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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.
111

TRANSPORTATION OF THE RF SPECTRA OVER FIBER: A WORKING SYSTEM

Moore, Jeanne 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / This paper presents the results of installing a distributed feedback (DFB) laser transmitter and the appropriate optical receiver in an operational site. Frequencies from 1435 to 2400 megahertz are transported intact from a remote site to a local site. From the theoretical calculations, 10 dB of dynamic range may need to be recovered by the use of an automatic gain circuit. The actual device is a delight, needing no additional circuitry to meet specifications. Predictions of performance were made from calculations. The installed system was measured for 1 dB compression point and for figure of merit.
112

How do 5.5-month-old Infants Learn to Segment Objects from their Backgrounds?

Campbell, Elizabeth Marie Salvagio, Campbell, Elizabeth Marie Salvagio January 2017 (has links)
How do infants segment objects from the complex visual environment? Investigations of figure-ground perception have been dominated by studies assessing infants' sensitivity to depth and figure cues; few studies have assessed what information infants' use to perceive figures as separate from grounds. Research examining word segmentation suggests that statistical learning might aid segmentation in visual scenes. Despite the numerous studies investigating figure-ground segmentation, none have investigated the role of spatial transitional probabilities as a means for segmentation. To examine this question, we used a habituation/familiarity-preference procedure to assess whether background variability enables 5.5-month-old infants' perception of figures as separate from the background. The results of Experiments 1 and 2 indicated that statistical learning extends to scene segmentation, scene contexts allowed extraction of statistical distribution. Experiment 3 demonstrated that matching the configuration of visual arrays during training and test is essential; mismatched stimuli impede the measurement of segmentation.
113

Heart of Flesh

McSpadden, Joseph Aaron 01 January 2006 (has links)
In the past two years my paintings have fluctuated from figuration to abstraction. Dense surfaces, physical weight, and sense of touch have been dominant characteristics of my work. I have tried to animate oil paint by pushing it to the outer edges of the painting support and by using it to perform unorthodox tasks. I have stretched the limits of oil paint, creating works that reference flesh and the figure even while the forms remain amorphous and minimal. My work is a way for me to question the meaning of material and spiritual transformation.
114

Feet Touching the Floor

Lyon, Ashley 06 May 2011 (has links)
Realism, the uncanny, the figure, empathy, humanism, sculpture, feet, architecture, photography, oscillation, tin, installation, material, form, Herzog, projection, tactility, subject, haptics, sensibility, wax, portraits, space, embodied perception, rendering, duplication, thing, object, fragment, body, gaze, clay, god, man.
115

Specifické změny na nohách krasobruslařů a možnosti jejich fyzioterapeutického ovlivnění - literární rešerše / Specific foot changes in figure skaters and options for their physiotherapeutic intervention

Brabencová, Hana January 2012 (has links)
Title of diploma thesis: Specific foot changes in figure skaters and options for their physiotherapeutic intervention. Objective: The purpose of this thesis is to research available literary sources concerning anatomy, kinesiology and biomechanics of foot and foot arch in relation to specific foot changes resulting from figure skating. In addition, the thesis seeks to research various physiotherapeutic approaches which could be applied in prevention, compesation or therapy of these changes. Methods: This diploma thesis has descriptively-analytical character. It is structured in the form of literary research. Results: On the basis of the researched literary sources, this thesis provides a comprehensive picture on the topic of foot in figure skaters. Based on the research, the thesis identifies foot changes resulting from deformation of the foot in the skate. Subsequently, the thesis discussess the possible physiotherapeutic approaches which can be applied in prevention, compensation or therapy of these changes. Key words: foot, figure skating, flatfoot, physiotherapy
116

A behavioral task sets an upper bound on the time required to access object memories before object segregation

Sanguinetti, Joseph L., Peterson, Mary A. 22 December 2016 (has links)
Traditional theories of vision assume that object segregation occurs before access to object memories. Yet, behavioral evidence shows that familiar configuration is a prior for segregation, and electrophysiological experiments demonstrate these memories are accessed rapidly. A behavioral index of the speed of access is lacking, however. Here we asked how quickly behavior is influenced by object memories that are accessed in the course of object segregation. We investigated whether access to object memories on the groundside of a border can slow behavior during a rapid categorization task. Participants viewed two silhouettes that depicted a real-world and a novel object. Their task was to saccade toward the real-world object as quickly as possible. Half of the nontarget novel objects were ambiguous in that a portion of a real-world object was suggested, but not consciously perceived, on the groundside of their borders. The rest of the nontargets were unambiguous. We tested whether saccadic reaction times were perturbed by the real-world objects suggested on the groundside of ambiguous novel silhouettes. In Experiments 1 and 2, saccadic reaction times were slowed when nontargets were ambiguous rather than unambiguous. Experiment 2 set an upper limit of 190 ms on the time required for object memories in grounds to influence behavior. Experiment 3 ruled out factors that could have produced longer latencies other than access to object memories. These results provide the first behavioral index of how quickly memories of objects suggested in grounds can influence behavior, placing the upper limit at 190 ms.
117

Figural properties are prioritized for search under conditions of uncertainty: Setting boundary conditions on claims that figures automatically attract attention

Peterson, Mary A., Mojica, Andrew J., Salvagio, Elizabeth, Kimchi, Ruth 28 October 2016 (has links)
Nelson and Palmer (2007) concluded that figures/figural properties automatically attract attention, after they found that participants were faster to detect/discriminate targets appearing where a portion of a familiar object was suggested in an otherwise ambiguous display. We investigated whether these effects are truly automatic and whether they generalize to another figural property-convexity. We found that Nelson and Palmer's results do generalize to convexity, but only when participants are uncertain regarding when and where the target will appear. Dependence on uncertainty regarding target location/timing was also observed for familiarity. Thus, although we could replicate and extend Nelson and Palmer's results, our experiments showed that figures do not automatically draw attention. In addition, our research went beyond Nelson and Palmer's, in that we were able to separate figural properties from perceived figures. Because figural properties are regularities that predict where objects lie in the visual field, our results join other evidence that regularities in the environment can attract attention. More generally, our results are consistent with Bayesian theories in which priors are given more weight under conditions of uncertainty.
118

Instabilities of visual perception in the 'Bath Series' of Jasper Johns (1983-1988)

Smit, Susanna Margrietha 04 October 2012 (has links)
M.A.University of the Witwatersrand, Faculty of Humanities (Fine Arts), 2012 / The ‘Bath Series’ (1983-1988) of Jasper Johns shows the artist’s meditation on his oeuvre of the past thirty years, and the examples of his previous works demonstrate his interest in instabilities of visual perception. The latter are activated when the viewer’s expectation to see conventional representational strategies are destabilized, and figure/ground pictorial space, particularly, becomes ambiguous. This first recorded academic study focusing exclusively on the series as a unit, discovers that figure/ground switching, an ‘Ur-Gestalt’ (Gandelman 1989: 209), appears to be a core energy motivating ambiguous pictorial space in Johns’ art, and constitutes the theoretical component of the research. The practical component is a site specific installation which shows some visual and verbal processes and meditates on the perpetual interaction between the eye and the mind, which is a fundamental concern of Johns (Varnedoe 1996b: 245, 257), as well as of myself. The work invites viewers to experience destabilized conventional visual perceptions and to explore, as Johns said, ‘something new’ (Varnedoe 1996a: 17).
119

Thermoelectric Properties of CoSb3-Based Skutterudites

Yang, Jian January 2010 (has links)
Thesis advisor: Zhifeng Ren / Solid state cooling and power generation based on thermoelectric principles are regarded as one of the technologies with the potential of solving the current energy crisis. Thermoelectric devices could be widely used in waste heat recovery, small scale power generation and refrigeration. It has no moving parts and is environmental friendly. The limitation to its application is due to its low efficiency. Most of the current commercialized thermoelectric materials have figure of merit (ZT) around 1. To be comparable with kitchen refrigerator, ZT is required at room temperature. Skutterudites have emerged as member of the novel materials, which potentially have a higher ZT. In the dissertation, my investigation will be focused on the optimization of CoSb<sub>3</sub> &ndash based skutterudites. Starting with Co and Sb elements, CoSb<sub>3</sub> will form through a high energy ball mill. Unfortunately, even after 20 hours, only a small percentage of the powders have transformed in into CoSb<sub>3</sub>. Then the powders will be compacted into bulk samples by DC-controlled hot press. CoSb<sub>3</sub> single phase will form after press. Characterization of the structure and thermoelectric properties will be presented with details. The effects of synthesis conditions on thermoelectric properties of skutterudites were studied and discussed. Several possible methods of improving the ZT of N type skutterudites were applied. The highest obtained ZT thus far is about 1.2 from Yb doped CoSb<sub>3</sub>. For a group of samples with nominal composition Yb<sub>x</sub>Co<sub>4</sub>Sb<sub>12</sub>, the increased Yb concentration in our samples not only enhanced the power factor due to electron doping effect but also decreased the thermal conductivity due to a stronger rattling effect. In addition, the increased grain boundary density per unit volume due to the small grains in our bulk skutterudite materials may have also helped to enhance the phonon scattering and thus to reduce the thermal conductivity. Single and double doping methods with different combinations were also tried. So far, none of them have surpassed ZT of 1.2. Mixing different materials with Yb<sub>0.35</sub>Co<sub>4</sub>Sb<sub>12</sub> so far to increase the phonon scattering was also performed. No dramatic thermal conductivity reduction was observed. Small amounts of Fe/Mn substitution on Co sites will decrease the power factor to undesired degrees. Some results with Nd filled P type sample will be briefly introduced. P type samples are also obtained through substitution on Sb site. Preliminary work on preparing the electrode for CoSb<sub>3</sub> will be presented in the dissertation. CoSi<sub>2</sub> has low resistivity, and a similar coefficient of thermal expansion (CTE) as of doped CoSb<sub>3</sub>. It is good electrode candidate. DC controlled hot press is used to make the contact. Thermal stability of the contact was tested. Small cracks will form in the contact area, further improvement is necessary. Finally, my previous work on ZnO nanowire growth is briefly introduced. Large throughput of ZnO nanowire could be obtained with NaCl as the support to promote the conversion of Zn powder to ZnO. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.
120

Act as Attribute: The Attacking Body in Ancient Greek Art

Peebles, Matthew January 2019 (has links)
An image of the body in the act of attack might be taken as an inherently episodic or narrative motif, due to the apparently transitive nature of the movement involved. Such a categorization is challenged, however, by an array of ancient Greek images that distance the attacking figure from a temporal context, as by the elision of an explicit victim; such images betray the attacking body’s “iconic” aspect, which is underlain by the efficient communication of symbolic values linked to the identity of the subject. This dissertation surveys the development of the iconic motif of the attacking body across diverse media, from its cross-cultural origins in the Bronze Age to its reformulations in the Archaic, Classical, and Hellenistic eras. In doing so, it tracks the codification of value-rich attacking “schemata” (recurring poses) in the representation of particular identities, including warriors, athletes, and various divinities, among others. Integrating the social-symbolic model of gesture and the body that has emerged across academic disciplines with a generally (though not exclusively) semiotic approach to the ancient imagery, the study elucidates key continuities in the significance of the motif as it appears in multiple forms and across an intriguing range of iconographic and functional contexts. Ultimately, it builds an argument that in a society in which the exertion of violence was central to the performance of status and the construction of power, the visual motif of the attacking body was critically linked to the figuration of human and divine identity: the “act as attribute.”

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