• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.510-514
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• 2008

본 연구에서는 전극의 특성에 따른 돈사유래 축산폐수의 ECO 공법에 의한 처리특성을 평가하기 위해 ECO 시스템 모듈내 Fe-Fe 및 Al-Al 계열의 용해성 전극과 Al-SUS, Ir-SUS 등 불용성 전극을 대상으로 5$\sim$20mA/cm$^2$의 전류밀도하에서 축산폐수내 유기물 및 영양염류의 제거특성을 평가하여 다음과 같은 결론을 얻을 수 있었다. 1. 전기응집산화에 의한 축산폐수의 처리시 수중 유기물질 및 영양염류의 제거효율은 전류밀도의 증가에 비례하여 증가한다. 2. 불용성 전극조합 및 불용성-용해성 전극조합은 전류밀도가 높을수록 수중 유기물 및 오염물질 제거효율이 안정되고, 용해성 전극은 15mA/cm$^2$ 이하의 저 전류밀도의 조건하에서 전류밀도의 증가에 따라 안정된 제거효율 향상을 기대할 수 있다. 3. 불용성전극 조합인 Ir-SUS 전극조합을 사용하여 축산폐수를 처리할 경우 COD$_{Mn}$ 제거효율을 약 10% 향상시킬 수 있으며, TN 20mA/cm$^2$에서 Al-Al 전극조합과 TP 15mA/cm$^2$ 이하에서 Fe-Fe 전극조합은 제거효율이 저하되는 경향이 나타난다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.3
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• pp.42-47
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• 2016

The quality of CAD models affects the efficiency of the product development process. However, it seems that CAD modeling education in colleges simply focuses on the creation of CAD models without considering the quality or the applicability of the models. In this paper, we propose educational modeling approaches to help improve the quality and applicability of CAD models. These methods teach students to create models that include a rich set of information, facilitate downstream applications, and are precisely made with the fewest operations. A survey was carried out with students to validate these approaches.

• Journal of the military operations research society of Korea
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• v.36 no.3
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• pp.29-42
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• 2010

In this study, the weapon-target assignment problem arising in military application of operations research is considered. We reformulated the problem in order to simplify the solution methods based on genetic algorithms and heuristics. Since the problem is well known as NP-complete and cannot be solved in polynomial time, such solution methods have been widely used to obtain good solutions. Two chromosome representations--target number representation and permutation representation--in genetic algorithm are compared. In addition, a construction heuristic and three improving heuristics are developed. Several experiments under the condition of transitivity rules in weapon's kill probability have been accomplished. It shows that the construction heuristic and exchange-based improving heuristic guarantees good solutions within a second and the performance of construction heuristic is sensitive to transitivity rules.

• Knowledge Management Research
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• v.22 no.4
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• pp.237-260
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• 2021

This study aims to make suggestions for more effective budget utilization and R&D project investment through verification of the efficiency of research results for the government's R&D projects. Efficiency was analyzed using Data Envelope Analysis(DEA) and 'Malmquist Index analysis' for the research results of convergence research projects organized by the National Science and Technology Research Association. The analysis targets were convergence research projects organized by the National Science and Technology Research Association and general entrusted research projects by government-funded research institutes, and dynamic analysis was conducted using DEA and Malmquist Index analysis. As a result of the analysis, the convergence research project showed high efficiency from the static perspective of DEA. On the other hand, from a dynamic perspective through the Malmquist Index analysis method, the efficiency of the general consignment project gradually declined, while the efficiency of the convergence research project improved every year. This suggests that convergence studies have higher results than general studies. Through the results of this study, we intend to present objective standards for performance evaluation of government R&D investment and provide objective implications for rational investment policies and research project planning of research personnel and research funds to improve efficiency for government-funded research institutes.

• Convergence Security Journal
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• v.16 no.2
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• pp.3-9
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• 2016

Recently, a lot of researches have been done to increase the life span of network using the energy efficient sensor node in WSN. In the WSN environment, we must use limited amount of energy and hardware. Therefore, it is necessary to design energy efficient communication protocol and use limited resources. Cluster based routing method such as LEACH and HEED get the energy efficient routing using data communication between cluster head and related member nodes. In this paper, we propose an energy efficient routing algorithm as well as performance result using simulation.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.5
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• pp.983-989
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• 2012

IEEE 802.3az LPI mechanism allows an Ethernet link to reduce power consumption by entering a low-power sleeping mode and letting some components being powered off when there is no data to be transmitted through the link. However, if small amount of packets are being sent periodically, such a mechanism can not obtain energy efficiency due to a high overhead caused by excessive mode transitions. In this paper, we propose an enhanced LPI mechanism which can perform state transition adaptively based on the traffic characteristics on transport layer and network status. This simulation result shows that proposed mechanism improves energy efficiency than LPI mechanism with respect to energy consumption rate for various traffic loads.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.279-288
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• 2010

지식기반 경제 사회의 진입과 더불어 조직에서 가장 중요한 요소는 인적자원이며 인적자원의 효율적인 활용이야말로 기업 경영에 있어서 핵심이라고 할 수 있다. 이러한 인적자원의 역량을 향상시킬 수 있는 방법으로 대부분의 기업들은 교육훈련을 실시하고 있다. 교육훈련의 효율적인 활용이야말로 인적자원의 개발이고, 인적자원의 개발이 기업의 지속가능한 경영에 가장 중요한 부분이라고 할 수 있다. 인적자원 개발을 위한 교육훈련이 조직의 발전에 최우선이 되어야 함은 아무리 강조해도 지나침이 없다. 기업에 있어서 사람이 자산인데 자산을 키우기 위한 최선의 방법으로도 기업들은 효율적인 교육 훈련에 많은 연구를 실시하고 있다. 인적자원이 기업의 성패를 좌우할 만큼 중요한 핵심요소이고 기업의 핵심인 인적자원을 개발하기 위해선 교육 훈련이 핵심이고 핵심인 교육훈련은 기업의 인적자원개발에 대부분을 차지하고 있다고 해도 과언이 아닐 것이다. 따라서 본 연구의 목적은 기업교육의 효율성을 제고하기 위하여 HRD 요소들에 있어서 조직원 직무향상을 위한 교육효과에 초점을 맞추었다. 교육훈련에 관한 요인분석 결과 교육의 중요성인지, 교육 참가횟수, 교육내용 등의 사전인지가 교육의 효과를 높이는 요인으로 나와 있고, 이러한 결과를 토대로 회귀모형 분석을 제시하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.5
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• pp.429-436
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• 2017

Since the telemetry performance using the time-delayed data dissipates the wireless channel resources, we propose the spectral efficient retransmission scheme in this paper. In the proposed scheme, the telemetry data is retransmitted based on triggered memory to improve the spectral efficiency. The proposed scheme minimizes the error caused by multipath fading, antenna pattern as well as the error caused by the flight events. In the flight simulation data, we show the proposed scheme improves the telemetry performance based on spectral efficient retransmission.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1119-1125
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• 2010

Most of the sludge pre-treatment methods to improve the anaerobic digestibility of sludge are not practied in the fields with low economical efficiency. The venturi cavitation system (VCS) adopting hydrodynamic cavitation is simple and requires low energy. This research was conducted to investigate the optimum design and operating conditions of the VCS. The experimental results indicated that the optimum number of venturi in series was three, and the suction mode operation of the pump yielded 1.6 times higher pre-treatment efficiency per unit energy consumption than the discharge mode. The combination of venturies with different throat sizes did not affect the pre-treatment efficiency. Also, the parallel installation of the three in series venture unit yielded 30% higher pre-treatment efficiency per unit energy consumption than the single unit. Under parallel conditions, the solubilization efficiency was 5.6 mg ${\Delta}SCOD/g$ TS/kWh, which is higher than the previously reported value.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.305-312
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• 2012

This paper aims at improving the accuracy and computational efficiency in reconstructing building boundaries from airborne Lidar points. We proposed an adaptive convex hull algorithm, which is a modified version of local convex hull algorithm in three ways. The candidate points for boundary are first selected to improve efficiency depending on their local density. Second, a searching-space is adjusted adaptively, based on raw data structure, to extract boundary points more robustly. Third, distance between two points and their IDs are utilized in detecting the seed points of inner boundary to distinguish between inner yards and inner holes due to errors or occlusions. The practicability of the approach were evaluated on two urban areas where various buildings exist. The proposed method showed less shape-dissimilarity(8.5%) and proved to be two times more efficient than the other method.