Antoine Vianou

Formal Modeling of Grafcets With Time Petri Nets

Grafcet standard (IEC60848) is a formalism used in the world of manufacturing control, at the behavioral specification stage of a system. For specifying safe-critical systems, mathematical models associated with model-checking tools are necessary for the validation of the correctness. However, grafcets (meaning grafcet diagrams) are only semiformal models since certain aspects may be a source of different interpretations. The usual practice is to go through an intermediate formalism. In this brief, time Petri nets (TPNs) are chosen because they combine simplicity with wide-spreading and they also allow quantitative time analyses useful for the verification of real-time specifications. The main goal is to propose a principle of transforming a grafcet into TPN and to define the rules of this translation. The obstacle to overcome is to conciliate synchronous semantics of grafcet with asynchronous semantics of TPN.

D-C ACO-OFDM and DCO-OFDM for passive optical network: Performance comparison in IM/DD fiber link

We present a comparative study of Diversity-Combined Asymmetrically Clipped Optical OFDM (D-C ACO-OFDM) and DC-biased Optical OFDM (DCO-OFDM) techniques in 17Gbps intensity modulated and direct detected (IM/DD) fiber link of passive optical network (PON). From simulation results obtained with realistic components parameters, we find that D-C ACO-OFDM offers an improved demodulation than DCO-OFDM. Using 4QAM format and split ratio of 1×32, D-C ACO-OFDM is showed to reach 45.3km distance which is almost the double distance transmission of DCO-OFDM with the same modulation order. We also show at BER of 10-3, that 20km transmission distance can be reached at 24Gbps 4QAM D-C ACO-OFDM data rate and then D-C ACO-OFDM is a suitable efficient cost-effective solution for GPON deployment with benefit of use of low-cost laser bandwidth in comparison with DCO-OFDM. At the same BER performance, in comparison with D-C ACO-OFDM at high bit rates transmission, DCO-OFDM promises to deliver higher throughput. The Bit Error Rate (BER) performance value is fixed to 10-3 (limit value when Forward Error Codes are used).

Diversity-Combining in asymmetrically clipped optical OFDM for PON IM/DD fiber link

We show taking into account realistic component parameters, the performance analysis of Diversity-combined Asymmetrically Clipped OFDM technique in intensity modulated and direct detected (IM/DD) passive optical network (PON) fiber link. The Diversity-Combined ACO-OFDM is shown to give better BER performance than conventional ACO-OFDM. Data rate of 13.2Gbps can be transmitted using 4-QAM/D-C ACO-OFDM through 60km unamplified IM/DD fiber link with split ratio of 128 users and 3dBm DFB-Laser. Throughput gain of 2.8Gbps is achieved when using the diversity-combining method. The BER performance value is fixed to 10-3 (limit value when Forward Error Codes are used).

Performance analysis of known unipolar optical OFDM techniques in PON IM/DD fiber link

We show taking into account realistic component parameters, the performance analysis of known power efficient unipolar optical OFDM techniques in a 10Gbps intensity modulated, direct detected (IM/DD) fiber link for passive optical network (PON) application. The Diversity-Combined ACO-OFDM is shown to give better BER performance in overall studied case and to be suitable to efficiently compensate frequency selective distortion of optical fiber link channel. We also show that data rate of 10Gpbs with split ratio of 128 and 4-QAM modulation format can be sent through 60km of SSMF fiber using Noise cancellation ACO-OFDM and 109km using Diversity-Combined ACO-OFDM. The BER performance value is fixed to 10-3 (limit value when Forward Error Codes are used).

Complementarity between Solar and Wind Energy Potentials in Benin Republic

This paper presents a study to show the complementarity between solar and wind energy potentials in Benin Republic. Daily wind speed data in the coast of Cotonou city, precisely in Cadjehoun district, has been used to assess wind energy potential. Solar potential is evaluated using spatio temporal daily solar radiation data covering the country. In this research, we have found the locations offering optimal complementarity between solar and wind energy. The complementarity is measured with Pearson correlation coefficient, which is used as objective function to be minimized. The optimization method used is Particle Swarm Optimization (PSO), which has been implemented in Matlab®. We showed that an optimal complementarity is obtained between the coast of Cotonou in the ‘Littoral’ department and the central part of the country in the ‘Collines’ department.

Embedding time Petri nets

This paper presents a tool (PN2A) which embeds Time Petri Nets (TPN) to Arduino micro-controller architecture. PN2A imports TPN and generates Arduino sketches, which can be then compiled and uploaded to a micro-controller architecture. Some transitions (resp. places) of the transition set (resp. place set) can be assigned to pins of the micro-controller. Theses two types of transitions generates a new firing semantics combining weak and strong semantics. Embedded, the TPN becomes partially non-autonomous and can be defined as a microcontroller Synchronised Time Petri net (mSTPN).