École Nationale Supérieure de l'Électronique et de ses Applications (also known as ENSEA) is a graduate school (grande école) of electrical engineering and computer science, located in Cergy (in Val d'Oise department) close to Paris in France.It was founded in 1952 under the name of ENREA and became ENSEA in 1976..
We study a class of singularly perturbed impulsive linear switched systems exhibiting switching between slow and fast dynamics. To analyze their behavior, we construct auxiliary switched systems evolving in a single time scale. We prove that the stability or instability of these auxiliary systems directly determines that of the original system in the regime of small singular perturbation parameters.
We present a photoreceiver assembly optimized through comprehensive modeling of the photodiode (PD), the transimpedance amplifier (TIA), and their interconnection. This allows an early and accurate optical signal-to-noise ratio (OSNR) prediction during the TIA design. Fabricated in a $0.5-\mu \mathrm{m}$ InP DHBT technology, the standalone TIA achieves a $59-\text{dB} \Omega$ transimpedance gain and a $70-\text{GHz}$ electrical bandwidth, supporting PAM-4 operation up to 100 GBd without digital signal processing. When wire-bonded to a 50 GHz PD, the photoreceiver exhibits a flat electro-optical response with $\mathbf{5 5 ~ G H z}$ of bandwidth. Open PAM-4 eye diagram is demonstrated up to 112 GBd with a $1.56 \text{pJ} /$ bit efficiency, using a 6 -tap off-line feed-forward equalizer. High linearity is obtained, with a 1 -dB gain compression point reached at 3.5 dBm input optical power, corresponding to a $650-\text{mV}$ electrical output swing. These results pave the way to beyond-112-GBd direct-detection optical transceivers.
. This paper discusses the explicit form of the generators of skew cyclic codes of an arbitrary length with nontrivial automorphisms and derivations over a nonchain ring R = & Zopf;4+v & Zopf;4+w & Zopf;4i where v2 = w2 = vw = wv = 0. We address the reversibility problem for these codes by presenting a novel approach to resolve it and establish reverse and reverse-complement constraints for these codes, ensuring their biological feasibility. In addition, we propose an unconventional way to construct DNA codes by extending reversible codes in a specific manner and obtain several DNA codes using this technique. In comparison to the known codes, we provide some new classical and DNA codes by employing various Gray maps under different automorphisms and derivations, which have better parameters.
The increasing use of autonomous mobile robots in domains such as logistics, agriculture, and disaster management increasingly relies on cooperating robot swarms. However, most coordination approaches assume reliable and continuous communication between agents. In practice, communication channels are subject to interruptions, packet losses, and delays, which can significantly degrade performance and mission safety. This paper presents a hybrid approach combining ROS 2, Gazebo Classic, MATLAB/Simulink, and time-scale theory for trajectory planning and tracking of a differential robot swarm under random communication interruptions. The control strategy is based on a leader-follower architecture coupled with Nonlinear Model Predictive Control (NLMPC) for the leader, while the followers maintain predefined positional offsets. Communication interruptions are modeled as discrete jumps within the timescale framework, allowing a unified treatment of continuous robot dynamics and discrete information exchanges. Simulation results show that the swarm successfully tracks the reference trajectory and maintains formation despite interruptions of varying duration and frequency, demonstrating the robustness of the proposed approach.
This textbook is a complete, self-sufficient, self-study/tutorial source of mathematical problems, essential in future studies and engineering practice.
