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为提高对未知目标的拦截能力,基于博弈理论,研究了一种由水下拦截器和我方舰艇协同防卫来袭目标的微分制导策略。该策略在三方对策关系基础上,结合视线指令构造协同约束,建立三方自导约束模型,以终端脱靶量和最小能量为性能指标进行协同对策制导律设计。利用伴随原理解决终端问题方法导出具有反馈控制的“零效脱靶量”,并以滚动时域法对制导参数进行实时预测。通过对可捕获条件下不同制导方式来袭目标的拦截仿真表明:在相同条件下,该制导策略弹道性能良好,不受目标机动形式的限制,具有较强的鲁棒性和稳定性。 相似文献
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The fractal manufacturing system (FrMS) is based on the concept of autonomously cooperating agents referred to as fractals. A fractal is a set of self-similar agents whose goal can be achieved through cooperation, coordination, and negotiation among the agents for themselves. A fractal has fractal-specific characteristics (e.g. self-similarity, self-organization, self-optimization, goal-orientation, and dynamics), and it also has the characteristics of an agent (e.g. autonomy, mobility, intelligence, cooperation, and adaptability) at the same time. In the FrMS, a goal can be regarded as the status which the system aspires to be in. The goal-formation process (GFP) in the FrMS is a process of generating goals and modifying them by coordination between agents. In the GFP, conflicts may occur between goals, which can drive a system to become inefficient. In this paper, a conflict resolution mechanism via agent-based negotiation is proposed for facilitating the GFP. The scheme deals with non-fixed goals. The mobile agent-based negotiation process (MANPro), in which a mobile agent is used for information-exchanging and problem-solving, is used for negotiations in this scheme. The proposed mechanism is illustrated with a goal formation scenario in an exemplary FrMS. 相似文献
125.
Pedestrian–vehicle conflicts are considered as a common safety problem at signalized intersections. The threat to pedestrian safety is mainly related to the interaction with turning vehicles, especially left-turners (left-hand traffic system). This study aims to analyze the lag/gap acceptance behavior of left-turners considering pedestrian movement at signalized crosswalks. Furthermore, the severity of pedestrian–vehicle conflicts is addressed by analyzing vehicle speeds at the conflict points. User behavior at several signalized intersections in Japan is observed by using video cameras. It is assumed that pedestrian movements have their origin at either the near-side (the side of the exiting vehicular traffic) or far-side of the crosswalk. Accepted/rejected lags and gaps are extracted, classified depending on the direction of pedestrian movement, and modeled by using Cumulative Weibull distribution function. The results show that drivers tend to accept shorter lags/gaps between near-side pedestrians compared to far side pedestrians. Furthermore, drivers tend to accept short lags while being conservative about short gaps. Simultaneously vehicles clear the conflict area with significantly higher speeds when accepting lags with single pedestrians. This indicates that the conflicts that occur at low pedestrian demand levels are more severe compared to those at high demand levels. 相似文献
126.
While most scientific journals have well defined ethics requirements for authors, very few journals explicitly specify the
ethics standards that govern the actions of editors, editorial board members, and reviewers. We believe it is time to create
a standardized policy for all medical and scientific journals that guides the ethical conduct of all stakeholders in the peer
review process. 相似文献
127.
在LTE(长期演进)上行随机接入中,接收端对前导的检测是一个很重要的步骤。由于前导序列较长,传统的接收端算法运算量较大。为了减小接收端算法的运算量,引入降采样,对传统的接收端算法进行改进。改进后的接收端算法运算量大大减少。以格式0为例,在一个计算周期内,改进后的算法运算量是改进前运算量的1/120。MTLAB仿真结果表明,改进前后的接收端算法在检测性能上差别较小。在不同的信道环境下,经过改进后的算法仍然具有较好的检测性能。 相似文献
128.
Hilary Schaffer Boudet Dilanka Chinthana Jayasundera Jennifer Davis 《Canadian Metallurgical Quarterly》2011,137(7):498-511
Despite the considerable scholarship focused on infrastructure investment in the developing world and the substantial sums of money spent each year on developing-country infrastructure, little attention has been given to understanding the drivers of conflict that shape the trajectory and cost structures of these massive investments. The manifestation of conflict among stakeholders in infrastructure projects ranges from the renegotiation of contract terms by project partners to popular protests among consumers of privatized services. The principal objective of this research is to identify combinations of country, project, and stakeholder factors that are associated with the emergence of legal and political conflict within natural gas and oil pipeline projects and water supply concessions and leases. The analysis includes data from 26 infrastructure projects spanning 31 countries and uses an analytical approach derived from Boolean algebra. Country-level characteristics, such as extent of democracy and rate of international NGO membership, are found to be important elements in the recipes for conflict among water supply projects but not for pipeline projects. Local impacts such as service price increases (water supply) and limited provision of oil and gas to the project host country (pipelines) are also important drivers of conflict for both subsectors. The involvement of one or more international financial institutions is also associated with the emergence of conflict in projects. Contrary to expectations, public consultation is associated with conflict in both subsectors. Overall, the study findings suggest that several factors associated with conflict in infrastructure projects can be minimized with careful project design. 相似文献
129.
Marsee Monica A.; Barry Christopher T.; Childs Kristina K.; Frick Paul J.; Kimonis Eva R.; Mu?oz Luna C.; Aucoin Katherine J.; Fassnacht Gregory M.; Kunimatsu Melissa M.; Lau Katherine S. L. 《Canadian Metallurgical Quarterly》2011,23(3):792
This study examined the structure of a self-report measure of the forms and functions of aggression in 855 adolescents (582 boys, 266 girls) aged 12 to 19 years recruited from high school, detained, and residential settings. The Peer Conflict Scale (PCS) is a 40-item measure that was developed to improve upon existing measures and provide an efficient, reliable, and valid assessment of four dimensions of aggression (i.e., reactive overt, reactive relational, proactive overt, and proactive relational) in youths. Confirmatory factor analyses showed that a 4-factor model represented a satisfactory solution for the data. The factor structure fit well for both boys and girls and across high school, detained, and residential samples. Internal consistency estimates were good for the 4 factors, and they showed expected associations with externalizing variables (i.e., arrest history, callous-unemotional traits, and delinquency). Reactive and proactive subtypes showed unique associations consistent with previous literature. Implications for the use of the PCS to assess aggression and inform intervention decisions in diverse samples of youths are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
130.