• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.5
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• pp.757-764
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• 2017

As the reduction of greenhouse gases(GHGs) emission has become a global issue, the microgrid markets are growing rapidly. With the sudden changes in the market, Korean government suggested a new business model called 'Self-Sufficient Energy Islands'. Its main concern is a stand-alone microgrid composed of Distributed Energy Resources(DERs) such as Renewable Energy Sources(RESs), Energy Storage System(ESS) and Fuel Cell, in order to minimize the emission of GHGs. According to these trend, this paper is written to propose an optimal sizing method of DERs in a stand-alone microgrid by using Genetic Algorithm(GA), one of the representative stochastic methods. It is to minimize the net present cost with the variables, size of RESs and ESS. In the process for optimization, the sunless days are considered as additional constraints. Through the case study analysis, the size of DERs installed in a microgrid system has been computed using the proposed method in MATLAB. And the result of MATLAB is compared with that of HOMER(Hybrid Optimization of Multiple Energy Resources), a well-known energy modeling software.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.77-84
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• 2007

This study aims to analyze temporal variation of rural tourist potential in village level. In order to analyze the temporal variation, this study applied a green-tourism potential evaluation model(GPEM) to a study area, Namilmyun with 18 villages, which located on county of Kumsan, province of Chungnam. GPEM consists of two factors about human resources, which is quantified by resident population of the village who will be participated in village management for green-tourism, and amenity resources, which is calculated by an evaluation table with 31 criteria and their weighting values. Data surveying for the study area was performed at August 2003 and 2006, respectively, in order to quantity the 31 evaluation criteria of GPEM. From the analysis results, the amenity resources with three sub-classes of industrial, natural, and social resources showed that the evaluation values of 2006 were increased in more than those of 2003, displaying the increase rate of ranging from 108% to 112% in the three sub-classes, except of one village in social resources and three village in natural resources with reduction. In human resources, the evaluation values of 2006 were highly increased more than those of 2003, showing the rate of 556% in the gradient of linear regression line. In green tourism potential in each village, the evaluation results for two time series showed that the potential is increased by time, which the increase rate of the potential is 114%. Ultimately, the results of this study enable us to realize that the green-tourism potential in each village over time is increased, for example, due to developing new facilities in the village by investment of government and participating in rural tourism by resident people over time. From the analysis and results, the methodology of this study can be applied to analyze the temporal variation of the potential for villages having investment from government.

• YAKHAK HOEJI
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• v.52 no.1
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• pp.73-78
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• 2008

Immune system can protect host attacking from a variety of microorganism and virus through innate and adaptive immunities. The innate immune system can be activated by recognition of conserved carbohydrates on the cell surface of pathogen resulting in protection, immunity regulation and inflammation. Immunostimulating and anti-tumor ${\beta}$-glucan, major cell wall component of many fungi, could be recognized as pathogen associated molecular pattern (PAMP) by C-type lectin such as pathogen recognition receptor (PRR) of host innate immunity cells. In spite of many studies of basidiomycetes ${\beta}$-glucan on immunostimulation, little is known about the precise mechanism as molecular-level. Among C-type lectins, dectin-1 was cloned and reported as a ${\beta}$-glucan receptor. In this report, we demonstrated induction of cytokine gene transcription by Ganoderma lucidum ${\beta}$-glucan in the absence or presence of lipopolysaccharide (LPS) by RT-PCR analysis. The expression of murine dectin-1 (MD-1) on RAW264.7 macrophage by RT-PCR showing both the full length, 757 bp $(MD-1{\alpha})$ and alternative spliced form, 620 bp $(MD-1{\beta})$. Both $MD-1{\alpha}$ and $MD-1{\beta}$ mRNAs were induced by ${\beta $-glucan both in the absence and presence of LPS. To explore expression of inflammatory cytokines by ${\beta}$-glucan, RAW264.7 cells were treated with ${\beta}$-glucan for 12 hours. As a result, the expressions of IL-1 IL-6, IL-l0 and $TNF-{\alpha}$ were increased by ${\beta}$-glucan treatment in a dose-dependent fashion. From these results, ${\beta}$-glucan induced transcriptions of dectin-1 and immune activating cytokine genes, indicating induction of immune allertness by expressing dectin-1 and secreting inflammatory cytokines.

• Journal of Adhesion and Interface
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• v.3 no.2
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• pp.17-29
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• 2002

Interfacial properties and microfailure degradation mechanisms of the bioabsorbable composites for implant materials were investigated using micromechanical technique and measurement of surface wettability. As hydrolysis time increased, the tensile strength, the modulus and the elongation of poly(ester-amide) (PEA) and bioactive glass fibers decreased, whereas those of chitosan fiber almost did not change. Interfacial shear strength (IFSS) between bioactive glass fiber and poly-L-lactide (PLLA) was much higher than PEA or chitosan fiber/PLLA systems using dual matrix composite (DMC) specimen. The decreasing rate of IFSS was the fastest in bioactive glass fiber/PLLA composites whereas that of chitosan fiber/PLLA composites was the slowest. Work of adhesion, $W_a$ between bioactive glass fiber and PLLA was the highest, and the wettability results were consistent with the IFSS. Interfacial properties and microfailure degradation mechanisms can be important factors to control bioabsorbable composite performance.

• Journal of Chest Surgery
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• v.32 no.2
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• pp.211-214
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• 1999

We experienced a case of thymolipoma that is a rare benign mediastinal tumor, composed of normal thymic tissue and matured adipose tissue. A 46-years-old woman was admitted to the department of medicine due to lower abdominal pain. Simple chest PA showed a large mass shadow at right cardiac border. Chest CT scanning showed well defined large fatty mass at right cardiac border which was suggested thymolipoma. The mass was resected and confirmed as thymolipoma histopathologically.

• Korean Journal of Optics and Photonics
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• v.10 no.5
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• pp.430-438
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• 1999

We have utilized soft-aperturing by gain media to develop a high-power tunable Ti:Sapphire laser with sub-40-fs and broad tuning range. The tunable spectral range was only limited by the bandwidth of mirrors. We made use of knife-edge slits near an intra-cavity prism controlled by micro-stepping-motors to tune the center wavelength continuously. The tunability of the center wavelength was ranged from 770 nm to 870 nm, and the measured pulsewidth was sub-40 fs throughout the above spectral range. The shortest pulsewidth was about 17 fs at the center wavelength of 820 nm and the spectral bandwidth was 72 nm. At 5 W pumping power of the Ar-ion laser we obtained average output power of 440 mW~580 mW. For the cw and Kerr-lens mode-lodking conditions, we have evaluated the value of an amplitude modulation to be ${\gamma}=2.5{\times}10^{-8}/W$ from the calculated waists of a Gaussian beam on the Ti:sapphire crystal surface. Using this result we demonstrate that the generation of sub-40-fs Kerr-lens mode-locked pulse can be described by the Ginzberg-Landau model which is a weak pulse shaping model.

• Spatial Information Research
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• v.3 no.2
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• pp.135-146
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• 1995

The purpose of this study is to develop a GIS application and interface model (GISCELWAB) for the temporal and spatial simulation of surface runoff from a small watershed. The model was constituted by three sub - models : The input data extraction model (GISINDATA) which prepares cell-based input data automatically for a given watershed, the cell water balance model(CELWAB) which calculates the water balance for a cell and simulates surface runoff of watershed simultaneously by the interaction of cells, and the output data management model(GISOUTDISP) which visualize the results of temporal and spatial variation of surface runoff. The input data extraction model was developed to solve the time-consuming problems for the input-data preparation of distributed hydrologic model. The input data for CELWAB can be obtained by extracting ASCII data from a vector map. The output data management model was developed to convert the storage depth and discharge of cell into grid map. This model ean-bles to visualize the temporal and spatial formulation process of watershed storage depth and surface runoff wholly with time increment.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.5
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• pp.46-53
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• 2017

This paper deals with an acoustic model for a lean premixed gas turbine combustor composed of three stages: premixing chamber, nozzle and flame tube. Our model is given as an acoustic transfer function whose input is a heat release rate perturbation and output is a velocity perturbation at a flame location. We have shown that the resonance frequencies are functions of three round-trip frequencies of acoustic wave in each stage, and area ratios between stages. By analyzing poles of the acoustic transfer function, we could characterize resonant frequencies and their dependency on various system parameters of a combustor. It was found that our analytic findings match with existing numerical and experimental results in literature.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.523-534
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• 2010

This paper aims to develop a revitalized strategy for Daecheongdong district located on surrounding area of Daecheong dam, which general development projects are restricted by the acts of Green-belt area and Water supply protection zone. The study area consists of 13 villages in Donggu, Daejeon city. This study performed not only survey of amenity and human resources in the whole study area, but also development of new strategy integrating $1^{st}$, $2^{nd}$, and $3^{rd}$ industries for agriculture with potential. In the sample survey to 11% of village people, the new strategy was accepted positively with 88% of Understanding and 65% of Agreement in answer. The composition plans of farming association and total brand in the study area were agreed by 30% of residents with strong opinion. Representative groups of people living in Donggu, outside of the study area, have also positive opinion of 86% for Purchasing of agricultural products, 89% of Experience tourism, and 61% of Corporation for the study area, which the answering rate was 11% among 326 people. Finally, this study also investigated the corresponding Acts on performing of the new projects extracted in this study.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.535-542
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• 2010

The purpose of this study was to survey and diagnostic the self-related health cognition, stress, culture life and health-related fitness for residents of rural area. For this study, Total 126 people answered by a written questionnaire and took part in health-related fitness test for old adults in rural area. According to the normal distribution, the indexes were divided into five grades(very poor 5, poor 4, average 3, good 2, very good 1). The self-related health cognition(SF-36) was third grades. The index was as same as average old adults in rural area. The old adults stress level was third grades. The degrees of stress were as same as average old adults in rural area. The participation in the culture life was fourth grades. The health-related fitness test were third-fifth grades. The results of this experiment could be functioned as a very important fundamental source in order to establish satisfying health system, social welfare for the old people in rural area. Taken together, it seemed that self-related health cognition, stress level, participation in the culture life and health-related fitness have to be considered and improved. The indexes should be further investigated and some practical method should be developed for the olded people in rural area.