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81.
This paper presents a cooperative decentralized path-planning algorithm for a group of autonomous agents that provides guaranteed collision-free trajectories in real-time. The algorithm is robust with respect to arbitrary delays in the wireless traffic, possible sources being transmission time and error correction. Agents move on reserved areas which are guaranteed not to intersect, therefore ensuring safety. A handshaking procedure guarantees recent information states for the agents. Conflicts between agents are resolved by a cost-based negotiation process. The basic algorithm is augmented by the introduction of waypoints, which increase performance at the cost of additional wireless traffic. An implementation of the algorithm is tested in simulation and successfully applied to a real system of autonomous robots. The results are presented and discussed. 相似文献
82.
Traditionally, two alternative design approaches have been available to engineers: top-down and bottom-up. In the top-down
approach, the design process starts with specifying the global system state and assuming that each component has global knowledge
of the system, as in a centralized approach. The solution is then decentralized by replacing global knowledge with communication.
In the bottom-up approach, on the other hand, the design starts with specifying requirements and capabilities of individual
components, and the global behavior is said to emerge out of interactions among constituent components and between components
and the environment. In this paper we present a comparative study of both approaches with particular emphasis on applications
to multi-agent system engineering and robotics. We outline the generic characteristics of both approaches from the MAS perspective,
and identify three elements that we believe should serve as criteria for how and when to apply either of the approaches. We
demonstrate our analysis on a specific example of load balancing problem in robotics. We also show that under certain assumptions
on the communication and the external environment, both bottom-up and top-down methodologies produce very similar solutions.
相似文献
Valentino CrespiEmail: |
83.
A dynamic workflow framework for mass customization using web service and autonomous agent techniques 总被引:3,自引:1,他引:2
Daniel J. Karpowitz Jordan J. Cox Jeffrey C. Humpherys Sean C. Warnick 《Journal of Intelligent Manufacturing》2008,19(5):537-552
Custom software development and maintenance is one of the key expenses associated with developing automated systems for mass
customization. This paper presents a method for reducing the risk associated with this expense by developing a flexible environment
for determining and executing dynamic workflow paths. Strategies for developing an autonomous agent-based framework and for
identifying and creating web services for specific process tasks are presented. The proposed methods are outlined in two different
case studies to illustrate the approach for both a generic process with complex workflow paths and a more specific sequential
engineering process. 相似文献
84.
This paper investigates the controllability of multi-agent systems based on agreement protocols. First, for a group of single-integrator
agents, the controllability is studied in a unified framework for both networks with leader-following structure and networks
with undirected graph. Some new necessary/sufficient conditions for the controllability of networks of single-integrator agents
are established. Second, we prove that, under the same topology and same prescribed leaders, a network of high-order dynamic
agents is completely controllable if and only if so is a network of single-integrator agents. Third, how the selection of
leaders and the coupling weights of graphs affect the controllability is analyzed. Finally, some numerical simulations are
presented to demonstrate the effectiveness of the theoretical results. 相似文献
85.
An important problem in agent verification is a lack of proper understanding of the relation between agent programs on the
one hand and agent logics on the other. Understanding this relation would help to establish that an agent programming language
is both conceptually well-founded and well-behaved, as well as yield a way to reason about agent programs by means of agent
logics. As a step toward bridging this gap, we study several issues that need to be resolved in order to establish a precise
mathematical relation between a modal agent logic and an agent programming language specified by means of an operational semantics. In this paper, we present an agent programming theory that provides both an agent programming language as well as a corresponding agent verification logic to verify agent programs.
The theory is developed in stages to show, first, how a modal semantics can be grounded in a state-based semantics, and, second, how denotational semantics can be used to define the mathematical relation connecting the logic and agent programming language. Additionally, it is
shown how to integrate declarative goals and add precompiled plans to the programming theory. In particular, we discuss the
use of the concept of higher-order goals in our theory. Other issues such as a complete axiomatization and the complexity
of decision procedures for the verification logic are not the focus of this paper and remain for future investigation.
Part of this research was carried out while the first author was affiliated with the Nijmegen Institute for Cognition and
Information, Radboud University Nijmegen. 相似文献
86.
Maze problems represent a simplified virtual model of the real environment and can be used for developing core algorithms
of many real-world application related to the problem of navigation. Learning Classifier Systems (LCS) are the most widely
used class of algorithms for reinforcement learning in mazes. However, LCSs best achievements in maze problems are still mostly
bounded to non-aliasing environments, while LCS complexity seems to obstruct a proper analysis of the reasons for failure.
Moreover, there is a lack of knowledge of what makes a maze problem hard to solve by a learning agent. To overcome this restriction
we try to improve our understanding of the nature and structure of maze environments. In this paper we describe a new LCS
agent that has a simpler and more transparent performance mechanism. We use the structure of a predictive LCS model, strip
out the evolutionary mechanism, simplify the reinforcement learning procedure and equip the agent with the ability to Associative
Perception, adopted from psychology. We then assess the new LCS with Associative Perception on an extensive set of mazes and
analyse the results to discover which features of the environments play the most significant role in the learning process.
We identify a particularly hard feature for learning in mazes, aliasing clones, which arise when groups of aliasing cells
occur in similar patterns in different parts of the maze. We discuss the impact of aliasing clones and other types of aliasing
on learning algorithms. 相似文献
87.
IHAB M. Elfituri 《计算机辅助绘图.设计与制造(英文版)》2008,(2)
Despite its name, e-commerce is not fully automated. Typically, online transactions require a significant level of human intervention. Customers undertake the search for products, services, potential vendors and business partners. They evaluate alternatives, decide what goods to buy and when, from which vendor, and how much they are willing to pay for. They engage in potential negotiations, carry out the transactions and so on. As those markets become mature, new products and services, as well as new practi... 相似文献
88.
Synthesis of Branched DNA Scaffolded Super‐Nanoclusters with Enhanced Antibacterial Performance
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Lu Yang Chi Yao Feng Li Yuhang Dong Zhikun Zhang Dayong Yang 《Small (Weinheim an der Bergstrasse, Germany)》2018,14(16)
Metal nanoclusters (NCs) possess unique optical properties, and exhibit a wide variety of potential applications. DNA with robust molecular programmability is demonstrated as an ideal scaffold to regulate the formation of NCs, offering a rational approach to precisely tune the spatial structures of NCs. Herein, the first use of branched DNA as scaffold to regulate the formation of silver nanoclusters (super‐AgNC) is reported, in which the spatial structures are precisely designed and constructed. Super‐AgNC with tunable shapes and arm‐lengths including Y‐, X‐, and (Y–X)‐ shaped super‐AgNC is achieved. The molecular structures and optical properties of super‐AgNCs are systemically studied. As a proof of application, remarkably, super‐AgNCs exhibit superior antibacterial performance. In addition, super‐AgNCs show excellent biocompatibility with three types of tissue cells including 293T (human embryonic kidney cells), SMCs (vascular smooth muscle cells), and GLC‐82 (lung adenocarcinoma cells). These performances enable the super‐AgNCs adaptable in a variety of applications such as biosensing, bioimaging, and antibacterial agents. 相似文献
89.
Orphan detection in distributed systems is a well-researched field for which many solutions exist. These solutions exploit well defined parent-child relationships given in distributed systems. But they are not applicable in mobile agent systems, since no similar natural relationship between agents exist. Thus new protocols have to be developed. In this paper one such protocol for controlling mobile mobile agents and for orphan detection is presented. The shadow approach presented in this paper uses the idea of a placeholder (shadow) which is assigned by the agent system to each new agent. This defines an artificial relationship between agents and shadow. The shadow records the location of all dependent agents. Removing the root shadow implies that all dependent agents are declared orphan and are eventually be terminated. We introduce agent proxies that create a path from shadow to every agent. In an extension of the basic protocol we additionally allow the shadow to be mobile.The shadow approach can be used for termination of groups of agents even if the exact location of each single agent is not known. 相似文献
90.