Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion ...Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality(MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.展开更多
Wireless sensor networks （WSNs） can be used to collect surrounding data by multi-hop. As sensor networks have the constrained and not rechargeable energy resource, energy efficiency is an important design issue for ...Wireless sensor networks （WSNs） can be used to collect surrounding data by multi-hop. As sensor networks have the constrained and not rechargeable energy resource, energy efficiency is an important design issue for its topology. In this paper, the energy consumption issue under the different topology is studied. We derive the exact mathematical expression of energy consumption for the fiat and clustering scheme, respectively. Then the energy consumptions of different schemes are compared. By the comparison, multi-level clustering scheme is more energy efficient in large scale networks. Simulation results demonstrate that our analysis is correct from the view of prolonging the large-scale network lifetime and achieving more power reductions.展开更多
According to Michael Porter＇s Diamond Model, a business cluster is defined as geographic concentration of inter-connected companies and institutions working in a common industry. In addition, clusters encompass an ar...According to Michael Porter＇s Diamond Model, a business cluster is defined as geographic concentration of inter-connected companies and institutions working in a common industry. In addition, clusters encompass an array of collaborating and competing services and providers that create a specialized infrastructure, which supports the cluster＇s industry. The economic cluster model, represents a synergy, a dynamic relationship and a network between not only the companies that comprise a cluster but also the successful partnering of the stakeholders. Today in all over the world, successful clusters have established a greater competitive advantage and wealth creation for their regions when compared to companies not in a cluster. Given this success more policy makers and regions are considering fostering cluster development as building blocks of regional economies. Research is planned and performed for understanding the clustering in SMEs （small and medium enterprises） industrial estate in Istanbul if it gives a competitive advantage to the cluster members or not. It is performed to determine and satisfy the lack of knowledge about the small and medium enterprises＇ issues, technologic systems, production quality standards, capacity usage ratios, interactions with other firms, habits of following the technologic improvements and clustering effects on the members.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41571112)Natural Science Foundation of Zhejiang Province of China(No.LY16D010002)
文摘Local governments have long been ardently pursuing the industrial specialization effect(MAR externalities) and industrial diversification effect(Jacobs externalities). Such a pursuit has resulted in severe distortion of resource allocation and negative effect on sustainability of local economic development. Regarding the effect from both MAR and Jacobs externalities on local economic development existing literature records notable disputes. Therefore, for local economic development, one important issue is which externality(MAR or Jacobs) can better bring the effect into play. By studying a panel data of 283 Chinese cities from 2003 to 2012 and applying dynamic plane data GMM method, this paper conducted a regression analysis of the relationship among industrial agglomeration externalities, city size, and regional economic development. The result indicates that with regard to the whole nation, MAR externalities are conducive to regional economy development whereas Jacobs externalities will, to an extent, restrain regional economic development. As regards eastern, middle, and western regions, MAR externalities are conducive only to the economic development of the eastern region; their effects on middle and western regions are insignificant. Moreover, the interaction item between MAR externalities and city size has a significant negative synergistic effect on national economic development and a certain acceleration effect on eastern region as well as a strong negative synergistic effect on the middle region and an insignificant effect on the western region. The interaction item between Jacobs externalities and city size has a positive synergistic effect on only the middle region and has an insignificant synergistic effect on both eastern and western regions. Capital stock and labor input have significant accelerating effects on GDP growth per capita of Chinese cities, whereas material capital and labor input remain primary driving forces for Chinese local economic development. Furthermore, human capital contributes to accelerating urban economic development, whereas government intervention restrains urban economic development.
文摘Wireless sensor networks （WSNs） can be used to collect surrounding data by multi-hop. As sensor networks have the constrained and not rechargeable energy resource, energy efficiency is an important design issue for its topology. In this paper, the energy consumption issue under the different topology is studied. We derive the exact mathematical expression of energy consumption for the fiat and clustering scheme, respectively. Then the energy consumptions of different schemes are compared. By the comparison, multi-level clustering scheme is more energy efficient in large scale networks. Simulation results demonstrate that our analysis is correct from the view of prolonging the large-scale network lifetime and achieving more power reductions.
文摘According to Michael Porter＇s Diamond Model, a business cluster is defined as geographic concentration of inter-connected companies and institutions working in a common industry. In addition, clusters encompass an array of collaborating and competing services and providers that create a specialized infrastructure, which supports the cluster＇s industry. The economic cluster model, represents a synergy, a dynamic relationship and a network between not only the companies that comprise a cluster but also the successful partnering of the stakeholders. Today in all over the world, successful clusters have established a greater competitive advantage and wealth creation for their regions when compared to companies not in a cluster. Given this success more policy makers and regions are considering fostering cluster development as building blocks of regional economies. Research is planned and performed for understanding the clustering in SMEs （small and medium enterprises） industrial estate in Istanbul if it gives a competitive advantage to the cluster members or not. It is performed to determine and satisfy the lack of knowledge about the small and medium enterprises＇ issues, technologic systems, production quality standards, capacity usage ratios, interactions with other firms, habits of following the technologic improvements and clustering effects on the members.
