软件定义自组网(Software Defined Mobile Ad Hoc Network,SD-MANET)融合了软件定义网络(Software Defined Network,SDN)集中控制优势和移动自组网(Mobile Ad Hoc Network,MANET)的动态组网优势,但Mininet等现有仿真平台在动态拓扑与扩...软件定义自组网(Software Defined Mobile Ad Hoc Network,SD-MANET)融合了软件定义网络(Software Defined Network,SDN)集中控制优势和移动自组网(Mobile Ad Hoc Network,MANET)的动态组网优势,但Mininet等现有仿真平台在动态拓扑与扩展性等方面存在显著局限,严重制约了其关键算法的研究。针对这一问题,提出基于网络模拟器-3(Network Simulator-3,NS-3)的仿真平台NS3-SDMANET,具体工作包括:基于NS-3框架实现了SD-MANET网络层关键特性的仿真;基于远程过程调用对平台功能进行封装,并提供可编程接口。战术网的测试案例表明:NS3-SDMANET在SD-MANET网络层关键特性仿真方面表现优异,能够有效支撑SD-MANET网络层算法的高效验证与性能评估,为相关研究提供了高扩展性的基础仿真环境。展开更多
MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them a...MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them are highly conserved. With the miRNA roles identified in nearly all aspects of biological processes, evidence is mounting that miRNAs could represent a new layer of regulatory network, and their regulatory effect might be much more pervasive than previously suspected. Here we focus on the posttranscriptional level gene regulation of miRNAs in animals and review how the miRNAs act to sustain and shape up the expression profiles of specific cell types; how the miRNAs integrate into the existing gene regulatory networks; and how the miRNAs influence the evolution of 3＇UTR of mammalian mRNAs.展开更多
Hot compression experiments were conducted on Ti 15 3 alloy specimens using Gleeble 1500 Thermal Simulator.These tests were focused to obtain the flow stress data under various conditions of strain,strain rate and tem...Hot compression experiments were conducted on Ti 15 3 alloy specimens using Gleeble 1500 Thermal Simulator.These tests were focused to obtain the flow stress data under various conditions of strain,strain rate and temperature. On the basis of these data, the predicting model for the nonlinear relation between flow stress and deformation strain,strain rate and temperature for Ti 15 3 alloy was developed with a back propagation artificial neural network method. Results show that the neural network can reproduce the flow stress in the sampled data and predict the nonsampled data well. Thus the neural network method has been verified to be used to tackle hot deformation problems of Ti 15 3 alloy. [展开更多
This paper rejuvenates the notion of conformance testing in order to assess the security of networks. It leverages the Testing and Test Control Notation Version 3 (TTCN-3) by applying it to a redefined notion of <i...This paper rejuvenates the notion of conformance testing in order to assess the security of networks. It leverages the Testing and Test Control Notation Version 3 (TTCN-3) by applying it to a redefined notion of <i>System under Test</i> (<i>SUT</i>). Instead of testing, as it is classically done, a software/firmware/ hardware element, an intangible object, namely the network, is tested in order to infer some of its security properties. After a brief introduction of TTCN-3 and Titan, its compilation and execution environment, a couple of use cases are provided to illustrate the feasibility of the approach. The pros and cons of using TTCN-3 to implement a scalable and flexible network testing environment are discussed.展开更多
The probability model is used to analyze the fault tolerance of mesh. To simplify its analysis, it is as-sumed that the failure probability of each node is independent. A 3-D mesh is partitioned into smaller submeshes...The probability model is used to analyze the fault tolerance of mesh. To simplify its analysis, it is as-sumed that the failure probability of each node is independent. A 3-D mesh is partitioned into smaller submeshes,and then the probability with which each submesh satisfies the defined condition is computed. If each submesh satis-fies the condition, then the whole mesh is connected. Consequently, the probability that a 3-D mesh is connected iscomputed assuming each node has a failure probability. Mathematical methods are used to derive a relationship be-tween network node failure probability and network connectivity probability. The calculated results show that the 3-D mesh networks can remain connected with very high probability in practice. It is formally proved that when thenetwork node failure probability is boutded by 0.45 %, the 3-D mesh networks of more than three hundred thousandnodes remain connected with probability larger than 99 %. The theoretical results show that the method is a power-ful technique to calculate the lower bound of the connectivity probability of mesh networks.展开更多
The 3-stage Clos network C（n, m, r） is considered as the most basic and popular multistage interconnection network which has been widely employed for data communications and parallel computing systems. Quite a lot o...The 3-stage Clos network C（n, m, r） is considered as the most basic and popular multistage interconnection network which has been widely employed for data communications and parallel computing systems. Quite a lot of efforts has been put on the research of the 3- stage Clos network. Unfortunately, very little is known for the multirate multicast Clos network which is the most complicated case. Firstly a sufficient condition for 1-rate multicast networks to be SNB is given, from which a result for 2-rate multicast networks to be WSNB can easily be gotten. Furthermore, by using a reservation-scheme routing, more specific result for 2-rate multicast networks to be WSNB can be obtained for the case of one of them exceeding 1/2.展开更多
As ubiquitous sensor networks (USN) technologies and its middleware are still at its early stages, the system of the USN relies on the middleware and applications. The past sensor networks are assumed to be designed f...As ubiquitous sensor networks (USN) technologies and its middleware are still at its early stages, the system of the USN relies on the middleware and applications. The past sensor networks are assumed to be designed for specific applications, having data communication protocols tightly coupled to applications. To avoid these problems, several kinds of USN middleware have been researched and developed. However, most middleware of USN are still restricted by its own infrastructure so far. This paper proposes appropriate 3 tier Smart Middleware System (3SMS) for USN.展开更多
文摘软件定义自组网(Software Defined Mobile Ad Hoc Network,SD-MANET)融合了软件定义网络(Software Defined Network,SDN)集中控制优势和移动自组网(Mobile Ad Hoc Network,MANET)的动态组网优势,但Mininet等现有仿真平台在动态拓扑与扩展性等方面存在显著局限,严重制约了其关键算法的研究。针对这一问题,提出基于网络模拟器-3(Network Simulator-3,NS-3)的仿真平台NS3-SDMANET,具体工作包括:基于NS-3框架实现了SD-MANET网络层关键特性的仿真;基于远程过程调用对平台功能进行封装,并提供可编程接口。战术网的测试案例表明:NS3-SDMANET在SD-MANET网络层关键特性仿真方面表现优异,能够有效支撑SD-MANET网络层算法的高效验证与性能评估,为相关研究提供了高扩展性的基础仿真环境。
基金supported by the National Basic Research Program of China (973 Program) (No. 2006CB701506 and 2007CB815705)the Chinese Academy of Sciences (No. KSCX1-YW-R-34)+1 种基金the National Natural Science Foundation of China (No. 30525028, 30630013 and 30871343)the Natural Science Foundation of Yunnan Province of China.
文摘MicroRNAs （miRNAs） are endogenous -22 nucleotide noncoding RNAs that regulate the expression of complementary messenger RNAs （mRNAs）. Thousands of miRNA genes have been found in diverse species, and many of them are highly conserved. With the miRNA roles identified in nearly all aspects of biological processes, evidence is mounting that miRNAs could represent a new layer of regulatory network, and their regulatory effect might be much more pervasive than previously suspected. Here we focus on the posttranscriptional level gene regulation of miRNAs in animals and review how the miRNAs act to sustain and shape up the expression profiles of specific cell types; how the miRNAs integrate into the existing gene regulatory networks; and how the miRNAs influence the evolution of 3＇UTR of mammalian mRNAs.
文摘Hot compression experiments were conducted on Ti 15 3 alloy specimens using Gleeble 1500 Thermal Simulator.These tests were focused to obtain the flow stress data under various conditions of strain,strain rate and temperature. On the basis of these data, the predicting model for the nonlinear relation between flow stress and deformation strain,strain rate and temperature for Ti 15 3 alloy was developed with a back propagation artificial neural network method. Results show that the neural network can reproduce the flow stress in the sampled data and predict the nonsampled data well. Thus the neural network method has been verified to be used to tackle hot deformation problems of Ti 15 3 alloy. [
文摘This paper rejuvenates the notion of conformance testing in order to assess the security of networks. It leverages the Testing and Test Control Notation Version 3 (TTCN-3) by applying it to a redefined notion of <i>System under Test</i> (<i>SUT</i>). Instead of testing, as it is classically done, a software/firmware/ hardware element, an intangible object, namely the network, is tested in order to infer some of its security properties. After a brief introduction of TTCN-3 and Titan, its compilation and execution environment, a couple of use cases are provided to illustrate the feasibility of the approach. The pros and cons of using TTCN-3 to implement a scalable and flexible network testing environment are discussed.
基金Project (69928201) supported by the National Science Fund for Distinguished Young Scholars+1 种基金project (90104028) by the National Natural Science Foundation of China Project by Changjiang Scholar Re-ward Project
文摘The probability model is used to analyze the fault tolerance of mesh. To simplify its analysis, it is as-sumed that the failure probability of each node is independent. A 3-D mesh is partitioned into smaller submeshes,and then the probability with which each submesh satisfies the defined condition is computed. If each submesh satis-fies the condition, then the whole mesh is connected. Consequently, the probability that a 3-D mesh is connected iscomputed assuming each node has a failure probability. Mathematical methods are used to derive a relationship be-tween network node failure probability and network connectivity probability. The calculated results show that the 3-D mesh networks can remain connected with very high probability in practice. It is formally proved that when thenetwork node failure probability is boutded by 0.45 %, the 3-D mesh networks of more than three hundred thousandnodes remain connected with probability larger than 99 %. The theoretical results show that the method is a power-ful technique to calculate the lower bound of the connectivity probability of mesh networks.
基金Supported by the National Natural Science Foundation of China(10371028)Specialized Research Fund for Outstanding Young Teachers in Shanghai Higher Education Institutions (RYQ307013)
文摘The 3-stage Clos network C（n, m, r） is considered as the most basic and popular multistage interconnection network which has been widely employed for data communications and parallel computing systems. Quite a lot of efforts has been put on the research of the 3- stage Clos network. Unfortunately, very little is known for the multirate multicast Clos network which is the most complicated case. Firstly a sufficient condition for 1-rate multicast networks to be SNB is given, from which a result for 2-rate multicast networks to be WSNB can easily be gotten. Furthermore, by using a reservation-scheme routing, more specific result for 2-rate multicast networks to be WSNB can be obtained for the case of one of them exceeding 1/2.
基金This work is supported by the Second Stage of Brain Korea 21 project in 2007 .
文摘As ubiquitous sensor networks (USN) technologies and its middleware are still at its early stages, the system of the USN relies on the middleware and applications. The past sensor networks are assumed to be designed for specific applications, having data communication protocols tightly coupled to applications. To avoid these problems, several kinds of USN middleware have been researched and developed. However, most middleware of USN are still restricted by its own infrastructure so far. This paper proposes appropriate 3 tier Smart Middleware System (3SMS) for USN.
