Probabilistic Global Maximum Power Point Tracking Algorithm for Continuously Varying Partial Shading Conditions on Autonomous PV Systems

A photovoltaic (PV) string with multiple modules with bypass diodes frequently deployed on a variety of autonomous PV systems may present multiple power peaks under uneven shading. For optimal solar harvesting, there is a need for a control schema to force the PV string to operate at global maximum power point (GMPP). While a lot of tracking methods have been proposed in the literature, they are usually complex and do not fully take advantage of the available characteristics of the PV array. This work highlights how the voltage at operating point and the forward voltage of the bypass diode are considered to design a global maximum power point tracking (GMPPT) algorithm with a very limited global search phase called Fast GMPPT. This algorithm successfully tracks GMPP between 94% and 98% of the time under a theoretical evaluation. It is then compared against Perturb and Observe, Deterministic Particle Swarm Optimization, and Grey Wolf Optimization under a sequence of irradiance steps as well as a power-over-voltage characteristics profile that mimics the electrical characteristics of a PV string under varying partial shading conditions. Overall, the simulation with the sequence of irradiance steps shows that while Fast GMPPT does not have the best convergence time, it has an excellent convergence rate as well as causes the least amount of power loss during the global search phase. Experimental test under varying partial shading conditions shows that while the GMPPT proposal is simple and lightweight, it is very performant under a wide range of dynamically varying partial shading conditions and boasts the best energy efficiency (94.74%) out of the 4 tested algorithms.

一类非线性级联系统层次化执行器故障诊断方法研究

研究了一类非线性级联系统中执行器内部参数与全局系统运行的相关性问题,利用系统全局可测信息隔离故障执行器并识别执行器内部故障参数。应用可逆理论及基于模型的故障诊断方法,形成了一种系统级与设备级相结合的互联系统层次化执行器故障诊断方案。通过将执行器视为独立子系统与过程子系统互连,构成互连非线性动态系统;并进行互连系统的可逆性、局部参数的全局可观性和故障可诊断性等研究;在全局系统性能下降时能快速准确定位出局部故障参数,实现设备的鲁棒故障诊断。并利用集成换热器模型验证了所提出方案的有效性及鲁棒性。

基于FPGA的I/O控制器的设计和实现

对于计算机信息系统受到攻击基本上可以分为基于CPU和I/O控制器这两种。对于CPU的攻击已经被深入研究,各种成熟的对策也被广泛的应用。但是对于I/O控制器攻击的研究非常缺乏有效的保护机制。为了研究关于I/O控制器的攻击,使用FPGA可编程技术设计和实现了一款PCI Express总线的平台。平台能产生任意种类的关于PCI Express事务层的信息包,为研究各类I/O控制器的攻击提供了基础。

End-to-End Performance Evaluation of TCP Traffic under Multi-Queuing Networks

While Internet traffic is currently dominated by elastic data transfers, it is anticipated that streaming applications will rapidly develop and contribute a significant amount of traffic in the near future. Therefore, it is essential to understand and capture the relation between streaming and elastic traffic behavior. In this paper, we focus on developing simple yet effective approximations to capture this relationship. We study, then, an analytical model to evaluate the end-to-end performance of elastic traffic under multi-queuing system. This model is based on the fluid flow approximation. We assume that network architecture gives the head of priority to real time traffic and shares the remaining capacity between the elastic ongoing flows according to a specific weight.

A New Bi-Frequency Soil Smart Sensing Moisture and Salinity for Connected Sustainable Agriculture

Optimizing water consumption is a major challenge for more sustainable agriculture with respect for the environment. By combining micro and nanotechnologies with the offered solutions of IoT connection (Sigfox and LoRa), new sensors allow the farmer to be connected to his agricultural production by mastering in real time the right contribution needed in water and fertilizer. The sensor designed in this research allows a double measurement of soil moisture and salinity. In order to minimize the destructuring of the ground to insert the sensor, we have designed a cylindrical sensor, easy to insert, with its electronics inside its body to propose a low power electronic architecture capable of measuring and communicating wireless with a LoRa or Sigfox network or even the farmer’s cell phone. This new smart sensor is then compared to the current leaders in agriculture to validate its performance. Finally, the sensor has better performance than commercials, a better response time, a better precision and it will be cheaper. For the salinity measure, it can detect the level of fertilizer in the soil according to the need of farmers.

Advanced Thermopile IR Dual Line Sensor for Smart Home

This article presents all steps between the advanced design and the production of CMOS compatible thermoelectric effect infrared sensors dedicated to smart home applications. It will start by making a comparison between thermopile, bolometer and pyroelectric technologies. Although sensitivity performances available with bolometers appear to be better at first sight, it is found that thermopiles have non-negligible advantages that make them more suitable for this application field. Then the different steps necessary for the design will be described, starting from the thermoelectric model of the sensor (temperature gradient, electrical sensitivity, etc.) and considering all steps up to technological manufacturing in a clean room. The results obtained on the structures produced on a specific computer-controlled measurement bench (temperature regulation with an onboard preamplification card) will be presented. Finally, the results prove that the square structures have better performances (S = 82 V/W and NETD = 208 mK).

Design of a Smart Sole with Advanced Fall Detection Algorithm

Fall has become the second leading cause of unintentional injury, death, after road traffic injuries, for the elderly in Europe. This proportion will increase in the next decades and become more than ever a real public health issue. France was selected by the World Health Organization to be the first country to implement a program that reduces the coverage of the dependence. Commercial automatic fall detection devices can help seniors get back on their feet faster by reducing the time of emergency procedure. Many seniors do not take advantage of this potentially life-saving technology mainly because of intrusiveness constraints. After having reminded the context and the challenges of fall detection systems, this paper presents an original device which is unobtrusive, comfortable and very effective. The hardware architecture embedded into the sole and a new fall detection algorithm based on acceleration and time thresholds are presented. The algorithm introduces a new concept of differential acceleration to eliminate some drawbacks of current systems. Tests were carried out under real life conditions by 6 young participants for different ADLs. The data were analyzed blindly. We compared the detected falls and found a 100% sensibility and more than 93% sensitivity for all participants and scenarios.

Battery-Free Power Supply for Wireless Sensor Combining Photovoltaic Cells and Supercapacitors

This article exhibits the sizing, modelling, and characterization of a power supply (output 3.3 V, 200 mA max, 11 days full autonomy) dedicated to powering a wireless sensor node without a battery but usable as simply as with a battery. This system is modular for various light levels (indoor and outdoor). It is easily integrable into a sensor node, using only commercial circuits. The choices of the photovoltaic surface (amorphous silicon, η 5%, 35 cm2) and of the supercapacitors value (2x 25F, 2.7 V) are explained for permanent operation, considering the solar potential and the consumption. An original part of the paper is devoted to the issue of the startup, in which we demonstrate that after a particular preload, once installed, the device can start on request at the desired time (within 15 days) using as a trigger any light source, such as the LED of a mobile phone.

A Logarithmic-Complexity Algorithm for Nearest Neighbor Classification Using Layered Range Trees

Finding Nearest Neighbors efficiently is crucial to the design of any nearest neighbor classifier. This paper shows how Layered Range Trees (LRT) could be utilized for efficient nearest neighbor classification. The presented algorithm is robust and finds the nearest neighbor in a logarithmic order. The proposed algorithm reports the nearest neighbor in , where k is a very small constant when compared with the dataset size n and d is the number of dimensions. Experimental results demonstrate the efficiency of the proposed algorithm.

Algorithm and Design Methodology to Develop a PIFA with Optimized Reflection Coefficient for the ISM 868 MHz Band

This paper presents a methodological approach to design a printed Inverted F antenna for the ISM 868 MHz band. For this design, the ground plane dimensions were kept fixed and the meandered radiating arm was modified to obtain the best compromise integration/performances. This approach was then generalized to design meandered printed inverted F antennas.

Design, Integration and Characterization of a Tracking Patch: Application to Elderly Monitoring

According to the latest studies, the French population witnesses a high level of elderly. It follows from this phenomenon health troubles, fragility, and for some people suffering from cognitive problems, a daily need of monitoring and tracking in the fugues cases. It is in this context that comes our research program SACHA (Search and Computerize Human Acts). Our ambition is to develop an electronic patch able to trigger alarms, detect falls and provide geolocation service. Our studies were focused on the conception and the integration of different antennas and functionalities of this system in aim to ensure a good compromise “integration/performances”. Several prototypes have been tested and validated in a nursing home.

Study of Comparative Saturated Sliding Mode Control and LQR Controller

The saturation problem is the one of the most common handicaps for applying to real applications, especially the actuator saturation. This paper focuses on the robustness of the sliding mode control （SMC） which incorporates a saturation constraint technique compared to classical linear quadratic regulator （LQR） with saturation. In the first step, the authors present a design methodology of SMC of a class of linear saturated systems. The authors present the structure of the saturation, after that the synthesis of the sliding surface is formulate as a problem of root clustering, which leads to the development of a continuous and non-linear control law that ensures the reaching condition of the sliding mode. The second step is devoted to present briefly the LQR controller technique. Finally, to validate results, the authors demonstrate an example of a quarter of vehicle system.

Integration of a Dual GPS and ISM Antenna PIFA in a Human Body Patch for Elderly Tracking

This paper introduces the development of two Printed Inverted F Antennas (PIFA) to be integrated in a patch worn on the back of human body. This study is part of SACHA project (Search And Computerize Human Acts) whose main aim is to design a tracking device for monitoring the elderly suffering from Alzheimer disease. The first antenna frequency is 868 MHz and will be used to communicate with a specific SIGFOX communication technology. A second frequency (1575.42 MHz) is used for GPS geolocation. The proposed development is a part of research in Human Health Monitoring field, based on the monitoring of the behavior, the location and the position of the patient, and could deeply help the medical team or family to instantly respond through a warning generation.

A Novel Computing Method for Mutual Inductance

The design process for integrated inductors generally requires a geometry optimization step. During this step, many geometries must be simulated and fast and accurate formulae are therefore required for the computation of self and mutual inductances of turns. This paper especially deals with numerical evaluation of the mutual inductance of two coaxial circular wire loops. Several computation methods are presented and compared. Finally, an expression is built-up and proven to be very few computing time consuming and 1% accurate for any kind of geometry. The application of this expression to integrated inductive components modelization is recalled to mind, however, this work gives a general and fast computable solution to the electromagnetic problem.

Insight of surface treatments for CMOS compatibility of InAs nanowi

A CMOS compatible process is prese nted in order to grow self-catalyzed InAs nano wires on silic on by molecular beam epitaxy. The crucial step of this process is a new in-situ surface preparation under hydrogen (gas or plasma) during the substrate degassing combined with an in-situ arsenic ann eali ng prior to growth. Morphological and structural characterizati ons of the InAs nano wires are prese nted and growth mecha nisms are discussed in detail. The major in flue nee of surface termi nation is exposed both experime ntally and theoretically using statistics on ensemble of nanowires and density functional theory (DFT) calculations. The differences observed between Molecular Beam Epitaxy (MBE) and Metal Organic Vapor Phase Epitaxy (MOVPE) growth of I nAs nano wires can be explai ned by these differe nt surfaces termi nations. The transition between a vapor solid (VS) and a vapor liquid solid (VLS) growth mechanism is presented. Optimized growth conditions lead to very high aspect ratio nano wires (up to 50 nm in diameter and 3 micron in len gth) without passi ng the 410℃ thermal limit, which makes the whole process CMOS compatible. Overall, our results suggest a new method for surface preparation and a possible tuning of the growth mechanism using different surface termi nations.

SYSTEMS ENGINEERING RESEARCH

In this paper, we propose selected research topics that are believed central to progress and growth in the application of systems engineering （SE）. As a professional activity, and as an intellectual activity, systems engineering has strong links to such associated disciplines as decision analysis, operation research, project management, quality management, and systems design. When focussing on systems engineering research, we should distinguish between subjects that are of systems engineering essence and others that more closely correspond to those that are more relevant for related disciplines.

Functionalized liposomes for targeted breast cancer drug delivery

Despite the exceptional progress in breast cancer pathogenesis,prognosis,diagnosis,and treatment strategies,it remains a prominent cause of female mortality worldwide.Additionally,although chemotherapies are effective,they are associated with critical limitations,most notably their lack of specificity resulting in systemic toxicity and the eventual development of multi-drug resistance(MDR)cancer cells.Liposomes have proven to be an invaluable drug delivery system but of the multitudes of liposomal systems developed every year only a few have been approved for clinical use,none of which employ active targeting.In this review,we summarize the most recent strategies in development for actively targeted liposomal drug delivery systems for surface,transmembrane and internal cell receptors,enzymes,direct cell targeting and dual-targeting of breast cancer and breast cancer-associated cells,e.g.,cancer stem cells,cells associated with the tumor microenvironment,etc.

Blind identification of occurrence of multi-modality in laser-feedback-based self-mixing sensor

Self-mixing interferometry(SMI)is an attractive sensing scheme that typically relies on mono-modal operation of an employed laser diode.However,change in laser modality can occur due to change in operating conditions.So,detection of occurrence of multi-modality in SMI signals is necessary to avoid erroneous metric measurements.Typically,processing of multi-modal SMI signals is a difficult task due to the diverse and complex nature of such signals.However,the proposed techniques can significantly ease this task by identifying the modal state of SMI signals with 100%success rate so that interferometric fringes can be correctly interpreted for metric sensing applications.

Sliding walls: a new paradigm for fluidic actuation and protocol implementation in microfluidics

Currently,fluidic control in microdevices is mainly achieved either by external pumps and valves,which are expensive and bulky,or by valves integrated in the chip.Numerous types of internal valves or actuation methods have been proposed,but they generally impose difficult compromises between performance and fabrication complexity.We propose here a new paradigm for actuation in microfluidic devices based on rigid or semi-rigid walls with transversal dimensions of hundreds of micrometres that are able to slide within a microfluidic chip and to intersect microchannels with hand-driven or translation stage-based actuation.With this new concept for reconfigurable microfluidics,the implementation of a wide range of functionalities was facilitated and allowed for no or limited dead volume,low cost and low footprint.We demonstrate here several fluidic operations,including on/off or switch valving,where channels are blocked or reconfigured depending on the sliding wall geometry.The valves sustain pressures up to 30kPa.Pumping and reversible compartmentalisation of large microfluidic chambers were also demonstrated.This last possibility was applied to a“4D”migration assay of dendritic cells in a collagen gel.Finally,sliding walls containing a hydrogel-based membrane were developed and used to concentrate,purify and transport biomolecules from one channel to another,such functionality involving complex fluidic transport patterns not possible in earlier microfluidic devices.Overall,this toolbox is compatible with“soft lithography”technology,allowing easy implementation within usual fabrication workflows for polydimethylsiloxane chips.This new technology opens the route to a variety of microfluidic applications,with a focus on simple,hand-driven devices for point-of-care or biological laboratories with low or limited equipment and resources.