This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G)....This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.展开更多
The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.
Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific...Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling.展开更多
The software industry has evolved to a multiple-product development created on a platform and based on a common architecture integrated to other systems. This integration happens through components and third-party dev...The software industry has evolved to a multiple-product development created on a platform and based on a common architecture integrated to other systems. This integration happens through components and third-party developers networks in Software Ecosystems (SECOs). Since systems and software development processes present challenges beyond the technical side, SECOs have emerged as an approach to improve the Software Engineering (SE) mindset in the industry. This fact changes the software industry as it requires the management of an integrated social-based environment to support a transition from an intra-organizational to an open business model approach towards a SECO approach. In this context, social networks can be important to coordinate a collaborative and distributed environment to develop SECOs platforms. This paper analyses the impact of social networks in SECOs through an integrated framework of the SECO and social network challenges. So, a proposal for a sociotechnical-based architecture to support the SECOs lifecycle is discussed.展开更多
<span style="font-family:Verdana;">The eddy covariance technique is an accurate and direct tool to measure the Net Ecosystem Exchange (NEE) of carbon dioxide. However, sometimes conditions are not amen...<span style="font-family:Verdana;">The eddy covariance technique is an accurate and direct tool to measure the Net Ecosystem Exchange (NEE) of carbon dioxide. However, sometimes conditions are not amenable to measurements using this technique. Thus, different methods have been developed to allow gap-filling and quality assessment of eddy covariance data sets. In this study first, two different Artificial Neural Networks (ANNs) approaches, the Multi-layer Perceptron (MLP) trained by the Back-Propagation (BP) algorithm, and the Radial Basis Function (RBF), were used to fill missing NEE data measured above rain-fed maize at the University of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebraska. The gap-filled data were then compared by different statistical indices to gap-filled data obtained with the technique suggested by Suyker and Verma in 2005 [S&V method], and the ANN approach presented by Papale in 2003. The results showed that the RBF network was able to find better fits for missing values compared to the MLP (BP) network and S&V method. In addition, unlike the S&V method, which depends on different gap-filling procedures over the year;the structure of RBF and MLP (BP) networks was constant. However, data analysis indicated Papale’s approach gave better fits than the RBF and MLP (BP) methods. Thus, based on this work, Papale’s approach is the best method to estimate the missing data;though the applied statistical indices, which were used for model evaluation, show little difference between Papale’s approach and the RBF and MLP (BP).</span>展开更多
A mass-balanced model was constructed to determine the flow-energy in a community of fishes and invertebrates in the Beibu Gulf, northern South China Sea using Ecopath and Ecosim software. Input parameters were taken ...A mass-balanced model was constructed to determine the flow-energy in a community of fishes and invertebrates in the Beibu Gulf, northern South China Sea using Ecopath and Ecosim software. Input parameters were taken from the literature, except for the biomass of fish groups which was obtained from trawl surveys during October 1997 to May 1999 in the study area. The model consisted of 16 functional groups （boxes）, including one marine mammal and seabirds, each representing organisms with a similar role in the food web, and only covered the main trophic flow in the Beibu Gulf ecosystem. The results showed that the food web of Beibu Gulf was dominated by the detrital path and benthic invertebrates played a significant role in transferring energy from the detritus to higher trophic levels; phytoplankton was a primary producer and most utilized as a food source. Fractional trophic levels ranged from 1.0 to 4.08 with marine mammals occupying the highest trophic level. Using network analysis, the system network was mapped into a linear food chain and six discrete trophic levels were found with a mean transfer efficiency of 16.7% from the detritus, 16.2% from the primary producer within the ecosystem. The biomass density of the commercially utilized species estimated by the model is 8.46 t/km^2, only O. 48% of the net primary production.展开更多
植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生...植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)中位于中国干旱半干旱区的2个草地生态系统观测研究站(海北站、内蒙古站)和5个荒漠生态系统类型观测研究站(鄂尔多斯站、阜康站、临泽站、奈曼站、沙坡头站)的典型生态系统,对其按照CERN生态系统长期观测规范开展长期观测获取的植被地上生物量的2005–2020年间生长季的月动态实测数据进行了收集整理与质量控制,并开展了样方原始调查数据到样地尺度观测数据的统计计算,生成了植被地上生物量数据集,可为中国干旱半干旱区草地和荒漠生态系统对全球气候变化响应及植被保育与可持续发展等研究提供地面观测数据支撑。展开更多
文摘This paper applies the perspective of business ecosystem to mobile communications industry,trying to help mobile network operators improve their strategies in the era of the third generation mobile communications(3G).According to the definition of the business ecosystem,the ecosystem structure of mobile network operators is analyzed.As an important hub in the ecosystem,mobile network operators are advised to take a keystone strategy.The key points of the strategy are summarized.Finally,suggestions for Chinese mobile network operators are given based on the analysis.
文摘The article analyzes the development of the Chinese Ecosystem Research Network, and its mission, mandate, and management mechanisms, with examples of research, demonstration and consultation for policy-setting.
文摘Objective To recognize and assess the impact of the South-to-north Water Transfer Project (SNWTP) on the ecological environment of Xiangfan, Hubei Province, situated in the water-out area, and develop sound scientific countermeasures. Methods A three-layer BP network was built to simulate topology and process of the eco-economy system of Xiangfan. Historical data of ecological environmental factors and socio-economic factors as inputs, and corresponding historical data of ecosystem service value (ESV) and GDP as target outputs, were presented to train and test the network. When predicted input data after 2001 were presented to trained network as generalization sets, ESVs and GDPs of 2002, 2003, 2004... till 2050 were simulated as output in succession. Results Up to 2050, the area would have suffered an accumulative total ESV loss of RMB 104.9 billion, which accounted for 37.36% of the present ESV. The coinstantaneous GDP would change asynchronously with ESV, it would go through an up-to-down process and finally lose RMB89.3 billion, which accounted for 18.71% of 2001. Conclusions The simulation indicates that ESV loss means damage to the capability of socio-economic sustainable development, and suggests that artificial neural networks (ANNs) provide a feasible and effective method and have an important potential in ESV modeling.
文摘The software industry has evolved to a multiple-product development created on a platform and based on a common architecture integrated to other systems. This integration happens through components and third-party developers networks in Software Ecosystems (SECOs). Since systems and software development processes present challenges beyond the technical side, SECOs have emerged as an approach to improve the Software Engineering (SE) mindset in the industry. This fact changes the software industry as it requires the management of an integrated social-based environment to support a transition from an intra-organizational to an open business model approach towards a SECO approach. In this context, social networks can be important to coordinate a collaborative and distributed environment to develop SECOs platforms. This paper analyses the impact of social networks in SECOs through an integrated framework of the SECO and social network challenges. So, a proposal for a sociotechnical-based architecture to support the SECOs lifecycle is discussed.
文摘<span style="font-family:Verdana;">The eddy covariance technique is an accurate and direct tool to measure the Net Ecosystem Exchange (NEE) of carbon dioxide. However, sometimes conditions are not amenable to measurements using this technique. Thus, different methods have been developed to allow gap-filling and quality assessment of eddy covariance data sets. In this study first, two different Artificial Neural Networks (ANNs) approaches, the Multi-layer Perceptron (MLP) trained by the Back-Propagation (BP) algorithm, and the Radial Basis Function (RBF), were used to fill missing NEE data measured above rain-fed maize at the University of Nebraska-Lincoln Agricultural Research and Development Center near Mead, Nebraska. The gap-filled data were then compared by different statistical indices to gap-filled data obtained with the technique suggested by Suyker and Verma in 2005 [S&V method], and the ANN approach presented by Papale in 2003. The results showed that the RBF network was able to find better fits for missing values compared to the MLP (BP) network and S&V method. In addition, unlike the S&V method, which depends on different gap-filling procedures over the year;the structure of RBF and MLP (BP) networks was constant. However, data analysis indicated Papale’s approach gave better fits than the RBF and MLP (BP) methods. Thus, based on this work, Papale’s approach is the best method to estimate the missing data;though the applied statistical indices, which were used for model evaluation, show little difference between Papale’s approach and the RBF and MLP (BP).</span>
文摘A mass-balanced model was constructed to determine the flow-energy in a community of fishes and invertebrates in the Beibu Gulf, northern South China Sea using Ecopath and Ecosim software. Input parameters were taken from the literature, except for the biomass of fish groups which was obtained from trawl surveys during October 1997 to May 1999 in the study area. The model consisted of 16 functional groups （boxes）, including one marine mammal and seabirds, each representing organisms with a similar role in the food web, and only covered the main trophic flow in the Beibu Gulf ecosystem. The results showed that the food web of Beibu Gulf was dominated by the detrital path and benthic invertebrates played a significant role in transferring energy from the detritus to higher trophic levels; phytoplankton was a primary producer and most utilized as a food source. Fractional trophic levels ranged from 1.0 to 4.08 with marine mammals occupying the highest trophic level. Using network analysis, the system network was mapped into a linear food chain and six discrete trophic levels were found with a mean transfer efficiency of 16.7% from the detritus, 16.2% from the primary producer within the ecosystem. The biomass density of the commercially utilized species estimated by the model is 8.46 t/km^2, only O. 48% of the net primary production.
文摘植被生物量是全球碳循环的重要组成部分,是陆地生态系统与大气之间碳交换的重要环节,是定量研究全球气候变化与草地、荒漠生态系统之间的反馈调节作用等的基础。中国干旱半干旱区的草地、荒漠生态系统是重要的碳库类型,本文选取中国生态系统研究网络(Chinese Ecosystem Research Network,CERN)中位于中国干旱半干旱区的2个草地生态系统观测研究站(海北站、内蒙古站)和5个荒漠生态系统类型观测研究站(鄂尔多斯站、阜康站、临泽站、奈曼站、沙坡头站)的典型生态系统,对其按照CERN生态系统长期观测规范开展长期观测获取的植被地上生物量的2005–2020年间生长季的月动态实测数据进行了收集整理与质量控制,并开展了样方原始调查数据到样地尺度观测数据的统计计算,生成了植被地上生物量数据集,可为中国干旱半干旱区草地和荒漠生态系统对全球气候变化响应及植被保育与可持续发展等研究提供地面观测数据支撑。
