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Distributed Information Flow Verification for Secure Service Composition in Smart Sensor Network 被引量:3
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作者 XI Ning SUN Cong +2 位作者 MA Jianfeng CHEN Xiaofeng SHEN Yulong 《China Communications》 SCIE CSCD 2016年第4期119-130,共12页
Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, dif... Accelerate processor, efficient software and pervasive connections provide sensor nodes with more powerful computation and storage ability, which can offer various services to user. Based on these atomic services, different sensor nodes can cooperate and compose with each other to complete more complicated tasks for user. However, because of the regional characteristic of sensor nodes, merging data with different sensitivities become a primary requirement to the composite services, and information flow security should be intensively considered during service composition. In order to mitigate the great cost caused by the complexity of modeling and the heavy load of single-node verification to the energy-limited sensor node, in this paper, we propose a new distributed verification framework to enforce information flow security on composite services of smart sensor network. We analyze the information flows in composite services and specify security constraints for each service participant. Then we propose an algorithm over the distributed verification framework involving each sensor node to participate in the composite service verification based on the security constraints. The experimental results indicate that our approach can reduce the cost of verification and provide a better load balance. 展开更多
关键词 information flow security service composition formal verification smart sensor network
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Information Flow Security Models for Cloud Computing 被引量:3
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作者 Congdong Lv Ji Zhang +1 位作者 Zhoubao Sun Gang Qian 《Computers, Materials & Continua》 SCIE EI 2020年第12期2687-2705,共19页
Cloud computing provides services to users through Internet.This open mode not only facilitates the access by users,but also brings potential security risks.In cloud computing,the risk of data leakage exists between u... Cloud computing provides services to users through Internet.This open mode not only facilitates the access by users,but also brings potential security risks.In cloud computing,the risk of data leakage exists between users and virtual machines.Whether direct or indirect data leakage,it can be regarded as illegal information flow.Methods,such as access control models can control the information flow,but not the covert information flow.Therefore,it needs to use the noninterference models to detect the existence of illegal information flow in cloud computing architecture.Typical noninterference models are not suitable to certificate information flow in cloud computing architecture.In this paper,we propose several information flow models for cloud architecture.One model is for transitive cloud computing architecture.The others are for intransitive cloud computing architecture.When concurrent access actions execute in the cloud architecture,we want that security domain and security domain do not affect each other,that there is no information flow between security domains.But in fact,there will be more or less indirect information flow between security domains.Our models are concerned with how much information is allowed to flow.For example,in the CIP model,the other domain can learn the sequence of actions.But in the CTA model,the other domain can’t learn the information.Which security model will be used in an architecture depends on the security requirements for that architecture. 展开更多
关键词 Cloud computing security information flow security NONINTERFERENCE noninterference models
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A Multi-Flow Information Flow Tracking Approach for Proving Quantitative Hardware Security Properties 被引量:2
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作者 Yu Tai Wei Hu +2 位作者 Lu Zhang Dejun Mu Ryan Kastner 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2021年第1期62-71,共10页
Information Flow Tracking(IFT)is an established formal method for proving security properties related to confidentiality,integrity,and isolation.It has seen promise in identifying security vulnerabilities resulting fr... Information Flow Tracking(IFT)is an established formal method for proving security properties related to confidentiality,integrity,and isolation.It has seen promise in identifying security vulnerabilities resulting from design flaws,timing channels,and hardware Trojans for secure hardware design.However,existing IFT methods tend to take a qualitative approach and only enforce binary security properties,requiring strict non-interference for the properties to hold while real systems usually allow a small amount of information flows to enable desirable interactions.Consequently,existing methods are inadequate for reasoning about quantitative security properties or measuring the security of a design in order to assess the severity of a security vulnerability.In this work,we propose two multi-flow solutions—multiple verifications for replicating existing IFT model and multi-flow IFT method.The proposed multi-flow IFT method provides more insight into simultaneous information flow behaviors and allows for proof of quantitative information flow security properties,such as diffusion,randomization,and boundaries on the amount of simultaneous information flows.Experimental results show that our method can be used to prove a new type of information flow security property with verification performance benefits. 展开更多
关键词 hardware security information flow Tracking(IFT) multi-flow IFT security property
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Information Flow Scheduling in Concurrent Multi-Product Development Based on DSM 被引量:1
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作者 Qing-Chao Sun Wei-Qiang Huang +1 位作者 Ying-Jie Jiang Wei Sun 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第5期1101-1111,共11页
Multi-product collaborative development is adopted widely in manufacturing enterprise, while the present multi-project planning models don't take techni- cal/data interactions of multiple products into account. To de... Multi-product collaborative development is adopted widely in manufacturing enterprise, while the present multi-project planning models don't take techni- cal/data interactions of multiple products into account. To decrease the influence of technical/data interactions on project progresses, the information flow scheduling models based on the extended DSM is presented. Firstly, infor- mation dependencies are divided into four types: series, parallel, coupling and similar. Secondly, different types of dependencies are expressed as DSM units, and the exten- ded DSM model is brought forward, described as a block matrix. Furthermore, the information flow scheduling methods is proposed, which involves four types of opera- tions, where partitioning and clustering algorithm are modified from DSM for ensuring progress of high-priority project, merging and converting is the specific computation of the extended DSM. Finally, the information flow scheduling of two machine tools development is analyzed with example, and different project priorities correspond to different task sequences and total coordination cost. The proposed methodology provides a detailed instruction for information flow scheduling in multi-product development, with specially concerning technical/data interactions. 展开更多
关键词 Concurrent multi-product development information flow planning Extended DSM Projectpriority
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Evolving a Bayesian network model with information flow for time series interpolation of multiple ocean variables 被引量:1
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作者 Ming Li Ren Zhang Kefeng Liu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2021年第7期249-262,共14页
Based on Bayesian network (BN) and information flow (IF),a new machine learning-based model named IFBN is put forward to interpolate missing time series of multiple ocean variables. An improved BN structural learning ... Based on Bayesian network (BN) and information flow (IF),a new machine learning-based model named IFBN is put forward to interpolate missing time series of multiple ocean variables. An improved BN structural learning algorithm with IF is designed to mine causal relationships among ocean variables to build network structure. Nondirectional inference mechanism of BN is applied to achieve the synchronous interpolation of multiple missing time series. With the IFBN,all ocean variables are placed in a causal network visually,making full use of information about related variables to fill missing data. More importantly,the synchronous interpolation of multiple variables can avoid model retraining when interpolative objects change. Interpolation experiments show that IFBN has even better interpolation accuracy,effectiveness and stability than existing methods. 展开更多
关键词 Bayesian network information flow time series interpolation ocean variables
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The Information Flow Analyzing Based on CPC 被引量:1
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作者 张璋 李辉 《Journal of Electronic Science and Technology of China》 2005年第4期377-379,共3页
The information flow chart within product life cycle is given out based on collaborative production commerce (CPC) thoughts. In this chart, the separated information systems are integrated by means of enterprise kno... The information flow chart within product life cycle is given out based on collaborative production commerce (CPC) thoughts. In this chart, the separated information systems are integrated by means of enterprise knowledge assets that are promoted by CPC from production knowledge. The information flow in R&D process is analyzed in the environment of virtual R&D group and distributed PDM. In addition, the information flow throughout the manufacturing and marketing process is analyzed in CPC environment. 展开更多
关键词 information flow collaborative production commerce PDM
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DuFNet:Dual Flow Network of Real-Time Semantic Segmentation for Unmanned Driving Application of Internet of Things 被引量:1
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作者 Tao Duan Yue Liu +2 位作者 Jingze Li Zhichao Lian d Qianmu Li 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第7期223-239,共17页
The application of unmanned driving in the Internet of Things is one of the concrete manifestations of the application of artificial intelligence technology.Image semantic segmentation can help the unmanned driving sy... The application of unmanned driving in the Internet of Things is one of the concrete manifestations of the application of artificial intelligence technology.Image semantic segmentation can help the unmanned driving system by achieving road accessibility analysis.Semantic segmentation is also a challenging technology for image understanding and scene parsing.We focused on the challenging task of real-time semantic segmentation in this paper.In this paper,we proposed a novel fast architecture for real-time semantic segmentation named DuFNet.Starting from the existing work of Bilateral Segmentation Network(BiSeNet),DuFNet proposes a novel Semantic Information Flow(SIF)structure for context information and a novel Fringe Information Flow(FIF)structure for spatial information.We also proposed two kinds of SIF with cascaded and paralleled structures,respectively.The SIF encodes the input stage by stage in the ResNet18 backbone and provides context information for the feature fusionmodule.Features from previous stages usually contain rich low-level details but high-level semantics for later stages.Themultiple convolutions embed in Parallel SIF aggregate the corresponding features among different stages and generate a powerful global context representation with less computational cost.The FIF consists of a pooling layer and an upsampling operator followed by projection convolution layer.The concise component provides more spatial details for the network.Compared with BiSeNet,our work achieved faster speed and comparable performance with 72.34%mIoU accuracy and 78 FPS on Cityscapes Dataset based on the ResNet18 backbone. 展开更多
关键词 Real-time semantic segmentation convolutional neural network feature fusion unmanned driving fringe information flow
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Functional connectivity and information flow in cerebral motor regions of healthy people following finger movement training
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作者 Zeqiang Yang Dongmei Hao Ying Li Yanping Bai 《Neural Regeneration Research》 SCIE CAS CSCD 2010年第9期710-714,共5页
BACKGROUND:Neuro-rehabilitative training has been shown to promote motor function recovery in stroke patients,although the underlying mechanisms have not been fully clarified.OBJECTIVE:To investigate the effects of ... BACKGROUND:Neuro-rehabilitative training has been shown to promote motor function recovery in stroke patients,although the underlying mechanisms have not been fully clarified.OBJECTIVE:To investigate the effects of finger movement training on functional connectivity and information flow direction in cerebral motor areas of healthy people using electroencephalogram (EEG).DESIGN,TIME AND SETTING:A self-controlled,observational study was performed at the College of Life Science and Bioengineering,Beijing University of Technology between December 2008 and April 2009.PARTICIPANTS:Nineteen healthy adults,who seldom played musical instruments or keyboards,were included in the present study.METHODS:Specific finger movement training was performed,and all subjects were asked to separately press keys with their left or right hand fingers,according to instructions.The task comprised five sessions of test train test train-test.Thirty-six channel EEG signals were recorded in different test sessions prior to and after training.Data were statistically analyzed using one-way analysis of variance.MAIN OUTCOME MEASURES:The number of effective performances,correct ratio,average response time,average movement time,correlation coefficient between pairs of EEG channels,and information flow direction in motor regions were analyzed and compared between different training sessions.RESULTS:Motor function of all subjects was significantly improved in the third test comparedwith the first test (P〈 0.01).More than 80% of connections were strengthened in the motor-related areas following two training sessions,in particular the primary motor regions under the C4 electrode.Compared to the first test,a greater amount of information flowed from the Cz and Fcz electrodes (corresponding to supplementary motor area) to the C4 electrode in the third test.CONCLUSION:Finger task training increased motor ability in subjects by strengthening connections and changing information flow in the motor areas.These results provided a greater understanding of the mechanisms involved in motor rehabilitation. 展开更多
关键词 motor cortex functional connectivity information flow direction ELECTROENCEPHALOGRAM
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Enhance Information Flow Tracking with Function Recognition
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作者 Zhou Kan Huang Shiqiu +3 位作者 Huang Shan Qi Zhengwei Gu Jian Guan Haibing 《China Communications》 SCIE CSCD 2010年第6期24-29,共6页
With the spread use of the computers, a new crime space and method are presented for criminals. Thus computer evidence plays a key part in criminal cases. Traditional computer evidence searches require that the comput... With the spread use of the computers, a new crime space and method are presented for criminals. Thus computer evidence plays a key part in criminal cases. Traditional computer evidence searches require that the computer specialists know what is stored in the given computer. Binary-based information flow tracking which concerns the changes of control flow is an effective way to analyze the behavior of a program. The existing systems ignore the modifications of the data flow, which may be also a malicious behavior. Thus the function recognition is introduced to improve the information flow tracking. Function recognition is a helpful technique recognizing the function body from the software binary to analyze the binary code. And that no false positive and no false negative in our experiments strongly proves that our approach is effective. 展开更多
关键词 function recognition information flow tracking program behavior e-evidence.
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Highway Transport Development Strategy Based on Information Flow Impact
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作者 ShengZhao Shumin Wang 《Chinese Business Review》 2004年第9期58-61,共4页
The characteristics of highway transport and the application of information technology in highway transport service are combined; the information flows' promotion and substitution on highway transport are analyzed; a... The characteristics of highway transport and the application of information technology in highway transport service are combined; the information flows' promotion and substitution on highway transport are analyzed; and the highway transport development strategy based on information flow impact is proposed. 展开更多
关键词 highway transport information flow information technology development strategy
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Performance Improvement in Manufacturing Shop Floor Operations of Developing Countries Based on Three Characteristics of Information Flow
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作者 Joseph Voufo André Marie Mbakop +3 位作者 Florent Biyeme Rolland Djomi Pélagie Flore Nanfack Temgoua Jean Raymond Lucien Meva’a 《Journal of Computer and Communications》 2022年第3期46-65,共20页
The management of information flow for production improvement has always been a target in the research. In this paper, the focus is on the analysis model of the characteristics of information flow in shop floor operat... The management of information flow for production improvement has always been a target in the research. In this paper, the focus is on the analysis model of the characteristics of information flow in shop floor operations based on the influence that dimension (support or medium), direction and the quality information flow have on the value of information flow using machine learning classification algorithms. The obtained results of classification algorithms used to analyze the value of information flow are Decision Trees (DT) and Random Forest (RF) with a score of 0.99% and the mean absolute error of 0.005. The results also show that the management of information flow using DT or RF shows that, the dimension of information such as digital information has the greatest value of information flow in shop floor operations when the shop floor is totally digitalized. Direction of information flow does not have any great influence on shop floor operations processes when the operations processes are digitalized or done by operators as machines. 展开更多
关键词 Developing Countries information flow Characteristics Machine Learning Shop Floor Operations Value of information flow
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A time sequence analysis on the informal information flow mechanism of microblogging
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作者 Yuan HU Xiaoli LIAO Andong WU 《Chinese Journal of Library and Information Science》 2011年第Z1期68-81,共14页
Microblog is a new Internet featured product, which has seen a rapid development in recent years. Researchers from different countries are making various technical analyses on microblogging applications. In this study... Microblog is a new Internet featured product, which has seen a rapid development in recent years. Researchers from different countries are making various technical analyses on microblogging applications. In this study, through using the natural language processing(NLP) and data mining, we analyzed the information content transmitted via a microblog, users' social networks and their interactions, and carried out an empirical analysis on the dissemination process of one particular piece of information via Sina Weibo.Based on the result of these analyses, we attempt to develop a better understanding about the rule and mechanism of the informal information flow in microblogging. 展开更多
关键词 Microblog information flow model Social network information dissemination
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The Immense Impact of Reverse Edges on Large Hierarchical Networks
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作者 Haosen Cao Bin-Bin Hu +7 位作者 Xiaoyu Mo Duxin Chen Jianxi Gao Ye Yuan Guanrong Chen Tamás Vicsek Xiaohong Guan Hai-Tao Zhang 《Engineering》 SCIE EI CAS CSCD 2024年第5期240-249,共10页
Hierarchical networks are frequently encountered in animal groups,gene networks,and artificial engineering systems such as multiple robots,unmanned vehicle systems,smart grids,wind farm networks,and so forth.The struc... Hierarchical networks are frequently encountered in animal groups,gene networks,and artificial engineering systems such as multiple robots,unmanned vehicle systems,smart grids,wind farm networks,and so forth.The structure of a large directed hierarchical network is often strongly influenced by reverse edges from lower-to higher-level nodes,such as lagging birds’howl in a flock or the opinions of lowerlevel individuals feeding back to higher-level ones in a social group.This study reveals that,for most large-scale real hierarchical networks,the majority of the reverse edges do not affect the synchronization process of the entire network;the synchronization process is influenced only by a small part of these reverse edges along specific paths.More surprisingly,a single effective reverse edge can slow down the synchronization of a huge hierarchical network by over 60%.The effect of such edges depends not on the network size but only on the average in-degree of the involved subnetwork.The overwhelming majority of active reverse edges turn out to have some kind of“bunching”effect on the information flows of hierarchical networks,which slows down synchronization processes.This finding refines the current understanding of the role of reverse edges in many natural,social,and engineering hierarchical networks,which might be beneficial for precisely tuning the synchronization rhythms of these networks.Our study also proposes an effective way to attack a hierarchical network by adding a malicious reverse edge to it and provides some guidance for protecting a network by screening out the specific small proportion of vulnerable nodes. 展开更多
关键词 SYNCHRONIZABILITY Large hierarchical networks Reverse edges information flows Complex networks
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May Protein Be as the Genetic Information Carrier?
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作者 刘次全 黄京飞 王莹 《Zoological Research》 CAS CSCD 1993年第S1期128-139,152,共13页
The 'central dogma 'of molecular biology indicated that the direction of the genetic information flow is from DNA - RNA - protein. However, up to now, the central dogma has not obtained a sufficient theoretica... The 'central dogma 'of molecular biology indicated that the direction of the genetic information flow is from DNA - RNA - protein. However, up to now, the central dogma has not obtained a sufficient theoretical support from cybernetics and information theory. In addition, some special cases in biology, such as, although the scrapie prion is irreversibly inactivated by alkali, five procedures with more specificity for modifying nucleic acids failed to cause inactivation and when a resting cell is activated by some factors and division occurs, protein synthesis has begun before DNA synthesis etc., are also very difficult to explain clearly by the central dogma. A broad outline of a mechanism for reverse translation can easily be 'designed', based on the normal translation process, and this serves both to prove that there is no fundamental theoretical reason for the central dogma, and to illustrate why the redundancy of genetic code is not a problem.This paper, based on some previous research work of authors, from the view of cybernetics, information theory and theoretical biology, explored the possibility of protein as a genetic information carrier, the probable pairing ways between ammo acids-codons, and the direction of genetic information flows etc., at theory, by comparing and analyzing theoretically the characteristics of information carriers existing in DNA and protein. The authors inferred that perhaps protein may join the informational transferring as a genetic information carrier; the direction of genetic information flows, besides the way described by the central dogma, seem also to have another type, that is, genetic information flowing from protein - DNA (RNA) - protein, which also includes the genetic information flow in the central dogma. Undoubtedly, the research on problems about the position and roles of protein during the genetic information transferring will have an important effect on the investigation and development of molecular biology, molecular genetics and gene engineering. 展开更多
关键词 Genetic information flows Central dogma information carrier information transfer
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Impacts of central-Pacific El Niño and physical drivers on eastern Pacific bigeye tuna
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作者 Peng LIAN Le GAO 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第3期972-987,共16页
Bigeye tuna Thunnus obesus is an important migratory species that forages deeply,and El Niño events highly influence its distribution in the eastern Pacific Ocean.While sea surface temperature is widely recognize... Bigeye tuna Thunnus obesus is an important migratory species that forages deeply,and El Niño events highly influence its distribution in the eastern Pacific Ocean.While sea surface temperature is widely recognized as the main factor affecting bigeye tuna(BET)distribution during El Niño events,the roles of different types of El Niño and subsurface oceanic signals,such as ocean heat content and mixed layer depth,remain unclear.We conducted A spatial-temporal analysis to investigate the relationship among BET distribution,El Niño events,and the underlying oceanic signals to address this knowledge gap.We used monthly purse seine fisheries data of BET in the eastern tropical Pacific Ocean(ETPO)from 1994 to 2012 and extracted the central-Pacific El Niño(CPEN)indices based on Niño 3 and Niño 4indexes.Furthermore,we employed Explainable Artificial Intelligence(XAI)models to identify the main patterns and feature importance of the six environmental variables and used information flow analysis to determine the causality between the selected factors and BET distribution.Finally,we analyzed Argo datasets to calculate the vertical,horizontal,and zonal mean temperature differences during CPEN and normal years to clarify the oceanic thermodynamic structure differences between the two types of years.Our findings reveal that BET distribution during the CPEN years is mainly driven by advection feedback of subsurface warmer thermal signals and vertically warmer habitats in the CPEN domain area,especially in high-yield fishing areas.The high frequency of CPEN events will likely lead to the westward shift of fisheries centers. 展开更多
关键词 bigeye tuna central-Pacific El Niño(CPEN) ocean heat content ARGO explainable artificial intelligence(XAI) information flow
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Debris flow susceptibility analysis based on the combined impacts of antecedent earthquakes and droughts: a case study for cascade hydropower stations in the upper Yangtze River, China 被引量:4
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作者 HU Gui-sheng CHEN Ning-sheng +3 位作者 TANOLI Javed Iqbal LIU Mei LIU Rong-Kun CHEN Kun-Ting 《Journal of Mountain Science》 SCIE CSCD 2017年第9期1712-1727,共16页
The upper Yangtze River region is one of the most frequent debris flow areas in China. The study area contains a cascade of six large hydropower stations located along the river with total capacity of more than 70 mil... The upper Yangtze River region is one of the most frequent debris flow areas in China. The study area contains a cascade of six large hydropower stations located along the river with total capacity of more than 70 million kilowatts. The purpose of the study was to determine potential and dynamic differences in debris flow susceptibility and intensity with regard to seasonal monsoon events. We analyzed this region's debris flow history by examining the effective peak acceleration of antecedent earthquakes,the impacts of antecedent droughts, the combined effects of earthquakes and droughts, with regard to topography, precipitation, and loose solid material conditions. Based on these factors, we developed a debris flow susceptibility map. Results indicate that the entire debris flow susceptibility area is 167,500 km^2, of which 26,800 km^2 falls within the high susceptibility area, with 60,900 km^2 in medium and 79,800 km^2 are in low susceptibility areas. Three of the six large hydropower stations are located within the areas with high risk of debris flows. The synthetic zonation map of debris flow susceptibility for the study area corresponds with both the investigation data and actual distribution of debris flows. The results of debris flow susceptibility provide base-line data for mitigating, assessing, controlling and monitoring of debris flows hazards. 展开更多
关键词 Hydropower stations Debris flow susceptibility Earthquake Drought Geological information System(GIS) Upper Yangtze River
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Measuring the Evolution and Influence in Society’s Information Networks
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作者 Xiaocun Mao Tingting Dong +1 位作者 Meng Li Zhenping Li 《Journal of Applied Mathematics and Physics》 2016年第4期677-685,共9页
We develop a series of mathematical models to describe flow of information in different periods of time and the relationship between flow of information and inherent value. We optimize the diffusion mechanism of infor... We develop a series of mathematical models to describe flow of information in different periods of time and the relationship between flow of information and inherent value. We optimize the diffusion mechanism of information based on model SEIR and improve the diffusion mechanism. In order to explore how inherent value of the information affects the flow of information, we simulate the model by using Matalab. We also use the data that the number of people is connected to Internet in Canada from the year 2009 to 2014 to analysis the model’s reliability. Then we use the model to predict the communication networks’ relationships and capacities around the year 2050. Last we do sensitivity analysis by making small changes in parameters of simulation experiment. The result of the experiment is helpful to model how public interest and opinion can be changed in complex network. 展开更多
关键词 flow of information SEIR Model Dynamic Equations Complex Network
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Impact of trading hours extensions on foreign exchange volatility:intraday evidence from the Moscow exchange
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作者 Michael Frommel Eyup Kadioglu 《Financial Innovation》 2023年第1期2729-2751,共23页
Using transaction-level tick-by-tick data of same-and next-day settlement of the Russian Ruble versus the US Dollar exchange rate(RUB/USD)traded on the Moscow Exchange Market during the period 2005–2013,we analyze th... Using transaction-level tick-by-tick data of same-and next-day settlement of the Russian Ruble versus the US Dollar exchange rate(RUB/USD)traded on the Moscow Exchange Market during the period 2005–2013,we analyze the impact of trading hours extensions on volatility.During the sample period,the Moscow Exchange extended trading hours three times for the same-day settlement and two times for the next-day settlement of the RUB/USD rate.To analyze the effect of the implementations,various measures of historical and realized volatility are calculated for 5-and 15-min intraday intervals spanning a period of three months both prior to and following trading hours extensions.Besides historical volatility measures,we also examine volume and spread.We apply an autoregressive moving average-autoregressive conditional heteroscedasticity(ARMA-GARCH)model utilizing realized volatility and a trade classification rule to estimate the probability of informed trading.The extensions of trading hours cause a significant increase in both volatility and volume for further analyzing the reasons behind volatility changes.Volatility changes mostly occur after the opening of the market.The length of the extension has a significant positive effect on realized volatility.The results indicate that informed trading increased substantially after the opening for the rate of same-day settlement,whereas this is not observed for next-day settlement.Although trading hours extensions raise opportunities for more transactions and liquidity in foreign exchange markets,they may also lead to higher volatility in the market.Furthermore,this distortion is more significant at opening and midday.A potential explanation for the increased volatility mostly at the opening is that the trading hours extension attracts informed traders rather than liquidity providers. 展开更多
关键词 VOLATILITY Trading hours extension Foreign exchange market Informed trading Volume Spread Market overlap information flow
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电子商务条件下的铁路货运物流信息化研究 被引量:6
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作者 牛忠海 贾元华 +2 位作者 张文学 张东华 钟江 《铁道货运》 2015年第2期1-6,共6页
物流信息化可以优化物流管理模式,降低物流成本,提高物流企业工作效率,增强企业的市场竞争力,是现代物流发展的必然要求和基石。研究电子商务条件下的铁路物流业务流程信息化改造,并依托既有电子商务平台及TMIS等数据系统,设计能够满足... 物流信息化可以优化物流管理模式,降低物流成本,提高物流企业工作效率,增强企业的市场竞争力,是现代物流发展的必然要求和基石。研究电子商务条件下的铁路物流业务流程信息化改造,并依托既有电子商务平台及TMIS等数据系统,设计能够满足物流业务数据集成、作业流程管理智能化的铁路物流管理信息系统,以加快铁路物流信息化发展,实现铁路物流智能化辅助决策。 展开更多
关键词 电子商务 铁路物流 业务流程 信息化
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林业网格化管理系统模型及实现的研究 被引量:3
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作者 吴东亮 张旸 +1 位作者 薛波 唐小明 《北京林业大学学报》 CAS CSCD 北大核心 2007年第S2期18-21,共4页
该文以我国林业管理一般原型的林业信息化为基础,将网格的概念引入到林业信息化管理中,从一个典型的业务流程出发,提出了一种新的林业网格化管理模型.该模型将业务模型和行政管理模型结合起来,打破了原有各部门各自封闭的局面,构造一个... 该文以我国林业管理一般原型的林业信息化为基础,将网格的概念引入到林业信息化管理中,从一个典型的业务流程出发,提出了一种新的林业网格化管理模型.该模型将业务模型和行政管理模型结合起来,打破了原有各部门各自封闭的局面,构造一个由绿色资源网格、信息采集、数据网格、业务建模与协同,以及考核评价等系统组成的林业网格化管理框架.同时,为了实现这种网格化管理,该文从信息技术的系统层面上,引入了基于LDAP目录服务元数据管理的数据网格和网格监控技术,作为底层技术支持,将业务建模和协同平台作为其他应用系统的一种基础平台. 展开更多
关键词 信息化 网格 业务流程 系统模型 元数据
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