934 resultados para Angle of Arrival (AoA)


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Bei der Simulation von Logistik- und Produktionssystem werden Zufallszahlengeneratoren verwendet, um stochastische Einflüsse zu modellieren. Ein wichtiges Qualitätsmerkmal dieser Generatoren ist die Er-zeugung möglichst unabhängiger Zufallszahlen. Werden jedoch reale Prozesse betrachtet, so sind die Daten im Allgemeinen nicht unabhängig. Diese Arbeit befasst sich mit der Analyse von Praxisdaten bezüglich des Auftretens von Abhängigkeiten. Dazu werden Korrelationsstrukturen gesucht. Außerdem wird gezeigt, dass unabhängige Zufallszahlen in der Regel ungeeignet sind, um stochastische Prozesse mit ausgeprägten Abhängigkeiten zu modellieren.

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The synthesis of a novel bicyclic thymidine analogue carrying a β-fluoro substituent at C6' (6'F-bcT) has been achieved. Key steps of the synthesis were an electrophilic fluorination/stereospecific hydrogenation sequence of a bicyclo sugar intermediate, followed by an N-iodo-succinimide-induced stereoselective nucleosidation. A corresponding phosphoramidite building block was then prepared and used for oligonucleotide synthesis. Tm measurements of oligonucleotides with single and double incorporations showed a remarkable stabilization of duplex formation particularly with RNA as complement without compromising pairing selectivity. Increases in Tm were in the range of +1-2 °C compared to thymidine and +1-3 °C compared to a standard bc-T residue. Structural investigations of the 6'F-bcT nucleoside by X-ray crystallography showed an in-line arrangement of the fluorine substituent with H6 of thymine, however, with a distance that is relatively long for a nonclassical CF-HC hydrogen bond. In contrast, structural investigations in solution by (1)H and (13)C NMR clearly showed scalar coupling of fluorine with H6 and C6 of the nucleobase, indicating the existence of at least weak electrostatic interactions. On the basis of these results, we put forward the hypothesis that these weak CF-HC6 electrostatic interactions increase duplex stability by orienting and partially freezing torsion angle χ of the 6'F-bcT nucleoside.

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The Imager for Low Energetic Neutral Atoms test facility at the University of Bern was developed to investigate, characterize, and quantify physical processes on surfaces that are used to ionize neutral atoms before their analysis in neutral particle-sensing instruments designed for space research. The facility has contributed valuable knowledge of the interaction of ions with surfaces (e.g., fraction of ions scattered from surfaces and angular scattering distribution) and employs a novel measurement principle for the determination of secondary electron emission yields as a function of energy, angle of incidence, particle species, and sample surface for low particle energies. Only because of this test facility it was possible to successfully apply surface-science processes for the new detection technique for low-energetic neutral particles with energies below about 1 keV used in space applications. All successfully flown spectrometers for the detection of low-energetic neutrals based on the particle–surface interaction process use surfaces evaluated, tested, and calibrated in this facility. Many instruments placed on different spacecraft (e.g., Imager for Magnetopause-to-Aurora Global Exploration, Chandrayaan-1, Interstellar Boundary Explorer, etc.) have successfully used this technique.

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Time series of geocenter coordinates were determined with data of two global navigation satellite systems (GNSSs), namely the U.S. GPS (Global Positioning System) and the Russian GLONASS (Global’naya Nawigatsionnaya Sputnikowaya Sistema). The data was recorded in the years 2008–2011 by a global network of 92 permanently observing GPS/GLONASS receivers. Two types of daily solutions were generated independently for each GNSS, one including the estimation of geocenter coordinates and one without these parameters. A fair agreement for GPS and GLONASS was found in the geocenter x- and y-coordinate series. Our tests, however, clearly reveal artifacts in the z-component determined with the GLONASS data. Large periodic excursions in the GLONASS geocenter z-coordinates of about 40 cm peak-to-peak are related to the maximum elevation angles of the Sun above/below the orbital planes of the satellite system and thus have a period of about 4 months (third of a year). A detailed analysis revealed that the artifacts are almost uniquely governed by the differences of the estimates of direct solar radiation pressure (SRP) in the two solution series (with and without geocenter estimation). A simple formula is derived, describing the relation between the geocenter z-coordinate and the corresponding parameter of the SRP. The effect can be explained by first-order perturbation theory of celestial mechanics. The theory also predicts a heavy impact on the GNSS-derived geocenter if once-per-revolution SRP parameters are estimated in the direction of the satellite’s solar panel axis. Specific experiments using GPS observations revealed that this is indeed the case. Although the main focus of this article is on GNSS, the theory developed is applicable to all satellite observing techniques. We applied the theory to satellite laser ranging (SLR) solutions using LAGEOS. It turns out that the correlation between geocenter and SRP parameters is not a critical issue for the SLR solutions. The reasons are threefold: The direct SRP is about a factor of 30–40 smaller for typical geodetic SLR satellites than for GNSS satellites, allowing it in most cases to not solve for SRP parameters (ruling out the correlation between these parameters and the geocenter coordinates); the orbital arc length of 7 days (which is typically used in SLR analysis) contains more than 50 revolutions of the LAGEOS satellites as compared to about two revolutions of GNSS satellites for the daily arcs used in GNSS analysis; the orbit geometry is not as critical for LAGEOS as for GNSS satellites, because the elevation angle of the Sun w.r.t. the orbital plane is usually significantly changing over 7 days.

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This article analyses narrations of German memories in relation to the incorporation of Islam into Germany. Memory narratives are not approached from the angle of identity, but as part of the continuous business of rationalizing politics inside and beyond the state. The citational use of narratives authorizes interventions in the process of government by constituting its objects, determining the means and aims of government and defining its authority. Narratives are a governmental practice, i.e. they connect politics narrowly defined with individual conduct, since narratives allow determination of a social context and what constitutes adequate behaviour within it. In this way, they help to orient practices of freedom. Acts such as the cultivating of an ethics of interreligious competition, involvement in specific forms of dialogue, or activism against Islamophobia and anti-Semitism derive meaning in part through such narratives, while simultaneously contributing new meaning.

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The WTO Agreement on Agriculture (AoA) is the predominant multilateral legal framework governing agricultural trade. The objective of the AoA is to liberalise trade in agriculture through reductions in tariffs, domestic support and export subsidies. The AoA has not, however, ‘levelled the playing field’ and has not resulted in the equitable distribution of food, particularly for the poorer developing countries. On the other hand, support for small farmers does not ensure food security for the poor. While food security has no simple solutions such as “free trade is good for you”, reform proposals for trade rules which only address agricultural policy instruments fail to account for consumer and other interests: neither tariff reductions and subsidy disciplines, nor safeguards and other measures of producer protection can automatically increase food security. Rather, what is needed is the full and proper implementation of a number of commitments which the international community has already entered into in various human rights treaties, but which even the envisaged results of the now failed Doha Round negotiations could not ensure without revisiting relevant multilateral trade and investment rules.

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Time-based indoor localization has been investigated for several years but the accuracy of existing solutions is limited by several factors, e.g., imperfect synchronization, signal bandwidth and indoor environment. In this paper, we compare two time-based localization algorithms for narrow-band signals, i.e., multilateration and fingerprinting. First, we develop a new Linear Least Square (LLS) algorithm for Differential Time Difference Of Arrival (DTDOA). Second, fingerprinting is among the most successful approaches used for indoor localization and typically relies on the collection of measurements on signal strength over the area of interest. We propose an alternative by constructing fingerprints of fine-grained time information of the radio signal. We offer comprehensive analytical discussions on the feasibility of the approaches, which are backed up by evaluations in a software defined radio based IEEE 802.15.4 testbed. Our work contributes to research on localization with narrow-band signals. The results show that our proposed DTDOA-based LLS algorithm obviously improves the localization accuracy compared to traditional TDOA-based LLS algorithm but the accuracy is still limited because of the complex indoor environment. Furthermore, we show that time-based fingerprinting is a promising alternative to power-based fingerprinting.

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BACKGROUND The iliocapsularis muscle is an anterior hip structure that appears to function as a stabilizer in normal hips. Previous studies have shown that the iliocapsularis is hypertrophied in developmental dysplasia of the hip (DDH). An easy MR-based measurement of the ratio of the size of the iliocapsularis to that of adjacent anatomical structures such as the rectus femoris muscle might be helpful in everyday clinical use. QUESTIONS/PURPOSES We asked (1) whether the iliocapsularis-to-rectus-femoris ratio for cross-sectional area, thickness, width, and circumference is increased in DDH when compared with hips with acetabular overcoverage or normal hips; and (2) what is the diagnostic performance of these ratios to distinguish dysplastic from pincer hips? METHODS We retrospectively compared the anatomy of the iliocapsularis muscle between two study groups with symptomatic hips with different acetabular coverage and a control group with asymptomatic hips. The study groups were selected from a series of patients seen at the outpatient clinic for DDH or femoroacetabular impingement. The allocation to a study group was based on conventional radiographs: the dysplasia group was defined by a lateral center-edge (LCE) angle of < 25° with a minimal acetabular index of 14° and consisted of 45 patients (45 hips); the pincer group was defined by an LCE angle exceeding 39° and consisted of 37 patients (40 hips). The control group consisted of 30 asymptomatic hips (26 patients) with MRIs performed for nonorthopaedic reasons. The anatomy of the iliocapsularis and rectus femoris muscle was evaluated using MR arthrography of the hip and the following parameters: cross-sectional area, thickness, width, and circumference. The iliocapsularis-to-rectus-femoris ratio of these four anatomical parameters was then compared between the two study groups and the control group. The diagnostic performance of these ratios to distinguish dysplasia from protrusio was evaluated by calculating receiver operating characteristic (ROC) curves and the positive predictive value (PPV) for a ratio > 1. Presence and absence of DDH (ground truth) were determined on plain radiographs using the previously mentioned radiographic parameters. Evaluation of radiographs and MRIs was performed in a blinded fashion. The PPV was chosen because it indicates how likely a hip is dysplastic if the iliocapsularis-to-rectus-femoris ratio was > 1. RESULTS The iliocapsularis-to-rectus-femoris ratio for cross-sectional area, thickness, width, and circumference was increased in hips with radiographic evidence of DDH (ratios ranging from 1.31 to 1.35) compared with pincer (ratios ranging from 0.71 to 0.90; p < 0.001) and compared with the control group, the ratio of cross-sectional area, thickness, width, and circumference was increased (ratios ranging from 1.10 to 1.15; p ranging from 0.002 to 0.039). The area under the ROC curve ranged from 0.781 to 0.852. For a one-to-one iliocapsularis-to-rectus-femoris ratio, the PPV was 89% (95% confidence interval [CI], 73%-96%) for cross-sectional area, 77% (95% CI, 61%-88%) for thickness, 83% (95% CI, 67%-92%) for width, and 82% (95% CI, 67%-91%) for circumference. CONCLUSIONS The iliocapsularis-to-rectus-femoris ratio seems to be a valuable secondary sign of DDH. This parameter can be used as an adjunct for clinical decision-making in hips with borderline hip dysplasia and a concomitant cam-type deformity to identify the predominant pathology. Future studies will need to prove this finding can help clinicians determine whether the borderline dysplasia accounts for the hip symptoms with which the patient presents. LEVEL OF EVIDENCE Level III, prognostic study.

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In this study four data quality flags are presented for automated and unmanned above-water hyperspectral optical measurements collected underway in the North Sea, The Minch, Irish Sea and Celtic Sea in April/May 2009. Coincident to these optical measurements a DualDome D12 (Mobotix, Germany) camera system was used to capture sea surface and sky images. The first three flags are based on meteorological conditions, to select erroneous incoming solar irradiance (ES) taken during dusk, dawn, before significant incoming solar radiation could be detected or under rainfall. Furthermore, the relative azimuthal angle of the optical sensors to the sun is used to identify possible sunglint free sea surface zones. A total of 629 spectra remained after applying the meteorological masks (first three flags). Based on this dataset, a fourth flag for sunglint was generated by analysing and evaluating water leaving radiance (LW) and remote sensing reflectance (RRS) spectral behaviour in the presence and absence of sunglint salient in the simultaneously available sea surface images. Spectra conditions satisfying "mean LW (700-950 nm) < 2 mW/m**2/nm/Sr" or alternatively "minimum RRS (700-950 nm) < 0.010/Sr", mask the most measurements affected by sunglint, providing efficient flagging of sunglint in automated quality control. It is confirmed that valid optical measurements can be performed 0° <= theta <= 360° although 90° <= theta <= 135° is recommended.

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La presente tesis pretende mostrar cómo lo místico se vertebra en la filosofía siendo lo antropológico lo que opera dicha vertebración tomando como referente la tensión hacia lo absoluto que hay en cada ser humano. La propuesta se diseña en dos grandes bloques: el primero despeja la raigambre del elemento místico en contrapunto con la historia de la racionalidad, repartido en cuatro capítulos que analizan la fenomenología del hecho místico desde la noticia histórico-discursiva y su necesaria hermenéutica, desarrollo que conduce a dos instancias cruciales: el aparente dilema racionalidad-misticismo y la consecuente validación epistemológica del análisis relacional situado en el umbral mística-filosofía. El segundo bloque consta de cinco capítulos que parten de una breve relevamiento del manantial místico que operó de fuente en que abrevaron los cuatro filósofos seleccionados – Unamuno, Bergson, Stein y Mounier – para poder así desarrollar adecuadamente sus propuestas insistiendo en el ángulo cognitivo que nos aboca. Ambos bloques convergen finalmente en las consideraciones últimas que recogen en cuatro ejes temáticos las instancias decisivas a que nos ha conducido el proceso integral de nuestra indagatoria, proceso donde se hace patente la intrínseca co-referencialidad entre el fenómeno ‘mística’ y el fenómeno ‘hombre’ vertidos en la discursividad filosófica.

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Este artículo pretende establecer una diferenciación entre corriente y tradición pedagógica para sugerir una posible relación con la Educación Especial en tanto campo de problemas multidisciplinar , sin descartar las relaciones en su ángulo de modalidad educativa, de conjuntos de servicios y apoyos o de conocimiento profesional para la atención educativa de los sujetos con discapacidad. La intención de fondo consiste en plantear algunas “bases" para reflexionar e investigar sistemáticamente sobre las corrientes pedagógicas de la Educación Especial en las distintas tradiciones pedagógicas, lo cual aportará a la objetivación del campo al tiempo que otorga las condiciones de posibilidad para sumergirse en el acontecer de una historicidad pedagógica en permanente movimiento (aunque no se restrinja, a mediano plazo, únicamente a la pedagogía) y en interconexión fluida con otras culturas y sociedades. De esta manera, el texto puede entenderse como una reflexión de pedagogía general o como una aproximación pedagógica comparada sobre la Educación Especial en América Latina.

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Razão de uma escolha: a importância do periódico O Portuguez e do seu redactor João Bernardo da Rocha Loureiro no desencadear da Revolução Liberal portuguesa de 1820, que deu início ao processo que colocou fim à monarquia absoluta e desencadeou a desconstrução do Antigo Regime em Portugal. Nesta panorâmica, e tendo como horizonte de chegada a fruição da liberdade, pode dizer-se que, enquanto sistema de significações colectivas, o imaginário do redactor Rocha Loureiro parece actuar como reacção ao poder dissolvedor da inteligência, como regulador que satisfaz a busca apaixonada de um grupo ou sociedade que persegue a sua identidade da qual a liberdade é elemento constituinte, fundamental e fundamentador. A liberdade define-se pela ausência de limitação às garantias necessárias para o harmonioso desenvolvimento do indivíduo. Antes de mais a liberdade é, na sua essência, uma ausência de limitação, sendo simultaneamente uma determinação positiva e espontânea da vontade de liberdade em que cada um procura atingir o fim racional de que está possuído. O indivíduo deseja a liberdade com vista a alcançar o melhor possível do seu ser. Na essência, a vontade de liberdade de cada um confunde-se com a vontade colectiva que encontra a sua expressão no poder político.

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Este trabajo consta, fundamentalmente, de dos partes bien diferenciadas. En la primera, se ubica al poeta Osvaldo Horacio Dondo (1902-1962) en el marco de las letras argentinas, cosa que se juzga necesaria, ya que hasta la década del 60 estuvo en la alta estima de muchos, pero luego cayó en el olvido generalizado. Su lugar es peculiar y representativo de aquellos que, habiéndose iniciado en el martinfierrismo, luego siguieron diversos derroteros; en este caso, el de la llamada vanguardia católica. Dondo es en sí mismo digno de ser considerado, como atestigua la autoridad de un Ara y la de un Aguirre, dos de los principales antólogos de la poesía argentina. El rescate de este autor será hecho, por un lado, teniendo en cuenta las antologías en tanto contracara ineludible de la historia de la literatura, de acuerdo con el ya canónico artículo de Alfonso Reyes (1952). Por otro lado, en la segunda parte, se ensaya un abordaje de su escritura desde el ángulo de la lectura como fenómeno complejo, que en cierta medida constituye un rasgo esencial del homo faber, además de actuar a modo de clave de interpretación de sus textos, especialmente los tardíos.