• Journal of The Korean Society of Agricultural Engineers
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• v.51 no.3
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• pp.15-24
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• 2009

This study tried to develop a tentative evaluation system on greentourism potentials(GTP) of rural villages. The GTP evaluation system consisted of 45 detail criteria within three kinds of large scale criteria, which are human resources of residents capability, amenity resources of tourists attraction, and income resources through exchange activity between rural and urban areas. The evaluation criteria were adapted from several decades existing studies considering the hardware(facility and amenity resources) and software(human resources and programs on tourism)resources in rural villages. Two kinds of test study areas, which are subdivisions of county in a typical rural area(Boori) and an suburbanized area surrounding a big city(Chooboo), located on Keumsan county in Chungnam province, were selected to test the GTP evaluation system. The results showed that the average GTP values of each village in Boori are higher than those of Chooboo, due to higher values in criteria on amenity resources and income resources, which the typical rural area may have higher value in such criteria.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.27-35
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• 2008

This study aims to estimate the optimal probability distribution of daily electricity generation by wind power, in order to contribute in rural green-village planning. Wind power generation is now being recognized as one of the most popular sources for renewable resources over the country. Although it is also being adapted to rural area for may reasons, it is important to estimate the magnitudes of power outputs with reliable statistical methodologies while applying historical daily wind data, for correct feasibility analysis. In this study, one of the well-known statistical methodology is employed to define the appropriate statistical distributions for monthly power outputs for specific rural areas. The results imply that the assumption of normal distributions for many cases may lead to incorrect decision-making and therefore lead to the unreliable feasibility analysis. Subjective methodology for testing goodness of fit for normal distributions on all the cases in this study, provides possibilities to consider the other various types of statistical distributions for more precise feasibility analysis.

• Journal of The Korean Society of Agricultural Engineers
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• v.50 no.6
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• pp.37-47
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• 2008

Photovoltaic power generation is currently being recognized as one of the most popular sources for renewable resources over the country. Although it is also being adapted to rural area for may reasons, it is important to estimate the magnitudes of power outputs with reliable statistical methodologies, while applying historical daily solar energy data, for correct feasibility analysis. In this study, one of the well-known statistical methodologies is employed to define the appropriate probability distributions for monthly power outputs for the selected rural area, county of Seo-san, province of Chungnam. The results imply that the assumption of normal distributions for several months may lead to incorrect decision-making and therefore lead to the unreliable feasibility analysis. Generalized beta and triangular distributions were found to be superior to normal distribution, when describing monthly probability distributions for daily photovoltaic power. Based on the appropriate distributions resulted from this study, Monte Carlo simulation technique was also applied to provide additional flexible information for the relevant decision makers. This study found out new finding that the probability distributions should be considered to make planning of the photovoltaic power system in rural village unit, in order to give reasonable economic analysis to the decision makers.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.1
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• pp.56-62
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• 2007

Lennox-Gastaut syndrome(LGS) is a severe age-specific epilepsy syndrome that causes medication-resistant seizures in childhood. Vagal nerve stimulation (VNS) has been proposed as a possible way to improve the treatment of refractory epilepsy. We treated 9 patients with Lennox-Gastaut syndrome between the ages of 2 and 11 years (mean 5.8 years), by using the vagus nerve stimulation. The mean follow-up duration was 35 months. The mean reduction of seizure frequency compared with baseline before VNS was 52% after 6 months (range, 0% to 89%; P<0.011), and 58% after 1 year (range 0% to 89%; P<0.012). Seven patients showed improvements of quality of life (QOL) such as alertness, mood, and language skills. The most common side effects were transient hoarseness (6 patients) and drooling (1 patient). Our results suggest that the vagus nerve stimulation could be an effective and safe adjunct therapy for the treatment of Lennox-Gastaut syndrome.

• Journal of The Korean Association For Science Education
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• v.9 no.2
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• pp.47-53
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• 1989

The standard of chair and desk is decided to design a science laboratory which would help students giving the chance to show their ability and participating spontaneously. The standard is come by the middle school students physical size of the 1986 national physical standard and they are classified into large, medium and small size. The size of laboratory is determined by the size of desk. the distance between desks and the number of students accommodated. By the middle school students physical standard, the heights of chair are 32, 34, 37cm and the widths of chair are 35, 37, 40cm. The desks heights are 53, 58, 63cm and the size is $110{\times}160cm$. The distance between rear and front of desk is 120cm and the left and right side of desk is 150cm. When 24, 36, 60 students are accommodated in laboratory, the size of laboratories are $9.6{\times}10.5m$, $12.7{\times}10.5m$ and $18.8{\times}10.5m$ respectively.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.6
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• pp.32-40
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• 2012

For predicting eigenfrequency and initial growth rate of combustion instabilities in lean premixed gas turbine combustor, linear thermoacoustic analysis model was developed in the current paper. A model combustor was selected for the model validation, which has well-defined inlet and outlet conditions and a relatively simple geometry, compared to the combustor in the previous works. Analytical linear equations for thermoacoustic waves were derived for a given combustion system. It was found that the prediction results showed a good agreement with the measurements, even though there was underestimation for instability frequencies. This underestimation was more obvious for a longer flame (i.e. wider temperature distribution) than for a shorter flame.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.35-40
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• 2011

An experimental study of the flame response in a turbulent premixed combustor has been conducted in order to investigate mechanisms for combustion instabilities in a lean premixed gas turbine combustor. A lab-scale combustor and mixing section system were fabricated to measure the flame transfer function. Measurements are made of the velocity fluctuation in the nozzle using hot wire anemometry and of the heat release fluctuation in the combustor using chemiluminescence emission. The results show that the flame transfer functions are greatly dependent on the modulation frequency as well as operating conditions such as equivalence ratio. Flame dynamics can be generalized as a function of Strouhal number which is a ratio of flame length to modulation wave length.

• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.3
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• pp.72-80
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• 2018

Combustion instabilities are caused by the feedback relationship between heat release perturbations and acoustic pressure oscillations in the combustor. Studies on the combustion instability in an annular combustor have recently received great attention due to the enhanced NOx requirement in aero-engines. In this study, a thermoacoustic network model was developed in order to calculate the acoustic characteristics for various modes in the annular combustor. The network model is combined with flame transfer function(FTF) in order to calculate the stability of the combustor. Numerical results are compared with measurement data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.3_4
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• pp.23-33
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• 1995

Geographic data which are difficult to handle by the characteristics of spatial variation and variety turned into a possibility to analyze with tlie computer-aided digital map and the use of Geographic Information System(GIS). The purpose of this study is to develop and apply a GIS application model (GISCELWAB) for the spatial simulation of surface runoff from a small watershed. This paper discribes the modeling procedure and the applicability of the cell water balance model (CELWAB) which calculates the water balance of a cell and simulates surface runoff of watershed simultaneously by the interaction of cells. The cell water balance model was developed to simulate the temporal and spatial storage depth and surface runoff of a watershed. The CELWAB model was constituted by Inflow-Outflow Calculator (JOC) which was developed to connect cell-to-cell transport mechanism automatically in this study. The CELWAB model requests detail data for each component of a cell hydrologic process. In this study, therefore, BANWOL watershed which have available field data was selected, and sensitivity for several model parameters was analyzed. The simulated results of surface runoff agreed well with the observed data for the rising phase of hydrograph except the recession phase. Each mean of relative errors for peak discharge and peak time was 0.21% and2.1 1% respectively. In sensitivity analysis of CELWAB , antecedent soil moisture condition(AMC) affected most largely the model.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.4
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• pp.85-98
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• 2002

The purpose of this study is to develop a land use planning model (LUPM) which can be applied to development of rural villages considering their spatial expansion. The LUPM finds out and allocates the new built site required for the improvement of existing villages. in the development of LUPM, CA (cellular automata) and land suitability analysis methods were applied combinedly. The model uses basically numerical data of CIS based on grid data. Agglomerated settlement, as a type of village for simulation, was adopted. Probability of land use change for optimizing development area was calculated by the six criteria: slope. drainage characteristic, direction of slope, as absolute suitability of grid itself, distance from road. distance from stream and distance from the village center, as relative probability by neighborhood cells. Weighting values of these criteria were quantified by AHP (analytic hierarchy process) method, which is one of MCE(multi-criteria evaluation) method. The algorithm of the model was verified by three example villages: an isolation village, a village with horizontal road, and a village with nodal point of cross road