
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• 2012

최근 무선 센서 네트워크 환경에서 대용량 멀티미디어 데이터에 대한 요구가 증가하면서 통신 대역폭 및 한정적인 에너지의 한계를 극복하기 위한 대안으로 데이터 분할 및 다중 경로 기법들이 제안되었다. 기존 기법들은 데이터 전송 시에 발생하는 부하의 분산을 통해 네트워크의 성능을 향상시킬 수 있다는 것을 증명하였지만, 데이터의 효율적인 분할과 악의적인 공격에 의한 보안성 문제에 대해서 고려하지 않았다. 이러한 문제점을 해결하기 위해 본 논문에서는 비트평면 분할 기반의 보안성 있는 비-중첩 다중경로 라우팅 기법을 제안한다. 제안하는 기법은 멀티미디어 데이터를 비트평면 단위로 분할하여 다중 경로로 전송함으로써 기존의 키 기반의 암호화 기법을 사용하지 않고도 전체 네트워크에 대한 보안성을 향상 시켰다. 또한 경로 상 노드들의 잔여 에너지를 고려하여 데이터 전송을 수행함으로써 전체 네트워크의 에너지 효율성을 향상시켰다. 성능평가 결과, 제안하는 기법은 기존 기법에 비해 노드의 생존율이 평균 50% 이상 향상되었고, 데이터가 노출되더라도 해당 패킷을 가지고 본래 이미지를 복구하는 것이 불가능하기 때문에 높은 보안성을 제공한다.

• Journal of the Korea Society of Computer and Information
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• v.8 no.4
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• pp.138-147
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• 2003

There are some problems of current internet protocols to support the mobility of terminal in wireless environments. The mobile IP has come out to solve these problems, but there exists some problems like triangle routing, the need of each host's home address and the management of tunneling. Also. real-time multimedia traffics require fast hand-off, low latency and the utilization ratio of high bandwidth. SIP can support the mobility of wireless terminal and is widely accepted as the protocol which can support multimedia service and call setup in next generation network. In this paper, the framework of SIP system will be designed and implemented to support the mobility of wireless terminal by using JAIN API which follow the standards of next generation network and this system matches the standards of next generation network.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.217-224
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• 2011

Existing wire based physical security system solutions show limitations in time and space. In order to solve these deficiencies, a remote physical security system has been implemented using smart phone based on mobile cloud computing technique. The security functions of mobile cloud computing technique include mobile device user authentication, confidentiality of communication, integrity of information, availability of system, and target system access control, authority management and secure hand off etc. Proposed system has been constructed as remote building management system using smart phone, and also has been efficient to reduce energy cost (5~30%), result of system average access and response time 7.082 second. This systems are evaluated to have high efficiency compared to performance.

• Journal of Internet Computing and Services
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• v.8 no.3
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• pp.57-63
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• 2007

Providing the sufficient energy to the mobile device is essential to process the job in distributed wireless network. To solve the restrained conditions of energy problems of mobile devices, this paper suggests the efficient method of processing the distributed job using mobility management in wireless network. Energy consumption can be analyzed using the statistical model and required energy of processing the distributed job in mobile device can be predicted using the mobility management. Therefore, this paper suggests the reliable algorithm to process distributed job through the mobile devices with regular mobility and shows the efficiency of the suggested algorithm.