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Wyniki wyszukiwania dla: mobile agents
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Clearing directed subgraphs by mobile agents
PublikacjaWe study several problems of clearing subgraphs by mobile agents in digraphs. The agents can move only along directed walks of a digraph and, depending on the variant, their initial positions may be pre-specified. In general, for a given subset S of vertices of a digraph D and a positive integer k, the objective is to determine whether there is a subgraph H=(V,A) of D such that (a) S is a subset of V, (b) H is the union of k directed...
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Decontaminating Arbitrary Graphs by Mobile Agents: a Survey
PublikacjaA team of mobile agents starting from homebases need to visit and clean all nodes of the network. The goal is to find a strategy, which would be optimal in the sense of the number of needed entities, the number of moves performed by them or the completion time of the strategy. Currently, the field of distributed graph searching by a team of mobile agents is rapidly expanding and many new approaches and models are being presented...
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Rendezvous of heterogeneous mobile agents in edge-weighted networks
PublikacjaWe introduce a variant of the deterministic rendezvous problem for a pair of heterogeneous agents operating in an undirected graph, which differ in the time they require to traverse particular edges of the graph. Each agent knows the complete topology of the graph and the initial positions of both agents. The agent also knows its own traversal times for all of the edges of the graph, but is unaware of the corresponding traversal...
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Rendezvous of Distance-Aware Mobile Agents in Unknown Graphs
PublikacjaWe study the problem of rendezvous of two mobile agents starting at distinct locations in an unknown graph. The agents have distinct labels and walk in synchronous steps. However the graph is unlabelled and the agents have no means of marking the nodes of the graph and cannot communicate with or see each other until they meet at a node. When the graph is very large we want the time to rendezvous to be independent of the graph size...
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Gossiping by energy-constrained mobile agents in tree networks
PublikacjaEvery node of an edge-weighted tree network contains a data packet. At some nodes are placed mobile agents, each one possessing an amount of energy (not necessarily the same for all agents). While walking along the network, the agents spend the energy proportionally to the distance traveled and collect copies of the data packets present at the visited network nodes. An agent visiting a node deposits there copies of all currently...
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Rendezvous of Heterogeneous Mobile Agents in Edge-Weighted Networks
PublikacjaWe introduce a variant of the deterministic rendezvous problem for a pair of heterogeneous agents operating in an undirected graph, which differ in the time they require to traverse particular edges of the graph. Each agent knows the complete topology of the graph and the initial positions of both agents. The agent also knows its own traversal times for all of the edges of the graph, but is unaware of the corresponding traversal...
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Quantum strategies for rendezvous and domination tasks on graphs with mobile agents
PublikacjaThis paper explores the application of quantum nonlocality, a renowned and unique phenomenon acknowledged as a valuable resource. Focusing on an alternative application, we demonstrate its quantum advantage for mobile agents engaged in specific distributed tasks without communication. The research addresses the significant challenge of rendezvous on graphs and introduces a distributed task for mobile agents grounded in the graph...
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A Review of Traffic Analysis Attacks and Countermeasures in Mobile Agents' Networks
PublikacjaFor traditional, message-based communication, traffic analysis has been already studied for over three decades and during that time various attacks have been recognised. As far as mobile agents’ networks are concerned only a few, specific-scope studies have been conducted. This leaves a gap that needs to be addressed as nowadays, in the era of Big Data, the Internet of Things, Smart Infrastructures and growing concerns for privacy,...
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An untraceability protocol for mobile agents and its enhanced security study
PublikacjaArtykuł przedstawia rozszerzoną analizę bezpieczeństwa zaproponowanego przez nas protokołu ochrony przed tropieniem (ang. untraceability protocol) dla agentów mobilnych. Jak dotąd, tak systematyczna analiza bezpieczeństwa nie została przeprowadzona. Co więcej, istniejące znane analizy bezpieczeństwa koncentrują się wyłącznie na atakujących wewnętrznych. Uważamy, że stworzona przez nas lista kontrolna ataków może posłużyć jako...
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Performance analysis of untraceability protocols for mobile agents using an adaptable framework
PublikacjaArtykuł przedstawia środowisko oceny wydajności protokołów ochrony przed tropieniem agentów mobilnych oraz wyniki analiz przeprowadzonych za jego pomocą. Chociaż środowisko projektowano i implementowano z myślą o ewaluacji zaproponowanych przez nas protokołów ochrony przed tropieniem, w trakcie badań okazało się, że może ono zostać również wykorzystane do badań całej klasy protokołów bezpieczeństwa dla agentów mobilnych. Chodzi...
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Entangled rendezvous: a possible application of Bell non-locality for mobile agents on networks
PublikacjaRendezvous is an old problem of assuring that two or more parties, initially separated, not knowing the position of each other, and not allowed to communicate, are striving to meet without pre-agreement on the meeting point. This problem has been extensively studied in classical computer science and has vivid importance to modern and future applications. Quantum non-locality, like Bell inequality violation, has shown that in many...
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Mobile chromatographs and spectrometers for the analysis of chemical warfare agents
PublikacjaThis article describes the technological state of readiness regarding mobile chromatographs and spectrometers and their appiicability for the analysis of chemical warfare agents (CWAs), degradation products, simulants, and precursors.
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Concept of the mobile monitoring system for chemical agents control in the air
PublikacjaW artykule przedstawiono koncepcję mobilnego systemu monitoringu związków chemicznych zanieczyszczających powietrze. Nowością w przedstawionej koncepcji monitoringu jest pomiar zanieczyszczeń powietrza wzdłuż ciągów komunikacyjnych, co do tej pory nie jest realizowane. W tym celu przedstawiono propozycję rozwiązania stosunkowo małego, bezobsługowego modułu do pomiarów związków chemicznych, który z łatwością będzie montowany na...
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Collaborative Exploration of Trees by Energy-Constrained Mobile Robots
PublikacjaWe study the problem of exploration of a tree by mobile agents (robots) that have limited energy. The energy constraint bounds the number of edges that can be traversed by a single agent. We use a team of agents to collectively explore the tree and the objective is to minimize the size of this team. The agents start at a single node, the designated root of the tree and the height of the tree is assumed to be less than the energy...
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MAlSim - Mobile Agent Malware Simulator
PublikacjaOne of the problems related to the simulation of attacks against critical infrastructures is the lack of adequate tools for the simulation of malicious software (malware). Malware attacks are the most frequent in the Internet and they pose a serious threat against critical networked infrastructures. To address this issue we developed Mobile Agent Malware Simulator (MAISim). The framework uses the technology of mobile agents and...
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Agent System for Managing Distributed Mobile Interactive Documents
PublikacjaThe MIND architecture of distributed mobile interactive document is a new processing model defined for facilitate informed decision-making in non-algorithmic decision-making processes carried out by knowledge-based organizations. The aim of this architecture is to change the static document to mobile agents, which are designed to implement the structure of the organization through autonomous migration between knowledge workers...
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Leader election for anonymous asynchronous agents in arbitrary networks
PublikacjaWe consider the problem of leader election among mobile agents operating in an arbitrary network modeled as an undirected graph. Nodes of the network are unlabeled and all agents are identical. Hence the only way to elect a leader among agents is by exploiting asymmetries in their initial positions in the graph. Agents do not know the graph or their positions in it, hence they must gain this knowledge by navigating in the graph...
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Agent System for Managing Distributed Mobile Interactive Documents in Knowledge-Based Organizations
PublikacjaThe MIND architecture of distributed mobile interactive document is a new processing model defined to facilitate obtaining a proper solution in knowledge processes carried out by knowledge-based organizations. Such organizations have an established structure that defines document templates and knowledge process. The aim of the MIND architecture is to change the static document to mobile agents, which are designed to implement the...
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Mobile monitoring system for gaseous air pollution
PublikacjaThe concept of a mobile monitoring system for chemical agents control in the air is presented. The proposed system can be applied to measure industrial and car traffic air pollution. A monitoring station is relatively small and can be placed on cars or public transportation vehicles. Measured concentrations of air pollutants are collected and transferred via the GSM network to a central data base. Exemplary results from a measurement...
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Deterministic rendezvous of asynchronous bounded-memory agents in polygonal terrains
PublikacjaTwo mobile agents, modeled as points starting at differentlocations of an unknown terrain, have to meet. The terrain is a polygon with polygonal holes. We consider two versions of this rendezvous problem: exact RV, when the points representing the agents have to coincide at some time, and epsilon-RV, when these points have to get at distance less than epsilon in the terrain. In any terrain, each agent chooses its trajectory, but...
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Collision-free network exploration
PublikacjaMobile agents start at different nodes of an n-node network. The agents synchronously move along the network edges in a collision-free way, i.e., in no round two agents may occupy the same node. An agent has no knowledge of the number and initial positions of other agents. We are looking for the shortest time required to reach a configuration in which each agent has visited all nodes and returned to its starting location. In...
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Distributed Evacuation in Graphs with Multiple Exits
PublikacjaWe consider the problem of efficient evacuation using multiple exits. We formulate this problem as a discrete problem on graphs where mobile agents located in distinct nodes of a given graph must quickly reach one of multiple possible exit nodes, while avoiding congestion and bottlenecks. Each node of the graph has the capacity of holding at most one agent at each time step. Thus, the agents must choose their movements strategy...
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How to meet when you forget: log-space rendezvous in arbitrary graphs
PublikacjaTwo identical (anonymous) mobile agents start from arbitrary nodes in an a priori unknown graph and move synchronously from node to node with the goal of meeting. This rendezvous problem has been thoroughly studied, both for anonymous and for labeled agents, along with another basic task, that of exploring graphs by mobile agents. The rendezvous problem is known to be not easier than graph exploration. A well-known recent result...
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Time versus space trade-offs for randezvous in trees
PublikacjaTwo identical (anonymous) mobile agents start from arbitrary nodes of an unknown tree and have to meet at some node. Agents move in synchronous rounds: in each round an agent can either stay at the current node or move to one of its neighbors. We consider deterministic algorithms for this rendezvous task. The main result of this paper is a tight trade-off between the optimal time of completing rendezvous and the size of memory...
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Collision-Free Network Exploration
PublikacjaA set of mobile agents is placed at different nodes of a n-node network. The agents synchronously move along the network edges in a collision-free way, i.e., in no round may two agents occupy the same node. In each round, an agent may choose to stay at its currently occupied node or to move to one of its neighbors. An agent has no knowledge of the number and initial positions of other agents. We are looking for the shortest possible...
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The Snow Team Problem
PublikacjaWe study several problems of clearing subgraphs by mobile agents in digraphs. The agents can move only along directed walks of a digraph and, depending on the variant, their initial positions may be pre-specified. In general, for a given subset~$\cS$ of vertices of a digraph $D$ and a positive integer $k$, the objective is to determine whether there is a subgraph $H=(\cV_H,\cA_H)$ of $D$ such that (a) $\cS \subseteq \cV_H$, (b)...
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Application of genetic algorithms in graph searching problem
PublikacjaGraph searching is a common approach to solving a problem of capturing a hostile intruder by a group of mobile agents. We assume that this task is performed in environment which we are able to model as a graph G. The question asked is how many agents are needed to capture an arbitrary fast, invisible and smart intruder. This number is called the (edge) search number of G. The strategy which must be performed by agents is called...
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Bilateral Multi-Issue Negotiation Between Active Documents and Execution Devices
PublikacjaMobile document-agents are often in conflict with execution devices when attempting to perform activities of the business process they implement, since preferences of device owners may change depending on their current location and the actual class of the device in use. The paper proposes a bilateral negotiation mechanism based on a simple bargaining game that can effectively resolve such conflicts without any third party support.
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Simulating Malware with MAlSim
PublikacjaThis paper describes MAlSim - Mobile Agent Malware Simulator - a mobile agent framework developed to address one of the most important problems related to the simulation of attacks against information systems i.e. the lack of adequate tools for reproducing behaviour of malicious software (malware). The framework can be deployed over the network of an arbitrary information system and it aims at simulating behaviour of each instance...
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Simulating malware with MAlSim
PublikacjaThis paper describes MAlSim - Mobile Agent Malware Simulator - a mobile agent framework developed to address one of the most important problems related to the simulation of attacks against information systems, i.e. the lack of adequate tools for reproducing behaviour of malicious software (malware). The framework can be deployed over the network of an arbitrary information system and it aims at simulating behaviour of each instance...
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Connected searching of weighted trees
PublikacjaW artykule rozważamy problem spójnego przeszukiwania drzew obciążonych. Autorzy w [L. Barriere i inni, Capture of an intruder by mobile agents, SPAA'02 (2002) 200-209] twierdzą, że istnieje wielomianowy algorytm dla problemu obliczania optymalnej strategii przeszukiwania obciążonego drzewa. W niniejszej pracy pokazano, że problem ten jest obliczeniowo trudny nawet dla wierzchołkowo-obciążonych drzew (wagi krawędzi równe 1) oraz...
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Multi-agent graph searching and exploration algorithms
PublikacjaA team of mobile entities, which we refer to as agents or searchers interchangeably, starting from homebases needs to complete a given task in a graph.The goal is to build a strategy, which allows agents to accomplish their task. We analyze strategies for their effectiveness (e.g., the number of used agents, the total number of performed moves by the agents or the completion time).Currently, the fields of on-line (i.e., agents...
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Model otwartej architektury rozproszonych dokumentów elektronicznych wspierającej proces podejmowania decyzji w trybie obliczeń zespołowych
PublikacjaModel otwartej architektury mobilnych dokumentów interaktywnych MIND, został opracowany w celu efektywnego zarządzania informacją w procesach podejmowanych przez organizacje oparte na wiedzy. Architektura ta stanowi całościowy opis struktury i funkcjonalności dokumentu, zaprojektowanego w celu realizacji rozproszonego przetwarzania zespołowego i pracy grupowej. Umożliwia automatyczne przejście od statycznej postaci dokumentów...
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Computational Approaches to Modeling Artificial Emotion – An Overview of the Proposed Solutions
PublikacjaCybernetic approach to modeling artificial emotion through the use of different theories of psychology is considered in this paper, presenting a review of twelve proposed solutions: ActAffAct, FLAME, EMA, ParleE, FearNot!, FAtiMA, WASABI, Cathexis, KARO, MAMID, FCM, and xEmotion. The main motivation for this study is founded on the hypothesis that emotions can play a definite utility role of scheduling variables in the construction...
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On-line Search in Two-Dimensional Environment
PublikacjaWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. As a way of modeling two-dimensional shapes, we restrict our attention to networks that are embedded into partial grids:...
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On-line Search in Two-Dimensional Environment
PublikacjaWe consider the following on-line pursuit-evasion problem. A team of mobile agents called searchers starts at an arbitrary node of an unknown network. Their goal is to execute a search strategy that guarantees capturing a fast and invisible intruder regardless of its movements using as few searchers as possible. We require that the strategy is connected and monotone, that is, at each point of the execution the part of the graph...
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Software Agents for Computer Network Security
PublikacjaThe chapter presents applications of multi-agent technology for design and implementation of agent-based systems intended to cooperatively solve several critical tasks in the area of computer network security. These systems are Agent-based Generator of Computer Attacks (AGCA), Multi-agent Intrusion Detection and Protection System (MIDPS), Agent-based Environment for Simulation of DDoS Attacks and Defense (AESAD) and Mobile Agent...
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BeesyBees: A mobile agent-based middleware for a reliable and secure execution of service-based workflow applications in BeesyCluster
PublikacjaIntegrating distributed services into workflows comes with its own set of challenges, including security, coordination, fault tolerance and optimisation of execution time. This paper presents an architecture and implementation - nicknamed BeesyBees - that allows distributed execution of workflow applications in BeesyCluster using agents. BeesyCluster is a middleware that allows users to access distributed resources as well as publish...
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Effect of User Mobility upon Trust Building among Autonomous Content Routers in an Information-Centric Network
PublikacjaThe capability of proactive in-network caching and sharing of content is one of the most important features of an informationcentric network (ICN). We describe an ICN model featuring autonomous agents controlling the content routers. Such agents are unlikely to share cached content with other agents without an incentive to do so. To stimulate cooperation between agents, we adopt a reputation and trust building scheme that is able...
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Deterministic rendezvous of asynchronous bounded-memory agents in polygonal terrains
PublikacjaWe consider two versions of the rendezvous problem: exact RV, when the points representing agents have to coincide at some time, and e-RV, when these points have to get at distance less than e in the terrain. In any terrain, each agent chooses its trajectory, but the movements of the agent on this trajectory are controlled by an adversary that may, e.g. speed up or slow down the agent.
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Bilateral multi-issue negotiation of execution contexts by proactive document agents
PublikacjaA proactive document can react to its actual environment by autonomously selecting and performing actions integrated into its body and interact with its user. When migrating over a network of execution devices it may encounter diverse execution contexts, each one set up according to temporal characteristics of a receiving device and preferences of its owner. A concept to augment proactive documents with negotiation capability is...