Mobile Agent

As the number of mobile nodes registering with a network rapidly increases in Mobile IP, multiple mobility (home or foreign) agents can be allocated to a network in order to improve performance and availability. Previous fault-tolerant schemes (denoted by PRT schemes) to mask failures of the mobility agents use passive replication techniques. However, they result in high failure-free latency during registration process if the number of mobility agents in the same network increases, and force each mobility agent to manage bindings of all the mobile nodes registering with its network. In this paper, we present a new fault-tolerant scheme (denoted by CML scheme) using checkpointing and message logging techniques. The CML scheme achieves low failure-free latency even if the number of mobility agents in a network increases, and improves scalability to a large number of mobile nodes registering with each network compared with the PRT schemes. Additionally, the CML scheme allows each failed mobility agent to recover bindings of the mobile nodes registering with the mobility agent when it is repaired even if all the other mobility agents in the same network concurrently fail.

Abstract—At Delft University of Technology there is a project running on the development of a traffic information-system. The paper presents a using of XML for multimodal communication with an intelligent travel assistant. The personal Intelligent Travel Assistant (PITA) provides the user with a personalized, up-to-date advice on a handheld device, which takes into account actual delays and user preferences. The travelers themselves provide information about delays of trains, using GPS to estimate whether a user is experiencing a ...

The proliferation of small mobile devices and wireless networks has resulted in an increasing demand to support the applications found in wired environments on mobile devices. In real time replication systems, such as collaborative systems, this trend gives some new problems to address. The properties of wireless networks are low bandwidth and high latency, which change dynamically over time. The risk of the network getting congested is therefore high with the result that the user will not receive the important information in ...

In this paper we describe a disaster management system. It is assumed that each individual in the field is equipped with a PDA (Personal Digital Assistant) and that can communicate with other PDAs in the vicinity. Together the PDAs form an ad-hoc network. Users can enter their own observations to the PDA, like the position of victims, or a description of the current situation at particular location (e.g. smoke, emergency exits, traffic congestion). This information is entered in a special iconic language. Reversibly, the PDAs inform the users on the overall current situation of the crisis. In order to come to a shared view of the world, the knowledge that is present in the network has to be shared and fused. The proposed way to communicate is via a shared blackboard. This approach facilitates communication in a time and place independent way.

This paper presents the overall design of a multi-agent framework for tuning the performance of an application executing in a distributed environment. The multi-agent framework provides services like resource brokering, analyzing performance monitoring data, local tuning and also rescheduling in case of any performance problem on a specific resource provider. The paper also briefly describes the implementation of some part of the framework. In particular, job migration on the basis of performance monitoring data is particularly highlighted in this paper.

Jini is able to support applications in heterogeneous, dynamic computing environments and is also being used to develop agent-based applications. This paper presents the design of a multiagent framework for resource brokering and management in a Grid environment and implementation of a part of it utilizing Jini features. The multiagent framework provides services like resource brokering and allocation, analysis of performance-monitoring data, local tuning of applications and also rescheduling in case of any performance problem on a specific resource provider. Part of the framework makes use of mobile agents for scheduling and rescheduling purposes.

The information age is now passing through an evolutionary phase. As the capacity of networks is increasing to handle and process huge volume of information traffic, the management of such information systems is becoming a trivial issue. The Internet being the largest source of information provision is heterogeneous in nature with constantly evolving environment. New information services are added whereas some are modified or removed. User’s demands and interests also change constantly. In such a dynamic environment it is very difficult to maintain a coherent picture of the information services. A novel technique proposed recently employs autonomous mobile agents in faded information field architecture to facilitate information provision and servicing in this new era of information age. The architecture is decentralized in nature whereby both the service provider and information seeker communicate through mobile agents. However, the degree of fairness of information distribution and...

Intelligent mobile agents are today accepted as powerful tools for data mining in a distributed environment. The use of data mining algorithms further beefs up the intelligence in software agents. Knowledge discovery and data mining algorithms are applied to ...

Knowledge management solutions relying on central repositories sometimes have not met expectations, since users often create knowledge adhoc using their individual vocabulary and using their own decentral IT infrastructure (e.g., their laptop). To improve knowledge management for such decentralized and individualized knowledge work, it is necessary to, first, provide a corresponding IT infrastructure and to, second, deal with the harmonization of different vocabularies/ontologies. In this paper, we briefly sketch the technical peer-to-peer platform that we have built, but then we focus on the harmonization of the participating ontologies. Thereby, the objective of this harmonization is to avoid the worst incongruencies by having users share a core ontology that they can expand for local use at their will and individual needs. The task that then needs to be solved is one of distributed, loosely-controlled and evolving engineering of ontologies. We have performed along these lines. To support the ontology engineering process in the case study we have furthermore extended the existing ontology engineering environment, OntoEdit. The case study process and the extended tool are presented in this paper.

Virtual Home Environment (VHE) encompasses the deployment and management of adaptable services that retain any personalized service aspects, irrespective of terminal, network' and geographic location. We assert that the dynamic nature of the VHE requires management capabilities that can be suitably provided through the use of mobile agent technology. We examine four different engineering solutions for the realization of a VHE performance management component that allows service adaptation in relation to the available network Quality-of-Service (QoS). The mobile agent approach is compared with competing technologies in order to identify the benefits of this novel application of mobile agents, discuss its drawbacks' and finally focus on the lessons learned from our prototype system. Although mobile agents are typically associated with increased performance costs, it is through agent migration that we were able to address the VHE requirements of universality, dynamic programmability, and network technology independence.

IP multicast is used to deliver services to groups of users. However, this approach needs an infrastructure support in place, which makes the service not always available. We propose a novel application-level multicast approach based on mobile agents, which does not require any specific layer 3 support and suits the requirements of dynamic networking environments. We present a simulation-based comparative analysis between our approach and DVMRP, focussing on performance and scalability.

Network and service management have attracted a lot of attention in terms of research and standardisation in recent years. Architectural frameworks such as the TMN try to address the management needs of broadband networks and services, catering for multi-domain, multi-operator environments while also allowing for electronic customer access to management services. Similar services will be offered by Internet ISPs in the future, addressing the next generation IP networks with QoS guarantees. These management ...

This paper presents a new multiagent middleware named Siebog, made to provide high performance and platform independence for software agents. This framework was built by combining the features of the Radigost and XJAF agent frameworks. It provides an infrastructural support for both client-side and server-side agents. The clientside agents are written in JavaScript and can be executed on a wide variety of software and hardware platforms, including desktops, smartphones and tablets, and Smart TVs. The server-side agents, on the other hand, can harness the benefits of clustered environments, and rely on automated load-balancing and fault-tolerance for the uninterrupted delivery of services. The two sides of Siebog have been integrated in a way that enables cross-platform messaging, agent code sharing, and even heterogeneous agent mobility.

Consider a stationary agent A at an unknown location and a mobile agent B that must move to the vicinity of and then circumnavigate A at a prescribed distance from A. In doing so, B can only measure its distance from A, and knows its own position in some reference frame. This paper considers this problem, which has applications to surveillance or maintaining an orbit. In many of these applications it is difficult for B to directly sense the location of A, e.g. when all that B can sense is the intensity of a signal emitted by A. This intensity does, however provide a measure of the distance. We propose a nonlinear periodic continuous time control law that achieves the objective. Fundamentally, B must exploit its motion to estimate the location of A, and use its best instantaneous estimate of where A resides, to move itself to achieve the ultimate circumnavigation objective. The control law we propose marries these dual goals and is globally exponentially convergent. We show through simulations that it also permits B to approximately achieve this objective when A experiences slow, persistent and potentially nontrivial drift.

Consider a stationary agent A at an unknown location and a mobile agent B that must move to the vicinity of and then circumnavigate A at a prescribed distance from A. In doing so, B can only measure its distance from A, and knows its own position in some reference frame. This paper considers this problem, which has applications to surveillance or maintaining an orbit. In many of these applications it is difficult for B to directly sense the location of A, e.g. when all that B can sense is the intensity of a signal emitted by A. This intensity does, however provide a measure of the distance. We propose a nonlinear periodic continuous time control law that achieves the objective. Fundamentally, B must exploit its motion to estimate the location of A, and use its best instantaneous estimate of where A resides, to move itself to achieve the ultimate circumnavigation objective. The control law we propose marries these dual goals and is globally exponentially convergent. We show through simulations that it also permits B to approximately achieve this objective when A experiences slow, persistent and potentially nontrivial drift.

Agents' research has been going on for more than two decades now. The idea of improving assistance by agents capable of responding to the needs and emotional states of the users is not new, yet not much has been achieved so far. The main aim of this paper is to describe an intelligent context-aware mobile tour guide, having a biologically inspired architecture of emotion that allows the guide to adapt to the user's needs and feelings. The resulting agent guides visitors touring an outdoor attraction as well as personalises the story presentation. A review of related work is presented, followed by a technical description of the system focusing on the core elementthe guide's emotional architecture and concluded with the current state of the project.

Today product development activities are becoming more and more agile, adaptable, and cost-effective. Multi-agent-based system technology has found wide applications in managing company’s information. This paper applies Multi-mobile-agent technology in developing a collaborative architecture for product lifecycle. By adopting the Aglets mobile agent platform, a generic platform has been developed for managing legacy product data and information across the product lifecycle. Different lifecycle stage product data and information and their interaction and administration are encapsulated, represented and operated with different agents. The system aims to integrate mobile agents into different locations so as to fully utilize the product lifecycle information, and make the product lifecycle decision satisfying the global target of the company. The architecture and the working principle, framework and implementation of the system are addressed in detail. The model of the mobile agents in...

In this paper, we present a software framework, called HDS (Heterogeneous Distributed System), that tries to simplify the realization of distributed applications and, in particular, of multi-agent systems, by: i) abstracting the use of different technologies for the realization of distributed applications on networks of heterogeneous devices connected through a set of different communication transport protocols, ii) merging the client-server and the peer-to-peer paradigms, and iii) implementing all the interactions among the processes of a system through the exchange of typed messages that allow the implementation of a large set of communication protocols and languages.

There are beginning to be a lot of agents executing on the web, and some of them are starting to move around. While most agents are static, in that they exist as a single process or thread on one host computer, others can pick up and move their code and data to a new host in the web, where they then resume executing.

Multiagent-based middleware has emerged as a key technology in the field of distributed systems, gaining considerable attention in recent years. This paper provides an overview of multiagent-based middleware, surveys different types of middleware, explores its applications, and discusses future directions for development. Multiagent-based middleware plays a vital role in helping small and medium-sized enterprises (SMEs) efficiently utilize their information spaces, facilitating communication between various technologies responsible for multiagent systems. JADE, an open-source platform, is a notable example of such middleware. It standardizes multiagent system development and promotes interoperability.The key features of multiagentbased middleware include include autonomy, proactivity, social capabilities, and semantic abstraction. However, challenges like extensibility, operation management, and interoperability remain.Multiagent-based middleware finds applications in diverse domains, such as healthcare, emergency management, and smart homes, where it aids in decision support, coordination, and real-time response. It contributes to the development of intelligent agents and promotes interoperable and scalable technology network architecture.Despite its benefits, multiagent-based middleware faces limitations in addressing the heterogeneity of Machine-to-Machine (M2M) systems and lacks support for semantic and syntactical interoperability. Future developments are needed to overcome these challenges and explore emerging trends, such as the growth of M2M devices, to shape the technology's future.

To realize its promise of providing scaleable and optimal use of network resources, mobile agent technology must be integrated with non-mobile architectures (e.g., client-server) while taking into account the specific needs of applications. This paper introduces a general characterization of mobile agent applications that provides a framework for reasoning about such optimization issues. This framework is refined to enable analysis of alternative mobility policies, and the development of a new strategic mobility policy that uses the application characterization to intelligently decide on mobility. The analysis shows that the extreme cases of 'always mobile' and 'always stationary' are sub-optimal with respect to strategic mobility. Strategic mobility has been implemented in a software prototype called Mobile-AgentX and successfully tested in an application of concurrent engineering of Micro-Electro-Mechanical Systems (MEMS).

We propose a productivity-based account of vagueness. Predicates remain bivalent over the intended universe, but their extensions may be productive, explaining the persistence of borderline cases as a structural failure of effective decidability rather than a semantic gap. We distinguish contrary (term) negation from complementary negation and prove that, for sharp predicates, term negation coincides with logical/complementary negation. We further show an effective obstruction: no effectively enumerable family of precisifications, each providing a c.e. approximation, can capture a productive extension; a uniform escape operator always produces counterexamples. The model yields a dynamic, one‑sided account of vagueness that improves on supervaluationist, fuzzy, and rough‑set approaches by explaining the perpetual emergence of new borderline cases without appealing to a predicate–complement partition.

Abstract—Recent years have seen significant research in finding closed form expressions for the delay of the RLC interconnect which improves upon the Elmore delay model. However, several of these formulae assume a step excitation. But in practice, the input waveform does have a non zero time of flight. There are few works reported so far which do consider the ramp inputs but lacks in the explicit nature which could work for a wide range of possible input slews. Elmore delay has been widely used as an analytical estimate of ...

There has been a growing interest in mobile, multi-hop wireless networks in recent years. One of the major concerns in this context is to design a communication protocol that provides QoS guarantee. Because of mobility, a node involved in the communication process may move out of the fixed transmission range of the sender, thus disturbing the communication process. In this paper, a mechanism is proposed based on self-adjusting variable transmission range of mobile hosts, which will not allow this to happen during a communication process. At the same time, variable transmission range of mobile hosts will allow us to control the congestion of control packets in a dynamic setting which would in turn reduce the end-to-end delay in data communication.

Supporting high volume of data transmission in a highly dynamic architecture like Mobile Ad hoc Networks (MANET) still remains a major point of research. In this paper, we have attempted to address the issue of managing an uninterrupted connection between a source and a destination through multiple paths in a temporal domain. We have developed an agent-centric protocol that would accomplish uninterrupted communication over adaptively selected routes. The protocol ensures minimal consumption of network resources. We have organized this work in two logical steps. In the first part, we have described an agent-based framework with its associated protocols and mechanisms. The primary objective of this mobile multiagent framework is to make all nodes in the system topology-aware. We have used the GPS (Global Positioning System) support at each node for the extraction of geographical coordinates, velocity, and direction of movement of each node. The second part of the work attempts to make...

We consider the map construction problem in a simple, connected graph by a set of mobile computation entities or agents that start from scattered locations throughout the graph. The problem is further complicated by dangerous elements, nodes and links, in the graph that eliminate agents traversing or arriving at them. The agents working in the graph communicate using a limited amount of storage at each node and work asynchronously. We present a deterministic algorithm that solves the exploration and map construction problems. The end result is also a rooted spanning tree and the election of a leader. The total cost of the algorithm is O(n s m) total number of moves, where m is the number of links in the network and n s is the number of safe nodes, improving the existing O(m 2 ) bound.

Consider a networked environment, supporting mobile agents, where there is a black hole: a harmful host that disposes of visiting agents upon their arrival, leaving no observable trace of such a destruction. The black hole search problem is the one of assembling a team of asynchronous mobile agents, executing the same protocol and communicating by means of whiteboards, to successfully identify the location of the black hole; we are concerned with solutions that are generic (i.e., topology-independent). We establish tight bounds on the size of the team (i.e., the number of agents), and the cost (i.e., the number of moves) of a size-optimal solution protocol. These bounds depend on the a priori knowledge the agents have about the network, and on the consistency of the local labellings. In particular, we prove that: with topological ignorance ∆ + 1 agents are needed and suffice, and the cost is Θ(n 2 ), where ∆ is the maximal degree of a node and n is the number of nodes in the network; with topological ignorance but in presence of sense of direction only two agents suffice and the cost is Θ(n 2 ); and with complete topological knowledge only two agents suffice and the cost is Θ(n log n). All the upper-bound proofs are constructive.

A black hole is a highly harmful host that disposes of visiting agents upon their arrival. It is known that it is possible for a team of mobile agents to locate a black hole in an asynchronous ring network if each node is equipped with a whiteboard of at least O(log n) dedicated bits of storage. In this paper, we consider the less powerful token model: each agent has has available a bounded number of tokens that can be carried, placed on a node or removed from it. All tokens are identical (i.e., indistinguishable) and no other form of communication or coordination is available to the agents. We first of all prove that a team of two agents is sufficient to locate the black hole in finite time even in this weaker coordination model. Furthermore, we prove that this can be accomplished using only O(n log n) moves in total, which is optimal, the same as with whiteboards. Finally, we show that to achieve this result the agents need to use only O(1) tokens each.

In this paper we consider a dangerous process located at a node of a network (called Black Hole ) and a team of mobile agents deployed to locate that node. The nature of the danger is such that when an agent enters the dangerous node, it is trapped there leaving no trace of its destruction. The goal is to deploy as few agents as possible and to locate the black hole in as few moves as possible. We present a simple algorithm that works on any topology (a-priori known by the agents). Our algorithm, based on the pre-computation of an open vertex cover by cycles of the network, uses the optimal number of agents (two); its cost (number of moves) depends on the choice of the cover and it is optimal for several classes of networks.

Consider a team of (one or more) mobile agents operating in a graph G. Unaware of the graph topology and starting from the same node, the team must explore the graph. This problem, known as graph exploration, was initially formulated by Shannon in 1951, and has been extensively studied since under a variety of conditions. The existing investigations have all assumed that the network is safe for the agents, and the solutions presented in the literature succeed in their task only under this assumption. Recently, the exploration problem has been examined also when the network is unsafe. The danger examined is the presence in the network of a black hole, a node that disposes of any incoming agent without leaving any observable trace of this destruction. The goal is for at least one agent to survive and to have all the surviving agents to construct a map of the network, indicating the edges leading to the black hole. This variant of the problem is also known as black hole search. This problem has been investigated assuming powerful inter-agent communication mechanisms: whiteboards at all nodes. Indeed, in this model, the black hole search problem can be solved with a minimal team size and performing a polynomial number of moves. In this paper, we consider a less powerful token model. We constructively prove that the black hole search problem can be solved also in this model; furthermore, this can be done using a minimal team size and performing a polynomial number of moves. Our algorithm works even if the agents are asynchronous and if both the agents and the nodes are anonymous.

A black hole is a harmful host that destroys incoming agents without leaving any observable trace of such a destruction. The black hole search problem is to unambiguously determine the location of the black hole. A team of agents, provided with a network map and executing the same protocol, solves the problem if at least one agent survives and, within finite time, knows the location of the black hole. It is known that a team must have at least two agents. Interestingly, two agents with a map of the network can locate the black hole with O(n) moves in many highly regular networks; however the protocols used apply only to a narrow class of networks. On the other hand, any universal solution protocol must use Ω(n log n) moves in the worst case, regardless of the size of the team. A universal solution protocol has been recently presented that uses a team of just two agents with a map of the network, and locates a black hole in at most O(n log n) moves. Thus, this protocol has both optimal size and worst-case-optimal cost. We show that this result, far from closing the research quest, can be significantly improved. In this paper we present a universal protocol that allows a team of two agents with a network map to locate the black hole using at most O(n + d log d) moves, where d is the diameter of the network. This means that, without losing its universality and without violating the worst-case Ω(n log n) lower bound, this algorithm allows two agents to locate a black hole with Θ(n) cost in a very large class of (possibly unstructured) networks.

Consider a networked environment, supporting mobile agents, where there is a black hole: a harmful host that disposes of visiting agents upon their arrival, leaving no observable trace of such a destruction. The black hole search problem is the one of assembling a team of asynchronous mobile agents, executing the same protocol and communicating by means of whiteboards, to successfully identify the location of the black hole; we are concerned with solutions that are generic (i.e., topology-independent). We establish tight bounds on the size of the team (i.e., the number of agents), and the cost (i.e., the number of moves) of a size-optimal solution protocol. These bounds depend on the a priori knowledge the agents have about the network, and on the consistency of the local labellings. In particular, we prove that: with topological ignorance ∆ + 1 agents are needed and suffice, and the cost is Θ(n 2 ), where ∆ is the maximal degree of a node and n is the number of nodes in the network; with topological ignorance but in presence of sense of direction only two agents suffice and the cost is Θ(n 2 ); and with complete topological knowledge only two agents suffice and the cost is Θ(n log n). All the upper-bound proofs are constructive.

We prove that, for the black hole search problem, the pure token model is computationally as powerful as the whiteboard model; furthermore the complexity is exactly the same. More precisely, we prove that a team of two asynchronous agents, each endowed with a single identical pebble (that can be placed only on nodes, and with no more than one pebble per node) can locate the black hole in an arbitrary network of known topology; this can be done with Θ(n log n) moves, where n is the number of nodes, even when the links are not FIFO.

The Rendezvous of anonymous mobile agents in a anonymous network is an intensively studied problem; it calls for k anonymous, mobile agents to gather in the same site. We study this problem when in the network there is a black hole: a stationary process located at a node that destroys any incoming agent without leaving any trace. The presence of the black hole makes it clearly impossible for all agents to rendezvous. So, the research concern is to determine how many agents can gather and under what conditions. In this paper we consider k anonymous, asynchronous mobile agents in an anonymous ring of size n with a black hole; the agents are aware of the existence, but not of the location of such a danger. We study the rendezvous problem in this setting and establish a complete characterization of the conditions under which the problem can be solved. In particular, we determine the maximum number of agents that can be guaranteed to gather in the same location depending on whether k or n is unknown (at least one must be known for any nontrivial rendezvous). These results are tight: in each case, rendezvous with one more agent is impossible. All our possibility proofs are constructive: we provide mobile agents protocols that allow the agents to rendezvous or near-gather under the specified conditions. The analysis of the time costs of these protocols show that they are optimal. Our rendezvous protocol for the case when k is unknown is also a solution for the black hole location problem. Interestingly, its bounded time complexity is Θ(n); this is a significant improvement over the O(n log n) bounded time complexity of the existing protocols for the same case.

We prove that, for the black hole search problem in networks of arbitrary but known topology, the pebble model of agent interaction is computationally as powerful as the whiteboard model; furthermore the complexity is exactly the same. More precisely, we prove that a team of two asynchronous agents, each endowed with a single identical pebble (that can be placed only on nodes, and with no more than one pebble per node), can locate the black hole in an arbitrary network of known topology; this can be done with Θ(n log n) moves, where n is the number of nodes, even when the links are not FIFO. These results are obtained with a novel algorithmic technique, ping-pong, for agents using pebbles.

Management of large-scale Network-Centric Systems (NCS) and their applications is an extremely complex and challenging task due to factors such as centralized management architectures, lack of coordination and compatibility among heterogeneous network management systems, and the dynamic characteristics of networks and application bandwidth requirements, just to name a few. The goal of this research is to develop a hierarchical framework to achieve end-to-end intelligent proactive network management system that can be used to manage largescale network centric systems and their applications. This framework will provide the ability to write management programs to manage any required function or property (performance, high assurance, fault, quality of service, etc.) o f the network-centric systems and their applications during all the phases of their operations. Our ultimate objective is to consider the management of network-centric systems and applications starting from the design phase and forward rather than being after thought process. In this paper, we present a framework to develop proactive and adaptive management services and an implementation of a Proactive Application Management System (PAMS) based on that framework. Our implementation approach utilizes delegated mobile agents to implement the management functions required by any network-centric system and/or application. We will also present experimental results and evaluation of the management services offered by the PAMS prototype.

Management of large-scale Network-Centric Systems (NCS) and their applications is an extremely complex and challenging task due to factors such as centralized management architectures, lack of coordination and compatibility among heterogeneous network management systems, and the dynamic characteristics of networks and application bandwidth requirements, just to name a few. The goal of our research is to develop a hierarchical framework to achieve end-to-end intelligent proactive network management system that can be used to manage large scale network centric systems and their applications. This framework will provide the appropriate tools to write management programs to control and manage any function or property (performance, high assurance, fault, quality of service, etc.) of the network-centric systems and their applications during all the phases of their operations. In this paper, we present a framework to develop proactive and adaptive management services and an implementation of a Proactive Application Management System (PAMS) based on that framework. Our implementation approach utilizes delegated mobile agents to implement the management functions required by any network-centric system and/or application. We also present experimental results and evaluation of the management services offered by the PAMS prototype.

The ACM module provides the application developers with all the tools required to specify the appropriate management schemes to manage any quality of service requirement or application attribute/functionality (e.g., performance, fault, security, etc.). The MCS provides the core management services to enable the efficient proactive management of a wide range of network applications. The services offered by the MCS are implemented using mobile agents. Furthermore, each MCS service can be implemented using several techniques that can be selected dynamically by invoking the corresponding mobile agent template for the service implementation. In this paper, we present our preliminary results of evaluating PAMS management services to manage the performance and fault tolerance execution of three applications of different sizes (small, medium and large). The experimental results demonstrate that our agent-based approach can lead to significant gains in the performance and low overhead fault management of parallel/distributed. For example, the overhead incurred in the application fault management to tolerate one task failure, two task failures, and three task failures in a medium to large size application is less than 0.02%.

This paper presents a strategy for the support of Personal Communication Services in TINA compliant systems through the use of mobile agents. The paper reflects the vision of the EC/ACTS research project DOLMEN that has developed OSAM, an Open Service Architecture for fixed and Mobile environments. After introducing the principle of retailer federation in a multi-domain environment, the paper analyses how federation can be established to support migration of agents acting on behalf of the user within the network. Moreover, a strategy for mobile agents allocation is presented and its effectiveness is evaluated according to two different performance metrics: the signalling load on the network and the average response time for service requests.

This paper describes the role of agent in distributed data mining, comparison of various agent frameworks and also focusses on jade agent framework as a suitable framework for distributed data mining and discovery of patterns from multi agent systems. In this paper, overview of JADE architecture and basic steps to develop agents are described. The paper also focusses on implementing association rule mining algorithm-Apriori on JADE agent framework and result has been generated.

Now a day's Heterogeneous wireless network is a promising field of research interest. Various challenges exist in this hybrid combination like load balancing, resource management and so on. In this paper we introduce a reliable load balancing architecture for heterogeneous wireless communications to ensure certain level of quality of service. To conquer the problem of centralized and distributed design, a semidistributed load balancing architecture for multiple access networks is introduced. In this grid based design multiple Load and Mobile Agent Management Units is incorporated. To prove the compactness of the design, integrated reliability, signalling overhead and total processing time is calculated. And finally simulation result shows that overall system performance is improved by enhancing reliability, reducing signalling overhead and processing time.

The broadcast nature of wireless network makes traditional link-layer attacks readily available to anyone within the range of the network. User authentication is best safeguard against the risk of unauthorized access to the wireless networks. The present 802.1× authentication scheme has some flaws, making mutual authentication impossible and open to man-in-the-middle attacks. These characteristics make traditional cryptographic mechanism provide weak security for the wireless environment. We have proposed the use of mobile agents to provide dependable Internet services delivery to users, this will guarantee secure authentication in wireless networks and we examine the feasibility of our solution and propose a model for wireless network security.

Steady-state egress of hematopoietic progenitor cells can be rapidly amplified by mobilizing agents such as AMD3100, the mechanism, however, is poorly understood. We report that AMD3100 increased the homeostatic release of the chemokine SDF-1 to the circulation in mice and non-human primates. Neutralizing antibodies against CXCR4 or SDF-1 inhibited both steadystate and AMD3100-induced SDF-1 release and reduced egress of murine progenitor cells over mature leukocytes. Intra-bone injection of biotinylated SDF-1 also enhanced release of this chemokine and murine progenitor cell mobilization. AMD3100 directly induced SDF-1 release from CXCR4 + human bone marrow osteoblasts and endothelial cells and activated uPA in a CXCR4/JNK-dependent manner. Additionally, ROS inhibition reduced AMD3100-induced SDF-1 release, activation of circulating uPA and mobilization of progenitor cells. Norepinephrine treatment, mimicking acute stress, rapidly increased SDF-1 release and progenitor cell mobilization, while β2-adrenergic antagonist inhibited both steady-state and AMD3100-induced SDF-1 release and progenitor cell mobilization in mice. In conclusion, this study reveals that

Recent advances of computing and networking technology have shifted computing convention from stationary to mobile. A forecast conducted by Gartner indicates that global mobile handset sales will increase exponentially in 2008 by 10% from 1.3 billion units in 2007 [13]. Furthermore, the popularity of wireless networking topology including both Wi-Fi access point and cellular mobile telecommunications enables users with constant access to online connection and further intensifies the demand of mobile devices. This provides the fundamental elements for creating ubiquitous environments of computing, networking, and interfacing that is both aware of and reactive to the presence of people. Such an environment is defined as Ambient Intelligence (AmI). Existing approaches that attempt to understand AmI environment mainly focus on how to seamlessly integrate hardware, i.e. mobile device and sensors, into human society and intelligently provide personalized knowledge and services. This has, however, left many essential issues unanswered, especially in regards to the integrity and performance of such dynamically distributed environments. In this chapter, we formulate a generic framework in which an AmI environment is generalized to consist only of users with devices, hosts where services are provided, and directory servers that act as information desks to users and hosts. In the proposed framework, the mobile agent notion is utilized to provide autonomous reasoning, learning, mobility, and collaboration features to construct AmI systems. Performance issues of load balancing and communication overhead in such a framework are then examined and analyzed against existing AmI techniques. Because of the dynamicity posed by AmI environments and the complexity of migrations and communications among agents, hosts and directory servers, it is necessary to provide a mechanism to warrant the accuracy and enhance the reliability of such an environment. Software verification employs formal methods of mathematically provable formulations to perform program analysis and model checking. Thus, general formulation using π-calculus is included to model the proposed approach to provide verification mechanism. In conclusion, the implementation of the proposed framework simulation using NetLogo is currently ongoing to visually demonstrate its feasibility. Some implementation details are included to stimulate comprehension of this framework.

The purpose of this paper is to introduce an innovative framework for implementation of ambient intelligence (AmI) environments. Compared to the existing state-of-the-art approaches, this framework creates a more decentralized and distributed AmI environment. In addition, the proposed approach is not limited to one specific domain, unlike many others. The openness of the presented architecture allows it to support a variety of devices ranged from small-embedded sensors to complex computing facilities. Finally, given that this approach is formulated based on multi-agent standard concepts, it can be easily implemented as add-on for existing software agent platforms to achieve rapid deployment. Implications for the development of this framework and future directions are discussed.

Software agents extend the current, information-based Internet to include autonomous mobile processing. In most countries such processes, i.e. software agents are, however, without an explicit legal status. Many of the legal implications of their actions (e.g. gathering information, negotiating terms, performing transactions) are not well understood. One important characteristic of mobile software agents is that they roam the Internet: they often run on agent platforms of others. There often is no pre-existing relation between the 'owner' of a running agent's process and the owner of the agent platform on which an agent process runs. When conflicts arise, the position of the agent platform owner is not clear: is he or she allowed to slow down the process or possibly remove it from the system? Can the interests of the user of the agent be protected? This article explores legal and technical perspectives in protecting the integrity and availability of software agents and agent platforms.

The paper is devoted to scheduling with AND/OR precedence constraints. The events are nodes of a certain graph, while the precedence relation is defined by its edges. The non-negative edge weights represent delays. An event of type AND may happen only after all its preceding events have happened, with the corresponding delays after them. An event of type OR may happen only after at least one of its preceding events has happened, with the corresponding delay after it. The early schedule is in question. We present an algorithm for the general AND/OR scheduling problem, where cycles consisting of zero weighted edges only are allowed and the precedence graph is arbitrary. The running time is O(|V ||E|), for a graph G = (V, E). Department of Computer Science, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105 Israel. E-mail: carmip@cs.bgu.ac.il. Department of Computer Science, Ben-Gurion University of the Negev, POB 653, Beer-Sheva 84105 Israel. E-mail: dinitz@cs.bgu.ac.il. Hy...