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This paper proposes a diagnosis framework for distributed systems based on pomset languages. Diagnosis is performed by projecting these models on a collection of observable labels and then synchronization with an observation. This paper first proposes a new model called boxed pomset languages, which extends classical pomset-based languages as so called High-level Message Sequence Charts. It can describe infinite scenarios, and has good properties with respect to projections. We then give a solution for the event correlation problem (knowing whether two observed alarms are causally related) for pomset languages. [ABSTRACT FROM AUTHOR]

This paper describes a car traffic control simulation realised in a decentralised way by message propagations: congested nodes (roads intersections) send speed-up or slow-down messages to neighbouring nodes. Different types of journeys have been modelled: regular car journeys, accidents and emergency cars journeys. These journeys have different lengths and speeds, and affect the system differently. Optimal values of parameters, used during the simulations for controlling the cars, have been determined through the use of a genetic algorithm (GA). This paper reports as well a preliminary experiment on different simulations realised with parameters values derived from the GA. [ABSTRACT FROM AUTHOR]

This tool paper describes the functionality of ProM. Version 4.0 of ProM has been released at the end of 2006 and this version reflects recent achievements in process mining. Process mining techniques attempt to extract non-trivial and useful information from so-called "event logs". One element of process mining is control-flow discovery, i.e., automatically constructing a process model (e.g., a Petri net) describing the causal dependencies between activities. Control-flow discovery is an interesting and practically relevant challenge for Petri-net researchers and ProM provides an excellent platform for this. For example, the theory of regions, genetic algorithms, free-choice-net properties, etc. can be exploited to derive Petri nets based on example behavior. However, as we will show in this paper, the functionality of ProM 4.0 is not limited to control-flow discovery. ProM 4.0 also allows for the discovery of other perspectives (e.g., data and resources) and supports related techniques such as conformance checking, model extension, model transformation, verification, etc. This makes ProM a versatile tool for process analysis which is not restricted to model analysis but also includes log-based analysis. [ABSTRACT FROM AUTHOR]

Upward-closed sets of integer vectors enjoy the merit of having a finite number of minimal elements, which is behind the decidability of a number of Petri net related problems. In general, however, such a finite set of minimal elements may not be effectively computable. In this paper, we develop a unified strategy for computing the sizes of the minimal elements of certain upward-closed sets associated with Petri nets. Our approach can be regarded as a refinement of a previous work by Valk and Jantzen (in which a necessary and sufficient condition for effective computability of the set was given), in the sense that complexity bounds now become available provided that a bound can be placed on the size of a witness for a key query. The sizes of several upward-closed sets that arise in the theory of Petri nets as well as in backward-reachability analysis in automated verification are derived in this paper, improving upon previous decidability results shown in the literature. [ABSTRACT FROM AUTHOR]

Reconfigurable place/transition systems are Petri nets with initial markings and a set of rules which allow the modification of the net during runtime in order to adapt the net to new requirements of the environment. In this paper we use transformation rules for place/transition systems in the sense of the double pushout approach for graph transformation. The main problem in this context is to analyze under which conditions net transformations and token firing can be executed in arbitrary order. This problem is solved in the main theorems of this paper. Reconfigurable place/transition systems then are applied in a mobile network scenario. [ABSTRACT FROM AUTHOR]

In this paper, we consider bounded Time Petri Nets where time intervals (strict and large) are associated with places (P-TPN), arcs (A-TPN) or transitions (T-TPN). We give the formal strong and weak semantics of these models in terms of Timed Transition Systems. We compare the expressiveness of the six models w.r.t. (weak) timed bisimilarity (behavioral semantics). The main results of the paper are : (i) with strong semantics, A-TPN is strictly more expressive than P-TPN and T-TPN; (ii) with strong semantics P-TPN and T-TPN are incomparable ; (iii)T-TPN with strong semantics and T-TPN with weak semantics are incomparable. Moreover, we give a classification by a set of 9 relations explained in Fig. 14 (p. 80). [ABSTRACT FROM AUTHOR]

This paper describes the application of Real-Time Maude to the formal specification, simulation, and further formal analysis of the sophisticated state-of-the-art OGDC wireless sensor network algorithm. Wireless sensor networks in general, and the OGDC algorithm in particular, pose many challenges to their formal specification and analysis, including novel communication forms, treatment of geographic areas, time-dependent and probabilistic features, and the need to analyze both correctness and performance. Real-Time Maude extends the rewriting logic tool Maude to support formal specification and analysis of object-based real-time systems. This paper explains how we formally specified OGDC in Real-Time Maude, how we could simulate our specification to perform all the analyses done by the algorithm developers using the network simulation tool ns-2, and how we could perform further formal analyses which are beyond the capabilities of simulation tools. A remarkable result is that our Real-Time Maude simulations seem to provide a much more accurate estimate of the performance of OGDC than the ns-2 simulations. To the best of our knowledge, this is the first time a formal tool has been applied to an advanced wireless sensor network algorithm. [ABSTRACT FROM AUTHOR]

This paper presents a Connectivity based Partition Approach (CPA) to reduce the energy consumption of a sensor network by sleep scheduling among sensor nodes. CPA partitions sensors into groups such that a connected backbone network can be maintained by keeping only one arbitrary node from each group in active status while putting others to sleep. Nodes within each group swap between active and sleeping status occasionally to balance the energy consumption. Unlike previous approaches that partition nodes geographically, CPA is based on the measured connectivity between pairwise nodes and does not depend on nodes' locations. In this paper, we formulate node scheduling as a constrained optimal graph partition problem, and propose CPA as a distributed heuristic partition algorithm. CPA can ensure k-vertex connectivity of the backbone network for its partition so as to achieve the trade-off between saving energy and preserving network communication quality. Moreover, simulation results show that CPA outperforms other approaches in complex environments where the ideal radio propagation model does not hold. [ABSTRACT FROM AUTHOR]

In this paper, we consider how to localize individual nodes in a wireless sensor network when some subset of the network nodes can be in motion at any given time. For situations in which it is not practical or cost-efficient to use GPS or anchor nodes, this paper proposes an Anchor-Free Mobile Geographic Distributed Localization (MGDL) algorithm for wireless sensor networks. Taking advantage of the accelerometers that are present in standard motes, MGDL estimates the distance moved by each node. If this distance is beyond a threshold, then this node will trigger a series of mobile localization procedures to recalculate and update its location in the node itself. Such procedures will be stopped when the node stops moving. Data collected using Tmote Invent nodes (Moteiv Inc.) and simulations show that the proposed detection method can efficiently detect the movement, and that the localization is accurate and the communication is efficient in different static and mobile contexts. [ABSTRACT FROM AUTHOR]

Sensor networks are often used to sense the physical world and provide observations for various uses. In hostile environments, it is critical to control the network access to ensure the integrity, availability, and at times confidentiality of the sensor data. This paper develops efficient methods for distributed access control in sensor networks. The paper starts with a baseline approach, which provides a more flexible and efficient way to enforce access control when compared with previous solutions. This paper then extends the baseline approach to enable privilege delegation, which allows a user to delegate its privilege to other users without using a trusted server, and broadcast query, which allows a user to access the network at a large scale efficiently. The privilege delegation and broadcast query are very useful in practice; none of the current solutions can achieve these two properties. [ABSTRACT FROM AUTHOR]

In this paper we propose a framework for modeling mobile information systems. Mobility introduces several challenges and issues that impact the development of mobile systems. As a result, we want applications running on mobile devices to exhibit certain traits; they should be aware of the mobility and be adaptive to the changes that occur due to it. Literature has identified several types of mobility - among them, physical and logical mobility. The former pertains to tangible mobile entities like cars, devices and people, while the latter encompasses mobile software entities. In addition to these, this paper includes the concept of vertical mobility - the movement of a network connection between overlapping networks - in a UML profile for modeling mobile information systems. We discuss our experiences from a case study described in [1] , where we modeled a simple mobile information system and transformed parts of the model into code. [ABSTRACT FROM AUTHOR]

Ubiquitous computing environments are characterised by a high number of heterogeneous devices that generate a huge amount of context data. These data are used to adapt applications to changing execution contexts. However, legacy frameworks fail to process context information in a scalable and efficient manner. In this paper, we propose to organise the classical functionalities of a context manager to introduce a 3-steps cycle of data collection, interpretation, and situation identification. We propose the COSMOS framework, which is based on the concepts of context node and context management policies translated into software components in software architecture. This paper presents COSMOS and evaluates its efficiency throughout the example of the composition of context information to implement a caching/off-loading adaptation situation. [ABSTRACT FROM AUTHOR]

Migration of running application code is considered a very attractive and desired mechanism to improve application performance, resource sharing, self-adaptability, etc. This mechanism seems to be even more important nowadays, considering the growing interest in the area of mobile computing and mobile networks. This paper briefly presents a migration mechanism for a CORBA Component Model platform. We discuss general issues related to migration of running code, further elaborated in the context of CCM. We also propose an extension to the original CCM model which provides interfaces to implement migration. The paper presents the most important problems which appeared during implementation of a prototype facility and it discusses possible solutions. One of the most fundamental issues related to mobility of running code is the residual dependency problem. The intention of the work is not to provide a solution to this (possibly unsolvable) problem, but to propose an approach which would make programmers aware of its existence. Thus, the paper allows readers to make more conscious decisions when designing their components. The paper ends with an evaluation of the prototype implementation on top of OpenCCM, an open source Java implementation of the CORBA Component Model. [ABSTRACT FROM AUTHOR]

This paper presents an edge detection method based on bilateral filtering taking into account both spatial closeness and intensity similarity of pixels in order to preserve important visual cues provided by edges and reduce the sharpness of transitions in intensity values as well. In addition, the edge detection method proposed in this paper is achieved on sampled images represented on a newly developed virtual hexagonal structure. Due to the compact and circular nature of the hexagonal lattice, a better quality edge map is obtained. We also present a parallel implementation for edge detection on the virtual hexagonal structure that significantly increases the computation speed. [ABSTRACT FROM AUTHOR]

In recent large scale deployment of active RFID systems has been introduced by many applications, but a variety of critical issues remain unresolved. Especially, the impact of collision is the most essential problem. In this paper, we propose a Learning-based Dynamic Framed Slotted ALOHA algorithm (LDFSA) which mitigates collision from the active RFID tags and complies with international standard, ISO/IEC 18000-7. In addition, this paper includes the performance evaluations of the proposed LDFSA algorithm with the conventional algorithms. According to the result, the proposed LDFSA algorithm shows better performance than other conventional algorithms. [ABSTRACT FROM AUTHOR]

As grid infrastructures become more dynamic in order to cope with the uncertainty of demand, they are becoming extremely difficult to manage. At the Belfast e-Science Centre, we are attempting to address this issue by developing Self Managing Grid Middleware. This paper gives an overview of the middleware and focuses on the design, implementation and evaluation of a Resource Manager. Also in this paper we will see how our approach, which is based on federated UDDI registries, has enabled us to implement some of the desired features of next generation grid software. [ABSTRACT FROM AUTHOR]

The trustworthiness between anonymous web service client and provider influences service stability and collaboration. Trustworthiness includes some aspects such as service's security, controllability and survivability. So, a definition of trustworthiness for web service is given in the paper, and then a web service trustworthiness evaluation and management model is brought forth inspired by human small-world network. The model consists of three web service federations: WSRRC, APAEAS and AWSORT. WSRRC is a Web Service Resource Register Center, which is established by UDDI protocol. APAEAS is an Area Proxy Authentication Evaluating Autonomy System, which collects some authentication information of web service clients, accepts clients' special requirement and feedbacks service's trustworthiness values to AWSORT. AWSORT is an Area WS Resource Organizing Tree, which organizes and manages web service resources; records web service trustworthiness values, keeps web service state, assigning web service. The model establishes a trustworthy environment for anonymous web service clients and providers. Furthermore, some detailed evaluating parameters about service trustworthiness and quality is discussed and some service management algorithms are proposed in the paper. The simulation results show that model is feasible for semantic grid integration and establishment for virtual organization. [ABSTRACT FROM AUTHOR]

We present in this paper the recent developments done in P2P-MPI, a grid middleware, concerning the fault management, which covers fault-tolerance for applications and fault detection. P2P-MPI provides a transparent fault tolerance facility based on replication of computations. Applications are monitored by a distributed set of external modules called failure detectors. The contribution of this paper is the analysis of the advantages and drawbacks of such detectors for a real implementation, and its integration in P2P-MPI. We pay especially attention to the reliability of the failure detection service and to the failure detection speed. We propose a variant of the binary round-robin protocol, which is more reliable than the application execution in any case. Experiments on applications of up to 256 processes, carried out on Grid'5000 show that the real detection times closely match the predictions. [ABSTRACT FROM AUTHOR]

In the last years several Grid Virtual Organizations -VOs- have been proliferating, each one usually installing its own Certification Authority and thus giving birth to a large set of different and possibly untrusted security domains. Nevertheless, despite the fact that the adoption of Grid Certification Authorities (CAs) has partially solved the problem of identification and authentication between the involved parties, and that Public Key Infrastructure (PKI) technologies are mature enough, we cannot make the same assumptions when untrusted domains are involved. In this paper we propose an architecture to face the problem of secure interoperability among untrusted Grid-domains. Our approach is based on building a dynamic federation of CAs, formed thorough the quantitative and automatic evaluation of their Certificate Policies. In this paper we describe the proposed architecture and its integration into Globus Toolkit 4. [ABSTRACT FROM AUTHOR]

This paper discusses a study on system nervousness in a multi-agent manufacturing control system. Manufacturing control systems, built along this approach, are able to generate short-term forecasts that predict both resource loads and order routings. These forecasts become known throughout the multi-agent system with some time delay. If the agents make their decisions based on these forecasts, proper measures need to be taken to account for these delays, especially when disturbances (rush orders, machine breakdowns) occur. If agents react too eagerly and swiftly, the forecasts become unreliable. This paper studies this issue and the measures in the control system design that address the problem. More precisely, the agents behave in a socially acceptable manner that reconciles adaptation to changed circumstances with predictability. [ABSTRACT FROM AUTHOR]

Constraint Programming research is currently aimed at solving problems in a dynamically changing environment. This paper addresses the problem of solving a Dynamic Distributed Constraint Satisfaction Problem (Dynamic DCSP). The solution proposed is an algorithm implemented in a multi- agent system. A Dynamic DCSP is a problem in which variables, values and constraints are distributed among various agents. Agents can be freely added to or removed from the system. Most advanced applications cannot be represented by DCSPs, but they can be modeled by Dynamic DCSPs. The algorithm described in this paper is an extension of the Asynchronous Weak Commitment Search algorithm (AWCS) originally proposed by Yukoo [10]. The extended algorithm is designed to cope with the dynamically changing parameters of a Dynamic DCSP. The proposed algorithm differs from other Dynamic DCSP algorithms because it allows an unlimited number of changes to any of the variables, values, or constraints. This paper describes an agent system implementing the modified AWCS algorithm and verifies its effectiveness by applying it to a dynamic N-Queens problem. The results prove the applicability of the modified algorithm to Dynamic DCSP. [ABSTRACT FROM AUTHOR]

This paper introduces systems of exchange values as tools for the self-regulation of multi-agent systems. Systems of exchange values are defined on the basis of the model of social exchanges proposed by J. Piaget. A model of social control is proposed, where exchange values are used for supporting the regulation of the performance of social exchanges. Social control is structured around two coordinated functions: the evaluation of the current balance of exchange values and the determination of the target equilibrium point for such balance, and the maintenance of the balance of exchange values around the current target equilibrium point. The paper focuses on the second function of social control, introducing a (for the moment, centralized) equilibrium supervisor that solves the problem of keeping the system in a state of equilibrium by making use of a Qualitative Markov Decision Process that uses intervals for the representation of exchange values. [ABSTRACT FROM AUTHOR]

Cooperation is a means for multi-agent systems to function more efficiently and more adaptively. Cooperation can be viewed as a local criterion for agents to self-organize and then to perform a more adequate collective function. This paper mainly aims at showing that with only local rules based on cooperative attitude and without any global knowledge, a solution is provided by the system and local changes lead to global reorganization. This paper shows an application of cooperative behaviors to a dynamic distributed timetabling problem, ETTO, in which the constraint satisfaction is distributed among cooperative agents. This application has been prototyped and shows positive results on adaptation, robustness and efficiency of this approach. [ABSTRACT FROM AUTHOR]

The paper starts with a description of the fundamental principles of modern Digital Rights Management Systems. This is the basis for the discussion of their most important security aspects from the provider's view on the one hand and the customer's view on the other hand. The second half of the paper focuses the new DRM standard from the Open Mobile Alliance (OMA) and its implementation on "open" systems like Windows. The security anchor of the OMA DRM is the device private key. As long as no trusted storage facilities for open systems work effectively, techniques for software obfuscation could be a solution. Therefore the obfuscation of the device private key and its secure download is described. Currently on Windows PCs there is no chance for a full tamper-proof solution, but the authors try to make the job of an attacker as hard as possible, without affecting the consumer's security. [ABSTRACT FROM AUTHOR]

Privacy-preserving decision tree mining is an important problem that has yet to be thoroughly understood. In fact, the privacy-preserving decision tree mining method explored in the pioneer paper [1] was recently showed to be completely broken, because its data perturbation technique is fundamentally flawed [2]. However, since the general framework presented in [1] has some nice and useful features in practice, it is natural to ask if it is possible to rescue the framework by, say, utilizing a different data perturbation technique. In this paper, we answer this question affirmatively by presenting such a data perturbation technique based on random substitutions. We show that the resulting privacy-preserving decision tree mining method is immune to attacks (including the one introduced in [2]) that are seemingly relevant. Systematic experiments show that it is also effective. Keywords: Privacy-preservation, decision tree, data mining, perturbation, matrix. [ABSTRACT FROM AUTHOR]

Recommender systems are widely used to help deal with the problem of information overload. However, recommenders raise serious privacy and security issues. The personal information collected by recommenders raises the risk of unwanted exposure of that information. Also, malicious users can bias or sabotage the recommendations that are provided to other users. This paper raises important research questions in three topics relating to exposure and bias in recommender systems: the value and risks of the preference information shared with a recommender, the effectiveness of shilling attacks designed to bias a recommender, and the issues involved in distributed or peer-to-peer recommenders. The goal of the paper is to bring these questions to the attention of the information and communication security community, to invite their expertise in addressing them. [ABSTRACT FROM AUTHOR]

In this paper, we study the fundamental limits of a wireless sensor network's lifetime under connectivity and k-coverage constraints. We consider a wireless sensor network with n sensors deployed independently and uniformly in a square field of unit area. Each sensor is active with probability p, independently from others, and each active sensor can sense a disc area with radius rs. Moreover, considering the inherent irregularity of a sensor's sensing range caused by time-varying environments, we model the sensing radius rs as a random variable with mean r0 and variance r02σs2. Two active sensors can communicate with each other if and only if the distance between them is smaller than or equal to the communication radius rc. The key contributions of this paper are: (1) we introduce a new definition of a wireless sensor network's lifetime from a novel probabilistic perspective, called ω-lifetime (0 ≤ ω ≤ 1). It is defined as the expectation of the time interval during which the probability of guaranteeing connectivity and k-coverage simultaneously is at least ω; and (2) based on the analysis results, we propose a near-optimal scheduling algorithm, called PIS (Pre-planned Independent Sleeping), to achieve the network's maximum ω-lifetime, which is validated by simulation results, and present a possible implementation of the PIS scheme in the distributed manner. [ABSTRACT FROM AUTHOR]

State-of-the-art dynamic middleware uses information about the environment in order to evaluate alternative configurations of an application and select one according to some criteria. In the context of applications sensitive to Quality of Service, we have identified the need for a platform independent description of configurations that includes non-functional behaviour, and that allows handling of a large number of application configurations. In this paper, we present a modelling principle and a service plan concept, which together represents such a description. The modelling principle and plan concept extend state-of-the-art with i) a model of the alternative configurations that ensure a minimum of reconfiguration steps; ii) a specification that contains information elements of the configuration, dependencies to the environment, and QoS characteristics; and iii) a platform independent specification. In the paper, we also perform a qualitative assessment of our approach, and we describe a proof-of-concept implementation. [ABSTRACT FROM AUTHOR]

This paper addresses a problem of integrating the consistency management of session guarantees with recovery mechanisms in distributed mobile systems. To solve such a problem, rollback-recovery protocol rVsSG, preserving session guarantees is proposed. The protocol employs known rollback-recovery techniques, however, while applying them, the semantics of session guarantees is taken into account. Consequently, rVsSG protocol is optimized with respect to session guarantees requirements. The paper includes the proof of safety property of the presented protocol. Keywords: fault tolerance, rollback-recovery, mobile systems, session guarantees. [ABSTRACT FROM AUTHOR]

Today many interactions are carried out online through Web sites and e-services and often private and/or sensitive information is required by service providers. A growing concern related to this widespread diffusion of on-line applications that collect personal information is that users' privacy is often poorly managed and sometimes abused. For instance, it is well known how personal information is often disclosed to third parties without the consent of legitimate data owners or that there are professional services specialized on gathering and correlating data from heterogeneous repositories, which permit to build user profiles and possibly to disclose sensitive information not voluntarily released by their owners. For these reasons, it has gained great importance to design systems able to fully preserve information privacy by managing in a trustworthy and responsible way all identity and profile information. In this paper, we investigate some problems concerning identity management for e-services and present the architecture of the Access Control Decision Function, a software component in charge of managing access request in a privacy-aware fashion. The content of this paper is a result of our ongoing activity in the framework of the PRIME project (Privacy and Identity Management for Europe) [18], funded by the European Commission, whose objective is the development of privacy-aware solutions for enforcing security. [ABSTRACT FROM AUTHOR]

Escalating energy costs and the overloaded power plants during peak demand periods are major concerns many industrialized nations have to deal with today. This paper discusses the deployment of an Intelligent Dynamic Local Area Power Dispatch System (DLAPDS) utilizing Radio Frequency (RF) and local Area Network (LAN) technologies. In this paper, the authors will further discuss on ways to incorporate Artificial Intelligence (AI) ideologies in building a LAPDS that is both more efficient in energy deployment and saving. [ABSTRACT FROM AUTHOR]

In order to capture and relate different aspects of a problem domain, we often require different languages or models. A metamodeling approach can be used to define these languages and models in a rich semantic way. However, current tools or frameworks cannot satisfy the multilayer metamodeling requirement. We suggests a reusable MOF (Meta-Object Facility) metamodeling framework through the Down-up mechanism between the meta-layer model and model-layer model, and this mechanism supports multilayer metamodeling and is compatible with MOF. This paper also suggests a MOF's Bootstrap model by which the framework constructs models in a unified way. In addition, this paper gives a model shift synchronization pruning algorithm in order to keep the relationship consistent between the meta-layer model and the model-level model. As an example, we use the framework to model an agent-based workflow system, and this practice proves the framework can satisfy multilayer modeling requirements in different aspects of a problem domain. [ABSTRACT FROM AUTHOR]

Nowadays business process management (BPM) receives more and more attention and is considered as the "next step" after the workflow wave of the 1990s. Due to the complexity and divergence of business processes, many challenges need to be solved when developing a business process management system (BPMS). In this paper, a system based on Cova, a meta-groupware, is proposed to support business processes. The paper shows how the functionality of Cova is extended with the new emerging Web technologies and how unstructured collaboration is supported via instant messaging, conference service and agent technology. The proposed approach can be used as a reference when improving existing systems or developing new solutions to support business processes. [ABSTRACT FROM AUTHOR]

The goal of virtual prototyping is to decrease the time and costs in product development and to increase quality and flexibility by providing continuous computer support for the development cycle. This paper investigates and summarizes the existing efforts on collaborative virtual prototyping and digit product modeling. To overcome the weaknesses in the existing work, this study introduces a theory of directed acyclic graph (DAG) and gives definitions to the related concepts, and then provides a modeling method of virtual prototyping based on DAG. In particular, the concepts about this method, such as scene, entity, scene graph, linear scene graph, nonlinear scene graph, are explicitly defined. Following these definitions, the principle and method with regards to building the virtual prototyping for collaborative design are explained through an example. In the end, the paper concludes with the features of the modeling method of virtual prototyping based on DAG. This method benefits that 3D objects from different applications can be joined into one shared scene that can be viewed, manipulated in independent or shared camera positions by different users, thus facilitating collaborative virtual prototyping for remote distributed design. [ABSTRACT FROM AUTHOR]

Effective editing tools are very important to innovative design of 3D object. The technologies for designing tools presented in this paper mainly involve collaborative mechanism and natural interaction for collaborative editing environment. For collaborative mechanism, three aspects are covered in this paper: one aspect is 3D object attributes analysis which is essential to the conflict solution of collaborative design process. Interaction transaction log of 3D collaborative editing environment and the system architecture are put forward and addressed as another two aspects. Furthermore, based on interactive transaction log, the collaborative editing mechanism is constructed and the conflict detection strategy during multi-user concurrency editing process is also discussed. As for interaction naturalness, the pen-based gestures appropriate to manipulating 3D model are covered briefly. Finally a prototype system has been built to fully explore the above technologies. [ABSTRACT FROM AUTHOR]

Recently, advanced information technologies have opened new possibilities for collaborative designs. In this paper, a Web-based collaborative design environment is proposed, where heterogeneous design applications can be integrated with a common interface, managed dynamically for publishing and searching, and communicated with each other for integrated multi-objective design. The CORBA (Common Object Request Broker Architecture) is employed as an implementation tool to enable integration and communication of design application programs; and the XML (eXtensible Markup Language) is used as a common data descriptive language for data exchange between heterogeneous applications and for resource description and recording. This paper also introduces the implementation of the system and the encapsulating issues of existing legacy applications. At last, an example of gear design based on the system is illustrated to identify the methods and procedures developed by this research. [ABSTRACT FROM AUTHOR]

Collaborative design and manufacturing through the Internet is becoming more necessary as enterprises are distributing their activities throughout the world. The approach presented in this paper deals with techniques that can support multi distributed clients and provide a dynamic database service, making possible a dynamic distributed design and manufacturing process, focusing on the product and process knowledge management from the whole value chain. The core application of the system presented in this paper manages the distributed design and manufacturing process through the internet among different teams. [ABSTRACT FROM AUTHOR]

In the competitive world of the 21 century, companies must improve the way they develop new products. With new technologies continuously emerging, it becomes more and more important for manufacturing enterprises to evaluate and choose appropriate technologies for specific situations and to keep the balance between the advantages of technologies and the feasibility of implementation. This paper proposes an Internet-based solution to facilitate Collaborative Product Development (CPD) in manufacturing enterprises. In the proposed system architecture, an Internet-based collaboration platform provides all participants with basic facilities, including collaboration services and database services. In the middle layer of the architecture, RCM-based (Result-Chain based Modelling) process management module, product structure management module, visualization module, and multimedia conference module work together to support collaboration between participant and no-participant users. Implementation technologies and future work are discussed in the paper. [ABSTRACT FROM AUTHOR]

Recently, many researchers have been concentrating on the development of cooperative CAPP systems. How to realize cooperative planning among heterogeneous CAPP systems in a networked manufacturing environment is a challenging issue. In this paper we adopt screen-sharing technology to solve this problem. We first propose an idea for cooperative process planning. Then we discuss potential solutions to the problems of screen-sharing technology, including cooperative control command management and shared data processing. An example of the networked manufacturing oriented cooperative CAPP system is briefly introduced at the end of this paper. [ABSTRACT FROM AUTHOR]

Complex modern artifacts are often designed collaboratively by both human and machine agents with different areas of expertise in a multi-agent system (MAS) environment. The interaction of such agents inevitably invokes exceptions, which are not well-addressed due to their sophistication. This paper focuses on conflicts, the primary presentation of exceptions among agents, and considers mainly conflict resolution (CR) in a knowledge-based system consisting of both machine-based and human designer agents. Based on previous studies, we propose a generic taxonomy of conflicts, a preliminary integrated conflict management mechanism, and a general CR scheme. A new system architecture is also presented in the paper, with the discussion of a case study. [ABSTRACT FROM AUTHOR]

The development of collaborative design raises new demands for information sharing and process integration among collaborating groups. Based on the analysis of these demands, this paper introduces an integration framework based on Semantic Web services. A task-oriented semantic representation model is built in the framework. This paper also discusses the handling processes of service requests for application tasks. The framework can improve the flexibility and maintainability of integration of collaborating systems and provide support for dynamic alliance oriented integrated product development. [ABSTRACT FROM AUTHOR]

The Session Initiation Protocol (SIP) provides powerful and flexible signaling capabilities for building video conferencing services. Traditionally, for SIP-based centralized video conference systems, the conferencing scale is mainly limited by both the capability of conference server and the availability of bandwidth. In this paper, our design focuses on how to provide dynamic scalability for the SIP-based video conferencing system when the number of conference users increases continually. Based on the study of the SIP protocol and the existing video conferencing models, we propose a dynamic scalable service model that can support to dynamically increase the number of conference servers without negative influence on the stability of system. This enables the extra service requests to be transferred and served in the cooperated conference servers. The paper also addresses the SIP-enabled conferencing flows based on the model in detail. We developed a prototype of video conference system based on the proposed model. Experimental results demonstrate the validity of this service model. [ABSTRACT FROM AUTHOR]

This paper presents recent research into the functions and value of sketch outputs during computer supported collaborative design. Sketches made primarily exploiting whiteboard technology are shown to support subjects engaged in remote collaborative design, particularly when constructed in ‘nearsynchronous' communication. The authors define near-synchronous communication and speculate that it is compatible with the reflective and iterative nature of design activity. There appears to be significant similarities between the making of sketches in near-synchronous remote collaborative design and those made on paper in more traditional face-to-face settings With the current increase in the use of computer supported collaborative working (CSCW) in undergraduate and postgraduate design education it is proposed that sketches and sketching can make important contributions to design learning in this context. [ABSTRACT FROM AUTHOR]

In a large-scale computer-supported cooperative design (CSCD) system, sometimes thousands of involved participants cooperate to design a complex product, which makes the network for the joint effort extremely complicated. It is difficult to detect and resolve conflicts because of strong and complicated conflicts among participants in this system. The traditional conflict resolution methodology which has been applied in a relatively small-scale cooperative system is inapplicable in a large-scale one. A conflict resolution methodology in a large-scale computer-supported cooperative design system is presented in this paper. The main contributions of this paper are: (1) simplifying the conflict model of a large-scale computer-supported cooperative design system in accordance with complex system theories; (2) presenting a merging conflict strategy model based on the complex system theories; (3) showing the role assignment mechanism in the merging conflict strategy system based on complex system theories. [ABSTRACT FROM AUTHOR]

Wireless Sensor Networks (WSN) are designed for data gathering and processing, with particular requirements and constraints: low hardware complexity, low energy consumption, special traffic pattern support, scalability, and in some cases, real-time operation. In this paper we present the Virtual TDMA for Sensors (VTS) MAC protocol, which intends to support the previous features, focusing particularly on real-time operation. VTS adaptively creates a TDMA arrangement with a number of timeslots equal to the actual number of nodes in range. Thus, VTS achieves an optimal throughput performance compared to TDMA protocols with fixed size of frame. The TDMA frame is set up and maintained by a distributed procedure, which allows sensors to asynchronously join and leave the frame. A major advantage of VTS is that it guarantees a bounded latency, which allows soft real-time applications. An expression for the upper latency bound is also provided in this paper. VTS performance is evaluated by simulation. Results show less power consumption than other proposals in the field. We also introduce a novel multi-hop operation by coordinated sleep/awake cycles among clusters. [ABSTRACT FROM AUTHOR]

In this paper, we propose and analyze an application called SOMA (SynchrOnous Multicast Application) which offers multicast file transfer service in an asymmetric intra-campus environment. For efficient bandwidth utilization, SOMA uses IP multicasting. Since TCP cannot be used in multicast situations, we also propose a transport protocol involving a flow control algorithm. This algorithm adapts the protocol window size and the overall application transfer rate to the minimum network capacity, allowing synchronism and reacting quickly when congestion arises at any router. The protocol behavior has been intensively tested in a lab, using a mixture of wired and wireless networks. The paper also explains how to capture and post-process SOMA network traffic. In addition, we develop a mathematical model to validate the most important protocol parameters. The methodology employed to define, analyze and evaluate this protocol is, indeed, another contribution and can be easily extended to other multicast protocols. [ABSTRACT FROM AUTHOR]

In this paper, we present a button-sized (43mm×18mm) visual input system for wearable computers, the FingerMouse. It is a fully integrated camera and vision processing system, with a specifically designed ASIC computing images at 20GOp/s consuming 78mW. Worn on the body, it captures the user's hand and processes in real-time its coordinates as well as a 1-bit image of the hand segmented from the background. This paper describes the architecture of the FingerMouse and compares it to other implementations. [ABSTRACT FROM AUTHOR]

The recent spectacular progress in modern microelectronics that enabled implementation of a complete complex system on a single chip created new important opportunities, but also new serious difficulties. This paper briefly analyses the situation, trends and problems in the field of the modern microelectronic-based systems. However, the main aim of the paper is to discuss the paradigms of life-inspired systems and quality-driven design that seem to be adequate to overcome the difficulties, and consider their application to the architecture synthesis for complex real-time embedded systems. [ABSTRACT FROM AUTHOR]

Emerging component-based software development architectures promise better re-use of software components, greater flexibility, scalability and higher quality of services. But like any other piece of software too, software components are hardly perfect, when being created. Problems and bugs have to be fixed and new features need to be added. This paper will give an introduction to the problem of component evolution and the syntactical incompatibilities which result during necessary multi component upgrades. The authors present an approach for the detection of such incompatibilities between multiple generations of component revisions basing on a formal interface model. The main concern of the paper will be the automated reconfiguration of component based software systems by intelligent swapping of component revisions to find conflict free system states. [ABSTRACT FROM AUTHOR]

Component adaptation needs to be taken into account when developing trustworthy systems, where the properties of component assemblies have to be reliably obtained from the properties of its constituent components. Thus, a more systematic approach to component adaptation is required when building trustworthy systems. In this paper, we illustrate how (design and architectural) patterns can be used to achieve component adaptation and thus serve as the basis for such an approach. The paper proposes an adaptation model which is built upon a classification of component mismatches, and identifies a number of patterns to be used for eliminating them. We conclude by outlining an engineering approach to component adaptation that relies on the use of patterns and provides additional support for the development of trustworthy component-based systems. [ABSTRACT FROM AUTHOR]