• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 62
  • 25
  • 11
  • 10
  • 7
  • 7
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 143
  • 21
  • 18
  • 16
  • 15
  • 14
  • 14
  • 13
  • 13
  • 12
  • 12
  • 10
  • 10
  • 10
  • 10
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Multichannel EEG Signal Classification -A Geometric Approach

Li, Yili 09 1900 (has links)
<p> The study of the different sleep stages of a patient using his/her recorded EEG signals falls in the area of signal classification. In general, this involves extracting from the EEG signals, a signal feature on which the classification is performed. In this thesis, we apply the techniques of signal classification to the analysis of the sleep of a patient. The feature we use is the power spectral density (PSD) matrices of a multi-channel EEG signal. This not only allows us to examine the power spectrum contents of each signal which complies with what clinical experts use in their visual judgement of EEG signals, but also allows the correlation between the multi-channel signals to be studied. To establish a metric facilitating the classification, we analyze the structure as well as exploit the specific geometric properties of the space of PSD matrices. Specifically, we study this space from the viewpoint of Riemannian manifolds. We apply a Riemannian metric and, with the aid of fibre bundle theory, develop intrinsic (geodesic) distance measures for the PSD matrix manifold. To utilize such new distance measures effectively for EEG signal classification, we need to find a suitable weighting matrix for the PSD matrices so that the distances between similar features are minimized while those between dissimilar features are maximized. A closed form expression for this weighting matrix is obtained by solving an equivalent convex optimization problem. The effectiveness of using these novel weighted distance measures is verified by applying them to the sleep pattern classification of a collection of recorded EEG signals using the k-nearest neighbor decision algorithm with excellent results. </p> / Thesis / Doctor of Philosophy (PhD)
12

Comparison of the Different Hazards Experienced by Pallets During Material Handling

Sabattus, William Joseph-Clark 23 February 2023 (has links)
Pallets play a crucial role in the supply chain with approximately 2.6 billion in circulation in the United States alone. Although often overlooked, pallets can become costly for a company if not designed correctly for their specific supply chain. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. Forklifts are the dominant mode of material handling for palletized products, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic nature of forklifts in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert during material handling. Forklifts in multiple facilities were instrumented with Lansmont SAVER 3X90 and 3D15 data loggers to measure the acceleration peak, g of shock impacts, duration of impacts, random vibration intensity and RMS (g) values during forklift handling in the field. The highest vibration levels were observed for distribution facilities with an average acceleration (peak, g) of 0.353 g. Based on the results of the vibration data collection, the vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that LTL facilities recorded the highest average shock impact of all the facilities investigated, with an average acceleration value of 4.74 g with an average shock duration of 7.42 msec. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains. / Master of Science / With 2.6 billion pallets in circulation within the United States alone, pallets play a significant role in the supply chain. Pallets can become costly for a company if not designed correctly for their specific supply chain, so it is important not to overlook a pallet. Durability is an essential characteristic of pallets; it defines the expected life of the pallet in the supply chain. The forklift is the most common mode of material handling for the transportation of palletized products within a warehousing system, and they are responsible for the majority of damages experienced by pallets. Despite the prominence of forklifts in the supply chain and their importance in pallet design, there is a lack of research focusing on the dynamic shock and vibration characteristics that forklifts experience in the field. The objective of this research paper was to investigate the intensity of the vibrations and shock impacts that forklifts exert on pallets during material handling. Forklifts in multiple facilities were instrumented with Lansmont data loggers to measure the dynamic characteristics of both shock and vibration in the field. The highest vibration levels were observed for distribution facilities. Based on the results of the vibration data collection, a vibration profile for laboratory simulation was proposed. The results of the shock measurement showed that Less-than-Truckload (LTL) facilities recorded the highest average shock impact of all the facilities investigated. The intensity of shock events measured during the FasTrack procedure was slightly greater than what was observed for the LTL facility indicating that the FasTrack simulation is slightly harsher than the field handling of pallets. Based on the results of the shock measurement, new intensity levels were recommended for the incline impact test to better represent the harshness of handling in the field. The results of this study will be used to revise the durability testing procedures used in pallet testing standards in order to better represent the current material handling processes found in modern supply chains.
13

Analyses du comportement de rupteurs thermiques sous sollicitations sismiques / Behavior of thermal breaks under seismic loads

Nguyen, Thi Thanh Huyen 06 March 2012 (has links)
Compte tenu des attentes en termes de développements durables, de nouvelles solutions technologiques sont adoptées dans les bâtiments à basse consommation énergétique permettant de réduire considérablement les déperditions par ponts thermiques. Il s’agit des rupteurs thermiques, nouvelles jonctions entre porteurs verticaux et horizontaux constituées de matériaux innovants. Parallèlement à l’évolution des réglementations thermiques dans les bâtiments, la nouvelle définition de l’aléa sismique en France oblige les concepteurs à intégrer le cas de chargement sismique dans les dimensionnements de bâtiments dans une grande majorité du territoire métropolitain. Ces innovations technologiques nécessitent donc des études approfondies de leur comportement mécanique lors d’événements accidentels tels que les tremblements de terre. Au regard des enjeux sociétaux et économiques, il est d’une grande importance d’être capable d’apprécier la contribution de nouvelles solutions techniques à la vulnérabilité du bâti aux séismes. Pour cela, il est nécessaire de procéder à des analyses probabilistes pour la construction, par exemple de courbes de fragilité de structures sous sollicitations sismiques: structures étant composées ou non de rupteurs thermiques. L’objectif de ce travail est donc de proposer l’ensemble d’une méthodologie notamment les outils numériques, en termes de modèles mécaniques, susceptibles de répondre aux attentes de l’ingénierie dans la quantification de l’évolution des marges de résistance en intégrant différents types de rupteurs thermiques dans les bâtiments. Pour cela, différentes étapes, combinant modélisations numériques et expérimentations sont abordées afin d’élaborer un modèle numérique simplifié. Ce dernier doit être riche en termes de phénomènes mécaniques et efficace numériquement pour réaliser rapidement un nombre important de calculs nonlinéaires à l’échelle de bâtiment en tenant compte des aspects aléatoires. / Nowadays sustainable constructions imply an objective of energetic performances by reducing the level of thermal conduction. The thermal-break elements, an innovative technological element is under study in several countries in Europe. If the thermal benefits have already been proved, the mechanical effects of such a wall-slab connection in a building for the seismic risk have not been assessed. To evaluate the building seismic vulnerability modifications due to these thermal breaks, experimental and numerical developments have to be performed. An experimental campaign is proposed to evaluate the seismic ability of such structural elements and a simplified modelling is proposed aiming at developing numerical framework able to handle parametrical and probabilistic approaches for structural analysis. This model is also validated in dynamic case by using the Pseudodynamic testing.
14

The role of DLG-MAGUKs in mediating signaling specificity at the postsynaptic density

Duda, Joana-Kristin 18 December 2018 (has links)
No description available.
15

Criação de “novos” partidos no Brasil contemporâneo: os casos do PSOL e do PSD

Alves, Breno Alexandre Pires Fernandes 18 May 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-08-03T19:32:15Z No. of bitstreams: 1 brenoalexandrepiresfernandesalves.pdf: 1661658 bytes, checksum: fd06e144034b11d8e10b9abd00c8f0f9 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-08-28T13:34:54Z (GMT) No. of bitstreams: 1 brenoalexandrepiresfernandesalves.pdf: 1661658 bytes, checksum: fd06e144034b11d8e10b9abd00c8f0f9 (MD5) / Made available in DSpace on 2018-08-28T13:34:54Z (GMT). No. of bitstreams: 1 brenoalexandrepiresfernandesalves.pdf: 1661658 bytes, checksum: fd06e144034b11d8e10b9abd00c8f0f9 (MD5) Previous issue date: 2018-05-18 / A presente dissertação tem por objetivo comparar a criação e o desenvolvimento do Partido Socialismo e Liberdade (PSOL) e do Partido Social Democrático (PSD). Partimos da premissa de que a origem dos partidos apresenta forte influencia sobre seu desenvolvimento futuro, bem como suas estratégias e objetivos. Portanto, a análise se dá a partir da comparação da criação desses novos partidos (PSOL e PSD), de seus primeiros membros, de suas estruturas organizacionais, de seus filiados, de suas estratégias e de seu desempenho ao longo das eleições que disputaram. Como análise complementar, buscamos observar as características que possam nos revelar o quanto de novidade esses partidos oferecem ao sistema político e partidário brasileiro. Ao explorar esses aspectos, ressaltando as diferenças e semelhanças entre os partidos em questão, esperamos auxiliar na compreensão de como o mesmo arranjo político pode ser um campo frutífero para o desenvolvimento de partidos que, aparentemente, apresentam características distintas. / This thesis aims to compare the birthand the development of the PartidoSocialismo e Liberdade (PSOL) and the Partido Social Democrático (PSD). Our research has as a starting point the premise that the origin of these parties contains a substantial influence upon their unfolding and their strategies and objectives. Therefore, our analysis proposes a comparison between not only the creation of these two new parties (PSOL e PSD), but also between their first members, their structural organization, the people enrolled in them, the strategies used by them, and theirperformance during the elections in which they participated. As a complementary analysis, we try to determine the elements that may reveal how much newness these parties offer to the Brazilian political and party systems. By exploring these aspects, highlighting the differences and similarities between these two parties, we hope to contribute to the understanding of how the same political arrangement can be a fecund domain to the development of parties that apparently show distinctive features.
16

The role of postsynaptic density (PSD) proteins PSD-95 and PSD-93 for mouse visual cortical plasticity and vision

Stodieck, Sophia Katharina 26 September 2016 (has links)
No description available.
17

SW simulátor analogových soustav / Analog system SW simulator

Košta, Ondřej January 2012 (has links)
This Master’s Thesis focuses on development and realization of analog system software simulator for simulation of various kinds and orders systems and for function verification of microcontrollers’ control systems. The development and realization of PSD controller is part of this thesis as well. The simulator is written in C++/CLI programming language which combines fast execution of native code and provides an advantage of managed code which has its execution managed by the .NET Framework. The data acquisition is performed via National Instrument’s USB multifunctional DAQ. The PSD regulator is realized by using modern ARM processor architecture.
18

Průmyslový PSD regulátor / Industrial PSD controller

Pelikán, Leoš January 2012 (has links)
This master’s thesis deal with principles temperature measurement using resistive temperature sensor PT100 and algorithm design PSD controler. In Work is includ description problems temperature measurement and way evaluation by means of mikrokontroler, which by PWM output controls supplied heat power. Next is here described method realization controls device for heating electric furnace with setup via Ethernet.
19

Ultrasound Hardware Setup For CMP Pad Characterization

Tadi, Bhaskar Vijay Kumar Reddy 30 March 2004 (has links)
Chemical Mechanical Polishing, (CMP), pads made of polyurethane material are utilized in the Integrated Circuit, (IC), industry to planarize wafers between successive process steps. The properties of such pads and their behavior must be known in order to determine under what conditions and for how long they can be used efficiently. This research involved the development of a system to study the properties of such pads. The system developed during this research enabled the pads to be tested under varying physical conditions. The setup used a combination of several instruments to provide excitation to the pad and acquire a measure its response. A central computer controlled the instrumentation system employed. In this research the determination of the physical properties of CMP pads was accomplished through the use of Ultra Sound testing. Ultra sound methods offer a non-destructive method of characterizing pads to be used in the production of IC wafers. Ultra sound characterization is currently one of the most widely used techniques utilized for non-destructive inspection. This report provides a detailed account of the hardware instruments involved and the method of integration of those instruments into a system that could easily, rapidly and accurately characterize CMP pads. The pad response was measured in terms of the signal voltage transmitted through the pad to the ultrasound sensor. The software stored these readings for every set of testing conditions. Changing the temperature, humidity and depth from the pad's surface where measurements are made changed the test conditions. These data were analyzed statistically to determine the behavior of the pad. This research was part of a larger research effort that provided the statistical tool required to determine the uniformity of a CMP pad.
20

Digital Implementation of a Laser Doppler Perfusion Monitor

Larsson, Ola January 2006 (has links)
<p>Under 20 års tid har Perimed AB utvecklat och tillverkat LDPM- och LDPI-instrument som är baserade på en analog filterkonstruktion. De analoga komponenterna i konstruktionen är komplexa och icke-linjära med hänsyn till frekvens och de driver även med temperaturen. Funktionen hos konstruktionen beror också kraftigt av att de analoga komponenterna trimmas in under produktionen.</p><p>Det här examensarbetet syftar till att ta fram en alternativ design baserad kring en digital signal processor. Den digitala signalbehandlingsmetod som beskrivs baseras på väl förankrade laser-Doppler perfusionsteorier. Den implementerade signalbehandlingsalgoritmen beräknar perfusionen ur en samplad fotodetektorström, som har filtrerats till AC- och DC-komponenter med hjälp av ett analogt detektorkort. Algoritmen producerar en råperfusionssignal genom att beräkna en frekvensviktad summa av fotodetektorströmmens effektspektrum. Kompensation för detektorns brus och normalisering med ljusintensitet har också implementerats.</p><p>Den presenterade implementationen har verifierats mot ett exemplar av LDPM-enheten PF 5010 som har använts som referensinstrument vid alla mätningar. Mätningar in vitro har påvisat liknande mätresultat som referensinstrumentet för en referensvätska med hög perfusion och även för ett statiskt mätobjekt. Vidare har implementationen verifierats med mätningar in vivo på hud, vilket har påvisat nära nog identiska signalnivåer och gensvar på värmeprovokationer som referensinstrumentet.</p><p>Den demonstrerade uppfinningen förenklar tillverkningen av instrumenten eftersom antalet komponenter reduceras avsevärt och därmed antalet produktionstester. Användandet av en DSP reducerar dessutom instrumentets temperaturkänslighet eftersom den ersätter flera temperaturkänsliga komponenter.</p> / <p>For 20 years Perimed AB have been developing and manufacturing LDPM and LDPI instruments based on an analog filter construction. The analog components in the construction are complex and suffer from non-linear frequency dependency and temperature drifts. The functionality of the design is also heavily depending on analog components which need to be trimmed in the production.</p><p>In this thesis, an alternative design employing a digital signal processor is presented. The signal processing method used is based on well established laser Doppler perfusion theories. The implemented signal processing algorithm calculates the perfusion from a sampled photodetector current, pre-filtered into AC and DC components by an analog detector card. The algorithm produces a raw perfusion signal by calculating a frequency weighted sum of the power spectral density, PSD, of the photocurrent. Detector noise compensation and light intensity normalization of the signal has also been implemented.</p><p>The presented digital implementation has been verified using the PF 5010 LDPM unit as a reference. In vitro measurements have shown similar behaviour as the reference in a highly perfused reference fluid as well as for a static scatterer. Furthermore, the DSP implementation has been verified on in vivo measurements of skin, showing nearly identical signal levels and response to heat provocation as the reference.</p><p>The demonstrated invention improves the manufacturability of the instruments since it reduces the number of electronic components significantly and thus, the amount of manufacturing tests. The DSP also reduces the temperature sensitivity of the instrument since it replaces several analog components sensitive to temperature changes.</p>

Page generated in 0.0544 seconds