• International conference on construction engineering and project management
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• 2009.05a
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• pp.276-284
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• 2009

As an on-going research project, Zero Net Energy Test Home (ZNETH) project investigates effective approaches to achieve whole-house environmental and energy goals. The main research objectives are (1) to identify energy saving solutions for designs, materials, and construction methods for the ZNETH house and (2) to verify whether ZNETH house can produce more energy than the house uses by utilizing Building Information Modeling (BIM) and energy analysis tools. The initial project analysis is conducted using building information modeling (BIM) and energy analysis tools. The BIM-driven research approach incorporates architectural and construction engineering methods for improving whole-building performance while minimizing increases in overall building cost. This paper discusses about advantages/disadvantages of using BIM integrated energy analysis, related interoperability issues between BIM software and energy analysis software, and results of energy analysis for ZNETH. Although this investigation is in its early stage, several dramatic outcomes have already been observed. Utilizing BIM for energy analysis is an obvious benefit because of the ease by which the 3D model is transferred, and the speed that an energy model can be analyzed and interpreted to improve design. The research will continue to use the ZNETH project as a testing bed for the integration of sustainable design into the BIM process.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.282-289
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• 2017

Background: To investigate the possibility of using Asarum sieboldii as an environment-friendly fumigant for protecting organic cultural heritages, the inhibitory effect of A. sieboldii extract against wood rot fungi on Hanji was examined. Methods and Results: The physical, optical, and morphological properties of Hanji inoculated with Trametes versicolor and Tyromyces palustris, and exposed to the n-hexane fraction of A. sieboldii extract, were measured. The physical properties were expressed as weight loss, zero-span tensile strength and viscosity and the optical properties were depicted by luminance and chromaticity ($L^*$, $a^*$, and $b^*$). The results showed that, the n-hexane fraction of A. sieboldii extract inhibited the growth of fungi on Hanji, and preserved its condition. At a concentration of 25 mg, the n-hexane fraction of A. sieboldii extract maintained zero-span tensile strength, increased viscosity, and restricted discoloration of Hanji. It also was confirmed that the weight of fungi infested Hanji exposed to the extract did not decrease. Scanning electron microscopic images revealed that the spores and hyphae of T. versicolor and T. palustris were not present on Hanji during treatment with > 25 mg of the n-hexane fraction of A. sieboldii extract. Conclusions: These results indicate that the n-hexane fraction of A. sieboldii extract by virtue of its antifungal effectiveness may help in preserving Korean paper cultural heritages, including Hanji.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6391-6396
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• 2015

In order to investigate characteristics of the von Mises yield criterion under 2 dimensional stress condition, two cases of plane strain were studied. One of which was for zero elastic strain and the other was for zero plastic strain increment. Yield functions for the plane strain condition for zero elastic strain and for the plane stress condition were represented as ellipse and the two yield functions were compared by ratios of major axis, minor axis and eccentricity and it was seen that the ratio of minor axis was the same between the two cases and the ratios of major axis and eccentricity were functions of Poisson's ratio. Region of elastic behavior obtained from considering plane strain condition of zero elastic strain increases as the Poisson's ratio increases. Yield function for plane strain obtained from considering zero plastic increment and associate flow rule was displayed as straight line and the region of elastic behavior was greater than that for the case of plane stress.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.4
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• pp.140-145
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• 2008

Silicon single crystals are grown by Czochralski (CZ) method in different growing conditions. The different shapes of the crystal-melt interface are obtained with various magnetic fields. Effects of zero-Gauss plane (ZGP) shape and magnetic intensity (MI) on the crystal-melt interface in the crystal experimentally are investigated. The shape of ZGP is not only flat but also parabolic, which is due to magnetic ratio (MR) of the lower to upper current densities in the configurations of the cusp-magnetic fields. As the MR increases, the crystal-melt interface becomes more concave. It means that the hot melt can be easily transported to the crystal-melt interface with increasing the MR. Effective shape of the crystal-melt interface is found to depend on the magnetic field in cusp-magnetic CZ method. The experimental results are compared with other studies and discussed.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.545-567
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• 2018

This study applied and compared Poisson model, negative binomial model, zero inflated Poisson model, and zero inflated negative binomial model to estimate determinants of employed labour quantity. To estimate each of models, this study used fisheries census data which were obtained at microdata integrated service running by Statistics Korea. The study selected zero inflated negative binomial model according to the Vuong test and Likelihood-ratio test. In addition, the study estimated fishing village's practical changes on employed labour quantity as analyzing changes from 2010 to 2015. The results showed that the household with fishing vessels and high selling price had a significant effect on decrease of the labour quantities. Meanwhile, the longer work experience of the household, the more significant the increase in the labour quantities. In conclusion, this study presented that capitalized fishing household and the acceleration of aging had a significant impact on the change in the labour quantities.

• Journal of Magnetics
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• v.6 no.4
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• pp.132-141
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• 2001

The switching characteristics and the magnetization-flop behavior in magnetic tunnel junctions exchange biased by synthetic antiferromagnets (SyAFs) are investigated by using a computer simulations based on a single-domain multilayer model. The bias field acting on the free layer is found to be sensitive to the thickness of neighboring layers, and the thickness dependence of the bias field is greater at smaller cell dimensions due to larger magnetostatic interactions. The resistance to magnetization flop increases with decreasing cell size due to increased shape anisotropy. When the cell dimensions are small and the synthetic antiferromagnet is weakly, or not pinned, the magnetization directions of the two layers sandwiching the insulating layer are aligned antiparallel due to a strong magnetostatic interaction, resulting in an abnormal magneto resistance (MR) change from the high-MR state to zero, irrespective of the direction of the free-layer switching. The threshold field for magnetization-flop is found to increase linearly with increasing antiferromagnetic exchange coupling in the synthetic antiferromagnet. Irrespective of the magnetic parameters and cell sizes, magnetization flop does not exist near zero applied field, indicating that magnetization flop is driven by the Zeeman energy.

• Journal of Mechanical Science and Technology
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• v.18 no.10
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• pp.1712-1721
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• 2004

A method of measuring the thermal diffusivity of semi-infinite solid material at room temperature using photothermal displacement is proposed. In previous works, within the constant thickness of material, the thermal diffusivity was determined by the magnitude and phase of deformation gradient as the relative position between the pump and probe beams. In this study, however, a complete theoretical treatment of the photothermal displacement technique has been performed for thermal diffusivity measurement in semi-infinite solid materials. The influence of parameters, such as, radius and modulation frequency of the pump beam and the thermal diffusivity, was studied. We propose a simple analysis method based on the zero -crossing position of real part of deformation gradient and the minimum position of phase as the relative position between two beams. It is independent of parameters such as power of pump beam, absorption coefficient, reflectivity, Poisson's ratio, and thermal expansion coefficient.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.130-136
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• 2009

A lumped parameter model of Li-ion battery in hybrid electric vehicle(HEV) is constructed and system parameters are identified by using recursive least square estimation for different C-rates, SOCs and temperatures. The system characteristics of pole and zero in frequency domain are analyzed with the parameters obtained from different conditions. The parameterized model of Li-ion battery indicates highly dependant of temperatures. The system pole and internal resistance changes 6.6 and 18 times at $-20^{\circ}C$, comparing with those at $25^{\circ}C$, respectively. These results will be utilized on constructing model-based state observer or an on-line identification and an adaptation of the model parameters in battery management systems for hybrid electric vehicle applications.

• New & Renewable Energy
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• v.18 no.3
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• pp.72-84
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• 2022

As the threat of climate change escalates, 'net-zero' has become a priority for the international community, and the use of new and renewable energy sources is expected to play a significant role in reaching international carbon neutrality. Here, we evaluate technological competitiveness in terms of implementation and technology by analyzing scientific literature and patents in the new and renewable energy fields of five major countries. For the past 10 years (2009-2019), the most active areas of new and renewable energy research and development have been solar power, wind power, waste, and fuel cells. China is the forerunner in implementation, whereas the United States has the most advanced technology. Portfolio analysis revealed that Korea's fuel cell, the United States' bioenergy, China's waste, Japan's solar and fuel cell, and the European Union's wind power have shown to be in Star Field respectively. Technological competitiveness analysis found that Korea is lagging behind other countries in the new and renewable energy sector, and needs to set a new direction for future carbon-neutral research and development, investment, and policy.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.469-482
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• 2013

This study identified problems of the existing ecosystem-based fisheries assessment approach, and suggested new methods for scoring risk and for the estimation of fishery risk index. First, risk scores of zero to two for target and limit reference points for each indicator were replaced by those of zero to three, and the risk scores were calculated from new formulae which were developed in this study. Second, a new method for estimating fishery risk index (FRI) was developed in this study, considering the level of indicators. New method was applied to the Korean large purse seine fishery, large pair trawl fishery and drag net fishery. More precise and detailed risk scores were obtained from the new method, which can explain the risks by the wider range of both risk levels for 'better than target' and 'beyond limit'. The new method for estimating FRI could avoid the basic problem related with duplicated computations of fishery-level indicators, which improved the estimated FRI to be more accurate. Also, a method for estimating variance of FRI using the bootstrap was proposed in this study.