International audienceHuman activity recognition plays an important role especially in medical applications. This paper proposes a formal approach to model such activities, taking into account possible variations in human behavior.... more
International audienceHuman activity recognition plays an important role especially in medical applications. This paper proposes a formal approach to model such activities, taking into account possible variations in human behavior. Starting from an activity description enriched with event occurrence probabilities, we translate it into a corresponding formal model based on discrete-time Markov chains (DTMCs). We use the PRISM framework and its model checking facilities to express and check interesting temporal logic properties (PCTL) concerning the dynamic evolution of activities. We illustrate our approach on the model of a serious game used by clinicians to monitor Alzheimer patients. We expect that such a modeling approach could provide new indications for interpreting patient performances. This paper addresses only the model definition and its suitability to check behavioral properties of interest. Indeed, this is mandatory before envisioning any clinical study.La reconnaissance ...
The presence of neurocognitive disorders (NCD) must be detected at an early stage of the disease progression and monitored by clinicians overtime, in order to provide early individualized interventions. Today, a reliable diagnosis... more
The presence of neurocognitive disorders (NCD) must be detected at an early stage of the disease progression and monitored by clinicians overtime, in order to provide early individualized interventions. Today, a reliable diagnosis requires a heavy set of neuropsychological tests, often coupled with biomarker evidence. There is growing interest in finding objective, fast to administer, and reliable behavioral markers that could complement classical clinical assessment and help detecting early changes in cognitive performance. Serious games have been proposed as promising tools to screen cognitive deficits in people with NCD [1]. In this study, we investigated the interest of employing a battery of mini‐games developed by CoBTeK lab to distinguish elderly patients with mild NCD from patients without cognitive decline.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Résumé: Modern software must continually adapt to changing operating contexts such as hardware/software platforms. This adaptation involves detection of context, mapping of context to a software configuration which is a set of appropriate... more
Résumé: Modern software must continually adapt to changing operating contexts such as hardware/software platforms. This adaptation involves detection of context, mapping of context to a software configuration which is a set of appropriate software components and ...
ABSTRACT
Research Interests:
This paper deals with dynamic adaption of software architecture in response to context changes. In the line of “models at run time”, we keep a model of the system and its context in parallel with the running system itself. We adopted an... more
This paper deals with dynamic adaption of software architecture in response to context changes. In the line of “models at run time”, we keep a model of the system and its context in parallel with the running system itself. We adopted an enriched Feature Model approach to express the variability of the architecture as well as of the context. A context change is transformed into a set of feature modifications (selection/deselection) that we validate against the feature model to yield a new suitable and valid architecture configuration. Then we update the model view of the configuration and the running system architecture accordingly. The paper focuses on the feature model reconfiguration step and details the algorithms and heuristics that implement our adaptation rules. The approach is illustrated with a simple example borrowed from the videosurveillance domain. The efficiency of the algorithm is evaluated on randomly generated feature models (from 60 to 1400 features). Our results sh...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
STARS,MCSOCActivity recognition is important for security and safety in many domains, such as surveillanceand health care. We propose to describe activities as a series of actions, triggered and driven by environmental events. We rely on... more
STARS,MCSOCActivity recognition is important for security and safety in many domains, such as surveillanceand health care. We propose to describe activities as a series of actions, triggered and driven by environmental events. We rely on synchronous automata to describe such activities. We chose the synchronousparadigm because it has a well-founded semantics and it ensures determinism and parallel composition.Moreover, we already developed tools that can be adapted to activity recognition. In this report we proposea new synchronous language to express synchronous automata, that relies on a formal semantics and that al-lows us to perform model-checking proofs, to compile activities into equation systems, and to automaticallygenerate the corresponding recognition code.La reconnaissance d’activité est devenue de plus en plus importante dans différents domainescomme la surveillance et la santé, pour sa sécurité et sûreté. Nous proposons de décrire les activités entant que série d’action...
Research Interests:
Résumé: Abstract. Many modern systems must run in continually changing contexts. For example, a computer vision system to detect vandalism in train stations must function during the day and at night. The software components for image... more
Résumé: Abstract. Many modern systems must run in continually changing contexts. For example, a computer vision system to detect vandalism in train stations must function during the day and at night. The software components for image acquisition and people detection ...
Research Interests:
École Doctorale des Sciences et Technologies de l’Information et
Research Interests:
Research Interests:
Abstract: When using a component framework developers need to respect the behavior implemented by the components. Static information about the component interface is not sufficient. Dynamic information such as the description of valid... more
Abstract: When using a component framework developers need to respect the behavior implemented by the components. Static information about the component interface is not sufficient. Dynamic information such as the description of valid sequences of operations is required. Instead of being in some external documentation, this information should be formally represented and embedded within the components themselves, so that it can be used by automatic tools. We propose a mathematical model and a formal language to describe the knowledge about behavior. We rely on a hierarchical model of deterministic finite state-machines. The communication between the machines follows the Synchronous Paradigm. We favor a structural approach allowing incremental simulation, automatic verification, code generation, and run-time checks. Associated tools may ensure correct and safe reuse of the components. We focus on extension of components through inheritance (in the sense of sub-typing), owing to the no...
Research Interests:
Research Interests:
Activity recognition is important for security and safety in many domains, such as surveillance and health care. We propose to describe activities as a series of actions, triggered and driven by environmental events. We rely on... more
Activity recognition is important for security and safety in many domains, such as surveillance and health care. We propose to describe activities as a series of actions, triggered and driven by environmental events. We rely on synchronous automata to describe such activities. We chose the synchronous paradigm because it has a well-founded semantics and it ensures determinism and parallel composition. Moreover, we already developed tools that can be adapted to activity recognition. In this report we propose a new synchronous language to express synchronous automata, that relies on a formal semantics and that al- lows us to perform model-checking proofs, to compile activities into equation systems, and to automatically generate the corresponding recognition code.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Human activity recognition plays an important role especially in medical applications. This paper proposes a formal approach to model such activities, taking into account possible variations in human behavior. Starting from an activity... more
Human activity recognition plays an important role especially in medical applications. This paper proposes a formal approach to model such activities, taking into account possible variations in human behavior. Starting from an activity description enriched with event occurrence probabilities, we translate it into a corresponding formal model based on discrete-time Markov chains (DTMCs). We use the PRISM framework and its model checking facilities to express and check interesting temporal logic properties concerning the dynamic evolution of activities. We illustrate our approach with the models of several serious games used by clinicians to monitor Alzheimer patients. We expect that such a modeling approach could provide new indications for interpreting patient performances. This paper addresses the definition of patient's models for three serious games and the suitability of this approach to check behavioral properties of medical interest. Indeed, this is a mandatory first step ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Many important and critical applications such as surveillance or healthcare require some form of (human) activity recognition. Activities are usually represented by a series of actions driven and triggered by events. Recognition systems... more
Many important and critical applications such as surveillance or healthcare require some form of (human) activity recognition. Activities are usually represented by a series of actions driven and triggered by events. Recognition systems have to be real time, reactive, correct, complete, and dependable. These stringent requirements justify the use of formal methods to describe, analyze, verify, and generate effective recognition systems. Due to the large number of possible application domains, the researchers aim at building a generic recognition system. They choose the synchronous approach because it has a well-founded semantics and it ensures determinism and safe parallel composition. They propose a new language to represent activities as synchronous automata and they supply it with two complementary formal semantics. First a behavioral semantics gives a reference definition of program behavior using rewriting rules. Second, an equational semantics describes the behavior in a const...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Computer Science, Software Engineering, Systems Engineering, Software Product Lines, Automated reasoning, and 15 moreAdaptive Systems, Model Driven Development, Edge Detection, Quality of Service, Formal Specification, Dynamic Software Adaptation, Adaptive System, Software Requirement Specification, Feature Models, Software Product Line, Frequency Modulation, Software Tool, Feature Model, Consistency Checking, and feature modeling
Research Interests:
Research Interests:
Research Interests:
When using a component framework, developers need to respect the behavior implemented by the components. Static information about the component interface is not sufficient. Dynamic information such as the description of valid sequences of... more
When using a component framework, developers need to respect the behavior implemented by the components. Static information about the component interface is not sufficient. Dynamic information such as the description of valid sequences of operations is required. In this paper we propose a mathematical model obeying the Synchronous hypothesis and a formal language to describe the knowledge about behavior. We focus on extension of components, owing to the notion of behavioral substitutability. A formal semantics for the language is defined and a compositionality result allows us to get modular model-checking facilities. From the language and the model, we can draw practical design rules that are sufficient to preserve behavioral substitutability. Associated tools may ensure correct (re)use of components, as well as automatic simulation and verification, code generation, and runtime checks.
This paper summarizes the experience of teaching object-oriented modeling and UML for more than a decade to various audiences (academic or corporate, software developers or not). We present the characteristics of the audiences. We... more
This paper summarizes the experience of teaching object-oriented modeling and UML for more than a decade to various audiences (academic or corporate, software developers or not). We present the characteristics of the audiences. We investigate which modeling concepts are well accepted and which are not. We identify several general problems: attendee background, object-oriented language as a prerequisite, limitations of tools, methodological issues, impact of company organizations. We propose (partial) solutions and a list of pragmatic advices.
Research Interests:
The pharmacokinetics of mezlocillin after intravenous infusion of 5 g over 30 minutes was compared in 15 patients divided into 3 groups. Group I patients had normal renal function, group II patients had moderate chronic renal impairment... more
The pharmacokinetics of mezlocillin after intravenous infusion of 5 g over 30 minutes was compared in 15 patients divided into 3 groups. Group I patients had normal renal function, group II patients had moderate chronic renal impairment and group III patients were under haemodialysis. Plasma mezlocillin levels were measured by the microbiological method. Plasma kinetic values were calculated from a linear two-compartment model, using global estimation of macroconstants by the non-linear least square method. The elimination half-life was 1.19 +/- 0.107 h in group I patients 1.98 +/- 0.19 h in group II patients and 2.34 +/- 0.11 h in group III patients. Renal impairment did not significantly alter the apparent volume of distribution but influenced the total plasma clearance which was 139 +/- 9 ml/min, 87 +/- 9 ml/min and 61 +/- 8 ml/min in groups I, II and III patients respectively. There was a slight decrease of V1 (central compartment) and a noticeable increase of V2 (peripheral compartment), depending on the degree of renal impairment. The total volume of distribution (V1 + V2) remained relatively constant between 12 and 14 litres. Homogeneous results were obtained in each group of patients, thus confirming the regularity of the mezlocillin kinetic model at the dose administered. This should enable dosage adjustment according to renal function, as assessed by laboratory criteria.
Research Interests: Kinetics, Kidney diseases, Humans, Female, Male, and 5 moreAged, Middle Aged, Adult, Renal Dialysis, and Penicillins
An analytic method, sensitive to 5 ng/ml and specific, has been set up for the determination of unchanged 5-fluorouracil in human plasma, using gas chromatography--mass spectrometry. Its applications to the pharmacokinetic study of... more
An analytic method, sensitive to 5 ng/ml and specific, has been set up for the determination of unchanged 5-fluorouracil in human plasma, using gas chromatography--mass spectrometry. Its applications to the pharmacokinetic study of unchanged 5-Fluorouracil in man following an intravenous bolus, 8 hours infusion and oral administration confirmed the non-linearity of the kinetic model. (The clearances obtained with an infusion--from 5 to 60 1/min--are 10 to 60 times higher than the ones observed with a bolus--from 0.5 to 1.4 1/min.) The bioavailability of the oral form seems to be about 60 per cent and the absorption appears to be very fast. A attempt to search a mathematical non-linear model of the 5-Fluorouracil kinetics, using computer simulation, is presented.
Research Interests:
This study involves 3 children ranging from 10 to 13 years and an eight-month-old infant who received Cis-DDP (30-100 mg/m2) every fourth week by means of a short-term infusion (20-35 minutes). Platinum levels in plasma and urine were... more
This study involves 3 children ranging from 10 to 13 years and an eight-month-old infant who received Cis-DDP (30-100 mg/m2) every fourth week by means of a short-term infusion (20-35 minutes). Platinum levels in plasma and urine were determined by flameless atomic absorption spectrophotometry. The decrease in total plasma platinum is triphasic, consistent with the distribution expected for a 3 compartment model. In the elimination phase, the half-life values are high and vary between 149 and 541 hours. The total plasma clearances are extremely low and range from 0.027 to 0.187 litre/hour. The urinary excretion of platinum during the first 5 and 7 days respectively, in two children following administration of Cis-DDP results in large platinum concentrations (40-71 mg/litre) in the first urine excreted from each child. The cumulative urinary platinum excretion in the first twelve hours is high i. e. 27.2 to 32.5% of the administered dose but them it does not exceed 50% even after 5 days. These results confirm that after a short-term infusion of Cis-DDP in a single dose, the kidneys are suddenly subjected to platinum in high concentrations. In order to minimize the nephrotoxicity of this platinum complex, while maintaining sufficient plasma levels to ensure its anti-neoplastic activity, we recommend a schedule consisting of fractionated doses.
Research Interests:
The use of pharmacokinetic studies for individual dose regimen adjustments in anticancer therapy is considered. The example of methotrexate in the treatment of head and neck tumors demonstrates the validity of this approach. Moreover, the... more
The use of pharmacokinetic studies for individual dose regimen adjustments in anticancer therapy is considered. The example of methotrexate in the treatment of head and neck tumors demonstrates the validity of this approach. Moreover, the importance of biotransformations of this antimetabolite is confirmed using a high pressure liquid chromatography assay. The example of 5-FU outlines the analytical and mathematical difficulties rendering this approach unlikely for routine use. Some preliminary relations between pharmacokinetic parameters (plasma clearance) and clinical response are presented. The determination of the main plasma metabolic 5-6 dihydro 5-FU by GC/MS and its possible role in the nonlinear pharmacokinetics of the drug in therapeutic failure are discussed.