An efficient implementation of lattice-ladder multilayer perceptrons in field programmable gate arrays

The implementation efficiency of electronic systems is a combination of conflicting requirements, as increasing volumes of computations, accelerating the exchange of data, at the same time increasing energy consumption forcing the researchers not only to optimize the algorithm, but also to quickly implement in a specialized hardware. Therefore in this work, the problem of efficient and straightforward implementation of operating in a real-time electronic intelligent systems on field-programmable gate array (FPGA) is tackled. The object of research is specialized FPGA intellectual property (IP) cores that operate in a real-time. In the thesis the following main aspects of the research object are investigated: implementation criteria and techniques. The aim of the thesis is to optimize the FPGA implementation process of selected class dynamic artificial neural networks. In order to solve stated problem and reach the goal following main tasks of the thesis are formulated: rationalize the selection of a class of Lattice-Ladder Multi-Layer Perceptron (LLMLP) and its electronic intelligent system test-bed – a speaker dependent Lithuanian speech recognizer, to be created and investigated; develop dedicated technique for implementation of LLMLP class on FPGA that is based on specialized efficiency criteria for a circuitry synthesis; develop and experimentally affirm the efficiency of optimized FPGA IP cores used in Lithuanian speech recognizer. The dissertation contains: introduction, four chapters and general conclusions. The first chapter reveals the fundamental knowledge on computer-aideddesign, artificial neural networks and speech recognition implementation on FPGA. In the second chapter the efficiency criteria and technique of LLMLP IP cores implementation are proposed in order to make multi-objective optimization of throughput, LLMLP complexity and resource utilization. The data flow graphs are applied for optimization of LLMLP computations. The optimized neuron processing element is proposed. The IP cores for features extraction and comparison are developed for Lithuanian speech recognizer and analyzed in third chapter. The fourth chapter is devoted for experimental verification of developed numerous LLMLP IP cores. The experiments of isolated word recognition accuracy and speed for different speakers, signal to noise ratios, features extraction and accelerated comparison methods were performed. The main results of the thesis were published in 12 scientific publications: eight of them were printed in peer-reviewed scientific journals, four of them in a Thomson Reuters Web of Science database, four articles – in conference proceedings. The results were presented in 17 scientific conferences

ANALYSIS OF LASER POWER CONVERTERS IN LASER BASED POWER SUPPLIES

Napajanje elektronskih naprav v ekstremnih in industrijskih okoljih pogosto zahteva uporabo visoko zanesljivih električnih napajalnikov, imunih na raznovrstne okolijske in elektromagnete motenje. Zahtevane specifikacije takšnih napajalnikov je mogoče doseči z uporabo sistemov, ki za izvor energije uporabljajo svetlobo laserskih virov. Energija v obliki monokromatske svetlobe je na oddaljeno mesto vodena skozi električno neprevodni medij, s čimer je dosežena inherentna neobčutljivost takšnih napajalnih sistemov na vse vrste elektromagnetih motenj. Lasersko svetlobo vodimo bodisi brezkontaktno po zraku ali priporočljivejše po električno neprevodnem optičnem vlaknu. V slednjem govorimo o sistemih za prenos »moči po optičnem vlaknu« (ang. Power–over–Fiber systems, PoF). Monokromatsko svetlobo je za napajanje elektronskih naprav potrebno pretvoriti v enosmerno električno energijo, kar storimo s fotonapetostnimi pretvorniki optimiziranimi za pretvorbo monokromatske svetlobe laserskih virov – »pretvorniki laserske moči« (ang. Laser Power Converter, LPC). PoF sistem je zaključen s priključitvijo podpornega elektronskega vezja na izhod pretvornika laserske moči, ki poskrbi za prilagoditev napetostnega nivoja za zanesljivo napajanje elektronskih naprav. PoF sistemi napajanja elektronskih naprav so našli svoje mesto v ekstremnih in industrijskih okoljih zaradi lastnosti kot so: • imunost na elektromagnetne motnje (enosmerna in izmenična električna in magnetna polja, razelektritve ozračja, radiofrekvenčne motnje, …), • velika prebojna trdnost med izvorom energije in napajano napravo, • majhna teža vodnikov energije (optična vlakna), • pri poškodbi vodnikov energije ne prihaja do iskrenja, … Zaradi omenjenih lastnosti so bili PoF sistemi razviti in uporabljeni za napajanje: • senzorjev za merjenje parametrov visokonapetostnih daljnovodov, • elektronskih merilnikov pod vodno gladino, • elektronskih podsklopov naprav za magnetno resonanco, • brezpilotnih letal, • elektronskih implantatov v človeškem telesu, • kontrolnih podsistemov v satelitih, • nadzornih video kamer, • merilnikov obratovalnih parametrov vetrnih turbin, … Kljub uspešni implementaciji PoF sistemov v nekaterih nišnih aplikacijah, je prenos energije z lasersko svetlobo še vedno razmeroma neznana tehnološka rešitev. Razlogov za to je veliko, verjetno pa je eden glavnih nizek izkoristek takšnega prenosa energije, ki se v praksi na sistemski ravni giblje nekje med 10 % in 30 %. Največ vložene energije se izgubi pri pretvorbi elektrike v svetlobo, pri čemer sodobne laserske diode dosegajo izkoristke med 40 % in 70 % ter nadalje pri pretvorbi laserske svetlobe nazaj v elektriko, pri čemer najboljši pretvorniki laserske moči dosegajo učinkovitost pretvorbe med 40 % in 60 %. V večini praktičnih aplikacij izgube pri prvotni pretvorbi energije iz elektrike v svetlobo s sistemskega vidika niso problematične, saj je laser postavljen na mestu, kjer je zagotovljena oskrba s potrebno električno energijo. Večje omejitve predstavljajo približno polovične izgube energije pri pretvorbi laserske svetlobe v električno energijo, preostanek energije pa je še dodatno zmanjšan za 10 % do 20 % zaradi izgub na podporni elektroniki. Tako v praksi izgube na sprejemni strani omejujejo največjo električno moč, ki jo lahko napajani napravi zanesljivo zagotovi en pretvornik laserske moči, na približno 1 W. Takšna omejitev največje dovedene moči ne predstavlja večjih problemov za napajanje nizkoenergijskih senzorjev, vendar omejuje doseg splošne uporabnosti PoF sistemov. V želji po razširitvi uporabnosti PoF sistemov se pričajoča doktorska naloga osredotoča na odkrivanje glavnih izgubnih mehanizmov v pretvornikih laserske moči in podporne elektronike. Rezultati sistematične analize in kvantitativnega ovrednotenja izgub so pripeljali do konceptualnih predlogov za izboljšanje sedanjih pretvornikov laserske moči.Electronic devices in extreme and industrial environments often require specialized power supplies immune to a variety of environmental and electromagnetic interferences. Such requirements can be met with power supplies that use lasers as an energy source. The laser light can be transmitted to a powered electronic device either wirelessly through the air or preferably through electrically nonconductive optical fiber. In the latter case, such power supplies are commonly known as Power–over–Fiber (PoF) systems. Energy in the form of monochromatic light must be transformed into electrical energy to power electronic devices. This energy transformation is achieved with photovoltaic (PV) devices optimized for conversion of monochromatic laser light called Laser Power Converters (LPC). Theoretically possible light-to-electricity conversion efficiency of LPCs is impaired by a variety of optical and electrical losses and light energy that is not converted into electrical energy results in energy loss, which in return reduces PoF systems efficiency. For high system efficiencies, LPCs must be made out of an appropriately selected high-quality III-V semiconductors and currently, the best manufactured LPCs exceed 60% conversion efficiency at strictly controlled laboratory conditions. Even thou such a figure is unheard of for the solar cells, an optimized PV converter illuminated with monochromatic light can theoretically convert more than 75% of impinged light to electricity, under the same conditions as the stated manufactured LPC. In this thesis, the reason for such a discrepancy between theoretical and practical conversion efficiency is studied in details and further, novel supporting electronics for LPCs in PoF systems are devised and analyzed in order to increase the system efficiency

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Building Blocks for Adaptive Modular Sensing Systems

This thesis contributes towards the development of systems and strategies by which sensor and actuator components can be combined to produce flexible and robust sensor systems for a given application. A set of intelligent modular blocks (building blocks) have been created from which composite sensors (made up of multiple sensor and actuator components) can be rapidly reconfigured for the construction of Adaptive Modular Sensing Systems. The composite systems are expected to prove useful in several application domains including industrial control, inspection systems, mobile robotics, monitoring and data acquisition. The intelligent building blocks, referred to as transducer interface modules, contain embedded knowledge about their capabilities and how they can interact with other modules. These modules encapsulate a general purpose modular hardware architecture that provides an interface between the sensors, the actuators, and the communication medium. The geometry of each transducer interface module is a cube. A connector mechanism implemented on each face of the module enables physical connection of the modules. Each module provides a core functionality and can be connected to other modules to form more capable composite sensors. Once the modules are combined, the capabilities (e.g., range, resolution, sample rate, etc.) and functionality (e.g., temperature measurement) of the composite sensor is determined and communicated to other sensors in the enviornment. For maximum flexibility, a distributed software architecture is executed on the blocks to enable automatic acquisition of configuration-specific algorithms. This logical algorithm imparts a collective identity to the composite group, and processes data based on the capabilities and functionalities of the transducers present in the system. A knowledge representation scheme allows each module in the composite group to store and communicate its functionality and capabilities to other connected modules in the system

Efficient audio signal processing for embedded systems

We investigated two design strategies that would allow us to efficiently process audio signals on embedded systems such as mobile phones and portable electronics. In the first strategy, we exploit properties of the human auditory system to process audio signals. We designed a sound enhancement algorithm to make piezoelectric loudspeakers sound "richer" and "fuller," using a combination of bass extension and dynamic range compression. We also developed an audio energy reduction algorithm for loudspeaker power management by suppressing signal energy below the masking threshold. In the second strategy, we use low-power analog circuits to process the signal before digitizing it. We designed an analog front-end for sound detection and implemented it on a field programmable analog array (FPAA). The sound classifier front-end can be used in a wide range of applications because programmable floating-gate transistors are employed to store classifier weights. Moreover, we incorporated a feature selection algorithm to simplify the analog front-end. A machine learning algorithm AdaBoost is used to select the most relevant features for a particular sound detection application. We also designed the circuits to implement the AdaBoost-based analog classifier.PhDCommittee Chair: Anderson, David; Committee Member: Hasler, Jennifer; Committee Member: Hunt, William; Committee Member: Lanterman, Aaron; Committee Member: Minch, Bradle

MSAT-X: A technical introduction and status report

A technical introduction and status report for the Mobile Satellite Experiment (MSAT-X) program is presented. The concepts of a Mobile Satellite System (MSS) and its unique challenges are introduced. MSAT-X's role and objectives are delineated with focus on its achievements. An outline of MSS design philosophy is followed by a presentation and analysis of the MSAT-X results, which are cast in a broader context of an MSS. The current phase of MSAT-X has focused notably on the ground segment of MSS. The accomplishments in the four critical technology areas of vehicle antennas, modem and mobile terminal design, speech coding, and networking are presented. A concise evolutionary trace is incorporated in each area to elucidate the rationale leading to the current design choices. The findings in the area of propagation channel modeling are also summarized and their impact on system design discussed. To facilitate the assessment of the MSAT-X results, technology and subsystem recommendations are also included and integrated with a quantitative first-generation MSS design

A PCIe-based readout and control board to interface with new-generation detectors for the LHC upgrade

Questa tesi si riferisce principalmente al lavoro di design, sviluppo, produzione e validazione di una nuova scheda PCIe, chiamata Pixel-ROD (Pixel Read Out Driver), come naturale prosecuzione della precedente serie di schede di readout, oggi montate nel Pixel Detector di ATLAS. In modo particolare, questa scheda è stata pensata come evoluzione per l’elettronica off-detector presente ad ATLAS, la quale è principalmente composta da schede VME, conosciute come Back Of Crate (BOC) e Read Out Driver (ROD). Inoltre, tutte le schede ROD sono state commissionate e disegnate dal Laboratorio di Progettazione Elettronica dell’INFN e del DIFA a Bologna. Il progetto della scheda Pixel-ROD è cominciato due anni fa, poichè il trend generale per l’evoluzione dell’elettronica off-detector di LHC è quello di abbandonare la più vecchia interfaccia VME, per passare a quelle più nuove e veloci (come il PCIe). Inoltre, poichè i rivelatori di ATLAS e CMS saranno accomunati dallo stesso chip di readout che interfaccerà i futuri Pixel Detector, la Pixel-ROD potrebbe essere usata non solo per l’evoluzione di ATLAS ma anche per altri esperimenti. La caratteristica principale della Pixel-ROD è la possibilità di utilizzo sia come scheda di readout singola, sia in una catena reale di acquisizione dati, che si interfaccia con dispositivi di terze parti. Il lavoro che ho svolto in questa tesi si concentra principalmente sul design, lo sviluppo e l’ottimizzazione della scheda prima della sua fabbricazione. Dopo questa fase, utilizzando i prototipi prodotti, mi sono concentrato sul lavoro di test e validazione dei singoli componenti e delle singole interfacce montate sulla scheda. Questa fase non è ancora terminata e richiede molto tempo per essere svolta, a causa della complessità dell’elettronica che è presente sulla Pixel-ROD

The G0 Experiment: Apparatus for Parity-Violating Electron Scattering Measurements at Forward and Backward Angles

In the G0 experiment, performed at Jefferson Lab, the parity-violating elastic scattering of electrons from protons and quasi-elastic scattering from deuterons is measured in order to determine the neutral weak currents of the nucleon. Asymmetries as small as 1 part per million in the scattering of a polarized electron beam are determined using a dedicated apparatus. It consists of specialized beam-monitoring and control systems, a cryogenic hydrogen (or deuterium) target, and a superconducting, toroidal magnetic spectrometer equipped with plastic scintillation and aerogel Cerenkov detectors, as well as fast readout electronics for the measurement of individual events. The overall design and performance of this experimental system is discussed.Comment: Submitted to Nuclear Instruments and Method

Wireless communication, identification and sensing technologies enabling integrated logistics: a study in the harbor environment

In the last decade, integrated logistics has become an important challenge in the development of wireless communication, identification and sensing technology, due to the growing complexity of logistics processes and the increasing demand for adapting systems to new requirements. The advancement of wireless technology provides a wide range of options for the maritime container terminals. Electronic devices employed in container terminals reduce the manual effort, facilitating timely information flow and enhancing control and quality of service and decision made. In this paper, we examine the technology that can be used to support integration in harbor's logistics. In the literature, most systems have been developed to address specific needs of particular harbors, but a systematic study is missing. The purpose is to provide an overview to the reader about which technology of integrated logistics can be implemented and what remains to be addressed in the future