This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distribut...This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distributed computing, also the paper presented the status report on the effort and experiences for the implementation of a dynamic load balancing for parallel tree computation depth first search(DFS) on the cluster of a workstations project. It compared the speedup performance obtained from our platform with that obtained from the traditional one. The speedup results show that cluster of workstations can be a serious alternative to the expensive parallel machines.展开更多
A quantum BP neural networks model with learning algorithm is proposed. First, based on the universality of single qubit rotation gate and two-qubit controlled-NOT gate, a quantum neuron model is constructed, which is...A quantum BP neural networks model with learning algorithm is proposed. First, based on the universality of single qubit rotation gate and two-qubit controlled-NOT gate, a quantum neuron model is constructed, which is composed of input, phase rotation, aggregation, reversal rotation and output. In this model, the input is described by qubits, and the output is given by the probability of the state in which (1) is observed. The phase rotation and the reversal rotation are performed by the universal quantum gates. Secondly, the quantum BP neural networks model is constructed, in which the output layer and the hide layer are quantum neurons. With the application of the gradient descent algorithm, a learning algorithm of the model is proposed, and the continuity of the model is proved. It is shown that this model and algorithm are superior to the conventional BP networks in three aspects: convergence speed, convergence rate and robustness, by two application examples of pattern recognition and function approximation.展开更多
Feature extraction of range images provided by ranging sensor is a key issue of pattern recognition. To automatically extract the environmental feature sensed by a 2D ranging sensor laser scanner, an improved method b...Feature extraction of range images provided by ranging sensor is a key issue of pattern recognition. To automatically extract the environmental feature sensed by a 2D ranging sensor laser scanner, an improved method based on genetic clustering VGA-clustering is presented. By integrating the spatial neighbouring information of range data into fuzzy clustering algorithm, a weighted fuzzy clustering algorithm (WFCA) instead of standard clustering algorithm is introduced to realize feature extraction of laser scanner. Aimed at the unknown clustering number in advance, several validation index functions are used to estimate the validity of different clustering algorithms and one validation index is selected as the fitness function of genetic algorithm so as to determine the accurate clustering number automatically. At the same time, an improved genetic algorithm IVGA on the basis of VGA is proposed to solve the local optimum of clustering algorithm, which is implemented by increasing the population diversity and improving the genetic operators of elitist rule to enhance the local search capacity and to quicken the convergence speed. By the comparison with other algorithms, the effectiveness of the algorithm introduced is demonstrated.展开更多
Rewriting logic is a unified model of concurrency, which provides a formal commo n framework of well-known models of concurrent systems. A new formal method of t he specification and execution of P systems using rewri...Rewriting logic is a unified model of concurrency, which provides a formal commo n framework of well-known models of concurrent systems. A new formal method of t he specification and execution of P systems using rewriting logic was proposed. The powerful tool Ma ude 2.0 is used to implement this specification. In order to present the general ideas in a concr ete case study, a simple and classical example from the literature is adopted to present how to formally spe cify and execute a P system.展开更多
Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the m...Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the mathematical model of such a system is established. A stochastic stabilization condition for the system is given. The maximum delay can be derived from the stabilization condition.展开更多
With the spectrum extended in modern Electronic War, Laser Countermeasure Weapon will be requested in order to snatch up and keep the Electromagnetism-Power in war field. If Command, Control, Communications and Intell...With the spectrum extended in modern Electronic War, Laser Countermeasure Weapon will be requested in order to snatch up and keep the Electromagnetism-Power in war field. If Command, Control, Communications and Intelligence called Double-Army-Power-Implement is applied to general design of Laser Countermeasure Weapon System, the efficiency of Weapon System can be greatly improved. The Object-Oriented analysis and design approach based on UML for C3I system architecture was put forward, by which logical architecture described by class diagrams and behavior diagrams can be developed through Object-Oriented analysis, and physical architecture described by component diagrams and deployment diagrams can be developed through Object-Oriented design. The framework of Modeling based UML was firstly set forth, the high process of Command, Control, Intelligence, Surveillance, Reconnaissance and UML Architecture was utilized., Then the Modeling process was particularly discussed through following the core ideology and basic principle of RUP (Rational Unified Process). Next, a series of diagrams of UML diagram which include Activity diagrams, Use Case diagrams, Sequence diagrams, Package diagrams and Class diagrams of system analysis, Component diagrams, and Deployment diagrams of system design are illustrated in the process of Modeling of C3I system software. Lastly, some problems that should be noticed in the Modeling process, merit and demerit of model, next works were also put forward.展开更多
Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of onedirectional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding propert...Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of onedirectional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding properties are the basic characteristics of S-rough sets. By using the S-rough sets, the concepts of f-hiding knowledge, F-hiding knowledge, hiding degree, and hiding dependence degree are given. Then, both the hiding theorem and the hiding dependence theorem of hiding knowledge are proposed. Finally, an application of hiding knowledge is discussed.展开更多
This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after e...This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after each word and each line. When a watermarked web page is tampered, the extracted watermark can detect and locate the modifications to the web page. Besides, the framework of watermarked Web Server system was given. Compared with traditional digital signature methods, this watermarking method is more transparent in that there is no necessary to detach the watermark before displaying web pages. The e xperimental results show that the proposed scheme is an effective tool for tamper-proof of web pages.展开更多
A multicast routing algorithm of multiple QoS constraints based on widest-bandwidth (MRQW) which takes available bandwidth as the prime metric, considering the constraints of the surplus energy of the node, delay an...A multicast routing algorithm of multiple QoS constraints based on widest-bandwidth (MRQW) which takes available bandwidth as the prime metric, considering the constraints of the surplus energy of the node, delay and delay jitter, is presented. The process of routing based on MRQW is provided for as well. Correctness proof and the complexity analysis of the MRQW are also given in the paper. Simulation results show that the MRQW has a good performance in creating multicast trees. It not only satisfys multiple QoS constraints but also makes multicast links have larger available bandwidth展开更多
Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial ...Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.展开更多
Text embedded in images is one of many important cues for indexing and retrieval of images and videos. In the paper, we present a novel method of detecting text aligned either horizontally or vertically, in which a py...Text embedded in images is one of many important cues for indexing and retrieval of images and videos. In the paper, we present a novel method of detecting text aligned either horizontally or vertically, in which a pyramid structure is used to represent an image and the features of the text are extracted using SUSAN edge detector. Text regions at each level of the pyramid are identified according to the autocorrelation analysis. New techniques are introduced to split the text regions into basic ones and merge them into text lines. By evaluating the method on a set of images, we obtain a very good performance of text detection.展开更多
A novel broad concept of numbers was given out based upon the analyzing of numbers′ carrying rule. In international mathematics & computer science, all researches on numbers are only confined to same varying rule...A novel broad concept of numbers was given out based upon the analyzing of numbers′ carrying rule. In international mathematics & computer science, all researches on numbers are only confined to same varying rule of the FCN (fixed carrying numbers). The concept of VCN (variable carrying numbers) was presented, and some applied examples of practice were given out. So the engineering application of VCN for n-figures is wider than that of FCN in human society.展开更多
Community discovery of complex networks,esp.of social networks,has been a hotly debated topic in academic circles in recent years.Since actual networks usually contain some overlapping nodes that are difficult to assi...Community discovery of complex networks,esp.of social networks,has been a hotly debated topic in academic circles in recent years.Since actual networks usually contain some overlapping nodes that are difficult to assign to a certain community,overlapping community discovery is under great demand in practical applications.However,at present network community discovery is mainly done by non-overlapping community discovery methods,overlapping discovery methods are not common.In this context,an overlapping community discovery method is proposed hereby based on topological potential and specific algorithms are also provided.This method not only considers the spread of the uncertainty of community identity of the overlapping nodes in the network,but also realizes a quantified representation,i.e.,uncertainty measure,of the community identity of the overlapping nodes.The experiment results show that this method yields the results that are consistent with those by the classic methods and are more reasonable.展开更多
The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hy...The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hypothetical Trojan Horse author to be included in quantifying the relative plausibility of competing explanations for the existence of uncontested digital evidence.This new model has been applied to the case of the Trojan Horse defence( THD) against the possession of child pornography.Our results demonstrate that the THD in this case cannot be plausibly sustained unless it can be shown that an ‘off-theshelf'( OTS) Trojan Horse for this task is available and it is not detectable by the target computer,at the material time.展开更多
The security of wireless local area network (WLAN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the ...The security of wireless local area network (WLAN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEE802.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WLAN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.展开更多
Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic ...Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic fields remained open, because of the difficulty of computing class numbers of quadratic fields. In this paper, according to our researches on quadratic fields, we construct the first digital signature scheme in ideal class groups of quadratic fields, using q as modulus, which denotes the prime divisors of ideal class numbers of quadratic fields. Security of the new signature scheme is based fully on CL-DLP. This paper also investigates realization of the scheme, and proposes the concrete technique. In addition, the technique introduced in the paper can be utilized to realize signature schemes of other kinds.展开更多
Elliptic curve cryptosystem is the focus of public key cryptology nowadays, for it has many advantages RSA lacks. This paper introduced a new heuristic algorithm on computing multiple scalar multiplications of a given...Elliptic curve cryptosystem is the focus of public key cryptology nowadays, for it has many advantages RSA lacks. This paper introduced a new heuristic algorithm on computing multiple scalar multiplications of a given point. Based on this algorithm, a new method of computing scalar multiplication of elliptic curve over optimal extension field (OEF) using Frobenius map was presented. The new method is more efficient than the traditional ones. In the last part of this paper, the comparison was given in the end.展开更多
Considering the instability of data transferred existing in high speed network, a new method is proposed for improving the stability using control theory. Under this method, the mathematical model of such a network is...Considering the instability of data transferred existing in high speed network, a new method is proposed for improving the stability using control theory. Under this method, the mathematical model of such a network is established. Stability condition is derived from the mathematical model. Several simulation experiments are performed. The results show that the method can increase the stability of data transferred in terms of the congestion window, queue size, and sending rate of the source.展开更多
Ongoing research is described that is focused upon modelling the space base information network and simulating its behaviours: simulation of spaced based communications and networking project. Its objective is to dem...Ongoing research is described that is focused upon modelling the space base information network and simulating its behaviours: simulation of spaced based communications and networking project. Its objective is to demonstrate the feasibility of producing a tool that can provide a performance evaluation of various eonstellation access techniques and routing policies. The architecture and design of the simulation system are explored. The algorithm of data routing and instrument scheduling in this project is described. Besides these, the key methodologies of simulating the inter-satellite link features in the data transmissions are also discussed. The performance of both instrument scheduling algorithm and routing schemes is evaluated and analyzed through extensive simulations under a typical scenario.展开更多
基金National Science Foundation of China(No.60 173 0 3 1)
文摘This paper presented an idea to replace the traditionally expensive parallel machines by heterogeneous cluster of workstations. To emphasise the usability of cluster of workstations platform for parallel and distributed computing, also the paper presented the status report on the effort and experiences for the implementation of a dynamic load balancing for parallel tree computation depth first search(DFS) on the cluster of a workstations project. It compared the speedup performance obtained from our platform with that obtained from the traditional one. The speedup results show that cluster of workstations can be a serious alternative to the expensive parallel machines.
基金the National Natural Science Foundation of China (50138010)
文摘A quantum BP neural networks model with learning algorithm is proposed. First, based on the universality of single qubit rotation gate and two-qubit controlled-NOT gate, a quantum neuron model is constructed, which is composed of input, phase rotation, aggregation, reversal rotation and output. In this model, the input is described by qubits, and the output is given by the probability of the state in which (1) is observed. The phase rotation and the reversal rotation are performed by the universal quantum gates. Secondly, the quantum BP neural networks model is constructed, in which the output layer and the hide layer are quantum neurons. With the application of the gradient descent algorithm, a learning algorithm of the model is proposed, and the continuity of the model is proved. It is shown that this model and algorithm are superior to the conventional BP networks in three aspects: convergence speed, convergence rate and robustness, by two application examples of pattern recognition and function approximation.
基金the National Natural Science Foundation of China (60234030)the Natural Science Foundationof He’nan Educational Committee of China (2007520019, 2008B520015)Doctoral Foundation of Henan Polytechnic Universityof China (B050901, B2008-61)
文摘Feature extraction of range images provided by ranging sensor is a key issue of pattern recognition. To automatically extract the environmental feature sensed by a 2D ranging sensor laser scanner, an improved method based on genetic clustering VGA-clustering is presented. By integrating the spatial neighbouring information of range data into fuzzy clustering algorithm, a weighted fuzzy clustering algorithm (WFCA) instead of standard clustering algorithm is introduced to realize feature extraction of laser scanner. Aimed at the unknown clustering number in advance, several validation index functions are used to estimate the validity of different clustering algorithms and one validation index is selected as the fitness function of genetic algorithm so as to determine the accurate clustering number automatically. At the same time, an improved genetic algorithm IVGA on the basis of VGA is proposed to solve the local optimum of clustering algorithm, which is implemented by increasing the population diversity and improving the genetic operators of elitist rule to enhance the local search capacity and to quicken the convergence speed. By the comparison with other algorithms, the effectiveness of the algorithm introduced is demonstrated.
基金National Natural Science Foundation ofChina (No. 60173033) and 973 Project( No. 2002CB312002 ) of China, andGrand Project of the Science and Tech-nology Commission of Shanghai Munici-pality ( No. 03dz15027 and No.03dz15028)
文摘Rewriting logic is a unified model of concurrency, which provides a formal commo n framework of well-known models of concurrent systems. A new formal method of t he specification and execution of P systems using rewriting logic was proposed. The powerful tool Ma ude 2.0 is used to implement this specification. In order to present the general ideas in a concr ete case study, a simple and classical example from the literature is adopted to present how to formally spe cify and execute a P system.
基金This project was supported by the National Natural Science Foundation of China (60274014, 60574088).
文摘Considering the stochastic delay problems existing in networked control systems, a new control mode is proposed for networked control systems whose delay is longer than a sampling period. Under the control mode, the mathematical model of such a system is established. A stochastic stabilization condition for the system is given. The maximum delay can be derived from the stabilization condition.
文摘With the spectrum extended in modern Electronic War, Laser Countermeasure Weapon will be requested in order to snatch up and keep the Electromagnetism-Power in war field. If Command, Control, Communications and Intelligence called Double-Army-Power-Implement is applied to general design of Laser Countermeasure Weapon System, the efficiency of Weapon System can be greatly improved. The Object-Oriented analysis and design approach based on UML for C3I system architecture was put forward, by which logical architecture described by class diagrams and behavior diagrams can be developed through Object-Oriented analysis, and physical architecture described by component diagrams and deployment diagrams can be developed through Object-Oriented design. The framework of Modeling based UML was firstly set forth, the high process of Command, Control, Intelligence, Surveillance, Reconnaissance and UML Architecture was utilized., Then the Modeling process was particularly discussed through following the core ideology and basic principle of RUP (Rational Unified Process). Next, a series of diagrams of UML diagram which include Activity diagrams, Use Case diagrams, Sequence diagrams, Package diagrams and Class diagrams of system analysis, Component diagrams, and Deployment diagrams of system design are illustrated in the process of Modeling of C3I system software. Lastly, some problems that should be noticed in the Modeling process, merit and demerit of model, next works were also put forward.
基金supported by the National Natural Science Foundation of China (60364001,70461001)the Hainan Provincial Natural Science Foundation of China (807054)Hainan Provincial Education Office Foundation (HJ 2008-56)
文摘Singular rough sets (S-rough sets) have three classes of forms: one-directional S-rough sets, dual of onedirectional S-rough sets, and two-directional S-rough sets. Dynamic, hereditary, mnemonic, and hiding properties are the basic characteristics of S-rough sets. By using the S-rough sets, the concepts of f-hiding knowledge, F-hiding knowledge, hiding degree, and hiding dependence degree are given. Then, both the hiding theorem and the hiding dependence theorem of hiding knowledge are proposed. Finally, an application of hiding knowledge is discussed.
文摘This paper proposed a watermarking algorithm for tamper-proof of web pages. For a web page, it generates a watermark consisting of a sequence of Space and Tab. The wa termark is then embedded into the web page after each word and each line. When a watermarked web page is tampered, the extracted watermark can detect and locate the modifications to the web page. Besides, the framework of watermarked Web Server system was given. Compared with traditional digital signature methods, this watermarking method is more transparent in that there is no necessary to detach the watermark before displaying web pages. The e xperimental results show that the proposed scheme is an effective tool for tamper-proof of web pages.
基金This project was supported by the National Natural Science Foundation of China (90304018)and the Natural ScienceFoundation of Hubei Province of China (2004ABA023)
文摘A multicast routing algorithm of multiple QoS constraints based on widest-bandwidth (MRQW) which takes available bandwidth as the prime metric, considering the constraints of the surplus energy of the node, delay and delay jitter, is presented. The process of routing based on MRQW is provided for as well. Correctness proof and the complexity analysis of the MRQW are also given in the paper. Simulation results show that the MRQW has a good performance in creating multicast trees. It not only satisfys multiple QoS constraints but also makes multicast links have larger available bandwidth
文摘Broadcasting is an important operation and been widely used in wireless sensor networks (WSNs). These networks are power constrained as nodes operate with limited battery power. Wireless sensor networks are spatial graphs that have much more clustered and much high path-length characteristics. After considering energy- efficient broadcasting in such networks, by combining the small-world characteristic of WSNs and the properties of ant algorithm to quickly identify an optimal path, small-world power-aware broadcast algorithm is introduced and evaluated. Given different densities of network, simulation results show that our algorithm significantly improves life of networks and also reduces communication distances and power consumption.
文摘Text embedded in images is one of many important cues for indexing and retrieval of images and videos. In the paper, we present a novel method of detecting text aligned either horizontally or vertically, in which a pyramid structure is used to represent an image and the features of the text are extracted using SUSAN edge detector. Text regions at each level of the pyramid are identified according to the autocorrelation analysis. New techniques are introduced to split the text regions into basic ones and merge them into text lines. By evaluating the method on a set of images, we obtain a very good performance of text detection.
基金This research is supported by the Nature Science Foundation of Fujian Province of China(item No.2006J0414foundation No.A0640015)
文摘A novel broad concept of numbers was given out based upon the analyzing of numbers′ carrying rule. In international mathematics & computer science, all researches on numbers are only confined to same varying rule of the FCN (fixed carrying numbers). The concept of VCN (variable carrying numbers) was presented, and some applied examples of practice were given out. So the engineering application of VCN for n-figures is wider than that of FCN in human society.
基金Sponsored by the National Natural Science Foundation of China(Grant No.61073041,60873037,61100008 and 61073043)the Natural Science Foundation of Heilongjiang Province(Grant No.F200901 and F201023)+1 种基金the Harbin Special Funds for Technological Innovation Research(Grant No. 2010RFXXG002 and 2011RFXXG015)the Fundamental Research Funds for the Central Universities of China(Grant No.HEUCF100602)
文摘Community discovery of complex networks,esp.of social networks,has been a hotly debated topic in academic circles in recent years.Since actual networks usually contain some overlapping nodes that are difficult to assign to a certain community,overlapping community discovery is under great demand in practical applications.However,at present network community discovery is mainly done by non-overlapping community discovery methods,overlapping discovery methods are not common.In this context,an overlapping community discovery method is proposed hereby based on topological potential and specific algorithms are also provided.This method not only considers the spread of the uncertainty of community identity of the overlapping nodes in the network,but also realizes a quantified representation,i.e.,uncertainty measure,of the community identity of the overlapping nodes.The experiment results show that this method yields the results that are consistent with those by the classic methods and are more reasonable.
文摘The Enhanced Complexity Model( ECM) developed previously has been further extended to produce a Motivationally Enhanced Complexity Model( MECM) which enables the degree of motivation,capability and opportunity of a hypothetical Trojan Horse author to be included in quantifying the relative plausibility of competing explanations for the existence of uncontested digital evidence.This new model has been applied to the case of the Trojan Horse defence( THD) against the possession of child pornography.Our results demonstrate that the THD in this case cannot be plausibly sustained unless it can be shown that an ‘off-theshelf'( OTS) Trojan Horse for this task is available and it is not detectable by the target computer,at the material time.
基金The National Natural Science Foundation ofChina(No60703031)The Natural Science Foundation of Shaanxi Province ( No2007F50)
文摘The security of wireless local area network (WLAN) becomes a bottleneck for its further applications. At present, many standard organizations and manufacturers of WLAN try to solve this problem. However, owing to the serious secure leak in IEEE802.11 standards, it is impossible to utterly solve the problem by simply adding some remedies. Based on the analysis on the security mechanism of WLAN and the latest techniques of WLAN security, a solution to WLAN security was presented. The solution makes preparation for the further combination of WLAN and Internet.
文摘Quadratic-field cryptosystem is a cryptosystem built from discrete logarithm problem in ideal class groups of quadratic fields(CL-DLP). The problem on digital signature scheme based on ideal class groups of quadratic fields remained open, because of the difficulty of computing class numbers of quadratic fields. In this paper, according to our researches on quadratic fields, we construct the first digital signature scheme in ideal class groups of quadratic fields, using q as modulus, which denotes the prime divisors of ideal class numbers of quadratic fields. Security of the new signature scheme is based fully on CL-DLP. This paper also investigates realization of the scheme, and proposes the concrete technique. In addition, the technique introduced in the paper can be utilized to realize signature schemes of other kinds.
文摘Elliptic curve cryptosystem is the focus of public key cryptology nowadays, for it has many advantages RSA lacks. This paper introduced a new heuristic algorithm on computing multiple scalar multiplications of a given point. Based on this algorithm, a new method of computing scalar multiplication of elliptic curve over optimal extension field (OEF) using Frobenius map was presented. The new method is more efficient than the traditional ones. In the last part of this paper, the comparison was given in the end.
基金the National Natural Science Foundation of China (50579022 50539140).
文摘Considering the instability of data transferred existing in high speed network, a new method is proposed for improving the stability using control theory. Under this method, the mathematical model of such a network is established. Stability condition is derived from the mathematical model. Several simulation experiments are performed. The results show that the method can increase the stability of data transferred in terms of the congestion window, queue size, and sending rate of the source.
基金This project was supported by the National "863" High-Tech Research and Development Program of China(2002AA7170)
文摘Ongoing research is described that is focused upon modelling the space base information network and simulating its behaviours: simulation of spaced based communications and networking project. Its objective is to demonstrate the feasibility of producing a tool that can provide a performance evaluation of various eonstellation access techniques and routing policies. The architecture and design of the simulation system are explored. The algorithm of data routing and instrument scheduling in this project is described. Besides these, the key methodologies of simulating the inter-satellite link features in the data transmissions are also discussed. The performance of both instrument scheduling algorithm and routing schemes is evaluated and analyzed through extensive simulations under a typical scenario.