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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.
121

Image Quality and Radiation Dose Comparison of a Computed Radiography System and an Amorphous Silicon Flat Panel System in Paediatric Radiography: A Phantom Study

Irvine, Michael Alan, thebovus@yahoo.com January 2009 (has links)
This purpose of this work was to investigate the patient radiation doses and image quality of a Philips/Agfa computed radiographic (CR) system and a Philips indirect-capture digital radiographic (DR) system in a paediatric setting. A CDRAD digital radiographic contrast-detail phantom was used to assess radiographic image quality. Perspex slabs of three different thicknesses (6, 11 and 16 cm) were used to simulate paediatric patients of three arbitrary ages. These phantoms, in conjunction with the CDRAD digital radiographic contrast-detail phantom, were imaged under three different conditions. The CDRAD Analyser software package was used to assess the quality of each image. The first experiment conducted was a comparison of the two systems under standard conditions, with beam filtration of aluminium and copper, as recommended in European Guidelines on Quality Criteria for Diagnostic Radiographic Images in Paediatrics (European Commission 1996b). Image quality was compared for each phantom size at three doses with the same entrance exposure used for both systems. A visual comparison of the resulting contrast detail curves showed the DR system generally outperformed the CR system, especially at the lowest two doses. A chi-square analysis of the targets detected generally confirmed this visual impression. The second experiment performed was to compare the two systems under the conditions used in routine clinical practice at PMH. As a result of additional beam filtration not generally being employed, the image quality of the CR system was similar to the DR system for the two smaller phantom sizes but with a major dose cost - effective doses higher by between 38% and 100%. A chi-square analysis of the targets detected showed the CR system to be significantly better than the DR system at two of three doses for the thinnest phantom and no significant difference at any doses for the intermediate phantom size. For the largest phantom size, additional filtration - although different - was used for the CR and DR systems and so the X-ray beam spectra were more similar. Consequently, the results for this phantom size reflected those from the experiment conducted under standard conditions, ie the effective doses for both systems were similar and the image quality of the DR system superior. The chi-square analysis s howed the DR system to be significantly better than the CR at all three dose levels. A third experiment was undertaken to compare doses between the two systems at 'equal' image quality. The CDRAD Analyser software specific image quality parameter, IQFinv, was held constant for both systems. The entrance exposures required to achieve this image quality were measured and then converted to effective doses using the dose calculation software package PCXMC 1.5. The DR system offered effective dose savings of between 28 and 42% for the three phantom sizes. Overall, this work suggests that a Philips flat-panel system is superior to an Agfa CR system in paediatric radiography. This result generally reflects the findings of other authors who have conducted similar studies in adult patient settings.
122

Femme fantôme Poetologien und Szenen der Wiedergängerin um 1800/1900

Schumacher, Katrin January 2005 (has links)
Zugl.: Hamburg, Univ., Diss., 2005
123

Ghostly alterities : spectrality and contemporary literatures in English /

Del Villano, Bianca. January 2007 (has links)
Zugl.: Turin, University, Diss.
124

Η εντατική περιεγχειρητική αναλγησία μειώνει την ένταση, την επίπτωση και τη συχνότητα του πόνου φάντασμα μετά από ακρωτηριασμό κάτω άκρου : μια προοπτική, τυχαιοποιημένη, διπλή τυφλή κλινική μελέτη / Optimized perioperative analgesia reduces chronic phantom limb pain intensity, prevalence and frequency : a prospective, randomized, clinical trial

Αρέθα, Διαμάντω 10 August 2011 (has links)
Η παρουσία σοβαρού ισχαιμικού πόνου πριν από τον ακρωτηριασμό κάτω άκρου πολύ συχνά συνοδεύεται από την ανάπτυξη πόνου φάντασμα. Ερευνήσαμε αν η εντατική περιεγχειρητική αναλγησία μειώνει την ανάπτυξη πόνου φάντασμα 6 μήνες μετά τον ακρωτηριασμό. Μεθοδολογία: Σε συνολικά 65 ασθενείς πραγματοποιήθηκε προγραμματισμένος ακρωτηριασμός κάτω άκρου. Οι ασθενείς τυχαιοποιήθηκαν σε 5 ομάδες αναλγησίας: (1) Οι ασθενείς της ομάδας Επι/Επι/Επι έλαβαν περιεγχειρητικά επισκληρίδια αναλγησία και επισκληρίδιο αναισθησία; (2) Οι ασθενείς της ομάδας PCA/Επι/Επι έλαβαν προεγχειρητικά ενδοφλέβια αναλγησία ελεγχόμενη από τον ασθενή (Patient Controlled Analgesia-PCA), μετεγχειρητικά επισκληρίδιο αναλγησία και επισκηρίδιο αναισθησία; (3) Οι ασθενείς της ομάδας PCA/Επι/PCA έλαβαν περιεγχειρητικά ενδοφλέβια PCA και επισκληρίδιο αναισθησία; (4) Οι ασθενείς της ομάδας PCA/ΓΑ/PCA έλαβαν περιεγχειρητικά ενδοφλέβια PCA και γενική αναισθησία (ΓΑ); (5) Οι ασθενείς της ομάδας ελέγχου έλαβαν συμβατική αναλγησία και ΓΑ. Η επισκηρίδιος αναλγησία ή η ενδοφλέβια PCA ξεκινούσε 48 ώρες προεγχειρητικά και συνεχιζόταν για 48 ώρες μετεγχειρητικά. Τα αποτελέσματα της κλίμακας πόνου VAS (Visual Analogue Scale) και της κλίμακας πόνου McGill καταγραφόταν περιεγχειρητικά και στον 1 και 6 μήνες. Αποτελέσματα: Στους 6 μήνες, η ενδιάμεσες (median) τιμές (ελάχιστη-μέγιστη, minimum–maximum) του πόνου φάντασμα (Phantom Limb Pain – PLP) και οι τιμές P (ομάδες παρέμβασης έναντι ομάδας ελέγχου) για την κλίμακα πόνου VAS (Visual Analogue Scale) ήταν οι ακόλουθες: 0 (0–20) για την ομάδα Επι/Επι/Επι (P = 0.001), 0 (0–42) για την ομάδα PCA/Επι/Επι (P = 0.014), 20 (0–40) για την ομάδα PCA/Επι/PCA (P = 0.532), 0 (0–30) για την ομάδα PCA/ΓΑ/ PCA (P = 0.008), και 20 (0–58) για την ομάδα ελέγχου. Οι τιμές για την κλίμακα πόνου McGill (McGill Pain Questionnaire) ήταν οι ακόλουθες: 0 (0–7) για την ομάδα Επι/Επι/Επι (P = 0.001), 0 (0–9) για την ομάδα PCA/Επι/Επι (P = 0.003), 6 (0–11) για την ομάδα PCA/Επι/PCA (P = 0.208), 0 (0–9) για την ομάδα PCA/ΓΑ/PCA (P = 0.003), και 7 (0–15) για την ομάδα ελέγχου. Στους 6 μήνες πόνος φάντασμα παρουσιάστηκε σε 1 από τους 13 ασθενείς της ομάδας Επι/Επι/Επι, σε 4 από τους 13 ασθενείς της ομάδας PCA/Επι/Επι, και σε 3 από τους 13 ασθενείς της ομάδας PCA/ΓΑ/PCA έναντι 9 από τους 12 ασθενείς της ομάδας ελέγχου (P=0.001, P=0.027, και P=0.009, αντίστοιχα). Ο πόνος κολοβώματος στους 6 μήνες ήταν ασήμαντος. Συμπεράσματα: Η χρήση εντατικήςς αναλγησίας, με χρήση επισκληριδίου ή ενδοφλέβιας PCA, η οποία ξεκινάει 48 ώρες προεγχειρητικά και συνεχίζεται για 48 ώρες μετεγχειρητικά, μειώνει τον πόνο φάντασμα στους 6 μήνες. Trial registration: Clinical Trials.gov, number NCT00443404 / Severe preamputation pain is associated with phantom limb pain (PLP) development in limb amputees. We investigated whether optimized perioperative analgesia reduces PLP at 6-month follow-up. Methods: A total of 65 patients underwent lower-limb amputation and were assigned to five analgesic regimens: (1) Epi/Epi/Epi patients received perioperative epidural analgesia and epidural anesthesia; (2) PCA/Epi/Epi patients received preoperative intravenous patient-controlled analgesia (PCA), postoperative epidural analgesia, and epidural anesthesia; (3) PCA/Epi/PCA patients received perioperative intravenous PCA and epidural anesthesia; (4) PCA/GA/PCA patients received perioperative intravenous PCA and general anesthesia (GA); (5) controls received conventional analgesia and GA. Epidural analgesia or intravenous PCA started 48 h preoperatively and continued 48 h postoperatively. The results of the visual analog scale and the McGill Pain Questionnaire were recorded perioperatively and at 1 and 6 months. Results: At 6 months, median (minimum–maximum) PLP and P values (intervention groups vs. control group) for the visual analog scale were as follows: 0 (0–20) for Epi/Epi/Epi (P _ 0.001), 0 (0–42) for PCA/Epi/Epi (P = 0.014), 20 (0–40) for PCA/Epi/PCA (P = 0.532), 0 (0–30) for PCA/GA/ PCA (P = 0.008), and 20 (0–58) for controls. The values for the McGill Pain Questionnaire were as follows: 0 (0–7) for Epi/Epi/Epi (P = 0.001), 0 (0–9) for PCA/Epi/Epi (P = 0.003), 6 (0–11) for PCA/Epi/PCA (P = 0.208), 0 (0–9) for PCA/GA/PCA (P = 0.003), and 7 (0–15) for controls. At 6 months, PLP was present in 1 of 13 Epi/Epi/Epi, 4 of 13 PCA/Epi/Epi, and 3 of 13 PCA/GA/PCA patients versus 9 of 12 control patients (P=0.001, P=0.027, and P=0.009, respectively). Residual limb pain at 6 months was insignificant. Conclusions: Optimized epidural analgesia or intravenous PCA, starting 48 h preoperatively and continuing for 48 h postoperatively, decreases PLP at 6 months. Trial registration: Clinical Trials.gov, number NCT00443404
125

Selected topics on the neuroscience of altered perceptions and illusory beliefs

Roth, Alexander Sebastian 24 July 2018 (has links)
Six neuropsychological topics illustrating altered perceptions and illusory beliefs are explored with particular emphasis on the neurobiological underpinnings of such phenomena. The first five topics are phantom limb, out-of-body experiences including depersonalization and near-death experiences, delusions with an emphasis on the effects of psychedelic drugs, autonomic reflex actions including respiration and heartbeat, and virtual reality. The last topic focuses on three disorders impairing perception and cognition, namely, Anton-Babinski, Charles Bonnet, and Diogenes Syndromes. Many of the related neurobiological mechanisms reflect disturbances of both lower-level and multisensory processing along with specific cortical impairments such as at the temporoparietal junction. The latter has been linked, for example, to out-of-body experiences. Similarly, aberrant neural learning and signaling such as that based on synaptic receptor disturbances show how the interplay between lower-level brain activity and that in the prefrontal cortex contributes to delusions. Specific hypotheses set forth to explain these alterations in perception and cognition are reviewed, such as a remapping theory which depicts cortical reorganization in response to synaptic changes mediated by receptors. The effects of these perceptual/cognitive distortions on experiential pleasure/pain and on adaptability are also explored.
126

Estudo da taxa de absorção específica e análise de dosimetria em protótipos de óculos e fone de ouvido para dispositivos de comunicação operando próximo da cabeça do usuário

Álvarez Pizarro, Yuli Andrea January 2015 (has links)
Dois dispositivos de comunicação sem fio populares são considerados nesta pesquisa. Em primeiro lugar, o fone de ouvido que utiliza tecnologia Bluetooth, sendo um dos acessórios móveis mais econômicos do mercado e os óculos para dispositivos de comunicação que são uma representação da nova visão futurista. A absorção de ondas eletromagnéticas na cabeça humana durante um certo período de tempo, pode conduzir a problemas de saúde. A Taxa de Absorção Específica (SAR) foi simulada em quatro modelos diferentes para duas abordagens que realizam variações nos parâmetros dielétricos dos tecidos da cabeça. Estes resultados foram comparados com as recomendações internacionais (IEC 62209-2, 2010; ICNIRP, 2009; IEEE C95.1,2005; WHO, 2006; IEEE, 2002). O primeiro modelo utilizado foi o Manequim Antropomórfico Específico (SAM phantom), bem como três modelos realistas de cabeça humana (ou seja, um adulto de 34 anos e duas crianças de 10 e 6 anos). As simulações foram executadas utilizando o método de diferenças finitas (FDTD) e a frequência usada para alimentar as antenas foi de 2,45 GHz. Além disso foram feitas medidas experimentais de potência transmitida pelo dispositivo Bluetooth. / Two popular wireless communication devices are considered in this research. Firstly, the handset Bluetooth which is one of the most economic mobile accessories and the eyewear Communicating Device which are a representation of the new futuristic vision. It is well known that the absorption of electromagnetic waves on the human head for a certain period of time may lead to health problems such as headaches. The Specific Absorption Rate (SAR) is simulated to four different head models for two approaches that perform variations in the dielectric parameters in the head tissues and compared with the available international recommendations (IEC 62209-2, 2010; ICNIRP, 2009; IEEE C95.1,2005; WHO, 2006; IEEE, 2002). The first model used is the Specific Anthropomorphic Mannequin (SAM phantom), as well as three realistic models of human head (i.e., a 34 years old adult and two children of 10 and 6 years old). The simulations were performed using the finite difference time domain (FDTD) method and the frequency used to feed the antennas was 2.45 GHz. Experimental measurements of transmission power in Bluetooth device are also described.
127

La poesia di Andrea Zanzotto e il registro lacaniano del reale / La poésie d’Andrea Zanzotto et le registre lacanien du réel / The poetry of Andrea Zanzotto and the lacanian register of the real

Russo, Alberto 11 February 2017 (has links)
Cette recherche se propose de réaliser une lecture critique de l’œuvre d’Andrea Zanzotto (1921-2011) à travers la perspective du “registre du réel”, un des points conceptuels fondateurs de la théorie du psychanalyste Jacques Lacan (1901-1981). En prenant comme point de départ les résultats de Stefano Agosti (1930), critique psychanalytique qui a exploré avec profit la poésie de Zanzotto à travers les concepts de la phase structuraliste de la pensée lacanienne, on essaie de continuer cette exploration à travers les concepts de la phase du réel, c’est-à-dire de ce qui est exclu de l’ordre du langage.La recherche se compose de trois parties: une traversée de certains points de l’itinéraire zanzottien (partie I), des analyses textuelles détaillées (partie II) et une étude du rôle du lecteur et de certains éléments du paratexte (partie III). Trois explorations intégrées qui contribuent à comprendre le rapport de la poésie de Zanzotto avec la dimension du non-sens, de l’impossible à dire. / This research aims to realize a critical reading of the work of the Italian poet Andrea Zanzotto through the perspective of the Lacanian Real. What is Lacan’s Real? The real is a domain that is outside language, “that which resists symbolization absolutely” (Lacan).The work is composed of three parts. In the first one, we shall go through the poetical itinerary in order to describe the relationship of the poet with the fundamental object of his poetical universe: the landscape. In the second part, entitled Textual analysis, we shall verify the hypothesis of the first part on four single texts, describing particularly the typical unstructured textuality of Zanzotto’s poetry.In the last part, we shall both pay attention on Zanzotto’s idea of reading and on the idea of the paratext. At this level, the analysis shows us the changes of the structural shapes facing the void and the lack of meaning from another point of view.
128

Desenvolvimento de plano de incentivo de longo prazo para funcionários baseado em opções fantasmas em uma startup

Machado, Rafael Ruivo January 2018 (has links)
As startups vêm provocando uma mudança profunda no mundo dos negócios, e a cada ano mais startups são fundadas no Brasil. O sucesso destas empresas não depende exclusivamente do desenvolvimento de um produto/serviço inovador e um modelo de negócio escalável, mas também da aplicação de ferramentas de incentivo de longo prazo que permitam a formação de times de alto desempenho altamente engajados, e o controle do caixa, que nos primeiros anos é tipicamente escasso dadas as características de risco destes novos negócios. No entanto, o desconhecimento de ferramentas de incentivo de longo prazo por parte dos empreendedores e a limitada discussão na literatura do seu efeito conjunto nas dimensões de pessoas e financeira faz com que muitas startups não implementem tais planos nos seus primeiros anos de existência, o que pode afetar diretamente o sucesso do negócio. Mecanismos inovativos de incentivo, como as opções fantasmas (phantom stock options), são particularmente desconhecidos e pouco aplicados no contexto brasileiro de startups. O objetivo deste trabalho é desenvolver um plano de incentivo de longo prazo baseado em opções fantasmas em uma startup, bem como gerar conhecimento para apoiar futuras pesquisas acadêmicas no campo. Este objetivo foi atingido por meio de uma pesquisa-ação e os resultados confirmaram a importância desta ferramenta para a atração de talentos, engajamento do time, redução de exposição de caixa e redução de assimetria da informação na empresa, já que o profissional passa a entender e mensurar o valor de sua contribuição individual para a equipe e, consequentemente, para o atingimento do seu bônus. / Startups have been bringing about a profound change in the business world, and each year more startups are founded in Brazil. The success of these companies does not depend exclusively on the development of an innovative product / service and a scalable business model, but also on the application of long-term incentive tools that allow the formation of highly engaged high performance teams and cash control, which in the early years is typically scarce given the risk characteristics of these new businesses. However, the lack of knowledge of long-term incentive tools on the part of entrepreneurs and the limited discussion in the literature of their combined effect on the human and financial dimensions means that many startups do not implement such plans in their early years of existence. Can directly affect the success of the business. Innovative incentive mechanisms, such as phantom stock options, are particularly unknown and little applied in the Brazilian context of startups. The purpose of this paper is to illustrate the creation and implementation of a long-term incentive plan based on phantom options in a startup, as well as generate knowledge to support future academic research in the field. This objective was reached through an action research and the results confirmed the importance of this tool for the attraction of talents, team engagement, reduction of cash exposure and reduction of asymmetry of information in the company, since the professional comes to understand and measure the value of your individual contribution to the team and, consequently, to the attainment of your bonus.
129

Anisotropy in Diffusion and Electrical Conductivity Distributions of TX-151 Phantoms

January 2015 (has links)
abstract: Among electrical properties of living tissues, the differentiation of tissues or organs provided by electrical conductivity is superior. The pathological condition of living tissues is inferred from the spatial distribution of conductivity. Magnetic Resonance Electrical Impedance Tomography (MREIT) is a relatively new non-invasive conductivity imaging technique. The majority of conductivity reconstruction algorithms are suitable for isotropic conductivity distributions. However, tissues such as cardiac muscle and white matter in the brain are highly anisotropic. Until recently, the conductivity distributions of anisotropic samples were solved using isotropic conductivity reconstruction algorithms. First and second spatial derivatives of conductivity (∇σ and ∇2σ ) are integrated to obtain the conductivity distribution. Existing algorithms estimate a scalar conductivity instead of a tensor in anisotropic samples. Accurate determination of the spatial distribution of a conductivity tensor in an anisotropic sample necessitates the development of anisotropic conductivity tensor image reconstruction techniques. Therefore, experimental studies investigating the effect of ∇2σ on degree of anisotropy is necessary. The purpose of the thesis is to compare the influence of ∇2σ on the degree of anisotropy under two different orthogonal current injection pairs. The anisotropic property of tissues such as white matter is investigated by constructing stable TX-151 gel layer phantoms with varying degrees of anisotropy. MREIT and Diffusion Magnetic Resonance Imaging (DWI) experiments were conducted to probe the conductivity and diffusion properties of phantoms. MREIT involved current injection synchronized to a spin-echo pulse sequence. Similarities and differences in the divergence of the vector field of ∇σ (∇2σ) among anisotropic samples subjected to two different current injection pairs were studied. DWI of anisotropic phantoms involved the application of diffusion-weighted magnetic field gradients with a spin-echo pulse sequence. Eigenvalues and eigenvectors of diffusion tensors were compared to characterize diffusion properties of anisotropic phantoms. The orientation of current injection electrode pair and degree of anisotropy influence the spatial distribution of ∇2σ. Anisotropy in conductivity is preserved in ∇2σ subjected to non-symmetric electric fields. Non-symmetry in electric field is observed in current injections parallel and perpendicular to the orientation of gel layers. The principal eigenvalue and eigenvector in the phantom with maximum anisotropy display diffusion anisotropy. / Dissertation/Thesis / Masters Thesis Bioengineering 2015
130

Desenvolvimento de plano de incentivo de longo prazo para funcionários baseado em opções fantasmas em uma startup

Machado, Rafael Ruivo January 2018 (has links)
As startups vêm provocando uma mudança profunda no mundo dos negócios, e a cada ano mais startups são fundadas no Brasil. O sucesso destas empresas não depende exclusivamente do desenvolvimento de um produto/serviço inovador e um modelo de negócio escalável, mas também da aplicação de ferramentas de incentivo de longo prazo que permitam a formação de times de alto desempenho altamente engajados, e o controle do caixa, que nos primeiros anos é tipicamente escasso dadas as características de risco destes novos negócios. No entanto, o desconhecimento de ferramentas de incentivo de longo prazo por parte dos empreendedores e a limitada discussão na literatura do seu efeito conjunto nas dimensões de pessoas e financeira faz com que muitas startups não implementem tais planos nos seus primeiros anos de existência, o que pode afetar diretamente o sucesso do negócio. Mecanismos inovativos de incentivo, como as opções fantasmas (phantom stock options), são particularmente desconhecidos e pouco aplicados no contexto brasileiro de startups. O objetivo deste trabalho é desenvolver um plano de incentivo de longo prazo baseado em opções fantasmas em uma startup, bem como gerar conhecimento para apoiar futuras pesquisas acadêmicas no campo. Este objetivo foi atingido por meio de uma pesquisa-ação e os resultados confirmaram a importância desta ferramenta para a atração de talentos, engajamento do time, redução de exposição de caixa e redução de assimetria da informação na empresa, já que o profissional passa a entender e mensurar o valor de sua contribuição individual para a equipe e, consequentemente, para o atingimento do seu bônus. / Startups have been bringing about a profound change in the business world, and each year more startups are founded in Brazil. The success of these companies does not depend exclusively on the development of an innovative product / service and a scalable business model, but also on the application of long-term incentive tools that allow the formation of highly engaged high performance teams and cash control, which in the early years is typically scarce given the risk characteristics of these new businesses. However, the lack of knowledge of long-term incentive tools on the part of entrepreneurs and the limited discussion in the literature of their combined effect on the human and financial dimensions means that many startups do not implement such plans in their early years of existence. Can directly affect the success of the business. Innovative incentive mechanisms, such as phantom stock options, are particularly unknown and little applied in the Brazilian context of startups. The purpose of this paper is to illustrate the creation and implementation of a long-term incentive plan based on phantom options in a startup, as well as generate knowledge to support future academic research in the field. This objective was reached through an action research and the results confirmed the importance of this tool for the attraction of talents, team engagement, reduction of cash exposure and reduction of asymmetry of information in the company, since the professional comes to understand and measure the value of your individual contribution to the team and, consequently, to the attainment of your bonus.

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