This paper introduces a new approach of firefly algorithm based on opposition-based learning （OBFA） to enhance the global search ability of the original algorithm. The new algorithm employs opposition based learning...This paper introduces a new approach of firefly algorithm based on opposition-based learning （OBFA） to enhance the global search ability of the original algorithm. The new algorithm employs opposition based learning concept to generate initial population and also updating agents’ positions. The proposed OBFA is applied for minimization of the factor of safety and search for critical failure surface in slope stability analysis. The numerical experiments demonstrate the effectiveness and robustness of the new algorithm.展开更多
Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is ...Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.展开更多
This paper deals with the economically optimized design and sensitivity of two of the most widely used systems in geotechnical engineering: spread footing and retaining wall. Several recent advanced optimization metho...This paper deals with the economically optimized design and sensitivity of two of the most widely used systems in geotechnical engineering: spread footing and retaining wall. Several recent advanced optimization methods have been developed, but very few of these methods have been applied to geotechnical problems. The current research develops a modified particle swarm optimization (MPSO) approach to obtain the optimum design of spread footing and retaining wall. The algorithm handles the problem-specific constraints using a penalty function approach. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the structures. To verify the effectiveness and robustness of the proposed algorithm, three case studies of spread footing and retaining wall are illustrated. Comparison of the results of the present method, standard PSO, and other selected methods employed in previous studies shows the reliability and accuracy of the algorithm. Moreover, the parametric performance is investigated in order to examine the effect of relevant variables on the optimum design of the footing and the retaining structure utilizing the proposed method.展开更多
Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as t...Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as the only income source for low-income farmers in poorer countries,which produce a considerable portion of the agricultural products in some regions of the world.In this research,two novel layouts of a semipermanent sprinkler irrigation system,namely,clock hand(CH)and corner pivot(CP)lateral designs,were designed for a lighter irrigation system to lower the cost requirement.The new techniques were based on a quadrant/full circle movement pattern of manually pivoting laterals,with no/shorter main pipe requirements,which causes a higher system efficiency.These retrofitted layouts were examined in different farms with areas of 0.20 hm^(2),0.81 hm^(2),1.62 hm^(2),and 3.24 hm^(2) in Guangxi,China.This study introduced,analyzed,and compared the layouts with the widespread traditional split lateral method on technical planning,components,implementation,operation details,size optimization,performance evaluation,and economic advantages.In comparison with the traditional system,CH and CP were found to be more user-friendly and cost-effective but slightly complicated in design with higher required manual work.The results revealed a distribution uniformity(LQDU)of 81.0%to 84.0%via the catch can method,lower capital costs(35.0%-45.0%),and lower annual expenses(6.5%-9.8%)for CP and CH,respectively,compared to the split lateral method.The 0.81 hm^(2) and 1.62 hm^(2) farms were found to be the optimum farm sizes for implementation of the new methods for a 25-year project time horizon.The outcomes of this experimental work can encourage small farm owners with limited capital to apply pressurized systems for efficient irrigation and water resource sustainability.展开更多
文摘This paper introduces a new approach of firefly algorithm based on opposition-based learning （OBFA） to enhance the global search ability of the original algorithm. The new algorithm employs opposition based learning concept to generate initial population and also updating agents’ positions. The proposed OBFA is applied for minimization of the factor of safety and search for critical failure surface in slope stability analysis. The numerical experiments demonstrate the effectiveness and robustness of the new algorithm.
文摘Electrical capacitance volume tomography(ECVT) is a recently-developed technique for real-time,non-invasive 3D monitoring of processes involving materials with strong contrasts in dielectric permittivity.This work is first application of the method to visualization of water flow in soil.We describe the principles behind the method,and then demonstrate its use with a simple laboratory infiltration experiment.32 ECVT sensors were installed on the sides of an empty PVC column.Water was poured into the column at a constant rate,and ECVT data were collected every second.The column was then packed with dry sand and again supplied with water at a constant rate with data collected every second.Data were analyzed to give bulk average water contents,which proved consistent with the water supply rates.Data were also analyzed to give 3D images(216 voxels) allowing visualization of the water distribution during the experiments.Result of this work shows that water infiltration into the soil,wall flow,progress of the unstable wetting front and the final water distribution are clearly visible.
文摘This paper deals with the economically optimized design and sensitivity of two of the most widely used systems in geotechnical engineering: spread footing and retaining wall. Several recent advanced optimization methods have been developed, but very few of these methods have been applied to geotechnical problems. The current research develops a modified particle swarm optimization (MPSO) approach to obtain the optimum design of spread footing and retaining wall. The algorithm handles the problem-specific constraints using a penalty function approach. The optimization procedure controls all geotechnical and structural design constraints while reducing the overall cost of the structures. To verify the effectiveness and robustness of the proposed algorithm, three case studies of spread footing and retaining wall are illustrated. Comparison of the results of the present method, standard PSO, and other selected methods employed in previous studies shows the reliability and accuracy of the algorithm. Moreover, the parametric performance is investigated in order to examine the effect of relevant variables on the optimum design of the footing and the retaining structure utilizing the proposed method.
基金This work was financially supported by the Natural Science Foundation of China(Grant No.52150410408,No.41761048,No.42067002)the Guangxi Science and Technology Program(Grant No.G.K.AA20302020-2).
文摘Pressurized irrigation systems are economically justifiable for medium-to large-scale farms,while fewer choices are available for smallholders.The current research work provides additional options for small plots,as the only income source for low-income farmers in poorer countries,which produce a considerable portion of the agricultural products in some regions of the world.In this research,two novel layouts of a semipermanent sprinkler irrigation system,namely,clock hand(CH)and corner pivot(CP)lateral designs,were designed for a lighter irrigation system to lower the cost requirement.The new techniques were based on a quadrant/full circle movement pattern of manually pivoting laterals,with no/shorter main pipe requirements,which causes a higher system efficiency.These retrofitted layouts were examined in different farms with areas of 0.20 hm^(2),0.81 hm^(2),1.62 hm^(2),and 3.24 hm^(2) in Guangxi,China.This study introduced,analyzed,and compared the layouts with the widespread traditional split lateral method on technical planning,components,implementation,operation details,size optimization,performance evaluation,and economic advantages.In comparison with the traditional system,CH and CP were found to be more user-friendly and cost-effective but slightly complicated in design with higher required manual work.The results revealed a distribution uniformity(LQDU)of 81.0%to 84.0%via the catch can method,lower capital costs(35.0%-45.0%),and lower annual expenses(6.5%-9.8%)for CP and CH,respectively,compared to the split lateral method.The 0.81 hm^(2) and 1.62 hm^(2) farms were found to be the optimum farm sizes for implementation of the new methods for a 25-year project time horizon.The outcomes of this experimental work can encourage small farm owners with limited capital to apply pressurized systems for efficient irrigation and water resource sustainability.
