Existing research on data collection using wireless mobile vehicle network emphasizes the reliable delivery of information.However,other performance requirements such as life cycle of nodes,stability and security are ...Existing research on data collection using wireless mobile vehicle network emphasizes the reliable delivery of information.However,other performance requirements such as life cycle of nodes,stability and security are not set as primary design objectives.This makes data collection ability of vehicular nodes in real application environment inferior.By considering the features of nodes in wireless IoV,such as large scales of deployment,volatility and low time delay,an efficient data collection algorithm is proposed for mobile vehicle network environment.An adaptive sensing model is designed to establish vehicular data collection protocol.The protocol adopts group management in model communication.The vehicular sensing node in group can adjust network sensing chain according to sensing distance threshold with surrounding nodes.It will dynamically choose a combination of network sensing chains on basis of remaining energy and location characteristics of surrounding nodes.In addition,secure data collection between sensing nodes is undertaken as well.The simulation and experiments show that the vehicular node can realize secure and real-time data collection.Moreover,the proposed algorithm is superior in vehicular network life cycle,power consumption and reliability of data collection by comparing to other algorithms.展开更多
In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of cli...In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of climate change are likely to trigger adaptive responses that influence environmental and socio-economic drivers of food system performance in positive as well as negative ways. This paper was conducted through the collection of some research materials with the projected balance of these various climate impacts on food system performance and food security outcomes at the local and global levels. More so that, food security is likely to be affected by climate change in several ways： food security depends not only on the direct impact of climate change on food production but also on its indirect impact on human nutrition and health, economic growth, trade flows and food aid policy. The paper further examined the effectiveness of managing new risks and uncertainty, improving the quality of information and its use, monitoring weather and improving scientific understanding of climate change, promoting insurance schemes, maintaining biodiversity and access to fund as some of the crucial measures for adaptation. The large amount of resources that would be necessary to avoid the worst case scenario suggests the necessity of continued support from the international community to improve food security at the local and global levels as a whole.展开更多
To describe the design approaches of IND-CCA2 （adaptive chosen ciphertext attack） secure public key encryption schemes systematically, the gaps between different kinds of intractable problems and IND-CCA2 security a...To describe the design approaches of IND-CCA2 （adaptive chosen ciphertext attack） secure public key encryption schemes systematically, the gaps between different kinds of intractable problems and IND-CCA2 security are studied. This paper points out that the construction of IND-CCA2 secure schemes is essentially to bridge these gaps. These gaps are categorized, analyzed and measured. Finally the methods to bridge these gaps are described. This explains the existing design approaches and gives an intuition about the difficulty of designing IND-CCA2 secure public key encryption schemes based on different types of assumptions.展开更多
基金supported by the National Nature Science Foundation of China(Grant61572188)A Project Supported by Scientif ic Research Fund of Hunan Provincial Education Department(14A047)+4 种基金the Natural Science Foundation of Fujian Province(Grant no.2014J05079)the Young and Middle-Aged Teachers Education Scientific Research Project of Fujian province(Grant nos.JA13248JA14254 and JA15368)the special scientific research funding for colleges and universities from Fujian Provincial Education Department(Grant no.JK2013043)the Research Project supported by Xiamen University of Technology(YKJ15019R)
文摘Existing research on data collection using wireless mobile vehicle network emphasizes the reliable delivery of information.However,other performance requirements such as life cycle of nodes,stability and security are not set as primary design objectives.This makes data collection ability of vehicular nodes in real application environment inferior.By considering the features of nodes in wireless IoV,such as large scales of deployment,volatility and low time delay,an efficient data collection algorithm is proposed for mobile vehicle network environment.An adaptive sensing model is designed to establish vehicular data collection protocol.The protocol adopts group management in model communication.The vehicular sensing node in group can adjust network sensing chain according to sensing distance threshold with surrounding nodes.It will dynamically choose a combination of network sensing chains on basis of remaining energy and location characteristics of surrounding nodes.In addition,secure data collection between sensing nodes is undertaken as well.The simulation and experiments show that the vehicular node can realize secure and real-time data collection.Moreover,the proposed algorithm is superior in vehicular network life cycle,power consumption and reliability of data collection by comparing to other algorithms.
文摘In view of the fact that climate-related disasters are already taking a heavy toll, causing massive damage to crops and infrastructure and forcing some people to flee their homes, however, the potential impacts of climate change are likely to trigger adaptive responses that influence environmental and socio-economic drivers of food system performance in positive as well as negative ways. This paper was conducted through the collection of some research materials with the projected balance of these various climate impacts on food system performance and food security outcomes at the local and global levels. More so that, food security is likely to be affected by climate change in several ways： food security depends not only on the direct impact of climate change on food production but also on its indirect impact on human nutrition and health, economic growth, trade flows and food aid policy. The paper further examined the effectiveness of managing new risks and uncertainty, improving the quality of information and its use, monitoring weather and improving scientific understanding of climate change, promoting insurance schemes, maintaining biodiversity and access to fund as some of the crucial measures for adaptation. The large amount of resources that would be necessary to avoid the worst case scenario suggests the necessity of continued support from the international community to improve food security at the local and global levels as a whole.
基金the National Natural Science Foundation of China(Nos.60573032,60773092,90604036)
文摘To describe the design approaches of IND-CCA2 （adaptive chosen ciphertext attack） secure public key encryption schemes systematically, the gaps between different kinds of intractable problems and IND-CCA2 security are studied. This paper points out that the construction of IND-CCA2 secure schemes is essentially to bridge these gaps. These gaps are categorized, analyzed and measured. Finally the methods to bridge these gaps are described. This explains the existing design approaches and gives an intuition about the difficulty of designing IND-CCA2 secure public key encryption schemes based on different types of assumptions.
