• Proceedings of the KIEE Conference
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• 2005.04a
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• pp.268-270
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• 2005

A tendency to erect more wind turbines can be observed in order to reduce the environmental consequences of electric power generation. As a result of this, in the near future, wind turbines may start to influence the behavior of electric power systems by interacting with conventional generation and loads. Therefore, wind turbine models that can be integrated into power system simulation software are needed. In this paper, a model that can be used to represent all types of variable speed wind turbines in power system simulations is presented. Wind turbine characteristic equation of a wind turbine is implemented in the RTDS, and the real data of weather conditions are interfaced to the RTDS for the purpose of real time simulation of grid-connection wind power system. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme in this paper. The results show that the cost effective verifying for the efficiency and stability of WPGS.

• Smart Structures and Systems
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• v.25 no.1
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• pp.23-35
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• 2020

It is important to take into account the thermal behavior in assessing the structural condition of bridges. An effective method of studying the temperature effect of long-span bridges is numerical simulation based on the solar radiation models. This study aims to develop a time-varying solar radiation model which can consider the real-time weather changes, such as a cloud cover. A statistical analysis of the long-term monitoring data is first performed, especially on the temperature data between the south and north anchors of the bridge, to confirm that temperature difference can be used to describe real-time weather changes. Second, a defect in the traditional solar radiation model is detected in the temperature field simulation, whereby the value of the turbidity coefficient t_u is subjective and cannot be used to describe the weather changes in real-time. Therefore, a new solar radiation model with modified turbidity coefficient γ is first established on the temperature difference between the south and north anchors. Third, the temperature data of several days are selected for model validation, with the results showing that the simulated temperature distribution is in good agreement with the measured temperature, while the calculated results by the traditional model had minor errors because the turbidity coefficient t_u is uncertainty. In addition, the vertical and transverse temperature gradient of a typical cross-section and the temperature distribution of the tower are also studied.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1696-1698
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• 2005

In this paper, a model that can be used to represent all types of variable speed wind turbines in power system simulations is presented. Wind turbine characteristic equation of a wind turbine is implemented in the RTDS, and the real data of weather conditions are interfaced to the RTDS for the purpose of real time simulation of grid-connection wind power system. The outcomes of the simulation demonstrate the effectiveness of the proposed simulation scheme in this paper. The results show that the cost effective verifying for the efficiency and stability of WPGS.

• Journal of the Korea Society for Simulation
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• v.26 no.3
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• pp.73-86
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• 2017

Environmental data plays an important role to enhance the reliability of experimental results in M&S(Modeling and Simulation). Especially in Military M&S, extreme weather events can be used for virtual training and simulation importantly. However, the environmental data is huge and it is dispersed among multiple organizations. It is difficult for M&S operators to select the date and area where the weather phenomenon occurs in the real environmental data and to acquire them. Environmental data retrieval technology based on Fuzzy criteria is one of the important technologies for developing Environmental Scenario Generator. As a result of this study, a fuzzy retrieval algorithm composed of four main parameters(RV, MF, FRA, and MRV) was presented. This study suggests that the RV can be used as 14 m/s for wind speed and 80 mm/d for precipitation to search the date of storm accompanied by high wind. The MF, the FRA, and MRV can be used sigmoid, 0.2, and 1 respectively. The algorithm proposed in this study is expected to be very useful for searching the date on which weather phenomena necessary for simulation occurred.

• International Journal of Internet, Broadcasting and Communication
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• v.6 no.2
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• pp.20-24
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• 2014

These days the large-scale car accidents have often been occurred by overspeeding in disregard of sharp curve, foggy and freezing regions. This paper has proposed the algorithm to calculate the safety speed in real time that can protect the car accidents under these weather and road conditions using Fuzzy reasoning theory. Under raining and snowing, drivers have to slow down the traffic safety speed by 1/3 of the traffic safety speed indicated on the existing speed sign plate based on their decision. So it is difficult to calculate and then observe the safety speed. This paper has performed the simulation that provides the deivers with the optimal safety speed considering the road and weather conditions in real time to improve these problems. We have proved this method can improve more 25% than the existing one.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.1342-1344
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• 2002

Wind is a significant and valuable renewable energy resource. It is safe and abundant and can make an important contribution to future clean, sustainable and diversified electricity supplies. Unlike other sources of energy, wind does not pollute the atmosphere nor create any hazardous waste. In some countries wind energy is already competitive with fossil and nuclear power even without accounting for the environmental benefits of wind power. The cost of electricity from conventional power stations does not usually take full account of its environmental impact (acid rain, oil slick clean up, the effects of climate change, etc). In this paper, a transient phenomenon simulation method for Wind Power Generation System(WPGS) under real weather conditions has been proposed. The simulation method is expected to be able to analyze easily under various conditions with considering the sort of wind turbine, the capacity of system and the converter system. Wind turbine connected to the synchronous generator and power converter was simulated.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.279-283
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• 2009

Distributed generation(DG) of combined cooling, heat. and power(CCHP)has been gaining momentum in recent year as efficient, secure alternative for meeting increasing energy demands. This paper presents the energy performance of microturbine CCHP system equipped with an absorption chiller by modelling it in hospital building. The orders of study were as following. 1)The list and schedule of energy consumption equipment in hospital were examined such as heating and cooling machine, light etc. 2) Annual report of energy usage and monitoring data were examined as heating, cooling, DHW, lighting, etc. 3) The weather data in 2007 was used for simulation and was arranged by meteorological office data in Daejeon. 4) Reference simulation model was built by comparison of real energy consumption and simulation result by TRNSYS and ESP-r. The energy consumption pattern of building were analyzed by simulation model and energy reduction rate were calculated over the cogeneration. As a result of this study, power generation efficiency of turbine was about 30% after installing micro gas turbine and lighting energy as well as total electricity consumption can be reduced by 40%. If electricity energy and waste heat in turbine are used, 56% of heating energy and 67% of cooling energy can be reduced respectively, and total system efficiency can be increased up to 70%.

• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.36-42
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• 2023

The development of autonomous vehicles are currently being actively carried out by various companies and research institutes. Expectations for commercialization in daily life as well as specific industries are also rising. Simulators for autonomous vehicles are an essential element in algorithm development and execution considering stability and cost. In this need, various simulators and platforms for simulators are emerging, but research on simulations that reflect various meteorological environmental factors in the real world is still insufficient. This paper proposes a traffic simulation for autonomous vehicles that can consider the weather environment. The weather environment that can be set is largely classified into four categories, and an improved collision prevention algorithm to apply them is presented. Simulation development was conducted through Carla's Python API, a development tool for autonomous driving, and the performance results were compared with existing collision algorithms. Through this, we tried to propose improvements for the development of advanced self-driving vehicle simulations that can reflect various weather environmental factors in real life.

• Journal of Construction Engineering and Project Management
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• v.4 no.2
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• pp.31-40
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• 2014

The management of vehicular supply of "perishable" construction material, such as concrete mixes, faces a series of uncertainties such as weather, daily traffic patterns and accidents. Presented in this paper is a logistics control model for managing a hauling fleet with interrelated processes at both ends and queue capacities. Discrete event simulation is used to model the complex interactions of production units and the randomness of the real world. Two alternative strategies for ready mix concrete delivery, with and without an off-site waiting queue, are studied to compare supply performance. Secondly, the paper discusses the effect of an agent-based GPS tracking system providing real-time travel data that lessens the uncertainty of trucking time. The results show that the combination of GPS information with off-site queuing reduces productivity loss and process wastes of concrete placement as well as the idleness of supply trucks when crew or pump experience an unexpected stoppage.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.2
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• pp.81-86
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• 2014

In this paper, we states the verification and validation methodology for the modular system of A-SMGCS which defined in the ICAO Manual on Advanced Surface Movement Guidance and Control Systems. Such systems aim to maintain the declared surface movement rate under all weather conditions while maintaining the required level of safety. With the complete concept of an A-SMGCS, air traffic controllers, vehicle drivers, flight crews, and are assisted with surface operations in terms of surveillance, control, routing/planning and guidance tasks. A-SMGCS verification and validation for the development of Real Time Simulation, shadow mode trials, operational trials are conducted through three methods. In this study, the characteristics and the need for such a verification method was examined.