• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.859-864
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• 2015

This paper analyzes the impact of Plug-in Electric vehicles(PEVs) on power demand and voltage change when PEVs are connected to the domestic distribution system. Specifically, it assesses PEVs charging load by charging method in accordance with PEVs penetration scenarios, its percentage of total load, and voltage range under load conditions. Concretely, we develop EMTDC modelling to perform a voltage distribution analysis when the PEVs charging system by their charging scenario was connected to the distribution system under the load condition. Furthermore we present evaluation algorithm to determine whether it is possible to adjust it such that it is in the allowed range by applying ULTC when the voltage change rate by PEVs charging scenario exceed its allowed range. Also, detailed analysis of the impact of PEVs on power distribution system was carried out by calculating existing electric power load and additional PEVs charge load by each scenario on new-town in Korea to estimate total load increases, and also by interpreting the subsequent voltage range for system circuits and demonstrating conditions for countermeasures. It was concluded that total loads including PEVs charging load on new-town distribution system in Korea by PEVs penetration scenario increase significantly, and the voltage range when considering ULTC, is allowable in terms of voltage tolerance range up to a PEVs penetration of 20% by scenario. Finally, we propose the charging capacity of PEVs that can delay the reinforcement of power distribution system while satisfying the permitted voltage change rate conditions when PEVs charging load is connected to the power distribution system by their charging penetration scenario.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.3
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• pp.162-171
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• 2014

In this study, the uncertainty analysis of present land pollutant load estimation with simplified land category in TMDLs was performed and the enhanced method for land pollutant load estimation with level II land cover consisting of 23 categories was suggested, which was verified by L-THIA model. For land TP load estimation in Jinwi stream basin, the result of comparison between existing method with simplified land category (Scenario 1) and enhanced method with level II land cover (Scenario 2) showed high uncertainty in existing method. TP loads estimated by Scenario 2 for land covers included in the site land category were in the range of 3.45 to 56.69 kg/day, in which TP loads differed by sixteen times as much among them. For application of scenario 2 to TMDLs, Land TP loads were estimated by matching level II land cover to 28 land categories in serial cadastral map (Scenario 3). In order to verify accuracy of TP load estimation by scenario 3, the simulation result of L-THIA was compared with that and the difference between the two was as little as 10%. The result of this study is expected to be used as primary data for accurate estimation of land pollutant load in TMDLs.

• ETRI Journal
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• v.33 no.3
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• pp.470-473
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• 2011

In this letter, we propose blackbox and scenario-based testing of multiplayer online games as well as simple load testing. Game testing is done from outside the source code, and the access to the source code is not required to testers because the game logic is described with a game description language and virtual game map. Instead of using a subset of the main game client for the test client, only game packet protocols and the sequence of packets are analyzed for new game testing. In addition, complex and various scenarios can be tested through combining defined actions. Scenario-based testing helps testers mimic real testing environments instead of doing simple load testing and improves the productivity of game testing.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.7
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• pp.38-48
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• 2003

Lake water quality assessment information is useful to anyone involved in lake management, from lake owners to lake associations. It provides lake water quality criteria, which can improve the ways how to manage out lake resources and how to measure current conditions. It also provides a knowledge base so that the lakes can be protected and restored. Here, the Freshwater Lake Water Quality Management System(FLAQUM) was developed. The results of FLAQUM application by scenario proved that pollutant load at rainfall by the nonpoint sources was much more than normal times at rainfall. From the result of Scenario I (pollutant source increase case), the concentrations of Boryeong freshwater lake were BOD 9.43mg/L, T-N 4.53 mg/L and T-P 0.21 mg/L, respectively, and those values exceed the standard of agricultural water. And in case of Scenario I and II(the present case) excluding Scenario III (pollutant source decrease case), all of T-N and T-P are either mesotrophication or eutrophication, on the other hand when 60% of pollution source is removed, the concentrations of Scenario III were BOD 3.21 mg/L, T-N 0.95 mg/L, T-P 0.11 mg/L, respectively, and which satisfies the standard of agricultural water quality.

• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.1
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• pp.83-101
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• 2016

This paper suggests an event-based scenario manager capable of creating and editing a scenario for shipbuilding process simulation based on multibody dynamics. To configure various situation in shipyards and easily connect with multibody dynamics, the proposed method has two main concepts: an Actor and an Action List. The Actor represents the anatomic unit of action in the multibody dynamics and can be connected to a specific component of the dynamics kernel such as the body and joint. The user can make a scenario up by combining the actors. The Action List contains information for arranging and executing the actors. Since the shipbuilding process is a kind of event-based sequence, all simulation models were configured using Discrete EVent System Specification (DEVS) formalism. The proposed method was applied to simulations of various operations in shipyards such as lifting and erection of a block and heavy load lifting operation using multiple cranes.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.5
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• pp.47-62
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• 2020

Rice paddy accounts for approximately 52.5% of all farmlands in South Korea, and it is closely related to the water environment. Climate change is expected to affect not only agricultural productivity also the water and the nutrient circulation. Therefore this study was aimed to evaluate changes of nitrogen load from rice paddy considering climate change scenario uncertainty. APEX-Paddy model which reflect rice paddy environment by modifying APEX (Agricultural Policy and Environmental eXtender) model was used. Using the AIMS (APCC Integrated Modeling Solution) offered by the APEC Climate Center, bias correction was conducted for 9 GCMs using non-parametric quantile mapping. Bias corrected climate change scenarios were applied to the APEX-Paddy model. The changes and uncertainty in runoff and nitrogen load were evaluated using multi-model ensemble. Paddy runoff showed a change of 23.1% for RCP4.5 scenario and 45.5% for RCP8.5 scenario compared the 2085s (2071 to 2100) against the base period (1976 to 2005). The nitrogen load was found to be increased as 43.9% for RCP4.5 scenario and 76.0% for RCP8.5 scenario. The uncertainty analysis showed that the annual standard deviation of nitrogen loads increased in the future, and the maximum entropy indicated an increasing tendency. And Duncan's analysis showed significant differences among GCMs as the future progressed. The result of this study seems to be used as a basis for mid- and long-term policies for water resources and water system environment considering climate change.

• Journal of Korean Society on Water Environment
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• v.30 no.4
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• pp.418-428
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• 2014

The purpose of this study is to predict the spatio-temporal changes in land uses and to evaluate land-based pollutant loads in the future under Total Water Pollution Load Management System using CLUE-S model. For these ends, sensitive parameters of conversion elasticities in CLUE-S model were calibrated and these calibrated parameters of conversion elasticities, level II land cover map of year 2009, and 7 driving factors of land use changes were used in predicting future land uses in 2002 with two scenarios(Scenario 1: non area restriction, Scenario 2: area restriction). This projected land use map of 2020 was used to estimate land-based pollutant loads. It was expected that urban areas will increase in 2020 from both scenarios 1 and 2. In Scenario 1, urban areas are expected to increase within greenbelt areas and deforest would be expected. Under Scenario 2, these phenomena were not expected. Also the results of estimation of BOD and TP pollutant loads, the BOD difference between scenarios 1 and 2 was 719 kg/day in urban areas and TP difference was 17.60 kg/day in urban areas. As shown in this study, it was found that the CLUE-S model can be useful in future pollutant load estimations because of its capability of projecting future land uses considering various socio-economic driving factors and area-restriction factors, compared with conventionally used land use prediction model.

• Wind and Structures
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• v.28 no.6
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• pp.389-404
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• 2019

In coastal regions, it is common to witness significant damages on low-rise buildings caused by hurricanes and other extreme wind events. These damages start at high pressure zones or weak building components, and then cascade to other building parts. The state-of-the-art in experimental and numerical aerodynamic load evaluation is to assume buildings with intact envelopes where wind acts only on the external walls and correct for internal pressure through separate aerodynamic studies. This approach fails to explain the effect of openings on (i) the external pressure, (ii) internal partition walls; and (iii) the load sharing between internal and external walls. During extreme events, non-structural components (e.g., windows, doors or rooftiles) could fail allowing the wind flow to enter the building, which can subject the internal walls to lateral loads that potentially can exceed their load capacities. Internal walls are typically designed for lower capacities compared to external walls. In the present work, an anticipated damage development scenario is modelled for a four-story building with a stepped gable roof. LES is used to examine the change in the internal and external wind flows for different level of assumed damages (starting from an intact building up to a case with failure in most windows and doors are observed). This study demonstrates that damages in non-structural components can increase the wind risk on the structural elements due to changes in the loading patterns. It also highlights the load sharing mechanisms in low rise buildings.

• Journal of Korean Society on Water Environment
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• v.37 no.6
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• pp.469-482
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• 2021

The recent climate change and urbanization have seen an increase in runoff and pollutant loads, and consequently significant negative water pollution. The characteristics of the pollutant loads vary among the different flow regime depending on their source and transport mechanism, However, pollutant load reduction based on flow regime perspectives has not been investigated thoroughly. Therefore, it is necessary to analyze the effects of concentration on pollutant load characteristics and reductions from each flow regime to develop efficient pollution management. As non-point pollutants continuously increase due to the increase in impervious area, efficient management is necessary. Therefore, in this study, 1) the characteristics of pollutant sources were analyzed at the Dalcheon Basin, 2) reduction of nonpoint pollution, and 3) reduction efficiency for flow regimes were analyzed. By analyzing the characteristics of the Dalcheon Basin, a reduction efficiency scenario for each pollutant source was constructed. The efficiency analysis showed 0.06% to 5.62% for the living scenario, 0.09 to 24.62% for the livestock scenario, 0.17% to 12.81% for the industry scenario, 9.45% to 38.45% for the land scenario, and 9.8% to 39.2% for the composite scenario. Therefore, various pollution reduction scenarios, taking into account the characteristics of pollutants and flow regime characteristics, can contribute to the development of efficient measurements to improve water quality at various flow regime perspectives in the Dalcheon Basin.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.511-525
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• 2021

Aluminium outfitting is widely used in offshore platforms owing to its anti-corrosion ability and its light weight. However, various standards exist (ISO, NORSOK and EN) for the design of handrails used in offshore platforms, and different suppliers have different criteria. This causes great confusion for designers. Moreover, the design load required by the standards is not clearly defined or is uncertain. Thus, many offshore projects reference previous project details or are conservatively designed without additional clarification. In this study, all of the codes and standards were reviewed and analysed through prior studies, and data on variable factors that directly and indirectly affect the handrails applied to offshore platforms were analysed. A total of 50 handrail design load scenarios were proposed through deterministic and probabilistic approaches. To verify the proposed new handrail design load selection scenario, structural analysis was performed using SACS (offshore structural analysis software). This new proposal through deterministic and probabilistic approaches is expected to improve safety by clarifying the purpose of the handrails. Furthermore, the acceptance criteria for probabilistic scenarios for handrails suggest considering the frequency of handrail use and the design life of offshore platforms to prevent excessive design. This study is expected to prevent trial and error in handrail design while maintaining overall worker safety by applying a loading scenario suitable for the project environment to enable optimal handrail design.