the proceedings contain 22 papers. the topics discussed include: collaboration using social media: the case of podio in a voluntary organization;keep querying and tag on: collaborative folksonomy using model-based rec...
ISBN:
(纸本)9783642413469
the proceedings contain 22 papers. the topics discussed include: collaboration using social media: the case of podio in a voluntary organization;keep querying and tag on: collaborative folksonomy using model-based recommendation;understanding real-world events via multimedia summaries based on social indicators;how do researchers on collaboration technology collaborate with each other? a social network analysis;inferring hidden trust relationships in social networks for encouraging collaboration and cooperation among individuals;providing awareness, understanding and control of personalized stream filtering in a P2P social network;a theoretical model of user engagement in crowdsourcing;factors influencing the decision to crowdsource;data quality in an output-agreement game: a comparison between game-generated tags and professional descriptors;and work and learning across boundaries: artifacts, discourses, and processes in a university course.
A polarized version of Girard, Scedrov and Scott's Bounded Linear Logic is introduced and its normalization properties studied. Following Laurent [25], the logic naturally gives rise to a type system for the λμ-...
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P2P protocols are responsible for a large amount of the Internet traffic. Given that in such systems each node functions both as a client and as a server, peer connectivity is an important element that influences the ...
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ISBN:
(纸本)9781467361408
P2P protocols are responsible for a large amount of the Internet traffic. Given that in such systems each node functions both as a client and as a server, peer connectivity is an important element that influences the overall system performance. the introduction of IPv6 solves a part of the NAT traversal connectivity problems that IPv4 had, and allows a larger number of peers to be connectable from the Internet. Moreover, it introduces built-in IPsec capabilities, lowering the overhead security features bring on the network stack. this places P2P systems in an area that would most benefit from IPv6 deployment. Considering that P2P systems mostly rely of the resources provided by each user, the information collected by measuring such systems offers a real image on the hardware and Internet connection available to the home users. For many years BitTorrent has been the P2P protocol withthe largest contribution to the P2P traffic in the Internet. this paper analyses one of the peer discovery methods available in BitTorrent, DHT, and compares the number of IPv4 and IPv6 node addresses that are available in the DHT system. the paper results are based on an experiment that measured the largest public swarms available on the file-sharing community called the Pirate Bay.
the pipe programming paradigm is an important Unix innovation which lets processes filter data to obtain a desired output. Extending computation in an Internet distributed environment has led us to design so called lo...
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ISBN:
(纸本)9781467361408
the pipe programming paradigm is an important Unix innovation which lets processes filter data to obtain a desired output. Extending computation in an Internet distributed environment has led us to design so called long and large pipes which achieve high speed transfer rates between remotely interconnected processes. Our method combines, in a full-fledged client/server application, the use of classical pipes, as a mean of serializing data locally, with multiple parallel TCP connections which yield high bandwidththroughput. the application, called bbftpPRO, brings together the old fashioned techniques of file striping withthe new data streaming algorithms at high transfer rates. It includes capabilities for easy traversal of networks protected by firewalls or NAT machines, split-TCP like path support, and last but not least, support for new transmission procedures at variable rate, adapted for multipath implementation at application level. Experimental results have proven the superiority of the proposed data transfer system. Both simple file transfers and arbitrary data streaming were done effectively, efficiently, in parallel, over wide area networks, between pairs of distributed processes connected via extended fast pipes. Our piped approach proved to be portable across heterogeneous systems and most suitable for data intensive computing applications requiring geographically distributed data.
While the problem of packing two-dimensional squares into a square, in which a set of squares is packed into a big square, has been proved to be NP-complete, the computational complexity of the d-dimensional (d > 2...
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A new challenge for web developers nowadays is the personalization of the social web. this means extracting data about something from different sources of information. the goal is to obtain relevant information and to...
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ISBN:
(纸本)9781467361408
A new challenge for web developers nowadays is the personalization of the social web. this means extracting data about something from different sources of information. the goal is to obtain relevant information and to create meaningful relations among data, using ontology based knowledge representation. therefore, there is a need to talk about semantic web and certain projects that have the purpose to create communities of related entities. the solution proposed in this paper aims to generate a profile for a person, from a scientific point of view; it shows all the research a person has made, with who, and in what periods of time. It is based on a Semantic web project, the FOAF (Friend of a Friend) model. the profiles are made for a small community belonging to the computerscience domain. the information scientific performance is extracted from different digital libraries, such as DBLP and ACM Digital Libraries. this project has a user-friendly graphical interface that allows a client, on the one hand, to insert a person's name and then to be shown the FOAF profile of the queried name, highlighting different attributes and collaborations of the person, and on the other hand, to give a list of people and to receive a list of articles they have in common. the information was extracted from the digital libraries mentioned above and we started from the premise that the data is accurate. the impact of our approach is sustained by the fact that in a small community, it is important to keep track of the research within it and the relations and collaborations between people.
Functional encryption (FE) enables fine-grained access control of encrypted data while promising simplified key management. In the past few years substantial progress has been made on functional encryption and a weake...
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ISBN:
(纸本)9783642420450;9783642420443
Functional encryption (FE) enables fine-grained access control of encrypted data while promising simplified key management. In the past few years substantial progress has been made on functional encryption and a weaker variant called predicate encryption. Unfortunately, fundamental impossibility results have been demonstrated for constructing FE schemes for general functions satisfying a simulation-based definition of security. We show how to use hardware tokens to overcome these impossibility results. In our envisioned scenario, an authority gives a hardware token and some cryptographic information to each authorized user;the user combines these to decrypt received ciphertexts. Our schemes rely on stateless tokens that are identical for all users. (Requiring a different token for each user trivializes the problem, and would be a barrier to practical deployment.) the tokens can implement relatively "lightweight" computation relative to the functions supported by the scheme. Our token-based approach can be extended to support hierarchal functional encryption, function privacy, and more.
the paper presents the considerations on the method which enables to accelerate the exchange of data in distributed control system, using multi-protocol nodes. the method presented in this paper is related to hardware...
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ISBN:
(纸本)9783642388651
the paper presents the considerations on the method which enables to accelerate the exchange of data in distributed control system, using multi-protocol nodes. the method presented in this paper is related to hardware and software, and based on new original communication protocol, which is used by the node for supporting various communication protocols to simultaneous data exchange via different buses. this method will enable to increase not only network bandwidth, but also the security of data transmission.
the proceedings contain 52 papers. the topics discussed include: an algorithm for enumerating maximal models of horn theories with an application to modal logics;may-happen-in-parallel analysis for priority-based sche...
ISBN:
(纸本)9783642452208
the proceedings contain 52 papers. the topics discussed include: an algorithm for enumerating maximal models of horn theories with an application to modal logics;may-happen-in-parallel analysis for priority-based scheduling;a semantic basis for proof queries and transformations;expressive path queries on graphs with data;dynamic and static symmetry breaking in answer set programming;resourceful reachability as HORN-LA;comparison of LTL to deterministic Rabin automata translators;towards rational closure for fuzzy logic: the case of propositional Gödel Logic;multi-objective discounted reward verification in graphs and MDPs;complexity analysis in presence of control operators and higher-order functions;Zenon Modulo: when Achilles outruns the tortoise using deduction modulo;long-distance resolution: proof generation and strategy extraction in search-based QBF solving;and a proof of strong normalisation of the typed atomic lambda-calculus.
To face the advent of multicore processors and the ever increasing complexity of hardware architectures, programming models based on DAG parallelism regained popularity in the high performance, scientific computing co...
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ISBN:
(纸本)9783642400476
To face the advent of multicore processors and the ever increasing complexity of hardware architectures, programming models based on DAG parallelism regained popularity in the high performance, scientific computing community. Modern runtime systems offer a programming interface that complies withthis paradigm and powerful engines for scheduling the tasks into which the application is decomposed. these tools have already proved their effectiveness on a number of dense linear algebra applications. this paper evaluates the usability of runtime systems for complex applications, namely, sparse matrix multifrontal factorizations which constitute extremely irregular workloads, with tasks of different granularities and characteristics and with a variable memory consumption. Experimental results on real-life matrices show that it is possible to achieve the same efficiency as with an ad hoc scheduler which relies on the knowledge of the algorithm. A detailed analysis shows the performance behavior of the resulting code and possible ways of improving the effectiveness of runtime systems.
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