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Processing Regular Path Queries on Arbitrarily Distributed Data [article]

Alan Davoust, Babak Esfandiari
2015 arXiv   pre-print
Regular Path Queries (RPQs) are a type of graph query where answers are pairs of nodes connected by a sequence of edges matching a regular expression. We study the techniques to process such queries on a distributed graph of data. While many techniques assume the location of each data element (node or edge) is known, when the components of the distributed system are autonomous, the data will be arbitrarily distributed. As the different query processing strategies are equivalently costly in the
more » ... orst case, we isolate query-dependent cost factors and present a method to choose between strategies, using new query cost estimation techniques. We evaluate our techniques using meaningful queries on biomedical data.
arXiv:1510.04347v1 fatcat:xmamt2spevhf7cz4aea5ur5diu

Distributed wikis: a survey

Alan Davoust, Hala Skaf-Molli, Pascal Molli, Babak Esfandiari, Khaled Aslan
2014 Concurrency and Computation  
Distributed Wiki" is a generic term covering various systems, including "peer-to-peer wiki," "mobile wiki," "offline wiki," "federated wiki" and others. Distributed wikis distribute their pages among the sites of autonomous participants to address various motivations, including high availability of data, new collaboration models and different viewpoint of subjects. Although existing systems share some common basic concepts, it is often difficult to understand the specificity of each one, the
more » ... erlying complexities or the best context in which to use it. In this paper, we define, classify and characterize distributed wikis. We identify three classes of distributed wiki systems, each using a different collaboration model and distribution scheme for its pages: highly available wikis, decentralized social wikis and federated wikis. We classify existing distributed wikis according to these classes. We detail their underlying complexities and social and technical motivations. We also highlight some directions for research and opportunities for new systems with original social and technical motivations.
doi:10.1002/cpe.3439 fatcat:ysgby7beqzhsfiznwjaqec2edu

Linking and Navigating Data in a P2P File-Sharing Network

Alan Davoust, Babak Esfandiari
2009 The Web Conference  
We demonstrate a tool for publishing and navigating linked data over the highly dynamic infrastructure of a P2P filesharing network. Our links are based on a URI scheme which allows unambiguous designation of replicated data items, regardless of their location in the network. In a true decentralized P2P spirit, users publish and distribute the links just like other data items.
dblp:conf/www/DavoustE09 fatcat:z7lsryj3wrfr5da5tmrsarzcyy

Processing Regular Path Queries on Arbitrarily Distributed Data [chapter]

Alan Davoust, Babak Esfandiari
2016 Lecture Notes in Computer Science  
Regular Path Queries (RPQs) are a type of graph query where answers are pairs of nodes connected by a sequence of edges matching a regular expression. We study the techniques to process such queries on a distributed graph of data. While many techniques assume the location of each data element (node or edge) is known, when the components of the distributed system are autonomous, the data will be arbitrarily distributed, or non-localized. We compare query processing strategies for this setting
more » ... lytically and empirically, using biomedical data and meaningful queries. We isolate query-dependent cost factors and present a method to choose between strategies, using new query cost estimation techniques.
doi:10.1007/978-3-319-48472-3_53 fatcat:kmd6bdhwkjefhd6qwdxziwdqru

Social Contracts for Non-Cooperative Games

Alan Davoust, Michael Rovatsos
2020 Proceedings of the AAAI/ACM Conference on AI, Ethics, and Society  
In future agent societies, we might see AI systems engaging in selfish, calculated behavior, furthering their owners' interests instead of socially desirable outcomes. How can we promote morally sound behaviour in such settings, in order to obtain more desirable outcomes? A solution from moral philosophy is the concept of a social contract, a set of rules that people would voluntarily commit to in order to obtain better outcomes than those brought by anarchy. We adapt this concept to a
more » ... retic setting, to systematically modify the payoffs of a non-cooperative game, so that agents will rationally pursue socially desirable outcomes. We show that for any game, a suitable social contract can be designed to produce an optimal outcome in terms of social welfare. We then investigate the limitations of applying this approach to alternative moral objectives, and establish that, for any alternative moral objective that is significantly different from social welfare, there are games for which no such social contract will be feasible that produces non-negligible social benefit compared to collective selfish behaviour. CCS CONCEPTS • Computing methodologies → Cooperation and coordination; Philosophical/theoretical foundations of artificial intelligence; Multi-agent systems.
doi:10.1145/3375627.3375829 dblp:conf/aies/DavoustR20 fatcat:x4mx5r4yjferhnvpbvc3gaewoe

Towards Executable Representations of Social Machines [chapter]

Dave Murray-Rust, Alan Davoust, Petros Papapanagiotou, Areti Manataki, Max Van Kleek, Nigel Shadbolt, Dave Robertson
2018 Lecture Notes in Computer Science  
Human interaction is increasingly mediated through technological systems, resulting in the emergence of a new class of socio-technical systems, often called Social Machines. However, many systems are designed and managed in a centralised way, limiting the participants' autonomy and ability to shape the systems they are part of. In this paper we are concerned with creating a graphical formalism that allows novice users to simply draw the patterns of interaction that they desire, and have
more » ... ional infrastructure assemble around the diagram. Our work includes a series of participatory design workshops, that help to understand the levels and types of abstraction that the general public are comfortable with when designing socio-technical systems. These design studies lead to a novel formalism that allows us to compose rich interaction protocols into functioning, executable architecture. We demonstrate this by translating one of the designs produced by workshop participants into an a running agent institution using the Lightweight Social Calculus (LSC).
doi:10.1007/978-3-319-91376-6_77 fatcat:chba5kdxkvbpvla2zmod7vo7ly

DEVS simulation of peer-to-peer file-sharing

Alan Davoust, Gabriel Wainer, Babak Esfandiari
2012 2012 International Conference on High Performance Computing & Simulation (HPCS)  
We present a framework to simulate a peer-topeer (P2P) file-sharing network, based on the Discrete Event Systems Specification (DEVS) formalism. Our framework models a file-sharing network as a coupled model, comprising a network model and a large number of peer models. While most available network simulation tools focus on transportlevel dynamics, we provide extensible and reusable models for the file-sharing protocol and for the behavior of peers. These models, implemented using the CD++
more » ... it, can readily be used on existing simulators, including parallel and real-time simulators. As a case study, we apply our framework to simulate a P2P web, and show the emergence of an interesting page distribution.
doi:10.1109/hpcsim.2012.6266937 dblp:conf/ieeehpcs/DavoustWE12 fatcat:nmix3zpvpzh4fdeub5f757gxly

Decentralized collaboration with a peer-to-peer wiki

Alan Davoust, Alexander Craig, Babak Esfandiari, Vincent Kazmierski
2012 2012 International Conference on Collaboration Technologies and Systems (CTS)  
We report our experience using a peer-to-peer (P2P) wiki system for academic writing tutorials. Our wiki system supports a non-traditional collaboration model, where each participant maintains their own version of the documents. The users share their contributions in the P2P network, which allows them to be exposed to multiple viewpoints, and to reuse each other's work. We collected and analyzed the contributions of the participants to these tutorials, and the results demonstrate the value of
more » ... is collaboration model. In particular, we found the popularity of a document in the system is correlated with its quality, and the similarity between contributions of peers is a good predictor of future similarities. These properties provide helpful criteria for users to identify valuable material for reuse.
doi:10.1109/cts.2012.6261064 dblp:conf/cts/DavoustCEK12 fatcat:bm735qub3zg4vpu5acbzhssn5e

"It would be pretty immoral to choose a random algorithm"

Helena Webb, Menisha Patel, Michael Rovatsos, Alan Davoust, Sofia Ceppi, Ansgar Koene, Liz Dowthwaite, Virginia Portillo, Marina Jirotka, Monica Cano
2019 Journal of Information, Communication and Ethics in Society  
doi:10.1108/jices-11-2018-0092 fatcat:6q5qfv5xwrbmffcptgircveoma

Towards Securing Peer-to-Peer SIP in the MANET Context: Existing Work and Perspectives

Alan Davoust, Francois Gagnon, Babak Esfandiari, Thomas Kunz, Alexandre Cormier
2017 2017 IEEE International Conference on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData)  
The Session Initiation Protocol (SIP) is a key building block of many social applications, including VoIP communication and instant messaging. In its original architecture, SIP heavily relies on servers such as proxies and registrars. Mobile Ad hoc NETworks (MANETs) are networks comprised of mobile devices that communicate over wireless links, such as tactical radio networks or vehicular networks. In such networks, no fixed infrastructure exists and server-based solutions need to be redesigned
more » ... o work in a peer-to-peer fashion. We survey existing proposals for the implementation of SIP over such MANETs and analyze their security issues. We then discuss potential solutions and their suitability in the MANET context.
doi:10.1109/ithings-greencom-cpscom-smartdata.2017.38 dblp:conf/ithings/DavoustGEKC17 fatcat:7dsy4pdfj5en3hyg4hi5j2csyi


Beatrice Bucciarelli, Alain Fresnau, Carlos Abad, Robert W. Argyle, James Biggs, Noah Brosch, George V. Coyne, Emmanuael Davoust, Jean-Pierre M. De Cuyper, Edwin L. van Dessel, Christine Ducourant, Ivan H. Bustos Fierro (+14 others)
2007 Proceedings of the International Astronomical Union  
Various experiments have definitely demonstrated that one-micron accuracy (0.″06) on the definition of stellar images on CdC plates cannot be claimed, as it was speculated back in 1999. More realistically, a 2-3 micron accuracy is achievable, getting worse toward the survey magnitude limit, with an average magnitude error of 0.3. The level of astrometric accuracy corresponds to a 0.″2 - 0.″3 error in position at Epoch 1900, which, once used as first Epoch for proper motion determination in
more » ... nation with modern epoch observations, can produce errors at the level of 2-5 mas/yr, thereby allowing to detect stellar motions larger than 0.″01/yr, which at a distance of 500 pc from the Sun correspond to ~25-60 km/s tangential velocity. Therefore, the AC/CdC heritage collection can be regarded as a highly valuable first-epoch material, e.g., for the realization of a Tycho-2 extension to fainter magnitudes (~15 photographic), especially in selected areas where radial velocity data are available, for the exploration of stellar kinematics beyond our solar neighborhood.
doi:10.1017/s1743921308023727 fatcat:hapow3pxhvhmrbduz4v3plfps4

Use of Fuzzy Histograms to Model the Spatial Distribution of Objects in Case-Based Reasoning [chapter]

Alan Davoust, Michael W. Floyd, Babak Esfandiari
Advances in Artificial Intelligence  
In the context of the RoboCup Simulation League, we describe a new representation of a software agent's visual perception ("scene"), well suited for case-based reasoning. Most existing representations use either heterogeneous, manually selected features of the scene, or the raw list of visible objects, and use ad hoc similarity measures for CBR. Our representation is based on histograms of objects over a partition of the scene space. This method transforms a list of objects into an image-like
more » ... presentation with customizable granularity, and uses fuzzy logic to smoothen boundary effects of the partition. We also introduce a new similarity metric based on the Jaccard Coefficient, to compare scenes represented by such histograms. We present our implementation of this approach in a case-based reasoning project, and experimental results showing highly efficient scene comparison.
doi:10.1007/978-3-540-68825-9_8 dblp:conf/ai/DavoustFE08 fatcat:ibsdzqblezapnahpdxjhpmbyte

Considerations for Real-Time Spatially-Aware Case-Based Reasoning: A Case Study in Robotic Soccer Imitation [chapter]

Michael W. Floyd, Alan Davoust, Babak Esfandiari
Lecture Notes in Computer Science  
Case-base reasoning in a real-time context requires the system to output the solution to a given problem in a predictable and usually very fast time frame. As the number of cases that can be processed is limited by the real-time constraint, we explore ways of selecting the most important cases and ways of speeding up case comparisons by optimizing the representation of each case. We focus on spatially-aware systems such as mobile robotic applications and the particular challenges in
more » ... the systems' spatial environment. We select and combine techniques for feature selection, clustering and prototyping that are applicable in this particular context and report results from a case study with a simulated RoboCup soccer-playing agent. Our results demonstrate that preprocessing such case bases can significantly improve the imitative ability of an agent.
doi:10.1007/978-3-540-85502-6_13 fatcat:aaeez3fhcbaejewfwg5bi6kfs4

An Overview of Lidar-Assisted Control

Eric Simley, David Schlipf, Andrew Scholbrock
2020 Zenodo  
Davoust, E. Osler, A. D. Wright, and A.  ...  Davoust, E. Osler, A. D. Wright, and A.  ... 
doi:10.5281/zenodo.3763079 fatcat:xnx76l43xzfrncu22zu6pafpoa

PAR volume 148 issue 11 Cover and Back matter

2021 Parasitology  
Medeiros, Alan L. Melo, Nelson R. S. Martins and Hudson A.  ...  tamarins ( Saguinus midas , Linnaeus, 1758) in French Guiana Younes Laidoudi, Riccardo Paolo Lia, Jairo Alfonso Mendoza-Roldan, David Modrý, Charles-Arnaud de Broucker, Oleg Mediannikov, Bernard Davoust  ... 
doi:10.1017/s0031182021001268 fatcat:alcwmbfcgjam5kzgt56upmx3ua
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