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151.
The nature of adhoc networks makes them vulnerable to security attacks. Many security technologies such as intrusion prevention and intrusion detection are passive in response to intrusions in that their countermeasures are only to protect the networks, and there is no automated network-wide counteraction against detected intrusions. the architecture of cooperation intrusion response based multi-agent is propose. The architecture is composed of mobile agents. Monitor agent resides on every node and monitors its neighbor nodes. Decision agent collects information from monitor nodes and detects an intrusion by security policies. When an intruder is found in the architecture, the block agents will get to the neighbor nodes of the intruder and form the mobile firewall to isolate the intruder. In the end, we evaluate it by simulation.  相似文献   
152.
闫丽梅  张江  陈娟 《系统仿真学报》2007,19(18):4104-4106,4110
系统的脆性分析的关键是要建立脆性模型。图论针对网络系统可以描述出系统脆性传播的方向和权重。提出了基于图论理论的系统脆性模型建立的方法和步骤。针对7节点电力系统进行了理论的建模和分析,求出了分层的电力系统脆性模型和脆性源。证明了此方法对于网络系统分析的有效性。  相似文献   
153.
Most cipher systems designed thus far are binary-valued or integer-valued cipher systems. Their security relies on the assumption that one-way functions exist. Though the existence of one-way functions has not been proved yet, most cryptographic researchers believe that one-way functions exist. In addition, many candidates for one-way functions have been proposed. Therefore, the key step for developing real-valued cipher systems is to define real one-way functions and to propose candidates for them. In this paper, based on computational complexity theory over the real field, we give two definitions of real one-way functions; one is for digital one-way functions and the other is for general one-way functions. Candidates for these two classes of one-way functions are also proposed. Moreover, we present two examples to demonstrate that the candidates for both digital one-way functions and general one-way functions can be applied to construct secure real-valued cipher systems.  相似文献   
154.
城市快速轨道交通接运公交路线网规划   总被引:13,自引:0,他引:13  
合理的接运公交线网规划是城市快速轨道交通系统充分发挥作用的保证,其关键环节是接运站点的选取和接运路线的优化。接运站点以它可能为轨道路线接运的最大客运周转量来选取;接运路线以接运效率最大为目标搜索优化  相似文献   
155.
邵锐  蒋馥 《系统工程学报》1998,13(1):102-107
用金融期权的分析方法研究了非完全竞争市场条件下风险、企业的等效边际成本和投资规模之间的关系,并讨论了需求弹性和企业商品的市场占有率的影响.研究表明风险促使企业降低等效边际成本,导致边际成本随资本量递减企业增加投资,递增企业减少投资.需求弹性和企业商品的市场占有率对等效边际成本和投资规模也有明显的影响.  相似文献   
156.
针对武器装备体系组合规划问题中存在多类相互冲突的高维多目标问题(目标数 ≥ 5),提出了一种三阶段的集成优化决策方法. 首先运用目的规划技术将高维多目标问题转换为一般多目标优化模型(目标数 ≤ 3); 然后提出一种多目标差分进化算法,用于搜索属于决策者关心区间的非劣解集; 最后提出基于预测优化的理想点算法,可生成精确满足决策者偏好的最佳折衷解. 通过某侦察装备体系组合规划示例,证明了各算法模块的优势和该方法的整体有效性,可为武器装备发展和顶层规划提供决策支持.  相似文献   
157.
This paper investigates the termination problems of multi-path polynomial programs (MPPs) with equational loop guards. To establish sufficient conditions for termination and nontermination simultaneously, the authors propose the notion of strong/weak non-termination which under/over- approximates non-termination. Based on polynomial ideal theory, the authors show that the set of all strong non-terminating inputs (SNTI) and weak non-terminating inputs (WNTI) both correspond to tile real varieties of certain polynomial ideals. Furthermore, the authors prove that the variety of SNTI is computable, and under some sufficient conditions the variety of WNTI is also computable. Then by checking the computed SNTI and WNTI varieties in parallel, termination properties of a consid- ered MPP can be asserted. As a consequence, the authors establish a new framework for termination analysis of MPPs.  相似文献   
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160.
Programmable and autonomous computing machine made of biomolecules.   总被引:42,自引:0,他引:42  
Y Benenson  T Paz-Elizur  R Adar  E Keinan  Z Livneh  E Shapiro 《Nature》2001,414(6862):430-434
Devices that convert information from one form into another according to a definite procedure are known as automata. One such hypothetical device is the universal Turing machine, which stimulated work leading to the development of modern computers. The Turing machine and its special cases, including finite automata, operate by scanning a data tape, whose striking analogy to information-encoding biopolymers inspired several designs for molecular DNA computers. Laboratory-scale computing using DNA and human-assisted protocols has been demonstrated, but the realization of computing devices operating autonomously on the molecular scale remains rare. Here we describe a programmable finite automaton comprising DNA and DNA-manipulating enzymes that solves computational problems autonomously. The automaton's hardware consists of a restriction nuclease and ligase, the software and input are encoded by double-stranded DNA, and programming amounts to choosing appropriate software molecules. Upon mixing solutions containing these components, the automaton processes the input molecule via a cascade of restriction, hybridization and ligation cycles, producing a detectable output molecule that encodes the automaton's final state, and thus the computational result. In our implementation 1012 automata sharing the same software run independently and in parallel on inputs (which could, in principle, be distinct) in 120 microl solution at room temperature at a combined rate of 109 transitions per second with a transition fidelity greater than 99.8%, consuming less than 10-10 W.  相似文献   
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