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Currently, the 3DGIS on the web can not meet the requirement of many applications because of the low network bandwidth, the large amount data involved, and the need of high speed of data transportation. To resolve the problems, in this paper, the on-line 3DGIS based on P2P agent distributed computing environment is proposed. We designed the tile-based 3D terrain and the mechanism of the distribution and management of 3DGIS data on P2P agent environment. We also proposed data searching and transmission algorithms for on-line 3DGIS. Finally, the data security mechanism of on-line 3DGIS is presented. [ABSTRACT FROM AUTHOR]

SDP (Service Delivery Platform) is a recommended system platform for NGN (Next Generation Network) that is expected to resolve two common system running problems: one is functional aspects such as high availability and providing effective maintenance methods, the other is cost aspects such as simplifying development method of a service. However, SDP is still on the way to be standardized, and its architecture has two problems: the congestion of service requests and flexibility of enabler, a service component of SDP. This paper explains how to build a SDP by adopting Distributed Data Driven Architecture and how our system resolves the problems by evaluating the prototype. [ABSTRACT FROM AUTHOR]

Grid computing provides infrastructure for solving distributed problem by sharing, selection and aggregation of distributed resources at runtime depending on their availability, performance, cost and user΄s quality of service requirements. Utilization of this powerful technology is mainly conditioned by tricky management of different architectures and environments and by the difficulty to identify an efficient resource selection to map tasks into grid resources that dynamically vary their features. Resources selection needs of intelligence based automatic workflow generation to predict optimal run-time jobs allocation. In this paper we propose a dynamic job run-time scheduling system based on Java and fuzzy technology to manage Grid resources and minimize human interaction in scheduling grid jobs. [ABSTRACT FROM AUTHOR]

The paper offers an associative-neural-net method to optimize resource allocation between independent tasks in a multiprocessor system. In the case of a dual-core CPU the method allows the task to be fully solved in ]> operations. [ABSTRACT FROM AUTHOR]

Wireless ad hoc network can be modeled as a unit disk graph (UDG) in which there is an edge between two nodes if and only if their Euclidean distance is at most one unit. The size of UDG is in O(n2), where n is the number of network nodes. In the literature, the geometric spanners like Relative Neighborhood Graph (RNG), Gabriel Graph (GG), Delaunay Triangulation (Del), Planarized Localized Delaunay Triangulation (PLDel) and Yao Graph are proposed, which are sparse subgraphs of UDG. In this paper, we propose a hierarchy of geometric spanners called the kth order RNG (k-RNG), kth order GG (k-GG), kth order Del (k-Del), and kth order Yao (k-Yao) to reduce the spanning ratio and control topology, sparseness and connectivity. We have simulated these spanners and compared with the existing spanners. The simulation results show that the proposed spanners have better properties in terms of spanning ratio and connectivity by controlling topology and sparseness. [ABSTRACT FROM AUTHOR]

Data outsourcing or database as a service is a new paradigm for data management in which a third party service provider hosts a database as a service. The service provides data management for its customers and thus obviates the need for the service user to purchase expensive hardware and software, deal with software upgrades and hire professionals for administrative and maintenance tasks. Since using an external database service promises reliable data storage at a low cost it is very attractive for companies. Such a service would also provide universal access, through the Internet to private data stored at reliable and secure sites in cloud computing infrastructures. However, recent governmental legislations, competition among companies, and data thefts mandate companies to use secure and privacy preserving data management techniques. The data provider, therefore, needs to guarantee that the data is secure, be able to execute queries on the data, and the results of the queries must also be secure and not visible to the data provider. Current research has been focused only on how to index and query encrypted data. However, querying encrypted data is computationally very expensive. Providing an efficient trust mechanism to push both database service providers and clients to behave honestly has emerged as one of the most important problem before data outsourcing to become a viable paradigm. In this paper, we describe scalable privacy preserving algorithms for data outsourcing in cloud computing infrastructures. Instead of encryption, which is computationally expensive, we use distribution on multiple sites that are available in the cloud and information theoretically proven secret sharing algorithms as the basis for privacy preserving outsourcing. The technical contributions of this paper is the establishment and development of a framework for efficient fault-tolerant scalable and theoretically secure privacy preserving data outsourcing that supports a diversity of database operations executed on different types of data. [ABSTRACT FROM AUTHOR]

The goal of this paper is to discuss some of the solution verification and validation challenges in hemodynamic simulation. Today the objective of hemodynamics is to efficiently provide reliable patient specific simulation to optimize cardiovascular procedures such as, for example, heart valve replacement or abdominal aorta aneurysm stenting. Achieving this objective requires a clear understanding of (1) what model should be valid to start a simulation; this is model validation, (2) how much numerical error the simulation carries; this is solution verification. Image acquisition and inflow-outflow boundary conditions bring a third source of uncertainties. We will discuss some of these issues in this paper. We will argue finally that perhaps the ability to run systematically and quickly patient specific hemodynamic simulation to build large data bases might be the best way to provide statistically valid indicators for better clinical practice. [ABSTRACT FROM AUTHOR]

Collage is a declarative programming model and runtime expressly targeted at building and deploying cross-organizational software as compositions of web components. Collage is based on an RDF data model, data-driven execution model, and flexible support for cross-organizational composition of both application and UI components. In this paper we outline a uniform set of Collage language features addressing end-to-end application design, including business objects, but with particular focus on user interaction, and adaptation to current interaction platforms such as web browsers. [ABSTRACT FROM AUTHOR]

Large-scale distributed applications tend to become more and more complex and hard to develop, and execute. Approaches used when building such systems have to be revised, in order to decrease coupling within the code and increase productivity during the development process. Especially event-based programming applied to Web services should gain much attention. In this paper, we present an experimental publish/subscribe infrastructure, which introduces robust event-based mechanisms to be used with Web services-enabled applications. The concept of this solution is built upon the extensibility and configurability principles. We show that performance gap between traditional distributed event-based technologies and the Web also services-based approach is not necessarily as significant as most people tend to think. [ABSTRACT FROM AUTHOR]

Traditional perimeter security solutions cannot cope with the com-plexity of VoIP protocols at carrier-class performance. We implemented a large-scale, rule-based SIP-aware application-layer-firewall capable of detect-ing and mitigating SIP-based Denial-of-Service (DoS) attacks at the signaling and media levels. The detection algorithms, implemented in a highly distributed hardware solution leveraged to obtain filtering rates in the order of hundreds of transactions per second, suggest carrier class performance. Firewall performs SIP traffic filtering against spoofing attacks; and request, response and out-of-state floods. The functionality and performance of the DoS prevention schemes were validated using a distributed test-bed and a custom-built, automated testing and analysis tool that generated high-volume signaling and media traffic, and performed fine grained measurements of filtering rates and load-induced delays of the system under test. The test-tool included SIP-based attack vectors of spoofed traffic, as-well-as floods of requests, responses and out-of-state message sequences. This paper also presents experimental results. [ABSTRACT FROM AUTHOR]

This paper introduces the Repeated Rational Secret Sharing problem. We borrow the notion of rational secret sharing from Halpern and Teague[1], where players prefer to get the secret than not to get the secret and with lower preference, prefer that as few of the other players get the secret. We introduce the concept of repeated games in the rational secret sharing problem for the first time, which enables the possibility of a deterministic protocol for solving this problem. This is the first approach in this direction to the best of our knowledge. We extend the results for the mixed model (synchronous) where at most t players can be malicious. We also propose the first asynchronous protocol for rational secret sharing. [ABSTRACT FROM AUTHOR]

Large scientific applications are usually developed, tested and used by a group of geographically dispersed scientists. The problems associated with the remote development and data sharing could be tackled by using collaborative working environments. There are various tools and software to create collaborative working environments. Some software frameworks, currently available, use these tools and software to enable remote job submission and file transfer on top of existing grid infrastructures. However, for many large scientific applications, further efforts need to be put to prepare a framework which offers application-centric facilities. Unified Air Pollution Model (UNI-DEM), developed by Danish Environmental Research Institute, is an example of a large scientific application which is in a continuous development and experimenting process by different institutes in Europe. This paper intends to design a collaborative distributed computing environment for UNI-DEM in particular but the framework proposed may also fit to many large scientific applications as well. [ABSTRACT FROM AUTHOR]

Mobile computation enables computations to move between a dynamic set of locations and is becoming an increasingly important paradigm. Mobile Haskell (mHaskell) is an extension of Haskell that supports mobile computation in open distributed systems i.e. dynamically changing systems where multiple executing programs can interact using a predefined protocol. This paper outlines the mHaskell primitives, discusses the design and pragmatics of their implementation and includes preliminary performance comparisons with Jocaml. The implementation addresses several challenges, including serialisation of programs in a lazy language with sharing and using a combination of bytecode and machine code to manage the common software base, i.e. to determine what to communicate between locations. [ABSTRACT FROM AUTHOR]

The recent successes of a number of nonprofit computing projects distributed over the Internet has generated intense interest in the potential commercial applications of distributed computing. In a commercial setting, where participants might be paid for their contributions, it is crucial to define a security framework to address the threat of cheating and offer guarantees that the computation has been correctly executed. This paper defines and analyzes such a security framework predicated on the assumption that participants are motivated by financial gain. We propose a scheme which deters participants from claiming credit for work they have not done, and puts a high cost on attempts to disrupt the computation. We achieve these two goals by integrating an algorithm to assign computations to participants, an algorithm to verify their work, and an algorithm to pay participants. [ABSTRACT FROM AUTHOR]

High Performance Computing (HPC) is becoming much more popular nowadays. Currently, the biggest supercomputers in the world have hundreds of thousands of processors and consequently may have more software and hardware failures. HPC centers managers also have to deal with multiple clusters from different vendors with their particular architectures. However, since there are not enough HPC experts to manage all the new supercomputers, it is expected that non-experts will be managing those large clusters. In this paper we study the new challenges to manage HPC environments containing different clusters with different sizes and architectures. We review available tools and present LEMMing [1], an easy-to-use open source tool developed to support high performance computing centers. LEMMing integrates machine resources and the available management and monitoring tools on a single point of management. [ABSTRACT FROM AUTHOR]

In this paper, we present a global computer science approach to deal with parallel computations. The proposed approach consists in managing at the same level either multithreading or distributed strategies, whatever the computation may be. The integration of the concept is held in a Java framework which proposes both, a pure object-oriented paradigm and, convenient libraries to deal with threads management and communications schemes. The approach is illustrated on a domain decomposition method for a Navier-Stokes flow. [ABSTRACT FROM AUTHOR]

This paper describes a job distribution system which focuses on standard desktop worker nodes in inhomogeneous and unreliable environments. The system is suited for general purpose usage and supports both batch jobs and object-oriented interactive applications using standard Internet technologies. Advanced scheduling methods minimize the total execution time and improve execution efficiency, specialized to deal with unreliable failing worker nodes. [ABSTRACT FROM AUTHOR]

Since protein structure similarity searching is very complex and time-consuming, one of the possible acceleration methods is parallelization by distributing the calculation on multiple computers. In the paper, we present a theoretical model of the hierarchical multi-agent system dedicated to the task of protein structure similarity searching. We also show results of several numerical experiments confirming a suitability of such distribution for the similarity searching performed for the Muconate Lactonizing Enzyme (PDB ID = 1MUC) from the Protein Data Bank (PDB) against the database containing almost thousand randomly chosen molecules. [ABSTRACT FROM AUTHOR]

The aim has been to achieve the highest degree of possible concurrency in the execution of distributed program modules. To achieve this, a new invocation reordering algorithm is offered in this paper. The algorithm attempts to increase the time interval between each remote call instruction and the very first instructions using the values effected by the remote call. In order to increase the time distance, the algorithm reshuffles invocations, when possible, such that local invocations move in between remote calls and the instructions applying the results of the calls. The evaluation results indicate that the proposed algorithm provides higher degree of concurrency compared with the existing instruction reordering algorithms. [ABSTRACT FROM AUTHOR]

Replication provide an effective way to enhance performance, high availability and fault tolerance in distributed systems. There are numbers of fault tolerant and failure recovery techniques based on replication. These recovery techniques such as Netarkivet΄s data grid and fast disaster recovery mechanism for volume replication systems were implemented in two-replica distribution technique(TRDT) or primary-backup architecture. However, these techniques have its weaknesses as they inherit irrecoverable scenarios from TRDT such as double faults, both copies of a file are damaged or lost, missing of the content index in index server table and index server has generated checksum error in content index. In this paper we propose the failure recovery based on the Neighbor Replication Distribution technique (NRDT) to recover the irrecoverable scenarios and to improve the recovery performance. This technique considered neighbors have the replicated data, and thus, maximize the fault tolerant as well as reliability in failure recovery. Also, the technique outperform the TRDT in failure recovery by reducing the irrecoverable cases in TRDT. It also tolerates failures such as server failures, site failure or even network partitioning due to it has more the one back up or replica. [ABSTRACT FROM AUTHOR]

Multi-agent systems (MAS) paradigm emerged as an innovative technology that seemed to be applicable to a large number of distributed problems. However, during these years, ubiquitous computing and ambient intelligence among other distributed paradigms have proposed problems that are currently coped with other technologies. MAS have remained in research environments without establishing themselves in the distributed computing field, despite the benefits it could provide to it. In this paper, the key factors that have produced this situation are pointed, and solutions in order to fix it are proposed. APoDDS is a platform which collects all these solutions and merge them. Finally, a comparison between the new approach and the well-known agent platform JADE is made in order to evaluate the proposal. [ABSTRACT FROM AUTHOR]

Computation tasks used in digital design flow for test quality evaluation can require a lot of processor and memory resources. To speed up execution and to overcome memory restrictions, a collaborative computing approach was proposed in this paper. Web-based system architecture allows seamlessly aggregate many remote computers for one application. Efficient collaboration requires credit based priority concept, issues of task partitioning, task allocation, load balancing and model security must be handled. Experimental results show feasibility of proposed solution and gain in performance. [ABSTRACT FROM AUTHOR]

RFID technology that identifies objects on request of dynamic linking and tracking is composed of application components supporting information infrastructure. Despite their many advantages, existing applications, which do not consider elements related to real-time data communication among remote devices, cannot support connections among heterogeneous devices effectively. As different network devices are installed in applications separately and go through different query analysis processes, there happen the delays of monitoring or errors in data conversion. This paper proposes recommendation service that can update and reflect personalized profiles dynamically in Distributed Computing environment for integrated management of information extracted from RFID tags regardless of application. The advanced personalized module helps the service recommendation server make regular synchronization with the personalized profile. The proposed system can speed and easily extend the matching of services to user profiles and matching between user profiles or between services. Finally dynamic profiling help to reduce the development investment, improve the system΄s reliability, make progress in the standardization of real-time data processing in matching searching system. [ABSTRACT FROM AUTHOR]

The Reference Model for Open Distributed Processing (RM-ODP) defines a framework for the development of Open Distributed Processing (ODP) systems in terms of five viewpoints. Each viewpoint language defines concepts and rules for specifying ODP systems from the corresponding viewpoint. However the ODP viewpoint languages are abstract and do not show how these should be represented and specified. We treat in this paper the need of formal notation and specification for behavioural concepts in the enterprise language. Using the Unified Modelling Language (UML)/OCL (Object Constraints Language) we define a formal semantics for a fragment of ODP behaviour concepts defined in the RM-ODP foundations part and in the enterprise language. We mainly focus on time, action, behaviour constraints (sequentiality, non determinism and concurrency constraints), and policies (permission, obligation, prohibition). We also give a mapping of the considered concepts to Event-B. This will permit the verification of such specifications. [ABSTRACT FROM AUTHOR]

This paper describes the parallelization process of the code PROMES, which represents a regional atmospheric model developed by some of the authors. The parallel code, called PROMESPAR, has been carried out under a distributed platform (cluster of PCs) and using Message Passing Interface (MPI) communication subroutines. [ABSTRACT FROM AUTHOR]

Distributed systems can be very large and complex and the many different considerations which influence their design can result in a substantial body of specification, which needs a structuring framework if it is to be managed successfully. The purpose of the RM-ODP is to define such a framework. The Reference Model for Open Distributed Processing (RM-ODP) provides a framework within which support of distribution, inter-working and portability can be integrated. It defines: an object model, architectural concepts and architecture for the development of ODP systems in terms of five viewpoints. However, RM-ODP is a meta-norm, and several ODP standards have to be defined. Indeed, the viewpoint languages are abstract in sense that they define what concepts should be supported and not how these concepts should be represented using the UML/OCL meta-modeling approach. In this paper, we report on the definition and address of the syntax and semantics for a fragment of ODP object concepts defined in the RM-ODP foundations part and in the information language. These concepts are suitable for describing and constraining ODP information viewpoint specifications. [ABSTRACT FROM AUTHOR]

This paper describes specification and execution of behavioral concepts for Open Distributed Processing (ODP) Computational Language. Open Distributed Processing - ODP is introduced as a general framework upon which open distributed system can be modeled through the viewpoint concept and the use of an object oriented language (Unified Modeling Language UML). The behavior of an ODP system is determined by collecting all possible actions in which the system (acting as an object), or any of its constituent objects, might take part, together with a set of constraints on when these actions can occur. In order to specify the executable behavior of a system and to make the processes of the Computational executable and controllable, the Reference Model for ODP RM-ODP can be used as a meta-model for behavioral specifications. In the Computational language, the behavior is a collection of actions with a set of constraints on when they may occur. Firstly, we give the description and specification of the behavior by the activity diagrams. Secondly, we define the mapping from the concepts of behavior Computational language to BPEL concepts and we present the syntax and the structure of a BPEL Behavior process. Then we generate the corresponding BPEL and computational files to implement the specified process. [ABSTRACT FROM AUTHOR]

We focus in this paper on the specification and the execution of behavioral concepts for Open Distributed Processing (ODP) Enterprise Language. The behavior of an ODP system is determined by the collection of all the possible actions in which the system (acting as an object), or any of its constituent objects, might take part, together with a set of constraints on when these actions can occur. In order to specify the executable behavior of a system and to make the processes of the enterprise executable and controllable, the Reference Model for ODP RM-ODP can be used as a meta-model for behavioral specifications. In the enterprise language the behavior is specified in terms of roles, processes, policies, and the relationships between these concepts. Firstly, we give the description and specification of the behavior by the activity diagrams. Secondly, we define the mapping from the concepts of behavior enterprise language to BPEL concepts and we present the syntax and the structure of a BPEL Behavior process. Then we generate the corresponding BPEL and computational files to implement the specified process. [ABSTRACT FROM AUTHOR]

The Reference Model for Open Distributed Processing (RM-ODP) defines a framework within which support of distribution, interoperability and portability can be integrated. An ODP system is defined in terms of five viewpoints. The ODP engineering specification consists of a set of engineering objects which communicate via a channel object. The engineering viewpoint defines the ODP transparencies and ODP functions. We focus in this paper on the language of the channel engineering object. We associate to each component state of a global state a set of words that may be contained in channels. We define, for each object, a grammar 'like' context free in which, each rule is of the form X→ u-1Yv, where u-1Yv stand for the residual of the language (L(Y)v) with regard to u. We use context-free grammar properties to make transformations and appear a symbol X in the right member of each X-production to express loop and cycle transitions in the CFSM. The algebraic property of context-free languages is then used to calculate these languages which are minimal solution of a system of equations. These languages can be used to verify some protocol properties such as reachability and deadlock problems. [ABSTRACT FROM AUTHOR]

Context-aware systems are one of the most important application domains of pervasive computing. In this paper, a new context model is proposed, which is based on the composite sensor concept. Unlike simple ones (physical, virtual or logical sensors), a composite sensor is a logical sensor which is integrated from simple and/or other composite ones. Therefore, composite sensor has more semantic meaning than simple ones and can be used to describe complicated context domain objects, in a natural way that separates requirement from design. Based on composite sensor context model, we present a context modeling method, ComSensor, and a pervasive computing architecture, ComArch, which is suitable for different kinds of pervasive computing applications. The performance examining results of a simulation prototype system show that applications based upon ComArch can run in real-time mode. [ABSTRACT FROM AUTHOR]

Checkpointing schemes facilitate fault recovery in distributed systems. The present work extends James S Plank's Diskless checkpointing scheme (N+1 Parity) by introducing 'Timeout' to checkpoint programs with high locality of 1reference. This mechanism enables applications with high locality of reference to take checkpoints periodically. The limitation of N+1 Parity scheme is that all the processes freeze their respective computation, while taking synchronous checkpoints. The Enhanced N+1 Parity Scheme solves this problem by introducing a new message logging technique namely partial message logging which allows asynchronous checkpointing at both sender and receiver. This paper includes the performance evaluation of proposed scheme by making use of distributed simulator test-bed. The results indicate that proposed scheme outperforms N+1 Parity Scheme. [ABSTRACT FROM AUTHOR]

The Reference Model for Open Distributed Processing (RM-ODP) defines a framework for the development of Open Distributed Processing (ODP) systems in terms of five viewpoints. Each viewpoint language defines concepts and rules for specifying ODP systems from the corresponding viewpoint However the ODP viewpoint languages are abstract and do not show how these should be represented. We treat in this paper the need of formal notation for behavioral l concepts in the enterprise language. Using the Unified Modelling Language (UML)/OCL (Object Constraints Language) we define a formal semantics for a fragment of ODP behavior concepts defined in the RM-ODP foundations part and in the enterprise language. We mainly focus on time, action, sequentiality, non determinism, behavior constraints and permission, obligation and prohibition. [ABSTRACT FROM AUTHOR]

Handling very large volumes of confidential data is becoming a common practice in many organizations such as statistical agencies. This calls for the use of protection methods that have to be validated in terms of the quality they provide. With the use of Record Linkage (RL) it is possible to compute the disclosure risk, which gives a measure of the quality of a data protection method. However, the RL methods proposed in the literature are computationally costly, which poses difficulties when frequent RL processes have to be executed on large data. Here, we propose a distributed computing technique to improve the performance of a RL process. We show that our technique not only improves the computing time of a RL process significantly, but it is also scalable in a distributed environment. Also, we show that distributed computation can be complemented with SMP based parallelization in each node increasing the final speedup. [ABSTRACT FROM AUTHOR]

Stemming algorithms are commonly used in Information Retrieval with the goal of reducing the number of the words which are in the same morpho-logical variant in a common representation. Stemming analysis is one of the tasks of the pre-processing phase on text mining that consumes a lot of time. This study proposes a model of distributed stemming analysis on a grid environment to reduce the stemming processing time; this speeds up the text preparation. This model can be integrated into grid-based text mining tool, helping to improve the overall performance of the text mining process. [ABSTRACT FROM AUTHOR]

Partitioned global address space (PGAS) languages, such as Unified Parallel C (UPC) have the promise of being productive. Due to the shared address space view that they provide, they make distributing data and operating on ghost zones relatively easy. Meanwhile, they provide thread-data affinity that can enable locality exploitation. In this paper, we are considering sparse matrix multiplication which is an important operation for many scientific and engineering applications. Recently, several different high-performance algorithms and libraries have been developed for that operation. However, in this work, we were able to take advantage of one of the advanced features provided by UPC, which is the fact that it is a globally addressable memory model. Due to that feature, using UPC in this operation would enable threads to read or write data from any other thread's memory directly without any inter-process communication as the case with MPI. Our goal is to evaluate the performance of both parallel programming models based on experimental evaluation of sparse matrix multiplication. The comparative analysis will consider conceptual complexity and execution time. It will be shown that UPC which supports distributed shared memory model has a great productivity advantage over message passing when sparse matrix multiplication problems are considered. [ABSTRACT FROM AUTHOR]

Massively parallel distributed-memory architectures are receiving increasing attention to meet the increasing demand on processing power. Many topologies have been proposed for interconnecting the processors of distributed computing systems. The hypercube topology has drawn considerable attention due to many of its attractive properties. The appealing properties of the hypercube topology such as vertex and edge symmetry, recursive structure, logarithmic diameter, maximally fault-tolerance, simple routing and broadcasting, and the ability to simulate other interconnection networks with minimum overhead have made it an excellent candidate for many parallel processing applications. Many variations of the hypercube topology have been reported in the literature, mainly to add to the computational power of the hypercube. One of the attractive versions of the hypercube that was introduced to enhance the performance is the twisted hypercube. A twisted hypercube has the same structural complexities of the hypercube. It preserves the attractive properties of the hypercube and improves on the communication time by reducing the diameter by a factor of two. This paper presents the basic communication and some of the basic operations usually needed in parallel computing on the twisted hypercube interconnection network. [ABSTRACT FROM AUTHOR]

The task scheduling is one of the key technologies for grid services management. Although distributed systems and parallel networking systems have made a lot of research on resources scheduling, the traditional scheduling way can not adapt to the grid environment due to its heterogeneous and dynamic characteristics. Considering grid's characteristics, this paper explores the basic ant colony algorithm in depth and makes the improvements for it, at the same time, proposes a new algorithm, ACATS, for grid task scheduling. The tests' results show that ACATS is superior to all other heuristic methods for grid task scheduling. [ABSTRACT FROM AUTHOR]

In distributed computing environments, clients often need to dynamically download code archives containing program modules from different servers. The hierarchical inner structure of code archives and the partial overlapping between different versions of code archives imposes the applicability of semantic caching approaches, which basically aim at reducing the size of result sets of future queries by intersecting them with results that can already be anticipated from the cache content. This paper devises an extension for an existing cache infrastructure for code archives to adopt notions of semantic caching, allowing it to reason over the discrete contents of its cache store. The logical framework of the implementation is provided by a formal model. A preliminary performance evaluation proves the effectiveness and efficiency in terms of saved band-with and download times, especially for slow client-server connections. [ABSTRACT FROM AUTHOR]

The article discusses the development, architecture, and functionality of the National Partnership for Advanced Computational Infrastructure National Partnership for Advanced Computational Infrastructure (NPACI) Grid Portals project. The emphasis of this paper is on the NPACI Grid Portal Toolkit (GridPort). The software used to build Grid portals must interact with the middleware running on Grid resources, and in some cases it must provide missing functionality when the Grid middleware is not available for a specific resource or it is lacking capabilities needed by the Grid portal. The portal software must also be compatible with common Web servers and browsers.

Examines the issue of confidentiality of transmitted messages and of the devices themselves in ubiquitous computing. Analysis of asymmetric asymmetric cryptosystems; Comparison of maximum rate and maximum number of cycles; Distinction between secure disposal and encrypted storage.

Matrix multiplication is an integral component of most of the systems implementing Graph theory, Numerical algorithms, Digital control, Signal and image processing (i.e robotics, computer vision, artificial intelligence e.t.c). So reduction of multiplication time can influence drastically the overall system performance. Based on the importance, this paper presents a novel distributed algorithm for matrix multiplication to lower the time complexity efficiently. For distributed processing, computational time is usually analyzed assuming that all processors are of the same type and operating at same speed. i.e., homogeneous system. A number of autonomous machines are connected by a local area network that makes a distributed computing environment where server and multiple clients exchange their data or information by using message passing technique. The result shows that an enormous amount of time can be reduced by adopting such technique by dividing the tasks on different clients, where execution time grows rapidly with the increase of data on a single machine. [ABSTRACT FROM AUTHOR]

We present a framework that enables application developers to create complex and application specific network services. The essence of our approach is to utilize programmable network elements to create a software representation of network elements in the application. We show that the typical pattern of an application specific network service is a control loop in which topology, paths, and services are continuously monitored and adjusted to match application specific qualities. We present a platform in which network control applications can be developed and illustrate possible use cases. Based on these use cases, new research questions are identified. [ABSTRACT FROM AUTHOR]

Resource performance prediction is the basis of dynamic load balance in distributed computing. A model for resource performance prediction named ARPP is introduced and carried out. ARPP model monitors key parameters of resources and estimates the directions using ant algorithm. The implement and analysis of ARPP is based on GridSim simulator and the process of astronomical image mosaicking application. The experiment result shows the efficiency of the model and the determination of optimized parameters. [ABSTRACT FROM AUTHOR]

We propose an inherently three-dimensional interaction paradigm which allows individuals to manage their personal digital artifact collections (PAC) regardless of the specific devices and means they are using. The core of our solution is to provide unified access to all user artifacts normally spread across several repositories and devices. Not till then individuals may foster and evolve persistent multi-hierarchical artifact structures (PAS) fitting their cognitive needs. PAS subsets can be arranged and meaningfully related to virtual habitats or even mapped to physical contexts and environments they are frequenting to solve their tasks. [ABSTRACT FROM AUTHOR]

We present a framework for modelling and analyzing emerging neural activity from multiple interconnected modules, where each module is formed by a neural network. The neural network simulator operates a 2D lattice tissue of leaky integrate-and-fire neurons with genetic, ontogenetic and epigenetic features. The Java Agent DEvelopment (JADE) environment allows the implementation of an efficient automata-like virtually unbound and platform-independent system of agents exchanging hierarchically organized messages. This framework allowed us to develop linker agents capable to handle dynamic configurations characterized by the entrance and exit of additional modules at any time following simple rewiring rules. The development of a virtual electrode allows the recording of a ˵neural″ generated signal, called electrochipogram (EChG), characterized by dynamics close to biological local field potentials and electroencephalograms (EEG). These signals can be used to compute Evoked Potentials by complex sensory inputs and comparisons with neurophysiological signals of similar kind. [ABSTRACT FROM AUTHOR]

We consider a fixed, undirected, known network and a number of ˵mobile agents″ which can traverse the network in synchronized steps. Some nodes in the network may be faulty and the agents are to find the faults and repair them. The agents could be software agents, if the underlying network represents a computer network, or robots, if the underlying network represents some potentially hazardous physical terrain. Assuming that the first agent encountering a faulty node can immediately repair it, it is easy to see that the number of steps necessary and sufficient to complete this task is Θ(n/k + D), where n is the number of nodes in the network, D is the diameter of the network, and k is the number of agents. We consider the case where one agent can repair only one faulty node. After repairing the fault, the agent dies. We show that a simple deterministic algorithm for this problem terminates within O(n/k + Dlogf/loglogf) steps, where f =  min {n/k, n/D}, assuming that the number of faulty nodes is at most k/2. We also demonstrate the worst-case asymptotic optimality of this algorithm by showing a network such that for any deterministic algorithm, there is a placement of k/2 faults forcing the algorithm to work for Ώ(n/k + Dlogf/loglogf) steps. [ABSTRACT FROM AUTHOR]

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 logn) moves, where n is the number of nodes, even when the links are not FIFO. [ABSTRACT FROM AUTHOR]

Spectral clustering algorithm has been shown to be more effective in finding clusters than most traditional algorithms. However, spectral clustering suffers from a scalability problem in both memory use and computational time when a dataset size is large. To perform clustering on large datasets, we propose to parallelize both memory use and computation on distributed computers. Through an empirical study on a large document dataset of 193,844 data instances and a large photo dataset of 637,137, we demonstrate that our parallel algorithm can effectively alleviate the scalability problem. [ABSTRACT FROM AUTHOR]

Calculating reducts is a very important process. Unfortunately, the process of computing all reducts in NP-hard. There are a lot of heuristic solutions for computing reducts, but they do not guarantee achieving complete set of reducts. We propose here three versions of an exact algorithm, designed for parallel processing. We present here how to decompose the problem of calculating reducts, so that parallel calculations are efficient. [ABSTRACT FROM AUTHOR]

Examines the issue of authentication in ubiquitous computing. Impact of the absence of an online server; Analysis of secure transient association; Discussion of the resurrecting duckling security policy model.