The connection between production scheduling and transportation scheduling is getting closer in smart manufacturing system, and both of those problems are summarized as NP-hard problems. However, only a few studies ha...The connection between production scheduling and transportation scheduling is getting closer in smart manufacturing system, and both of those problems are summarized as NP-hard problems. However, only a few studies have considered them simultaneously. This paper solves the integrated production and transportation scheduling problem(IPTSP) in hybrid flow shops, which is an extension of the hybrid flow shop scheduling problem(HFSP). In addition to the production scheduling on machines, the transportation scheduling process on automated guided vehicles(AGVs)is considered as another optimization process. In this problem, the transfer tasks of jobs are performed by a certain number of AGVs. To solve it, we make some preparation(including the establishment of task pool, the new solution representation and the new solution evaluation), which can ensure that satisfactory solutions can be found efficiently while appropriately reducing the scale of search space. Then, an effective genetic tabu search algorithm is used to minimize the makespan. Finally, two groups of instances are designed and three types of experiments are conducted to evaluate the performance of the proposed method. The results show that the proposed method is effective to solve the integrated production and transportation scheduling problem.展开更多
Urbanization effects on living organisms are spatially heterogeneous.Here we quantified the abundance of birds per tree in forested urban and rural habitats for 85,829 trees mainly in China and Europe.A population mod...Urbanization effects on living organisms are spatially heterogeneous.Here we quantified the abundance of birds per tree in forested urban and rural habitats for 85,829 trees mainly in China and Europe.A population model was based on the assumption that:1)birds have a normally distributed habitat preference;2)an increase in population size linked to the habitat preference;3)a population size dependent on the habitat preference;and 4)the removal of a certain fraction of individuals giving rise to extinction.We tested for large-scale differences in the impact of urbanization on the frequency distribution of the difference in abundance between urban and rural habitats in China and parts of Europe.The difference in the frequency distribution of urban population density of birds in trees minus rural population density of birds in trees in China and Europe was statistically significant suggesting that the abundance of birds differed between trees in urban and rural habitats,but more so in China than in Europe.We hypothesize that more pronounced differences in China than in Europe may have arisen due to the Four Pests Campaign in 1958-1962 that resulted in death of hundreds of millions of birds(mainly tree sparrows Passer monfanus,but also numerous other less common species that were starting to become urbanized around 1960).Species that were less common in 1960 could not sustain reductions in population size in urban areas and hence these species are still rare or absent in urban areas today 60 years later.展开更多
In Zhejiang Province, in a context of villages undergoing rapid structural change in terms of population, employment, and residents' demands, the village planning is featured by being based on more detailed regula...In Zhejiang Province, in a context of villages undergoing rapid structural change in terms of population, employment, and residents' demands, the village planning is featured by being based on more detailed regulations and presented through more diversified planning schemes. It aims at optimizing the urban-rural spatial structure by reshaping the layout of rural settlements, improving the rural industries by enhancing the studies on industrial development, catering to the villagers' needs by exploring effective approaches to the equalization of public services, and promoting the eff iciency of village planning implementation by developing effective measures. Taking the practice of Zhejiang Province as an example, this paper tries to summarize the features of the village planning scheme compilation in the context of rapid structural change and to explore the possible approaches to a coordinated urban and rural development.展开更多
基金Supported by National Key R&D Program of China (Grant No. 2019YFB1704603)National Natural Science Foundation of China (Grant Nos. U21B2029 and 51825502)。
文摘The connection between production scheduling and transportation scheduling is getting closer in smart manufacturing system, and both of those problems are summarized as NP-hard problems. However, only a few studies have considered them simultaneously. This paper solves the integrated production and transportation scheduling problem(IPTSP) in hybrid flow shops, which is an extension of the hybrid flow shop scheduling problem(HFSP). In addition to the production scheduling on machines, the transportation scheduling process on automated guided vehicles(AGVs)is considered as another optimization process. In this problem, the transfer tasks of jobs are performed by a certain number of AGVs. To solve it, we make some preparation(including the establishment of task pool, the new solution representation and the new solution evaluation), which can ensure that satisfactory solutions can be found efficiently while appropriately reducing the scale of search space. Then, an effective genetic tabu search algorithm is used to minimize the makespan. Finally, two groups of instances are designed and three types of experiments are conducted to evaluate the performance of the proposed method. The results show that the proposed method is effective to solve the integrated production and transportation scheduling problem.
基金This study was supported by the National Natural Science Foundation of China(Nos 31472013 and 31772453 to W.L.)GDAS Special Project of Science and Technology Development(Nos 2017 GDASCX-0107,2018 GDASCX-0107)to F.S.Z.
文摘Urbanization effects on living organisms are spatially heterogeneous.Here we quantified the abundance of birds per tree in forested urban and rural habitats for 85,829 trees mainly in China and Europe.A population model was based on the assumption that:1)birds have a normally distributed habitat preference;2)an increase in population size linked to the habitat preference;3)a population size dependent on the habitat preference;and 4)the removal of a certain fraction of individuals giving rise to extinction.We tested for large-scale differences in the impact of urbanization on the frequency distribution of the difference in abundance between urban and rural habitats in China and parts of Europe.The difference in the frequency distribution of urban population density of birds in trees minus rural population density of birds in trees in China and Europe was statistically significant suggesting that the abundance of birds differed between trees in urban and rural habitats,but more so in China than in Europe.We hypothesize that more pronounced differences in China than in Europe may have arisen due to the Four Pests Campaign in 1958-1962 that resulted in death of hundreds of millions of birds(mainly tree sparrows Passer monfanus,but also numerous other less common species that were starting to become urbanized around 1960).Species that were less common in 1960 could not sustain reductions in population size in urban areas and hence these species are still rare or absent in urban areas today 60 years later.
基金Jointly funded by the research project of A Study on the Compilation of County(County-Level City)Master Plan:Methods and Implementation Mechanismsponsored by the Ministry of Housing and Urban-Rural Development and the research project of A Study on Planning Standards of Key Towns and Villages in Zhejiang Provincesponsored by the Department of Housing and Urban-Rural Development of Zhejiang Province
文摘In Zhejiang Province, in a context of villages undergoing rapid structural change in terms of population, employment, and residents' demands, the village planning is featured by being based on more detailed regulations and presented through more diversified planning schemes. It aims at optimizing the urban-rural spatial structure by reshaping the layout of rural settlements, improving the rural industries by enhancing the studies on industrial development, catering to the villagers' needs by exploring effective approaches to the equalization of public services, and promoting the eff iciency of village planning implementation by developing effective measures. Taking the practice of Zhejiang Province as an example, this paper tries to summarize the features of the village planning scheme compilation in the context of rapid structural change and to explore the possible approaches to a coordinated urban and rural development.
