Network services are provided by means of dedicated service gateways, through which traffic flows... more Network services are provided by means of dedicated service gateways, through which traffic flows are directed. Existing work on service gateway placement has been primarily focused on minimizing the length of the routes through these gateways. Only limited attention has been paid to the effect these routes have on overall network performance. We propose a novel approach for the service placement problem, which takes into account traffic engineering considerations. Rather than trying to minimize the length of the traffic flow routes, we take advantage of these routes in order to enhance the overall network performance. We divide the problem into two sub-problems: finding the best location for each service gateway, and selecting the best service gateway for each flow. We propose efficient algorithms for both problems and study their performance. Our main contribution is showing that placement and selection of network services can be used as effective tools for traffic engineering.
In this paper, we propose a novel network design algorithm that yields the hierarchical optical p... more In this paper, we propose a novel network design algorithm that yields the hierarchical optical path network with dedicated wavelength path protection. A hierarchical optical path network provides two granularities in implementing dedicated protection in the optical layer, namely waveband path protection and wavelength path protection. The characteristics of both protection mechanisms are investigated. We develop the concept of the source-destination Cartesian product space to aggregate closely located traffic demands, which leads to a significant reduction in network resources needed. The proposed wavelength path protection algorithm achieves lower network costs than that possible with waveband protection when traffic volume is relatively small. On the other hand, in the large traffic demand area, both schemes offer almost the same cost, which makes the waveband protection scheme attractive because of its operational simplicity. Numerical results clarify that survivable hierarchical optical path network is more cost effective than the single layer optical path network with optical layer protection, irrespective of which protection scheme is utilized.
In dependable embedded systems, it is current practice to assign each application subsystem to a ... more In dependable embedded systems, it is current practice to assign each application subsystem to a dedicated processor. However, several activities aim at an integrated approach, allowing the deployment of multiple application subsystems on a single distributed computer system . The resulting large number of feasible allocations of tasks to processors makes it hard for the developer to determine an optimal solution, and therefore automatic allocation is desirable. This paper presents an allocation algorithm that takes advantage of the existence of replicated software and hardware components in dependable embedded systems and the resultant symmetric solutions in order to minimize the number of allocations taken into consideration.
Wireless sensor networks are evolving from dedicated application-specific platforms to integrated... more Wireless sensor networks are evolving from dedicated application-specific platforms to integrated infrastructure shared by multiple applications. Shared sensor networks offer inherent advantages in terms of flexibility and cost since they allow dynamic resource sharing and allocation among multiple applications. Such shared systems face the critical need for allocation of nodes to contending applications to enhance the overall Quality of Monitoring (QoM) under resource constraints.
RDF is a knowledge representation language dedicated to the annotation of resources within the fr... more RDF is a knowledge representation language dedicated to the annotation of resources within the framework of the semantic web. Among the query languages for querying an RDF knowledge base, some, such as SPARQL, are based on the formal semantics of RDF and the concept of semantic consequence, others, inspired by the work in databases, use regular expressions making it possible to search the paths in the graph associated with the knowledge base. In order to combine the expressivity of these two approaches, we define a mixed language, called PRDF (for "Paths RDF") in which the arcs of a graph can be labeled by regular expressions. We define the syntax and the semantics of these objects, and propose a correct and complete algorithm which, by a kind of homomorphism, calculates the semantic consequence between an RDF graph and a PRDF graph. This algorithm is the heart of query answering for the PSPARQL query language, the extension of the SPARQL query language which we propose and have implemented: a PSPARQL query allows to query an RDF knowledge base using graph patterns whose predicates are regular expressions.
The hepatitis C virus (HCV) genome shows remarkable sequence variability, leading to the classifi... more The hepatitis C virus (HCV) genome shows remarkable sequence variability, leading to the classification of at least six major genotypes, numerous subtypes and a myriad of quasispecies within a given host. A database allowing researchers to investigate the genetic and structural variability of all available HCV sequences is an essential tool for studies on the molecular virology and pathogenesis of hepatitis C as well as drug design and vaccine development. We describe here the European Hepatitis C Virus Database (euHCVdb, http://euhcvdb.ibcp.fr), a collection of computer-annotated sequences based on reference genomes. The annotations include genome mapping of sequences, use of recommended nomenclature, subtyping as well as three-dimensional (3D) molecular models of proteins. A WWW interface has been developed to facilitate database searches and the export of data for sequence and structure analyses. As part of an international collaborative effort with the US and Japanese databases, the European HCV Database (euHCVdb) is mainly dedicated to HCV protein sequences, 3D structures and functional analyses.
Pelvic tilt posture is the key to ideal standing posture, yet no accurate quantitative measuremen... more Pelvic tilt posture is the key to ideal standing posture, yet no accurate quantitative measurements with standardized protocols have been implemented. The aim of the current study was to assess the calibration of a newly developed pelvic tilt sensor and to compare the repeatability using 2 protocols. Pelvic tilt was measured in a healthy woman with two different protocols and two repeated test were carried out for each protocol by a single tester. Repeatability testing for sagittal pelvic tilt was measured during neutral standing (NP), maximal anterior pelvic tilt (APT), and maximal posterior pelvic tilt (PPT). The newly developed pelvic tilt sensor was calibrated manually with a goniometer and indicated excellent correlation (r=0.99). NP, APT, and PPT in protocol 1 showed poor intra-class correlation (ICCs) compared to protocol 2 which showed high ICCs (r≥0.90) and low standard error of measurement (SEM). The excellent results obtained using the newly developed pelvic sensor in protocol 2 shows that it can be potentially used in clinical practice.
Network services are provided by means of dedicated service gateways, through which traffic flows... more Network services are provided by means of dedicated service gateways, through which traffic flows are directed. Existing work on service gateway placement has been primarily focused on minimizing the length of the routes through these gateways. Only limited attention has been paid to the effect these routes have on overall network performance. We propose a novel approach for the service placement problem, which takes into account traffic engineering considerations. Rather than trying to minimize the length of the traffic flow routes, we take advantage of these routes in order to enhance the overall network performance. We divide the problem into two sub-problems: finding the best location for each service gateway, and selecting the best service gateway for each flow. We propose efficient algorithms for both problems and study their performance. Our main contribution is showing that placement and selection of network services can be used as effective tools for traffic engineering.
In this paper, we propose a novel network design algorithm that yields the hierarchical optical p... more In this paper, we propose a novel network design algorithm that yields the hierarchical optical path network with dedicated wavelength path protection. A hierarchical optical path network provides two granularities in implementing dedicated protection in the optical layer, namely waveband path protection and wavelength path protection. The characteristics of both protection mechanisms are investigated. We develop the concept of the source-destination Cartesian product space to aggregate closely located traffic demands, which leads to a significant reduction in network resources needed. The proposed wavelength path protection algorithm achieves lower network costs than that possible with waveband protection when traffic volume is relatively small. On the other hand, in the large traffic demand area, both schemes offer almost the same cost, which makes the waveband protection scheme attractive because of its operational simplicity. Numerical results clarify that survivable hierarchical optical path network is more cost effective than the single layer optical path network with optical layer protection, irrespective of which protection scheme is utilized.
In dependable embedded systems, it is current practice to assign each application subsystem to a ... more In dependable embedded systems, it is current practice to assign each application subsystem to a dedicated processor. However, several activities aim at an integrated approach, allowing the deployment of multiple application subsystems on a single distributed computer system . The resulting large number of feasible allocations of tasks to processors makes it hard for the developer to determine an optimal solution, and therefore automatic allocation is desirable. This paper presents an allocation algorithm that takes advantage of the existence of replicated software and hardware components in dependable embedded systems and the resultant symmetric solutions in order to minimize the number of allocations taken into consideration.
Wireless sensor networks are evolving from dedicated application-specific platforms to integrated... more Wireless sensor networks are evolving from dedicated application-specific platforms to integrated infrastructure shared by multiple applications. Shared sensor networks offer inherent advantages in terms of flexibility and cost since they allow dynamic resource sharing and allocation among multiple applications. Such shared systems face the critical need for allocation of nodes to contending applications to enhance the overall Quality of Monitoring (QoM) under resource constraints.
RDF is a knowledge representation language dedicated to the annotation of resources within the fr... more RDF is a knowledge representation language dedicated to the annotation of resources within the framework of the semantic web. Among the query languages for querying an RDF knowledge base, some, such as SPARQL, are based on the formal semantics of RDF and the concept of semantic consequence, others, inspired by the work in databases, use regular expressions making it possible to search the paths in the graph associated with the knowledge base. In order to combine the expressivity of these two approaches, we define a mixed language, called PRDF (for "Paths RDF") in which the arcs of a graph can be labeled by regular expressions. We define the syntax and the semantics of these objects, and propose a correct and complete algorithm which, by a kind of homomorphism, calculates the semantic consequence between an RDF graph and a PRDF graph. This algorithm is the heart of query answering for the PSPARQL query language, the extension of the SPARQL query language which we propose and have implemented: a PSPARQL query allows to query an RDF knowledge base using graph patterns whose predicates are regular expressions.
The hepatitis C virus (HCV) genome shows remarkable sequence variability, leading to the classifi... more The hepatitis C virus (HCV) genome shows remarkable sequence variability, leading to the classification of at least six major genotypes, numerous subtypes and a myriad of quasispecies within a given host. A database allowing researchers to investigate the genetic and structural variability of all available HCV sequences is an essential tool for studies on the molecular virology and pathogenesis of hepatitis C as well as drug design and vaccine development. We describe here the European Hepatitis C Virus Database (euHCVdb, http://euhcvdb.ibcp.fr), a collection of computer-annotated sequences based on reference genomes. The annotations include genome mapping of sequences, use of recommended nomenclature, subtyping as well as three-dimensional (3D) molecular models of proteins. A WWW interface has been developed to facilitate database searches and the export of data for sequence and structure analyses. As part of an international collaborative effort with the US and Japanese databases, the European HCV Database (euHCVdb) is mainly dedicated to HCV protein sequences, 3D structures and functional analyses.
Pelvic tilt posture is the key to ideal standing posture, yet no accurate quantitative measuremen... more Pelvic tilt posture is the key to ideal standing posture, yet no accurate quantitative measurements with standardized protocols have been implemented. The aim of the current study was to assess the calibration of a newly developed pelvic tilt sensor and to compare the repeatability using 2 protocols. Pelvic tilt was measured in a healthy woman with two different protocols and two repeated test were carried out for each protocol by a single tester. Repeatability testing for sagittal pelvic tilt was measured during neutral standing (NP), maximal anterior pelvic tilt (APT), and maximal posterior pelvic tilt (PPT). The newly developed pelvic tilt sensor was calibrated manually with a goniometer and indicated excellent correlation (r=0.99). NP, APT, and PPT in protocol 1 showed poor intra-class correlation (ICCs) compared to protocol 2 which showed high ICCs (r≥0.90) and low standard error of measurement (SEM). The excellent results obtained using the newly developed pelvic sensor in protocol 2 shows that it can be potentially used in clinical practice.
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