• 대한토목학회논문집
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• 제41권4호
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• pp.387-397
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• 2021

우리나라 농업용수 공급은 대부분 저수지를 통한 공급 방법을 채택하고 있어 그 의존도가 매우 높다. 이에 적용 가능한 대체 수원을 활용하여 저수지 의존도를 경감시키고 안정적인 농업용수 공급이 이루어져야 한다. 따라서, 본 연구에서는 토지이용 별 시나리오를 구성하여 대체 수원인 빗물과 하수재이용수를 활용한 최적의 용수공급방안에 대하여 분석하고 빗물 이용시설의 최적 용량을 결정하는 연구를 수행하였다. 분석 결과 기존 논농사 지역을 하우스로 변경하여 빗물을 최대로 활용할 경우 안정적인 공급이 이루어졌고, 실제 빗물을 활용하고 있는 농장에서 1 mm의 강우에 약 0.82 ton의 용량이 필요한 것으로 분석되었다. 이에 최적의 시나리오를 MODSIM을 통해 결정한 빗물 저류 용량과 실제 모니터링을 통해 결정한 저류 용량을 집수면적당 저류 용량 비율로 분석한 결과 각각 약 31, 32 %로 유사하게 나타났으며, 빗물 이용시설의 최적 용량은 약 5,796,000 ton ~ 6,182,400 ton 으로 분석되었다.

• Journal of Electrical Engineering and Technology
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• 제10권4호
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• pp.1492-1501
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• 2015

This paper analyzes the effect of voltage sag on distribution systems due to the connection of Electric Vehicles (EVs). In order to study the impact of the voltage sag on the power system, two scenarios have been selected in this paper. The distribution system and EVs are modeled using the Electro Magnetic Transients Program (EMTP). The numbers of EVs are predicted based on the number of vehicles in distribution system of Seoul. In addition, the number of EVs is set up using real-time traffic in Seoul to simulate Scenario I and II. The simulation results show that voltage sag can occur if the distribution system has more than 30% of the total number of vehicles.

• 한국농공학회논문집
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• 제55권2호
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• pp.9-20
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• 2013

Many studies have reported additional treatment is needed to use wastewater for agricultural purpose. Economic considerations should be taken into account to establish infrastructure for agricultural reuse because of a large amount of water use in irrigation and relatively low water quality requirement. The objective of this study was to conduct economic analysis of wastewater reclamation and reuse systems for agriculture. A system dynamics approach considering complexity and dynamics in the wastewater reuse systems was used for the economic analysis, which are related with social, environmental, and economic problems. Sensitivity and benefit cost analysis for wastewater reuse systems was conducted through the established economic assessment model. The result of sensitivity analysis showed that water resources development and installation cost were the most sensitive for total benefits and costs, respectively. The scenario-based test of the organized economic assessment model shows marginal cost ranges and enables decision-makers to decide reasonable cost for the wastewater reuse systems for agriculture.

• 한국농공학회논문집
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• 제62권2호
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• pp.1-15
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• 2020

In this study, the characteristics of crop damage area by flooding for 113 middle range watersheds during 2000-2016 were analyzed and future crop damage area by flooding were analyzed using 13 GCM outputs such as hourly maximum rainfall, 10-min maximum rainfall, number of days of 80 mm/day, daily rainfall maximum, annual rainfall amount associated with RCP 4.5 and RCP 8.5 scenarios and watershed characteristic data such as DEM, urbanization ratio, population density, asset density, road improvement ratio, river improvement ratio, drainage system improvement ratio, pumping capacity, detention basin capacity, and crop damage area by flooding. A constrained multiple linear regression model was used to construct the relationships between the crop damage area by flooding and other variables. Future flood index related to crop damage may mainly increase in the Mankyung watershed, Southwest part of Youngsan and Sumjin river basin and Southern part of Nackdong river basin. Results are useful to identify watersheds which need to establish strategies for responding to future flood damage.

• 한국공간정보시스템학회 논문지
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• 제1권1호
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• pp.79-88
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• 1999

본 논문에서는 화물운송체계에 GIS/GPS 기반의 AVL을 적용하기 위한 핵심요소기술을 검토하고, 시스템 구성대안을 설정하였다. 또한 시스템 구성대안들을 Life-Cycle Cost 분석을 통하여 평가하였다. 기본가정 및 비용단가에 의한 분석결과 개별차량의 무선통신비용의 부담이 노변통신시설의 유지보수 비용에 비해 전체 LCCE에 큰 영향을 미치는 것으로 나타나 무선통신대안이 상대적으로 고비용의 시스템 구성안인 것으로 분석되었다. 그러나 여러 가지 요인에 따른 민감도 분석결과 노변시설의 설치간격, 무선통신비용단가의 하락 등을 가정할 경우 무선통신대안이 운영측면의 경제성을 갖는 것으로 분석되었다. 무선통신대안과 노변통신대안 모두 각각의 장단점을 갖고 있으므로 지역적 특성 내지는 교통시설의 특성에 따라 혼합적용하는 방안이 검토되어야 한다. 본 연구는 GIS/GPS-AVL의 화물운송체계 적용시 시스템구성요소 및 구축방향을 결정하는데 도움을 줄 것이다.

• Structural Engineering and Mechanics
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• 제36권3호
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• pp.321-341
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• 2010

The seismic-induced failure of a dam could have catastrophic consequences associated with the sudden release of the impounded reservoir. Depending on the severity of the seismic hazard, the characteristics and size of the dam-reservoir system, preventing such a failure scenario could be a problem of critical importance. In many cases, the release of water is controlled through a reinforced-concrete intake tower. This paper describes the application of a static nonlinear procedure known as the Capacity Spectrum Method (CSM) to evaluate the structural integrity of intake towers subject to seismic ground motion. Three variants of the CSM are considered: a multimodal pushover scheme, which uses the idea proposed by Chopra and Goel (2002); an adaptive pushover variant, in which the change in the stiffness of the structure is considered; and a combination of both approaches. The effects caused by the water surrounding the intake tower, as well as any water contained inside the hollow structure, are accounted for by added hydrodynamic masses. A typical structure is used as a case study, and the accuracy of the CSM analyses is assessed with time history analyses performed using commercial and structural analysis programs developed in Matlab.

• 조명전기설비학회논문지
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• 제26권7호
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• pp.99-109
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• 2012

Sub-station, key equipment in electric power infrastructure, are being exposed to increasing risk of hacking. For this, soft redundancy sub-station system needs to be formulated with automatic restoration mechanism. For this it is important to assess the reliability of the applicable range of data that are used in actual system operation, as well as the methods and findings of the tests. At the same time performance of soft redundancy system and total security mechanism, which are aligned for the protection of the sub-station, need to be tested. For testing the above-mentioned, this paper presented a viable formation of a soft redundancy practical VPN system within a panel to protect the latter from hacking or cracking incidences, and conducts a test to check if the considered system actually serves the protection function in the actual operation setting, gathering evidence from the data from the testing of the actual performance of the system as well as of emergency scenario simulation operations. Because tested soft-redundancy & restorative sub-station system is expected to be widely applicable for various cases such as Smart-grid or electricity IT system, where VPN with enhanced level of security is required.

• Journal of Communications and Networks
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• 제18권6호
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• pp.938-947
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• 2016

A mobile ad hoc network (MANET) is a collection of mobile nodes communicating in an infrastructure-less environment without the aid of a central administrating authority. Such networks entail greater dependency on synergy amongst the nodes to execute fundamental network operations. The scarcity of resources makes it economically logical for nodes to misbehave to preserve their resources which makes secure routing difficult to achieve. To ensure secure routing a mechanism is required to discourage misbehavior and maintain the synergy in the network. The proposed scheme employs a partially distributed dynamic model at each node for enhancing the security of the network. Supplementary information regarding misbehavior in the network is partially distributed among the nodes during route establishment which is used as a cautionary measure to ensure secure routing. The proposed scheme contemplates the real world scenario where a node may exhibit different kinds of misbehavior at different times. Thus, it provides a dynamic decision making procedure to deal with nodes exhibiting varying misbehaviors in accordance to their severity. Simulations conducted to evaluate the performance of the model demonstrate its effectiveness in dealing with misbehaving nodes.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권4호
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• pp.1751-1767
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• 2016

Home security has become the prime concern for everyone in present scenario. In this work an attempt has been made to develop a home security system which is accessible, affordable and yet effective.The proposed system is based on 'Remote Embedded Control System' (RECS) which works both on the web and gsm platform for authentication and monitoring. This system is therefore cost effective as it relies on existing network infrastructure. As PCA is most popular and efficient algorithm for face recognition, it has been usedin this work. Next to it an interface has been developed for communication purpose in the embedded security system through the ZigBee module. Based on this embedded system, automated control of door movement has been implemented through electromagnetic door lock technology. This helps the users to monitor the real-time activities through web services/SMS. The web service consists of either web browser command or e-mail provision. The system establishes the communication between the system and authenticated user. The e-mail received by the system from the authorized person will monitor and control the real-time operation and door lock. The entire control system is reinforced using ARM1176JZF-S microcontroller and tested for actual use in the home environment. The result shows the experimental verification of the proposed system.

• 전기학회논문지
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• 제66권7호
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• pp.1007-1016
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• 2017

This paper aims to analyze the safety evaluation of the existing transformer for the 0.85 millions of public rental apartments as EVs(Electric Vehicles) increase in order to overcome the environment pollution issue and maintain sustainable development. It is analyzed that the 56.4% capacity of power transformer could secure as EV charging infrastructure, based on the analysis of respective utilization patterns of the housing and power transformer. The acceptable number of EVs is 0.04~0.06 per household from the spare capacity of the power transformer. It is analyzed that EV stock is prospected less than 0.03 per household in 2030, considering the condition of the public rental apartments residents and the growth rate of EVs according to practical scenario. The power demand for EVs is within the allowable capacity range of the power transformer, so the research shows that there is no problem in the stability of the existing transformer until 2030.