• 한국방재학회 논문집
• /
• 제8권4호
• /
• pp.31-38
• /
• 2008

본 연구는 어린이 교통사고의 심각성과 현재 활발하게 추진되고 있는 어린이보호구역의 가변속도표출기(drive feedback sign, 이하 DFS) 설치 및 운영을 배경으로 부천시 어린이보호구역의 DFS 사전 사후 속도조사를 통해 평균속도감속이 교통사고 감소율에 미치는 영향을 조사하여 부천시의 각 초등학교 대상지별 평균속도감소에 따른 교통사고 감소율을 예측한다. 그리고 조사 결과를 바탕으로 부천시 어린이보호구역 지정 초등학교의 DFS운영에 따른 교통사고로 인한 인적재난 감소효과를 알아보는데 그 목적이 있다.

• 한국환경복원기술학회지
• /
• 제22권2호
• /
• pp.59-71
• /
• 2019

This study was conducted to prioritize land purchase in Hwapocheon wetland protection area by reflecting the conservation value of wetlands considering HSI(Habitat Suitability Index) for flagship species. As a result of this study, the flagship species, Oriental White Stork and Been Goose, which can represent the Hwapocheon wetland protection area, were selected through selection criteria and expert feedback. Based on the habitat requirements of the selected flagship species, SI(Suitability Index) for the flagship species was reviewed and the conservation value of wetlands was assessed. The conservation value of the wetlands was divided into five grades from very high to very low. The areas with high conservation value were mainly distributed around wetlands and waters in upstream and downstream of Hwapocheon wetland protection area. The land purchase priorities were divided into five grades by overlapping the thematic maps of the conservation value of wetlands, the economics, and the urgency of restoration. The arable lands which can disrupt wetland ecosystems are analyzed as priority areas where priority purchasing is required. Relatively well-preserved wetlands and areas have low land purchase priorities. This study is meaningful in that biodiversity is considered in land purchase priorities.

• 제어로봇시스템학회논문지
• /
• 제22권7호
• /
• pp.491-495
• /
• 2016

We deal with the regulation problem of nonlinear systems with time-varying delays in both the states and input. A new state feedback controller with dynamic gains is developed based on matrix inequality and non-predictor methods. The proposed control scheme is analyzed using the Razumikhin theorem, and its effectiveness is demonstrated with simulation results.

• Nuclear Engineering and Technology
• /
• 제44권7호
• /
• pp.825-830
• /
• 2012

Radiation and its various industrial applications have been growing at approximately 10 percent per year for the past decade in Korea. As a result, the importance of the Education and Training (E&T) in radiation protection is of upmost importance. This paper is intended to investigate the present status of the E&T on radiation protection and safety in Korea and to draw up the improvements of the E&T courses required for building the national radiation safety infrastructure. For these purposes, the E&T data from the six major domestic organizations providing radiation protection training courses were investigated and analyzed. Each of the organizations is offering several kinds of E&T courses based on their own specific functions. These organizations have administrative facilities equipped with the latest technology for E&T in radiation protection. The E&T courses mainly cover the training courses for radiation workers, radiological emergency staff, license applicants, license holders, and regulatory staff. In 2010, a total of 58 E&T courses were carried out across six organizations. The conclusions make a number of observations highlighting challenges such as: establishing a formal feedback mechanism, introducing more practical training sessions, developing training courses tailored to the job categories and target audiences, and designing education and training courses in radiation protection that comply with current obligations as well as future requirements.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.144-146
• /
• 2007

High frequency voltage signal injection have been widely used but they have some problems like over current protection. High frequency current signal injection and feedback control are more stable than voltage signal injection. In this paper, high frequency current controller for self-sensing and parameter estimation of induction motors is presented.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.140-142
• /
• 2004

본 논문에서는 UC3879 PWM 제어기를 사용한 풀브릿지 위상천이 컨버터의 출력전압 피드백 신호선의 개방과 과전압이 발생하였을 경우에 컨버터를 안정적으로 유지시키기 위한 보호 회로를 제안하고 있다.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2010년도 춘계학술대회 논문집
• /
• pp.1885-1891
• /
• 2010

Recently metropolitan local governments is actively introducing urban railway's expand and light rail transit as a means of new transport system. DC electricity feeder system operating in the domestic urban railway is typically a feedback circuit consisted of the contact wire and electric railway vehicle via rail. But stray current is to be defined as a current flowing on a structure that is not part of the intended electrical circuit with respect to a given structure. Stray current is generally results from the leakage of return currents from large DC traction systems that are grounded or have a bad earth-insulated return path. At the place where the current leaves the rail and metallic structures, electrolytic corrosion may take place. This paper presents comparison analysis of field test methods based on criteria of electrolytic corrosion protection of buried metallic structures adjacent to DC traction systems.

• 한국항공우주학회지
• /
• 제38권3호
• /
• pp.228-235
• /
• 2010

본 논문에서는 틸트로터 항공기의 회전익 모드에 대한 자율비행 유도제어 알고리즘을 적응제어기법을 이용하여 설계하는 것이다. 이를 위해 우선 출력기반 근사적 궤환선형화 기법을 통하여 알고리즘의 내부루프를 구성하고 그로부터 발생하는 모델오차를 단일 은닉층-신경망을 적용하여 상쇄하였다. 그리고 리아푸노프 안정성 이론에 따른 적응제어 갱신법칙은 선형 관측기를 기반으로 설계하였다. 나아가 외부루프는 경로점 유도법칙으로부터 생성되는 궤적을 추종하도록 하였으며 특히 엄밀한 자동착륙 궤적추종 성능 향상을 위하여 방향각 및 비행경로각 시선유도법칙을 설계하였다. 틸트로터 비선형 모델 시뮬레이션 결과는 콜렉티브 입력에서 보이는 순간적인 작동기 포화현상 이외에는 만족할 만한 안정성과 추종성능을 보여 주고 있다.

• Journal of Radiation Protection and Research
• /
• 제41권2호
• /
• pp.117-121
• /
• 2016

Background: Definition and grouping of initiating events (IEs) are important basics for probabilistic safety assessment (PSA). An IE in a spent fuel reprocessing plant (SFRP) is an event that probably leads to the release of dangerous material to jeopardize workers, public and environment. The main difference between SFRPs and nuclear power plants (NPPs) is that hazard materials spread diffusely in a SFRP and radioactive material is just one kind of hazard material. Materials and Methods: Since the research on IEs for NPPs is in-depth around the world, there are several general methods to identify IEs: reference of lists in existence, review of experience feedback, qualitative analysis method, and deductive analysis method. While failure mode and effect analysis (FMEA) is an important qualitative analysis method, master logic diagram (MLD) method is the deductive analysis method. IE identification in SFRPs should be consulted with the experience of NPPs, however the differences between SFRPs and NPPs should be considered seriously. Results and Discussion: The plutonium uranium reduction extraction (Purex) process is adopted by the technics in a model reprocessing plant. The first extraction cycle (FEC) is the pivotal process in the Purex process. Whether the FEC can function safely and steadily would directly influence the production process of the whole plant-production quality. Important facilities of the FEC are installed in the equipment cells (ECs). In this work, IEs in the FEC process were identified and categorized by FMEA and MLD two methods, based on the fact that ECs are containments in the plant. Conclusion: The results show that only two ECs in the FEC do not need to be concerned particularly with safety problems, and criticality, fire and red oil explosion are IEs which should be emphatically analyzed. The results are accordant with the references.

• 한국시스템다이내믹스연구
• /
• 제15권3호
• /
• pp.81-104
• /
• 2014

This study aimed to suggest the directions for the landscape protection of Sindu-ri coastal dune based on its ecological system. The study investigated ecological systems of the coastal dune followed by damage causes of coastal dune according to the land use change, and landscape value of coastal dune in the study area. In order to construct causal-effect feedback loop, systems thinking was performed. Result of this study showed that the area of coastal dune and the amount of sand are maintained by the interaction with sand beach while they are affected by wind direction, wind speed, and dune plants. It was also found that the changes of land use pattern, increasing commercial area, and planted windbreak forest damaged to the coastal dune. In addition, size of coastal dune and growing number of dune plants increased landscape value of coastal dune and tourist draw. However increasing tourists have constantly affected land use changes and have damaged to coastal dune area. In sum, planning for land use regulation, rest-year system areas, promotion and education for coastal dune, dune plants protection, and windbreak management should be taken into account for landscape protection in coastal dune.