• 전기학회논문지
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• 제65권1호
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• pp.23-30
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• 2016

Wake effects cause wind turbine generators (WTGs) within a wind power plant (WPP) to produce different levels of active power and subsequent reactive power capabilities. Further, the impedance between a WTG and the point of interconnection (POI)-which depends on the distance between them-impacts the WPP's reactive power injection capability at the POI. This paper proposes a voltage control scheme for a WPP based on the available reactive current of the doubly-fed induction generators (DFIGs) and its impacts on the POI to improve the reactive power injection capability of the WPP. In this paper, a design strategy for modifying the gain of DFIG controller is suggested and the comprehensive properties of these control gains are investigated. In the proposed scheme, the WPP controller, which operates in a voltage control mode, sends the command signal to the DFIGs based on the voltage difference at the POI. The DFIG controllers, which operate in a voltage control mode, employ a proportional controller with a limiter. The gain of the proportional controller is adjusted depending on the available reactive current of the DFIG and the series impedance between the DFIG and the POI. The performance of the proposed scheme is validated for various disturbances such as a reactive load connection and grid fault using an EMTP-RV simulator. Simulation results demonstrate that the proposed scheme promptly recovers the POI voltage by injecting more reactive power after a disturbance than the conventional scheme.

• 전자공학회논문지CI
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• 제45권4호
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• pp.41-52
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• 2008

유비쿼터스 서비스 환경에서는 연결의 신뢰성이 낮고 서비스를 제공하는 시스템에 대한 침입이나 서비스 실패가 발생할 확률이 높다. 따라서 유비쿼터스 컴퓨팅 환경에서는 본연의 서비스를 지연 없이 제공할 수 있는 시스템 능력, 즉 서비스 생존성을 제고해야할 필요가 있다. 본 논문에서는 유비쿼터스 정보 서비스 환경에서 결함감내 Jini 서비스 개발을 돕는 Jgroup/ARM 프레임워크를 분석한다. 이 분석을 토대로 보안성과 가용성 서비스 품질을 만족하는 침입감내 Jini 서비스 구조를 제시한다. 제시된 침입감내 Jini 서비스 구조는 네트워크 분할이나 서버 붕괴와 같은 결함뿐만 아니라 취약점을 악용한 공격으로부터 시스템을 보호할 수 있으며 심리스 서비스 지속이 가능하도록 낮은 응답지연의 성능을 보여준다. 테스트베드를 통해 실험한 결과, 서비스 품질 저하를 무시할 수 있는 수준에서 높은 보안성과 가용성을 제공할 수 있음을 확인하였다.

• Applied Microscopy
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• 제25권3호
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• pp.82-89
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• 1995

지금까지의 실험결과에서 다음과 같은 요약할 수 있다. 1) 사원계 $Zn_{1-x}Mg_{x}S_y$ $S_{1-y}$(x=0.13, y=0.16) 에피층은 다소 불규칙한 성장을 나타내어 역삼각형의 결함과 길고 직선인 적층결함으로 형성된 수지상 형태가 발견되었다. 2)역삼각형 결함은 {111}면에 형성된 적층결함으로 둘러싸여 있고 내부에는 결함이 없으나 계면과 수직인 방향인 <001>방향으로 콘트라스트 차이를 이루는 밴드가 형성되었다. 3) 기판과 정합을 이루고 있고 결함이 없는 ZnSe 버퍼 층이 관찰되었으며 결함 및 므와레 줄무늬는 버퍼층과 4원계 에피층과의 계면에서 형성된다. 4) 4원계 에피층에 형성된 적층결함은 Mg 원소의 효과로 길이가 60nm 이상 폭이 40nm 이상의 넓은 간격을 이루고 있다. 5) 긴 적층결함으로 둘러쌓인 수지상 구조에는 국부적으로 주기를 이루며 강한 콘트라스트 차이를 나타내는 줄무늬가 관찰되는데, 이는 Mg 및 S의 국부적인 화학적 조성차이에 기인한 탄성 변형 효과로 생각된다.

• 한방안이비인후피부과학회지
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• 제16권3호
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• pp.164-184
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• 2003

Objectives : This study was designed to establish a characteristic discrimination of internal and external morphological standard of original plants and herbal states in Pogostemonis and Agastachis Herba. Methods : In this studies, the external-internal morphological standards were determined by using stereoscope and butanol series. Results : 1. The external characteristics: Pogostemon cablin has hairs and brown-like in stem, elliptical fruit. On the other hand, Agastache rugosa has no hairs and red-like in stem, obovatic trigone fruit. 2. The physical characteristics: Pogostemon cablin is gray in whole, has hairs in stem and numerous hairs of ash in leaf. On the other hand, Agastache rugosa is yellow-green in whole, has no hairs in stem. Specially the latter has deep-green colour and numerous hairs presenting mostly at lower epidermis in leaf. 3. The physical characteristics in currents: Pogostemon cablin is brown, has hairs and round-like stem. On the other hand, Agastache rugosa is green or yellow-green, has no hairs and tetragon in stem. 4. The internal characteristics: Pogostemon cablin has progressed spongy tissue in epidermal cell of leaf and many rank of epidermal cell in stem. On other hand, Agastache rugosa has I rank palisade tissue in leaf and few rank of epidermal cell in stem. In the external shape, it was possible that herbs were distinguished according to artificial cIassification and that same genus-degree of relatedness among herbs could be distinguished by more precise and active observation. In the shape of real herbs, I compared current herbs in market with original herbs which were just collected or were on the course of drying. In addition, it was possible that the internal shape could be identified by using microscope after butanol series. Conclusion : Though it was impossible to make distinction of herbs which are not current in my search contents, this search contents will be a standard for applying herbs in the future. An Additional standard establishment including physiochemical reaction and gene research is required in order to supplement the fault of this search.

• Earthquakes and Structures
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• 제14권6호
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• pp.615-626
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• 2018

The seismic vulnerability of Turkey is relatively high due to its active fault systems with potential to create destructive earthquakes. Thus, reducing the loss of life and property, the number of the earthquake-prone buildings and their retrofit requirements are considerably significant key issues under the scenario earthquakes. The street survey based rapid assessment (SSRA) method can be considered as a powerful tool to determine the seismic vulnerability of building stock of an earthquake-prone city/state. In this study, the seismic vulnerability of the building stock of the Kirikkale province in Turkey is aimed to be estimated adopting the street survey based rapid assessment method (SSRA). For this purpose, central 2074 existing reinforced concrete (R/C) buildings were structurally surveyed with rapid visual site screening and disadvantages such as, the existence of short-column, soft-story, heavy overhangs, pounding effect and local soil conditions were determined for obtaining the structural performance score of each. The results obtained from the study demonstrate that 11-25% of the surveyed buildings in the study region needs to be investigated through more advanced assessment methods. Besides, higher correlation between increasing story number and unsafe/safe building ratio is obtained for the buildings with soft-story parameter than that for those with heavy overhangs and short-column parameters. The conformity of the results of the current study with the previous documented cases of rapid assessment efforts in the recent earthquakes in Turkey shows that the SSRA method for the Kirikkale province performed well, and thus this methodology can be reliably used for similar settlement areas.

• 한방안이비인후피부과학회지
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• 제13권1호
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• pp.253-266
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• 2000

In order to strengthen objectivity and availability of oriental herb medicine, the standard formula for herbs has been attempted to set up by experimenting and documentary testing original herbs which were recorded in authorized document. The object herb medicine is Codonopsis Pilosulae Radix. The internal and external morphological standard in this study is expected to supply the search for several physiochemical reaction, biological reaction, determination of indicator material and identification of gene with basic sources in the future. The result of study is as follows; In the external shape, it was possible that herbs were distinguished according to artificial classification and that same genus-degree of relatedness among herbs could be distinguished by more precise and active observation. In the shape of real herbs, I compared current herbs in market with original herbs which were just collected or were on the course of drying. In addition, it was possible that the internal shape could be identified by using microscope after butanol series. In powder herbs, it was possible to purify the shape by microscope through maceration of natural and powder herbs. Though it was impossible to make distinction of herbs which are not current in my search contents, this search contents will be a standard for alpplying herbs in the future. Despite such a useful character, it was difficult to deal with power herbs because it was uncertain to make a standard for them on account of the crush of these tissue. Since powders shape of herbs in a few documents were regard not as the powder shapes of natural herbs but as the maceration state of them. It is suggested that we should inspect the original herbs which are not crushed yet with a microscope in order to identify crushed shape of powder herbs from now on. An Additional standard establishment including physiochemical reaction and gene research is required in order to supplement the fault of this search. As for the supplement about this search, considering that many kinds of same genus-degree of relatedness are being current now, it is necessary that each herb should he collected only after identifying and that the succeeding search of each herb should be proceeded for the regular establishment of internal and external standard.

• 정보처리학회논문지D
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• 제11D권2호
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• pp.351-360
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• 2004

대부분의 이동 에이전트는 순차적인 노드 이주 방식에 의하여 다수의 이동 에이전트 시스템들로 이주된다. 하지만, 이러한 이주방식에서는 호스트의 결점이나 장애 등과 같은 문제가 발생하였을 경우, 이동 에이전트가 무한 대기나 고아 상태에 빠지므로 노드들 사이의 네트워크 소요시간이 증가하기 때문에 실제 다른 분산 기술들을 사용한 것만큼의 기대효과를 얻기가 어렵다. 따라서 이러한 문제를 해결하기 위한 연구들이 진행되어 왔지만 대부분 수동적 라우팅 테이블을 기반으로 노드의 이주를 결정하거나 문제가 발생된 호스트를 선회하는 방법이므로 실제 전체적인 네트워크 소요시간을 감소시키기 위한 연구는 아직 미흡하다. 본 논문에서는 이동 에이전트가 이동 에이전트 시스템들로 이주시 네트워크 소요시간을 감소시키기 위하여 네이밍 에이전트의 메타-테이블에 등록된 구현 객체 정보를 기반으로 능동적 라우팅 테이블을 설계한다. 또한 사용자의 키워드에 대하여 메타-테이블에서 일치하는 객체 참조자의 정보와 수에 따라 다수의 에이전트 객체를 복제한다. 복제된 객체는 이동에이전트 시스템들로 병렬 이주되며, 최소의 네트워크 소요시간을 제공한다.

• 한국정보처리학회논문지
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• 제4권11호
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• pp.2832-2839
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• 1997

본 연구에서는 Asynchronous Transfer Mode (ATM) 계층의 기능중 유휴 가상 채널에 프로토콜 프로토콜 적합성 시험 제어 기능을 갖게 하여 Test Coordination Procedures (TCP) 채널로 활용하는 방안을 제시하였다. 프로토콜 적합성 시험을 위하여 국제 기구에서 권고하고 있는 방법중 원격 시험 방법을 선택하면 System Under Test (SUT)측에 서 능동적으로 Test Event를 발생시켜야 하는 경우에 개발자가 직접 수동적으로 운용을 하거나, Implementation Under Test (IUT)에 대한 제어 및 관찰이 불가능한 경우도 발생하게 된다. ATM망에서 프로토콜 적합성 시험시 시험 영역(Test Coverage)을 최대화하고, 오류검출 영역(Fauit Coverase)을 극대화하기 위해서는 원격시험방법보다는 분산시험방법이 적절하며, 분산시험방법을 채택할 경우 TCP를 구현하기 위하여 시험정보를 전달하기 위한 채널을 확보하는 것이 요구된다. 본 고에서 제안하고 있는 방법은 오류 검출 영역을 극대화 시키고 오퍼레이터의 개입없이 시험의 자동화 구현이 용이하고, ATM장치의 정상동작에는 영향을 주지 않음은 물론 시험제어를 위한 별도의 채널을 확보하지 않고서도 분산시험방법을 적용할 수 있다는 점 을 특징으로 들 수 있다．

• 자동차안전학회지
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• 제11권2호
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• pp.6-10
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• 2019

This paper describes effectiveness of accident reduction on vehicles equipped with AEB using accident data occurring in Korea. During the statistical period, we used the number of vehicles which are covered by auto insurance and the number of accidents. To maximize the reduction effect of accidents caused by the driver's carelessness, the analysis was limited to Physical Damage Coverage that covers the cost of repairing or replacing the damaged vehicle caused by the driver's fault. Due to Personal Information Protection Law, it was not capable of comparing the same vehicle using Vehicle Identification Number in this study. Instead of that, we used it as a similar vehicle, so there are limits to the comparison and analysis results. As a result of this study, we have found that the effect of reducing accidents was different depending on the vehicle class, but it was generally concluded that the number of accidents decreased when the vehicle was equipped with an AEB system. Domestic research on the AEB effect of reducing accidents is not active yet. Therefore, it is absolutely essential to analyze the effects according to various conditions such as driver's age, occupation and gender as well as expanding the study models in the future.

• Physical Therapy Rehabilitation Science
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• 제10권1호
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• pp.1-9
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• 2021

Objective: Joint mobilization for arthrokinematics altered by the positional fault of chronic ankle instability (CAI) is an effective intervention for stabilization. In this study, we compared the effects of ankle dorsi flexion range of motion (DFROM) and dynamic balance ability (DBA) in CAI patients via passive joint mobilization (PJM), a method traditionally performed in previous studies, and active joint mobilization (AJM), a method that can have a greater effect on cortical excitability with spontaneous movements. Design: Single-blind two-arm randomized controlled trial Methods: A total of 30 participants were registered: 15 each to the PJM and AJM groups. Each participant received a total of 10 intervention sessions, 10 minutes per session, 5 times a week for 2 weeks. PJM used Maitland's mobilization method to apply joint mobilization with talus in the posterior direction and AJM used an angular joint motion to induce patient's voluntary motion of medial malleolus anterior gliding and lateral malleolus posterior gliding, respectively. DFROM of the ankle was measured by using tape and DBA was evaluated by using the balance system. Results: Significant improvement was observed after intervention in both the PJM and AJM groups except for the DBA-anterior and DBA-right variables of the PJM group. There were statistically significant differences between the AJM and PJM groups in the DFROM, DBA-anterior, DBA-posterior, and DBA-right variables. Conclusions: The overall improvement of DFROM and DBA was found to be more effective in joint mobilization including voluntary movement. When it is accompanied by voluntary movement, it further affects the neuromuscular system of the ankle.