• Journal of the Korean Solar Energy Society
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• v.22 no.4
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• pp.26-34
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• 2002

Daylighting in building is very important as it has an effect on work performance as well as on their visual health. It is also regarded as a good energy conservation measure in saving energy used for lighting. There are many daylighting evaluation tools such as empirical equations, tables, nomograms, diagrams, protractors, computer simulation, scale models. This study conducted initial daylight measurements to analyze luminous environment in classrooms of elementary school and comparative analysis on three daylighting evaluation tools, such as daylight factor calculation formula, the graphic method with BRE Protractor and computer simulation with Adeline 3.0. It is found that the computer simulation tool produced the closest result to actual measurements of luminous environment in elementary school classroom, and the other simplified tools made appropriate results so that they can be used in the early stage of daylighting design process.

• Journal of Radiation Industry
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• v.6 no.1
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• pp.95-100
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• 2012

In this study, there has been investigated the simulation of irradiation dose using Monte Carlo methodology for the biological control of wooden cultural property. In the evaluation of fungal contamination on wooden cultural properties, Cladosporium tenuissimum, Aspergillus versicolor, Penicillium sp. were mainly identified from the Gimjeotgae. But these microorganisms were completely inactivated by 20 kGy gamma-rays. For dosimetry simulation of wooden cultural properties, Monte Carlo methodology with MCNP was used. The radiation absorbed dose distribution was predicted at 8.2~18.9 kGy. These results show that irradiation is effective for biologic control of wooden cultural properties and Monte Carlo methodology is useful for non-destructive conservation and preservation of wooden cultural properties.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05a
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• pp.349-354
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• 1996

SACOM(Simulation Analyser with Cognitive Operator Model) is being developed at Korea Atomic Energy Research Institute to simulate human operator's cognitive characteristics during the emergency situations of nuclear power plans. An operator model with error mechanisms has been developed and combined into SACOM to simulate human operator's cognitive information process based on the Rasmussen's decision ladder model. The operational logic for five different cognitive activities (Agents), operator's attentional control (Controller), short-term memory (Blackboard), and long-term memory (Knowledge Base) have been developed and implemented on blackboard architecture. A trial simulation with a scenario for emergency operation has been performed to verify the operational logic. It was found that the operator model with error mechanisms is suitable for the simulation of operator's cognitive behavior in emergency situation.

• Journal of Sensor Science and Technology
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• v.33 no.3
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• pp.134-138
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• 2024

In this study, we propose a ternary D flip-flop using tristate ternary inverters for an energy-efficient ternary circuit design of sequential logic. The tristate ternary inverter is designed by adding the functionality of the transmission gate to a standard ternary inverter without an additional transistor. The proposed flip-flop uses 18.18% fewer transistors than conventional flip-flops do. To verify the advancement of the proposed circuit, we conducted an HSPICE simulation with CMOS 28 nm technology and 0.9 V supply voltage. The simulation results demonstrate that the proposed flip-flop is better than the conventional flip-flop in terms of energy efficiency. The power consumption and worst delay are improved by 11.34% and 28.22%, respectively. The power-delay product improved by 36.35%. The above simulation results show that the proposed design can expand the Pareto frontier of a ternary flip-flop in terms of energy consumption. We expect that the proposed ternary flip-flop will contribute to the development of energy-efficient sensor systems, such as ternary successive approximation register analog-to-digital converters.

• Journal of the Korean Institute of Rural Architecture
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• v.19 no.4
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• pp.41-48
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• 2017

The objective of this study is to propose a color plan for rural villages that seeks harmony between natural and artificial environments in consideration of the fact that as new and renewable energy businesses increase drastically, problems of landscape color occur in rural areas. To this end, the current color conditions over the target regions are examined in context of energy businesses; a land simulation is developed; a survey on the preferences is conducted with the result analyzed; and finally, a color plan for villages where energy businesses and non-energy businesses are conducted. For the survey, 40 photos including simulation photos and original photos of villages were used: the photos before and after the simulation was applied were shown to village residents. The validity of the selected colors was then evaluated accordingly. The survey was conducted among 15 residents in villages where energy businesses were conducted and 15 in villages where non-energy businesses were conducted. As new and renewable energy methods such as solar energy panels are utilized over rural villages in the future, selecting artificial environmental colors that can better represent the region's identity and that are in harmony with natural environments will be an important factor in community center or housing remodeling projects, local community development projects, and so forth. It is expected that the present study can be utilized as the basis for village color plans that seek to consider actual local conditions based on objective data rather than selecting colors uniformly or based on subjective judgment.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.10a
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• pp.147-151
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• 1997

Fuel management simulation have been performed for CANFLEX-0.9％ RU fuel in the CANDU 6 reactor. In this study, the bi-directional 4-bundle shift fuelling scheme was assumed The lattice cell and time-average calculation were carried out. The refuelling simulation calculations were performed for 600 full power days. Time-averaged results show good axial power profile with the CANFLEX-RU fuel. During the simulation period, the maximum channel and bundle power were maintained below the licensing limit of CANDU 6 reactor.

• Journal of Radiation Protection and Research
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• v.48 no.4
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• pp.167-174
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• 2023

Background: A nondestructive test is commonly used to inspect the surface defects and internal structure of an object without any physical damage. X-rays generated from an electron accelerator or a tube are one of the methods used for nondestructive testing. The high penetration of X-rays through materials with low atomic numbers makes it difficult to discriminate between these materials using X-ray imaging. The interaction characteristics of neutrons with materials can supplement the limitations of X-ray imaging in material discrimination. Materials and Methods: The radiation image acquisition process for air-cargo security inspection equipment using X-rays and neutrons was simulated using a GEometry ANd Tracking (Geant4) simulation toolkit. Radiation images of phantoms composed of 13 materials were obtained, and the R-value, representing the attenuation ratio of neutrons and gamma rays in a material, was calculated from these images. Results and Discussion: The R-values were calculated from the simulated X-ray and neutron images for each phantom and compared with those obtained in the experiments. The R-values obtained from the experiments were higher than those obtained from the simulations. The difference can be due to the following two causes. The first reason is that there are various facilities or equipment in the experimental environment that scatter neutrons, unlike the simulation. The other is the difference in the neutron signal processing. In the simulation, the neutron signal is the sum of the number of neutrons entering the detector. However, in the experiment, the neutron signal was obtained by superimposing the intensities of the neutron signals. Neutron detectors also detect gamma rays, and the neutron signal cannot be clearly distinguished in the process of separating the two types of radiation. Despite these differences, the two results showed similar trends and the viability of using simulation-based radiation images, particularly in the field of security screening. With further research, the simulation-based radiation images can replace ones from experiments and be used in the related fields. Conclusion: The Korea Atomic Energy Research Institute has developed air-cargo security inspection equipment using neutrons and X-rays. Using this equipment, radiation images and R-values for various materials were obtained. The equipment was reconstructed, and the R-values were obtained for 13 materials using the Geant4 simulation toolkit. The R-values calculated by experiment and simulation show similar trends. Therefore, we confirmed the feasibility of using the simulation-based radiation image.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.436-436
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• 2009

현재 상용화되어 있는 결정질 태양전지의 경우 높은 실리콘 가격으로 인해 저가화에 어려움을 격고 있다. 따라서 태양전지 저가화의 한 방법으로 박막태양전지가 주목을 받고 있다. P-I-N 구조의 박막태양전지에서 각 층의 thickness, activation energy, energy bandgap은 고효율 달성을 위한 중요한 요소이다. 본 논문에서는 박막태양전지 P-I-N layer의 가변을 통하여 고효율을 달성하기 위한 simulation을 수행하였다. 가변 조건으로는 p-layer의 thickness, activation energy 그리고 energy bandgap을 단계별로 변화시켰고 i-layer는 thickness를 n-layer는 thickness와 activation energy를 가변하여 최적의 조건을 찾아 분석하였다. 최종 simulation 결과 p-layer의 thickness 5nm, activation energy 0.3eV 그리고 energy bandgap 1.8eV에서, i-layer thickness 400nm, n-layer thickness 30nm, activation energy 0.2eV에서 최고 효율 11.08%를 달성하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.437-437
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• 2009

현재 상용화되어 있는 결정질 태양전지의 경우 높은 실리콘 가격으로 인해 저가화에 어려움을 격고 있다. 따라서 태양전지 저가화의 한 방법으로 박막태양전지가 주목을 받고 있다. P-I-N 구조의 박막태양전지에서 I-layer 각 층의 thickness, activation energy, energy bandgap은 고효율 달성을 위한 중요한 요소이다. 본 논문에서는 박막태양전지 P-I-N layer의 가변을 통하여 고효율을 달성하기 위한 simulation을 수행하였다. 가변 조건으로는 p-layer의 thickness, activation energy 그리고 energy bandgap을 단계별로 변화시켰고 i-layer는 thickness를 n-layer는 thickness와 activation energy를 가변하여 최적의 조건을 찾아 분석하였다. 최종 simulation 결과 p-layer의 thickness 5nm, activation energy 0.3eV 그리고 energy bandgap 1.8eV에서, i-layer thickness 400nm, n-layer thickness 30nm, activation energy 0.2eV에서 최고 효율 11.08%를 달성하였다.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.3 no.1
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• pp.1-9
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• 2007

A steady-state simulation model for Dual-Source Heat Pump(DSHP) of 8RT was presented. A Dual-Source Heat Pump(DSHP) has been designed to make up for the conventional air source heat pumps. The performance evaluation has been conducted under internal standard test conditions such as ISO-13256-1 and KS C 9306. However, as test conditions such as entering water, indoor and outdoor air conditions could not be controlled to satisfy the standard test conditions in outdoor tests, a series of experiments have been conducted with the actual test conditions. Then, computer models for DSHP could be used for the standard condition have developed using EES program. The model was developed from basic thermodynamic principles and heat transfer relations. Most of the parameters were obtained with EES from the actual catalog data. The simulation results were in good agreement with the experiments.