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121.
为均衡及降低无线传感器网络(WSN)的路由能耗并最终延长网络的寿命,提出一种具备网络编码感知且能耗敏感的WSN路由策略。该策略通过对WSN环境中存在的网络寿命限制、数据流限制、广播流量限制3个重要因素的分析,对能耗最优路由进行建模,最后归结为对最优化问题的求解获得最佳路径。仿真实验表明该路由策略能够较好地均衡节点的能耗,从整体上显著延长WSN的生存期。 相似文献
122.
An important step towards the successful integration of information and communication technology (ICT) in schools is to facilitate their capacity to develop a school‐based ICT policy resulting in an ICT policy plan. Such a plan can be defined as a school document containing strategic and operational elements concerning the integration of ICT in education. To write such a plan in an efficient way is challenging for schools. Therefore, an online tool [Planning for ICT in Schools (pICTos)] has been developed to guide schools in this process. A multiple case study research project was conducted with three Flemish primary schools to explore the process of developing a school‐based ICT policy plan and the supportive role of pICTos within this process. Data from multiple sources (i.e. interviews with school leaders and ICT coordinators, school policy documents analysis and a teacher questionnaire) were collected and analysed. The results indicate that schools shape their ICT policy based on specific school data collected and presented by the pICTos environment. School teams learned about the actual and future place of ICT in teaching and learning. Consequently, different policy decisions were made according to each school's vision on ‘good’ education and ICT integration. 相似文献
123.
In product design process, when dealing with technical problems or initiating a new design, R&D personnel would often turn to technical database to seek inspiration. The building of a database with such documents has not been systematically dealt with. In this paper, several issues on how to build up a product design database are investigated: input source, sampling scheme and quality control. A case study of building a database for robotic design is used to demonstrate the concept. It is an archive of more than 1500 relevant technical papers. A total of 16 graduates are employed as operators in the labeling process and subsequently the hypothesis tests are utilized to process the labeling results. To ensure this database quality, the labeling consistency of each operator and the understanding of each category are tested. With the use of statistical methods, this work proposes a feasible and practical way to create such a database for product design. 相似文献
124.
郭江平 《数字社区&智能家居》2010,(6):1309-1311
网络准入控制体系中,终端与策略服务器通过代理服务器连接。该文给出网络准入控制的实现流程,定义了代理服务器的功能。以Linux内核的网络模块为基础,提出一种两级过滤规则链的网络报文过滤方法,实现了准入控制代理的安全阻断功能。该文工作可作为网络准入控制代理服务器的实现参考与依据。 相似文献
125.
胡春 《数字社区&智能家居》2010,(5):1079-1080
网络已成为获取各种信息的重要手段,人们在享受着网络带来快乐的同时,也面临着越来越严重和复杂的网络安全威胁和难以规避的风险。该文从网络安全定义入手,全面分析了影响网络安全的因素,从而提出计算机网络安全防范相关措施,以确保网络安全有效运行。 相似文献
126.
127.
为解决传统遗传算法早熟收敛和收敛速度慢的问题,提出一种基于强化学习的多策略选择遗传算法MPSGA。通过使用不同的选择策略将整个种群划分为3个子种群并分别进化,能提高种群的多样性,有效避免遗传算法的早熟收敛问题。将种群的多样性和算法的运行机制相结合,根据种群多样性的变化运用强化学习算法动态地优化各子种群间的比例参数,从而将种群多样性保持在合适的范围,一定程度上解决了收敛速度和全局收敛性之间的矛盾。实验结果表明,该算法在收敛精度和搜索效率上都表现出较好的性能。 相似文献
128.
Pricing and inventory management in a system with multiple competing retailers under (r, Q) policies
We consider a multi-retailer system operated on an infinite horizon, in which each retailer faces stochastic demand following a Poisson process and adopts a continuous-review (r, Q) policy for replenishing inventory to satisfy customer demand. The system involves decisions of pricing and inventory management with the goal of maximizing profit, which equals the sales revenue minus the purchase and inventory costs. Taking Cournot competition into account, models are formulated to optimize simultaneously the expected sales volumes and (r, Q) policies of all retailers. An efficient approach is proposed to calculate the approximate inventory cost. Based on this approach, solution methods for centralized and decentralized scenarios are developed. A great number of numerical computations are provided to evaluate the efficiency of the solution methods, and their performance in the two scenarios. Moreover, system performance under sequential decisions (first pricing and then inventory management) is also investigated. 相似文献
129.
研究单站点传送带给料生产加工站(conveyor-serviced production station,CSPS)系统的前视(look-ahead)距离最优控制问题,以提高系统的工作效率.论文运用半Markov决策过程对CSPS优化控制问题进行建模.考虑传统Q学习难以直接处理CSPS系统前视距离为连续变量的优化控制问题,将小脑模型关节控制器网络的Q值函数逼近与在线学习技术相结合,给出了在线Q学习及模型无关的在线策略迭代算法.仿真结果表明,文中算法提高了学习速度和优化精度. 相似文献
130.
Automated trust negotiation (ATN) is an approach establishing mutual trust between strangers wishing to share resources or conduct business by gradually requesting and disclosing digitally signed credentials. The digital credentials themselves are usually sensitive, so they have corresponding access control policies to control their disclosure. Therefore, an ATN strategy must be adopted to determine the search for a successful negotiation based on the access control policies. Previously proposed negotiation strategies are either not complete, disclosing irrelevant credentials, or not efficient enough. In this paper, we propose a novel ATN strategy, that is, Deterministic Finite Automaton Negotiation Strategy (DFANS). DFANS is complete and ensures that no irrelevant credentials are disclosed during the negotiation. Furthermore, DFANS is highly efficient. In the worst case, its communication complexity is O(n), where n is the total number of credentials requested, and its computational complexity is O(m) when not involving the cyclic dependencies, where m is the total size of the both sides' policies looked up during the negotiation. When cyclic dependencies exist, a reasonable additional cost of running OSBE protocol that is a provably secure and quite efficient scheme will be added to the computational cost of DFANS to guarantee the negotiation success whenever possible. 相似文献