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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of The Korean Society of Agricultural Engineers
Journal Basic Information
Journal DOI :
The Korean Society of Agricultural Engineers
Editor in Chief :
Volume & Issues
Volume 54, Issue 6 - Nov 2012
Volume 54, Issue 5 - Sep 2012
Volume 54, Issue 4 - Jul 2012
Volume 54, Issue 3 - May 2012
Volume 54, Issue 2 - Mar 2012
Volume 54, Issue 1 - Jan 2012
Selecting the target year
Overall Heat Transfer Coefficient Measurement of Covering Materials with Thermal Screens for Greenhouse using the Hot Box Method
Diop, Souleymane ; Lee, Jong-Won ; Na, Wook-Ho ; Lee, Hyun-Woo ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 1~7
DOI : 10.5389/KSAE.2012.54.5.001
Bond Properties of Structural Poly Vinyl Alcohol Fiber in Cement Based Composites with Metakaolin and Silica Fume Contents
Lee, Jung-Woo ; Park, Chan-Gi ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 9~16
DOI : 10.5389/KSAE.2012.54.5.009
In this study, the effect of metakaoline and silica fume on the bond performances of structural polyvinyl alcohol (PVA) fiber in cement mortar, including bond strength, interface toughness, and microstructure analysis are presented. Metakaoline and silica fume contents ranging from 0 % to 15 % are used in the mix proportions. Pullout tests are conducted to measure the bond performance of PVA fiber from cement mortar. Test results showed the incorporation of metakaoline and silica fume can effectively enhance the PVA fiber-cement mortar interfacial properties. Bond strength and interface toughness increased with metakaoline and silica fume content up to 10 % in cement mortar and decreased when the metakaoline and silica fume content reached 15 %. The microstructural observation confirms the findings on the interface bond mechanism drawn from the fiber pullout test results.
Optimizing Rules for Releasing Environmental Water in Enlarged Agricultural Reservoirs
Yoo, Seung-Hwan ; Lee, Sang-Hyun ; Choi, Jin-Yong ; Park, Tae-Seon ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 17~24
DOI : 10.5389/KSAE.2012.54.5.017
The main purposes of the agricultural reservoir enlargement (ARE) project are to secure water supply reliability (WSR) for agriculture and to release environmental water during dry seasons. In this study, an operational rule that will simultaneously satisfy both the above issues was developed. Initial amount of water storage at the beginning of non-irrigation season (1st October) was divided into 3 stages, and the target level of water storage at the beginning of irrigation seasons (1st April) was set up. Required operational curves and release amounts were estimated based on the stages and target water levels. To evaluate the applicability of this rule, the amount of water released for environmental purposes and WSRs were analyzed for three reservoirs (Unam, Jangchi and Topjeong). The ratio between annual amount of release and additional amount of water storage were 1.6, 1.85, and 4.1 for the Unam, Jangchi, Tapjeong reservoirs, respectively. Also, the WSRs of all reservoirs were found to become higher than when the design standard was applied. Therefore, it is considered that the proposed rule is more suitable for the enlarged agricultural reservoirs operation as it satisfies the WSRs while securing the environmental water release.
Effect of Mineral Admixture on Bond between Structural Synthetic Fiber and Latex Modified Cement Mortar under Sulfate Environments
Kim, Dong-Hyun ; Lee, Jung-Woo ; Park, Chan-Gi ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 25~34
DOI : 10.5389/KSAE.2012.54.5.025
It has been well known that concrete structures exposed to acid and sulfate environments such as sewer etc. show significant decrease in their durability due to chemical attack. Such deleterious acid and sulfate attacks lead to expansion and cracking in concrete, and thus, eventually result in damage to cement mortar by forming expansive hydration products due to the reaction between cement hydration products and acid and sulfate ions. In this study, the effect of fly ash and blast furnace slag on the bond performances of structural synthetic fiber in latex modified cement mortar under sulfate environments. Fly ash and blast furnace slag contents ranging from 0 % to 20 % are used in the mix proportions. The latex modified cement mortar specimens were immersed in fresh water, 8 % sodium sulfate (
) solutions for 28 and 50 days, respectively. Pullout tests are conducted to measure the bond performance of structural synthetic fiber from latex modified cement mortar after sulfate environments exposure. Test results are found that the incorporation of fly ash and blast furnace slag can effectively enhance the PVA fiber-latex modified cement mortar interfacial bond properties (bond behavior, bond strength and interface toughness) after sulfate environments exposure. The microstructural observation confirms the findings on the interface bond mechanism drawn from the fiber pullout test results under sulfate environments.
Projection of Paddy Rice Consumptive Use in the Major Plains of the Korean Peninsula under the RCP Scenarios
Chung, Sang-Ok ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 35~41
DOI : 10.5389/KSAE.2012.54.5.035
The paddy rice consumptive use in the six plains of the Korean peninsula was projected with changing climate under the representative concentration pathway (RCP) scenarios. High resolution climate data for the baseline (1961-1990) was obtained from the International water management institute (IWMI) and future high resolution climate projection was obtained from the Korea Meteorological Administration. Reference evapotranspiration (ET) was calculated by using Hargreaves equation. The results of this study showed that the average annual mean temperature would increase persistently in the future. Temperatures were projected to increase more in RCP8.5 than those in RCP4.5 scenario. The rice consumptive use during the growing period was projected to increase slightly in the 2020s and then more significantly in the 2050s and 2080s. It showed higher values for RCP8.5 than for RCP4.5. The rice consumptive use after transplanting in the study areas would increase by 2.2 %, 5.1 % and 7.2 % for RCP4.5 and 3.0 %, 7.6 %, and 13.3 % for RCP8.5, in the 2020s, 2050s, and 2080s, respectively, from the baseline value of 534 mm. The results demonstrated the effects of climate change on rice consumptive use quite well, and can be used in the future agricultural water planning in the Korean peninsula.
The Prediction of Compressive Strength of Sedimentary Rock using the Artificial Neural Networks
Lee, Sang-Ho ; Kim, Dong-Rak ; Seo, In-Shik ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 43~47
DOI : 10.5389/KSAE.2012.54.5.043
A evaluation for the strength of rock includes a lot of uncertainty due to existence of discontinuity surface and weakness plain in the rock mass, so essential test results and other data for the resonable strength analysis are absolutely insufficient. Therefore, a analytical technique to reduce such uncertainty can be required. A probabilistic analysis technique has mainly to make up for the uncertainty to investigate the strength of rock mass. Recently, a artificial neural networks, as a more newly analysis method to solve several problems in the existing analysis methodology, trends to apply to study on the rock strength. In this study the unconfined compressive strength from basic physical property values of sedimentary rock, black shale and red shale, distributed in Daegu metropolitan area is estimated, using the artificial neural networks. And the applicability of the analysis method is investigated. From the results, it is confirmed that the unconfined compressive strength of the sedimentary rock can be easily and efficiently predicted by the analysis technique with the artificial neural networks.
Cooling Efficiency of Low Pressure Compressed Air Fogging System in Naturally Ventilated Greenhouses
Nam, Sang-Woon ; Kim, Young-Shik ; Sung, In-Mo ; Ko, Gi-Hyuk ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 49~55
DOI : 10.5389/KSAE.2012.54.5.049
In order to derive the efficient utilization of low pressure compressed air fogging system, cooling efficiencies with control types were analyzed through cooling experiments in tomato greenhouses. The control types were set up with temperature control, humidity control, temperature and humidity control, and time control. It showed that the cooling effects were 0.7 to
on average and maximum of 4.3 to
, the humidification effects were 3.5 to 13.5 % on average and maximum of 14.3 to 24.4 %. Both the cooling and humidification effect were the highest in the time control method. The cooling efficiency of the air fogging system was not high with 8.3 to 27.3 % on average. However, the cooling efficiency of 24.6 to 27.3 % which appears from the time control is similar to the cooling efficiency of high pressure fogging system experimented in Japan. The air fogging system is operated by low pressure, but its efficiency is similar to high pressure. We think because it uses compressed air. From this point of view, we suggest that the air fogging system can get the cooling efficiency of similar levels to that of high pressure fogging system and it will have an advantage from clogging problem of nozzle etc.
Decision Making Model for Agricultural Reservoir using PROMETHEE-AHP
Choi, Eun-Hyuk ; Bae, Sang-Soo ; Jee, Hong-Kee ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 57~67
DOI : 10.5389/KSAE.2012.54.5.057
This paper presents the Multi Criteria Decision Making (MCDM) to evaluate water resources plan for agricultural reservoir. Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE) and Analytic Hierarchy Process (AHP) were used to estimate weight and priority of alternatives to find out the most reasonable and efficient way of water resources assessment. The 6 criteria that both decision maker and beneficiary are satisfied have been identified to secure agricultural water resources and then the priority of 10 subcriteria was set. An enhanced PROMETHEE-AHP model was used to perform pairwise comparison and find out the priority of each alternative because the existing decision making model have uncertainty and ambiguity. Comparison analysis of decision making models was carried out to find a way of suitable decision making and validity of PROMETHEE-AHP model was suggested.
Application of Penetration in Fall Cone Test to Estimate Relative Density with Variation of Water Content for Sand
Choi, Woo-Seok ; Son, Young-Hwan ; Park, Jae-Sung ; Noh, Soo-Kack ; Bong, Tae-Ho ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 69~77
DOI : 10.5389/KSAE.2012.54.5.069
Relative density, used to express dynamics condition of sand quantitatively, is measured by RI Test, Standard Penetration Test and Cone Penetration Test. Each measurement method has demerits, which is complicated or needs a specific analysis instrument and an analysis of expert. Also the ground is in wet condition commonly because of an unsaturated zone between a saturated zone and a surface, so the behaviour of the ground has different engineering properties unlike the dry ground and it diminishes accuracy of measuring relative density. In this study, the correlation between relative density and penetration of fall cone test in dry condition and wet condition with variation of water content was analyzed and a simple measuring method for relative density was suggested. As a result, there were difference of penetration between dry sands and wet sands, the correlation between relative density and penetration showed linear expression and relative density could be measured by the linear relation.
Evaluation and CFD Modelling of Flow behind Livestock Ventilation Fan for Small-Scale Wind Power Generation
Hong, Se-Woon ; Lee, In-Bok ; Seo, Il-Hwan ; Kwon, Kyeong-Seok ; Ha, Tae-Hwan ; Hwang, Hyun-Seob ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 79~89
DOI : 10.5389/KSAE.2012.54.5.079
The objectives of this paper were to evaluate the wind flow behind the livestock ventilation fan for small-scale wind power generation and to make flow profiles of imaginary ventilation fan for future simulation works. The field experiments using typical 50-inch fan indicated that the wind flow behind the ventilation fan had a good possibility of power generation with its high and steady wind speeds up to a distance of 2 m. The expected electricity yield was almost 101~369 W with a small (0.8 m radius) wind turbine. The decline of ventilation fan performance caused by the obstacle was also not significant with about 4 % from a distance of 2 m. The flow profiles for the computational fluid dynamics (CFD) simulation was created by combining the direction vectors analyzed from tuft visualization test and the flow predicted by the rotating fan modeling. The flow profiles are expected to provide an efficient saving of computational time and cost to design a better wind turbine system in future works.
Utility of Gridded Observations for Statistical Bias-Correction of Climate Model Outputs and its Hydrologic Implication over West Central Florida
Hwang, Sye-Woon ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 91~102
DOI : 10.5389/KSAE.2012.54.5.091
Full-Scale Model Test of Vertical Drain Materials using Recycled Aggregates and Crushed Stone
Lee, Dal-Won ; Lee, Jeong-Jun ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 103~111
DOI : 10.5389/KSAE.2012.54.5.103
In this study, the full-scale laboratory model test on utilization of recycled aggregates and crushed stone as vertical drains to use an alternative material of sand in soft ground is performed. The settlement and pore water pressure were measured to evaluate the discharge capacity and filed application, and the results were compared and analyzed through the finite element method. The measured and estimated settlement in all vertical drain materials decreases gradually with the load increase. The measured settlement 6.55~8.63 mm, and the estimated by the Hyperbolic model was 7.45~7.92 mm. So the model used for the analysis can be applied to the settlement estimation of the actual field. The variations of pore water pressure with time showed constantly regardless of the load in all vertical drainage materials. The pore water pressure was similarity to that of sand after rapid drawdown. Therefore, it was applicable to the field because discharge capacity was enough to be an alternative material to the sand which had been being used as the vertical drains.
Flow Characteristics of Lateral Irrigation Canals Diverted from Kimje Main Canal in Dongjin Irrigation Area
Choi, Jin-Kyu ; Son, Jae-Gwon ; Kim, Jin-Taek ; Kim, Young-Joo ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 113~121
DOI : 10.5389/KSAE.2012.54.5.113
The study was carried out to investigate the dimension of irrigation canal, and measure the water flow of those diverted from Kimje main canal in Dongjin irrigation area. The rating curves indicating the relationships between water level and discharge of the lateral canals were induced using the measured data with high regression coefficients of 0.957~0.999 at inlet points and 0.932~0.998 at end points, respectively. And Manning's roughness coefficients were estimated as the ranged from 0.015 to 0.074 at inlet points and 0.056 to 0.089 at end points with rectangular type of concrete open irrigation canals, the Manning's roughness coefficients of the end points were less than those values of the end points, which may be considered as the deposition of the bottom sediments.
Estimating Vulnerable Duration for Irrigation with Agricultural Water Supply and Demand during Residual Periods
Nam, Won-Ho ; Kim, Tae-Gon ; Choi, Jin-Yong ; Lee, Jeong-Jae ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 123~128
DOI : 10.5389/KSAE.2012.54.5.123
For optimal reservoir operation and management, there are essential elements including water supply in agricultural reservoir and demand in irrigation district. To estimate agricultural water demand and supply, many factors such as weather, crops, soil, growing conditions cultivation method and the watershed/irrigation area should be considered, however, there are occurred water supply impossible duration under the influence of the variability and uncertainty of meteorological and hydrological phenomenon. Focusing on agricultural reservoir, amount and tendency of agricultural water supply and demand shows seasonally/regionally different patterns. Through the analysis of deviation and changes in the timing of the two elements, duration in excess of water supply can be identified quantitatively. Here, we introduce an approach to assessment of irrigation vulnerable duration for effective management of agricultural reservoir using time dependent change analysis of residual water supply and irrigation water requirements. Irrigation vulnerable duration has been determined through the comparison of water supply in agricultural reservoir and demand in irrigation district based on the water budget analysis, therefore can be used as an improved and basis data for the effective and intensive water management.
Analysis of Rainfall Induced Infiltration Considering Occluded Air in Unsaturated Soils
Lee, Joon-Yong ; Yu, Chan ; Kim, Uk-Gie ; Kim, Dong-Wook ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 129~139
DOI : 10.5389/KSAE.2012.54.5.129
Accurate modeling rainfall induced landslide and slope stability requires a detailed knowledge of the distribution of material strength characteristics and suction distribution. However, material properties obtained from the drying cycle are still used for infiltration analysis in many cases, even though material properties of wetting cycle are quite different from those of drying cycle due to hydraulic hysteresis and air occlusion. Therefore, the selection of proper material properties such as soil-water retention curve (SWRC) and the hydraulic conductivity function (HCF) reflecting characteristics of wetting cycle and air occlusion is an essential prerequisite in order to simulate the infiltration phenomena and to predict the suction and water content distribution in unsaturated soils. It is concluded that the simulation of infiltration with material properties from the drying cycle did not reasonably match with experimental outputs. Further discussion is made on how to describe the material properties considering air occlusion during wetting cycle over the entire suction range in order to simulate infiltration phenomena.
Application of a Non-stationary Frequency Analysis Method for Estimating Probable Precipitation in Korea
Kim, Gwang-Seob ; Lee, Gi-Chun ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 141~153
DOI : 10.5389/KSAE.2012.54.5.141
In this study, we estimated probable precipitation amounts at the target year (2020, 2030, 2040) of 55 weather stations in Korea using the 24 hour annual maximum precipitation data from 1973 through 2009 which should be useful for management of agricultural reservoirs. Not only trend tests but also non-stationary tests were performed and non-stationary frequency analysis were conducted to all of 55 sites. Gumbel distribution was chosen and probability weighted moment method was used to estimate model parameters. The behavior of the mean of extreme precipitation data, scale parameter, and location parameter were analyzed. The probable precipitation amount at the target year was estimated by a non-stationary frequency analysis using the linear regression analysis for the mean of extreme precipitation data, scale parameter, and location parameter. Overall results demonstrated that the probable precipitation amounts using the non-stationary frequency analysis were overestimated. There were large increase of the probable precipitation amounts of middle part of Korea and decrease at several sites in Southern part. The non-stationary frequency analysis using a linear model should be applicable to relatively short projection periods.
Physical Properties and Characteristics of Freezing of the Sub-base Materials with a Grain Size Distribution
Chae, Chang-Woo ; Song, Chang-Seob ;
Journal of The Korean Society of Agricultural Engineers, volume 54, issue 5, 2012, Pages 155~160
DOI : 10.5389/KSAE.2012.54.5.155
In this paper it was analyzed that the mechanical properties, the permeability and the freezing properties of SB-2 materials which are mainly used with the subbase materials. To this ends, a series of the physical test, the permeability test and the freezing test were carried out the samples mixed the small aggregate and the big aggregate from which was re-classified the SB-2. From the test results, it was analyzed the characteristics of permeability and the characteristics of freezing of the samples. And it was reviewed for SB-2 materials that the use of possibility for the freezing prevention layer material.