• 제목/요약/키워드: recovery cost

검색결과 608건 처리시간 0.027초

가상머신을 이용한 DoS 공격에 강건한 웹 서버 시스템 (Robust Web Server System Using Virtual Machine Against DOS Attack)

  • 박승규;양환석;김배현
    • 디지털산업정보학회논문지
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    • 제9권1호
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    • pp.1-7
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    • 2013
  • The cloud computing is technology which gives flexible and solid infrastructure to IT environment. With this technology multiple computing environment can be consolidated in to a single server so that maximize system resource utilization. Better processing power can be achieved with less system resource. IT manager can cope with increasing unnecessary cost for additional server and management cost as well. This means a enterprise is able to provide services with better quality and create new services with surplus resource. The time required for recovery from system failure will be reduced from days to minutes. Enhanced availability and continuity of enterprise business minimize the codt and the risk produced by service discontinuity. In this paper, we propose framework architecture that is strong against denial-of-service attack.

Lossless Snubber with Minimum Voltage Stress for Continuous Current Mode Tapped-Inductor Boost Converters for High Step-up Applications

  • Kang, Jeong-Il;Han, Sang-Kyoo;Han, Jonghee
    • Journal of Power Electronics
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    • 제14권4호
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    • pp.621-631
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    • 2014
  • To invigorate the tapped-inductor boost (TIB) topology in emerging high step-up applications for off-grid products, a lossless snubber consisting of two capacitors and three diodes is proposed. Since the switch voltage stress is minimized in the proposed circuit, it is allowed to use a device with a lower cost, higher efficiency, and higher availability. Moreover, since the leakage inductance is fully utilized, no effort to minimize it is required. This allows for a highly productive and cost-effective design of the tapped-inductor. The proposed circuit also shows a high step-up ratio and provides relaxation of the switching loss and diode reverse-recovery. In this paper, the operation is analyzed in detail, the steady-state equation is derived, and the design considerations are discussed. Some experimental results are provided to confirm the validity of the proposed circuit.

도시정비형 재개발사업에서 공공참여에 의한 관리처분 및 원가정산 혼용 시행방식에 관한 고찰 (A Study on the Mixed Implementation Method of Management Disposition and Cost Settlement by Public Participation in Urban Renewal Type Redevelopment Projects)

  • 문명렬;전상훈
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2021년도 가을 학술논문 발표대회
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    • pp.254-255
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    • 2021
  • The urban renewal type redevelopment project is a project to improve the urban environment for the recovery of urban functions and revitalization of commercial districts in commercial and industrial areas. Urban regeneration projects are not progressing smoothly. The urban renewal type is not so for landowners, who require a high level of professional knowledge and experience to carry out smooth projects. In addition, the core part of business conflicts can be seen as the problem of management and disposal methods. Therefore, as landowners, etc. become the actual subjects, the public will take charge of project execution, but all development gains and losses will be attributed to the owner of the land, etc.

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대형 가솔린 엔진의 폐열 회수 장치인 슈퍼히터의 최적 위치선정을 위한 시뮬레이션 연구 (A Simulation Study for Selecting Optimum Position of a Superheater in a Waste Heat Recovery System Integrated with a Large Gasoline Engine)

  • 김세린;최경욱;이기형;김기범
    • 대한기계학회논문집B
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    • 제40권2호
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    • pp.69-73
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    • 2016
  • 최근 자동차 엔지니어들은 자동차 엔진의 열효율을 향상시키기 위한 수단으로 폐열 회수 기술에 많은 관심을 기울이고 있다. 배기량이 큰 가솔린 엔진은 대체로 V형인데, 열 회수를 위해 두 개의 슈퍼히터를 각각의 배기 다기관 가까이에 설치하는 것은 비용 면에서 효율적이지 않다. 하나의 슈퍼히터를 한쪽 배기 다기관에 최대한 가깝게 부착하면 좀 더 높은 열교환 효율을 얻을 수 있으나 폐열회수를 위한 배기가스의 유량은 절반이 된다. 반면에, 배기가스의 유량을 전부 이용하기 위하여 두 배기관이 합류된 지점에 슈퍼히터를 설치하면 배기가스의 온도는 많이 감소된다. 이 사실을 바탕으로 슈퍼히터의 최적 위치를 조사하기 위하여 상용프로그램인 AMESim을 이용해 해석을 수행하였다. 이 때, 배기가스 유량 중 절반만을 사용하더라도 슈퍼히터를 배기 다기관과 최대한 가까이 부착하는 것이 엔진의 배기가스로부터 3.8 kW의 열을 더 회수할 수 있는 것으로 나타났다. 이 결과를 바탕으로 최적의 폐열 회수 모델을 도출하고 제안하였다.

비용편익 분석을 통한 소하천유역의 저류조 설치 타당성 분석연구 (Using Cost-Benefit Analysis for a Feasibility Study on Constructing a Storage Facility in the Small River Basin)

  • 서세덕;이승욱;박형근
    • 대한토목학회논문집
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    • 제36권1호
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    • pp.135-141
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    • 2016
  • 본 연구의 목적은 소하천유역의 홍수와 가뭄 예방을 목적으로 설치하는 저류조에 대하여 비용 편익분석을 통해 경제적 타당성을 분석하는데 있다. 소하천유역의 홍수예방이 가능한 저류조 용량에 따른 설치비용을 도출하고, 저류조 설치를 통해 도출될 수 있는 편익요소인 피해금액 및 복구금액, 가뭄예방으로 인한 요소별 편익비용을 적용하여 비용 편익분석을 실시하였다. 이는 홍수와 가뭄을 동시에 예방할 수 있는 다목적 저류조 설치의 타당성을 제시하는 기초자료로 활용할 수 있으며, 세부 연구결과로 자연재해의 피해금액 예측 등 다방면으로 활용할 수 있을 것으로 기대된다.

지속적 어업을 위한 적정 자원이용료 부과에 관한 연구 (Charging Korean Off-Shore Fisheries for Sustainable Fishing)

  • 박성쾌;김기수;김은채
    • 수산경영론집
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    • 제33권2호
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    • pp.49-74
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    • 2002
  • This study examines, from an economic perspective, the reasons for introducing a resource taxe system into the Korean off-shore fisheries and the type of charges that can be introduced. Following a review of the charging systems in other advanced fisheries, we consider the types of charging scheme and some implications for the Korean off-shore fishing industry. Charges could be used for recovering part of fisheries management cost from the industry(i.e. administration, enforcement, research, etc). This can be justified on the grounds that the fishing industry is the main beneficiary of management and that it should therefore bear at least part of the cost involved. It is arguable that publicly-funded management is in effect a subsidy to the industry. Using charges to raise revenue in excess of the cost of management would represent the extraction of a public rent from the fishery resource, but the short-run financial consqquences for the industry would be significant. Results from a qualtitative analysis suggest that while any new charge will have a significant financial impact on the industry in the short run, a landings tax would have a lesser impact on fleet structure in the long run. The study also considers the possibility of a capital gains tax on license sales in order to recover some rent from the industry. Despite any short run-financial consequences, making the fishing industry pay for at least some of the cost of management could benefit the industry as a whole if there were more cooperation between industry and managers as a result. It is acknowledged, however, that there could be disputes over the relative management costs of different sectors of the industry. Even though this study makes few specific recommendations about charging the Korean off-shore fishing industry, it does advise that the issue be reviewed on the basis of the entire Korea fisheries. Finally, the study notes that insufficient data are available on the economic performance of the Korean off-shore fishing vessels and it recommands that a comprehensive system for the collection of costs and earnings data be put in place. It also suggests that MOMAF pay much attention to the permit right market and its transactions.

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공공부문 정보시스템 통합의 경제적 성과 측정 사례연구 (A Case Study of the Economic Performance Measurement of Information System Integration in Public Sector)

  • 정해용;나종회
    • 디지털융복합연구
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    • 제8권4호
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    • pp.185-204
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    • 2010
  • 본 연구는 정부기관의 정보시스템을 통합한 정부통합전산센터의 사례를 중심으로 IT 통합의 경제적 성과를 측정하였다. 성과측정을 위해 측정항목은 TCO 비용항목에 기반하여 사전 2개 기관에 대한 시범분석을 통하여 최종 측정항목을 개발하였다. 측정결과, IT 자산비용이 가장 큰 경제적 성과로 성과의 대부분을 차지하고 있으며, 다음으로 IT 지원비용과 IT 관리비용의 순으로 경제적 성과가 있는 것으로 조사 및 분석되었다. 본 연구의 주요 의의로는 국내외 선행연구 검토를 토대로 TCO 방법론에 따라 2개 기관을 대상으로 시범분석 과정을 통하여 TCO 측정항목을 IT 통합성과 측정에 적합하도록 개발하였으며, 동 측정항목을 기준으로 신뢰성 있는 현황자료를 토대로 객관적으로 경제적 성과를 측정하였다는 점이다.

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The Effect of Export on R&D Cost Behavior: Evidence from Korea

  • Chang Youl Ko;Hoon Jung
    • Journal of Korea Trade
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    • 제26권5호
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    • pp.23-38
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    • 2022
  • Purpose - This research intends to find out whether R&D cost stickiness shows differentiated aspects depending on exports in Korea. A cost behavior that indicates a lower rate of costs decrease when sales decrease than the rate of costs increase when sales increase is called cost stickiness. This sticky cost behavior is caused by considering the adjusting costs. This study aims to empirically verify that R&D cost stickiness is greater in export firms than in non-export firms. We also investigate the effect of exports on R&D cost stickiness is nonlinear. Design/methodology - We obtain data for the analysis from Kis-Value and TS2000 from 2012 to 2020. This study tests for R&D cost stickiness of exports using the cost stickiness model developed by Anderson et al. (2003) that is used in a lot of prior literature. To explore the nonlinear behavior of R&D cost stickiness we include a quadratic term of exports in our model. Findings - The results of our analysis are as follows. First, we observed that R&D costs of export firms are more sticky than that of non-export firms. Our result indicated that export firms are less likely to reduce R&D costs in decreasing sales periods in preparation for future sales recovery. Second, our empirical evidence shows that export firms view R&D costs much favorably. However, we hypothesize that the effect of export intensity on R&D costs may not necessarily be linear. Our result shows the effect of exports intensity on R&D stickiness is thus nonlinear, forming a reverse U-shaped curve. When export intensity exceeds a certain threshold, the growth rate of R&D costs appears to be viewed negatively. Firms with relatively high export intensity do not support R&D costs, viewing them as taking away firms' resources from other more productive costs. On the contrary, those with export intensity under the threshold view R&D costs as beneficial and therefore promote further R&D costs when revenue decreases. Originality/value - The results of this research can contribute academically to the expansion of empirical research on R&D cost stickiness. R&D cost stickiness varies by industry. As a result of our research, the managers of export firms recognize the importance of R&D to lead innovation. We expected that this research contributes to further studies on R&D costs and cost stickiness. Second, this research has implications from a business perspectives. Our findings of export firms' R&D stickiness suggest that export firms' managers should consider keeping the stickiness of R&D when revenue decreases because it is essential for exporting firms to maintain their R&D stickiness to secure long-term competitiveness. R&D stickiness can be used on a practical basis to emphasize the need for continuous investment in exporting firms' R&D activities.

A techno-economic analysis of partial repowering of a 210 MW coal fired power plant

  • Samanta, Samiran;Ghosh, Sudip
    • Advances in Energy Research
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    • 제3권3호
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    • pp.167-179
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    • 2015
  • This paper presents a techno-economic analysis of a partial repowering scheme for an existing 210 MW coal fired power plant by integrating a gas turbine and by employing waste heat recovery. In this repowering scheme, one of the four operating coal mills is taken out and a new natural gas fired gas turbine (GT) block is considered to be integrated, whose exhaust is fed to the furnace of the existing boiler. Feedwater heating is proposed through the utilization of waste heat of the boiler exhaust gas. From the thermodynamic analysis it is seen that the proposed repowering scheme helps to increase the plant capacity by about 28% and the overall efficiency by 27%. It also results in 21% reduction in the plant heat rate and 29% reduction in the specific $CO_2$ emissions. The economic analysis reveals that the partial repowering scheme is cost effective resulting in a reduction of the unit cost of electricity (UCOE) by 8.4%. The economic analysis further shows that the UCOE of the repowered plant is lower than that of a new green-field power plant of similar capacity.

건물 에너지 상세 해석을 통한 소형 열병합 발전 및 히트펌프 복합 시스템의 경제성 분석 (Energy and Economic Analysis of Heat Recovery Cogeneration Loop Integrated with Heat Pump System by Detailed Building Energy Simulation)

  • 서동현;고재윤;박률
    • 설비공학논문집
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    • 제21권2호
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    • pp.71-78
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    • 2009
  • Up until recently, the energy and the economic analysis of a cogeneration system have been implemented by a manual calculation that is based on monthly thermal loads of buildings. In this study, a cogeneration system modeling validation with a detail building energy simulation, eQUEST, for a building energy and cost prediction has been implemented. By analyzing the hourly building electricity and thermal loads, it enables users to decide proper cogeneration system capacity and to estimate more accurate building energy consumption. eQUEST also verified the energy analysis when the heat pump system is integrated with the cogeneration system. The mechanical system configuration benefits from the high efficiency heat pump system while avoiding the building electricity demand increase. Economic analysis such as LCC (Life Cycle Cost) method is carried out to verify economical benefits of the system by applying actual utility rates of KEPCO(Korea Electricity Power COmpany) and KOGAS(KOrea GAS company).