Smart cluster bombs - control of multi-agent systems for military applications

This paper introduces an aggregation algorithm for airborne swarming guided weapon systems, which can aggregate munitions into a given shape while reaching the surface. The algorithm uses an artificial force based controller to navigate the members of the swarm into the desired geographical position and evenly distribute them inside the shape. Inter-member repulsion forces are used to avoid collisions among members, which is crucial for a weapon deployment system. Moreover, a lower bound for the release height was obtained which guarantee convergence of the complete weapon system into the target area. The proposed swarming guided weapon system was tested using computer simulations.

Secure mobile agent-based e-negotiation for on-line trading

Electronic negotiation (e-negotiation) is a major activity in e-Commerce applications. Agent-based e-negotiation has recently received increasing attention. However, agent-based electronic negotiation suffers from a number of security attacks. In this paper, we present a mobile agent-based e-commerce framework. We also propose a security protocol that protects the information exchanged between the mobile agents during e- negotiations. We reason the correctness of the proposed security protocol in the presence of various security threats. The reasoning shows that the protocol maintains privacy, non- repudiation, authenticity, anonymity, and strong integrity of exchanged information.

Information sharing between heterogeneous uncertain reasoning models in a multi-agent environment : a case study

The issue of information sharing and exchanging is one of the most important issues in the areas of artificial intelligence and knowledge-based systems (KBSs), or even in the broader areas of computer and information technology. This paper deals with a special case of this issue by carrying out a case study of information sharing between two well-known heterogeneous uncertain reasoning models: the certainty factor model and the subjective Bayesian method. More precisely, this paper discovers a family of exactly isomorphic transformations between these two uncertain reasoning models. More interestingly, among isomorphic transformation functions in this family, different ones can handle different degrees to which a domain expert is positive or negative when performing such a transformation task. The direct motivation of the investigation lies in a realistic consideration. In the past, expert systems exploited mainly these two models to deal with uncertainties. In other words, a lot of stand-alone expert systems which use the two uncertain reasoning models are available. If there is a reasonable transformation mechanism between these two uncertain reasoning models, we can use the Internet to couple these pre-existing expert systems together so that the integrated systems are able to exchange and share useful information with each other, thereby improving their performance through cooperation. Also, the issue of transformation between heterogeneous uncertain reasoning models is significant in the research area of multi-agent systems because different agents in a multi-agent system could employ different expert systems with heterogeneous uncertain reasonings for their action selections and the information sharing and exchanging is unavoidable between different agents. In addition, we make clear the relationship between the certainty factor model and probability theory.

A study of train group operation multi-agent model oriented RITS

In this paper, aiming at describing interrelationships and communication mechanisms among agents based on a multi-agent framework of Railway Intelligent Transportation System (RITS), we construct the model about stations and trains in the system, which is called Agent-Oriented G-Net Train Group Operation Model (AGNTOM). The framework degrades the complexity of computation and makes the distribution of simulation system easy in design. The simulated experiments prove that the model provides an effective approach for dealing with communication problems in the system.

The differential roles of D-Pax2 variants in regulating Drosophila eye and bristle development

The ability to appropriately interact with the environment is crucial to an organism’s survival. The establishment of functional sensory systems, such as the bristles and eyes in Drosophila, is a critical event during the development of the organism. The transcription factor D Pax2 is involved in the differentiation of the shaft and glial cells in the developing bristle (Kavaler et al., Dev, 126:2261-2272, 1999) and of the cone and primary pigment cells in the developing eye (Fu and Noll, Genes Dev, 11:389-405, 1997). How D-Pax2 contributes to distinct differentiative pathways in different cell types is not known. Recent work by Anna Czechowski and Katherine Harmon (personal communication) identified a mutation in the D-Pax2 gene that introduced a stop codon at the end of exon 9, effectively truncating the protein. This mutation affects bristle, but not eye, development. We thus suspected regions after exon 9 are required for D-Pax2 function only in the bristles and may also be associated with alternative splicing of the D Pax2 transcript. We plan to assess the role of the carboxy terminal region of the protein by establishing transgenic lines bearing rescue constructs of D-Pax2 with either the complete coding sequence or with deletions of specific exons. To date, we have generated the first rescue construct bearing the complete coding region of the gene driven by a 3 KB upstream regulatory region of D-Pax2 and are currently generating transgenic fly lines with this construct.

Skeletal muscle htererogeneity in fasting-induced upregulation of genes encoding UCP2, UCP3, PPARĂ and key enzymes of lipid oxidation

The uncoupling protein homologs UCP2 and UCP3 have been proposed as candidate genes for the regulation of lipid metabolism. Within the context of this hypothesis, we have compared, from fed and fasted rats, changes in gene expression of skeletal muscle UCP2 and UCP3 with those of carnitine palmitoyltransferase I and medium-chain acyl-CoA dehydrogenase, two key enzymes regulating lipid flux across the mitochondrial #-oxidation pathway. In addition, changes in gene expression of peroxisome proliferator-activated receptor gamma, a nuclear transcription factor implicated in lipid metabolism, were also investigated. The results indicate that in response to fasting, the mRNA levels of UCP2, UCP3, carnitine palmitoyltransferase I and medium-chain acyl-CoA dehydrogenase are markedly increased, by three- to sevenfold, in the gastrocnemius and tibialis anterior (fast-twitch muscles, predominantly glycolytic or oxidative-glycolytic), but only mildly increased, by less than twofold, in the soleus (slow-twitch muscle, predominantly oxidative). Furthermore, such muscle-type dependency in fasting-induced transcriptional changes in UCP2, UCP3, carnitine palmitoyltransferase and medium-chain acyl-CoA dehydrogenase persists when the increase in circulating levels of free fatty acids during fasting is abolished by the anti-lipolytic agent nicotinic acid - with blunted responses only in the slow-twitch muscle contrasting with unabated increases in fast-twitch muscles. Independently of muscle type, however, the mRNA levels of peroxisome proliferator-activated receptor gamma are not altered during fasting. Taken together, these studies indicate a close association between fasting-induced changes in UCP2 and UCP3 gene expression with those of key regulators of lipid oxidation, and are hence consistent with the hypothesis that these UCP homologs may be involved in the regulation of lipid metabolism. Furthermore, they suggest that in response to fasting, neither the surge of free fatty acids in the circulation nor induction of the peroxisome proliferator-activated receptor gamma gene may be required for the marked upregulation of genes encoding the UCP homologs and key enzymes regulating lipid oxidation in fast-twitch muscles.

A logical framework for knowledge sharing in multi-agent systems

The issue of knowledge sharing has been an important topic in multi-agent research. Knowledge sharing leads to that agents analyze, judge and synthesize the told information so as to make agents’ own knowledge. To match these applications, this paper builds a logical framework for knowledge sharing among agents. We develop a multimodal logic for reasoning about both agents’ knowledge and told information. For formalizing the relationship between knowledge and told information, we present a framework of semantics, with respect to which a sound and complete proof theory is given.

An agent-based intelligent system for information gathering from world wide web environment

To use the vast amount of information efficiently and effectively from Web sites is very important for making informed decisions. There are, however, still many problems that need to be overcome in the information gathering research arena to enable the delivery of relevant information required by users. In this paper, an information gathering system is develop by means of multiple agents to solve those problems. We employed some ideas of Gaia's methodology and an open agent architecture to analyze and design the system. The system consists of a query preprocessing agent, information retrieval agent, information filtering agent, and information management agent. The filtering agent is trained with categorized documents and can provide users with the necessary information. The experimental results show that all agents in the system can work cooperatively to retrieve relevant information from the World Wide Web environment.

An agent-based framework for petroleum information services from distributed heterogeneous data resources

For making good decisions in the area of petroleum production, it is becoming a big problem how to timely gather sufficient and correct information, which may be stored in databases, data files, or on the World Wide Web. In this paper, Gaia methodology and Open Agent Architecture were employed to contribute a framework to solve above problem. The framework consists of three levels, namely, role mode, agent type, and agent instance. The model with five roles is analyzed. Four agent types are designed Six agent instances are developed for constructing the system of petroleum information services. The experimental results show that all agents in the system can work cooperatively to organize and retrieve relevant petroleum information. The successful implementation of the framework shows that agent-based technology can significantly facilitate the construction of complex systems in distributed heterogeneous data resource environment.

A ring-based architectural model for middle agents in agent-based system

In agent-based systems, the performance of middle agents not only relies on the matchmaking algorithms employed by them, but also the architecture that organizes them with suitable organizational structure and coordination mechanism. In this paper, we contribute a framework and develop a couple of middle agents with logical ring organizational structure to match requester agents with service provider agents. The middle agent is of the features of proliferation and self-cancellation according to the sensory input from its environment. The token-based coordination mechanism of middle agents is designed. Two kinds of middle agents, namely, host and duplicate, are designed for promoting the scalability and robustness of agent-based systems. We demonstrate the potentials of the architecture by case study.

Supporting knowledge management infrastructure : a multi-agent approach

Knowledge management has by now exerted a large influence over industrial practice. We propose a multi-agent based system to provide infrastructure service to meet various requirements of knowledge management in view of the complex nature of the task, i.e., covering science and technologies across different disciplines. The paper discusses the use of a multi-agent system to support the knowledge management infrastructure. It will also discuss the design rational and implementation details as well as an application to the problem of feature extraction in weather prediction.

A scalable and robust framework for agent-based heterogeneous database operation

How to operate database efficiently and unfailingly in agent-based heterogeneous data source environment is becoming a big problem. In this paper, we contribute a framework and develop a couple of agent-oriented matchmakers with logical ring organization structure to match task agents' requests with middleware agents of databases. The middleware agent is a wrapper of a specific database and is run on the same server with the database management system. The matchmaker is of the features of proliferation and self-cancellation according to the sensory input from its environment. The ring-based coordination mechanism of matchmakers is designed. Two kinds of matchmakers, namely, host and duplicate, are designed for improving the scalability and robustness of agent-based system. The middleware agents are improved for satisfying the framework. We demonstrate the potentials of the framework by case study and present theoretical and empirical evidence that our approach is scalable and robust.

A platform for dynamic organization of agents in agent-based systems

In most agent-based systems, different middle agents are employed to increase their flexibility. However, there are still three issues remain unsolved. In centralized architecture with single middle agent, the middle agent itself is a bottleneck and suffers from single point failure; middle agents in distributed architecture lack capability of dynamic organization of agents; The reliability is not strong because of the single point failure and lack of effective architecture. We introduce a platform with ring architectural model to solve all above problems. In the platform, multiple middle agents are dynamically supported for solving the first problem. For solving the second problem, middle agents dynamically manage the registration and cancellation of service provider agents and application teams, each of which includes a set of closely interacting requester agents to complete an independent task. Redundancy middle agent technique is proposed for solving the third problem. All middle agents are of the feature of proliferation and self-cancellation according to the sensory inputs from their environment. For organizing the middle agents effectively, a ring architectural model is proposed. We demonstrate the applicability of the platform by its application and present experimental evidence that the platform is flexible and robust.