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  • Mémoires en Sciences de l'Information et de la Communication

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  • Publication . Part of book or chapter of book . 2018
    Closed Access
    Authors: 
    Thierry Billard; François Liger; Mathieu Verdurand;
    Publisher: Elsevier
    Country: France

    Abstract The serotonergic system plays a key modulatory role in the brain. This system is critical in many drug developments for brain disorders via interactions with the 14 subtypes of 5-HT receptors or through reuptake blockade. Positron emission tomography (PET) is an efficient tool for in vivo studies of physiological and pathological processes. Because of its pertinent radiochemical properties, fluorine-18 is one of the most used radioisotopes in PET imaging. This chapter will propose an overview of the 18F-radioligands targeting serotonin receptors, which have been developed over the last few years. Both radiosyntheses and pharmacological properties of these radiotracers will be described, with a specific emphasis on their potential medical applications.

  • Publication . Other literature type . Conference object . 2019
    Open Access
    Authors: 
    Shivani Rajendra Teli; Stanislav Zvanovec; Zabih Ghassemlooy;
    Countries: United Kingdom, France
    Project: EC | VisIoN (764461)

    International audience; In this paper, we study the effect of smartphone camera exposure on the performance of optical camera communications (OCC) link. The exposure parameters of image sensor sensitivity (ISO), aperture and shutter speed are included. A static OCC link with a 8 × 8 red, green and blue (RGB) LED array employed as the transmitter and a smartphone camera as the receiver is demonstrated to verify the study. Signal-to-noise ratio (SNR) analysis at different ISO values, the effect of aperture and shutter speed on communication link quality is performed. While SNRs of 20.6 dB and 16.9 dB are measured at 1 m and 2 m transmission distance, respectively for a ISO value of 100, they are decreased to 17.4 dB and 13.32 dB for a ISO of 800. The bit error rate (BER) of a 1 m long OCC link with a camera's shutter speed of 1/6000 s is 1.3 × 10 −3 (i.e., below the forward error correction BER limit of 3.8 × 10 −3) and is dropped to 0.0125 at a shutter speed of 1/20 s. This study provides insight of the basic smartphone settings and the exposure adjustment for further complex OCC links.

  • Publication . Article . Part of book or chapter of book . 2020
    Open Access English
    Authors: 
    Hassen Nigatu; Yimesker Yihun;
    Publisher: HAL CCSD
    Country: France

    International audience; This study presents an algebraic method to detect, count, and identify concomitant motions of parallel robots at the velocity level. The pose and orientation of moving platform of parallel manipulators (PMs) with f-DOF could be commonly described by f possible motion variables on the instantaneous motion space (IMS) and (6 − f) restriction motion variables on the instantaneous restriction space (IRS). However, in some situations, PMs moving platform may accompanied by a concomitant (parasitic) motions along the direction of restriction space. Therefore, the commonly understood one-to-one correspondence between joint space and task space mobility of non-redundant PMs would be compromised. This phenomenon occurred due to the fact that the alignment of screws can change the reciprocal screws while the given screw systems are still maintained. To demonstrate the proposed method, an amplitude-based concomitant motion comparison is performed on two widely utilized lower-mobility parallel mechanisms, 3RPS and 3PRS. The result has shown that for the selected mechanisms, concomitant motion is identical regardless of their difference in joint arrangements in each limbs.

  • Publication . Other literature type . Part of book or chapter of book . Conference object . 2019
    Closed Access
    Authors: 
    Aishatu Shuaibu; Salihu Ibrahim Dasuki; Muhammadou M. O. Kah;
    Publisher: Springer International Publishing

    Part 1: Communities, ICT-Enabled Networks, and Development; International audience; This study is aimed at understanding the implementation of Information Communication Technology (ICT) tool to electoral process and its challenges in Nigeria using actor-network theory (ANT) as a lens. Moment of translation of ANT was applied to gain an insight of the phenomenon. Empirical data was used for the analysis in the context of social behavior between human and non-human actors following inductive research approach. Case study methodology was carried out at Independent National Electoral Commission (INEC). The methods of data collection were through interview, participant observation and reviewing organizational documents. Challenges of the Smart Card Reader (SCR) in Nigeria’s electoral process are highlighted. Results of the study indicated that the challenges in implementation of the SCR emanated from the heterogeneous actors “human and non-human”, which lack synchrony during the process. Apart from the success of the card reader during accreditation, there was inadequate manpower training by INEC body and insufficient ICT infrastructure that weakened the ANT process.

  • Open Access English
    Authors: 
    Martin, Adrian; Coolsaet, Brendan; Corbera, Esteve; Dawson, Neil; Fisher, Janet; Franks, Phil; Mertz, Ole; Pascual, Unai; Rasmussen, Laura,; Ryan, Casey;
    Publisher: HAL CCSD
    Countries: France, United Kingdom

    Land use intensification is widely considered to be an essential strategy for achieving global goals to eliminate poverty and to avoid damaging losses of ecosystem services. This chapter investigates whether current land use intensification activities are achieving these twin goals. To do so, it reviews a body of academic literature that reports on case studies in which both social and ecological outcomes of intensification are reported. There are two main findings. First, there are relatively few cases in which land use intensification is clearly succeeding in these twinned objectives. There are many more cases in which, for example, short-term income or productivity gains from land use intensification are resulting in long-term diminution of biodiversity and ecosystem services. Studies with longer-term perspectives are already seeing how such trade-offs are leading to negative feedbacks for human wellbeing, especially for marginalised social groups. Secondly, we learn most from those studies that a) go beyond measuring production and income to measure multiple dimensions of wellbeing and ecosystem services, b) monitor dynamics of outcomes across longer time periods and across landscapes and c) disaggregate outcome measures to identify outcomes for different social groups.

  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Barthe, Gilles; Dupressoir, François; Faust, Sebastian; Grégoire, Benjamin; Standaert, François-Xavier; Strub, Pierre-Yves; 36th Annual International Conference on the Theory and Applications of cryptographic Techniques (EUROCRYPT 2017);
    Publisher: Springer
    Countries: France, France, Belgium
    Project: EC | CRASH (280141), EC | AMAROUT-II (291803)

    International audience; In this paper, we provide a necessary clarification of the good security properties that can be obtained from parallel implementations of masking schemes. For this purpose, we first argue that (i) the probing model is not straightforward to interpret, since it more naturally captures the intuitions of serial implementations, and (ii) the noisy leakage model is not always convenient, e.g. when combined with formal methods for the verification of cryptographic implementations. Therefore we introduce a new model, the bounded moment model, that formalizes a weaker notion of security order frequently used in the side-channel literature. Interestingly , we prove that probing security for a serial implementation implies bounded moment security for its parallel counterpart. This result therefore enables an accurate understanding of the links between formal security analyses of masking schemes and experimental security evaluations based on the estimation of statistical moments Besides its consolidating nature, our work also brings useful technical contributions. First, we describe and analyze refreshing and multiplication algorithms that are well suited for parallel implementations and improve security against multivariate side-channel attacks. Second, we show that simple refreshing algorithms (with linear complexity) that are not secure in the continuous probing model are secure in the continuous bounded moment model. Eventually, we discuss the independent leakage assumption required for masking to deliver its security promises, and its specificities related to the serial or parallel nature of an implementation.

  • Publication . Other literature type . Part of book or chapter of book . 2019
    Closed Access English
    Authors: 
    Romain Quentin; Oluwole Awosika; Leonardo G. Cohen;
    Publisher: HAL CCSD

    Abstract The frontal lobe plays a crucial role in human motor behavior. It is one of the last areas of the brain to mature, especially the prefrontal regions. After a brief historical perspective on the perceived dichotomy between the view of the brain as a static organ and that of a plastic, constantly changing structure, we discuss the stability/plasticity dilemma including examples of documented cortical reorganization taking place at multiple spatial and temporal scales. We pose that while plasticity is needed for motor learning, stability of the system is necessary for storage and maintenance of memorized skills. We discuss how this plasticity/stability dilemma is resolved along the life span and after a brain injury. We then examine the main challenges that clinicians have to overcome to promote recovery of function in patients with brain lesions, including attempts to use neurostimulation techniques as adjuvant to training-based customary neurorehabilitation.

  • Closed Access English
    Authors: 
    Jordan Phillipson; Gordon S. Blair; Peter A. Henrys;
    Publisher: HAL CCSD
    Country: France

    International audience; The use of land cover mappings built using remotely sensed imagery data has become increasingly popular in recent years. However, these mappings are ultimately only models. Consequently, it is vital for one to be able to assess and verify the quality of a mapping and quantify uncertainty for any estimates that are derived from them in a reliable manner.For this, the use of validation sets and error matrices is a long standard practice in land cover mapping applications. In this paper, we review current state of the art methods for quantifying uncertainty for estimates obtained from error matrices in a land cover mapping context. Specifically, we review methods based on their transparency, generalisability, suitability when stratified sampling and suitability in low count situations. This is done with the use of a third-party case study to act as a motivating and demonstrative example throughout the paper.The main finding of this paper is there is a major issue of transparency for methods that quantify uncertainty in terms of confidence intervals (frequentist methods). This is primarily because of the difficulty of analysing nominal coverages in common situations. Effectively, this leaves one without the necessary tools to know when a frequentist method is reliable in all but a few niche situations. The paper then discusses how a Bayesian approach may be better suited as a default method for uncertainty quantification when judged by our criteria.

  • Publication . Part of book or chapter of book . Preprint . Article . 2020
    Open Access English
    Authors: 
    Florian Bridoux; Maximilien Gadouleau; Guillaume Theyssier;
    Publisher: HAL CCSD
    Country: France

    Automata networks are mappings of the form \(f: Q^Z \rightarrow Q^Z\), where Q is a finite alphabet and Z is a set of entities; they generalise Cellular Automata and Boolean networks. An update schedule dictates when each entity updates its state according to its local function \(f_i: Q^Z \rightarrow Q\). One major question is to study the behaviour of a given automata networks under different update schedules. In this paper, we study automata networks that are invariant under many different update schedules. This gives rise to two definitions, locally commutative and globally commutative networks. We investigate the relation between commutativity and different forms of locality of update functions; one main conclusion is that globally commutative networks have strong dynamical properties, while locally commutative networks are much less constrained. We also give a complete classification of all globally commutative Boolean networks.

  • Closed Access English
    Authors: 
    Jean-Paul Carrière; Stuart Farthing;
    Publisher: HAL CCSD
    Country: France

    In this research, we investigated the environmental as well as social impacts of the regeneration of urban riverbanks and waterfronts, localities previously occupied by port-industrial activities established during the twentieth century or earlier, but more recently abandoned and occupied by informal housing and wasteland or brownfield land. The urban plans and strategies of metropolises as well as of medium-sized cities have become increasingly underpinned by the “paradigm of attractiveness,” in a context of globalization and competition between cities at an international scale. In order to become more attractive for investment, mainly foreign direct investment, cities need to improve their image and their international ranking. The recycling of the abandoned wasteland in these areas has become a policy priority. Under the banner of sustainable development, strategic plans in many cities throughout the world have thus promoted flagship projects for the regeneration of these waterfront areas, incorporating new environmental amenities.

Advanced search in
Research products
arrow_drop_down
Searching FieldsTerms
Any field
arrow_drop_down
includes
arrow_drop_down
Include:
2,770 Research products, page 1 of 277
  • Publication . Part of book or chapter of book . 2018
    Closed Access
    Authors: 
    Thierry Billard; François Liger; Mathieu Verdurand;
    Publisher: Elsevier
    Country: France

    Abstract The serotonergic system plays a key modulatory role in the brain. This system is critical in many drug developments for brain disorders via interactions with the 14 subtypes of 5-HT receptors or through reuptake blockade. Positron emission tomography (PET) is an efficient tool for in vivo studies of physiological and pathological processes. Because of its pertinent radiochemical properties, fluorine-18 is one of the most used radioisotopes in PET imaging. This chapter will propose an overview of the 18F-radioligands targeting serotonin receptors, which have been developed over the last few years. Both radiosyntheses and pharmacological properties of these radiotracers will be described, with a specific emphasis on their potential medical applications.

  • Publication . Other literature type . Conference object . 2019
    Open Access
    Authors: 
    Shivani Rajendra Teli; Stanislav Zvanovec; Zabih Ghassemlooy;
    Countries: United Kingdom, France
    Project: EC | VisIoN (764461)

    International audience; In this paper, we study the effect of smartphone camera exposure on the performance of optical camera communications (OCC) link. The exposure parameters of image sensor sensitivity (ISO), aperture and shutter speed are included. A static OCC link with a 8 × 8 red, green and blue (RGB) LED array employed as the transmitter and a smartphone camera as the receiver is demonstrated to verify the study. Signal-to-noise ratio (SNR) analysis at different ISO values, the effect of aperture and shutter speed on communication link quality is performed. While SNRs of 20.6 dB and 16.9 dB are measured at 1 m and 2 m transmission distance, respectively for a ISO value of 100, they are decreased to 17.4 dB and 13.32 dB for a ISO of 800. The bit error rate (BER) of a 1 m long OCC link with a camera's shutter speed of 1/6000 s is 1.3 × 10 −3 (i.e., below the forward error correction BER limit of 3.8 × 10 −3) and is dropped to 0.0125 at a shutter speed of 1/20 s. This study provides insight of the basic smartphone settings and the exposure adjustment for further complex OCC links.

  • Publication . Article . Part of book or chapter of book . 2020
    Open Access English
    Authors: 
    Hassen Nigatu; Yimesker Yihun;
    Publisher: HAL CCSD
    Country: France

    International audience; This study presents an algebraic method to detect, count, and identify concomitant motions of parallel robots at the velocity level. The pose and orientation of moving platform of parallel manipulators (PMs) with f-DOF could be commonly described by f possible motion variables on the instantaneous motion space (IMS) and (6 − f) restriction motion variables on the instantaneous restriction space (IRS). However, in some situations, PMs moving platform may accompanied by a concomitant (parasitic) motions along the direction of restriction space. Therefore, the commonly understood one-to-one correspondence between joint space and task space mobility of non-redundant PMs would be compromised. This phenomenon occurred due to the fact that the alignment of screws can change the reciprocal screws while the given screw systems are still maintained. To demonstrate the proposed method, an amplitude-based concomitant motion comparison is performed on two widely utilized lower-mobility parallel mechanisms, 3RPS and 3PRS. The result has shown that for the selected mechanisms, concomitant motion is identical regardless of their difference in joint arrangements in each limbs.

  • Publication . Other literature type . Part of book or chapter of book . Conference object . 2019
    Closed Access
    Authors: 
    Aishatu Shuaibu; Salihu Ibrahim Dasuki; Muhammadou M. O. Kah;
    Publisher: Springer International Publishing

    Part 1: Communities, ICT-Enabled Networks, and Development; International audience; This study is aimed at understanding the implementation of Information Communication Technology (ICT) tool to electoral process and its challenges in Nigeria using actor-network theory (ANT) as a lens. Moment of translation of ANT was applied to gain an insight of the phenomenon. Empirical data was used for the analysis in the context of social behavior between human and non-human actors following inductive research approach. Case study methodology was carried out at Independent National Electoral Commission (INEC). The methods of data collection were through interview, participant observation and reviewing organizational documents. Challenges of the Smart Card Reader (SCR) in Nigeria’s electoral process are highlighted. Results of the study indicated that the challenges in implementation of the SCR emanated from the heterogeneous actors “human and non-human”, which lack synchrony during the process. Apart from the success of the card reader during accreditation, there was inadequate manpower training by INEC body and insufficient ICT infrastructure that weakened the ANT process.

  • Open Access English
    Authors: 
    Martin, Adrian; Coolsaet, Brendan; Corbera, Esteve; Dawson, Neil; Fisher, Janet; Franks, Phil; Mertz, Ole; Pascual, Unai; Rasmussen, Laura,; Ryan, Casey;
    Publisher: HAL CCSD
    Countries: France, United Kingdom

    Land use intensification is widely considered to be an essential strategy for achieving global goals to eliminate poverty and to avoid damaging losses of ecosystem services. This chapter investigates whether current land use intensification activities are achieving these twin goals. To do so, it reviews a body of academic literature that reports on case studies in which both social and ecological outcomes of intensification are reported. There are two main findings. First, there are relatively few cases in which land use intensification is clearly succeeding in these twinned objectives. There are many more cases in which, for example, short-term income or productivity gains from land use intensification are resulting in long-term diminution of biodiversity and ecosystem services. Studies with longer-term perspectives are already seeing how such trade-offs are leading to negative feedbacks for human wellbeing, especially for marginalised social groups. Secondly, we learn most from those studies that a) go beyond measuring production and income to measure multiple dimensions of wellbeing and ecosystem services, b) monitor dynamics of outcomes across longer time periods and across landscapes and c) disaggregate outcome measures to identify outcomes for different social groups.

  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Barthe, Gilles; Dupressoir, François; Faust, Sebastian; Grégoire, Benjamin; Standaert, François-Xavier; Strub, Pierre-Yves; 36th Annual International Conference on the Theory and Applications of cryptographic Techniques (EUROCRYPT 2017);
    Publisher: Springer
    Countries: France, France, Belgium
    Project: EC | CRASH (280141), EC | AMAROUT-II (291803)

    International audience; In this paper, we provide a necessary clarification of the good security properties that can be obtained from parallel implementations of masking schemes. For this purpose, we first argue that (i) the probing model is not straightforward to interpret, since it more naturally captures the intuitions of serial implementations, and (ii) the noisy leakage model is not always convenient, e.g. when combined with formal methods for the verification of cryptographic implementations. Therefore we introduce a new model, the bounded moment model, that formalizes a weaker notion of security order frequently used in the side-channel literature. Interestingly , we prove that probing security for a serial implementation implies bounded moment security for its parallel counterpart. This result therefore enables an accurate understanding of the links between formal security analyses of masking schemes and experimental security evaluations based on the estimation of statistical moments Besides its consolidating nature, our work also brings useful technical contributions. First, we describe and analyze refreshing and multiplication algorithms that are well suited for parallel implementations and improve security against multivariate side-channel attacks. Second, we show that simple refreshing algorithms (with linear complexity) that are not secure in the continuous probing model are secure in the continuous bounded moment model. Eventually, we discuss the independent leakage assumption required for masking to deliver its security promises, and its specificities related to the serial or parallel nature of an implementation.

  • Publication . Other literature type . Part of book or chapter of book . 2019
    Closed Access English
    Authors: 
    Romain Quentin; Oluwole Awosika; Leonardo G. Cohen;
    Publisher: HAL CCSD

    Abstract The frontal lobe plays a crucial role in human motor behavior. It is one of the last areas of the brain to mature, especially the prefrontal regions. After a brief historical perspective on the perceived dichotomy between the view of the brain as a static organ and that of a plastic, constantly changing structure, we discuss the stability/plasticity dilemma including examples of documented cortical reorganization taking place at multiple spatial and temporal scales. We pose that while plasticity is needed for motor learning, stability of the system is necessary for storage and maintenance of memorized skills. We discuss how this plasticity/stability dilemma is resolved along the life span and after a brain injury. We then examine the main challenges that clinicians have to overcome to promote recovery of function in patients with brain lesions, including attempts to use neurostimulation techniques as adjuvant to training-based customary neurorehabilitation.

  • Closed Access English
    Authors: 
    Jordan Phillipson; Gordon S. Blair; Peter A. Henrys;
    Publisher: HAL CCSD
    Country: France

    International audience; The use of land cover mappings built using remotely sensed imagery data has become increasingly popular in recent years. However, these mappings are ultimately only models. Consequently, it is vital for one to be able to assess and verify the quality of a mapping and quantify uncertainty for any estimates that are derived from them in a reliable manner.For this, the use of validation sets and error matrices is a long standard practice in land cover mapping applications. In this paper, we review current state of the art methods for quantifying uncertainty for estimates obtained from error matrices in a land cover mapping context. Specifically, we review methods based on their transparency, generalisability, suitability when stratified sampling and suitability in low count situations. This is done with the use of a third-party case study to act as a motivating and demonstrative example throughout the paper.The main finding of this paper is there is a major issue of transparency for methods that quantify uncertainty in terms of confidence intervals (frequentist methods). This is primarily because of the difficulty of analysing nominal coverages in common situations. Effectively, this leaves one without the necessary tools to know when a frequentist method is reliable in all but a few niche situations. The paper then discusses how a Bayesian approach may be better suited as a default method for uncertainty quantification when judged by our criteria.

  • Publication . Part of book or chapter of book . Preprint . Article . 2020
    Open Access English
    Authors: 
    Florian Bridoux; Maximilien Gadouleau; Guillaume Theyssier;
    Publisher: HAL CCSD
    Country: France

    Automata networks are mappings of the form \(f: Q^Z \rightarrow Q^Z\), where Q is a finite alphabet and Z is a set of entities; they generalise Cellular Automata and Boolean networks. An update schedule dictates when each entity updates its state according to its local function \(f_i: Q^Z \rightarrow Q\). One major question is to study the behaviour of a given automata networks under different update schedules. In this paper, we study automata networks that are invariant under many different update schedules. This gives rise to two definitions, locally commutative and globally commutative networks. We investigate the relation between commutativity and different forms of locality of update functions; one main conclusion is that globally commutative networks have strong dynamical properties, while locally commutative networks are much less constrained. We also give a complete classification of all globally commutative Boolean networks.

  • Closed Access English
    Authors: 
    Jean-Paul Carrière; Stuart Farthing;
    Publisher: HAL CCSD
    Country: France

    In this research, we investigated the environmental as well as social impacts of the regeneration of urban riverbanks and waterfronts, localities previously occupied by port-industrial activities established during the twentieth century or earlier, but more recently abandoned and occupied by informal housing and wasteland or brownfield land. The urban plans and strategies of metropolises as well as of medium-sized cities have become increasingly underpinned by the “paradigm of attractiveness,” in a context of globalization and competition between cities at an international scale. In order to become more attractive for investment, mainly foreign direct investment, cities need to improve their image and their international ranking. The recycling of the abandoned wasteland in these areas has become a policy priority. Under the banner of sustainable development, strategic plans in many cities throughout the world have thus promoted flagship projects for the regeneration of these waterfront areas, incorporating new environmental amenities.

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