Decentralized MDPs with sparse interactions

Creating coordinated multiagent policies in environments with uncertainty is a challenging problem, which can be greatly simplified if the coordination needs are known to be limited to specific parts of the state space. In this work, we explore how such local interactions can simplify coordination in multiagent systems. We focus on problems in which the interaction between the agents is sparse and contribute a new decision-theoretic model for decentralized sparse-interaction multiagent systems, Dec-SIMDPs, that explicitly distinguishes the situations in which the agents in the team must coordinate from those in which they can act independently. We relate our new model to other existing models such as MMDPs and Dec-MDPs. We then propose a solution method that takes advantage of the particular structure of Dec-SIMDPs and provide theoretical error bounds on the quality of the obtained solution. Finally, we show a reinforcement learning algorithm in which independent agents learn both individual policies and when and how to coordinate. We illustrate the application of the algorithms throughout the paper in several multiagent navigation scenarios.     

事务控制的面向服务系统的动态更新协调

就面向服务的分布式系统中多服务动态更新的协调问题,提出基于事务控制的更新协调策略,包括安全更新时机的选择策略、使用2PC(two-phase-commit)协调多服务更新的控制策略.根据更新实施的各步操作时间开销,提出分别采用更新短事务控制基本更新操作(包括创建服务实例、顺序实施运行时状态转换、重定向服务请求和新服务的...     

基于CVaR的闭环供应链优化与协调决策研究

利用条件风险值理论研究具有风险规避特性的闭环供应链的优化与协调问题.首先,建立了随机市场需求下由单个风险规避零售商与单个风险规避制造商组成的两阶闭环供应链的条件风险值模型,以及基于条件风险值的收益共享费用共担契约下的最优订购量和最优批发价格决策模型;然后在对模型进行分析的基础上,揭示了制造商和零售商的风险规避水平对最优订购量、批发价格、条件风险值及闭环供应链协调的影响;最后通过一个算例验证了所得的结论.     

基于成本共担策略的服务供应链协调研究

研究由服务提供商和支持服务供应商组成的两级服务供应链.其中市场需求与支持服务供应商的努力水平相关,服务容量与服务提供商的努力水平相关.建立了基于成本共担策略的服务供应链模型,分析得到了供应链成员同时决策与序贯决策情况下供应链的Nash均衡解.研究表明,成本共担策略能提高供应链的总利润,实现供应链协调.通过大量算例分析了最优协调参数解与供应链中重要参数的关系,同时指出了供应链协调的效果.     

多指机器人手协调控制研究进展

本文综述了关于多指机器人手协调控制方面的研究进展情况．文章分为三个部分．第 一部分介绍了多指机器人手各方面的研究现状;第二部分讨论协调控制,主要是力分配算法 方面的研究成果;第三部分探讨了自主抓取的实现方法,并提出对未来研究的设想．     

Surface Reconstruction based on Lower Dimensional Localized Delaunay Triangulation

We present a fast, memory efficient algorithm that generates a manifold triangular mesh S passing through a set of unorganized points P R ³. Nothing is assumed about the geometry, topology or presence of boundaries in the data set except that P is sampled from a real manifold surface. The speed of our algorithm is derived from a projection-based approach we use to determine the incident faces on a point. We define our sampling criteria to sample the surface and guarantee a topologically correct mesh after surface reconstruction for such a sampled surface. We also present a new algorithm to find the normal at a vertex, when the surface is sampled according our given criteria. We also present results of our surface reconstruction using our algorithm on unorganized point clouds of various models.     

From insect to Internet: Situated control for networked robot teams

Ant-like systems take advantage of agents' situatedness to reduce or eliminate the need for centralized control or global knowledge. This reduces the need for complexity of individuals and leads to robust, scalable systems. Such insect-inspired situated approaches have proven effective both for task performance and task allocation. The desire for general, principled techniques for situated interaction has led us to study the exploitation of abstract situatedness – situatedness in non-physical environments. The port-arbitrated behavior-based control approach provides a well-structured abstract behavior space in which agents can participate in situated interaction. We focus on the problem of role assumption, distributed task allocation in which each agent selects its own task-performing role. This paper details our general, principled Broadcast of Local Eligibility (BLE) technique for role-assumption in such behavior-space-situated systems, and provides experimental results from the CMOMMT target-tracking task. This revised version was published online in August 2006 with corrections to the Cover Date.     

Structured Reactive Controllers

Service robots, such as autonomous office couriers or robot tourguides, must be both reliable and efficient. This requires them to flexibly interleave their tasks, exploit opportunities, quickly plan their course of action, and, if necessary, revise their intended activities. In this paper, we show how structured reactive controllers (SRCs) satisfy these requirements. The novel feature of SRCs is that they employ and reason about plans that specify and synchronize concurrent percept-driven behavior. Powerful control abstractions enable SRCs to integrate physical action, perception, planning, and communication in a uniform framework and to apply fast but imperfect computational methods without sacrificing reliability and flexibility. Concurrent plans are represented in a transparent and modular form so that automatic planning processes can reason about the plans and revise them. We present experiments in which SRCs are used to control two autonomous mobile robots. In one of them an SRC controlled the course of action of a museum tourguide robot that has operated for thirteen days, more than ninetyfour hours, completed 620 tours, and presented 2668 exhibits.     

Time-bound negotiation framework for electronic commerce agents

For efficient and informative coordination of agents especially in electronic commerce environment, a time-bound agent negotiation framework is proposed utilizing a time-based commitment scheme. By attaching commitment duration to agent messages, the traditional contract net protocol is extended to a time-bound negotiation framework (TBNF). The proposed negotiation framework has a new message type which allows for parties to agree upon the extension of a commitment duration, and a novel commitment concept in the form of negative commitment. The semantics of the messages with the commitment duration are interpreted, and then the three typical negotiation protocols are formally defined and compared — nothing-guaranteed protocol, acceptance-guaranteed protocol, and finite-time guarantee protocol — which can be incorporated into TBNF. The TBNF should provide a background for efficient and effective electronic commerce negotiation while accommodating each agent's adaptive negotiation strategy.