1000 resultados para LTER


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Computer vision is an attractive solution for uninhabited aerial vehicle (UAV) collision avoidance, due to the low weight, size and power requirements of hardware. A two-stage paradigm has emerged in the literature for detection and tracking of dim targets in images, comprising of spatial preprocessing, followed by temporal filtering. In this paper, we investigate a hidden Markov model (HMM) based temporal filtering approach. Specifically, we propose an adaptive HMM filter, in which the variance of model parameters is refined as the quality of the target estimate improves. Filters with high variance (fat filters) are used for target acquisition, and filters with low variance (thin filters) are used for target tracking. The adaptive filter is tested in simulation and with real data (video of a collision-course aircraft). Our test results demonstrate that our adaptive filtering approach has improved tracking performance, and provides an estimate of target heading not present in previous HMM filtering approaches.

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This work investigates the role of narrative literature in late-20th century and contemporary Anglo-American moral philosophy. It aims to show the trend of reading narrative literature for purposes of moral philosophy from the 1970 s and early 80 s to the present day as a part of a larger movement in Anglo-American moral philosophy, and to present a view of its significance for moral philosophy overall. Chapter 1 provides some preliminaries concerning the view of narrative literature which my discussion builds on. In chapter 2 I give an outline of how narrative literature is considered in contemporary Anglo-American moral philosophy, and connect this use to the broad trend of neo-Aristotelian ethics in this context. In chapter 3 I connect the use of literature to the idea of the non-generalizability of moral perception and judgment, which is central to the neo-Aristotelian trend, as well as to a range of moral particularisms and anti-theoretical positions of late 20th century and contemporary ethics. The joint task of chapters 2 and 3 is to situate the trend of reading narrative literature for the purposes of moral philosophy in the present context of moral philosophy. In the following two chapters, 4 and 5, I move on from the particularizing power of narrative literature, which is emphasized by neo-Aristotelians and particularists alike, to a broader under-standing of the intellectual potential of narrative literature. In chapter 4 I argue that narrative literature has its own forms of generalization which are enriching for our understanding of the workings of ethical generalizations in philosophy. In chapter 5 I discuss Iris Murdoch s and Martha Nussbaum s respective ways of combining ethical generality and particularity in a philosophical framework where both systematic moral theory and narrative literature are taken seriously. In chapter 6 I analyse the controversy between contemporary anti-theoretical conceptions of ethics and Nussbaum s refutation of these. I present my suggestion for how the significance of the ethics/literature discussion for moral philosophy can be understood if one wants to overcome the limitations of both Nussbaum s theory-centred, equilibrium-seeking perspective, and the anti-theorists repudiation of theory. I call my position the inclusive approach .

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What are the musical features that turn a song into a hit? The aim of this research is to explore the musical features of hit tunes by studying the 224 most popular Finnish evergreens from the 1930s to the 1990s. It is remarkable, that 80-90% of Finnish oldies are in a minor key, though parallel major keys have also been widely employed within single pieces through, for example, modulations. Furthermore, melodies are usually diatonic, staying mostly in the same key. Consequently, chromatically altered tones in the melody and short modulations in the bridge sections become more prominent. I have concentrated in particular on the melodic lines in order to find the most typical melodic formulas from the data. These analyzed melodic formulas play an important role, because they serve as leading phrases and punchlines in songs. Analysis has revealed three major melodic formulas, which most often appear in the melodic lines of hit tunes. All of these formulas share common thematic ground, because they originate from the triadic tonic chord. Because the tonic chord is the most conventional opening chord in the verse parts, it is logical that these formulas occur most often in verses. The strong dominance of these formulas is very much a result of the rhythmic flexibility they possess; for instance, they can be found in every musical style from waltz to foxtrot. Alongside the major formulas lies a miscellaneous group of other tonic-related melodic formulas. One group of melodic formulas consists of melodic quotations. These quotations appear in a different musical context, for instance in a harmonically altered form, and are therefore often difficult to recognize as such. Yet despite the contextual manipulation, the distinctive character of the cited melody usually remains the same. Composers have also made use of certain popular chord-progressions in order to create new but familiar-sounding melodies. The most important individual progression in this case is what is known as a "circle of fifths" and its shortened, prolonged and altered versions. Because that progression is harmonically strong, it is also a contrastive tool used especially in chorus parts and middle sections (AABA). I have also paid attention to ragtime and jazz influences, which can be found in harmony parts and certain melody notes, which extend, suspend or alter the accompaning chords. Other influences from jazz and ragtime in the Finnish evergreen are evident in the use of typical Tin Pan Alley popular song forms. The most important is the AABA form, which dominates over the data along with the verse/chorus-type popular song form. To briefly illustrate the main results, the basic concept of the hit tune can be traced back to Tin Pan Alley songs, whereas the major stylistic aspects, such as minor keys and musical styles, bear influences from Russian, Western European, and Finnish traditions.

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I denna avhandling undersöker jag hur modersmålslärare inom den grundläggande utbildningen (åk 7–9) undervisar i litteratur. De frågor jag ställer mig är: Hur förverkligar lärarna sin litteraturundervisning i praktiken, hur förhåller de sig till den nya läroplanen i ämnet, Grunderna för läroplanen för den grundläggande utbildningen 2004, samt med vilken ämnes-, litteratur- och kunskapssyn utgår de från i sin undervisning? Undersökningsresultatet analyseras utifrån läroplan och utifrån en läsarorienterad, sociokulturell och funktionell litteratursyn och litteraturpedagogik. Undersökningen är kvalitativ och riktar sig i form av ett frågeformulär till alla modersmålslärare i högstadierna i huvudstadsregionen. Tretton lärare deltar slutligen och åtta av dessa svar uppföljs genom en tematisk intervju. Undersökningen sker våren 2005. Forskningsresultatet visar på att flera av lärarna till stor del bygger upp sin undervisning utifrån färdiga uppgifter och koncept och att undervisningen styrs av metoden, av frågan hur. Dessa lärares undervisning sker således inte utgående från en enhetlig ämnes-, litteratur- och kunskapssyn, utan ämnessynen varierar beroende på uppgift. Recensionen är den arbetsuppgift som är vanligast bland lärarna, även om flera lärare ställer sig tveksamma till den. Övriga uppgifter som förekommer bland flera lärare är uppgiftskoncept kring klassiker och litterära samtal inför klass. Tematisk litteraturundervisning används även av flera lärare, liksom Netlibris, som innebär att två klasser från olika skolor över nätet diskuterar en skönlitterär text. Både Netlibris och tematisk litteraturundervisning är metoder som lärarna förhåller sig positiva till och ser pedagogiska fördelar med. Den tematiska undervisningen sker emellertid ofta i form av koncept som återkommer i samma form år efter år. Två lärare strävar dock efter att arbeta utifrån en enhetlig ämnessyn – den erfarenhetspedagogiska. Dessa lärare använder sig av färre koncept i sin undervisning. De bygger snarare upp sin undervisning utifrån frågan varför än hur, vilket innebär att de i högre grad har möjlighet att beakta elevernas intressen och behov i utformandet av undervisningen. Detta syns bland annat i valet av böcker och teman. En av dessa lärare använder sig även av portfölj- och loggboksmetodik och låter, i enlighet med läroplanen, eleverna själva vara med och utvärdera undervisningen och den egna utvecklingen. Lärarna verkar överlag förhålla sig mera positiva till de uppgifter som bygger på dialog och som tar fasta på läsaren i läsprocessen. Trots att lärarna betonar dialogens betydelse i litteraturundervisningen, bygger undervisningen ändå ofta, och i flera fall helt och hållet, på uppgifter som saknar dialog. En av orsakerna till detta kan vara att gamla koncept, trots nya uppgifter, lever kvar i undervisningen. Att lärarna framhåller de uppgifter som utgår från läsning av gemensamma texter och som tar fasta på en läsarorienterad och sociokulturell litteratursyn, visar dock på att de nya uppgifterna håller på att omkullkasta de gamla; lärarnas litteraturundervisning befinner sig således i förändring. Samtliga lärare förhåller sig positiva till litteraturundervisning och framhåller att litteraturen sedan deras egen skoltid fått en mera framträdande roll i undervisningen. De påpekar också att modersmålsundervisningen idag är mindre färdighetsinriktad och går mot en ökad dialog.

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- Background Following Kapur’s hypothesis [1] that schizophrenia is the intensification of phenomenological experience caused by the upregulation of dopamine, a survey of observed dopamine responses to phenomenal information was conducted. - Method An integrative study. - Results When considered in the light of the ecological theory of perception (ETP) [2] and global workspace theory (GBT) [3] Kapur’s hypothesis makes sense: Both the ETP and the GBT require an agent to attribute salience to perceptual information in order to filter an infinite array of available information and usefully sort information by importance. Dopamine may be the primary agent for this purpose. Thus perception itself is suspected as being a dopamine-mediated, and the symptoms and signs of schizophrenia may therefore be the result of dopamine dysfunction. - Conclusions The application of both ETP and GBT to the dopamine hypothesis gives the hypothesis a much-needed causal mechanism and the confl uence of these theories also provides ETP with a neurological perceptual fi lter. This paper provides a compelling model for schizophrenia; a hypothesis that ties perceptual theory to Kapur ’ s concept of dopamine-mediated salience.

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Controlled nuclear fusion is one of the most promising sources of energy for the future. Before this goal can be achieved, one must be able to control the enormous energy densities which are present in the core plasma in a fusion reactor. In order to be able to predict the evolution and thereby the lifetime of different plasma facing materials under reactor-relevant conditions, the interaction of atoms and molecules with plasma first wall surfaces have to be studied in detail. In this thesis, the fundamental sticking and erosion processes of carbon-based materials, the nature of hydrocarbon species released from plasma-facing surfaces, and the evolution of the components under cumulative bombardment by atoms and molecules have been investigated by means of molecular dynamics simulations using both analytic potentials and a semi-empirical tight-binding method. The sticking cross-section of CH3 radicals at unsaturated carbon sites at diamond (111) surfaces is observed to decrease with increasing angle of incidence, a dependence which can be described by a simple geometrical model. The simulations furthermore show the sticking cross-section of CH3 radicals to be strongly dependent on the local neighborhood of the unsaturated carbon site. The erosion of amorphous hydrogenated carbon surfaces by helium, neon, and argon ions in combination with hydrogen at energies ranging from 2 to 10 eV is studied using both non-cumulative and cumulative bombardment simulations. The results show no significant differences between sputtering yields obtained from bombardment simulations with different noble gas ions. The final simulation cells from the 5 and 10 eV ion bombardment simulations, however, show marked differences in surface morphology. In further simulations the behavior of amorphous hydrogenated carbon surfaces under bombardment with D^+, D^+2, and D^+3 ions in the energy range from 2 to 30 eV has been investigated. The total chemical sputtering yields indicate that molecular projectiles lead to larger sputtering yields than atomic projectiles. Finally, the effect of hydrogen ion bombardment of both crystalline and amorphous tungsten carbide surfaces is studied. Prolonged bombardment is found to lead to the formation of an amorphous tungsten carbide layer, regardless of the initial structure of the sample. In agreement with experiment, preferential sputtering of carbon is observed in both the cumulative and non-cumulative simulations

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Föreliggande arbete är resultatet av ett experiment med en materialinsamlingsmetod. Vad händer om man lägger ut en enkät med frågor om språk på webben och låter den som vill leverera svar? Vilka är det som svarar och vad har respondentgruppens sammansättning för betydelse för resultatet, dvs. kan man lita på det och i vilken utsträckning i så fall? Kan en kvantitativ vinst, då många svarar, täcka en eventuell kvalitativ förlust, då man inte har kontroll över vilka de många är? Man anar att svarsmönstret med nödvändighet måste vara brokigt och strävar att täcka in så mycket av det som möjligt och då är webbalternativet värt att pröva på. Tanken att ta reda på vad språkbrukarna själva har för syn på sitt språk, och vad de har för synpunkter bl.a. på språkvården, var egentligen inte ny, men den hade fått ny aktualitet i samband med arbetet med Svenska språknämndens handlingsprogram för svenskan i Finland (Tänk om ... 2003). Webbenkäten är uppgjord så att den matchar en liknande undersökning som genomfördes som en traditionell postenkät 30 år tidigare. Webbenkäten gav många svar och respondenterna representerade många olika språkmiljöer. Det fanns fler likheter än olikheter mellan svaren i webbenkäten 2002 och i enkätundersökningen 1972. En skillnad som dock märktes var att respondenterna i dag inte uppfattar svenskan i Finland som ålderdomlig, utan snarare karaktäriserar den som finskpåverkad. En påfallande likhet var känslan för det mest finlandssvenska, nämligen de specifikt finlandssvenska orden och uttrycken samt inslagen av finlandssvensk dialekt.

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Since the inception of the LTER Program in 1980, climate has been studied at individual LTER sites and an LTER Climate Committee has been responsible for inter-site activities. At individual sites, climate studies support ecological research, emphasize inter-site heterogeneity, and often relate to other national monitoring and research programs. In inter-site work, the Climate Committee has produced protocols for meteorological observations, described and compared climates of the first 11 sites, and raised important issues regarding climate variability and ecosystem response.

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The 1992 PACLIM meeting featured the Long-Term Ecological Research (LTER) program, sponsored by the National Science Foundation. Ranging from hot to cold and wet to dry climatic regimes, these 18 sites are attempting to understand the web of relationships in different locations as communities evolve over time scales of years to decades to centuries. During this time they are subject to external forcings, including those that vary smoothly and somewhat predictably, like the seasons, upon which are superimposed random "shocks" of various magnitudes.

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H.J. Andrews Experimental Forest is a 6400 ha forest of Douglas fir, western hemlock, and Pacific silver fir located in, and typical of, the central portion of the western slope of the Cascade mountain range of Oregon. The forest is one of 19 sites in the Long-Term Ecological Research (LTER) program sponsored by the National Science Foundation. ... Because of the scientific significance of Andrews Forest, it is important to investigate the temporal variability of annual and seasonal temperature and precipitation values at the site and identify past times of anomalous climatic conditions. It is also important to establish quantitatively the relationships between the climate of Andrews Forest and that of its surrounding area and, hence, place the climate of Andrews Forest into its regional context.

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We present a broadly tunable active mode- locked. bre ring laser based on a semiconductor optical ampli. er ( SOA), with forward injection optical pulses. The laser can generate pulse sequence with pulsewidth about 12 ps and high output power up to 8.56dBm at 2.5 GHz stably. Incorporated with a wavelength- tunable optical bandpass. lter, the pulse laser can operate with a broad wavelength tunable span up to 37nm with almost constant pulsewidth. A detailed experimental analysis is also carried out to investigate the relationship between the power of the internal cavity and the pulsewidth of the output pulse sequence. The experimental con. guration of the pulse laser is very simple and easy to setup with no polarization- sensitive components.

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High resolution studies of a0/f0(980) decays into channels involving open strangeness are currently being performed at COSY-Jülich. As a “filter” for isospin-zero intermediate states, i.e. to selectively produce the f0(980) resonance, the dd→αK+K− reaction was measured with the magnetic ANKE spectrometer. In order to determine the luminosity of this experiment, the elastically and quasi-elastically scattered deuterons were recorded simultaneously with the αK+K− events. Here we report about the luminosity determination via investigating the (quasi-) elastic deuterons at ANKE.