• 제목/요약/키워드: Self Restoration

검색결과 179건 처리시간 0.024초

ATM-VP 전송망에서의 서비스 레벨 분류에 의한 Self-healing 방법 (The Self-healing Method using Services Level in ATM-VP Network)

  • 이동욱;홍충선;이대영
    • 한국정보처리학회논문지
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    • 제7권11호
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    • pp.3500-3508
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    • 2000
  • ATM 네트워크에서 오류가 발생한 VP를 복원하기 위해 많은 자기치료 (Self-healing) 알고리즘이 이미 제안되어 왔다. 알고리즘 중 가장 많이 사용되는 것은 백업 VP를 이용하는 방법이다. 백업 VP를 이용한 알고리즘의 문제점은 백업 VP의 오류가 발생하였을 경우 심각한 문제가 발생하게 되며, 이를 보완하기 2차 백업 VP를 설정하는 알고리즘 제안되었다. 2차 백업 VP를 두는 알고리즘의 경우는 초기 계산량이 너무 많은 단점이 있다. 본 논문에서는 서비스 레벨에 따라 차등의 알고리즘을 두고 3가지 CASE별로 복구알고리즘을 적용하고 또한2차 백업으로 설정 알고리즘의 문제를 해결하여, 상대적으로 고가의 서비스가 되는 실시간 서비스 오류를 방지하는 자기치료 알고리즘을 제안한다. 또한 시뮬레이션을 통해 기존의 알고리즘과 비교하여 성능을 분석하였다.

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자체기동발전원으로서 BESS의 활용가능성 분석 및 용량 산정에 관한 연구 (A Study on the Feasibility Analysis and Capacity Estimation of BESS for Self-Starting Generators)

  • 김차년;유원근;김헌태;이흥재
    • 전기학회논문지
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    • 제67권9호
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    • pp.1119-1124
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    • 2018
  • So far BESS(Battery Energy storage system) has been widely applied to power systems rapidly. Usually it has been used to regulate the renewable energy output and to adjust the power system frequency. In 2013, EPRI has reported a study of utilizing BESS to replace two black start generators of American Electric Power(AEP) that will be demolished. If the BESS can be used as a self-starting generator, it is possible to shorten the long-distance primary transmission line and shorten the restoration time because BESS is capable of the high-speed start and there is no restriction on the installation position. This paper presents a possibility of using BESS as a self-starting generator by using PSCAD/EMTDC in Korean power systems. Herein, the process to estimated the required capacity of BESS is also presented.

비무장지대(DMZ) 인근의 훼손지 유형 분석 및 복원방향 (Analysis on the Type of Damaged Land in DeMilitarized Zone(DMZ) Area and Restoration Direction)

  • 성현찬;김수련;강다인;서정영;이상미
    • 한국환경복원기술학회지
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    • 제19권1호
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    • pp.185-193
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    • 2016
  • Purpose of this study is to classify damaged lands according to the cause of the damage and their influences based on characteristic of the damaged lands in DeMilitarized Zone(DMZ) area, and utilize this study as a fundamental study for establishment of ecosystem restoration system. Literature review and field survey have been conducted to review the damage status of DMZ area. For field survey, first year and second year have been conducted, in which type of the damage has been reviewed in this study. In the result, types of damage have been classified into 6 categories: 'alteration of initial landform', 'loss of surface layer', 'land pollution', 'alteration of soil chemical property', 'decline of vegetation', and 'invasion of foreign species'. Restoration for each damage type is as following. First, for alteration of initial landform, the land is restored to the original landform prior to the damage and connection to surrounding ecosystem is considered. Second, for loss of surface layer, lost surface layer is restored or further loss is prevented with stabilization. Third, for land pollution, source of the pollution is eradicated or self-circulation with purification of polluted land is encouraged. Fourth, for alteration of soil chemical property, soil is restored of its original property with eradication of the pollution source and improvement of soil. Fifth, for decline of vegetation, current vegetation and anticipated alteration in future are considered and number of wild species is to be increased based on structure and characteristic of nearby vegetation. Sixth, for invasion of foreign species, prevention of dominance by risky species and facilitation ecological stability with ecological management are to be considered. Influence according to the cause of damage has occurred in secondary(indirect) influence or simultaneous occurrence of several damage types. Considering all these aspects, when type of the damage is complex, restoration process for each of former mentioned 6 damage types with solitary influence should be considered in unison.

무안 창포호의 자연생태친수공간 조성을 위한 관리방안 기초 연구 (The Management Plan for the Ecological Waterfront Space of Muan Changpo Lake)

  • 서정영
    • 한국환경복원기술학회지
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    • 제22권3호
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    • pp.15-30
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    • 2019
  • Changpo Lake was created as a part of a land reclamation for refugee self-helping projects. It shows characteristics of a fresh water lake, and still retains the early appearance of reclamation that surrounding regions have not been developed into farm lands. Shallow wetland has formed around the lake, which provides great conditions for diverse lives, and surrounding earthiness is favorable for growth of vegetation and restoration of the ecosystem. However, as facilities of the Muan International Airport nearby Changpo Lake are expanding and barns are being constructed, artificialness is gradually increasing. Particularly, since pollution sources such as sport facilities, farm lands and barns are scattered around Changpo Lake, pollutants are flowing in constantly. Accordingly, the results for setting up management areas according to the spatial characteristics and creating natural ecological spaces near Changpo Lake, Taebongcheon stream and Hakgyecheon stream are as follows. First, the creation of a natural eco-friendly waterfront space should be promoted by securing the health of the aquatic ecosystem and restoring species and the ecosystem. In addition, a consultative body needs to be formed to lead local residents to participating in river investigation and monitoring, maintenance, and management through role sharing. Second, the basic direction of the spatial management plan is to keep the unique charm of Changpo Lake, maintain harmony with nature, create diverse waterfront areas, and secure the continuity of Changpo Lake and inflow streams. Moreover, the area should be divided into three zones such as a conservation zone, a restoration zone and a waterfront zone, and for each zone, the preservation of vegetation, the creation of ecological wetlands and restoration of the ecotone and ecological nature need to be promoted. Third, facilities and activity programs for each space of Changpo Lake should be operated for efficient management of protected areas. In order to suit the status of each space, biological habitats, water purification spaces, experiential and learning spaces, and convenience and rest spaces should be organized and designated as research, monitoring, education, and tourism areas. Accordingly, points of interest should be set up within the corresponding area. In this study, there are many parts that need to be supplemented for immediate implementation since the detailed plans and project costs for the promotion of programs by area are not calculated. Therefore, it is necessary to make detailed project plans and consider related projects such as water quality, restoration of habitats, nature learning and observation, and experience of ecological environments based on the categories such as research, monitoring, education and tourism in the future.

돌극형 동기 발전기의 무효전력 공급 한계 해석 및 우선공급계통에의 적용 (Analysis of Reactive Power Capability for Salient Synchronous Generators, and its Application to Primary Restorative Systems)

  • 이흥재;박성민
    • 전기학회논문지
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    • 제56권1호
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    • pp.14-17
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    • 2007
  • Power system restoration following a massive blackout starts with re-energizing primary restorative transmission systems at first. The comparison of the TLCC(transmission line charging capacity) and the RPC(reactive power capability) of related black-start generator should be considered in this stage because overvoltage can be caused by self-excitation at the generator when the RPC is smaller than the TLCC. The RPC can be decided by two criteria. One is stator end core heating, and the other is steady state stability. RPC in steady state stability area has been found based on a synchronous reactance Xd. This paper presents RPC limit of salient pole machine which is different from that of non-salient pole machine in steady state stability area and shows derivation process about that.

전치부 Pontic ridge lap 제작에 대한 연구 (A Study on the Making of Anterior Pontic Ridge Lap)

  • 김욱태
    • 한국콘텐츠학회논문지
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    • 제16권3호
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    • pp.328-334
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    • 2016
  • 본 연구는 보철치료의 최종 목적인 결손치아 및 그 주위 조직의 정상적 기능의 회복과 유지를 위한 전치부 교의치의 반 자정(ridge lap)형 가공치의 체계적인 제작 방법을 연구하였다. 가공치가 갖추어야 할 설계 기준를 제도화 하였고, 치과의사의 소견으로 염증, 치주질환, 음식물 잔류 및 자정작용의 효과가 기존의 제작 방법보다 더 우수한 결과를 얻었다. 본 논문에서 제시하는 가공치 제작방법은 임상에 적용해도 무방하다고 판단된다.

A Simulation Study on Regularization Method for Generating Non-Destructive Depth Profiles from Angle-Resolved XPS Data

  • Ro, Chul-Un
    • 분석과학
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    • 제8권4호
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    • pp.707-714
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    • 1995
  • Two types of regularization method (singular system and HMP approaches) for generating depth-concentration profiles from angle-resolved XPS data were evaluated. Both approaches showed qualitatively similar results although they employed different numerical algorithms. The application of the regularization method to simulated data demonstrates its excellent utility for the complex depth profile system. It includes the stable restoration of the depth-concentration profiles from the data with considerable random error and the self choice of smoothing parameter that is imperative for the successful application of the regularization method. The self choice of smoothing parameter is based on generalized cross-validation method which lets the data themselves choose the optimal value of the parameter.

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전신조정술 중재가 자세조절에 미치는 효과 (The Effects of General Coordinative Manipulation Interventions on the Postural Control)

  • 문상은;김미화;주왕석;이수홍;오창선;최민호;정웅채
    • Journal of Acupuncture Research
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    • 제26권5호
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    • pp.137-149
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    • 2009
  • Objectives : This study was designed to analyze whether General Coordinative Manipulation(GCM) Intervention could have effects on the balanced restoration of asymmetrical posture. Methods : Sixty eight(68) healthy volunteers(1st hypothesis: 46, 2nd hypothesis 22) participated in two GCM interventions, which have been performed 2 times a week for 3 weeks. The Global Postural System(GPS) Unit was used to measure the posture, and measurements were performed before and after the application of each intervention group. A paired t-test and wilcoxon test were used to determine the statistical significance. Results : The outcome of examining the hypothesis is as follows: 1. The 1st hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of upper extremity and the extension type of lower extremity, excluding self-care, shows the efficiency in treatment on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 3 of 4 body types. 2. The 2nd hypothesis: It has been proved that GCM Intervention, which coordinates the flexion type of lower extremity and the extension type of upper extremity, excluding self-care, shows the treatment in efficiency on more than two aspects of 3 parts: anterior, posterior and lateral postures, and the effects on more than 2 of 3 body types. Conclusions : GCM intervention programs on the two hypothesis groups have an affect on the balanced restoration of the postural control system.

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수초·골재 하수처리장의 투수속도 (The Infiltration Velocity of a Sewage Disposal System with Water Plant and Gravel Bed)

  • 정동양
    • 한국환경복원기술학회지
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    • 제6권3호
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    • pp.29-34
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    • 2003
  • This paper describes the effects of sewage amount, temperature, and years in operation on the infiltration rate of a sewage disposal system. The self-purifying sewage disposal system, which is typically used in rural areas, consists of reeds and fine gravel. Water plants are planted on the gravel bed which provides the habitat for microbes. The basic process is that the gravel bed filters incoming sewage. Thus this system requires the smooth flow of sewage through the gravel. However, the efficiency of the disposal system will be lowered if the gravel bed is clogged with sewage sludge. A three year study shows that infiltration rate slows down significantly until the 7th day, depending on the sewage amount and the temperature. After the 7th day, the infiltration rate remains almost constant. In addition, the infiltration rate decreases as the temperature falls. It also decreases as the number of years in operation increase. But there is no significant change in the infiltration rate after the 7th day, independent of the temperature, the sewage amount, and years in operation. In order to take advantage of high infiltration rate, which improves the efficiency of the disposal system in its early stages, having two gravel beds and using them alternatively will be efficient. This operation method is called intermittent load and makes the disposal system last longer. The water plant roots above the gravel bed make the effective filtration possible because they delay accumulation of the sewage sludge and stabilize the filtration ability.

유휴농지 농업적 활용 평가지표 설정 및 현장적용 (Establishing Evaluation Indicator for Agricultural Utilization of Idle Farmlands and Field Application)

  • 김경찬;박창원;조석호;최진규;윤성수;손용훈
    • 농촌계획
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    • 제20권2호
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    • pp.127-137
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    • 2014
  • Self-sufficiency rate of food in South Korea is almost at the lowest level among OECD countries, and the decrease tend of farmland is expected to be continued. In this situation, the government has been revised the target self-sufficiency rate of food, and carried forward various policies in order to achieve it. One of those policies is the restoration business of idle farmland which is planned to carry forward after 2015. This study set up indicators evaluating effective use of idle farmland, and tried to apply in the field before carrying forward restoration business. The result of this study may be summarized as follows. First of all, it reset an evaluation indicator that was based on the evaluation indicator developed in order to set application directions of idle farmland. Next, it selected 30 idle farmlands with reset evaluation indicator among 11,635 which were inspected nationwide in 2012. Before applying indicator, it measured the condition of recycling such as accessibility of farmland, condition of irrigation and drainage system, land state, and surroundings by field investigation. Then, it calculated composite score in each target area through applying indicators, and verified the indicator by comparing calculated result with the one which was decided from field investigation. Finally, it carried out field investigation, correct and upgrade some problems of the standard of score calculation that was found during applying previously set evaluation indicator to target area, and established the final standard of calculation for evaluation indicator.