• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.69-80
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• 2002

This study aims to develop a potential centrality evaluation model (PCEM) which can evaluate the potential centrality of villages within the catchment boundaries. PCEM is a tool for evaluation of villages\` centralities by the potential centrality index (PCI) developed in this study. For quantification of PCI, total 31 evaluation criteria on the accessibility to other villages and the natural and human environment of the village were introduced. The weighting values of criteria were calculated from the step wise pair-comparision results of 14 specialists in academic fields on rural planning using by AHP (Analytic Hierachy Process) of MCE (multi-criteria evaluation) method. In the results, the weighting values of the spatial accessibility, the natural environments and the human environments were 448, 338 and 214, respectively, among total value being 1,000.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.4
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• pp.64-74
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• 1997

The purpose of this study is to analyze hydraulic characteristics of surface irrigation in a paddy field of direct seeding culture. Field experiment was performed in the paddy field of ridge direct dry seeding. Simulation by a numerical model was also accomplished with the data obtained from the field experiment. The model was developed by one dimensional zero-inertia equation and finite difference method. From the result of the field observation, the furrows of the experimental field were found to have various geometric characteristics. Advance distance and time were measured both in the field and by the model simulation for various furrow lengths and irrigation discharges. Roughness coefficients of each furrow were also estimated by the model.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.1
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• pp.81-92
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• 2002

The purpose of this paper, the 2nd stage of this study. is to test the applicability of the potential centrality evaluation model (PCEM) to a case study area. To verify the practical applicabilities of the PCEM, an administrative area of Ucheon-myeon, Hoengseong-gun, Gangwon-do was selected as a study area. Full data on the human environments of total 72 villages within the study area were surveyed. Data on the natural environments were collected through GIS analysis from digital maps developed far this study. The highest PCI (Potential Centrality Index) score was shown at Uhang village of which one being 841 (total score being 1,000), the real single center village of the study area. The evaluation results on potential centeralities of all the villages in the study area would provide decision-makers with more precised information for selection of center villages for development project.

• Journal of The Korean Society of Agricultural Engineers
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• v.58 no.6
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• pp.79-92
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• 2016

The objective of this study is to classify the types of rural areas (138 $si{\cdot}gun$) considering settlement environment by Decision Tree Method (CHAID). The CHAID method was used for decision tree algorithm and the seven dependant variables and 5 explanatory variables were selected, respectively. By decision tree method, rural areas were finally classified into six groups through three separate processes. City area, lower area in aging rate and higher area in farmland area ratio was analyzed to be relatively rich rather than other area in the case of settlement environment index. In the future, this study will be able to utilize as a reference to the planning of rural development projects.

• Journal of the Korean Society of Combustion
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• v.23 no.1
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• pp.13-20
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• 2018

Transverse acoustic mode in annular combustion chambers affects air-fuel mixing characteristics in the nozzle and can result in heat release fluctuations in the combustor. In addition, the acoustic mode coupling between the nozzle and the combustion chamber is one of the key parameters determining combustion instability phenomenon in the annular combustor. In this study, acoustic coupling between the nozzle and annular combustor was numerically analyzed using 3D-based in house FEM code. As a result, it was found that the acoustic mode inside the combustion chamber at anti-node locations of the transverse mode was strongly influenced by the nozzle inlet boundary conditions.

• Journal of the Korean Society of Combustion
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• v.23 no.1
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• pp.28-35
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• 2018

Entropy waves(or hot spots) in a gas turbine combustor are generated by irregular heat release from flames, then can be coupled with acoustic waves when they are accelerated at the exit of the combustor. This coupling mechanism between the entropy and the acoustic waves is generally known to be one of the triggers for combustion instability, which is commonly called "indirect" combustion noise. This paper reviews the fundamental theories on generation, propagation, and coupling with acoustic field of entropy waves and recent research results on the indirect combustion noise for gas turbine combustors.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.2
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• pp.112-121
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• 2001

In this study, a spatial location-allocation model of center villages (SLAMCV) was developed for selecting spatial center villages and allocating their rear villages. In SLAMCV, rural space was considered as a network with villages for nodes and roads for connecting lines. For quantification of residents’ accessibilities in the network, a disutility index (DUI) was developed and used, which is dependent upon travelling distance between the center and its hinter villages, design vehicle speed in connecting road and population of hinter villages. SLAMCV was verified to Christaller’s hexagonal hierachical settlement system to test the theoretical reasonability and computing algorithm of the model.

• Magazine of the Korean Society of Agricultural Engineers
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• v.44 no.5
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• pp.67-78
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• 2002

The purpose of this study is to apply land use planning model (LUPM) to a test village. The LUPM was tested to Uhang village, Ucheon-myeon, Gangwon-do, and its parameters calibrated by land use data from 1973 to 1980. When two test cases were considered of its extended built areas of 10,600㎡ from 1980 to 1985 and 51,300㎡ from 1985 to 1992, there was good similarities between simulated and observed results with R$^2$ being more than 0.95. Land use transfer patterns to residential use could be very similarly simulated from LUPM when comparing the observed patterns, so, LUPM can be applied to the comprehensive simulation of land use change due to the village growth.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.6
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• pp.55-62
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• 2007

Actual states of energy utilizations were investigated and analyzed on three representative rural villages in Chungcheongnam-Do. Rural residents were almost using the ondol boiler as a heating facility and oil(diesel, kerosene) and electricity(night thermal-storage power service) as a heating energy. There were a few households using briquette or firewood in a fuel hole with Korean hypocaust. Most of their cooking facilities were gas ranges using LPG. The most popular hot-water supply system was an oil boiler and the next was an electricity boiler. The amount of energy use in a rural household generally showed 20,000 to 40,000 won/month of the electric power rate, 400 to 800 liter/year of the oil and 60 to 120 kg/year of the LPG. Prompt measures should be taken to promote the spread of new and renewable energy such as solar heat, biomass and wind power, etc.

• 한국연소학회:학술대회논문집
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• 2001.06a
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• pp.187-192
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• 2001

A homogeneous premixed charge compression ignition engine is experimentally investigated for the reduction of exhaust emissions in diesel engines. In this study, the premixed fuel is injected into the intake manifold to form homogeneous pre-mixture in the combustion chamber and then this pre-mixture is ignited by small amount of diesel fuel directly injected into the cylinder. In the premixed charge compression ignition engine, NOx and smoke concentration of the exhaust emissions were reduced simultaneously as compared with the conventional diesel engine. But HC and CO emissions were increased with the increase of premixed ratio. The combustion characteristics of premixed charged diesel engine such as the power output, the rate of heat release, and the other characteristics are discussed.