In the field of urban and green mobility, electric car-sharing networks have recently emerged as one of the promising alternatives, dealing with both environmental and transportation issues. Despite the increasing success of the shared mobility concept over the world, the design and management of such urban mobility systems implies strategic, tactical and operational challenges. To support designers and operators, all these issues constitute an emerging and challenging research topic, aiming to develop techniques and tools for modeling, analysis and optimization of such complex systems. In this contribution, based on the modeling and analysis power of stochastic timed Petri nets, a discrete event simulation approach is developed, taking into account their dynamic behavior complexities due to their self-service mode and characteristics including capacities of the stations, energy availability, rebalancing and maintenance activities. A real-life application is presented, to demonstrate the applicability and the potential of the proposed modeling and simulation analysis approach.Note to Practitioners—To support designers, providers and managers of shared mobility programs, performance and optimization models and decision-making tools are needed. In this contribution, we deals with a powerful and modular stochastic timed Petri net methodology suitable for performance modeling and simulation analysis of such complex dynamical systems. The authors believe that this discrete event dynamic approach has significant promise for the future and to influence economic viability and operational efficiency of such emerging urban transportation systems.

In this paper, a new optimization problem is proposed for improvement of PWM control of an inverter that supplies a generic RLE load. Two objectives functions are studied separately: Weighted Total Harmonic Distortion (WTHD) of load voltages and total losses. The gap contribution is related to optimize the zero sequence component waveform by defining special decision variables. By doing so, the proposed PWM strategy allows to improve the WTHD and efficiency of converters by keeping a classical PWM implementation scheme. Moreover this approach has the same way of thinking than the two main different classes of PWM strategies that are Space-Vector-based PWM (SVM) methods and classic carrier-based PWM methods (CBPWM). It is well known that there is an equivalence between SVM and CBPWM through the zero sequence component injection. So, optimized zero sequences are proposed for the two objectives functions considered, and the simulation results show a significant improvement compared to classical CBPWM strategies. Moreover the proposed strategy allows an implementation on existing hardware by modifying only the modulation component software.

The Revolution in the transportation domain have been beneficial in term of improving the quality of life. The Intelligent Transportation System (ITS) [1] are developed applications that objective to make transportation infrastructure more intelligent, which ensure safety and traffic efficiency. The communication between different entities comprising the ITS is ensured by the Vehicular AdHoc Networks (VANET). Routing protocols look for the route of forwarding data packets from the source vehicle to the destination vehicle. A routing protocol plays an important role in finding the shortest time and path of the route. This paper presents Fuzzy Trust Optimized Link State Routing (FT-OLSR) protocol, which is a new security extension of the existing OLSR protocol. The FT-OLSR is based on exchanging control messages with one-hop neighbors to allow each vehicle to calculate the trust-level of its neighbors using fuzzy logic. To demonstrate the proposed approach, we have implemented the system on a network simulator 2 (NS2). The simulation results show that FT-OLSR can increase the performance and security of the existing OLSR protocol.

The development of new information and communication technologies is contributing to the emergence of a new generation of real-time services in various fields of application. In the area of intelligent transport systems, these new services also include connected vehicles that enable vehicles to collect and disseminate information, safety alerts and make driving smarter and more environmentally friendly. More and more, they concern power-assisted or fully autonomous vehicles. In this paper we propose an architecture of agents and we project it on a multi-agent transport simulator (MATSim). In order to improve the performance of the DriverAgent in the simulation an alternative approach to score the DriverAgent plans is proposed. The results show that the proposed scoring function is able to ensure that agents improve their plans at each iteration performing on the same if not better level than the current scoring function.

Public Bicycle-Sharing Systems (PBSS) have been appearing in more and more cities around the world in the last few years. Although their apparent success as an alternative form of public transportation mode, there are major challenges confronting the operators while few scientific works are available to support such complex dynamical systems to influence their economic viability and operational efficiency. One of the most crucial factors for the success of a PBS system is its ability to ensure that bicycles are available for pick up and vacant berths available for bicycle drop off at every station. In this paper, we develop an original discrete event approach for modelling and performance evaluation of public bicycle-sharing systems by using Petri nets with time, inhibitor arcs and variable arc weights.

Security and error control coding are two crucial aspects of the digital communication systems. The deployment of data transmission systems easy to eavesdrop, such as wireless systems, makes strategic the protection of the data secrecy. This paper presents an encryption scheme based on the dynamic observation of the reciprocal propagation channel between the legitimate nodes. A “session key”, generated from the Complex Impulse Response (CIR) measurements, manages the channel coding system, namely a turbo-code. This scheme allows to jointly perform an error control and dynamic coding in only one step. This scheme allows a dynamic security coding without change of the hardware structure of the transceiver devices.

Bayesian recursive inference of phase in additive Gaussian noise environments is studied. A tractable conjugate system is established using a von Mises distribution. Its shaping parameter, re, is studied, to reveal the link with classical phase estimation via matched transforms. Uncertainty quantifiers involve a modified Bessel function kernel. The optimal predictor of data is derived in the presence of phase uncertainty. The theory is applied in phase synchronization for a digital receiver, where phase is distributed as a mixture of von Mises. A fully Bayesian treatment of the decoding problem for phase-uncertain carriers results. Simulation results provide evidence for the improvement in accuracy over a certainty-equivalent-based prediction.

In traditional framework of Compressive Sensing (CS), only sparse prior on the property of signals in time or frequency domain is adopted to guarantee the exact inverse recovery. Besides sparse prior, cluster prior is introduced in this paper in order to investigate a class of structural sparse signals, called clustered sparse signals. A hierarchical statistical model is employed via Bayesian approach to model both the sparse prior and cluster prior and Markov Chain Monte Carlo (MCMC) sampling is implemented for the inference. Unlike the state-of-the-art algorithms based on the cluster prior, the proposed algorithm solves the inverse problem without any prior knowledge of the cluster parameters, even without the knowledge of the sparsity. The experimental results show that the proposed algorithm outperforms many state-of-the-art algorithms.

Compressive sensing is a new methodology to capture signals at sub-Nyquist rate. To guarantee exact recovery from compressed measurements, one should choose specific matrix, which satisfies the Restricted Isometry Property (RIP), to implement the sensing procedure. In this letter, we propose to construct the sensing matrix with chaotic sequence following a trivial method and prove that with overwhelming probability, the RIP of this kind of matrix is guaranteed. Meanwhile, its experimental comparisons with Gaussian random matrix, Bernoulli random matrix and sparse matrix are carried out and show that the performances among these sensing matrix are almost equal.

This letter deals with the CramrRao bound for the estimation of a hybrid vector with both random and deterministic parameters. We point out the specificity of the case when the deterministic and the random vectors of parameters are statistically dependent. The relevance of this expression is illustrated by studying a practical phase estimation problem in a non-data-aided communication context.

In this letter we present a low-complexity architecture designed for the decoding of block turbo codes. In particular we simplify the implementation of Pyndiah's algorithm by not storing any of the concurrent codewords generated by the list decoder.

This paper is concerned with the design of block turbo codes for very high bit rate applications. We first introduce an original low-complexity architecture designed for the iterative decoding of product codes. The implementation of the Chase-Pyndiah algorithm is simplified by not memorizing any of the list decoding concurrent code words. We then illustrate that such block turbo codes allow some bit rate improvement in the context of local loop transmission

This letter presents an original phase synchronization scheme designed for block turbo coded systems. This is a low-complexity scheme. It copes with low signal-to-noise ratios, taking complete advantage of the turbo coding possibilities. We display various results, showing that the proposed algorithm is able to process blocks of a few hundreds bits and that it tackles the case of large quadrature amplitude modulation constellations very well and with no phase ambiguity.

This paper concerns a new synchronizing scheme designed for block turbo coded system. The phase estimation relies on the feedback of the extrinsic information. A near optimum version of the algorithm based on the block turbo decoder devised by Pyndiah allows easy implementation. We display various results showing that the proposed algorithm is able to track frequency shifts and that it works very well in the case of general Quadrature Amplitude Modulation (QAM) constellations. We also show that this turbo synchronizer works at low Signal to Noise Ratios (SNR) taking completely advantage of the turbo coding possibilities.

The signal-to-noise ratio (SNR) threshold behavior is studied in the frame of data-aided carrier synchronization in additive white Gaussian noise. The closed form expression of the Chapman-Robbins bound, relative to the carrier frequency offset estimation is first established then used to derive an indicator of the SNR threshold. For a given sequence of pilot symbols, the threshold region is localized at the departure of the Chapman-Robbins bound from the Cramer-Rao bound. The data-aided maximum likelihood estimator is considered to examine the derived indicator usefulness.

In this paper we illustrate how to use the advantage of the differential flatness and the high order sliding mode control to deal with the problem of the trajectory planning and robust tracking of a car like robot.

Many multi-user receivers have been developed to mitigate the effects of both multipath and interference in CDMA radiocommunication networks. However, despite of these works, very few papers have been devoted to the implementation of these receivers and, more precisely, to the channel estimation problem in both the multi-user and FDD UMTS context. Assuming specular propagation channels and a multi-sensor receiver, the purpose of this paper is to present direct and turbo multi-user schemes for the joint estimation of the impulse response of the propagation channels between each user and each sensor for the FDD UMTS uplink. The quality of the latter are then evaluated through the bit error rate (BER) computation at the output of two receivers (2D-RAKE and decorrelator receiver) adapted to the FDD UMTS uplink.