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Showing papers on "Shared resource published in 2005"


Journal ArticleDOI
TL;DR: This work proposes a gossip-based protocol for computing aggregate values over network components in a fully decentralized fashion and demonstrates the efficiency and robustness of the protocol both theoretically and experimentally under a variety of scenarios including node and communication failures.
Abstract: As computer networks increase in size, become more heterogeneous and span greater geographic distances, applications must be designed to cope with the very large scale, poor reliability, and often, with the extreme dynamism of the underlying network. Aggregation is a key functional building block for such applications: it refers to a set of functions that provide components of a distributed system access to global information including network size, average load, average uptime, location and description of hotspots, and so on. Local access to global information is often very useful, if not indispensable for building applications that are robust and adaptive. For example, in an industrial control application, some aggregate value reaching a threshold may trigger the execution of certain actions; a distributed storage system will want to know the total available free space; load-balancing protocols may benefit from knowing the target average load so as to minimize the load they transfer. We propose a gossip-based protocol for computing aggregate values over network components in a fully decentralized fashion. The class of aggregate functions we can compute is very broad and includes many useful special cases such as counting, averages, sums, products, and extremal values. The protocol is suitable for extremely large and highly dynamic systems due to its proactive structure---all nodes receive the aggregate value continuously, thus being able to track any changes in the system. The protocol is also extremely lightweight, making it suitable for many distributed applications including peer-to-peer and grid computing systems. We demonstrate the efficiency and robustness of our gossip-based protocol both theoretically and experimentally under a variety of scenarios including node and communication failures.

782 citations


Patent
24 Mar 2005
TL;DR: The Shared Internet Storage Resource (SISR) as mentioned in this paper provides Internet-based file storage, retrieval, access, control, and manipulation for a user by providing an easy-to-use user interface.
Abstract: The Shared Internet Storage Resource provides Internet-based file storage, retrieval, access, control, and manipulation for a user. Additionally, an easy-to-use user interface is provided both for a browser or stand-alone application. The entire method provides means by which users can establish, use, and maintain files on the Internet in a manner remote from their local computers yet in a manner that is similar to the file manipulation used on their local computers. A high capacity or other storage system is attached to the Internet via an optional internal network that also serves to generate and direct metadata regarding the stored files. A web server using a CGI, Java®-based, or other interface transmits and retrieves TCP/IP packets or other Internet information through a load balancer/firewall by using XML to wrap the data packets. File instructions may be transmitted over the Internet to the Shared Resource System. The user's account may be password protected so that only the user may access his or her files. On the user's side, a stand-alone client application or JavaScript object interpreted through a browser provide two means by which the XML or other markup language data stream may be received and put to use by the user. Internet-to-Internet file transfers may be effected by directly downloading to the user's account space.

539 citations


Patent
22 Jul 2005
TL;DR: In this article, a method for controlling a shared resource for interconnecting two or more network domains being controlled by different Managers is described, where multiple Managers control the shared resources for the configuration of a segment of a connection between two different domains and the Managers cooperate in order to control dynamically the shared resource.
Abstract: A method is described for controlling a shared resource for interconnecting two or more network domains being controlled by different Managers. Multiple Managers control the shared resource for the configuration of a segment of a connection between two different domains and the Managers cooperate in order to control dynamically the shared resource. Different network domains can be connected by a network element or by a link between different network elements belonging to the different network domains. In the first case the shared resource is a connection matrix of the network element, in the second case the shared resource includes the connection matrixes of the different network elements and the link between the network elements. A shared connection matrix includes some connection points for performing the cross-connections within the matrix: some connection points are controlled by one Manager, other connection points are controlled by another Manager and some shared connection points are controlled by both Managers. Multiple Managers control the shared resource by reading and writing information stored into a management information base, according to an explicit or implicit mode, or alternatevely by transmitting messages in the network directly between the Managers, according to a signalling protocol.

175 citations


Patent
Andre Eisenbach1
07 Mar 2005
TL;DR: In this article, the authors propose a method, apparatus, and system for automatically sharing data resources between Bluetooth devices, where a Bluetooth device is paired with a trusted Bluetooth device and when paired devices are found, the Bluetooth device automatically allows the other device to present a virtual representation of data that is shared.
Abstract: A method, apparatus, and system for automatically sharing data resources between Bluetooth devices. A Bluetooth device is paired with a “trusted” Bluetooth device. When paired devices are found, the Bluetooth device automatically allows the other device to present a virtual representation of data that is shared. The shared data can be selectively downloaded for use by the other device as long as the devices are in proximity. In an alternate embodiment, the devices may share pairing information with a network, so that the same shared resource can be made available at a large number of access points but specifically only for one paired, trusted device.

134 citations


Book ChapterDOI
24 Oct 2005
TL;DR: This paper identifies the nonlinear and bimodal properties of the models across different operating regions, and discusses their implications for the design of the control loops, and proposes two adaptive controllers for tracking the target utilization and target response time respectively.
Abstract: This paper deals with a shared server environment where the server is divided into a number of resource partitions and used to host multiple applications at the same time. In a case study where the HP-UX Process Resource Manager is taken as the server partitioning technology, we investigate the technical challenges in performing automated sizing of a resource partition using a feedback control approach, where the CPU entitlement for the partition is dynamically tuned to regulate output metrics such as the CPU utilization or SLO-based application performance metric. We identify the nonlinear and bimodal properties of the models across different operating regions, and discuss their implications for the design of the control loops. To deal with these challenges, we then propose two adaptive controllers for tracking the target utilization and target response time respectively. We evaluate the performance of the closed-loop systems while varying certain operating conditions. We demonstrate that better performance and robustness can be achieved with these controllers compared with other controllers or our prior solution.

125 citations


Proceedings ArticleDOI
12 Jul 2005
TL;DR: The Quartermaster capacity manager service implements a trace-based technique that models workload resource demands, their corresponding resource allocations, and resource access quality of service and is significantly more accurate at estimating per-server required capacity than a benchmark method used in practice to manage a resource pool.
Abstract: Resource pools are computing environments that offer virtualized access to shared resources. When used effectively they can align the use of capacity with business needs (flexibility), lower infrastructure costs (via resource sharing), and lower operating costs (via automation). This paper describes the Quartermaster capacity manager service for managing such pools. It implements a trace-based technique that models workload (e.g., application) resource demands, their corresponding resource allocations, and resource access quality of service. The primary advantages of the technique are its accuracy, generality, support for resource access qualities of service, and optimizing search method. We pose general capacity management questions for resource pools and explain how the capacity manager helps to address them in an automated manner. A case study demonstrates and validates the method on empirical data from an enterprise application. We show that the technique exploits much of the resource savings to be achieved from resource sharing and is significantly more accurate at estimating per-server required capacity than a benchmark method used in practice to manage a resource pool. Finally, we explain how the problems relate to other practices regarding enterprise capacity management and software performance engineering.

109 citations


Journal ArticleDOI
28 Feb 2005
TL;DR: A unifying resource management framework is presented in which to address the need to coordinate resource usage, the diversity of resource types and the variety of different management modes that may be used.
Abstract: One of the criteria for the Grid infrastructure is the ability to share resources with nontrivial qualities of service. However, sharing resources in Grids is complicated in that is requires the ability bridge the differing policy requirements of the resource owners to create a consistent cross-organizational policy domain that delivers the necessary capability to the end user while respecting the policy requirements of the resource owner. Further complicating the management of Grid resources is the need to coordinate resource usage, the diversity of resource types and the variety of different management modes that may be used. We present a unifying resource management framework in which we can address these issues. The fundamental underlying concept in this framework is the representation of various resource management activities in terms of an agreement. Agreements abstract local management policy by representing an underlying resource strictly in terms of policy terms which it is willing to assert, and in doing so provides the basis for building a variety of alternative Grid resource management strategies. We introduce the concepts of agreement based resource management. We present a general agreement model and examine current resource management systems in the context of this model. We then discuss how agreement based resource management is being used as the basis for standards activities and next generation resource management services.

105 citations


Patent
31 Oct 2005
TL;DR: In this paper, a certificate is used to identify a particular data requester and the certificate is authenticated using asymmetric encryption techniques, such as public-private key pairs, to provide varying levels of secure access to computer resources.
Abstract: A method of providing varying levels of secure access to computer resources. A certificate is used to identify a particular data requester and the certificate is authenticated using asymmetrical encryption techniques, such as public-private key pairs. One or more trust authorities may be consulted to ascribe a trust level to the certificate, which is an indication of the veracity of the identity of the data requester. Individual system users may set differing levels of access to a number of shared system resources for a particular data requester. The authenticated and verified data requester is then provided with the pre-set level of access to the desired shared resource. The level of access to a particular shared system resource therefore depends upon the user the data is being accessed through, the authenticated identity of the data requester, and their ascribed trust level. The shared resource may comprise data and/or an application module that is accessed or executed through a secure symmetric encryption tunnel.

88 citations


Posted Content
TL;DR: In this paper, the analysis of the LPC cluster usage (Clermont-Ferrand, France) in the EGEE Grid environment is done, and from the results a model for job arrival is proposed.
Abstract: With Grids, we are able to share computing resources and to provide for scientific communities a global trans-parent access to local facilities. In such an environment the problems of fair resource sharing and best usage arise. In this paper, the analysis of the LPC cluster usage (Clermont-Ferrand, France) in the EGEE Grid environment is done, and from the results a model for job arrival is proposed

79 citations


Book ChapterDOI
30 Aug 2005
TL;DR: GRUBER is described, an architecture and toolkit for resource usage service level agreement (SLA) specification and enforcement in a grid environment, and a series of experiments on a real grid, Grid3.
Abstract: Resource sharing within grid collaborations usually implies specific sharing mechanisms at participating sites. Challenging policy issues can arise in such scenarios that integrate participants and resources spanning multiple physical institutions. Resource owners may wish to grant to one or more virtual organizations (VOs) the right to use certain resources subject to local usage policies and service level agreements, and each VO may then wish to use those resources subject to its usage policies. This paper describes GRUBER, an architecture and toolkit for resource usage service level agreement (SLA) specification and enforcement in a grid environment, and a series of experiments on a real grid, Grid3. The proposed mechanism allows resources at individual sites to be shared among multiple user communities.

77 citations


Patent
21 Oct 2005
TL;DR: In this paper, the authors present an access management algorithm that permits multiple processes to concurrently obtain shared locks on the shared resource, but also limits access to only one process when an exclusive lock is granted.
Abstract: The systems and methods manage concurrent access requests to a shared resource. The systems and methods utilize an access management algorithm that permits multiple processes to concurrently obtain shared locks on the shared resource, but also limits access to only one process when an exclusive lock is granted. In doing so, the systems and methods avoid the problems of starvation and deadlock.

Book ChapterDOI
19 Jun 2005
TL;DR: The analysis of the LPC cluster usage in Clermont-Ferrand in the EGEE Grid environment is done, and from the results a model for job arrival is proposed.
Abstract: With Grids, we are able to share computing resources and to provide for scientific communities a global transparent access to local facilities. In such an environment the problems of fair resource sharing and best usage arise. In this paper, the analysis of the LPC cluster usage (Laboratoire de Physique Corpusculaire, Clermont-Ferrand, France) in the EGEE Grid environment is done, and from the results a model for job arrival is proposed.

Patent
28 Oct 2005
TL;DR: In this paper, the authors present methods and apparatus for implementing context-dependent security for files and other computer system resources, in particular, they implement context-based permissions that are used in contextdependent file security.
Abstract: The present invention concerns methods and apparatus for implementing context-dependent security for files and other computer system resources. In particular, methods and apparatus of the present invention implement context-based permissions that are used in context-dependent file security. In examples of the present invention, the context-based permissions may allow access to a file only when an attempt to access the file is made at a certain time of day, or from an authorized computer system, or from a computer having a certain application program installed. In general terms, the context-based permissions may specify time, location and application information that either alone or in combination may be used to restrict access to a file.

Patent
29 Jul 2005
TL;DR: In this paper, a system and method for producing variable length acknowledgments and requesting variable length acknowledgement signals in a shared resource network is provided, where a plurality of data streams and frames are received, and receipt status information of the plurality of frames is generated.
Abstract: A system and method for producing variable length acknowledgments and requesting variable length acknowledgement signals in a shared resource network is provided. A plurality of data streams and frames are received, and receipt status information of the plurality of frames is generated. An acknowledgment frame comprising the receipt status information is produced. A length of the receipt status information is dependent on a number of the plurality of frames.

Proceedings ArticleDOI
05 Dec 2005
TL;DR: This contribution presents a decentralized architecture for a grid-wide fairshare scheduling system that enforces locally and globally scoped share policies, allowing local resource capacity as well as global grid capacity to be logically divided across different groups of users.
Abstract: This contribution presents a decentralized architecture for a grid-wide fairshare scheduling system and demonstrates its potential in a simulated environment. The system, which preserves local site autonomy, enforces locally and globally scoped share policies, allowing local resource capacity as well as global grid capacity to be logically divided across different groups of users. The policy model is hierarchical and subpolicy definition can be delegated so that, e.g., a VO that has been granted a resource share can partition its share across its projects, which in turn can divide their shares between project members. There is no need for a central coordinator as policies are enforced collectively by the resource schedulers. Each local scheduler adopts a grid-wide view on utilization in order to steer local resource utilization to not only maintain local resource shares but also to contribute to maintaining global shares across the entire set of grid resources. Share enforcement is addressed by an algorithm that calculates simple priority values, thus simplifying integration with local schedulers, which can remain unaware of the hierarchical share policy structure

Proceedings ArticleDOI
25 Jul 2005
TL;DR: A formal model for indivisible goods resource sharing without monetary compensations and with arbitrary feasability constraints is given and is applied to a real-world case, namely satellite resource sharing.
Abstract: Many industrial or research activities are so expensive that it is often benefitable for the involved agents to cofund the construction or the purchase of a common required resource. This resource will then be exploited in common, therefore in a shared way. The rules for resource sharing should take account of the possibly antagonistic preferences: each agent wants to maximize its own satisfaction, whereas, from the collective point of view, decisions which both are equitable and exploit the resource in an optimal way are looked for. We give in this article a formal model for indivisible goods resource sharing without monetary compensations and with arbitrary feasability constraints. We also give some complexity results about this model. The model is applied to a real-world case, namely satellite resource sharing.

Journal ArticleDOI
TL;DR: A bandwidth-centric job communication model that captures the interaction and impact of simultaneously co-allocating jobs across multiple clusters is presented and the performance of multi-cluster scheduling algorithms that focus not only on node resource allocation, but also on shared inter-clusters network bandwidth is evaluated.
Abstract: In this paper, we present a bandwidth-centric job communication model that captures the interaction and impact of simultaneously co-allocating jobs across multiple clusters. We compare our dynamic model with previous research that utilizes a fixed execution time penalty for co-allocated jobs. We explore the interaction of simultaneously co-allocated jobs and the contention they often create in the network infrastructure of a dedicated computational multi-cluster. We also present several bandwidth-aware co-allocating meta-schedulers. These schedulers take inter-cluster network utilization into account as a means by which to mitigate degraded job run-time performance. We make use of a bandwidth-centric parallel job communication model that captures the time-varying utilization of shared inter-cluster network resources. By doing so, we are able to evaluate the performance of multi-cluster scheduling algorithms that focus not only on node resource allocation, but also on shared inter-cluster network bandwidth.

Book ChapterDOI
06 Apr 2005
TL;DR: A distributed solution for access control, making use of the autonomy and cooperation capability of the devices, since in open dynamic environments is very difficult to depend on central server.
Abstract: Alice first meets Bob in an entertainment shop, then, they wish to share multimedia content, but Do they know what are trustworthy users? How do they share such information in a secure way? How do they establish the permissions? Pervasive computing environments originate this kind of scenario, users with their personal devices interacting without need of wires, by forming ad-hoc networks. Such devices considered pervasive are having increasingly faster processors, larger memories and wider communication capabilities, which allows certain autonomy for collaborating and sharing resources. So, they require a suitable access control in order to avoid unauthorised access, or disclosure/modification of relevant information; in general, to protect the data that are usually confidential and the resources. This paper presents a distributed solution for access control, making use of the autonomy and cooperation capability of the devices, since in open dynamic environments is very difficult to depend on central server. The access control is based on a pervasive trust management model from which trust degrees are dynamically obtained. We present the TrustAC reference and functional model, as well as a prototype implementation using XACML-compliant policies.

Journal ArticleDOI
TL;DR: DartGrid II is currently using grid technology to build DartGrid II, a semantic ITS platform to support resource sharing, service flow management, and cross-domain cooperation.
Abstract: Intelligent transportation systems offer an alternative approach to solving many problems by implementing advances in information, Internet, communication, and cybernetics technologies. Grid computing can support traffic data semantization, resource sharing, ITS subsystem cooperation, and global-scale distributed computing that connects all kinds of resources. We are currently using grid technology to build DartGrid II, a semantic ITS platform to support resource sharing, service flow management, and cross-domain cooperation.

Patent
02 Sep 2005
TL;DR: In this article, a measure of urgency of allocation derived from the size of the resource occupier, the resource available, and the time remaining in which to allocate resource to the occupier is defined.
Abstract: Methods, apparatus, systems, and programs for computers are provided for automatic allocation of resource occupiers (e.g. data, people) to available resources (e.g. bandwidth, radio frequency spectrum, theatre seats). Allocation of resources to resource occupiers is based on a measure of urgency of allocation derived from the size of the resource occupier, the resource available, and the time remaining in which to allocate resource to the resource occupier. One, two, or more time thresholds may be associated with each resource occupier: in particular a timeliness threshold up to which allocation urgency increases but after which it decreases, and a perishability threshold after which allocation of resource to the resource occupier ceases to be at all useful, and after which no more resource is allocated. Also automated auction methods, systems, and programs for real­time allocation of radio frequency spectrum.

Proceedings ArticleDOI
01 Jan 2005
TL;DR: This work studies survivable service provisioning under a scheduled traffic model in wavelength convertible WDM optical mesh networks and indicates that joint optimization of resource sharing in space and time enabled by connection holding-time aware protection schemes can achieve significantly better resource utilization.
Abstract: We study survivable service provisioning under a scheduled traffic model in wavelength convertible WDM optical mesh networks. In this model, a set of demands is given, and the setup time and teardown time of each demand are known in advance. We formulate the problem as integer linear programs that maximally exploit network resource reuse in both space and time. The objective is to minimize the total number of wavelength-links used by working paths and protection paths of all traffic demands while 100% restorability is guaranteed against any single failures. Our simulation results indicate that joint optimization of resource sharing in space and time enabled by our connection holding-time aware protection schemes can achieve significantly better resource utilization than schemes that are holding-time unaware

Journal ArticleDOI
TL;DR: This work discusses the evolution of W-LANs from their current status of wireless termination of LAN services to a possible global infrastructure where the access networks become open to multiple operators and a vehicle of a win-win scenario, where both users and operators benefit from the new network architecture.
Abstract: This work discusses the evolution of W-LANs from their current status of wireless termination of LAN services to a possible global infrastructure where the access networks become open to multiple operators and a vehicle of a win-win scenario, where both users and operators benefit from the new network architecture. The idea of Open Access Networks (OANs) can go beyond wireless HotSpots and be generalized to a generic shared access infrastructure that fosters service operators competition and drastically reduces the cost of last mile coverage.The general concept of Open Access Networks is detailed, highlighting its difference with the more traditional model of vertical integration of the access network into the global service. About the OANs development, it is shown how to support the quick and smooth evolution of the infrastructure toward a widespread and reliable communication support.Business models are discussed by mentioning the different actors, the market organization and the different organization forms.The final part of the paper is devoted to technical challenges such as access control, security, privacy, roaming, resource exploitation and service differentiation. As an example of how to tackle these problems, we discuss a pricing technique devoted to resource management and billing support.In addition we present a simulation on how the OAN concept can speed-up the deployment of broadband access in a real case.

Patent
02 Mar 2005
TL;DR: In this article, the authors present a system consisting of a Central Processing Unit (CPU), Virtual Machines (VMs), and a first isolated driver domain in which a first device driver for a first shared resource resides.
Abstract: According to at least one embodiment, a method comprises observing communication from a virtual machine (VM) to an isolated driver domain. The method further comprises determining, based on the observed communication, CPU utilization of the isolated driver domain that is attributable to the VM. According to at least one embodiment, a system comprises a Central Processing Unit (CPU), Virtual Machines (VMs), and a first isolated driver domain in which a first device driver for a first shared resource resides, wherein the first isolated driver domain is operable to receive requests from the VMs for access to the first shared resource. The system further comprises a CPU utilization monitor operable to determine an amount of CPU utilization of the first isolated driver domain in processing the received requests that is attributable to a VM requesting access to the first shared resource.

Journal ArticleDOI
TL;DR: This work presents a self-policing and distributed approach by combining two models: PET, a personalized trust model, and M-CUBE, a multiple-currency based economic model, to lay a foundation for resource sharing in untrusted P2P computing environments.
Abstract: Peer-to-Peer (P2P) computing is widely recognized as a promising paradigm for building next generation distributed applications. However, the autonomous, heterogeneous, and decentralized nature of participating peers introduces the following challenge for resource staring: how to make peers profitable in the untrusted P2P environment? To address the problem, we present a self-policing and distributed approach by combining two models: PET, a personalized trust model, and M-CUBE, a multiple-currency based economic model, to lay a foundation for resource sharing in untrusted P2P computing environments. PET is a flexible trust model that can adapt to different requirements, and provides the solid support for the currency management in M-CUBE. M-CUBE provides a novel self-policing and quality-aware framework for the sharing of multiple resources, including both homogeneous and heterogeneous resources. We evaluate the efficacy and performance of this approach in the context of a real application, a peer-to-peer Web server sharing. Our results show that our approach is flexible enough to adapt to different situations and effective to make the system profitable, especially for systems with large scale.

Proceedings Article
13 Sep 2005
TL;DR: This article presents a framework intended to help developers in the task of designing dynamically adaptable (but not fault-tolerant) components and puts the emphasis on an experimental evaluation of the cost of using such a framework.
Abstract: The emergence of dynamic execution environments such as Grids forces applications to take dynamicity into account. Whereas sudden resource disappearance can be handled thanks to fault-tolerance techniques, these approaches are usually not well suited when resource disappearance is announced in advance. However, this case occurs in particular for resource preemption due to resource sharing or maintenance operations. Similarly, fault-tolerance techniques commonly do not take into account resource appearance. On the other side, dynamic adaptation covers techniques for handling changes in the execution environment. This article presents a framework intended to help developers in the task of designing dynamically adaptable (but not fault-tolerant) components. This article puts the emphasis on an experimental evaluation of the cost of using such a framework.

Journal ArticleDOI
TL;DR: Simulation results show that 80% of the telecommunication cost is saved with as few as six peers, and with support from the servers in the internet, peers receive benefits of reduced telecommunication bandwidth, computation power, as well as several security features.
Abstract: Summary This paper provides a scheme to reduce the cost to distribute multimedia content to a set of nearby mobile peers, which we call chums. One peer, called the proxy, downloads multimedia content via a telecommunication link, and distributes it (which we call chumcast) to the ad hoc network formed from the set of nearby peers. Each peer in the ad hoc network takes turns serving as a proxy. Every peer is associated with a server that resides in the internet. The server for the proxy, called the active server, manages peer information, schedules the next proxy, selects a set of rebroadcasting peers, and detects partitioning of the ad hoc network. With support from the servers in the internet, peers receive benefits of reduced telecommunication bandwidth, computation power, as well as several security features. Simulation results show that 80% of the telecommunication cost is saved with as few as six peers. Copyright # 2005 John Wiley & Sons, Ltd.

Proceedings ArticleDOI
25 Jul 2005
TL;DR: A multi-agent based reciprocity mechanism where each user's agent makes the decision to share a resource with a requesting user based on the amount of resources previously provided by the requesting user to the providing user and globally in the system is described.
Abstract: Peer-to-peer (P2P) systems enable users to share resources in a networked environment without worrying about issues such as scalability and load balancing. Unlike exchange of goods in a traditional market, resource exchange in P2P networks does not involve monetary transactions. This makes P2P systems vulnerable to problems including the free-rider problem that enables users to acquire resources without contributing anything, collusion between groups of users to incorrectly promote or malign other users, and zero-cost identity that enables nodes to obliterate unfavorable history without incurring any expenditure. Previous research addresses these issues using user-reputation, referrals, and shared history based techniques. Here, we describe a multi-agent based reciprocity mechanism where each user's agent makes the decision to share a resource with a requesting user based on the amount of resources previously provided by the requesting user to the providing user and globally in the system. A robust reputation mechanism is proposed to avoid the differential exploitations by the free-riders and to prevent collusion. Experimental results on a simulated P2P network addresses the problems identified above and shows that users adopting the reciprocative mechanism outperform users that do not share resources in the P2P network. Hence, our proposed reciprocative mechanism effectively suppresses free-riding.

Journal ArticleDOI
TL;DR: The paper discusses the importance of embedding supportive technologies and the different forms of learner collaboration mediated by each technology in order to improve group sharing of resources and supported different kinds of group collaboration.
Abstract: Two different technologies, groupware (a shared workspace) and shared wireless laptop computers, were implemented in a project design class in a civil engineering course. The research interest was in the way these technologies supported resource sharing within and across project groups and in the forms of group collaboration that resulted. The initiative was evaluated using both qualitative (e.g. pyramid discussion) and quantitative methods (e.g. survey, logs of usage). The results showed that these technologies helped improve group sharing of resources and supported different kinds of group collaboration. The shared workspace provided a location-independent central repository of resources around which group activities were coordinated whereas the laptops provided a focal point for the face-to-face discussion of these resources. The paper discusses the importance of embedding supportive technologies and the different forms of learner collaboration mediated by each technology.

Proceedings ArticleDOI
V.K. Naik1, Chuang Liu, L. Yang, J. Wagner
09 May 2005
TL;DR: Preliminary performance results indicate that the linear programming based approach for resource matching is efficient in speed and accuracy and can keep up with high job arrival rates of an important criterion for online resource matching systems.
Abstract: In this paper, we first present a linear programming based approach for modeling and solving the resource matching problem in grid environments with heterogeneous resources. The resource matching problem described takes into account resource sharing, job priorities, dependencies on multiple resource types, and resource specific policies. We then propose Web service style architecture for online matching of independent jobs with resources in a grid environment and describe a prototype implementation. Our preliminary performance results indicate that the linear programming based approach for resource matching is efficient in speed and accuracy and can keep up with high job arrival rates of an important criterion for online resource matching systems. Also, the Web service style architecture makes the system scalable and extendable. It can also be integrated with other existing grid services in a straightforward manner.

Patent
Gavin Barraclough1, Paul Knowles1
02 Sep 2005
TL;DR: A dynamic binary translator as mentioned in this paper converts a subject program into target code on a target processor by providing a global token common to each thread and one or more sets of local data, which together coordinate access to a memory as a shared resource.
Abstract: A dynamic binary translator 19 converts a subject program 17 into target code 21 on a target processor 13 . For a multi-threaded subject environment, the translator 19 provides a global token 501 common to each thread 171, 172 , and one or more sets of local data 502 , which together are employed to coordinate access to a memory 18 as a shared resource. Adjusting the global token 501 allows the local datastructures 502 a,b in each thread to detect potential interference with the shared resource 18.