• Information Display
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• v.25 no.2
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• pp.10-14
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• 2024

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.633-634
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• 2015

주파수조정용 배터리 에너지저장장치의 주파수조정용으로써의 효용성을 확인하기 위해 한국전력공사 전력연구원 ESS연구사업단에서는 제주시 조천변전소에 4MW급 ESS실증단지의 조성과 제어시스템의 실증을 완료하였다. 이후 주파수조정용 대용량 에너지저장장치 운전제어기술을 개발하여 서안성, 신용인 변전소에 설치된 52MW ESS에 각각 주파수추종운전용 28MW와 자동발전제어용 24MW 제어시스템기술을 적용시켰다. 대용량 에너지저장장치 운전제어기술을 개발하기 위하여 제어시스템과 연계할 수 있는 시뮬레이션이 가능한 에너지저장장치 및 전력계통을 개발하여 시험하였다. 본 논문에서는 제어시스템과 연계 가능하고, 운전원 인터페이스를 제공하며, 시뮬레이션이 가능한 전력계통과 에너지저장장치로 구성된 제어기 검증용 시뮬레이터 개발에 대하여 소개하고자 한다.

• Journal of Energy Engineering
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• v.21 no.3
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• pp.211-220
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• 2012

In study to investigate losing energy of building in window, we analyze the heating loss parts in the material of structure throughout modeling of window system. Also, by making modeling in the building using simulation, we investigate the heating load variation of building in window. According to the type of windows and the material of structure, we analyze the energy variation of building and a temperature variation.

• Journal of the Korea Society for Simulation
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• v.17 no.4
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• pp.123-131
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• 2008

Many researches have been actively performed to increase energy efficiency in wireless sensor networks. In these researches communication has been the most important target for reducing energy consumption. In fact, in most cases, the frequencies of communication and sensing in a sensor node affect its energy consumption. Therefore, sensing period and transmission period need to be controlled to increase energy efficiency. This paper proposes on energy efficient and restricted query flooding mechanism using service discovery. Further, we implement node management system based on the mechanism and evaluate its performance.

• Journal of the Korean Society for Marine Environment & Energy
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• v.1 no.2
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• pp.82-95
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• 1998

In this paper, two series of numerical simulations are performed using LS/DYNA3D: The first series of numerical simulations are collision events between a 310,000 DWT double hull VLCC (struck ship) and two 35,000 and 105,000 DWT tankers (striking ships). Collisions are assumed to occur at the middle of the VLCC with the striking ships moving at right angle to the YLCC centerline. The second ones, grounding accidents of two 40,000 DWT Conventional and Advanced Double Hull lanker bottom structures, CONV/PD328 and ADH/PD328 models. The overall objective of this study is to understand the structural failure and energy absorbing mechanisms during collision and grounding events for double hull tanker side and bottom structures, which lead to the initiation of inner shell rupture and cause the kinetic energy dissipation to bring the ship to a stop. These numerical simulations will contribute to the estimation of damage extents of collision and grounding accidents and the future improvements in lanker safety at the design stage.

• Journal of the Korea Society for Simulation
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• v.16 no.3
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• pp.49-56
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• 2007

There are many application areas of wireless sensor networks, such as combat field surveillance, terrorist tracking and highway traffic monitoring. These applications collect sensed data from sensor nodes to monitor events in the territory of interest. One of the important issues in these applications is the existence of the radio-jamming zone between source nodes and the base station. Depending on the routing protocol the transmission of the sensed data may not be delivered to the base station. To solve this problem we propose a genetic algorithm based routing method for reliable transmission while considering the balanced energy depletion of the sensor nodes. The genetic algorithm finds an efficient routing path by considering the radio-jamming zone, energy consumption needed fur data transmission and average remaining energy level. The fitness function employed in genetic algorithm is implemented by applying the fuzzy logic. In simulation, our proposed method is compared with LEACH and Hierarchical PEGASIS. The simulation results show that the proposed method is efficient in both the energy consumption and success ratio of delivery.

• Progress in Medical Physics
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• v.10 no.2
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• pp.73-81
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• 1999

Scatter correction for single photon emission computed tomography (SPECT) plays an important role to improve image quality and quantitation. The purpose of this study was to investigate three scatter correction methods using Monte Carlo simulation. Point source and Jaszack phantom filled with Tc-99m were simulated by Monte Carlo code, SIMIND. For scatter correction, we applied three methods, Compton window (CW) method, triple window (TW) method, and dual photopeak window (DPW) method. Point sources located at various depths along the center line within a 20-cm phantom were simulated to calculate the window ratios and corresponding scatter fractions by evaluating the polynomial coefficients for DPW method. Energy windows were located in W$_1$=92-125 keV, W$_2$=124-126 keV, W$_3$=136-140 keV, W$_4$=140-141 keV, and W$_{5}$=154-156 keV. The results showed that in Jaszack phantom with cold sphere and hot sphere, the TW gave the closest contrast and percentage recovery to the ideal image, respectively, while CW overestimated and DPW underestimated the contrast of ideal one. All three scatter correction methods showed an improved image contrast. In conclusion, scatter correction is essential for improving image contrast and accurate quantification. The choice of scatter correction method should be made on the basis of accuracies and ease of implementation.

• Journal of the Korea Society for Simulation
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• v.30 no.1
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• pp.113-126
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• 2021

The future energy consumption pattern will show a very different pattern from the present due to the increase of distributed power sources such as renewable energy and the birth of the concept of prosumers, etc. Accordingly, it can be predicted that the direction of establishment of an appropriate production and supply plan considering the stability and consumption efficiency of the entire power grid will also be different from now. This paper proposes a simulation model that can test a new operational strategy when faced with a number of possible future environments. Through the proposed model, it is possible to simulate and analyze power consumed and supplied in a future Smart Grid environment, in which a large amount of new concepts including energy storage service (ESS) and distributed energy resources (DER) will be added. In particular, it is possible to model complex systems structurally by using DEVS formalism among the ABM (Agent-Based Model) methodologies that can model decision-making for each agent existing in the grid, and several factors can be easily added to the grid. The simulation model was verified using given dataset in the current situation, and scenario analysis was performed by simply adding an ESS, one of the main elements of the smart grid, to the model.

• Journal of Digital Contents Society
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• v.19 no.4
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• pp.815-819
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• 2018

In this study, we investigate balance of a biped robot applying Foot Placement Estimator (FPE) in simulation. FPE method is used to determine a stable foot location for balancing the biped robot when an initial orientation of the robot body is statically unstable. In this case, the 6-DOF biped robot with point foot is modelled considering contact and friction between foot and the ground. For simulation, the mass of the robot is 1 kg assuming the center of robot mass (COM) is located at the center of the robot body. The height from the ground to the COM is 1 m. Robot balance is achieved applying stable foot locations calculated from FPE method using linear and angular velocities, and the height of the COM. The initially unstable angular postures, $5^{\circ}$ and $-5^{\circ}$, of the robot body are simulated. Simulation results confirm that the FPE method provides stable balance of the robot for all given unstable initial conditions.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.1-8
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• 2014

Cloud computing helps big data processing to make various information using IT resources. The government has to start the RPS(Renewable Portfolio Standard) and induce the production of electricity using renewable energy equipment. And the government manages system to gather big data that is distributed geographically. The companies can purchase the REC(Renewable Energy Certificate) to other electricity generation companies to fill shortage among their duty from the system. Because of the RPS use voluntary competitive market in REC trade and the prices have the large variation, RPS is necessary to predict the equitable REC price using RPS big data. This paper proposed REC price prediction method base on fuzzy logic using the price trend and trading condition infra in REC market, that is modeled in cloud computing environment. Cloud computing helps to analyze correlation and variables that act on REC price within RPS big data and the analysis can be predict REC price by simulation. Fuzzy logic presents balanced REC average trading prices using the trading quantity and price. The model presents REC average trading price using the trading quantity and price and the method helps induce well-converged price in the long run in cloud computing environment.