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  • 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.
61

Problematika pozorování objektů v dopravním zrcadle / Problem of Object Observation in Traffic Mirror

Adamec, Martin January 2013 (has links)
The thesis is written up within the master degree in field Expert engineering in transport. It follows up Problem of Object Observation in Traffic Mirror. Thesis describes the device of traffic mirror, physical principal, legislation and types of traffic mirrors in detail. There are measurements associated with this issue in practical part, which are evaluated in detail. At the conclusion there are suggested changes and recommendations associated with this issue.
62

Scanning Fabry-perot Spectrometer For Terahertz And Gigahertz Spectroscopy Using Dielectric Bragg Mirrors

Cleary, Justin 01 January 2007 (has links)
A scanning Fabry-Perot transmission filter composed of a pair of dielectric mirrors has been demonstrated at millimeter and sub-millimeter wavelengths. The mirrors are formed by alternating quarter-wave optical thicknesses of silicon and air in the usual Bragg configuration. Detailed theoretical considerations are presented for determining the optimum design including factors that affect achievable finesse. Fundamental loss by lattice and free carrier absorption are considered. High resistivity in the silicon layers was found important for achieving high transmittance and finesse, especially at the longer wavelengths. Also considered are technological factors such as surface roughness, bowing, and misalignment for various proposed manufacturing schemes. Characterization was performed at sub-mm wavelengths using a gas laser together with a Golay cell detector and at millimeter wavelengths using a backward wave oscillator and microwave power meter. A finesse value of 422 for a scanning Fabry-Perot cavity composed of three-period Bragg mirrors was experimentally demonstrated. Finesse values of several thousand are considered to be within reach. This suggests the possibility of a compact terahertz Fabry-Perot spectrometer that can operate in low resonance order to realize high free spectral range while simultaneously achieving a high spectral resolution. Such a device is directly suitable for airborne/satellite and man-portable sensing instrumentation.
63

Reakce sýkor koňader (Parus major) na obraz v zrcadle / Reactions of great tits (Parus major) to a mirror image

Forštová, Tereza January 2017 (has links)
Self-recognition is commonlly taken as a higher ability and it was previously considered to be exclusive to spieces who are cognitively more capable, as humans or apes. However during years other animal species with no expectancy of this ability were tested, such as elephants and cetaceans, and even there the signs of self-recognition were found. The most common test for self-recognition is the mark test. The animal is marked with none-olfactoric and none-tactile mark somewhere on the part of its body which can not be seen without mirror. If the subject recognizes itself in the mirror, it will try to wipe out the mark of its body with help of the mirror image. In our experiment we used great tit (Parus major) as a testing species and three types of mirror tests were carried our. Except the fact that great tits are able to succesfully learn to use the mirror image to search hidden food, we found no evidence of self-recognition in mark test. Therefore we believe that this passerine species is not capable of this type of self-recognition.
64

« Tromper les yeux ». Les miroirs dans le grand décor en Europe (XVIIe – XVIIIe siècles) / « Tromper les yeux ». Mirrors in the great decor in Europe (XVII-XVIII centuries)

Bazin-Henry, Sandra 19 November 2016 (has links)
Occupant une place majeure dans les intérieurs, les miroirs se sont progressivement imposés comme un décor d’architecture à part entière dans les pièces privées, puis dans les pièces de réception des grandes demeures aristocratiques européennes aux XVIIe et XVIIIe siècles. Le propos de la présente thèse est d’éclairer non seulement le développement des miroirs en tant que décoration fixe, mais aussi leur utilisation dans de véritables mises en scène architecturales. Envisagé sur un temps long de deux siècles et dans une aire géographique conséquente (France, Italie, Espagne, Allemagne, Autriche, Suède), ce travail débute par une étude du développement de ces décors au XVIIe siècle, en interrogeant le rôle de la France dans la définition et la circulation des modèles en Europe. Puis, dans un second temps sont étudiées les typologies de cabinet et de galerie de glaces, pièces les plus concernées par ce type de décor. Enfin, la place des miroirs dans la pratique architecturale et leur rôle illusionniste dans les intérieurs sont traités dans une dernière partie. / Occupying an important place in the interiors, mirrors have progressively been an architectural decor in its own right in the private rooms, then in the reception rooms of the European great aristocratic houses in the XVII and XVIII centuries. The purpose of this thesis is to enlighten not only the development of mirrors as fixed decoration, but also their use in true architectural staging. Based on a two century scale and a substantial geographic area (France, Italy, Spain, Germany, Austria, Sweden), this work starts by a study of the development of these decors in the XVII century, by questioning the role of France in the definition and the circulation of models in Europe. Then, it focuses on the typologies of mirror cabinet and galleries, the most affected rooms by this kind of décor. Finally, in the last section, the mirror place in the architectural practice and their illusionist role in the interiors are studied.
65

From Motion to Movements : Revelations by the Infant EEG

Nyström, Pär January 2008 (has links)
<p>The introduction of high density EEG (hd-EEG) nets for easy application on subjects of all ages has improved the possibilities to investigate the development of the infant neurophysiology. This dissertation consists of three studies (I – III) that investigate the visual motion system and mirror neuron system of the infant, and methodological sections that outline the bioelectrical background and the characteristics of the methods used. </p><p>Study I covers the maturation of cortical areas involved in motion perception in adults and infants using an ERP paradigm. Over three age groups (2, 3 and 5 month olds) the cortical activation increased dramatically. All infant groups showed significant activation when moving displays was contrasted to static displays on a video screen. The study shows that 5-month-old infants and older can be expected to process motion in a similar fashion as adults.</p><p>Study II covers the infant mirror neuron system (MNS). In adults the mu rhythm perturbations is considered a reliable measure of activation of the MNS. This study presented both a mu rhythm analysis and a ERP analysis to detect MNS activity in 6-month-olds and in adults. This study concludes that the infant MNS can be measured using ERPs and that the development of mu rhythm perturbations requires further study.</p><p>Study III focused on exploring the mu rhythm suppressions. 8-month-olds observed a live actor that performed goal directed reaches and non-goal directed hand movements. The results show robust mu rhythm perturbations time-locked to the grasping moment. The study concluded that the MNS activity is possible to evaluate by analysis of mu rhythm perturbations and that the MNS show mature characteristics at the age of 8 months.</p><p>In summary, Study 2 and 3 present new methods to investigate the infant mirror neuron system and shows that the infant MNS is active at 6 months of age. At 8 months of age the infant MNS show mature EEG responses to simple actions such as reaching. How the MNS development relates to the infants’ motor development, and how the MNS interacts with the development of social skills requires further studies that could benefit from the methods presented here.</p>
66

Laiko mašina magistro baigiamojo darbo aiškinamasis raštas / The Time Machine

Mikutavičius, Mantas 03 July 2014 (has links)
Laiko mašina Laiko mašina - neišrastas, bet kiekvieną dieną matomas daiktas - veidrodis. Matomas atspindys veikia pasamonę, o besikeičianti šviesa - apmąstymus: kas buvo lieka už nugaros, kas bus stovi prieš mus. Aš svajoju, žvelgiu į dangų, neišsipildžiusios svajonės žvelgiu žemyn. Lygiagrečiai susiduriame su kasdieniniais pasirinki-mais - kairė ar dešinė. O viso to centras esu AŠ. / The Time Machine The Time Machine - invented, but every day visible object - a mirror. Visible reflection does the subconscious mind and changing light - reflection: What has been left behind, who will be standing in front of us. I dream, I look at the sky, I look down unfulfilled dreams. In parallel, we encounter everyday-tion's choice - left or right. And all that I am the center.
67

LSST primary/tertiary monolithic mirror

Sebag, J., Gressler, W., Liang, M., Neill, D., Araujo-Hauck, C., Andrew, J., Angeli, G., Cho, M., Claver, C., Daruich, F., Gessner, C., Hileman, E., Krabbendam, V., Muller, G., Poczulp, G., Repp, R., Wiecha, O., Xin, B., Kenagy, K., Martin, H. M., Tuell, M. T., West, S. C. 08 August 2016 (has links)
At the core of the Large Synoptic Survey Telescope (LSST) three-mirror optical design is the primary/tertiary (M1M3) mirror that combines these two large mirrors onto one monolithic substrate. The M1M3 mirror was spin cast and polished at the Steward Observatory Mirror Lab at The University of Arizona (formerly SOML, now the Richard F. Caris Mirror Lab at the University of Arizona (RFCML)). Final acceptance of the mirror occurred during the year 2015 and the mirror is now in storage while the mirror cell assembly is being fabricated. The M1M3 mirror will be tested at RFCML after integration with its mirror cell before being shipped to Chile.
68

The Art of Optical Aberrations

Wylde, Clarissa Eileen Kenney, Wylde, Clarissa Eileen Kenney January 2017 (has links)
Art and optics are inseparable. Though seemingly opposite disciplines, the combination of art and optics has significantly impacted both culture and science as they are now known. As history has run its course, in the sciences, arts, and their fruitful combinations, optical aberrations have proved to be a problematic hindrance to progress. In an effort to eradicate aberrations the simple beauty of these aberrational forms has been labeled as undesirable and discarded. Here, rather than approach aberrations as erroneous, these beautiful forms are elevated to be the photographic subject in a new body of work, On the Bright Side. Though many recording methods could be utilized, this work was composed on classic, medium-format, photographic film using white-light, Michelson interferometry. The resulting images are both a representation of the true light rays that interacted on the distorted mirror surfaces (data) and the artist’s compositional eye for what parts of the interferogram are chosen and displayed. A detailed description of the captivating interdisciplinary procedure is documented and presented alongside the final artwork, CCD digital reference images, and deformable mirror contour maps. This alluring marriage between the arts and sciences opens up a heretofore minimally explored aspect of the inextricable art-optics connection. It additionally provides a fascinating new conversation on the importance of light and optics in photographic composition.
69

Modern technologies of fabrication and testing of large convex secondary mirrors

Oh, Chang Jin, Lowman, Andrew E., Dubin, Matt, Smith, Greg, Frater, Eric, Zhao, Chunyu, Burge, James H. 22 July 2016 (has links)
Modern large telescopes such as TAO, LSST, TMT and EELT require 0.9m-4m monolithic convex secondary mirrors. The fabrication and testing of these large convex secondary mirrors of astronomical telescopes is getting challenging as the aperture of the mirror is getting bigger. The biggest challenge to fabricate these large convex aspheric mirrors is to measure the surface figure to a few nanometers, while maintaining the testing and fabrication cycle to be efficient to minimize the downtime. For the last a couple of decades there was huge advancement in the metrology and fabrication of large aspheric secondary mirrors. College of Optical Sciences in the University Arizona developed a full fabrication and metrology process with extremely high accuracy and efficiency for manufacturing the large convex secondary mirrors. In this paper modern metrology systems including Swing-Arm Optical Coordinate Measuring System (SOCMM) which is comparable to Interferometry and a Sub-aperture stitching interferometry scalable to a several meters have been presented. Also a Computer Controlled Fabrication Process which produces extremely fine surface figure and finish has been demonstrated. These most recent development has been applied to the fabrication and testing of 0.9m aspheric convex secondary mirror for the Tokyo Atacama Observatory's 6.5m telescope and the result has been presented.
70

Alterações hemodinâmicas encefálicas no sistema de neurônios-espelho associados à imitação: um estudo envolvendo imageamento funcional por ressonância magnética / Imitation-related encephalic hemodynamic changes in the mirror neurons system: a study involving functional magnetic ressonance imaging

Lima, Renata Pereira 27 September 2011 (has links)
Neurônios espelho são ativados tanto durante a execução de uma ação como durante a observação desta mesma ação desempenhada por outra pessoa. Como parecem integrar observação e ação, os neurônios espelho têm sido foco de estudos sobre como o ser humano entende o próximo e em que extensão é capaz de compartilhar experiências. Esta integração inclui uma \"representação interna\" que envolve as mesmas estruturas nervosas envolvidas na execução da ação observada e tem sido sugerida como parte fundamental da facilitação do aprendizado por imitação. Este trabalho teve como objetivo, além de investigar o papel do sistema de neurônios-espelho no comportamento imitativo, investigar como ações motoras desconhecidas passam a ser reconhecidas e incorporadas ao repertório motor no contexto atual de neurônios espelho. Para isso, 20 voluntários foram treinados a executar acordes musicais em tarefas envolvendo imitação. Nossos resultados mostram que o sistema de neurônios-espelho possui um crítico papel durante a observação de uma ação com o intuito de imitá-la. Além disso, a ativação do sistema de neurônios-espelho pode ser alterada dependendo do contexto em que a ação está inserida / Mirror neurons are activated both during action execution and during observation of this same action performed by another person. As they seem to integrate observation and action, mirror neurons have been the focus of studies on how humans understand the other and to what extent is able to share experiences. This integration includes an \"internal representation\" that involves the same neural structures involved in the execution of an observed action and has been suggested as a fundamental part of the facilitation of learning by imitation. This study aimed, besides investigating the role of the mirror neuron system in imitative behavior, investigating how unknown motor actions are recognized and incorporated into the repertoire after practice in the current context of motor mirror neurons. For this, 20 volunteers were trained to perform tasks involving musical chords in imitation context. Our results show that the mirror neuron system has a critical role during the observation of an action in order to imitate it. Moreover, activation of mirror neuron system may be altered depending on the context in which the action is inserted

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