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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of The Korean Society of Agricultural Engineers
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Journal DOI :
The Korean Society of Agricultural Engineers
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Volume & Issues
Volume 51, Issue 6 - Nov 2009
Volume 51, Issue 5 - Sep 2009
Volume 51, Issue 4 - Jul 2009
Volume 51, Issue 3 - May 2009
Volume 51, Issue 2 - Mar 2009
Volume 51, Issue 1 - Jan 2009
Selecting the target year
Comparison of Estimating Parameters by Univariate Search and Genetic Algorithm using Tank Model
Lee, Sung-Yong ; Kim, Tae-Gon ; Lee, Je-Myung ; Lee, Eun-Jung ; Kang, Moon-Seong ; Park, Seung-Woo ; Lee, Jeong-Jae ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 1~8
DOI : 10.5389/KSAE.2009.51.3.001
The objectives of this study are to apply univariate search and genetic algorithm to tank model, and compare the two optimization methods. Hydrologic data of Baran watershed during 1996 and 1997 were used for correction the tank model, and the data of 1999 to 2000 were used for validation. RMSE and R2 were used for the tank model`s optimization. Genetic algorithm showed better result than univariate search. Genetic algorithm converges to general optima, and more population of potential solution made better result. Univariate search was easy to apply and simple but had a problem of convergence to local optima, and the problem was not solved although search the solution more minutely. Therefore, this study recommend genetic algorithm to optimize tank model rather than univariate search.
Optimum Flow and Pollution Load Monitoring Time of Combined Sewers of Urban Watersheds during Dry Weather
Choi, Yong-Hun ; Won, Chul-Hee ; Park, Woon-Ji ; Seo, Ji-Yeon ; Shin, Min-Hwan ; Lee, Chan-Ki ; Choi, Joong-Dae ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 9~14
DOI : 10.5389/KSAE.2009.51.3.009
Flow and pollution load were monitored at 2 combined sewer outlets (C-1 and C-2) of urban watersheds during dry weather from September, 2004 to April, 2006 for 20 months. The objectives were to investigate the diurnal variation of flow and pollutant load and to find the proper sampling time that could measure representative flow and pollutant load. Pollution load closed to the average daily load at C-1 could be measured at 00:00 hour and by the mean of 15:00 and 18:00 hour measures, and 15:00 and 21:00 hour measures, respectively. In addition at C-2, it was 21:00 hour and the mean of 15:00 and 18:00 hour measures. This study concluded that arbitrary sampling of flow and water quality could cause large errors in the estimation of urban pollution load and recommended that urban combined sewers should be monitored when flow and water quality showed daily average and concentration.
A Study on Survey and Analysis of Green-tourism Potential in Rural Tourist Villages
Kim, Dae-Sik ; Kwon, Yong-Dae ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 15~24
DOI : 10.5389/KSAE.2009.51.3.015
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.
Estimation of Paddy Rice Evapotranspiration Considering Climate Change Using LARS-WG
Hong, Eun-Mi ; Choi, Jin-Yong ; Lee, Sang-Hyun ; Yoo, Seung-Hwan ; Kang, Moon-Seong ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 25~35
DOI : 10.5389/KSAE.2009.51.3.025
Climate change due to global warming possibly effects the agricultural water use in terms of evapotranspiration. Thus, to estimate rice evapotranspiration under the climate change, future climate data including precipitation, minimum and maximum temperatures for 90 years (
), were forecasted using LARS-WG. Observed 30 years (
) climate data and climate change scenario based on SRES A2 were prepared to operate the LARS-WG model. Using these data and FAO Blaney-Criddle method, reference evapotranspiration and rice evapotranspiration were estimated for 9 different regions in South Korea and rice evapotranspiration of 10 year return period was estimated using frequency analysis. As the results of this study, rice evapotranspiration of 10 year return period increased 1.56%, 5.99% and 10.68% for each 30 years during
) demonstrating that the increased temperature from the climate change increases the consumptive use of crops and agricultural water use.
Analysis of Spectral Reflectance Characteristics for Sand and Silt Turbid Water
Shin, Hyoung-Sub ; Lee, Kyu-Ho ; Park, Jong-Hwa ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 37~43
DOI : 10.5389/KSAE.2009.51.3.037
The objective of this study was to investigate the basic relationships between spectral reflectance and varying concentrations of sediment in surface waters. An experimental method for determining suspended sediment concentration (SSC) in the water by use of a spectroradiometer above the water surface, in visible and near-infrared (NIR) wavelengths, is applied. The main advantage of the method is the direct comparison of spectral reflectance and the SSC, but it requires an accurate knowledge of the water body and sediment. Therefore numerous spectroradiometric measurements are carried out in situ measurements, for SSC, ranging from zero to 100 percentage and two types of sediment applied in the water tank. The results indicate that the suspended sediment causes increasing spectral reflectance response in waters. We observed that spectral reflectance increases with SSC, first at the lower wavelengths (430-480 nm), then in the middle wavelengths (570-700 nm), and finally, in the NIR domain (800-820 nm); a characteristic maximum reflectance appears at 400-670 nm. Relationships between the wavelength, integral value, and the SSC were evaluated on the basis of the regression analysis. The regression curve for the relation between the wavelength, integral value, and the SSC were determined (
>0.98). Finally, the specular wavelength can be estimated to recognize the sediment and to improve SC estimation accuracy in the water.
An Equivalent Truss Model by Discretizing Continuum Structure
Lee, Sung-Yong ; Kim, Tae-Gon ; Lee, Jeong-Jae ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 45~52
DOI : 10.5389/KSAE.2009.51.3.045
Generally, structures are analyzed as continuum. However, sometimes it is more efficient to analyze structure as a discrete model rather than as a continuum model in case of the structure has complex shape or loading condition. This study, therefore, suggests an improved analysis discrete model, named Equivalent Truss Model (further as "ETM"), which can obtain similar results with analyzing continuums analysis. ETM adopts a lattice truss to compose the members of the model, and analyses the structures. As a consequence, the ETM produced the identical outcome with the continuums analysis in section force of different structures and loading conditions. Similar results have been shown in internal stress analysis as well. Make use of that ETM is discrete, fractural path of beam was analyzed by ETM and the result was reasonable.
Estimation of Reservoir Inflow Using Frequency Analysis
Maeng, Seung-Jin ; Hwang, Ju-Ha ; Shi, Qiang ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 53~62
DOI : 10.5389/KSAE.2009.51.3.053
This study was carried out to select optimal probability distribution based on design accumulated monthly mean inflow from the viewpoint of drought by Gamma (GAM), Generalized extreme value (GEV), Generalized logistic (GLO), Generalized normal (GNO), Generalized pareto (GPA), Gumbel (GUM), Normal (NOR), Pearson type 3 (PT3), Wakeby (WAK) and Kappa (KAP) distributions for the observed accumulative monthly mean inflow of Chungjudam. L-moment ratio was calculated using observed accumulative monthly mean inflow. Parameters of 10 probability distributions were estimated by the method of L-moments with the observed accumulated monthly mean inflow. Design accumulated monthly mean inflows obtained by the method of L-moments using different methods for plotting positions formulas in the 10 probability distributions were compared by relative mean error (RME) and relative absolute error (RAE) respectively. It has shown that the design accumulative monthly mean inflow derived by the method of L-moments using Weibull plotting position formula in WAK and KAP distributions were much closer to those of the observed accumulative monthly mean inflow in comparison with those obtained by the method of L-moment with the different formulas for plotting positions in other distributions from the viewpoint of RME and RAE.
Alternative Methods for Classification on Weathered Strata
Son, Young-Hwan ; Noh, Soo-Kack ; Kim, Seong-Pil ; Chang, Pyoung-Wuck ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 63~69
DOI : 10.5389/KSAE.2009.51.3.063
The undisturbed specimens used in this research were sampled in the field by the sequential sampling method. In addition, four testing methods were applied to identify for the characteristics and classification of weathered strata. N-value by standard penetration test was obtained from in the field and then analyzed using normalization method. Other methods such as X-ray grain size distribution, X-ray fluorescence spectroscopy(XRF), and fall cone test were carried out in the lab. These analyzed results indicate that distribution of particle, composition of minerals are changed in accordance with the degree of weathering, unusual strata and depth. Consequently, the weathered strata can be extensively separated into two parts according to the test results and each part was shown different in the strata characteristics. It can be prospected that mechanical characteristics should be different, even though mechanical tests were not applied. Furthermore, these results not only make up for the error by one testing method but also contribute more effectively and economically to the design and the construction.
Development of a Gable-roofed Prefabricated Pipe-house for Improvement of Snow Endurance
Yang, In-Kyoo ; Nam, Sang-Woon ;
Journal of The Korean Society of Agricultural Engineers, volume 51, issue 3, 2009, Pages 71~78
DOI : 10.5389/KSAE.2009.51.3.071
Pipe section of bending part at the arch type pipe-house showed an ellipse with oblateness of 0.076 on the average. Flexural rigidity of bending part decreased by average 6.3% than that of an original round shape section. The deflection of arch type pipe-house measured by model experiments showed much bigger than the result of structural analysis. In case of arch type pipe-house, we supposed that the decrease of flexural rigidity for the bending part of pipes had an effect on deflection of roof under the working load. This effect should be considered in the structural analysis. Bending resistance of gable type pipe-house used a prefabricated connector which developed in this study showed about
times stronger than that of the existing arch type or gable type processed bending. Therefore, we supposed that the gable-roofed prefabricated pipe-house is safer than arch type or bent gable type in case of heavy snowfall. According to house scales and section properties of steel pipe in use, safe snow depths and rafter intervals were presented for design of gable-roofed prefabricated pipe-house. Their standards were established in the range of the durable models recommended by RDA, and the comparative examinations were conducted by means of structural analysis. It was evaluated that the developed greenhouse model had a high applicability in the field.