• 한국철도학회논문집
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• 제3권3호
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• pp.147-153
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• 2000

The train control and monitoring system (TCMS) is an on board computer system in railway vehicles performing the control, supervisory and diagnostic functions of the complete train system. This system replaces a lot of hard-wired relays and minimizes the necessary vehicle wiring thus increasing the reliability of the train. It is also one of more important equipment on vehicle to implement much higher safety and reliability train system. We studied a software design technique of TCMS using a CASE tool that is a kind of safety critical software engineering tool (SCADE). This tool has mainly four functions such as the graphical editor, the document maker, tile automatically code generator, and the test simulator. The several functions of TCMS are implemented in this software easily programmed using a functional block diagram and a graphic programming language. We applied to automatically generated TCMS modules on the SCADE each functional block for the Standard type EMU in Korea. We performed the combination test using TCMS simulator and the running test in Seoul subway 7 Line. We proved that this technique is more useful for the software design of TCMS in urban transit

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.896-908
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• 2022

As a part of probabilistic risk (or safety) assessment (PRA or PSA) of nuclear power plants (NPPs), the primary role of human reliability analysis (HRA) is to provide credible estimations of the human error probabilities (HEPs) of safety-critical tasks. In this regard, it is vital to provide credible HEPs based on firm technical underpinnings including (but not limited to): (1) how to collect HRA data from available sources of information, and (2) how to inform HRA practitioners with the collected HRA data. Because of these necessities, the U.S. Nuclear Regulatory Commission and the Korea Atomic Energy Research Institute independently developed two dedicated HRA data collection systems, SACADA (Scenario Authoring, Characterization, And Debriefing Application) and HuREX (Human Reliability data EXtraction), respectively. These systems provide unique frameworks that can be used to secure HRA data from full-scope training simulators of NPPs (i.e., simulator data). In order to investigate the applicability of these two systems, two papers have been prepared with distinct purposes. The first paper, entitled "SACADA and HuREX: Part 1. The Use of SACADA and HuREX Systems to Collect Human Reliability Data", deals with technical issues pertaining to the collection of HRA data. This second paper explains how the two systems are able to inform HRA practitioners. To this end, the process of estimating HEPs is demonstrated based on feed-and-bleed operations using HRA data from the two systems.

• 조명전기설비학회논문지
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• 제21권4호
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• pp.1-10
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• 2007

KH University has developed a large sky simulator which is its scale suits international standard. To verify the reliability of the sky simulator, the luminance of 36 points on the inner sky surface was measured and compared with the CIE standard overcast sky model. It was found that the sky simulator can reproduce the CIE standard overcast sky condition with 1.8[%] of mean difference. To identify the differences of daylighting performance, scale model measurements were taken under a real sky and in a sky simulator. Under overcast sky conditions, two kinds of scale model experiments were conducted by using the photometric sensor Li-cor. Firstly, a 1/20 scale model of a side-lit office room 4.9[m] wide, 7.2[m] long, and 2.6[m] high was created. Five measurement points were set at 1.2[m], 2.4[m], 3.6[m], 4.8[m], and 6.0[m] from the window. The mean difference of the light factor between the sky simulator and real sky was 7.1[%]. Secondly, a 1/30 scale model of a top-lit atrium 15[m] wide, 15[m] long, and 15[m] high was created. The measurement point was set at center of the room and the well indexes of the model were set in 5 types. The mean difference of the light factor between the sky simulator and real sky was 1.7[%]. This proved that the sky simulator is fully accurate and usable for daylighting research.

• ETRI Journal
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• 제39권3호
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• pp.364-372
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• 2017

For the reliability of controllers in a software defined network (SDN), a dynamic and self-learning schedule method (DSL) is proposed. This method is original and easy to deploy, and optimizes the combination of multiple controllers. First, we summarize multiple controllers' combinations and schedule problems in an SDN and analyze its reliability. Then, we introduce the architecture of the schedule method and evaluate multi-controller reliability, the DSL method, and its optimized solution. By continually and statistically learning the information about controller reliability, this method treats it as a metric to schedule controllers. Finally, we compare and test the method using a given testing scenario based on an SDN network simulator. The experiment results show that the DSL method can significantly improve the total reliability of an SDN compared with a random schedule, and the proposed optimization algorithm has higher efficiency than an exhaustive search.

• 전기학회논문지
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• 제61권6호
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• pp.810-816
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• 2012

As wind power has increased steadily, the importance of a condition monitoring system is being emphasized to maximize the availability and reliability of a wind turbine. To develop the advanced algorithms for fault detection and lifespan estimation, a wind turbine simulator is essential for verification of the proposed algorithms before applying them to a condition diagnosis & integrity prognosis system. The developed new-type simulator in this paper includes blades and various sensors as well as a motor, a gearbox and a generator of which the existing simulators generally consist. It also has similarity with a 3MW class wind turbine and can be used to acquire operational data from various operation conditions. This paper presents a design method of control logic for the wind turbine simulator, which gives a wind generation method and similar dynamic characteristics with the 3MW wind turbine. Finally, the proposed control logic is verified through experiments.

• 한국시뮬레이션학회논문지
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• 제8권1호
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• pp.1-18
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• 1999

Current CIM systems need to correspond flexibly to the frequent change of demands of the customers and the fast changing informations about the production environment. The demands have brought forth CIM systems developed using object-oriented technology, with reusability, expansibility, and flexibility for the system components. Due to the fact that the OO-CIM system has been developed based on an incomplete data, the constructed system must be implemented to the actual surroundings to see how pertinent it is. Hence, this paper presents an OO-simulator as a means to evaluate the pertinency and the efficiency of the developed CIM system. The OO-simulator can determine the problems likely to occur when a developed CIM system is implemented to the actual site and evaluate the efficiency beforehand. Such properties will decrease the cost of CIM system development and increase the reliability of the system. This paper presents a framework for an OO-simulator composed of a virtual factory component embodying the characteristics of a virtual factory, a connector component for the interface between the CIM system and the simulator, a configuration component for modeling the constituent structure of the CIM system, and a timer component in charge of the time advance for the simulation.

• 대한기계학회논문집A
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• 제28권5호
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• pp.593-602
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• 2004

We have developed a digital control rod control system not only to improve its performance but also to improve its reliability and speed of response so that it can replace the old fashioned analog system. However, a new developed digital control system should be tested to prove the validity by using any prototype or mock-up before application. The reliability prediction and the reliability block diagram analysis methods were adopted to verify the reliability of the developed hardware. For the case of software, especially fur a new developed control algorithm it has been tested to prove performances and validation by using a dynamic simulator and mock-up of control rod drive mechanism altogether. Here we want to present some key factors regarding to the new developed digital system with some verification procedures.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.288-291
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• 2001

Vehicle evaluation is performed on the proving ground, and durability test and dynamic test cost lots of money and time. Doing replace real vehicle experiment with similar experiment environment, it will take us much more useful advantages. Suspension simulator is required the robust and high-reliability and used widely. But it's natural of high-leveled control technique to manage to be fitted fluid system's property and complex that is for the lack of self-damping, nonlinearity, compressibility. In designing and evaluating simulator, it is important to understand the capability of kinematic and static performances. In this paper, an kinematic modeling and analysis has been presented using ADAMS to design that can reproduce longitudinal, lateral, and vertical force.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.743-746
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• 1997

The Master-Slave manipulator is the generally used remote handling equipment in the hot cell, in which the high level radioactive materials such as spent fuels are handled. To analyze the motion and to implement the training system by virtual reality technology, the simulator for M-S manipulator using the computer graphics is developed. The parts are modelled in 3-D graphics, assembled, and kinematics are assigned. The inverse kinematics of the manipulator is defined, and the slave of manipulator is coupled with master by the manipulator's specification. Also, the virtual workcell is implemented in the graphical environment which is the same as the real environment. This graphic simulator of manipulator can be effectively used in designing of the maintenance processes for the hot cell equipment and enhance the reliability of the spent fuel management.

• 동력기계공학회지
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• 제12권6호
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• pp.36-41
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• 2008

A crane is very important mechanical systems in industrial applications to move huge objects. Especially, in marine port terminals, it is used to place container boxes at desired position within given operating time. However, such system is faced with environmental disturbance such as wind from the sea, thus crane control system is required to cope with this nature. This paper proposed robust and adaptive control algorithm of a complicated 3D crane against the environmental disturbance. We simplify a mathematical design procedure to derive our control algorithm. We conduct real-time experiment using a crane simulator to evaluate its superiority and reliability.