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Avaliação do uso de observáveis coletadas com receptores de navegação pessoal para determinação de coordenadas em linhas base curtas; Evaluation of the use of observable collected with receivers, personal navigation coordinates to determine base lines short

Bielenki Júnior, Cláudio
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/12/2008 Português
Relevância na Pesquisa
25.62%
Nas últimas décadas o uso de equipamentos para posicionamento, principalmente os receptores de navegação pessoal, ganhou relativa importância, e a aquisição desses receptores aumentou consideravelmente. Estes receptores, entretanto, não foram desenvolvidos para trabalhos que exijam acurácia, pois estimam e armazenam as posições com precisão e acurácia da ordem de 03-15 m, com 95% de probabilidade, não armazenam os dados de código e fase e não possuem antenas com centro de fase determinado. Com a disponibilização do protocolo de transmissão dos dados destes receptores, foram desenvolvidos alguns programas para, estando conectados ao receptor por meio de hardware e software, extrair e registrar as observações de navegação (código CA e fase da portadora). Desta forma, o uso de receptores de navegação pessoal para medições de coordenadas com boa acurácia, em linhas base curtas, pode tornar-se uma grande alternativa para área de mensuração com aplicações na Engenharia de Transportes. O alto custo de outras técnicas frente à proposta deste trabalho à uma das grandes dificuldades encontradas para uma maior acurácia nos trabalhos geodésicos aplicados aos transportes. Neste trabalho procurou-se analisar o processamento de dados da fase portadora L1 e código CA...

Atividades do enfermeiro de centro de material e esterilização em instituições hospitalares; Nursing tasks in the materials and sterilization center of hospital institutions.

Gil, Rosineide Feres
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 29/08/2012 Português
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25.63%
A Central de Material e Esterilização é uma unidade que concentra grande parte do arsenal de material médico-hospitalar das instituições de saúde. Tem a responsabilidade de oferecer todos os itens destinados ao cuidado do paciente, com qualidade e segurança, seja para procedimentos diagnósticos, clínicos e cirúrgicos. Para tal, entretanto são necessários investimentos em tecnologia específica e sofisticação no processamento dos materiais de acordo com sua conformidade, demandando dos profissionais que ali atuam o desenvolvimento de competências e habilidades para um desempenho profissional condizente com as necessidades institucionais. Esta pesquisa teve por objetivo identificar o perfil e analisar as atividades realizadas pelos enfermeiros de CME de instituições hospitalares brasileiras, bem como a freqüência de realização das mesmas em diferentes realidades institucionais. Trata-se de um estudo descritivo, de abordagem quantitativa, de corte transversal, que teve como sujeitos da pesquisa, enfermeiros assistenciais ou docentes de unidades de CME de instituições hospitalares públicas, privadas ou filantrópicas. Para seleção dos enfermeiros foi utilizada a técnica de bola de neve. Para coleta de dados foram criados formulários eletrônicos com recurso da planilha Google Docs e enviados eletronicamente aos participantes. Os resultados obtidos evidenciaram em relação ao perfil dos respondentes...

Transcription Elongation by RNA Polymerase I Is Linked to Efficient rRNA Processing and Ribosome Assembly

Schneider, David A.; Michel, Antje; Sikes, Martha L.; Vu, Loan; Dodd, Jonathan A.; Salgia, Shilpa; Osheim, Yvonne N.; Beyer, Ann L.; Nomura, Masayasu
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 27/04/2007 Português
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The synthesis of ribosomes in eukaryotic cells is a complex process involving many nonribosomal protein factors and snoRNAs. In general, the processes of rRNA transcription and ribosome assembly are treated as temporally or spatially distinct. Here, we describe the identification of a point mutation in the second largest subunit of RNA polymerase I near the active center of the enzyme that results in an elongation-defective enzyme in the yeast Saccharomyces cerevisiae. In vivo, this mutant shows significant defects in rRNA processing and ribosome assembly. Taken together, these data suggest that transcription of rRNA by RNA polymerase I is linked to rRNA processing and maturation. Thus, RNA polymerase I, elongation factors, and rRNA sequence elements appear to function together to optimize transcription elongation, coordinating cotranscriptional interactions of many factors/snoRNAs with pre-rRNA for correct rRNA processing and ribosome assembly.

Characterization of Patients who Suffer Asthma Exacerbations using Data Extracted from Electronic Medical Records

Himes, Blanca E.; Kohane, Isaac S.; Ramoni, Marco F.; Weiss, Scott T.
Fonte: American Medical Informatics Association Publicador: American Medical Informatics Association
Tipo: Artigo de Revista Científica
Publicado em //2008; 2008 Português
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The increasing availability of electronic medical records offers opportunities to better characterize patient populations and create predictive tools to individualize health care. We determined which asthma patients suffer exacerbations using data extracted from electronic medical records of the Partners Healthcare System using Natural Language Processing tools from the “Informatics for Integrating Biology to the Bedside” center (i2b2). Univariable and multivariable analysis of data for 11,356 patients (1,394 cases, 9,962 controls) found that race, BMI, smoking history, and age at initial observation are predictors of asthma exacerbations. The area under the receiver operating characteristic curve (AUROC) corresponding to prediction of exacerbations in an independent group of 1,436 asthma patients (106 cases, 1,330 controls) is 0.67. Our findings are consistent with previous characterizations of asthma patients in epidemiological studies, and demonstrate that data extracted by natural language processing from electronic medical records is suitable for the characterization of patient populations.

Discerning Tumor Status from Unstructured MRI Reports—Completeness of Information in Existing Reports and Utility of Automated Natural Language Processing

Cheng, Lionel T. E.; Zheng, Jiaping; Savova, Guergana K.; Erickson, Bradley J.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
Português
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Information in electronic medical records is often in an unstructured free-text format. This format presents challenges for expedient data retrieval and may fail to convey important findings. Natural language processing (NLP) is an emerging technique for rapid and efficient clinical data retrieval. While proven in disease detection, the utility of NLP in discerning disease progression from free-text reports is untested. We aimed to (1) assess whether unstructured radiology reports contained sufficient information for tumor status classification; (2) develop an NLP-based data extraction tool to determine tumor status from unstructured reports; and (3) compare NLP and human tumor status classification outcomes. Consecutive follow-up brain tumor magnetic resonance imaging reports (2000–­2007) from a tertiary center were manually annotated using consensus guidelines on tumor status. Reports were randomized to NLP training (70%) or testing (30%) groups. The NLP tool utilized a support vector machines model with statistical and rule-based outcomes. Most reports had sufficient information for tumor status classification, although 0.8% did not describe status despite reference to prior examinations. Tumor size was unreported in 68.7% of documents...

Free Factories: Unified Infrastructure for Data Intensive Web Services

Zaranek, Alexander Wait; Clegg, Tom; Vandewege, Ward; Church, George M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/05/2008 Português
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We introduce the Free Factory, a platform for deploying data-intensive web services using small clusters of commodity hardware and free software. Independently administered virtual machines called Freegols give application developers the flexibility of a general purpose web server, along with access to distributed batch processing, cache and storage services. Each cluster exploits idle RAM and disk space for cache, and reserves disks in each node for high bandwidth storage. The batch processing service uses a variation of the MapReduce model. Virtualization allows every CPU in the cluster to participate in batch jobs. Each 48-node cluster can achieve 4-8 gigabytes per second of disk I/O. Our intent is to use multiple clusters to process hundreds of simultaneous requests on multi-hundred terabyte data sets. Currently, our applications achieve 1 gigabyte per second of I/O with 123 disks by scheduling batch jobs on two clusters, one of which is located in a remote data center.

Reduced exposure using asymmetric cone beam processing for wide area detector cardiac CT

Bedayat, Arash; Rybicki, Frank J.; Kumamaru, Kanako; Powers, Sara L.; Signorelli, Jason; Steigner, Michael L.; Steveson, Chloe; Soga, Shigeyoshi; Adams, Kimberly; Mitsouras, Dimitrios; Clouse, Melvin; Mather, Richard T.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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The purpose of this study was to estimate dose reduction after implementation of asymmetrical cone beam processing using exposure differences measured in a water phantom and a small cohort of clinical coronary CTA patients. Two separate 320 × 0.5 mm detector row scans of a water phantom used identical cardiac acquisition parameters before and after software modifications from symmetric to asymmetric cone beam acquisition and processing. Exposure was measured at the phantom surface with Optically Stimulated Luminescence (OSL) dosimeters at 12 equally spaced angular locations. Mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at the center plus four peripheral locations in the water phantom. To assess image quality, mean HU and standard deviation (SD) for both approaches were compared using ROI measurements obtained at five points within the water phantom. Retrospective evaluation of 64 patients (37 symmetric; 27 asymmetric acquisition) included clinical data, scanning parameters, quantitative plus qualitative image assessment, and estimated radiation dose. In the water phantom, the asymmetric cone beam processing reduces exposure by approximately 20% with no change in image quality. The clinical coronary CTA patient groups had comparable demographics. The estimated dose reduction after implementation of the asymmetric approach was roughly 24% with no significant difference between the symmetric and asymmetric approach with respect to objective measures of image quality or subjective assessment using a four point scale. When compared to a symmetric approach...

Center-surround vs. distance-independent lateral connectivity in the olfactory bulb

Kim, David H.; Chang, Andrew Y.; McTavish, Thomas S.; Patel, Hetal K.; Willhite, David C.
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 31/05/2012 Português
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Lateral neuronal interactions are known to play important roles in sensory information processing. A center-on surround-off local circuit arrangement has been shown to play a role in mediating contrast enhancement in the visual, auditory, and somatosensory systems. The lateral connectivity and the influence of those connections have been less clear for the olfactory system. A critical question is whether the synaptic connections between the primary projection neurons, mitral and tufted (M/T) cells, and their main inhibitory interneurons, the granule cells (GCs), can support a center-surround motif. Here, we study this question by injecting a “center” in the glomerular layer of the olfactory bulb (OB) with a marker of synaptic connectivity, the pseudorabies virus (PRV), then examines the distribution of labeling in the “surround” of GCs. We use a novel method to score the degree to which the data fits a center-surround model vs. distance-independent connectivity. Data from 22 injections show that M/T cells generally form lateral connections with GCs in patterns that lie between the two extremes.

Retinal visual processing constrains human ocular following response

Sheliga, B. M.; Quaia, C.; FitzGibbon, E. J.; Cumming, B.G.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Português
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Ocular following responses (OFRs) are the initial tracking eye movements elicited at ultra-short latency by sudden motion of a textured pattern. We wished to evaluate quantitatively the impact that subcortical stages of visual processing might have on the OFRs. In three experiments we recorded the OFRs of human subjects to brief horizontal motion of 1D vertical sine-wave gratings restricted to an elongated horizontal aperture. Gratings were composed of a variable number of abutting horizontal strips where alternate strips were in counterphase. In one of the experiments we also utilized gratings occupying a variable number of horizontal strips separated vertically by mean-luminance gaps. We modeled retinal center/surround receptive fields as a difference of two 2-D Gaussian functions. When the characteristics of such local filters were selected in accord with the known properties of primate retinal ganglion cells, a single-layer model was capable to quantitatively account for the observed changes in the OFR amplitude for stimuli composed of counterphase strips of different heights (Experiment 1), for a wide range of stimulus contrasts (Experiment 2) and spatial frequencies (Experiment 3). A similar model using oriented filters that resemble cortical simple cells was also able to account for these data. Since similar filters can be constructed from the linear summation of retinal filters...

Motion Processing in the Larval Zebrafish Tectum

Grama, Abhinav Satish
Fonte: Harvard University Publicador: Harvard University
Tipo: Thesis or Dissertation; text Formato: application/pdf
Português
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Larval zebrafish are highly visual animals that display a diverse repertoire of visually guided behaviors. Five days after their birth, they start tracking and hunting moving prey, a behavior that likely requires underlying neural circuits to analyze motion. The optic tectum, the largest structure in the zebrafish brain, is known to be involved in prey capture behavior. The specific role of this structure in motion processing is still an open question. The larval tectum receives processed inputs from direction selective retinal ganglion cells (DSRGCs). How do these inputs influence the responses of tectal neurons? Do local tectal circuits further affect tectal responses to motion? To study this, we performed in vivo two-photon calcium imaging on populations of tectal neurons and in vivo whole cell recordings while presenting larvae with moving stimuli. We show that a substantial fraction of tectal neurons are sensitive to the direction and speed of moving stimuli. Direction selectivity (DS) in these neurons is weakly correlated with RGC inputs and strongly correlated with local inhibition. The inhibition comes from the null direction of the recorded neurons and appears to be mediated by direction selective inhibitory neurons. Our data demonstrates the presence of a tectal circuit for computing the direction of motion...

The Global Opportunity in IT-Based Services : Assessing and Enhancing Country Competitiveness

Sudan, Randeep; Ayers, Seth; Dongier, Philippe; Muente-Kunigami, Arturo; Qiang, Christine Zhen-Wei
Fonte: World Bank Publicador: World Bank
Português
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This book aims to help policy makers take advantage of the opportunities presented by increased cross-border trade in information technology (IT) services and IT-enabled services (ITES). It begins by defining the two industries and estimating the potential global market opportunities for trade in each. Then it discusses economic and other benefits for countries that succeed in these areas, along with factors crucial to the competitiveness of a country or location, including skills, cost advantages, infrastructure, and a hospitable business environment, and examines the potential competitiveness of small countries and of least developed countries specifically. The volume also discusses policy options for enabling growth in the IT services and ITES industries. Appendix A introduces the Location Readiness Index (LRI), a modeling tool to help countries assess their IT and ITES industries. Finally, appendix B presents an analysis of the IT and ITES industries in Indonesia and Kenya as an illustrative application of the LRI.

Bangladesh - Revenue Mobilization Program for Results: VAT Improvement Program Technical Assessment

World Bank
Fonte: Washington, DC Publicador: Washington, DC
Português
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This operation will support the VAT Improvement Program to assist the National Board of Revenue (NBR) in streamlining and modernizing Value Added Tax (VAT) operations and establishing an integrated VAT Management System for the purposes of implementing the new regime. The primary focus of the program is to prepare the administration to be able to administer the new VAT, which is to be introduced in July 2015. The new VAT Act, 2012 provides for a modern VAT scheme based on few exemptions and self-assessment. The Act provides the legal basis for the new VAT administration, and the impetus for a shift from manual to automated and modernized core tax business processing. The program is part of the government s broader tax reform agenda as articulated in the Tax Modernization Plan 2011-16 (endorsed by Parliament in June 2011), which envisages policy and institutional reform alongside a program for automating NBR operations to improve services to taxpayers, reduce administrative costs for taxpayers, and improve compliance. The VAT improvement program aims to widen the tax base by enhancing voluntary compliance...

Application-Specific Accelerators for Communications

Sun, Yang; Amiri, Kiarash; Brogioli, Michael; Cavallaro, Joseph R.
Fonte: Springer Science+Business Media, LLC Publicador: Springer Science+Business Media, LLC
Tipo: Parte de Livro
Português
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For computation-intensive digital signal processing algorithms, complexity is exceeding the processing capabilities of general-purpose digital signal processors (DSPs). In some of these applications, DSP hardware accelerators have been widely used to off-load a variety of algorithms from the main DSP host, including FFT, FIR/IIR filters, multiple-input multiple-output (MIMO) detectors, and error correction codes (Viterbi, Turbo, LDPC) decoders. Given power and cost considerations, simply implementing these computationally complex parallel algorithms with high-speed general-purpose DSP processor is not very efficient. However, not all DSP algorithms are appropriate for off-loading to a hardware accelerator. First, these algorithms should have data-parallel computations and repeated operations that are amenable to hardware implementation. Second, these algorithms should have a deterministic dataflow graph that maps to parallel datapaths. The accelerators that we consider are mostly coarse grain to better deal with streaming data transfer for achieving both high performance and low power. In this chapter, we focus on some of the basic and advanced digital signal processing algorithms for communications and cover major examples of DSP accelerators for communications.

Automatic processing of unattended lexical information in visual oddball presentation: neurophysiological evidence

Shtyrov, Yury; Goryainova, Galina; Tugin, Sergei; Ossadtchi, Alexey; Shestakova, Anna
Fonte: Frontiers Media S.A. Publicador: Frontiers Media S.A.
Tipo: Artigo de Revista Científica
Publicado em 09/08/2013 Português
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25.63%
Previous electrophysiological studies of automatic language processing revealed early (100–200 ms) reflections of access to lexical characteristics of speech signal using the so-called mismatch negativity (MMN), a negative ERP deflection elicited by infrequent irregularities in unattended repetitive auditory stimulation. In those studies, lexical processing of spoken stimuli became manifest as an enhanced ERP in response to unattended real words, as opposed to phonologically matched but meaningless pseudoword stimuli. This lexical ERP enhancement was explained by automatic activation of word memory traces realized as distributed strongly intra-connected neuronal circuits, whose robustness guarantees memory trace activation even in the absence of attention on spoken input. Such an account would predict the automatic activation of these memory traces upon any presentation of linguistic information, irrespective of the presentation modality. As previous lexical MMN studies exclusively used auditory stimulation, we here adapted the lexical MMN paradigm to investigate early automatic lexical effects in the visual modality. In a visual oddball sequence, matched short word and pseudoword stimuli were presented tachistoscopically in perifoveal area outside the visual focus of attention...

Spinal Cord Segmentation by One Dimensional Normalized Template Matching: A Novel, Quantitative Technique to Analyze Advanced Magnetic Resonance Imaging Data

Cadotte, Adam; Cadotte, David W.; Livne, Micha; Cohen-Adad, Julien; Fleet, David; Mikulis, David; Fehlings, Michael G.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/10/2015 Português
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Spinal cord segmentation is a developing area of research intended to aid the processing and interpretation of advanced magnetic resonance imaging (MRI). For example, high resolution three-dimensional volumes can be segmented to provide a measurement of spinal cord atrophy. Spinal cord segmentation is difficult due to the variety of MRI contrasts and the variation in human anatomy. In this study we propose a new method of spinal cord segmentation based on one-dimensional template matching and provide several metrics that can be used to compare with other segmentation methods. A set of ground-truth data from 10 subjects was manually-segmented by two different raters. These ground truth data formed the basis of the segmentation algorithm. A user was required to manually initialize the spinal cord center-line on new images, taking less than one minute. Template matching was used to segment the new cord and a refined center line was calculated based on multiple centroids within the segmentation. Arc distances down the spinal cord and cross-sectional areas were calculated. Inter-rater validation was performed by comparing two manual raters (n = 10). Semi-automatic validation was performed by comparing the two manual raters to the semi-automatic method (n = 10). Comparing the semi-automatic method to one of the raters yielded a Dice coefficient of 0.91 +/- 0.02 for ten subjects...

Temporal XML: Modeling, Indexing, and Query Processing

Rizzolo, Flavio; Vaisman, Alejandro
Fonte: SPRINGER Publicador: SPRINGER
Tipo: Artículo de revista
Português
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In this paper we address the problem of modeling and implementing temporal data in XML. We propose a data model for tracking historical information in an XML document and for recovering the state of the document as of any given time. We study the temporal constraints imposed by the data model, and present algorithms for validating a temporal XML document against these constraints, along with methods for fixing inconsistent documents. In addition, we discuss different ways of mapping the abstract representation into a temporal XML document, and introduce TXPath, a temporal XML query language that extends XPath 2.0. In the second part of the paper, we present our approach for summarizing and indexing temporal XML documents. In particular we show that by indexing continuous paths, i.e., paths that are valid continuously during a certain interval in a temporal XML graph, we can dramatically increase query performance. To achieve this, we introduce a new class of summaries, denoted TSummary, that adds the time dimension to the wellknown path summarization schemes. Within this framework, we present two new summaries: LCP and Interval summaries. The indexing scheme, denoted TempIndex, integrates these summaries with additional data structures. We give a query processing strategy based on TempIndex and a type of ancestor-descendant encoding...

The Complexity-Rate Tradeoff of Centralized Radio Access Networks

Rost, Peter; Talarico, Salvatore; Valenti, Matthew C.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Português
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In a centralized RAN, the signals from multiple RAPs are processed centrally in a data center. Centralized RAN enables advanced interference coordination strategies while leveraging the elastic provisioning of data processing resources. It is particularly well suited for dense deployments, such as within a large building where the RAPs are connected via fibre and many cells are underutilized. This paper considers the computational requirements of centralized RAN with the goal of illuminating the benefits of pooling computational resources. A new analytical framework is proposed for quantifying the computational load associated with the centralized processing of uplink signals in the presence of block Rayleigh fading, distance-dependent path-loss, and fractional power control. Several new performance metrics are defined, including computational outage probability, outage complexity, computational gain, computational diversity, and the complexity-rate tradeoff. The validity of the analytical framework is confirmed by comparing it numerically with a simulator compliant with the 3GPP LTE standard. Using the developed metrics, it is shown that centralizing the computing resources provides a higher net throughput per computational resource as compared to local processing.; Comment: 13 pages...

That's How We Roll: The NASA K2 Mission Science Products and Their Performance Metrics

Van Cleve, Jeffrey E.; Howell, Steve B.; Smith, Jeffrey C.; Clarke, Bruce D.; Thompson, Susan E.; Bryson, Stephen T.; Lund, Mikkel N.; Handberg, Rasmus; Chaplin, William J.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/12/2015 Português
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NASA's exoplanet Discovery mission Kepler was reconstituted as the K2 mission a year after the failure of the 2nd of Kepler's 4 reaction wheels in May 2013. The new spacecraft pointing method now gives typical roll motion of 1.0 pixels peak-to-peak over 6 hours at the edges of the field, two orders of magnitude greater than for Kepler. Despite these roll errors, the flight system and its modified science data processing pipeline restores much of the photometric precision of the primary mission while viewing a wide variety of targets, thus turning adversity into diversity. We define metrics for data compression and pixel budget available in each campaign; the photometric noise on exoplanet transit and stellar activity time scales; residual correlations in corrected long cadence light curves; and the protection of test sinusoidal signals from overfitting in the systematic error removal process. We find that data compression and noise both increase linearly with radial distance from the center of the field of view, with the data compression proportional to star count as well. At the center, where roll motion is nearly negligible, the limiting 6 hour photometric precision for a quiet 12th magnitude star can be as low as 30 ppm, only 25% higher than that of Kepler. This noise performance is achieved without sacrificing signal fidelity; test sinusoids injected into the data are attenuated by less than 10% for signals with periods up 15 days. At time scales relevant to asteroseismology...

A Processing Model for Free Word Order Languages

Rambow, Owen; Joshi, Aravind K.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 15/04/1995 Português
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Like many verb-final languages, Germn displays considerable word-order freedom: there is no syntactic constraint on the ordering of the nominal arguments of a verb, as long as the verb remains in final position. This effect is referred to as ``scrambling'', and is interpreted in transformational frameworks as leftward movement of the arguments. Furthermore, arguments from an embedded clause may move out of their clause; this effect is referred to as ``long-distance scrambling''. While scrambling has recently received considerable attention in the syntactic literature, the status of long-distance scrambling has only rarely been addressed. The reason for this is the problematic status of the data: not only is long-distance scrambling highly dependent on pragmatic context, it also is strongly subject to degradation due to processing constraints. As in the case of center-embedding, it is not immediately clear whether to assume that observed unacceptability of highly complex sentences is due to grammatical restrictions, or whether we should assume that the competence grammar does not place any restrictions on scrambling (and that, therefore, all such sentences are in fact grammatical), and the unacceptability of some (or most) of the grammatically possible word orders is due to processing limitations. In this paper...

Processing of 24 Micron Image Data at Spitzer Science Center

Masci, Frank J.; Laher, Russ; Fang, Fan; Fowler, John W.; Lee, Wen; Stolovy, Susan; Padgett, Deborah; Moshir, Mehrdad
Fonte: Astronomical Society of the Pacific Publicador: Astronomical Society of the Pacific
Tipo: Book Section; PeerReviewed Formato: application/pdf
Publicado em //2005 Português
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The 24μm array on board the Spitzer Space Telescope is one of three arrays in the Multi-band Imaging Photometer for Spitzer (MIPS) instrument. It provides 5′.3 × 5′.3 images at a scale of ≈ 2″.5 per pixel corresponding to sampling of the point spread function which is slightly better than critical (≈ 0.4λ / D). A scan-mirror allows dithering of images on the array without the overhead of moving and stabilizing the spacecraft. It also enables efficient mapping of large areas of sky without significant compromise in sensitivity. We present an overview of the pipeline flow and reduction steps involved in the processing of image data acquired with the 24μm array. Residual instrumental signatures not yet removed in automated processing and strategies for hands-on mitigation thereof are also given.