855 resultados para Sight
Resumo:
Attractive business cases in various application fields contribute to the sustained long-term interest in indoor localization and tracking by the research community. Location tracking is generally treated as a dynamic state estimation problem, consisting of two steps: (i) location estimation through measurement, and (ii) location prediction. For the estimation step, one of the most efficient and low-cost solutions is Received Signal Strength (RSS)-based ranging. However, various challenges - unrealistic propagation model, non-line of sight (NLOS), and multipath propagation - are yet to be addressed. Particle filters are a popular choice for dealing with the inherent non-linearities in both location measurements and motion dynamics. While such filters have been successfully applied to accurate, time-based ranging measurements, dealing with the more error-prone RSS based ranging is still challenging. In this work, we address the above issues with a novel, weighted likelihood, bootstrap particle filter for tracking via RSS-based ranging. Our filter weights the individual likelihoods from different anchor nodes exponentially, according to the ranging estimation. We also employ an improved propagation model for more accurate RSS-based ranging, which we suggested in recent work. We implemented and tested our algorithm in a passive localization system with IEEE 802.15.4 signals, showing that our proposed solution largely outperforms a traditional bootstrap particle filter.
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BACKGROUND Paediatric supraglottic airway devices AmbuAura-i and Air-Q were designed as conduits for tracheal intubation. Although fibreoptic-guided intubation has proved successful, blind intubation as a rescue technique has never been evaluated. OBJECTIVE Evaluation of blind intubation through AmbuAura-i and Air-Q. On the basis of fibreoptic view data, we hypothesised that the success rate with the AmbuAura-i would be higher than with the Air-Q. DESIGN A prospective, randomised controlled trial with institutional review board (IRB) approval and written informed consent. SETTING University Childrens' Hospital; September 2012 to July 2014. PATIENTS Eighty children, American Society of Anesthesiologists (ASA) class I to III, weight 5 to 50 kg. INTERVENTIONS Tracheal intubation was performed through the randomised device with the tip of a fibrescope placed inside and proximal to the tip of the tracheal tube. This permitted sight of tube advancement, but without fibreoptic guidance (visualised blind intubation). MAIN OUTCOME MEASURES Primary outcome was successfully visualised blind intubation; secondary outcomes included supraglottic airway device success, insertion times, airway leak pressure, fibreoptic view and adverse events. RESULTS Personal data did not differ between groups. In contrast to our hypothesis, blind intubation was possible in 15% with the Air-Q and in 3% with the AmbuAura-i [95% confidence interval (95% CI) 6 to 31 vs. 0 to 13%; P = 0.057]. First attempt supraglottic airway device insertion success rates were 95% (Air-Q) and 100% (AmbuAura-i; 95% CI 83 to 99 vs. 91 to 100; P = 0.49). Median leak pressures were 18 cmH2O (Air-Q) and 17 cmH2O [AmbuAura-i; interquartile range (IQR) 14 to 18 vs. 14 to 19 cmH2O; P = 0.66]. Air-Q insertion was slower (27 vs. 19 s, P < 0.001). There was no difference in fibreoptic view, or adverse events (P > 0.05). In one child (Air-Q size 1.5, tube size 3.5), the tube dislocated during device removal. CONCLUSION Ventilation with both devices is reliable, but success of blind intubation is unacceptably low and cannot be recommended for elective or rescue purposes. If intubation through a paediatric supraglottic airway device is desired, we suggest that fibreoptic guidance is used. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT01692522.
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Many location-based services target users in indoor environments. Similar to the case of dense urban areas where many obstacles exist, indoor localization techniques suffer from outlying measurements caused by severe multipath propaga??tion and non-line-of-sight (NLOS) reception. Obstructions in the signal path caused by static or mobile objects downgrade localization accuracy. We use robust multipath mitigation techniques to detect and filter out outlying measurements in indoor environments. We validate our approach using a power-based lo??calization system with GSM. We conducted experiments without any prior knowledge of the tracked device's radio settings or the indoor radio environment. We obtained localization errors in the range of 3m even if the sensors had NLOS links to the target device.
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PURPOSE To evaluate a low-cost, inertial sensor-based surgical navigation solution for periacetabular osteotomy (PAO) surgery without the line-of-sight impediment. METHODS Two commercial inertial measurement units (IMU, Xsens Technologies, The Netherlands), are attached to a patient's pelvis and to the acetabular fragment, respectively. Registration of the patient with a pre-operatively acquired computer model is done by recording the orientation of the patient's anterior pelvic plane (APP) using one IMU. A custom-designed device is used to record the orientation of the APP in the reference coordinate system of the IMU. After registration, the two sensors are mounted to the patient's pelvis and acetabular fragment, respectively. Once the initial position is recorded, the orientation is measured and displayed on a computer screen. A patient-specific computer model generated from a pre-operatively acquired computed tomography scan is used to visualize the updated orientation of the acetabular fragment. RESULTS Experiments with plastic bones (eight hip joints) performed in an operating room comparing a previously developed optical navigation system with our inertial-based navigation system showed no statistically significant difference on the measurement of acetabular component reorientation. In all eight hip joints the mean absolute difference was below four degrees. CONCLUSION Using two commercially available inertial measurement units we show that it is possible to accurately measure the orientation (inclination and anteversion) of the acetabular fragment during PAO surgery and therefore to successfully eliminate the line-of-sight impediment that optical navigation systems have.
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The so-called Dutch Pranketing Room of Alethea Talbot, Countess of Arundel, at Tart Hall was a site of domestic experiments, courtly splendour and global ambition. Lady Arundel, the probable author of a famous recipe book, would have used Tart Hall for cooking and experiments as well as for impressive dinner parties, and she would have used large amounts of sugar to create intricate imitations of meat and vegetables to astonish, entertain and delight her guests. Linking household practice with global trade as well as artistic creation, Lady Arundel’s banquets are situated not only between a national tradition of cooking, as it appears in Markham’s manuals, and the new possibilities the arising global trade provided, but also played with a mismatch between taste and sight. This mediating role could be compared to that played by the artists the Countess employed. Within this context it is worth noting that a series of paintings displayed in the building’s gallery showed still lifes, markets, and a cook. The inventory of Tart Hall gives an insight into the world of the widely travelled collector and patron of Van Dyck and Rubens, but raises also a number of questions. In my talk I would like to explore the Countess’ Pranketing Room as a site of mediation between alimentary and painterly experiments, considering the use of recipes, experience, invention and transformation
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Widely publicized reports of fresh MBAs getting multiple job offers with six-figure annual salaries leave a long-lasting general impression about the high quality of selected business schools. While such spectacular achievement in job placement rightly deserves recognition, one should not lose sight of the resources expended in order to accomplish this result. In this study, we employ a measure of Pareto-Koopmans global efficiency to evaluate the efficiency levels of the MBA programs in Business Week's top-rated list. We compute input- and output-oriented radial and non-radial efficiency measures for comparison. Among three tier groups, the schools from a higher tier group on average are more efficient than those from lower tiers, although variations in efficiency levels do occur within the same tier, which exist over different measures of efficiency.
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Uterine leiomyosarcoma (ULMS) is an aggressive malignancy characterized by marked chemoresistance, frequent relapses, and poor outcome. Despite efforts to improve survival over the past several decades, only minimal advances have been made. Hence, there is an urgent and unmet need for better understanding of the molecular deregulations that underlay ULMS and development of more effective therapeutic strategies. This work identified several common deregulations in a large (n=208) tissue microarray of ULMS compared to GI smooth muscle, myometrium, and leiomyoma controls. Our results suggest that significant loss of smooth muscle and gynecological differentiation markers is common in ULMS, a finding that could help render improved ULMS diagnosis, especially for advanced disease. Similarly to reports in other malignancies, we found that several cancer-related proteins were differentially expressed; these could be useful together as biomarkers for ULMS. Notably, we identified significant upregulation and overexpression of the mTOR pathway in ULMS, examined the possible contribution of tyrosine kinase receptor deregulation promoting mTOR activation, and unraveled a role for pS6RP and p4EBP1 as molecular disease prognosticators. The significance of mTOR activation in ULMS and its potential as a therapeutic target were further investigated. Rapamycin abrogated ULMS cell growth and cell cycle progression in vitro but induced only sight growth delay in vivo. Given that effective mTOR therapies likely require combination mTOR blockade with inhibition of other targets, coupled with recent observations suggesting that Aurora A kinase (Aurk A) deregulations commonly occur in ULMS, the preclinical impact of dually targeting both pathways was evaluated. Combined therapy with rapamycin (an mTORC1 inhibitor) and MLN8237 (an investigational Aurk A inhibitor) profoundly and synergistically abrogated ULMS growth in vitro. Interestingly, the superior effects were noted only when MLN8237 was pre-administered. This novel therapeutic combination and scheduling regimen resulted in marked tumor growth inhibition in vivo. Together, these data support further exploration of dual mTOR and Aurk A blockade for the treatment of human ULMS.
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A portable Fourier transform spectrometer (FTS), model EM27/SUN, was deployed onboard the research vessel Polarstern to measure the column-average dry air mole fractions of carbon dioxide (XCO2) and methane (XCH4) by means of direct sunlight absorption spectrometry. We report on technical developments as well as data calibration and reduction measures required to achieve the targeted accuracy of fractions of a percent in retrieved XCO2 and XCH4 while operating the instrument under field conditions onboard the moving platform during a 6-week cruise on the Atlantic from Cape Town (South Africa, 34° S, 18° E; 5 March 2014) to Bremerhaven (Germany, 54° N, 19° E; 14 April 2014). We demonstrate that our solar tracker typically achieved a tracking precision of better than 0.05° toward the center of the sun throughout the ship cruise which facilitates accurate XCO2 and XCH4 retrievals even under harsh ambient wind conditions. We define several quality filters that screen spectra, e.g., when the field of view was partially obstructed by ship structures or when the lines-of-sight crossed the ship exhaust plume. The measurements in clean oceanic air, can be used to characterize a spurious air-mass dependency. After the campaign, deployment of the spectrometer alongside the TCCON (Total Carbon Column Observing Network) instrument at Karlsruhe, Germany, allowed for determining a calibration factor that makes the entire campaign record traceable to World Meteorological Organization (WMO) standards. Comparisons to observations of the GOSAT satellite and concentration fields modeled by the European Centre for Medium-Range Weather Forecasts (ECMWF) Copernicus Atmosphere Monitoring Service (CAMS) demonstrate that the observational setup is well suited to provide validation opportunities above the ocean and along interhemispheric transects.
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Favorecida por el proyecto económico y político de la globalización, es posible observar cómo, desde las últimas décadas del pasado siglo, se ha ido agudizando una tendencia a la hibridación que, si bien podríamos considerar casi innata de la condición humana, ha trascendido en nuestros días la mera enunciación retórica hasta llegar a impregnar casi todos los estratos de la cultura. En el campo de los estudios literarios este proceso de mixturación ha contribuido a generar una verdadera explosión de la llamada literatura de frontera, caracterizada no sólo por una mutación en las mentalidades de los sectores sociales y étnicos -desde los que se origina-, sino por profundos cambios en las mismas estructuras sociales, culturales y lingüísticas. Esta problemática pone en cuestión la homogeneidad y la esencialidad de la identidad cultural, pues es un fenómeno actual que nos remite, inevitablemente, a la complejidad de la identidad. Precisamente, podríamos hablar de deslizamientos que se van produciendo en los diferentes planos de las manifestaciones artísticas, tendiendo éstos a amalgamarse, a fundirse uno con otros, en un cruzamiento de líneas de fuga, de rupturas, que atraviesan ese nuevo espacio, el Tercer Espacio, donde los diferentes discursos se van hibridando unos con otros, rompiendo la imagen de unidad, la imagen unitaria y tradicional. Unidad que no existió nunca y que no puede existir de ningún modo, porque es una imagen acotada que se esfuma en el caótico tejido de lo vivo, en la conformación y evolución de la raza humana.
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A partir de la escala de los entes, Romero plantea el proceso que se desarrolla desde la inmanencia hacia la trascendencia, hasta llegar a su máxima expresión en el espíritu. En el hombre, se manifiesta en el paso del individuo a la persona, la cual trasciende hacia la realización del valor, a través del “deber ser". En la actualidad, Lipovetsky presenta otra manera de concebir al hombre, la cual se expresa en un individualismo creciente, que está determinado por sus intereses particulares, sin proyección alguna hacia los otros y sin reconocer otro valor que no sea la realización de “su sí mismo". Frente a ello, urge promover el desarrollo de un “individualismo responsable", que recupere los valores éticos del hombre y su relación con los otros, sin perder de vista su propia realización. Este concepto, en otras palabras, reactualiza los planteos personalistas de Romero, en esta sociedad posmoderna.
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La conocida tesis de Tomás de Aquino de que el ver «es el más elevado de todos [los sentidos]» (De anima, c13) está detrás de la metáfora de la vista como expresión del conocer y de la afirmación de que este sentido es el más inmaterial (y más próximo a lo espiritual) de todos los sentidos externos. Esta noción de ‘ver’ (y de ‘sentir’) presentaba dos elementos constitutivos de todo sentido: lo que tenía como inmutación o impresión (contacto con la realidad) y su carácter formal (aprehensor de la forma sensible). Lograr una posición unitaria que integre tanto el elemento impresivo (dador de realidad) como aprehensivo o cognoscitivo ha sido también el intento de posturas filosóficas contemporáneas (como la de Zubiri) respondiendo a posiciones insuficientes que o bien han primado el elemento de inmediatez, o han señalado el sentir como mero dador de contenido a la inteligencia. Así, este autor revisa las formas de interpretar el sentido, señalando la primariedad del sentido del tacto y la fundamentalidad de éste para la comprensión del verdadero estatuto del sentir humano, poniendo de nuevo en actualidad la reflexión del Aquinate sobre el sentir, indicando a su vez la diferencia de planteamientos de ambos autores.
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Hablar de Epistemología en el ámbito de nuestra Facultad nos traslada a la discusión de algo que, en general, y a simple vista, aparece como alejado de la cotidiana actividad en nuestro espacio de trabajo. Desde la cátedra de “Epistemología y Metodología de la Investigación Científica" queremos efectuar algunas aclaraciones. Nuestro propósito es llevar algo de luz sobre esta disciplina, en especial para contribuir a esclarecer conceptos que se utilizan desde la filosofía y las ciencias sociales en general, y que recuperados por científicos ligados a las ciencias naturales posteriormente en su etapa fragmentada, tornaron su significación a posiciones inamovibles donde se pretendió establecer una misma mirada para todo el quehacer científico, hecho equívoco que, como veremos, la ciencia actual ya no discute. Debido a lo extenso del tema, hemos preferido realizar una primera parte en esta oportunidad a modo de introducción, y así irnos introduciendo en el apasionante mundo de la ciencia.
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El objetivo de este trabajo es analizar la reacción de las distintas teorías democráticas frente a las teorías de la élite y la forma en que, a partir de una mutua penetración, incorporaron algunos de sus principios dando lugar a lo que se ha denominado como "elitismo democrático". Se trata de recuperar para la democracia la máxima expresión posible de aquellos valores atribuidos por el modelo clásico. Y el énfasis está puesto en el término "posible", pues lo que se intenta es pensar empíricamente la democracia, pero sin perder de vista su dimensión normativa. Entonces, ¿qué es lo que hace preferible al sistema democrático (y es esto a lo que debe responder la filosofía política)?, ¿qué es lo que hace deseable a la democracia?, ¿es el hecho de que sea la mayoría la que gobierne, (hecho que no ocurre empíricamente hablando)?, ¿es la posibilidad de dar un lugar a cualquier grupo que desee hacer tanto una demanda como una oferta política?, ¿es la libre competencia por el poder?
Resumo:
El trabajo toma como objeto el semanario argentino La Nota para leer, entre 1915 y 1917, a la luz del Gran Guerra, algunas emergencias de la reconfiguración de determinados tópicos de los debates intelectuales y literarios dominantes en los años inmediatamente previos y aún vigentes, como lo fue la problemática de lo nacional y asociado a ella, el lugar asignado a las relaciones culturales entre España y Argentina en ese terreno. De tal modo, a través de intervenciones de autores diversos en torno del conflicto bélico, la revista a la vez que muestra cómo se piensan la función de la cultura -y por tanto de los intelectuales- ofrece, según los casos, una visión más o menos crítica de aquellas relaciones. Así, por ejemplo, sucede con 'El centenario de Cervantes' (Rodó) o las 'Meditaciones sobre el nacionalismo' (Rojas), 'América y España' (Blanco Fombona), 'El manifiesto germanista de los intelectuales españoles' (Unamuno), o 'El cuento de la raza' (Del Campo)
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El trabajo se detiene en el pasaje del Poema de Mio Cid en el cual se hace referencia a Longinos (vv. 351-357), centurión que habría custodiado a Cristo durante la crucifixión y quien milagrosamente habría recobrado la vista a raíz de que sus ojos ciegos fueran alcanzados por la sangre de Su costado. El análisis se centra en el procedimiento a través del cual este personaje es insertado para relacionarlo con el Cid y sus hombres, estableciéndose una cadena de significaciones cuya finalidad ideológica es la de enmarcar la gesta del Cid dentro de un juego de identidades con la gran historia del pueblo de Dios.