Verifying parallel programs with dynamic communication structures

We address the verification problem of networks of communicating pushdown systems modeling communicating parallel programs with procedure calls. Processes in such networks can read the control state of the other processes according to a given communication structure (specifying the observability rights between processes). The reachability problem of such models is undecidable in general. First, we define a class of networks that effectively preserves recognizability (hence, its reachability problem is decidable). Then, we consider networks where the communication structure can change dynamically during the execution according to a phase graph. The reachability problem for these dynamic networks being undecidable in general, we define a subclass for which it becomes decidable. Then, we consider reachability when the switches in the communication structures are bounded. We show that this problem is undecidable even for one switch. We define a natural class of models for which this problem is decidable. This class can be used in the definition of an efficient semi-decision procedure for the analysis of the general model of dynamic networks. Our techniques allowed to find bugs in two versions of a Windows NT Bluetooth driver.     

Automatic speech recognition system for Tunisian dialect

Although Modern Standard Arabic is taught in schools and used in written communication and TV/radio broadcasts, all informal communication is typically carried out in dialectal Arabic. In this work, we focus on the design of speech tools and resources required for the development of an Automatic Speech Recognition system for the Tunisian dialect. The development of such a system faces the challenges of the lack of annotated resources and tools, apart from the lack of standardization at all linguistic levels (phonological, morphological, syntactic and lexical) together with the mispronunciation dictionary needed for ASR development. In this paper, we present a historical overview of the Tunisian dialect and its linguistic characteristics. We also describe and evaluate our rule-based phonetic tool. Next, we go deeper into the details of Tunisian dialect corpus creation. This corpus is finally approved and used to build the first ASR system for Tunisian dialect with a Word Error Rate of 22.6%.     

An ontology for representing financial headline news

This paper presents the development of an ontology to represent financial headline news. This ontology is developed using the On-To-Knowledge methodology where the focus is on the design steps of the Knowledge Meta Process. This development is part of an ongoing project which aims to design a virtual stock market simulator based on multi-agent systems. The proposed ontology has 31 concepts and includes 201 attributes. The testing results conducted on reliable headline news show that 99% of these headline news can be properly represented by the attributes of the right category in the ontology. Unreliable headline news characterized by news having uncertainties, incompleteness, ill-definition, or imprecision cannot be represented by the proposed ontology. Approaches for representing these unreliable headline news are discussed.     

A Fuzzy Collaborative Assessment Methodology for Partner Trust Evaluation

Trust level assessment within collaborative networks is an interesting issue in the partner evaluation and partner selection literature. This paper proposes a fuzzy collaborative assessment methodology for partner trust evaluation within horizontal collaborative networks. The proposed approach concerns a group evaluation context where a decision‐making comity associated with a manufacturer needs to evaluate its company's partners for their ranking purposes. Different expertise levels are attributed to the comity members. In this paper, trust level is evaluated based on information‐sharing attributes considered in the literature as critical influencing factors. Different weights are associated with these attributes with respect to their corresponding influence on trust. The semantic fuzzy partitioning method is considered for the collaborative trust assessment based on unbalanced linguistic term sets representing information‐sharing attributes. The developed approach is applied to a real case showing its effectiveness and its objectivity.     

Perfect tracking of ZMP trajectory for humanoid locomotion using repetitive control

Journal of Mechanical Science and Technology - In this paper, the tracking of the zero moment point (ZMP) trajectory for humanoid locomotion is addressed. For that, a combination of a repetitive...     

Convection behavior analysis of CMOS MEMS thermal accelerometers using FEM and Hardee’s model

This paper presents convection behavior investigation of CMOS MEMS convective accelerometers using both analytical and FEM techniques. In a first part, a newly developed accelerometer 3D model is used in FEM simulations to model convection behavior as a function of design geometry and temperature. Using various sizes of two different cover shapes, sensitivity reading and its maximum position in cavity are found to be largely affected by both cover size and shape. In addition, a sensor with cavity width of 600 μm produces sensitivity saturation starting at a cavity depth of 200 μm, for both cover shapes. Using FEM data and curve fitting, differential temperature is claimed to be linearly linked to the effective heater temperature to the power of 1.7. Using the same cavity design and from computed heating efficiency values, we found that a 60 μm width heater offers the best efficiency. This cavity and heater designs give an optimal detector position of 120 μm from heater center along the sensitive axis. Moreover, dual axis accelerometers are found to be more power efficient than single axis ones. In the second part, we present Hardee’s spherical model and investigate its possible application on convective accelerometers. It is shown that inner and outer isotherms deformation, caused by accelerometer design and convection process, should be modeled by including sensor geometry parameters in the derived governing equations. Moreover, Hardee’s biasing temperature relation has to be revised if it is to be used for convective accelerometers.     

Mesoscopic approach for steady‐state free convection in a diamond array

The purpose of the present paper is testing an in‐house efficiency algorithm based on lattice Boltzmann method (LBM) and using it to resolve the obtained coupled nondimensional governing equations to analyze two‐dimensional free convection inside a cold outer cavity subjected to a heated cylindrical diamond array. Steady state or oscillatory results are obtained using the Bhatnagar‐Gross‐Krook collision model associated to the thermal LBM. Both the velocity and temperature fields are solved using the D2Q9 models. With different Rayleigh numbers (Ra), the tested free convection can either achieve to steady state or oscillatory. We extended our in house Fortran 90 code using curved boundary conditions and implemented them into a cavity with a diamond array. The numerical simulations were done using distinct Ra (10⁶ and 10 ⁷) and distances between the four neighboring circular cylinders aligned in a diamond array. The effects of several physical parameters, including Ra and position of the hot body array on flow and heat transfer characteristics are investigated. The obtained results are highlighted in the form of streamlines, isotherms, and velocities plots. We show in this paper the stability and the efficiency of the LBM to deal with a complex geometry and its ability to reach suitable convergence criteria for high Ra (10 ⁶ and 10 ⁷). The numerical results indicate that LBM can simulate numerical problems with a high Ra reaching a steady state where we can depict the change of the flow pattern and enhancement of the heat transfer in the presence of heated diamond array.     

Energy modelling of fabrics wrinkle recovery behaviour

Wrinkle recovery behaviour is an important property of fabrics for apparel applications. Fifty fabrics of a variety of constructions have been objectively evaluated in order to study the wrinkle recovery after a deformation. The wrinkle recovery behaviour was studied based on energy modelling. To study their wrinkle recovery properties, fabrics are modelled with the energy method. It is shown that the more the energy dissipation is low, the more fabric is able to recover to its initial state and then the more residual deformation is low. Thus, the energy dissipation can be used to estimate the ability of the fabric to recover to its initial state. In this paper, we also studied the effect of the fatigue test after the repeated wrinkling. Further, the increase of the fatigue cycle number after repeated wrinkling resulted in an increase of the residual deformation and permanent deformation. This method allows us for better approximation of the real behaviour of multidirectional wrinkling of clothing during wearing.     

Elderly fall detection based on multi-stream deep convolutional networks

Multimedia Tools and Applications - Fall is the biggest threat to seniors, with significant emotional, physical and financial implications. It is the major cause of serious injuries, disabilities,...     

Long-time anodisation of titanium in sulphuric acid

The long-time behaviour of CP titanium in 1 M H₂SO₄ has been investigated. The authors revealed electrochemical behaviour during the long-time chrono-amperometric experiments. The ex-situ observations (EIS, ellipsometry, SEM and optical microscopy) brought out information concerning morphological changes of the surface as well as the change in the oxide thickness during the anodic oxidation process. From the obtained data, the authors developed a hypothesis describing the potentiostatic anodisation of titanium at voltages (up to 15 V) in 1 M H₂SO₄ with respect to time of anodisation.