809 resultados para Multi-dimensional Numbered Information Spaces
Resumo:
Klimamontoring benötigt eine operative, raum-zeitliche Analyse der Klimavariabilität. Mit dieser Zielsetzung, funktionsbereite Karten regelmäßig zu erstellen, ist es hilfreich auf einen Blick, die räumliche Variabilität der Klimaelemente in der zeitlichen Veränderungen darzustellen. Für aktuelle und kürzlich vergangene Jahre entwickelte der Deutsche Wetterdienst ein Standardverfahren zur Erstellung solcher Karten. Die Methode zur Erstellung solcher Karten variiert für die verschiedenen Klimaelemente bedingt durch die Datengrundlage, die natürliche Variabilität und der Verfügbarkeit der in-situ Daten.rnIm Rahmen der Analyse der raum-zeitlichen Variabilität innerhalb dieser Dissertation werden verschiedene Interpolationsverfahren auf die Mitteltemperatur der fünf Dekaden der Jahre 1951-2000 für ein relativ großes Gebiet, der Region VI der Weltorganisation für Meteorologie (Europa und Naher Osten) angewendet. Die Region deckt ein relativ heterogenes Arbeitsgebiet von Grönland im Nordwesten bis Syrien im Südosten hinsichtlich der Klimatologie ab.rnDas zentrale Ziel der Dissertation ist eine Methode zur räumlichen Interpolation der mittleren Dekadentemperaturwerte für die Region VI zu entwickeln. Diese Methode soll in Zukunft für die operative monatliche Klimakartenerstellung geeignet sein. Diese einheitliche Methode soll auf andere Klimaelemente übertragbar und mit der entsprechenden Software überall anwendbar sein. Zwei zentrale Datenbanken werden im Rahmen dieser Dissertation verwendet: So genannte CLIMAT-Daten über dem Land und Schiffsdaten über dem Meer.rnIm Grunde wird die Übertragung der Punktwerte der Temperatur per räumlicher Interpolation auf die Fläche in drei Schritten vollzogen. Der erste Schritt beinhaltet eine multiple Regression zur Reduktion der Stationswerte mit den vier Einflussgrößen der Geographischen Breite, der Höhe über Normalnull, der Jahrestemperaturamplitude und der thermischen Kontinentalität auf ein einheitliches Niveau. Im zweiten Schritt werden die reduzierten Temperaturwerte, so genannte Residuen, mit der Interpolationsmethode der Radialen Basis Funktionen aus der Gruppe der Neuronalen Netzwerk Modelle (NNM) interpoliert. Im letzten Schritt werden die interpolierten Temperaturraster mit der Umkehrung der multiplen Regression aus Schritt eins mit Hilfe der vier Einflussgrößen auf ihr ursprüngliches Niveau hochgerechnet.rnFür alle Stationswerte wird die Differenz zwischen geschätzten Wert aus der Interpolation und dem wahren gemessenen Wert berechnet und durch die geostatistische Kenngröße des Root Mean Square Errors (RMSE) wiedergegeben. Der zentrale Vorteil ist die wertegetreue Wiedergabe, die fehlende Generalisierung und die Vermeidung von Interpolationsinseln. Das entwickelte Verfahren ist auf andere Klimaelemente wie Niederschlag, Schneedeckenhöhe oder Sonnenscheindauer übertragbar.
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Screening people without symptoms of disease is an attractive idea. Screening allows early detection of disease or elevated risk of disease, and has the potential for improved treatment and reduction of mortality. The list of future screening opportunities is set to grow because of the refinement of screening techniques, the increasing frequency of degenerative and chronic diseases, and the steadily growing body of evidence on genetic predispositions for various diseases. But how should we decide on the diseases for which screening should be done and on recommendations for how it should be implemented? We use the examples of prostate cancer and genetic screening to show the importance of considering screening as an ongoing population-based intervention with beneficial and harmful effects, and not simply the use of a test. Assessing whether screening should be recommended and implemented for any named disease is therefore a multi-dimensional task in health technology assessment. There are several countries that already use established processes and criteria to assess the appropriateness of screening. We argue that the Swiss healthcare system needs a nationwide screening commission mandated to conduct appropriate evidence-based evaluation of the impact of proposed screening interventions, to issue evidence-based recommendations, and to monitor the performance of screening programmes introduced. Without explicit processes there is a danger that beneficial screening programmes could be neglected and that ineffective, and potentially harmful, screening procedures could be introduced.
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It has been suggested that there are several distinct phenotypes of childhood asthma or childhood wheezing. Here, we review the research relating to these phenotypes, with a focus on the methods used to define and validate them. Childhood wheezing disorders manifest themselves in a range of observable (phenotypic) features such as lung function, bronchial responsiveness, atopy and a highly variable time course (prognosis). The underlying causes are not sufficiently understood to define disease entities based on aetiology. Nevertheless, there is a need for a classification that would (i) facilitate research into aetiology and pathophysiology, (ii) allow targeted treatment and preventive measures and (iii) improve the prediction of long-term outcome. Classical attempts to define phenotypes have been one-dimensional, relying on few or single features such as triggers (exclusive viral wheeze vs. multiple trigger wheeze) or time course (early transient wheeze, persistent and late onset wheeze). These definitions are simple but essentially subjective. Recently, a multi-dimensional approach has been adopted. This approach is based on a wide range of features and relies on multivariate methods such as cluster or latent class analysis. Phenotypes identified in this manner are more complex but arguably more objective. Although phenotypes have an undisputed standing in current research on childhood asthma and wheezing, there is confusion about the meaning of the term 'phenotype' causing much circular debate. If phenotypes are meant to represent 'real' underlying disease entities rather than superficial features, there is a need for validation and harmonization of definitions. The multi-dimensional approach allows validation by replication across different populations and may contribute to a more reliable classification of childhood wheezing disorders and to improved precision of research relying on phenotype recognition, particularly in genetics. Ultimately, the underlying pathophysiology and aetiology will need to be understood to properly characterize the diseases causing recurrent wheeze in children.
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Recurrence of cardiovascular events and mortality remain high after acute coronary syndromes. A Swiss multicentric study, "Inflammation and acute coronary syndromes (ACS)--Novel strategies for prevention and clinical managements", is currently underway with the support of the Swiss National Science Foundation. The study includes a clinical research subproject of which the aim is to assess the impact of the ELIPS program (multi-dimEnsionaL prevention Program after acute coronary Syndrome) on the recurrence of cardiovascular events after an ACS. The basic research sub-projects aim to investigate novel cardiovascular risk biomarkers and genetic determinants of recurrence and to study the role of stem cells after an ACS. Another sub-project will evaluate intracoronary imaging techniques and the efficacy of different types of stents.
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Natural methane (CH4) emissions from wet ecosystems are an important part of today's global CH4 budget. Climate affects the exchange of CH4 between ecosystems and the atmosphere by influencing CH4 production, oxidation, and transport in the soil. The net CH4 exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, the LPJ-WHyMe global dynamical vegetation model is used to simulate global net CH4 emissions for different ecosystems: northern peatlands (45°–90° N), naturally inundated wetlands (60° S–45° N), rice agriculture and wet mineral soils. Mineral soils are a potential CH4 sink, but can also be a source with the direction of the net exchange depending on soil moisture content. The geographical and seasonal distributions are evaluated against multi-dimensional atmospheric inversions for 2003–2005, using two independent four-dimensional variational assimilation systems. The atmospheric inversions are constrained by the atmospheric CH4 observations of the SCIAMACHY satellite instrument and global surface networks. Compared to LPJ-WHyMe the inversions result in a~significant reduction in the emissions from northern peatlands and suggest that LPJ-WHyMe maximum annual emissions peak about one month late. The inversions do not put strong constraints on the division of sources between inundated wetlands and wet mineral soils in the tropics. Based on the inversion results we diagnose model parameters in LPJ-WHyMe and simulate the surface exchange of CH4 over the period 1990–2008. Over the whole period we infer an increase of global ecosystem CH4 emissions of +1.11 Tg CH4 yr−1, not considering potential additional changes in wetland extent. The increase in simulated CH4 emissions is attributed to enhanced soil respiration resulting from the observed rise in land temperature and in atmospheric carbon dioxide that were used as input. The long-term decline of the atmospheric CH4 growth rate from 1990 to 2006 cannot be fully explained with the simulated ecosystem emissions. However, these emissions show an increasing trend of +3.62 Tg CH4 yr−1 over 2005–2008 which can partly explain the renewed increase in atmospheric CH4 concentration during recent years.
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The aim of this study was to refine a multi-dimensional scale based on physiological and behavioural parameters, known as the post abdominal surgery pain assessment scale (PASPAS), to quantify pain after laparotomy in horses. After a short introduction, eight observers used the scale to assess eight horses at multiple time points after laparotomy. In addition, a single observer was used to test the correlation of each parameter with the total pain index in 34 patients, and the effect of general anaesthesia on PASPAS was investigated in a control group of eight horses. Inter-observer variability was low (coefficient of variation 0.3), which indicated good reliability of PASPAS. The correlation of individual parameters with the total pain index differed between parameters. PASPAS, which was not influenced by general anaesthesia, was a useful tool to evaluate pain in horses after abdominal surgery and may also be useful to investigate analgesic protocols or for teaching purposes.
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Our research explored the influence of deer and gap size on nitrogen cycling, soil compaction, and vegetation trajectories in twelve canopy gaps of varying sizes in a hemlock-northern hardwood forest. Each gap contained two fenced and two unfenced plots. Gap size, soil compaction, winter deer use, and available nitrogen were measured in 2011. Vegetation was assessed in 2007 and 2011, and non-metric multi-dimensional scaling was used to determine vegetative change. Results show that winter deer use was greater in smaller gaps. Deer accessibility did not influence compaction but did significantly increase total available nitrogen in April. April ammonium, April nitrate, and May nitrate were positively related to gap size. The relationship between gap size and vegetative community change was positive for fenced plots but unrelated for unfenced plots. In conclusion, deer are positively contributing to nitrogen dynamics and altering the relationship between canopy gap size and vegetative community change.
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Approximately 90% of fine aerosol in the Midwestern United States has a regional component with a sizable fraction attributed to secondary production of organic aerosol (SOA). The Ozark Forest is an important source of biogenic SOA precursors like isoprene (> 150 mg m-2 d-1), monoterpenes (10-40 mg m-2 d-1), and sesquiterpenes (10-40 mg m-2d-1). Anthropogenic sources include secondary sulfate and nitrate and biomass burning (51-60%), vehicle emissions (17-26%), and industrial emissions (16-18%). Vehicle emissions are an important source of volatile and vapor-phase, semivolatile aliphatic and aromatic hydrocarbons that are important anthropogenic sources of SOA precursors. The short lifetime of SOA precursors and the complex mixture of functionalized oxidation products make rapid sampling, quantitative processing methods, and comprehensive organic molecular analysis essential elements of a comprehensive strategy to advance understanding of SOA formation pathways. Uncertainties in forecasting SOA production on regional scales are large and related to uncertainties in biogenic emission inventories and measurement of SOA yields under ambient conditions. This work presents a bottom-up approach to develop a conifer emission inventory based on foliar and cortical oleoresin composition, development of a model to estimate terpene and terpenoid signatures of foliar and bole emissions from conifers, development of processing and analytic techniques for comprehensive organic molecular characterization of SOA precursors and oxidation products, implementation of the high-volume sampling technique to measure OA and vapor-phase organic matter, and results from a 5 day field experiment conducted to evaluate temporal and diurnal trends in SOA precursors and oxidation products. A total of 98, 115, and 87 terpene and terpenoid species were identified and quantified in commercially available essential oils of Pinus sylvestris, Picea mariana, and Thuja occidentalis, respectively, by comprehensive, two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC-ToF-MS). Analysis of the literature showed that cortical oleoresin composition was similar to foliar composition of the oldest branches. Our proposed conceptual model for estimation of signatures of terpene and terpenoid emissions from foliar and cortical oleoresin showed that emission potentials of the foliar and bole release pathways are dissimilar and should be considered for conifer species that develop resin blisters or are infested with herbivores or pathogens. Average derivatization efficiencies for Methods 1 and 2 were 87.9 and 114%, respectively. Despite the lower average derivatization efficiency of Method 1, distinct advantages included a greater certainty of derivatization yield for the entire suite of multi- and poly-functional species and fewer processing steps for sequential derivatization. Detection limits for Method 1 using GC × GC- ToF-MS were 0.09-1.89 ng μL-1. A theoretical retention index diagram was developed for a hypothetical GC × 2GC analysis of the complex mixture of SOA precursors and derivatized oxidation products. In general, species eluted (relative to the alkyl diester reference compounds) from the primary column (DB-210) in bands according to n and from the secondary columns (BPX90, SolGel-WAX) according to functionality, essentially making the GC × 2GC retention diagram a Carbon number-functionality grid. The species clustered into 35 groups by functionality and species within each group exhibited good separation by n. Average recoveries of n-alkanes and polyaromatic hydrocarbons (PAHs) by Soxhlet extraction of XAD-2 resin with dichloromethane were 80.1 ± 16.1 and 76.1 ± 17.5%, respectively. Vehicle emissions were the common source for HSVOCs [i.e., resolved alkanes, the unresolved complex mixture (UCM), alkylbenzenes, and 2- and 3-ring PAHs]. An absence of monoterpenes at 0600-1000 and high concentrations of monoterpenoids during the same period was indicative of substantial losses of monoterpenes overnight and the early morning hours. Post-collection, comprehensive organic molecular characterization of SOA precursors and products by GC × GC-ToFMS in ambient air collected with ~2 hr resolution is a promising method for determining biogenic and anthropogenic SOA yields that can be used to evaluate SOA formation models.
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The demands of developing modern, highly dynamic applications have led to an increasing interest in dynamic programming languages and mechanisms. Not only applications must evolve over time, but the object models themselves may need to be adapted to the requirements of different run-time contexts. Class-based models and prototype-based models, for example, may need to co-exist to meet the demands of dynamically evolving applications. Multi-dimensional dispatch, fine-grained and dynamic software composition, and run-time evolution of behaviour are further examples of diverse mechanisms which may need to co-exist in a dynamically evolving run-time environment How can we model the semantics of these highly dynamic features, yet still offer some reasonable safety guarantees? To this end we present an original calculus in which objects can adapt their behaviour at run-time to changing contexts. Both objects and environments are represented by first-class mappings between variables and values. Message sends are dynamically resolved to method calls. Variables may be dynamically bound, making it possible to model a variety of dynamic mechanisms within the same calculus. Despite the highly dynamic nature of the calculus, safety properties are assured by a type assignment system.
Resumo:
The demands of developing modern, highly dynamic applications have led to an increasing interest in dynamic programming languages and mechanisms. Not only must applications evolve over time, but the object models themselves may need to be adapted to the requirements of different run-time contexts. Class-based models and prototype-based models, for example, may need to co-exist to meet the demands of dynamically evolving applications. Multi-dimensional dispatch, fine-grained and dynamic software composition, and run-time evolution of behaviour are further examples of diverse mechanisms which may need to co-exist in a dynamically evolving run-time environment. How can we model the semantics of these highly dynamic features, yet still offer some reasonable safety guarantees? To this end we present an original calculus in which objects can adapt their behaviour at run-time. Both objects and environments are represented by first-class mappings between variables and values. Message sends are dynamically resolved to method calls. Variables may be dynamically bound, making it possible to model a variety of dynamic mechanisms within the same calculus. Despite the highly dynamic nature of the calculus, safety properties are assured by a type assignment system.
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Context-dependent behavior is becoming increasingly important for a wide range of application domains, from pervasive computing to common business applications. Unfortunately, mainstream programming languages do not provide mechanisms that enable software entities to adapt their behavior dynamically to the current execution context. This leads developers to adopt convoluted designs to achieve the necessary runtime flexibility. We propose a new programming technique called Context-oriented Programming (COP) which addresses this problem. COP treats context explicitly, and provides mechanisms to dynamically adapt behavior in reaction to changes in context, even after system deployment at runtime. In this paper we lay the foundations of COP, show how dynamic layer activation enables multi-dimensional dispatch, illustrate the application of COP by examples in several language extensions, and demonstrate that COP is largely independent of other commitments to programming style.
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Under the Constitution, the equality principle is very important in the Netherlands. This article argues that there is little evidence for equal citizenship in the Netherlands. There is anti-discrimination legislation in the Netherlands, but it is not very robust. The core argument in this article is that the equality principle must be supplemented by the diversity principle. Diversity is multi-dimensional and can refer to religion, philosophy of life, political persuasion, race (ethnicity), gender, nationality, sexual orientation, age, disability and chronic illness. In this paper multi-culturalism and disability are taken into account and we make a comparison of the social position of disabled people and people from ethnic minorities. Policies on diversity are needed to arrive at diverse citizenship in a varied society. This implies that a distinction has to be made between political citizenship and cultural citizenship. The former has to do with equality, and the latter with diversity.
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While spoken codeswitching (CS) among Latinos has received significant scholarly attention, few studies have examined written CS, specifically naturally-occurring CS in email. This study contributes to an under-studied area of Latino linguistic practices by reporting the results of a study of CS in the emails of five Spanish-English bilingual Latinos. Methods are employed that are not often used in discourse analysis of email texts, namely multi-dimensional scaling and tree diagrams, to explore the contextual parameters of written Spanish-English CS systematically. Consistent with the findings of other studies of CS in CMC, English use was most associated with professional or formal contacts, and use of Spanish, the participants’ native language, was linked to intimacy, informality, and group identification. Switches to Spanish functioned to personalize otherwise transactional or work-related English-dominant emails. The article also discusses novel orthographic and linguistic forms specific to the CMC context.
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In the first decades of the 20th century, aerological observations were for the first time performed in tropical regions. One of the most prominent endeavours in this respect was ARTHUR BERSON’s aerological expedition to East Africa. Although the main target was the East African monsoon circulation, the expedition provided also other insights that profoundly changed meteorology and climatology. BERSON observed that the tropical tropopause was much higher and colder than that over midlatitudes. Moreover, westerly winds were observed in the lower stratosphere, apparently contradicting the high-altitude equatorial easterly winds that were known since the Krakatoa eruption (‘‘Krakatoa easterlies’’). The puzzle was only resolved five decades later with the discovery of the Quasi-Biennial Oscillation (QBO). In this paper we briefly summarize the expedition of BERSON and review the results in a historical context and in the light of the current research. In the second part of the paper we re-visit BERSON’s early aerological observations, which we have digitized. We compare the observed wind profiles with corresponding profiles extracted from the ‘‘Twentieth Century Reanalysis’’, which provides global three-dimensional weather information back to 1871 based on an assimilation of sea-level and surface pressure data. The comparison shows a good agreement at the coast but less good agreement further inland, at the shore of Lake Victoria, where the circulation is more complex. These results demonstrate that BERSON’s observations are still valuable today as input to current reanalysis systems or for their validation.
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Greedy routing can be used in mobile ad-hoc networks as geographic routing protocol. This paper proposes to use greedy routing also in overlay networks by positioning overlay nodes into a multi-dimensional Euclidean space. Greedy routing can only be applied when a routing decision makes progress towards the final destination. Our proposed overlay network is built such that there will be always progress at each forwarding node. This is achieved by constructing at each node a so-called nearest neighbor convex set (NNCS). NNCSs can be used for various applications such as multicast routing, service discovery and Quality-of-Service routing. NNCS has been compared with Pastry, another topology-aware overlay network. NNCS has superior relative path stretches indicating the optimality of a path.