Many existing product family design methods assume a given platform, However, it is not an in-tuitive task to select the platform and unique variable within a product family. Meanwhile, most approaches are single-plat...Many existing product family design methods assume a given platform, However, it is not an in-tuitive task to select the platform and unique variable within a product family. Meanwhile, most approaches are single-platform methods, in which design variables are either shared across all product variants or not at all. While in multiple-platform design, platform variables can have special value with regard to a subset of product variants within the product family, and offer opportunities for superior overall design. An information theoretical approach incorporating fuzzy clustering and Shannon's entropy was proposed for platform variables selection in multiple-platform product family. A 2-level chromosome genetic algorithm (2LCGA) was proposed and developed for optimizing the corresponding product family in a single stage, simultaneously determining the optimal settings for the product platform and unique variables. The single-stage approach can yield im-provements in the overall performance of the product family compared with two-stage approaches, in which the first stage involves determining the best settings for the platform and values of unique variables are found for each product in the second stage. An example of design of a family of universal motors was used to verify the proposed method.展开更多
The ongoing need for better fuel economy and lower exhaust pollution of vehicles has increased the employment of electric power steering(EPS)in automotives.Optimal design of EPS for a product family reduces the develo...The ongoing need for better fuel economy and lower exhaust pollution of vehicles has increased the employment of electric power steering(EPS)in automotives.Optimal design of EPS for a product family reduces the development and fabrication costs significantly.In this paper,the TOPSIS method along with the NSGA-Ⅱis employed to find an optimum family of EPS for an automotive platform.A multi-objective optimization problem is defined considering road feel,steering portability,RMS of Ackerman error,and product family penalty function(PFPF)as the conflicting objective functions.The results for the single objective optimization problems and the ones for the multi-objective optimization problem,as well as two suggested trade-off design points are presented,compared and discussed.For the two suggested points,performance at one objective function is deteriorated by about 1%,while the commonality is increased by 20%–40%,which shows the effectiveness of the proposed method in first finding the non-dominated design points and then selecting the trade-off among the obtained points.The results indicate that the obtained trade-off points have superior performance within the product family with maximum number of common parts.展开更多
Because of the powerful mapping ability, back propagation neural network (BP-NN) has been employed in computer-aided product design (CAPD) to establish the property prediction model. The backward problem in CAPD is to...Because of the powerful mapping ability, back propagation neural network (BP-NN) has been employed in computer-aided product design (CAPD) to establish the property prediction model. The backward problem in CAPD is to search for the appropriate structure or composition of the product with desired property, which is an optimization problem. In this paper, a global optimization method of using the a BB algorithm to solve the backward problem is presented. In particular, a convex lower bounding function is constructed for the objective function formulated with BP-NN model, and the calculation of the key parameter a is implemented by recurring to the interval Hessian matrix of the objective function. Two case studies involving the design of dopamine β-hydroxylase (DβH) inhibitors and linear low density polyethylene (LLDPE) nano composites are investigated using the proposed method.展开更多
Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels (gaso...Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels (gasoline, diesel etc.). Selectivity of Fischer-Tropsch hydrocarbon product (green fuel) is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 (K), P = 3-10 (bar), H2/CO = 1-2 and space velocity = 4500 (l/h) were the reactor conditions. The results of product modeling for methane (CH4), ethane (C2H6), ethylene (C2H4) and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.展开更多
The modern textile production is driven by order forms, in which continuous and discrete characteristics both exist. Hybrid Petri net (HPN) was selected to build the textile production model that described all operati...The modern textile production is driven by order forms, in which continuous and discrete characteristics both exist. Hybrid Petri net (HPN) was selected to build the textile production model that described all operations in a uniform form, and connected them by discrete places and inhibitor arcs. Based on this structured model, the mathematical programming description was given. In order to take the minimal costs and complete all order forms in due time, genetic algorithm (GA) was used to optimize the production scheduling scheme. Using the data from a textile enterprise, the simulation proves that the proposed method is effective.展开更多
Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product s...Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.展开更多
Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of p...Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of product design. This paper firstly defines concept of product design, then after an analysis of design objectives the author proposes a target system of product design with three subsystems: structural system, functional system, and technical system. Finally, a product design system on Architectural Metal Structure Enterprises is developed and used in light of the great consumption of material resources in Metal Structure Enterprises. The system has got an obvious effect on improving comprehensive optimal using rate of material resources of enterprises, reducing design cycle, improving management of enterprises.展开更多
In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. T...In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).展开更多
Cell disruption focuses on obtaining a desired bioproduct within a cell, and it is the cell wall that must be disrupted to allow access to the contents of the cell. In animal cells, the plasma membrane is the only bar...Cell disruption focuses on obtaining a desired bioproduct within a cell, and it is the cell wall that must be disrupted to allow access to the contents of the cell. In animal cells, the plasma membrane is the only barrier separating cell contents from the environment. Sound waves from sonication, a mechanical technique for cell disintegration, have been used to disrupt as well as to aggregate cells as a step towards purification of a desired bioproduct. In the present study, an improved sonication process for the high yield of Newcastle disease virus (NDV) propagated in tissue culture was described. DF-I cell was cultured in 25cm^2 T flask. When cells were about 80% confluent, a lentogenic strain of NDV (F strain) was used to infect the cell monolayer. With evident cytopathic effect, cells were subjected to cycles of freeze-thaw before sonicating with varying combinations of amplitude, temperature and time. Cells were sonicated using a water bath Sonicator, Jac Ultrasonic 1505 JEIO TECH 4 KHz. From ANOVA analysis, a significant interaction between sonication time and amplitude was observed. This also corresponds to the highest F value observed.展开更多
Virtual dynamic optimization design can avoid the repeated process from de-sign to trial-manufacture and test.The designer can analyze and optimize the productstructures in virtual visualization environment.The design...Virtual dynamic optimization design can avoid the repeated process from de-sign to trial-manufacture and test.The designer can analyze and optimize the productstructures in virtual visualization environment.The design cycle is shortened and the costis reduced.The paper analyzed the peculiarity of virtual optimization design,and put for-wards the thought and flow to implement virtual optimization design.The example to opti-mize the internal grinder was studied via establishing precise finite element model,modi-fying the layout of Stiffened Plates and designing parameters of the worktable,and usingthe technology of modal frequency revision and the technology of multiple tuned damper.The result of optimization design compared the new grinder with the original grinder showsthat the entire machine's first orders natural frequency is enhanced by 17%,and the re-sponse displacement of the grinding-head has dropped by 28% under the first order natu-ral frequency and by 41% under second order natural frequency.Finally,the dynamic per-formance of the internal grinder was optimized.展开更多
Even though Saudi Arabia is the world's largest producer and exporter of petroleum and petroleum based products, it is also blessed with high potential of renewable energy sources like solar and wind. Untapped wind a...Even though Saudi Arabia is the world's largest producer and exporter of petroleum and petroleum based products, it is also blessed with high potential of renewable energy sources like solar and wind. Untapped wind and solar energy sources, which are abundant throughout the kingdom, can be connected and optimally integrated into the grid through the use of smart grid technologies and the expansion of transmission facilities. Smart grid is an auto-balancing, self-monitoring power grid that accepts power from any source of fuel like oil, sun or wind and delivers electricity from suppliers to consumers. It helps to control the use of appliances in order to save energy, reduces cost and increase reliability. This paper describes the attributes of a smart grid and how these act as driving force to modernize the electrical power grid. The necessity of conservation of oil in Saudi Arabia is argued. Moreover, the vast availability of renewable energy sources like solar and wind in Saudi Arabia and advantages in utilizing these sources through smart grid technologies are advocated in this paper.展开更多
Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analys...Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.展开更多
Expanded snacks made up of corn, wheat and rice is very popular because of their texture. Sorghum is one of the important cereals, which is not so far studied well for extrusion processing. Due to presence of high amo...Expanded snacks made up of corn, wheat and rice is very popular because of their texture. Sorghum is one of the important cereals, which is not so far studied well for extrusion processing. Due to presence of high amount of starch (56%-73%): sorghum could be the good candidate for manufacturing of expanded snacks. The extruded products obtained using extrusion conditions such as feed moisture content (12%-16%), die temperature (150-190℃), screw speed (150-210 rpm) and feed rate (50-70 g min1) are further characterized by analyzing bulk density, expansion ratio, water absorption index (WAI), water solubility index (WSI), textural properties, color and sensory evaluation. Increase in feed moisture content resulted in extrudates with gradual increase in density, WAI and hardness and decrease in expansion, WSI, crispness and whiteness. Higher barrel temperature reduced the extrudate expansion, bulk density and hardness and increased the WSI and crispness of the extrudates. The most acceptable product is obtained using response surface methodology (RSM).展开更多
Based on flow loss, a new automatic pipe-routing algorithm is proposed for electromechanical product in 3D space, which consists of pre-processing and optimization search. Utilizing chaos theory, a chaos grid preproce...Based on flow loss, a new automatic pipe-routing algorithm is proposed for electromechanical product in 3D space, which consists of pre-processing and optimization search. Utilizing chaos theory, a chaos grid preprocessing model (CGPM) is established to efficiently pick up the solution space and reduce the search range in the pre-processing, which simplifies the optimization search. A modified particle swarm optimization (PSO) algorithm is presented to seek for an approximate optimal trajectory in the solution space in the optimization search based on standard PSO algorithm and migration characters of people. The comparison of experiments and analysis results shows that the modified PSO algorithm is capable of preventing prematurity effectively and searching for the optimal trajectory more efficiently. Theoretical analysis proves that the modified PSO algorithm converges at global optimum. The examples show that the automatic pipe-routing algorithm based on flow loss is effective and practical for eleetromechanieal product.展开更多
The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It's known as th...The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It's known as the high capacity of cation exchange of the natural Cuban clinoptilolite, which contributes to reducing nutrient losses, such as ammonia, and keeping the potassium and phosphorus cations available. Extensive tests were done on the field with the objective to evaluate the agronomic effect of incorporating this mineral in fertilizer. The results obtained in this experiment contributed to almost all Cuban chemical fertilizers, which has been incorporated around 15%-20% of natural zeolite clinoptilolite in its composition by Cuban agriculture consumes, reducing the chemical carriers of the fertilizers and decreasing the contamination of the environment. Also this mineral contributes for increases in agricultural income more than 15% in all cases; additionally, a trend can be observed towards gradual recovery of some soil fertility indicators, in which the chemical fertilizers with Fertcel was applied.展开更多
Under the background of China's rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization fo...Under the background of China's rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization for the Chinese government. Taking the Beijing-Tianjin-Hebei(BTH) and Boswash as study area, we mapped the subpixel-level impervious surface coverage of the BTH and Boswash, respectively, from 1972 to 2011. Further, landscape metrics, gravitational model and spatial analysis were used to analyze the differences of the spatial structures between the BTH and Boswash. The results showed that(1) the area of the impervious surface increased rapidly in the BTH, while those remained stable in the Boswash.(2) The spatial structure of the BTH experienced different periods including isolated cities stage, dual-core cities stage, group cities stage and network-style cities stage, while those of the Boswash was more stable, and its spatial pattern showed a "point-axis" structure.(3) The spatial pattern of high-high assembling regions of the impervious surface exhibited a "standing pancake" feature in the BTH, while those showed a "multi-center, local aggregation and global discrete" feature in the Boswash.(4) All the percentages of the impervious surface of ecological, living, and production land of the BTH were higher than those of the Boswash. At last, from the perspective of space optimization of urban agglomeration, the development proposals for the BTH were proposed.展开更多
Complicated mechanical products normally consist of multi-parameter mechanisms.The couplings between two tmechanisms are either strong or weak.The traditional optimal design methods cannot meet the requirements of opt...Complicated mechanical products normally consist of multi-parameter mechanisms.The couplings between two tmechanisms are either strong or weak.The traditional optimal design methods cannot meet the requirements of optimal structural design of the complicated multi-parameter mechanical products.On the basis of analyzing the optimal design methods and the data mining principles,an improved iterative dichotomizer 3(ID3) algorithm is hereby put forth to bring out an optimal design information model integrated with the data mining technology as well as an optimal structural design system of complicated mechanical products based on the data mining principles.The system is demonstrated by the optimal structural design of the mainframe of the full face rock tunnel boring machine(TBM).An example shows that the data mining technology has fully tackled the issues of the optimal structural design of complicated mechanical products.展开更多
After reviewing the literature and methodology-related issues within the field of product family design, a deficiency in the current design and development of product family is pointed out. The concept of hierarchical...After reviewing the literature and methodology-related issues within the field of product family design, a deficiency in the current design and development of product family is pointed out. The concept of hierarchical associated design is proposed in this article, according to the deficiency~ and the methods and models for realizing the notion above are described. A two-dimensional analytical model is constructed based on the composing levels and developing processes of product family. The optimization models to hierarchical associated design problems are grouped into two categories: overall-local and key-subordinate. The algorithms of the models are discussed in this paper展开更多
基金the National Natural Science Founda-tion of China (No. 70471022)Joint Research Scheme ofthe National Natural Science Foundation of China andthe Hong Kong Research Grant Council (No. 70418013)
文摘Many existing product family design methods assume a given platform, However, it is not an in-tuitive task to select the platform and unique variable within a product family. Meanwhile, most approaches are single-platform methods, in which design variables are either shared across all product variants or not at all. While in multiple-platform design, platform variables can have special value with regard to a subset of product variants within the product family, and offer opportunities for superior overall design. An information theoretical approach incorporating fuzzy clustering and Shannon's entropy was proposed for platform variables selection in multiple-platform product family. A 2-level chromosome genetic algorithm (2LCGA) was proposed and developed for optimizing the corresponding product family in a single stage, simultaneously determining the optimal settings for the product platform and unique variables. The single-stage approach can yield im-provements in the overall performance of the product family compared with two-stage approaches, in which the first stage involves determining the best settings for the platform and values of unique variables are found for each product in the second stage. An example of design of a family of universal motors was used to verify the proposed method.
文摘The ongoing need for better fuel economy and lower exhaust pollution of vehicles has increased the employment of electric power steering(EPS)in automotives.Optimal design of EPS for a product family reduces the development and fabrication costs significantly.In this paper,the TOPSIS method along with the NSGA-Ⅱis employed to find an optimum family of EPS for an automotive platform.A multi-objective optimization problem is defined considering road feel,steering portability,RMS of Ackerman error,and product family penalty function(PFPF)as the conflicting objective functions.The results for the single objective optimization problems and the ones for the multi-objective optimization problem,as well as two suggested trade-off design points are presented,compared and discussed.For the two suggested points,performance at one objective function is deteriorated by about 1%,while the commonality is increased by 20%–40%,which shows the effectiveness of the proposed method in first finding the non-dominated design points and then selecting the trade-off among the obtained points.The results indicate that the obtained trade-off points have superior performance within the product family with maximum number of common parts.
文摘Because of the powerful mapping ability, back propagation neural network (BP-NN) has been employed in computer-aided product design (CAPD) to establish the property prediction model. The backward problem in CAPD is to search for the appropriate structure or composition of the product with desired property, which is an optimization problem. In this paper, a global optimization method of using the a BB algorithm to solve the backward problem is presented. In particular, a convex lower bounding function is constructed for the objective function formulated with BP-NN model, and the calculation of the key parameter a is implemented by recurring to the interval Hessian matrix of the objective function. Two case studies involving the design of dopamine β-hydroxylase (DβH) inhibitors and linear low density polyethylene (LLDPE) nano composites are investigated using the proposed method.
文摘Increase in greenhouse gases, has made scientists to substitute alternative fuels for fossil fuels. Nowadays, converting biomass into liquid by Fischer-Tropsch synthesis is a major concern for alternative fuels (gasoline, diesel etc.). Selectivity of Fischer-Tropsch hydrocarbon product (green fuel) is an important issue. In this study, the experimental data has been obtained from three factors; temperature, H2/CO ratio and pressure in the fixed bed micro reactor. T = 543-618 (K), P = 3-10 (bar), H2/CO = 1-2 and space velocity = 4500 (l/h) were the reactor conditions. The results of product modeling for methane (CH4), ethane (C2H6), ethylene (C2H4) and CO conversion with experimental data were compared. The effective parameters and the interaction between them were investigated in the model. H2/CO ratio and pressure and interaction between pressure and H2/CO in ethane selectivity model and CO conversion and interaction between temperature and H2/CO ratio in methane selectivity model and ethylene gave the best results. To determine the optimal conditions for light hydrocarbons, ANOVA and RSM were employed. Finally, products optimization was done and results were concluded.
基金National Natural Science Foundation of China(No. 60873003)
文摘The modern textile production is driven by order forms, in which continuous and discrete characteristics both exist. Hybrid Petri net (HPN) was selected to build the textile production model that described all operations in a uniform form, and connected them by discrete places and inhibitor arcs. Based on this structured model, the mathematical programming description was given. In order to take the minimal costs and complete all order forms in due time, genetic algorithm (GA) was used to optimize the production scheduling scheme. Using the data from a textile enterprise, the simulation proves that the proposed method is effective.
文摘Product system design is a mature concept in western developed countries. It has been applied in war industry during the last century. However,up until now,functional combination is still the main method for product system de-sign in China. Therefore,in terms of a concept of product generation and product interaction we are in a weak position compared with the requirements of global markets. Today,the idea of serial product design has attracted much attention in the design field and the definition of product generation as well as its parameters has already become the standard in serial product designs. Although the design of a large-scale NC machine tool is complicated,it can be further optimized by the precise exercise of object design by placing the concept of platform establishment firmly into serial product de-sign. The essence of a serial product design has been demonstrated by the design process of a large-scale NC machine tool.
基金Foundation item: Funded by China 863 R&D Program(No: 2002AA414080)
文摘Product design plays a decisive role in material resource consumption in manufacturing systems. So it is significant to study optimal utilization of material resources of manufacturing system from the perspective of product design. This paper firstly defines concept of product design, then after an analysis of design objectives the author proposes a target system of product design with three subsystems: structural system, functional system, and technical system. Finally, a product design system on Architectural Metal Structure Enterprises is developed and used in light of the great consumption of material resources in Metal Structure Enterprises. The system has got an obvious effect on improving comprehensive optimal using rate of material resources of enterprises, reducing design cycle, improving management of enterprises.
基金support and help of many individuals in the SASTRA University
文摘In a manufacturing industry, mixed model assembly line(MMAL) is preferred in order to meet the variety in product demand. MMAL balancing helps in assembling products with similar characteristics in a random fashion. The objective of this work aims in reducing the number of workstations, work load index between stations and within each station. As manual contribution of workers in final assembly line is more, ergonomics is taken as an additional objective function. Ergonomic risk level of a workstation is evaluated using a parameter called accumulated risk posture(ARP), which is calculated using rapid upper limb assessment(RULA) check sheet. This work is based on the case study of an MMAL problem in Rane(Madras) Ltd.(India), in which a problem based genetic algorithm(GA) has been proposed to minimize the mentioned objectives. The working of the genetic operators such as selection, crossover and mutation has been modified with respect to the addressed MMAL problem. The results show that there is a significant impact over productivity and the process time of the final assembled product, i.e., the rate of production is increased by 39.5% and the assembly time for one particular model is reduced to 13 min from existing 18 min. Also, the space required using the proposed assembly line is only 200 m2 against existing 350 m2. Further, the algorithm helps in reducing workers fatigue(i.e., ergonomic friendly).
文摘Cell disruption focuses on obtaining a desired bioproduct within a cell, and it is the cell wall that must be disrupted to allow access to the contents of the cell. In animal cells, the plasma membrane is the only barrier separating cell contents from the environment. Sound waves from sonication, a mechanical technique for cell disintegration, have been used to disrupt as well as to aggregate cells as a step towards purification of a desired bioproduct. In the present study, an improved sonication process for the high yield of Newcastle disease virus (NDV) propagated in tissue culture was described. DF-I cell was cultured in 25cm^2 T flask. When cells were about 80% confluent, a lentogenic strain of NDV (F strain) was used to infect the cell monolayer. With evident cytopathic effect, cells were subjected to cycles of freeze-thaw before sonicating with varying combinations of amplitude, temperature and time. Cells were sonicated using a water bath Sonicator, Jac Ultrasonic 1505 JEIO TECH 4 KHz. From ANOVA analysis, a significant interaction between sonication time and amplitude was observed. This also corresponds to the highest F value observed.
基金Supported by the National Natural Science Foundation of China(50375026)
文摘Virtual dynamic optimization design can avoid the repeated process from de-sign to trial-manufacture and test.The designer can analyze and optimize the productstructures in virtual visualization environment.The design cycle is shortened and the costis reduced.The paper analyzed the peculiarity of virtual optimization design,and put for-wards the thought and flow to implement virtual optimization design.The example to opti-mize the internal grinder was studied via establishing precise finite element model,modi-fying the layout of Stiffened Plates and designing parameters of the worktable,and usingthe technology of modal frequency revision and the technology of multiple tuned damper.The result of optimization design compared the new grinder with the original grinder showsthat the entire machine's first orders natural frequency is enhanced by 17%,and the re-sponse displacement of the grinding-head has dropped by 28% under the first order natu-ral frequency and by 41% under second order natural frequency.Finally,the dynamic per-formance of the internal grinder was optimized.
文摘Even though Saudi Arabia is the world's largest producer and exporter of petroleum and petroleum based products, it is also blessed with high potential of renewable energy sources like solar and wind. Untapped wind and solar energy sources, which are abundant throughout the kingdom, can be connected and optimally integrated into the grid through the use of smart grid technologies and the expansion of transmission facilities. Smart grid is an auto-balancing, self-monitoring power grid that accepts power from any source of fuel like oil, sun or wind and delivers electricity from suppliers to consumers. It helps to control the use of appliances in order to save energy, reduces cost and increase reliability. This paper describes the attributes of a smart grid and how these act as driving force to modernize the electrical power grid. The necessity of conservation of oil in Saudi Arabia is argued. Moreover, the vast availability of renewable energy sources like solar and wind in Saudi Arabia and advantages in utilizing these sources through smart grid technologies are advocated in this paper.
基金Supported by the National Natural Science Foundation of China(61590924,61673273,61521063)
文摘Exergy indicates the maximal energy that can do work effectively. Different from optimization of product quality or calculation of generic energy conservation in most previous studies, the application of exergy analysis and exergy cost optimization in petrochemical industry is of great economic and environmental significance. Based on the main fractionator in Jiujiang Petrochemical Complex No. 2 FCCU, an enhanced exergy cost optimization under different operating conditions by adjusting set points of temperature and valves opening degree for flow control is studied in this paper in order to reduce exergy cost and improve the quality of energy. A steadystate optimization algorithm to enhance exergy availability and an objective function comprehensively considering exergy loss are proposed. On the basis of ensuring the quality of petroleum products, the economic benefits can be improved by optimizing the controllable variables due to the fact that exergy cost is decreased.
文摘Expanded snacks made up of corn, wheat and rice is very popular because of their texture. Sorghum is one of the important cereals, which is not so far studied well for extrusion processing. Due to presence of high amount of starch (56%-73%): sorghum could be the good candidate for manufacturing of expanded snacks. The extruded products obtained using extrusion conditions such as feed moisture content (12%-16%), die temperature (150-190℃), screw speed (150-210 rpm) and feed rate (50-70 g min1) are further characterized by analyzing bulk density, expansion ratio, water absorption index (WAI), water solubility index (WSI), textural properties, color and sensory evaluation. Increase in feed moisture content resulted in extrudates with gradual increase in density, WAI and hardness and decrease in expansion, WSI, crispness and whiteness. Higher barrel temperature reduced the extrudate expansion, bulk density and hardness and increased the WSI and crispness of the extrudates. The most acceptable product is obtained using response surface methodology (RSM).
文摘Based on flow loss, a new automatic pipe-routing algorithm is proposed for electromechanical product in 3D space, which consists of pre-processing and optimization search. Utilizing chaos theory, a chaos grid preprocessing model (CGPM) is established to efficiently pick up the solution space and reduce the search range in the pre-processing, which simplifies the optimization search. A modified particle swarm optimization (PSO) algorithm is presented to seek for an approximate optimal trajectory in the solution space in the optimization search based on standard PSO algorithm and migration characters of people. The comparison of experiments and analysis results shows that the modified PSO algorithm is capable of preventing prematurity effectively and searching for the optimal trajectory more efficiently. Theoretical analysis proves that the modified PSO algorithm converges at global optimum. The examples show that the automatic pipe-routing algorithm based on flow loss is effective and practical for eleetromechanieal product.
文摘The shortages of chemical fertilizers in Cuba in 90s caused the introduction of different research results obtained on this time for the implementation of natural zeolites in the fertilizer industry. It's known as the high capacity of cation exchange of the natural Cuban clinoptilolite, which contributes to reducing nutrient losses, such as ammonia, and keeping the potassium and phosphorus cations available. Extensive tests were done on the field with the objective to evaluate the agronomic effect of incorporating this mineral in fertilizer. The results obtained in this experiment contributed to almost all Cuban chemical fertilizers, which has been incorporated around 15%-20% of natural zeolite clinoptilolite in its composition by Cuban agriculture consumes, reducing the chemical carriers of the fertilizers and decreasing the contamination of the environment. Also this mineral contributes for increases in agricultural income more than 15% in all cases; additionally, a trend can be observed towards gradual recovery of some soil fertility indicators, in which the chemical fertilizers with Fertcel was applied.
基金National Natural Science Foundation of China,No.41671339
文摘Under the background of China's rapid urbanization, study on comparative analysis of the spatial structure of urban agglomerations between China and the US can provide the policy proposals of space optimization for the Chinese government. Taking the Beijing-Tianjin-Hebei(BTH) and Boswash as study area, we mapped the subpixel-level impervious surface coverage of the BTH and Boswash, respectively, from 1972 to 2011. Further, landscape metrics, gravitational model and spatial analysis were used to analyze the differences of the spatial structures between the BTH and Boswash. The results showed that(1) the area of the impervious surface increased rapidly in the BTH, while those remained stable in the Boswash.(2) The spatial structure of the BTH experienced different periods including isolated cities stage, dual-core cities stage, group cities stage and network-style cities stage, while those of the Boswash was more stable, and its spatial pattern showed a "point-axis" structure.(3) The spatial pattern of high-high assembling regions of the impervious surface exhibited a "standing pancake" feature in the BTH, while those showed a "multi-center, local aggregation and global discrete" feature in the Boswash.(4) All the percentages of the impervious surface of ecological, living, and production land of the BTH were higher than those of the Boswash. At last, from the perspective of space optimization of urban agglomeration, the development proposals for the BTH were proposed.
基金the 10th Five Years National Key Technical Equipment Development Project of China(No. ZZ02-03-03-01)
文摘Complicated mechanical products normally consist of multi-parameter mechanisms.The couplings between two tmechanisms are either strong or weak.The traditional optimal design methods cannot meet the requirements of optimal structural design of the complicated multi-parameter mechanical products.On the basis of analyzing the optimal design methods and the data mining principles,an improved iterative dichotomizer 3(ID3) algorithm is hereby put forth to bring out an optimal design information model integrated with the data mining technology as well as an optimal structural design system of complicated mechanical products based on the data mining principles.The system is demonstrated by the optimal structural design of the mainframe of the full face rock tunnel boring machine(TBM).An example shows that the data mining technology has fully tackled the issues of the optimal structural design of complicated mechanical products.
文摘After reviewing the literature and methodology-related issues within the field of product family design, a deficiency in the current design and development of product family is pointed out. The concept of hierarchical associated design is proposed in this article, according to the deficiency~ and the methods and models for realizing the notion above are described. A two-dimensional analytical model is constructed based on the composing levels and developing processes of product family. The optimization models to hierarchical associated design problems are grouped into two categories: overall-local and key-subordinate. The algorithms of the models are discussed in this paper