This paper focuses on optimally determining the existence of connected paths between some given nodes in random ring-based graphs.Serving as a fundamental underlying structure in network modeling,ring topology appears...This paper focuses on optimally determining the existence of connected paths between some given nodes in random ring-based graphs.Serving as a fundamental underlying structure in network modeling,ring topology appears as commonplace in many realistic scenarios.Regarding this,we consider graphs composed of rings,with some possible connected paths between them.Without prior knowledge of the exact node permutations on rings,the existence of each edge can be unraveled through edge testing at a unit cost in one step.The problem examined is that of determining whether the given nodes are connected by a path or separated by a cut,with the minimum expected costs involved.Dividing the problem into different cases based on different topologies of the ring-based networks,we propose the corresponding policies that aim to quickly seek the paths between nodes.A common feature shared by all those policies is that we stick to going in the same direction during edge searching,with edge testing in each step only involving the test between the source and the node that has been tested most.The simple searching rule,interestingly,can be interpreted as a delightful property stemming from the neat structure of ring-based networks,which makes the searching process not rely on any sophisticated behaviors.We prove the optimality of the proposed policies by calculating the expected cost incurred and making a comparison with the other class of strategies.The effectiveness of the proposed policies is also verified through extensive simulations,from which we even disclose three extra intriguing findings:i)in a onering network,the cost will grow drastically with the number of designated nodes when the number is small and will grow slightly when that number is large;ii)in ring-based network,Depth First is optimal in detecting the connectivity between designated nodes;iii)the problem of multi-ring networks shares large similarity with that of two-ring networks,and a larger number of ties between rings will not influence the expected cost.展开更多
The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support I...The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support IP packet marking or detected agents. So far, this requirement is not satisfied. On the basis of traditional traceroute,this paper investigates the efficiency of discovering path methods from aspects of the size and order of detecting packets, and the length of paths.It points out that the size of padding in probed packets has a slight effect on discovering latency, and the latency with the method of bulk sending receiving is much smaller than one with the traditional traceroute. Moreover, the loss rate of packets with the technique of TTL (Time To Live) which increases monotonously is less than that with the technique of TTL which decreases monotonously. Lastly,OS (Operating System) passive fingerprint is used as heuristic to predict the length of the discovered path so as to reduce disturbance in network traffic.展开更多
Securities fraud is a common worldwide problem, resulting in serious negative consequences to securities market each year. Securities Regulatory Commission from various countries has also attached great importance to ...Securities fraud is a common worldwide problem, resulting in serious negative consequences to securities market each year. Securities Regulatory Commission from various countries has also attached great importance to the detection and prevention of securities fraud activities. Securities fraud is also increasing due to the rapid expansion of securities market in China. In accomplishing the task of securities fraud detection, China Securities Regulatory Commission (CSRC) could be facilitated in their work by using a number of data mining techniques. In this paper, we investigate the usefulness of Logistic regression model, Neural Networks (NNs), Sequential minimal optimization (SMO), Radial Basis Function (RBF) networks, Bayesian networks and Grammar Based Genet- ic Programming (GBGP) in the classification of the real, large and latest China Corporate Securities Fraud (CCSF) database. The six data mining techniques are compared in terms of their performances. As a result, we found GBGP outperforms others. This paper describes the GBGP in detail in solving the CCSF problem. In addition, the Synthetic Minority Over-sampling Technique (SMOTE) is applied to generate synthetic minority class examples for the imbalanced CCSF dataset.展开更多
Li Xinfeng, a research fellow at the Chinese Academy of Social Scienc- es, served as the chief correspond- ent with the People＇s Daily in South Africa from 1998 to 2005. Li was in charge of the news coverage in the s...Li Xinfeng, a research fellow at the Chinese Academy of Social Scienc- es, served as the chief correspond- ent with the People＇s Daily in South Africa from 1998 to 2005. Li was in charge of the news coverage in the southern, eastern and central African regions and traveled across the continent, visiting over 20 AfrF can countries. His bookA Reporter＇s Exploration： Following Zheng He＇s Footsteps in Africa, marks China＇s first book on Zheng He＇s voyage to Africa, which filled the gap in the research on the history of Sino-African relations. Back in the 15th century, Zheng He, a famous Chinese admiral, sailed with his fleet as far as East Africa. Recently, Li spoke to ChinAfrica about his ex- periences in Africa as a journalist.展开更多
Writers Wang Yan and Wu Fugui’s book guides Chinese readers through Sudan’s 25 states and districts as they witnessed them before the country’s split last year HOW much is actually known about arab states-particula...Writers Wang Yan and Wu Fugui’s book guides Chinese readers through Sudan’s 25 states and districts as they witnessed them before the country’s split last year HOW much is actually known about arab states-particularly that of Sudan in North africa？ Looking closely at this question, it becomes clear that there is much still un展开更多
1 Dinosaur Eggs in Yiwu City, Zhejiang Province In February 2017, dinosaur egg fossils were discovered in China Town part of Yiwu City, Zhejiang Province. They were confirmed by dinosaur experts from the Zhejiang Muse...1 Dinosaur Eggs in Yiwu City, Zhejiang Province In February 2017, dinosaur egg fossils were discovered in China Town part of Yiwu City, Zhejiang Province. They were confirmed by dinosaur experts from the Zhejiang Museum of Natural History to be those of Mesozoic herbivorous dinosaurs （Fig. 1）. Not long before, Yiwu Museum staff had discovered dinosaur eggs close by this place.展开更多
Objective The Yanshan Fold Belt is located within the northern margin of the North China platform and contains welldeveloped and widespread Neoproterozoic and Mesoproterozoic sedimentary units with a total thickness o...Objective The Yanshan Fold Belt is located within the northern margin of the North China platform and contains welldeveloped and widespread Neoproterozoic and Mesoproterozoic sedimentary units with a total thickness of up to 9000 m.Previous studies identified many oil seedlings as well as asphalt and ancient hydrocarbon reservoirs in Northern Hebei depression and western Liaoning depression.This research indicates that the Mesoproterozoic and Neoproterozoic sedimentary units are ideally suited for the formation of significant oil and gas resources.The Niu D1 well was drilled by the China Geological Survey(CGS)in the Niuyingzi area and intercepted oil immersions and oil-and gas-bearing units within a limestone reservoir in the middle Proterozoic Gaoyuzhuang Formation(Fig.1).This study presents new biomarker compound and carbon isotope data that indicate that the oil within this formation was derived from hydrocarbon source rocks of the Hongshuizhuang Formation,part of the Mesoproterozoic Jixian Series,and the reservoir type is overthrust fault fractured anticline hydrocarbon reservoir.The oil reservoir within the Gaoyuzhuang Formation limestone might represent the oldest oil reservoir discovered to date within the Yanliao faulted depression zone.展开更多
The 2019 Annual Symposium on Yunyang Dinosaur Fossil Protection and Research was held in Chongqing on December 16,2019.It was proposed in the symposium that the dinosaurs discovered from the early Middle Jurassic Xint...The 2019 Annual Symposium on Yunyang Dinosaur Fossil Protection and Research was held in Chongqing on December 16,2019.It was proposed in the symposium that the dinosaurs discovered from the early Middle Jurassic Xintiangou Formation in Yunyang,Chongqing could represent a new dinosaur fauna.Previously,only a few dinosaurs have been reported from the Xintiangou Formation.Moreover,the Xintiangou dinosaurs are playing an important role in studying the evolutionary sequence of dinosaurs,and have the potential to fill the gaps during the Early-Middle dinosaur turnover.展开更多
Hot Dry Rock （HDR） refers to those generally deeply buried impermeable metamorphic or crystallized biotite gneiss, granite and granodiorite rock bodies, with a burial depth greater than 2000 m, containing no water o...Hot Dry Rock （HDR） refers to those generally deeply buried impermeable metamorphic or crystallized biotite gneiss, granite and granodiorite rock bodies, with a burial depth greater than 2000 m, containing no water or vapor. HDR is as implied, hot and dry, with temperatures ranging from 150 to 650℃, and it can be utilized as a heat resource. Because this type of heat system does not require porosity, permeability and fluids and is widespread at the drillable depth range of 10 kin, it is thereby an infinite resource type. By contrast, thermal power generation results in copious pollution; wind power is irregular and unstable; solar energy occupies large areas.展开更多
基金supported by NSF China(No.61960206002,62020106005,42050105,62061146002)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University。
文摘This paper focuses on optimally determining the existence of connected paths between some given nodes in random ring-based graphs.Serving as a fundamental underlying structure in network modeling,ring topology appears as commonplace in many realistic scenarios.Regarding this,we consider graphs composed of rings,with some possible connected paths between them.Without prior knowledge of the exact node permutations on rings,the existence of each edge can be unraveled through edge testing at a unit cost in one step.The problem examined is that of determining whether the given nodes are connected by a path or separated by a cut,with the minimum expected costs involved.Dividing the problem into different cases based on different topologies of the ring-based networks,we propose the corresponding policies that aim to quickly seek the paths between nodes.A common feature shared by all those policies is that we stick to going in the same direction during edge searching,with edge testing in each step only involving the test between the source and the node that has been tested most.The simple searching rule,interestingly,can be interpreted as a delightful property stemming from the neat structure of ring-based networks,which makes the searching process not rely on any sophisticated behaviors.We prove the optimality of the proposed policies by calculating the expected cost incurred and making a comparison with the other class of strategies.The effectiveness of the proposed policies is also verified through extensive simulations,from which we even disclose three extra intriguing findings:i)in a onering network,the cost will grow drastically with the number of designated nodes when the number is small and will grow slightly when that number is large;ii)in ring-based network,Depth First is optimal in detecting the connectivity between designated nodes;iii)the problem of multi-ring networks shares large similarity with that of two-ring networks,and a larger number of ties between rings will not influence the expected cost.
文摘The technique of IP traceback may effectively block DOS (Denial Of Service) and meet the requirement of the computer forensic, but its accuracy depends upon that condition that each node in the Internet must support IP packet marking or detected agents. So far, this requirement is not satisfied. On the basis of traditional traceroute,this paper investigates the efficiency of discovering path methods from aspects of the size and order of detecting packets, and the length of paths.It points out that the size of padding in probed packets has a slight effect on discovering latency, and the latency with the method of bulk sending receiving is much smaller than one with the traditional traceroute. Moreover, the loss rate of packets with the technique of TTL (Time To Live) which increases monotonously is less than that with the technique of TTL which decreases monotonously. Lastly,OS (Operating System) passive fingerprint is used as heuristic to predict the length of the discovered path so as to reduce disturbance in network traffic.
文摘Securities fraud is a common worldwide problem, resulting in serious negative consequences to securities market each year. Securities Regulatory Commission from various countries has also attached great importance to the detection and prevention of securities fraud activities. Securities fraud is also increasing due to the rapid expansion of securities market in China. In accomplishing the task of securities fraud detection, China Securities Regulatory Commission (CSRC) could be facilitated in their work by using a number of data mining techniques. In this paper, we investigate the usefulness of Logistic regression model, Neural Networks (NNs), Sequential minimal optimization (SMO), Radial Basis Function (RBF) networks, Bayesian networks and Grammar Based Genet- ic Programming (GBGP) in the classification of the real, large and latest China Corporate Securities Fraud (CCSF) database. The six data mining techniques are compared in terms of their performances. As a result, we found GBGP outperforms others. This paper describes the GBGP in detail in solving the CCSF problem. In addition, the Synthetic Minority Over-sampling Technique (SMOTE) is applied to generate synthetic minority class examples for the imbalanced CCSF dataset.
文摘Li Xinfeng, a research fellow at the Chinese Academy of Social Scienc- es, served as the chief correspond- ent with the People＇s Daily in South Africa from 1998 to 2005. Li was in charge of the news coverage in the southern, eastern and central African regions and traveled across the continent, visiting over 20 AfrF can countries. His bookA Reporter＇s Exploration： Following Zheng He＇s Footsteps in Africa, marks China＇s first book on Zheng He＇s voyage to Africa, which filled the gap in the research on the history of Sino-African relations. Back in the 15th century, Zheng He, a famous Chinese admiral, sailed with his fleet as far as East Africa. Recently, Li spoke to ChinAfrica about his ex- periences in Africa as a journalist.
文摘Writers Wang Yan and Wu Fugui’s book guides Chinese readers through Sudan’s 25 states and districts as they witnessed them before the country’s split last year HOW much is actually known about arab states-particularly that of Sudan in North africa？ Looking closely at this question, it becomes clear that there is much still un
文摘1 Dinosaur Eggs in Yiwu City, Zhejiang Province In February 2017, dinosaur egg fossils were discovered in China Town part of Yiwu City, Zhejiang Province. They were confirmed by dinosaur experts from the Zhejiang Museum of Natural History to be those of Mesozoic herbivorous dinosaurs （Fig. 1）. Not long before, Yiwu Museum staff had discovered dinosaur eggs close by this place.
基金funded by the China Geological Survey Project(Grant No.DD20190098).
文摘Objective The Yanshan Fold Belt is located within the northern margin of the North China platform and contains welldeveloped and widespread Neoproterozoic and Mesoproterozoic sedimentary units with a total thickness of up to 9000 m.Previous studies identified many oil seedlings as well as asphalt and ancient hydrocarbon reservoirs in Northern Hebei depression and western Liaoning depression.This research indicates that the Mesoproterozoic and Neoproterozoic sedimentary units are ideally suited for the formation of significant oil and gas resources.The Niu D1 well was drilled by the China Geological Survey(CGS)in the Niuyingzi area and intercepted oil immersions and oil-and gas-bearing units within a limestone reservoir in the middle Proterozoic Gaoyuzhuang Formation(Fig.1).This study presents new biomarker compound and carbon isotope data that indicate that the oil within this formation was derived from hydrocarbon source rocks of the Hongshuizhuang Formation,part of the Mesoproterozoic Jixian Series,and the reservoir type is overthrust fault fractured anticline hydrocarbon reservoir.The oil reservoir within the Gaoyuzhuang Formation limestone might represent the oldest oil reservoir discovered to date within the Yanliao faulted depression zone.
基金granted by the Dinosaur Fossil Protection and Research in Pu’an Township,Yunyang County,Chongqing Program(KJ-2018035).
文摘The 2019 Annual Symposium on Yunyang Dinosaur Fossil Protection and Research was held in Chongqing on December 16,2019.It was proposed in the symposium that the dinosaurs discovered from the early Middle Jurassic Xintiangou Formation in Yunyang,Chongqing could represent a new dinosaur fauna.Previously,only a few dinosaurs have been reported from the Xintiangou Formation.Moreover,the Xintiangou dinosaurs are playing an important role in studying the evolutionary sequence of dinosaurs,and have the potential to fill the gaps during the Early-Middle dinosaur turnover.
文摘Hot Dry Rock （HDR） refers to those generally deeply buried impermeable metamorphic or crystallized biotite gneiss, granite and granodiorite rock bodies, with a burial depth greater than 2000 m, containing no water or vapor. HDR is as implied, hot and dry, with temperatures ranging from 150 to 650℃, and it can be utilized as a heat resource. Because this type of heat system does not require porosity, permeability and fluids and is widespread at the drillable depth range of 10 kin, it is thereby an infinite resource type. By contrast, thermal power generation results in copious pollution; wind power is irregular and unstable; solar energy occupies large areas.
