9544952
An Approach to Building Mobile Intelligent Agents Based on Anytime Migration
In this paper, we present an implementation of a Java-based framework for building mobile agents : MiLog (Mobile intelligent agents using Logic programming). MiLog provides logic programming and Java programming for developing intelligent agents since it helps users to effectively construct intelligent mechanisms. We address how to realize an anytime migration mechanism, a HTTP(Hyper Text Transfer Protocol)-based communication mechanism among agents, and web service/access mechanism. Anytime migration enables agents to reactively and autonomously migrate from one computer to another. We present practical applications that have been built on MiLog framework. These applications demonstrate that MiLog is an effective tool for developing practical applications based on mobile intelligent agents.
1779412
Designing an auction protocol under asymmetric information on nature's selection
Internet auctions are becoming an especially popular part of Electronic Commerce and auction protocols have been studied very widely in the field of multi-agent systems and AI. However, correctly judging the quality of auctioned goods is often difficult for non-experts (amateurs), in particular, on the Internet auctions. In this paper, we formalize such a situation so that Nature selects the quality of the auctioned good. Experts can observe Nature's selection (i.e., the quality of the good) correctly, while amateurs including the auctioneer cannot. In other words, the information on Nature's selection is asymmetric between experts and amateurs. In this situation, it is difficult to attain an efficient allocation, since experts have a clear advantage over amateurs and they would not reveal their valuable information without some reward. Thus, in this paper, we develop a new auction protocol in which truth-telling is a dominant strategy for each expert. This can be done by putting these experts in a situation similar to Prisoner's Dilemma. If they cooperate and tell lies, they can exclude amateurs, but betraying is a dominant strategy. By making experts to elicit their information on the quality of the good, the protocol can achieve a socially desirable, i.e., Pareto efficient allocation if certain assumptions are satisfied.
5841312
Coalition Formation among Agents in Complex Problems Based on a Combinatorial Auction Perspective
AbstrAct This chapter focuses on a scheduling problem that considers various constraints as a complex real-world problem. Constraints on scheduling can be expressed as combinations of items (time slots) in a combinatorial auction. Agents bid for necessary combinations of time slots to satisfy users' preferences. We formalize a combinatorial auction for scheduling as an MIP (mixed integer programming) problem, which integrates the constraints on items and bids to express complex problems. This integration solves the trade-off between the computation time to find the solution and the expressiveness to represent a scheduling problem. This chapter presents a new formalization of a combinatorial auction with constraints. We have experimentally confirmed that our method can obtain a socially preferable schedule in practical time.
13087182
A Logic-based Framework for Mobile Intelligent Information Agents
Information agents are computational software systems that provides transparent access to many different information sources in the Internet, and to be able to retrieve, analyze, manipulate, and integrate heterogeneous data and information on demand. Mobile agents are an effective choice for many applications to improve latency and bandwidth of client-server applications and to reduce vulnerability to network disconnection. In this paper, we propose MiLog, a logic-based mobile agent framework for constructing intelligent information agents. In the framework, inference and planning process of an agent is written in a compact logic program. A new generation logic program execution engine provides strong migration capability with reasonable execution speed. The framework has been used to develop a web-based decision support system ’BiddingBot’.
39083447
A new distributed approach to solve meeting scheduling problems
Meeting Scheduling (MS) is an important real world-problem that is defined by the process of scheduling meetings while taking into account several constraints related to the availability and preferences of the users. The main contribution of this paper is to propose a new approach based on the DRAC model (distributed reinforcement of arc consistency) to solve the MS problem. A simplified version of this approach was implemented and compared with an approach of the state of the art. The experimental results show that our approach is scalable.
8383423
A Support Method for Qualitative Simulation-Based Learning System
In this paper, we mainly present a support method of our proposed e-learning system. We employ qualitative simulations because this lets the learners understand the conceptual principles in economic dynamics. First, we define some qualitative values employed on simulation graph model that consists of nodes and arcs. Then, we show the support method using our learning system based on qualitative simulation.
11122815
Algorithms for the Multicolorings of Partial k-Trees
Let each vertex v of a graph G have a positive integer weight ?(v). Then a multicoloring of G is to assign each vertex v a set of ?(v) colors so that any pair of adjacent vertices receive disjoint sets of colors. A partial k-tree is a graph with tree-width bounded by a fixed constant k. This paper presents an algorithm which finds a multicoloring of any given partial k-tree G with the minimum number of colors. The computation time of the algorithm is bounded by a polynomial in the number of vertices and the maximum weight of vertices in G.
751173
Approximability of Partitioning Graphs with Supply and Demand
Suppose that each vertex of a graph G is either a supply vertex or a demand vertex and is assigned a positive real number, called the supply or the demand. Each demand vertex can receive “power” from at most one supply vertex through edges in G. One thus wishes to partition G into connected components so that each component C either has no supply vertex or has exactly one supply vertex whose supply is at least the sum of demands in C, and wishes to maximize the fulfillment, that is, the sum of demands in all components with supply vertices. This maximization problem is known to be NP-hard even for trees having exactly one supply vertex and strongly NP-hard for general graphs. In this paper, we focus on the approximability of the problem. We first show that the problem is MAXSNP-hard and hence there is no polynomial-time approximation scheme (PTAS) for general graphs unless P=NP. We then present a fully polynomial-time approximation scheme (FPTAS) for series-parallel graphs having exactly one supply vertex. The FPTAS can be easily extended for partial k-trees, that is, graphs with bounded treewidth.
40835687
Partitioning trees of supply and demand
Assume that a tree T has a number ns of "supply vertices" and all the other vertices are "demand vertices." Each supply vertex is assigned a positive number called a supply, while each demand vertex is assigned a positive number called a demand. One wishes to partition T into exactly ns subtrees by deleting edges from T so that each subtree contains exactly one supply vertex whose supply is no less than the sum of demands of all demand vertices in the subtree. The "partition problem" is a decision problem to ask whether T has such a partition. The "maximum partition problem" is an optimization version of the partition problem. In this paper, we give three algorithms for the problems. The first is a linear-time algorithm for the partition problem. The second is a pseudo-polynomial-time algorithm for the maximum partition problem. The third is a fully polynomial-time approximation scheme (FPTAS) for the maximum partition problem.
40274616
On the spectra of certain distance-regular graphs
Let r be an undirected graph whose vertex-set V(F) is the set (ZJ~ , u2 ,..., v,>. The adjacency matrix of I’ is the n x n matrix A = A(r), over the complex number field, whose entries aij are given by a,j = 1 if vi and vi are adjacent, = 0 otherwise. DEFINITION 1. The spectrum of r is the set of distinct eigenvalues 4l , 4 ,**-> Od of A(F), together with their multiplicities, written m(&), m(4),..., m(0,). Since r is undirected, A is symmetric, and so the Bi are all real numbers. We arrange the Bi in increasing order, namely, 0, < O1 < *.. < e dMany studies have been done on the spectra of graphs by many mathematicians. Some of them may be found, for instance, in Biggs [2].
32325022
Algorithms for Finding Distance-Edge-Colorings of Graphs
For a bounded integer l, we wish to color all edges of a graph G so that any two edges within distance l have different colors. Such a coloring is called a distance-edge-coloring or an l-edge-coloring of G. The distance-edge-coloring problem is to compute the minimum number of colors required for a distance-edge-coloring of a given graph G. A partial k-tree is a graph with tree-width bounded by a fixed constant k. We first present a polynomial-time exact algorithm to solve the problem for partial k-trees, and then give a polynomial-time 2-approximation algorithm for planar graphs.