Shared manufacturing is recognized as a new point-to-point manufac-turing mode in the digital era.Shared manufacturing is referred to as a new man-ufacturing mode to realize the dynamic allocation of manufacturing tas...Shared manufacturing is recognized as a new point-to-point manufac-turing mode in the digital era.Shared manufacturing is referred to as a new man-ufacturing mode to realize the dynamic allocation of manufacturing tasks and resources.Compared with the traditional mode,shared manufacturing offers more abundant manufacturing resources and flexible configuration options.This paper proposes a model based on the description of the dynamic allocation of tasks and resources in the shared manufacturing environment,and the characteristics of shared manufacturing resource allocation.The execution of manufacturing tasks,in which candidate manufacturing resources enter or exit at various time nodes,enables the dynamic allocation of manufacturing tasks and resources.Then non-dominated sorting genetic algorithm(NSGA-II)and multi-objective particle swarm optimization(MOPSO)algorithms are designed to solve the model.The optimal parameter settings for the NSGA-II and MOPSO algorithms have been obtained according to the experiments with various population sizes and iteration numbers.In addition,the proposed model’s efficiency,which considers the entries and exits of manufacturing resources in the shared manufacturing environment,is further demonstrated by the overlap between the outputs of the NSGA-II and MOPSO algorithms for optimal resource allocation.展开更多
Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitat...Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitative analysis of the water resources condition in varied environment and prediction of the law of the water resources evolution in the future because year-based time span may best reflect the law of the water resources evolution driven by the nature and human activities in the river basin. This paper advances the theory of annual runoff evolution under natural-artificial dual mode based on the dual mode of the water resources evolution, and the theory is applied for the Wuding River Basin on the middle Yellow River as a case study. A thorough analysis of the precipitation-runoff relationship is made in the case of dynamic variation of ground surface conditions of the Wuding River basin, and the concept of water-soil conservation index area that indicates adoption of various measures for water and soil conservation to reflect ground surface conditions. Furthermore, precipitation-runoff empirical model is developed to reflect dynamic variation of the ground surface conditions of the river basin. The study may lay a solid foundation for the integrated theoretical platform of the law of the water resources evolution in the Yellow River basin and the dual model of the evolution.展开更多
Ecological networks,usually depicting interactions among species,have been recently down-scaled to the individual level,permitting description of patterns of inter-individual resource variation that are usually hinder...Ecological networks,usually depicting interactions among species,have been recently down-scaled to the individual level,permitting description of patterns of inter-individual resource variation that are usually hindered at the species level.Optimal diet theory(ODT)models,applied to prey–predator systems,predict different patterns of nestedness and modularity in the network,depending on the available resources and intra-specific competition.The effect of resource availability on the emergence of networks structures,and ODT framework,has not yet fully been clarified.Here,we analyzed the structural patterns of individual-resource networks in 3 species of Mediterranean salamanders,in relation to changes in prey availability.We used weighted individual-resource network metrics to interpret the observed patterns,according to 3 ODT models.We found significant nestedness recurring in our study system,indicating that both selective and opportunistic individuals occur in the same population.Prey diversity,rather than abundance,was apparently related to inter-individual resource variation and promoted the emergence of significant modularity within all networks.The observed patterns of nestedness and modularity,together with the variation in resource diversity and intra-specific competition,are in agreement with the distinct preferences model of ODT.These findings suggest that in the focal prey–predator systems,individuals were able to perceive changes in prey diversity and to exploit in different ways the variations in composition of available resources,shifting their diet assembly rules accordingly.Our findings also confirm that the use of weighted individual-resource networks,in prey–predator systems,allows to disclose dynamics that are masked at the species or population level.展开更多
Aims Within a habitat of multiple plant species,increased resource availabilities and altered species abundances following disturbances create opportunities for exotic species to successfully establish and subsequentl...Aims Within a habitat of multiple plant species,increased resource availabilities and altered species abundances following disturbances create opportunities for exotic species to successfully establish and subsequently naturalize into its non-native environment.Such post-disturbance changes in abiotic and biotic environments may also promote a naturalized exotic species(or invading species)to become invasive through rapid colonization of the habitat sites by reducing the extent and size of resident plant species.By combining species life history traits with that of the disturbance-induced changes in habitat characteristics,we aimed to determine those interacting factors and associated mechanism allowing an exotic invasion to start off.Methods We used a modified version of the classic competition–colonization(CC)model which was formulated first by Hastings(1980)and studied later by Tilman(1994)to explain spatial coexistence of multiple species.Within this model framework,recruitment-limited spatial competition has explicitly been linked with interspecific resource competition without altering the basic assumptions and structure of the original CC model.Important findings The model results showed that at a constant rate of resource supply,invading species can stably coexist with native species via trade-offs between species competitive ability and colonizing ability.On the other hand,the model predicted that with a fluctuating resource condition,invading species can successfully invade a habitat following continuous reductions in the size and extent of native species.Whether or not invading species holds competitive superiority over the native species for limiting resource,we showed that there exists a range of variation in available resource that allows an exotic invasion to start off in post-disturbance habitat.The associated disturbance-induced mechanism promoting invading species to become invasive has been identified.It states that occurrences of disturbances such as fire or clear-cutting influence variation in resource availability,and in addition open up many vacant microsites;given these disturbance-induced changes,invading species with a higher rate of propagule production and with a higher survival rate of adults particularly in low-resource condition recruits microsites at faster rate relative to native competitor species,and with a given range of variation in resource availabilities,it maintains continued expansions following reductions in size and extent of native species.Moreover,we identified those interacting factors and their specific roles that drive this mechanism.These factors include propagule supply,variable resource level and vacant microsite availability.Increased availability of vacant microsites following disturbances creates an opportunity for rapid colonization.Given this opportunity,higher number of propagules supplied by the invading species enhances the rate of colonization success,whereas the resource variation within a range of given thresholds maintains enhanced colonization rate of the invading species while it depresses native competitor species.Owing to the each factor’s invasion regulatory ability,controlling one or all of them may have strong negative impact on the occurrence of exotic invasion.展开更多
基金This work was supported by the Key Program of Social Science Planning Foundation of Liaoning Province under Grant L21AGL017.
文摘Shared manufacturing is recognized as a new point-to-point manufac-turing mode in the digital era.Shared manufacturing is referred to as a new man-ufacturing mode to realize the dynamic allocation of manufacturing tasks and resources.Compared with the traditional mode,shared manufacturing offers more abundant manufacturing resources and flexible configuration options.This paper proposes a model based on the description of the dynamic allocation of tasks and resources in the shared manufacturing environment,and the characteristics of shared manufacturing resource allocation.The execution of manufacturing tasks,in which candidate manufacturing resources enter or exit at various time nodes,enables the dynamic allocation of manufacturing tasks and resources.Then non-dominated sorting genetic algorithm(NSGA-II)and multi-objective particle swarm optimization(MOPSO)algorithms are designed to solve the model.The optimal parameter settings for the NSGA-II and MOPSO algorithms have been obtained according to the experiments with various population sizes and iteration numbers.In addition,the proposed model’s efficiency,which considers the entries and exits of manufacturing resources in the shared manufacturing environment,is further demonstrated by the overlap between the outputs of the NSGA-II and MOPSO algorithms for optimal resource allocation.
文摘Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitative analysis of the water resources condition in varied environment and prediction of the law of the water resources evolution in the future because year-based time span may best reflect the law of the water resources evolution driven by the nature and human activities in the river basin. This paper advances the theory of annual runoff evolution under natural-artificial dual mode based on the dual mode of the water resources evolution, and the theory is applied for the Wuding River Basin on the middle Yellow River as a case study. A thorough analysis of the precipitation-runoff relationship is made in the case of dynamic variation of ground surface conditions of the Wuding River basin, and the concept of water-soil conservation index area that indicates adoption of various measures for water and soil conservation to reflect ground surface conditions. Furthermore, precipitation-runoff empirical model is developed to reflect dynamic variation of the ground surface conditions of the river basin. The study may lay a solid foundation for the integrated theoretical platform of the law of the water resources evolution in the Yellow River basin and the dual model of the evolution.
基金by the Italian Ministry of Environment(DPN–2008–0008213 and PNM–II–2012–0015691)by the Prefecture of Haute Corse,France(2B–2018–01–92–004).
文摘Ecological networks,usually depicting interactions among species,have been recently down-scaled to the individual level,permitting description of patterns of inter-individual resource variation that are usually hindered at the species level.Optimal diet theory(ODT)models,applied to prey–predator systems,predict different patterns of nestedness and modularity in the network,depending on the available resources and intra-specific competition.The effect of resource availability on the emergence of networks structures,and ODT framework,has not yet fully been clarified.Here,we analyzed the structural patterns of individual-resource networks in 3 species of Mediterranean salamanders,in relation to changes in prey availability.We used weighted individual-resource network metrics to interpret the observed patterns,according to 3 ODT models.We found significant nestedness recurring in our study system,indicating that both selective and opportunistic individuals occur in the same population.Prey diversity,rather than abundance,was apparently related to inter-individual resource variation and promoted the emergence of significant modularity within all networks.The observed patterns of nestedness and modularity,together with the variation in resource diversity and intra-specific competition,are in agreement with the distinct preferences model of ODT.These findings suggest that in the focal prey–predator systems,individuals were able to perceive changes in prey diversity and to exploit in different ways the variations in composition of available resources,shifting their diet assembly rules accordingly.Our findings also confirm that the use of weighted individual-resource networks,in prey–predator systems,allows to disclose dynamics that are masked at the species or population level.
基金US National Science Foundation’s Biocomplexity Program(DEB-0421530)Long Term Ecological Research Program(Sevilleta)(DEB-0620482)and the University of California Agricultural Experiment Station。
文摘Aims Within a habitat of multiple plant species,increased resource availabilities and altered species abundances following disturbances create opportunities for exotic species to successfully establish and subsequently naturalize into its non-native environment.Such post-disturbance changes in abiotic and biotic environments may also promote a naturalized exotic species(or invading species)to become invasive through rapid colonization of the habitat sites by reducing the extent and size of resident plant species.By combining species life history traits with that of the disturbance-induced changes in habitat characteristics,we aimed to determine those interacting factors and associated mechanism allowing an exotic invasion to start off.Methods We used a modified version of the classic competition–colonization(CC)model which was formulated first by Hastings(1980)and studied later by Tilman(1994)to explain spatial coexistence of multiple species.Within this model framework,recruitment-limited spatial competition has explicitly been linked with interspecific resource competition without altering the basic assumptions and structure of the original CC model.Important findings The model results showed that at a constant rate of resource supply,invading species can stably coexist with native species via trade-offs between species competitive ability and colonizing ability.On the other hand,the model predicted that with a fluctuating resource condition,invading species can successfully invade a habitat following continuous reductions in the size and extent of native species.Whether or not invading species holds competitive superiority over the native species for limiting resource,we showed that there exists a range of variation in available resource that allows an exotic invasion to start off in post-disturbance habitat.The associated disturbance-induced mechanism promoting invading species to become invasive has been identified.It states that occurrences of disturbances such as fire or clear-cutting influence variation in resource availability,and in addition open up many vacant microsites;given these disturbance-induced changes,invading species with a higher rate of propagule production and with a higher survival rate of adults particularly in low-resource condition recruits microsites at faster rate relative to native competitor species,and with a given range of variation in resource availabilities,it maintains continued expansions following reductions in size and extent of native species.Moreover,we identified those interacting factors and their specific roles that drive this mechanism.These factors include propagule supply,variable resource level and vacant microsite availability.Increased availability of vacant microsites following disturbances creates an opportunity for rapid colonization.Given this opportunity,higher number of propagules supplied by the invading species enhances the rate of colonization success,whereas the resource variation within a range of given thresholds maintains enhanced colonization rate of the invading species while it depresses native competitor species.Owing to the each factor’s invasion regulatory ability,controlling one or all of them may have strong negative impact on the occurrence of exotic invasion.
