306 research outputs found
ASTF: Visual Abstractions of Time-Varying Patterns in Radio Signals
A time-frequency diagram is a commonly used visualization for observing the
time-frequency distribution of radio signals and analyzing their time-varying
patterns of communication states in radio monitoring and management. While it
excels when performing short-term signal analyses, it becomes inadaptable for
long-term signal analyses because it cannot adequately depict signal
time-varying patterns in a large time span on a space-limited screen. This
research thus presents an abstract signal time-frequency (ASTF) diagram to
address this problem. In the diagram design, a visual abstraction method is
proposed to visually encode signal communication state changes in time slices.
A time segmentation algorithm is proposed to divide a large time span into time
slices.Three new quantified metrics and a loss function are defined to ensure
the preservation of important time-varying information in the time
segmentation. An algorithm performance experiment and a user study are
conducted to evaluate the effectiveness of the diagram for long-term signal
analyses.Comment: 11 pages, 9 figure
Electrify Atwater Kent
The Electrify Atwater Kent project aims to breathe new life into the dull, dreary building of Atwater Kent. LED stairs, bringing a modern look to the front stairwell, as well as the RasPiano, with customizable filters and visualizations to demonstrate the discipline of signal processing, will be installed in the building. With a full installation the project aimsto make Atwater Kent not just a more welcoming space that students feel comfortable studying in, but an inspiration for future engineers as well
Investigation and modeling of viscoelastic moduli for multilayered polymeric systems using high frequency ultrasonic waves
Mechanical characterization of both the bulk and individual layer properties of layered polymer stacks provides important information for their use in novel applications. A single technique to measure both the bulk and layer properties is atempted. Ultrasonic testing provides an opportunity to determine the mechanical characteristics for layered samples in the form of the complex mechanical moduli. These moduli express the viscoelastic properties of the materials. Using ultrasound, this can be done for the bulk and the layers in a single test. With ultrasound, the ability to determine the complex moduli in single layers has been demonstrated. The moduli were determined within the expected range. The ultrasonic testing has also allowed the determination of the speed of sound of the individual layers in a 2 layer sample consisting of layers of Polycarbonate and Poly(methyl methacrylate). Internal interference limited the ability to measure attenuation. To attempt to allow for analysis of these complex waveforms, a secondary technique for waveform analysis has been proposed and developed. This method employs a finite element simulation to replicate the experiment. By deriving a simulation with the complex moduli as inputs, it is possible to use the simulation results to measure the moduli of multilayered samples. This is done comparatively through iteration of the simulation inputs. When a set of inputs creates a simulated result matching the experimental scans, a solution has been found. A preliminary version of the simulation is presented and demonstrated
Sistemas de teste automĂĄticos para transceivers NG-PON2
Optical communications have had a fundamental role in conecting people
worldwide. More than ever, there has been an incessant necessity to turn
technology more ubiquitous
With recent advancements in optical technology, it has become possible
to keep up with the demand for higher transmission rates in upstream or
downstream, higher bandwidth e still guaranteeing Quality of Service (QoS)
among inumerous users
This emerging necessity has taken telecommunication companies to inovate
in the area of development regarding optical equipment and also dealing
with the referred necessities. For this to happen, good quality control,
calibration e testing of produced parts is of paramount importance.
The work cut out for this dissertation is focused on the improvement and
addition of funtionalities to a test-board designed to perform measurements
of BER levels, calibration and maintenance of parts according to the newest
optical standard(New Gigabit Passive Optical Network 2 (NGPON2)) that
operates in maximum rates of 10Gb/s per channel.
In the rst part of this work, emphasis is given to the development of a slave
Inter Integrated Circuit (I2C) module that ensures connection between the
test board and the user, supplying BER values measured through a block
dedicated to measure BER levels. Later the same module will allow to
access all micro-controlers of the test-board, ensuring calibration functions.
On a second part, a characterization of different transceivers of different
Field Programmable Gate Array (FPGA)s is performed, consisting of an
eye diagram analysis of the transceivers and if possible, to test 10Gb/s
continuous mode through BER curves assessing their response.
Finally, a comparison is made between all transceivers, the obtained response
along with all the respective results, will contribute to the source project
of the automatic test board developed at PICadvanced with the intent on
evaluating 10 Gigabit Small Form Factor Pluggables (XFP) production.As comunicaçÔes tĂȘm vindo a ter um papel fundamental em interligar todas
as pessoas do mundo. Mais do que nunca, tem havido uma incessante
necessidade de tornar a tecnologia mais ubĂqua.
Com o recente avanço e desenvolvimento da tecnologia Optica, tem sido
possĂvel acompanhar a demanda por altas taxas de transmissĂŁo em upstream
ou downstream, maior largura de banda e ainda garantir Quality of Service
(QoS) entre Ănumeros utilizadores, etc. . .
Esta necessidade emergente tem levado empresas de telecomunicaçÔes a inovar
na ĂĄrea de desenvolvimento de equipamento Ăłptico e por consequente,
comaltar as necessidades referidas. Para isto acontecer tem de haver um
bom controlo, calibração e teste de peças produzidas.
O trabalho desta dissertação dedica-se ao melhoramento e acrescento
de funcionalidades a uma placa de testes desenhada para desempenhar
mediçÔes de nĂveis de Bit Error Ratio (BER), calibração e manutenção de
peças para o novo standard óptico (New Gigabit Passive Optical Network 2
(NGPON2)) que recorre ao uso de taxas mĂĄximas de transmissĂŁo de 10Gb/s
por canal
Na primeira parte do trabalho Ă© dado foco ao desenvolvimento de um mĂłdulo
escravo Inter Integrated Circuit (I2C) que visa estabelecer o contacto entre
a placa de calibração e o utilizador fornecendo os valores de BER medidos
atravĂ©s de um bloco dedicado a medir o nĂvel de BER. Mais tarde este
mĂłdulo servirĂĄ para poder aceder aos micro-circuitos da placa de testes
podendo realizar funçÔes de calibração.
Numa segunda parte, é realizada uma caracterização de diferentes
transceivers de diferentes Field Programmable Gate Array (FPGA)s, a caracterização consiste numa anålise do diagram de olho de transceivers e ainda
sendo possĂvel, testar o modo contĂnuo nas mesmas, atravĂ©s curvas de BER
para avaliar a sua resposta.
Por fim, é feita uma comparação entre os mesmos transceivers, além de
que todos os resultados obtidos irĂŁo contribuir para a o projecto fonte da
placa de testes automatizada desenvolvida pela PICadvanced com o intuito
de avaliar a produção de 10 Gigabit Small Form Factor Pluggables (XFP).Mestrado em Engenharia Eletrónica e TelecomunicaçÔe
Single-Cell Impedance Spectroscopy
Impedance spectroscopy (IS) is an important tool for cell detection and characterization in medical and food safety applications. In this thesis, the Cal Poly BioïŹuidics Labâs impedance spectroscopy system was re-evaluated and optimized for single-cell impedance spectroscopy. To evaluate the IS system, an impedance spectroscopy bioMEMS chip was fabricated in the Cal Poly Microfabcrication lab, software was developed to run IS experiments, and studies were run to validate the system. To explore IS optimization, Maxwellâs mixture theorem and the Schwartz-Christoffel transform were used to calculate an analytic impedance solution to the co-planar electrode system,a novel volume fraction to account for the non-uniformity of the electric ïŹeld was developed to increase the accuracy of the analytic solution and to investigate the effect of cell position on the impedance spectrum, a software program was created to allow easy access to the analytic solution, and FEA models were developed to compare to the analytic solution and to investigate the effect of complex device geometry
Visualisation de l'information appliquée à l'analyse et à l'attribution de performances financiÚres
Croesus Finansoft dĂ©veloppe depuis 28 ans un logiciel intĂ©grĂ© de gestion de portefeuille pour les firmes de courtages et les conseillers indĂ©pendants. Leur application est prĂ©sentement utilisĂ©e par la plupart des grandes firmes au pays, incluant les financiĂšres CIBC, Banque Nationale, Valeurs MobiliĂšres Desjardins et TD. Lâapplication dĂ©veloppĂ©e par lâentreprise doit donc gĂ©rer des tables de donnĂ©es contenant souvent plus dâun milliard de transactions.
Pour lâentreprise, le dĂ©fi est de taille. Lâapplication doit offrir une vue cohĂ©rente des portefeuilles des investisseurs, en plus de guider les gestionnaires quant aux nouvelles possibilitĂ©s dâinvestissement, au suivi des objectifs de placement, des calculs de rendement, de performance, etc. MalgrĂ© les diffĂ©rentes avancĂ©es technologiques, certaines de ces tĂąches sont encore trĂšs difficiles Ă effectuer, principalement Ă cause de la quantitĂ© de donnĂ©es impliquĂ©es.
Lâanalyse des performances des portefeuilles dâinvestissements est particuliĂšrement problĂ©matique dans ces circonstances. Lâanalyse de performances ne se limite pas simplement Ă comparer des rendements obtenus Ă diffĂ©rents moments dans le temps. Il sâagit dâun processus complexe qui demande la corrĂ©lation dâune multitude dâinformations afin dâobtenir une vue complĂšte de la situation. Les performances des investissements sont toujours Ă©valuĂ©es par rapport Ă une rĂ©fĂ©rence, par exemple un indice de marchĂ©. Lâattribution de performances tente dâexpliquer dâoĂč proviennent les Ă©carts de rendement par rapport Ă cette rĂ©fĂ©rence. Est-ce explicable par le fait que les investisseurs ont choisi des titres ayant offert des rendements supĂ©rieurs Ă ceux de lâindice ? Ou encore parce quâils ont investi davantage dans les obligations Ă long terme, limitant ainsi leur exposition au risque ?
Lâoutil dĂ©veloppĂ© par Croesus permet facilement de mesurer les performances dâun seul portefeuille ou dâun petit groupe de portefeuilles. Effectuer cette analyse pour tous les clients dâune succursale simultanĂ©ment devient beaucoup plus complexe. Croesus ne supporte pas non plus lâattribution de performances. Pour les gestionnaires de lâentreprise, offrir ces fonctionnalitĂ©s sâavĂšre un enjeu de taille, surtout Ă cause de la quantitĂ© de donnĂ©es impliquĂ©es. Comment prĂ©senter ces informations Ă lâexpert sans crĂ©er une surcharge dâinformation ? Comment permettre dâidentifier facilement les problĂšmes dans les donnĂ©es, les tendances gĂ©nĂ©rales, les Ă©carts par rapport aux rĂ©fĂ©rences, de façon Ă ce que des actions concrĂštes puissent ĂȘtre mises en place afin de corriger la situation ?
La visualisation permet de tirer profit de la capacitĂ© humaine Ă interprĂ©ter des images beaucoup plus rapidement et efficacement que des donnĂ©es numĂ©riques ou textuelles. Elle vise Ă augmenter les capacitĂ©s de traitement de lâhumain, de façon Ă ce quâil soit conservĂ© dans le processus dâanalyse, contrairement aux processus de dĂ©cisions automatisĂ©s. Bien que la visualisation soit un domaine actif de recherche depuis de nombreuses annĂ©es, trĂšs peu de solutions adaptĂ©es Ă la rĂ©alitĂ© de la finance, et encore moins Ă lâanalyse des performances, ont Ă©tĂ© prĂ©sentĂ©es jusquâĂ prĂ©sent.
Cette thĂšse explore diffĂ©rentes techniques de visualisation permettant de simplifier le processus dâanalyse de performances financiĂšres dans le contexte de gestion de portefeuilles de lâapplication dĂ©veloppĂ©e par Croesus. Elle prĂ©sente les rĂ©sultats de trois projets distincts rĂ©alisĂ©s au cours des derniĂšres annĂ©es, tous liĂ©s Ă lâanalyse des performances financiĂšres.
Le premier projet prĂ©sente une technique dâinteraction novatrice permettant de simplifier lâanalyse des performances sur un graphique linĂ©aire simple (line graph). Que ce soit pour comparer les rendements de plusieurs centaines de portefeuilles simultanĂ©ment ou pour plusieurs centaines de titres dâun secteur dâactivitĂ©, les graphiques linĂ©aires sont rapidement surchargĂ©s dâinformation, rendant lâanalyse plutĂŽt complexe. Lâoutil proposĂ©, VectorLens, permet dâexplorer les donnĂ©es en offrant des techniques de sĂ©lection avancĂ©es. La principale contribution concerne la sĂ©lection angulaire. Dans la mesure oĂč le graphique prĂ©sente des rendements, la pente des droites encode lâessentiel de lâinformation. VectorLens tire profit de cette caractĂ©ristique et permet, en un seul mouvement, de sĂ©lectionner rapidement et efficacement les Ă©lĂ©ments en fonction de leur pente, moyennant une marge Ă©tablie de façon dynamique. Lâoutil intĂšgre Ă©galement dâautres outils de sĂ©lection, incluant la sĂ©lection par zone (pinceau), la sĂ©lection par catĂ©gories, etc. Il est Ă©galement possible de combiner plusieurs lentilles VectorLens pour effectuer des requĂȘtes plus complexes. La technique a Ă©tĂ© comparĂ©e aux principales techniques de sĂ©lection de courbes dans le cadre dâune expĂ©rience contrĂŽlĂ©e en laboratoire. Les rĂ©sultats ont dĂ©montrĂ© que VectorLens offrait des performances supĂ©rieures ou Ă©gales dans la plupart des cas, en plus dâĂȘtre prĂ©fĂ©rĂ©e par la plupart des utilisateurs.
Le deuxiĂšme projet propose une nouvelle technique de visualisation permettant de sĂ©parer efficacement les couches dâinformations sur un graphique linĂ©aire simple. Cette technique sâavĂšre intĂ©ressante pour comparer les rendements de titres de diffĂ©rents secteurs, ou mĂȘme les rendements de portefeuilles de diffĂ©rents clients, gestionnaires ou mĂȘme succursales, par exemple. PlutĂŽt que dâutiliser uniquement la couleur pour sĂ©parer les diffĂ©rents groupes dâĂ©lĂ©ments, cette technique consiste Ă exploiter lâespace inutilisĂ© entre deux valeurs sur lâabscisse en compressant les courbes des diffĂ©rentes couches, de façon Ă Ă©viter lâocclusion causĂ©e par le chevauchement des courbes. Plusieurs variantes tirant profit de ce concept ont Ă©tĂ© proposĂ©es et comparĂ©es Ă lâĂ©tat de lâart dans le cadre dâune Ă©valuation en laboratoire. Les rĂ©sultats ont dĂ©montrĂ© que les techniques de compression, et plus particuliĂšrement la technique superposĂ©e, permettaient dâeffectuer les tĂąches de façon plus prĂ©cise et avec un taux de succĂšs globalement supĂ©rieur par rapport Ă lâĂ©tat de lâart.
Enfin, le troisiĂšme projet tente dâadresser le problĂšme dâattribution de performances Ă grande Ă©chelle. Deux nouvelles techniques de visualisation, basĂ©es sur un graphique ternaire (ternary plot), ont Ă©tĂ© proposĂ©es afin de reprĂ©senter sur un seul graphique la relation entre le rendement diffĂ©rentiel avec la rĂ©fĂ©rence et les effets expliquant cette diffĂ©rence. Un systĂšme complet, sous la forme dâun tableau de bord intĂ©grant les visualisations proposĂ©es, a Ă©tĂ© dĂ©veloppĂ© et Ă©valuĂ© avec quatre experts du domaine dans un contexte rĂ©el dâanalyse. Les rĂ©sultats ont dĂ©montrĂ© que les outils proposĂ©s permettent dâanalyser un grand ensemble de portefeuilles, Ă diffĂ©rents niveaux, de façon simple et efficace. Les outils proposĂ©s rĂ©vĂšlent clairement les Ă©carts de performance, permettent dâidentifier facilement la source du problĂšme, et mĂȘme la stratĂ©gie globale utilisĂ©e par les gestionnaires de comptes auprĂšs de leurs clients et les comptes qui dĂ©vient de ces stratĂ©gies
Distributed force model for arbitrarily shaped IMPC actuators
A model that describes the relationship of an arbitrarily shaped artificial muscle to the force it produces does not currently exist for actuators made of ionic polymer-metal composites (IPMC), a type of electroactive smart material. The model in this thesis couples a finite element force simulation for IPMC with a novel method of performing force measurements for IPMC actuators. The model is capable of predicting the blocked force output for IPMC actuators of arbitrary dimension. The ultimate goal of this work is to create a method of analysis that allows for the design of custom IPMC fingers that have specific force production and actuation properties
NASA Tech Briefs, April 1997
Topics covered include: Video and Imaging; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Reports
Comparison of Regular Ringerâs Solution and Glucose Ringerâs Solution on the Longevity of the Hirudo medicinalisâ Retzius Cell
In 1882, Sydney Ringer, a professor of medicine at University College in London, experimented with the frog ventricle to better understand how each constituent of blood influences contraction. The ultimate goal was to create an artificial circulating fluid to use for the perfusion of isolated organs, in this case, a frog heart. Today, Ringerâs solution is still used in research for physiological studies requiring the survival and maintenance of specimens outside of their host bodies. One such example is the use of medicinal leech ganglia for electrophysiological measurements. In this thesis, I am comparing two Ringerâs solutions, original versus added glucose, and their impact on the longevity of the ganglia. By stimulating cells in the dissected ganglia submerged in Ringerâs solution with a micropipette, action potential responses can be recorded and used to compare longevity of the cells in each solution. By providing the dissected ganglia with an additional source of fuel, I hypothesized that cells in the glucose-enriched Ringerâs solution would live longer, and thus provide action potentials longer, than cells in regular Ringerâs solution with a minimum increase in longevity of thirty minutes. Data analysis showed that glucose Ringerâs solution did not keep the cells alive longer than regular Ringerâs solution when the difference of means was set to 30 minutes. However, data did show a significant difference in the average longevity of the Retzius cell in glucose Ringerâs solution versus regular Ringerâs solution when the difference of means was set to zero
NASA Tech Briefs, February 1991
Topics: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences
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