• International Journal of Safety
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• 제5권1호
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• pp.1-4
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• 2006

The safety performance of the current collection system is evaluated by conducting a test run in which accelerometer and load cell signals are analyzed. It has been found that the current collection performance is strongly influenced by the train speed, with the major frequency components arising from the train traversing the span spacing and the 8.5 Hz component originating from the panhead resonance. The train acceleration is found to have significant influence on the span passing frequency but negligible effect on the resonant response.

• 전기학회논문지
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• 제62권4호
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• pp.573-576
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• 2013

In this paper, analysis method for current collection performance based on real-time current of catenary system is proposed. An innovative method based on track-side of railway system is used for measurement of currents for overhead contact line during the collection with pantograph. The evaluation of a qualitative ratio for current collection performance were conducted using proposed algorithm under various conditions such as laboratory and track-side. To check the validity of our approach, we compared between calculation results from current of contact wire and measurement results from arcing of pantograph using simulator in laboratory conditions. The results show that the behavior of current collection performance were analysis from currents of overhead contact line in AC electric railway system.

• 방사선산업학회지
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• 제9권3호
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• pp.161-166
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• 2015

RI-Biomics is the new radiation fusion technology of which, such as the characteristics of radioisotope, is applied to the biomics. In order to sharing and overall analysis of data between the institutions through total management of information in the field of RI-Biomics, RI-Biomics Information portal 'RIBio-Info' was constructed by KARA (Korean Association for Radiation Application) in February 2015. For systematic operation of this 'RIBio-Info' system, it is required to develop system of collection-analysis-application of information. So, in this paper, we summarized development of document forms at each processes of collection-analysis-application of information and systematization of collection methods of information, establishment of characteristically analysis methods of reports such as issue paper, policy report, global market report and watch report. Therefore, these are expected to improving the practical applicability in this field through the vitalization of technology development of users by achieving the circular structure of collectionanalysis-application of information.

• 한국정보과학회논문지:시스템및이론
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• 제31권3_4호
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• pp.204-212
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• 2004

분산 시스템에서는 단일 시스템보다 높은 결함 발생 확률을 가지기에 기존의 맡은 연구에서는 분산 시스템에서 결함 발생에 대한 맡은 결함 포용 기법들이 연구되어 왔다. 하지만 저장된 결함 포용 정보의 증가에 따른 저장 공간의 부족으로 인해 전체 시스템 성능의 저하를 가져오게 하였다. 시스템 성능의 저하를 막기 위하여 불필요한 결함 포용 정보의 삭제가 필요하게 되었고 이 논문에서는 결함 포용 정보의 쓰레기 처리를 위한 방법을 제안한다. 이에 본 논문에서는 결함 포용 정보의 쓰레기 처리를 담당하는 쓰레기 처리 에이전트, 결함 포용 정보를 유지 관리하는 정보 에이전트, 그리고 전체 에이전트간의 통신 기능을 담당하는 조정 에이전트를 정의 및 설계하고, 쓰레기 처리 에이전트를 이용한 쓰레기 처리 알고리즘을 제안한다. 복귀회복 기법은 독립 검사점(independent checkpoint)기법과 송신자 기반 비관적 매시지 로깅(sender based pessimistic message logging)기법을 사용한다. 제안된 쓰레기 처리 기법에서의 쓰레기 처리, 정보, 조정 에이전트는 프로세스와 동시에 생성되며 정보 에이전트에 프로세스에서 발생하는 검사점과 비결정적인 사건들에 대한 로깅 정보들을 영역 지식으로 구축한다. 그리고 쓰레기 처리 에이전트는 쓰레기 처리 시점을 선정하고 정보 에이전트와 조정에이전트의 협력을 통하여 영역 지식에 구축된 불필요한 결함 포용 정보의 쓰레기 처리를 한다. 제안한 에이전트를 이용한 쓰레기 처리기법의 타당성 증명을 위하여 결함을 발생시켜 복귀 회복 후 쓰레기 처리를 하는 시스템과 하지 않는 시스템의 영역지식을 비교하여 같은 결과를 같는지의 여부를 검사한다

• 한국철도학회논문집
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• 제5권1호
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• pp.10-17
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• 2002

In this study, we have developed the static and dynamic simulation program of a high speed current collection system. The catenary wire is modeled to discrete masses connected by massless strings and the pantograph is replaced with 3 d.o.f equivalent models that are composed of masses, springs and dampers. We derived partial differential equations of motion from the equivalent model and developed the simulation program. Then, we calculated the static equilibrium state of the overhead catenary and the dynamic behaviors of the high speed current collection system. The analysis results were compared with the results of GASENDO software developed at RTRI in Japan.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1995년도 추계학술대회논문집; 한국종합전시장, 24 Nov. 1995
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• pp.142-147
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• 1995

Dynamic characteristics of current collection system is one of the major factors which decide the performance of high speed train. To find good design parameters of the current collection system design guide is prepared through the engineering analysis in this study. The analysis starts from the statics of catenary system which results in the sinusoidal variation of stiffness, which is inherently nonlinear Mathieu equation. Simple physical models of rigid trolley wire and Mathieu equation are considered. To simulate the dynamic response of current collection system, numerical integration based on central difference method and modal analysis are presented. The calculated results of central difference method show superior to those of Euler based algorithm.

• International Journal of Safety
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• 제5권2호
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• pp.1-5
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• 2006

A data acquisition and processing system for measuring the current collection signals of the Korean High-speed Railway is developed. The current collection system is composed of a pantograph and the overhead catenary that supplies electrical power to the train through the pantograph. The system simultaneously measures the signals generated at the interface between the catenary and the pantograph through the accelerometers, load cells and strain gauges placed at various locations. The on-track test data are processed to evaluate the current collection reliability. The fiequency analysis of the signals reveals the presence of several structural vibration modes in the pantograph, as well as the components arising from the periodicity in the structure of the catenary and pantograph at the interface. The feasibility of predicting the contact performance from the measured signals is also demonstrated.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.343-345
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• 2003

This paper describes the system development for the Ground Control Point collection and management through the major coastline region in KOREA, which will collect and manage the ground control point based on high resolution satellite image database. The module of this system is following 1) GCP/Coarstline research plan module 2) GCP/Coarstline ground collection module 3) GCP/Coarstline post processing module Our team developed the core components of ‘High Resolution Satellite Image Processing Technique’ project, and this system, among applications of our project, is constructed to apply to practical use. In this application, you will also see how to apply core components of our project.

• Nuclear Engineering and Technology
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• 제56권7호
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• pp.2534-2544
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• 2024

This paper proposes a flooding safety system (FSS) and its operation strategy that can provide long-term safety and effective maintenance for modules of small modular reactor (SMR) and metal containment maintained at dried environment during normal operation. During hypothesized accidents, the FSS re-collects the evaporated steam into the common pool by the condenser installed above the common water pool and provides an emergency coolant for the cavities and auxiliary pools. This study suggested that the condensate re-collection strategy using the FSS can effectively delay the depletion of available water in response to the accidents. Without recollection, the achievable grace periods ranged from 44 to 1507 days for six-module and one-module accidents, respectively. However, with a full re-collection (ratio = 1.0), the time to total depletion of emergency coolant was estimated indefinite. Even with a partial re-collection ratio of 0.3, a grace period of 83.5 days could be ensured for a six-module transient. This study reported the effectiveness of condensate re-collection and the FSS as an innovative safety management strategy and system. Employing a condensate re-collection strategy with a high re-collection ratio can enhance the long-term safety and effective convenience of SMR operations and maintenance.

• 한국입자에어로졸학회지
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• 제17권2호
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• pp.21-27
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• 2021

We developed non-metallic electrodes that can replace metallic electrodes of the electrostatic precipitator(ESP) for the purpose of light weight, corrosion resistance, cost reduction. We manufactured three types of collection electrodes made of stainless steel (M), Carbon ink coating layer-Plastic sheet-Carbon ink coating layer (CPC), and Plastic sheet-Carbon ink coating layer-Plastic sheet (PCP). We studied the collection efficiency of a two-stage ESP using oil mist particles with and without collection stage by changing the flow rate, the material of collection electrode, and the applied voltage of the pre-charger module and the collection module. Here we measured concentrations of particles at diameters of 0.45 ㎛ (CMD; count median diameter) and 3.0 ㎛ (MMD : mass median diameter), as well as PM_2.5 and PM₁₀. As a result of the experiment, two-stage ESP had 22~25% higher collection efficiency in PM_2.5 than one-stage ESP at the same applied voltage. The difference in collection efficiency by varying the materials of collection electrodes was less than 5%. The weight of the non-metallic electrode was only one eighth the weight of the metal electrode. CPC electrode had a thickness of 0.27 mm, which was 1.5 times thinner than a thickness of PCP electrode, so when the flow rate increased, the CPC electrodes couldn't be kept at equal intervals due to the fluttering unlike PCP electrodes. In addition, the PCP-CPC collection module of the present experiment followed the theoretical efficiency based on Deutsch equation and Cochet's charging theory.