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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 52, Issue 6 - Nov 2010
Volume 52, Issue 5 - Sep 2010
Volume 52, Issue 4 - Jul 2010
Volume 52, Issue 3 - May 2010
Volume 52, Issue 2 - Mar 2010
Volume 52, Issue 1 - Jan 2010
Selecting the target year
Comparison of Coefficient of Consolidation and Prediction of Excess Pore Water Pressure of Agricultural Reservoir under Embankment on Soft Ground
Lee, Dal-Won ; Kim, Eun-Ho ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 1~9
DOI : 10.5389/KSAE.2010.52.2.001
This study was carried out to comparison of coefficient of consolidation and the prediction of excess pore water pressure in agricultural reservoir on soft clay ground. For the purpose of verification of the proposed equation, laboratory model tests and field tests were performed and excess pore water pressure was compared to those predicted with the Terzaghi`s method. The predicted excess pore water pressure according to ponding was very applicable to practice because it was close to the observed data. Also, for the comparison of coefficient of consolidation, the oedometer, constant rate of strain (CRS), and Rowe cell tests were performed. The coefficient of consolidation at the Rowe cell and CRS tests showed a greate increase than in the oedometer test. The ratio of the vertical and horizontal coefficient of consolidation showed a large difference according to various tests method and mixing ratio. Therefore, it is recommended that careful attention should be paid to predicting the required consolidation period in agricultural reservoir.
Reinforcing Effect of Thin-wall at Serviceability Condition
Kim, Doo-Hwan ; Yoon, Seong-Soo ; Park, Jin-Seon ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 11~17
DOI : 10.5389/KSAE.2010.52.2.011
For the reasonable analysis of design problems for agricultural facilities, considered the reinforcing effect of thin-wall. The most of agricultural structure is constructed small scale and have many purposes. Thus it has been designed temporary rather than permanent structure, and has relatively large slenderness ratio, small section and semi-rigid condition. Therefore many agricultural facilities are consist of relatively strong frame with weak wall at the viewpoint of stiffness and have not been reflected in the design. But the tension field influences to collapse of structure have already known. Therefore, we need quantification the effect of tension field at structural analysis. In this study, present the method of quantification the effect of tension field that came out thin-plate surrounded by high stiffness frame. The numerical results show that the effect of tension field effect for thin-wall is about 5% of the sectional area of frame in study agricultural facilities.
Characteristic of Resilient Modulus and Unconfined Compressive Strength for Recycled Materials blend with Cement Kiln Dust
Son, Young-Hwan ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 19~25
DOI : 10.5389/KSAE.2010.52.2.019
This study was conducted to determine the resilient modulus (Mr) and the unconfined compressive strength (UCS) of two recycled roadway materials such as recycled pavement material (RPM) and road surface gravel (RSG) with or without cement kiln dust (CKD). The recycled materials were blended with two CKD contents (5, 10 %) and 28 day curing time. Mr and UCS tests were also conducted after 10cycles of freezing and thawing to asses the impact of freeze-thaw cycling. Mr was determined conducting by the laboratory test method described by NCHRP 1-28A. Stabilized RPM and RSG had a modulus and a strength higher than unstabilized RPM and RSG. Mr and UCS of RPM and RSG mixed with CKD increased with increasing CKD content. The results indicated that the addition of CKD could be improved the strength and the stiffness of RPM and RSG. Therefore, RPM, RSG and CKD could be used as an effective materials in the reconstruction of roads.
Development Model for Estimating Critical Path Probability of Element Path in PERT
Youn, Deuk-No ; Kim, Tae-Gon ; Han, Yi-Cheol ; Lee, Jeong-Jae ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 27~34
DOI : 10.5389/KSAE.2010.52.2.027
The PERT is one form of probabilistic network and can have many critical paths in the concept of each work has dispersed complete time. Here we propose two operators to estimate the probabilistic complete time about serial and parallel connections, and in each junction node, probability of critical path is estimated by new operator. Then we compare the estimated results with robability of critical path with deterministic CPM and Monte Carlo simulation (MCS). Our results show that all paths in PERT can be critical path, and proposed operators are efficient and accurate probabilistic calculators compare MCS result.
Implementation of System for a Ubiquitous Farming-diary
Lee, Yong-Woong ; Cho, Jong-Sik ; Ju, Jong-Gil ; Shin, Chang-Sun ; Yoe, Hyun ; Lee, Jong-Hyun ; Sin, Han-Ho ; Yum, Chang-Yeol ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 35~42
DOI : 10.5389/KSAE.2010.52.2.035
In this paper, we propose a ubiquitous Farming Diary System which can support the easy and reliable recording of a farming diary for the certificate on environment-friendly agricultural products by using the USN(Ubiquitous Sensor Network) technologies. By using growth-related data, the system can also control farming facilities remotely and automatically. To achieve this goal, the UFDS(Ubiquitous Farming Diary System) is consisted with 3 layers. The first `physical layer` can collect data from sensors, cameras and facilities then controls the growth environment based on the analyzed information. The second `Middle layer` can process and store the data from `physical layer` to sensor manager, image manager, control manager and diary manager separately. The third `application layer` can provide growth-related services to users through various applications. The UFDS can recording grow history information automatically and Easily. Besides, the system can make an accurate and reliable farming diary with multimedia information such as motion and sound. Furthermore, environmental information such as temperature, humidity, luminance and soil conditions (soil temperature, soil humidity, soil EC) can be monitored in real-time and the facilities managed in remote sites.
Characteristics of Vertical Stress Distribution in Sandy Soil According to the Relative Compaction and Composition of the Soil Layer
Nam, Hyo-Seok ; Lee, Sang-Ho ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 43~50
DOI : 10.5389/KSAE.2010.52.2.043
This study was carried out to evaluate the vertical stress properties in sandy soil according to changes of foundation condition in soil bin compacted three layers. The following conclusions and comparisons have been made based on careful analysis from theoretical and experimental methods. : When sandy soil subjected to circular uniform load, the vertical stress increments (
) was increased as load increasing, the maximum values of
was achieved at the point loading axis, and
was not shown over at a distance of three times of loading plate width (B). The vertical stress increments were achieved largely at 80 % relative compaction (Rc) compared to 95 % relative compaction due to stress concentration in sandy soil. When sandy soil subjected to circular uniform load, the
differences between theoretical and experimental values as load increased were more increased and its maximum differences were achieved at stress axis. When gravel surface macadamized over sandy soil subjected to load, the
was concentrated to load axis as load increasing, so that macadamization will be decreased load transmission.
Evaluation of Resilient Modulus Models for Recycled Materials
Son, Young-Hwan ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 51~57
DOI : 10.5389/KSAE.2010.52.2.051
Many models have been used to represent the effects of confining stress, bulk stress, and shear stress on the value of the resilient modulus (Mr). This study was conducted to estimate Mr of the recycled materials such as recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP) through the repeated load cyclic test. Also, two models were applied to estimation of Mr for comparing between measured Mr values and predicted Mr values. The first model (A-model) can provide a quick and easy estimation of the Mr based on the bulk stress, while the second model (N-model) includes not only the bulk stress but also the shear stress. Statistical analysis indicated that all results using the both of models are significant at a 95 % confidence level. Therefore, the both of models could be used as an effective prediction model of Mr for RCA and RAP. Especially, the Model 2 including the parameters of the bulk stress and the shear stress could give more reliable estimation at the high range of Mr values.
Characteristics of Reservoir Behavior According to Establishment Range of Waterproof Mat During Overflow
Kim, Young-Ik ; Lee, Ik-Sang ; Choi, Don-Hwan ; Im, Eun-Sang ; Kim, Yong-Seong ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 59~66
DOI : 10.5389/KSAE.2010.52.2.059
This study was performed to develop the embankment protection method that can reduce demage by prevention of embankment loss and collapse from overflow due to heavy rain and flood. For overflow test, model dam was prepared and embankment behaviors were monitored with the established piezometer and strain meter during overflow. As a result of overflow test for model dam, in case of embankment without waterproof mat, the lower end of embankment was collapsed within 40 seconds after beginning of overflow. On the other hand, in case of embankment with waterproof mat, embankment collapse didn`t occurred during overflow. Accordingly, establishment of waterproof mat for embankment showed that be absolutely effective for the embankment protection during overflow in reservoir. Also, it showed that the minimum establishment range of waterproof mat to prevent embankment collapse in reservoir is from maximum storage level to the lower end of embankment.
Heat Loss Audit and Assessment of the Greenhouses Using Infrared Thermal Image Analysis
Moon, Jong-Pil ; Yun, Nam-Kyu ; Lee, Sung-Hyoun ; Kim, Hak-Joo ; Lee, Su-Jang ; Kim, Young-Hwa ;
Journal of The Korean Society of Agricultural Engineers, volume 52, issue 2, 2010, Pages 67~73
DOI : 10.5389/KSAE.2010.52.2.067
Unlike Urban building, horticultural facilities has a lot of heat loss through plastic or glass covering material which could be much influential to growing plant and consuming energy for heating greenhouse. In many cases, heat loss from a break of cover, a gap of joint sealing, the entrance to greenhouse and windows for ventilation are the main factors considered in calculating the heating load for horticultural facilities. however the normal observation through human eye and digital camera could not recognize where the heat loss occurred. but the infrared thermal image camera with detecting thermal difference could be very effective for noticing heat loss by analyzing infrared thermal image. In this study, greenhouse structure, covering material, internal and external provisions for Horticultural facilities were surveyed in different sites and Infrared thermal camera shooting and image analysis were performed for auditing heat loss from cultivation facilities The results from this study were that unexpected heat loss had been noticed in 7 representative cases of greenhouse such as side wall covered with single or double plastic, and the joint of horizontal thermal curtain, roof without horizontal thermal curtain, entrance to greenhouse, windows for ventilation. the most important factors for keeping heat energy were whether the horizontal thermal curtain with multifold thermal material was installed or not. The internal or external covering using multifold thermal curtain proved to be the most effective ways to keep heat energy from losing through heat transmission, heat radiation. from inside to outside the horticultural facilities.