19 resultados para objectivity without objects

em Helda - Digital Repository of University of Helsinki


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We present results of a search for anomalous production of two photons together with an electron, muon, $\tau$ lepton, missing transverse energy, or jets using $p\bar{p}$ collision data from 1.1-2.0 fb$^{-1}$ of integrated luminosity collected by the Collider Detector at Fermilab (CDF). The event yields and kinematic distributions are examined for signs of new physics without favoring a specific model of new physics. The results are consistent with the standard model expectations. The search employs several new analysis techniques that significantly reduce instrumental backgrounds in channels with an electron and missing transverse energy.

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This dissertation is a study of the forms and functions of feasts and feasting in the ancient Egyptian village of Deir el-Medina in Thebes (modern Luxor). This particular village, during the New Kingdom (c. 1550 1069 BC), was inhabited by the men (and their families) who constructed the Royal Tombs in the Valley of the Kings and the Valley of the Queens. The royal artisans were probably more literate than the average Egyptians and the numerous Ramesside Period (c. 1295 1069 BC) non-literary texts found in the excavations of the village and its surroundings form the source material for this study. In this study, the methods used are mainly Egyptological and the references to feasts and feasting are considered in view of what is known of New Kingdom Egypt, Thebes, and Deir el-Medina. Nevertheless, it is the use of the methodological concept local vernacular religion that has resulted in the division of the research findings into two sections, i.e., references to feasts celebrated both in and outside the community and other references to feasts and feasting in the village. When considering the function of the feasts celebrated at Deir el-Medina, a functional approach to feasts introduced by anthropologists and archaeologists is utilized. The Deir el-Medina feasts which were associated with the official religion form a festival calendar of feasts celebrated annually on the same civil calendar day. The reconstructed festival calendar of Deir el-Medina reflects the feasts celebrated around Thebes or, at least, in Western Thebes. The function of the nationally and regionally observed feasts (which, at least at Deir el-Medina, resulted in a work-free day) may have been to keep people content so that they would continue to work which was to the advantage of the king and the elite surrounding him. Local feasts appear to have been observed more irregularly at Deir el-Medina or perhaps according to the lunar calendar. Feasts celebrated by the community as a whole served to maintain the unity of the group. In addition to feasts celebrated by the entire community, the inhabitants of Deir el-Medina could mark their own personal feasts and organize small gatherings during public feasts. Through such feasts, an individual man might form alliances and advance his chances of a favourable marriage or of acquiring a position on the work crew.

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The human visual system has adapted to function in different lighting environments and responds to contrast instead of the amount of light as such. On the one hand, this ensures constancy of perception, for example, white paper looks white both in bright sunlight and in dim moonlight, because contrast is invariant to changes in overall light level. On the other hand, the brightness of the surfaces has to be reconstructed from the contrast signal because no signal from surfaces as such is conveyed to the visual cortex. In the visual cortex, the visual image is decomposed to local features by spatial filters that are selective for spatial frequency, orientation, and phase. Currently it is not known, however, how these features are subsequently integrated to form objects and object surfaces. In this thesis the integration mechanisms of achromatic surfaces were studied by psychophysically measuring the spatial frequency and orientation tuning of brightness perception. In addition, the effect of textures on the spread of brightness and the effect of phase of the inducing stimulus on brightness were measured. The novel findings of the thesis are that (1) a narrow spatial frequency band, independent of stimulus size and complexity, mediates brightness information (2) figure-ground brightness illusions are narrowly tuned for orientation (3) texture borders, without any luminance difference, are able to block the spread of brightness, and (4) edges and even- and odd-symmetric Gabors have a similar antagonistic effect on brightness. The narrow spatial frequency tuning suggests that only a subpopulation of neurons in V1 is involved in brightness perception. The independence of stimulus size and complexity indicates that the narrow tuning reflects hard-wired processing in the visual system. Further, it seems that figure-ground segregation and mechanisms integrating contrast polarities are closely related to the low level mechanisms of brightness perception. In conclusion, the results of the thesis suggest that a subpopulation of neurons in visual cortex selectively integrates information from different contrast polarities to reconstruct surface brightness.

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DEVELOPING A TEXTILE ONTOLOGY FOR THE SEMANTIC WEB AND CONNECTING IT TO MUSEUM CATALOGING DATA The goal of the Semantic Web is to share concept-based information in a versatile way on the Internet. This is achievable using formal data structures called ontologies. The goal of this re-search is to increase the usability of museum cataloging data in information retrieval. The work is interdisciplinary, involving craft science, terminology science, computer science, and museology. In the first part of the dissertation an ontology of concepts of textiles, garments, and accessories is developed for museum cataloging work. The ontology work was done with the help of thesauri, vocabularies, research reports, and standards. The basis of the ontology development was the Museoalan asiasanasto MASA, a thesaurus for museum cataloging work which has been enriched by other vocabularies. Concepts and terms concerning the research object, as well as the material names of textiles, costumes, and accessories, were focused on. The research method was terminological concept analysis complemented by an ontological view of the Semantic Web. The concept structure was based on the hierarchical generic relation. Attention was also paid to other relations between terms and concepts, and between concepts themselves. Altogether 977 concept classes were created. Issues including how to choose and name concepts for the ontology hierarchy and how deep and broad the hierarchy could be are discussed from the viewpoint of the ontology developer and museum cataloger. The second part of the dissertation analyzes why some of the cataloged terms did not match with the developed textile ontology. This problem is significant because it prevents automatic ontological content integration of the cataloged data on the Semantic Web. The research datasets, i.e. the cataloged museum data on textile collections, came from three museums: Espoo City Museum, Lahti City Museum and The National Museum of Finland. The data included 1803 textile, costume, and accessory objects. Unmatched object and textile material names were analyzed. In the case of the object names six categories (475 cases), and of the material names eight categories (423 cases), were found where automatic annotation was not possible. The most common explanation was that the cataloged field was filled with a long sentence comprised of many terms. Sometimes in the compound term, the object name and material, or the name and the way of usage, were combined. As well, numeric values in the material name cataloging field prevented annotation and so did the absence of a corresponding concept in the ontology. Ready-made drop-down lists of materials used in one cataloging system facilitated the annotation. In the case of naming objects and materials, one should use terms in basic form without attributes. The developed textile ontology has been applied in two cultural portals, MuseumFinland and Culturesampo, where one can search for and browse information based on cataloged data using integrated ontologies in an interoperable way. The textile ontology is also part of the national FinnONTO ontology infrastructure. Keywords: annotation, concept, concept analysis, cataloging, museum collection, ontology, Semantic Web, textile collection, textile material

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Tutkimuksen kohderyhmänä oli mediatyöntekijöitä, joiden toimenkuva on viime vuosina muuttunut yhä kuormittavammaksi epäsäännöllisen vuorotyön sekä jatkuvien teknisten, organisatoristen ja taloudellisten tekijöiden ristipaineessa. Väitöskirjatutkimus on osa laajempaa tutkimushanketta, joka suunniteltiin selvittämään epäsäännöllisen vuorotyön mahdollisia haittoja. Tutkimusta tukivat taloudellisesti Työsuojelurahasto ja Suomen Hammaslääkäriseura Apollonia sekä resurssipanostuksin Hammaslääketieteen laitos (HY), Työterveyslaitos ja Yleisradio Oy. Bruksismi on tahdosta riippumatonta hampaiden narskuttelua tai yhteenpuristamista. Hampaiden narskuttelu on rytmistä jaksoittain toistuvaa puremalihasten toimintaa, joka esiintyy nukkuessa -tavallisimmin kevyen unen ja havahtumisjaksojen yhteydessä. Valveilla ollessa bruksismi on terveillä ihmisillä lähinnä hampaiden yhteenpuristamista. Yleisen käsityksen mukaan toistuvaa unibruksismia esiintyy noin 10 %:lla ja valveilla tapahtuvaa hampaiden yhteenpuristamista noin 20 %:lla. Aiemmin bruksismi kuului kansainvälisen unihäiriöluokituksen (ICSD 1997) mukaan unen erityishäiriöihin, mutta tuorein luokitus (ICSD 2005) listaa sen unen liikehäiriöihin. Väitöstutkimuksen yleisenä tavoitteena oli kartoittaa koetun bruksismin ja uni- valvehäiriöiden yhteyttä. Tutkimus oli poikittainen vertailututkimus epäsäännöllistä vuorotyötä ja säännöllisiä päivävuoroja tekevien välillä. Mielenkiinto kohdistui myös bruksismin ja kasvojen alueen kivun mahdolliseen yhteyteen. Lisäksi tutkimuksessa selvitettiin joidenkin tunnetusti unen laatua huonontavien psykososiaalisten, neurologisten ja fysiologisten tekijöiden yhteyttä koettuun bruksismiin. Tutkimuksen kohderyhmän muodosti 750 Yleisradion epäsäännöllistä vuorotyötä tekevää työntekijää. Vertailuryhmänä käytettiin samansuuruista satunnaistetusti valittua kaltaistettua Yleisradion työntekijäjoukkoa, joka tekee samankaltaista työtä, mutta säännöllisenä päivätyönä. Kohderyhmälle lähetettiin kyselylomakkeet, jotka kartoittivat koetun bruksismin lisäksi mm. tutkittavien taustatiedot, yleisen terveydentilan, yleisiä koettuja stressioireita ja tuntemuksia, kipuoireita, sekä unen laatua. Lisäksi esitettiin jaksamista ja työympäristöä koskevia kysymyksiä. Kyselyyn vastasi kaikkiaan 874 henkilöä. Kokonaisvastausprosentti oli 58,3 % (53,7 % miehiä). Epäsäännöllistä vuorotyötä tekevien vastausprosentti oli 82,3 % ja säännöllistä päivätyötä tekevien ryhmässä 34,3 %. Työtehtävät sisälsivät ohjelmien toimitus- ja tuottamistyötä, teknistä tuotanto- ja tukityötä, sekä esimies- ja hallintotyötä. Miesten keski-ikä vuorotyöryhmässä oli 45,0 (± 10,6) vuotta ja naisten keski-ikä 42,6 (± 10,7) vuotta, vastaavat luvut päivätyötä tekeville olivat 47,4 (± 9,7) ja 45,5 (± 10,1) vuotta. Vuorotyötä tekevistä oli miehiä 56,6 %, päivätyöryhmässä miehien osuus oli 46,7 %. Usein koettua bruksismia havaittiin koko tutkimusjoukossa 10,6 %:lla. Bruksismin esiintyvyydessä ei ollut merkitsevää eroa epäsäännöllistä vuorotyötä ja päivätyötä tekevien välillä. Kun bruksismia ja stressiä arvioitiin suhteessa tyytyväisyyteen nykyiseen työaikamuotoon, molemmat olivat merkitsevästi vallitsevimpia niillä, jotka halusivat vaihtaa nykyistä työaikamuotoaan. Epäsäännöllistä vuorotyötä tekevät lisäksi ilmoittivat kokevansa enemmän stressiä kuin päivätyötä tekevät sekä olivat tyytymättömämpiä työaikamuotoonsa. Tutkittavista henkilöistä katkonaista unta esiintyi 43,6 %:lla sekä 36,2 % koki unensa virkistämättömäksi. Kasvokipua esiintyi 19,6 %:lla. Usein toistuva bruksaus sekä tyytymättömyys työaikamuotoon olivat erittäin merkitsevästi yhteydessä unihäiriöiden sekä riittämättömän unen oireiden kanssa. Bruksismi ja katkonainen uni osoittautuivat myös kasvokivun taustatekijöiksi. Tutkimus osoitti, että koetulla bruksismilla oli merkitsevä yhteys unihäiriöihin, kasvokipuun, koettuun stressiin ja ahdistuneisuuteen, nuorempaan ikään, runsaampiin hammaslääkäri- ja lääkärikäynteihin sekä siihen että oli tyytymätön työaikamuotoonsa (itse työaikamuoto ei ollut merkitsevä tekijä). Tutkimuksen yhtenä johtopäätöksenä todettiin, että koettu bruksismi voi terveillä työikäisillä henkilöillä olla osa stressaavaa tilannetta ja siihen liittyvää käyttäytymistä. Tämän tiedostaminen terveydenhuollossa voisi olla hyödyllistä.

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Drug Analysis without Primary Reference Standards: Application of LC-TOFMS and LC-CLND to Biofluids and Seized Material Primary reference standards for new drugs, metabolites, designer drugs or rare substances may not be obtainable within a reasonable period of time or their availability may also be hindered by extensive administrative requirements. Standards are usually costly and may have a limited shelf life. Finally, many compounds are not available commercially and sometimes not at all. A new approach within forensic and clinical drug analysis involves substance identification based on accurate mass measurement by liquid chromatography coupled with time-of-flight mass spectrometry (LC-TOFMS) and quantification by LC coupled with chemiluminescence nitrogen detection (LC-CLND) possessing equimolar response to nitrogen. Formula-based identification relies on the fact that the accurate mass of an ion from a chemical compound corresponds to the elemental composition of that compound. Single-calibrant nitrogen based quantification is feasible with a nitrogen-specific detector since approximately 90% of drugs contain nitrogen. A method was developed for toxicological drug screening in 1 ml urine samples by LC-TOFMS. A large target database of exact monoisotopic masses was constructed, representing the elemental formulae of reference drugs and their metabolites. Identification was based on matching the sample component s measured parameters with those in the database, including accurate mass and retention time, if available. In addition, an algorithm for isotopic pattern match (SigmaFit) was applied. Differences in ion abundance in urine extracts did not affect the mass accuracy or the SigmaFit values. For routine screening practice, a mass tolerance of 10 ppm and a SigmaFit tolerance of 0.03 were established. Seized street drug samples were analysed instantly by LC-TOFMS and LC-CLND, using a dilute and shoot approach. In the quantitative analysis of amphetamine, heroin and cocaine findings, the mean relative difference between the results of LC-CLND and the reference methods was only 11%. In blood specimens, liquid-liquid extraction recoveries for basic lipophilic drugs were first established and the validity of the generic extraction recovery-corrected single-calibrant LC-CLND was then verified with proficiency test samples. The mean accuracy was 24% and 17% for plasma and whole blood samples, respectively, all results falling within the confidence range of the reference concentrations. Further, metabolic ratios for the opioid drug tramadol were determined in a pharmacogenetic study setting. Extraction recovery estimation, based on model compounds with similar physicochemical characteristics, produced clinically feasible results without reference standards.

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We study a Hamiltonian describing a pendulum coupled with several anisochronous oscillators, giving a simple construction of unstable KAM tori and their stable and unstable manifolds for analytic perturbations. When the coupling takes place through an even trigonometric polynomial in the angle variables, we extend analytically the solutions of the equations of motion, order by order in the perturbation parameter, to a large neighbourhood of the real line representing time. Subsequently, we devise an asymptotic expansion for the splitting (matrix) associated with a homoclinic point. This expansion consists of contributions that are manifestly exponentially small in the limit of vanishing gravity, by a shift-of-countour argument. Hence, we infer a similar upper bound for the splitting itself. In particular, the derivation of the result does not call for a tree expansion with explicit cancellation mechanisms.

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Tools known as maximal functions are frequently used in harmonic analysis when studying local behaviour of functions. Typically they measure the suprema of local averages of non-negative functions. It is essential that the size (more precisely, the L^p-norm) of the maximal function is comparable to the size of the original function. When dealing with families of operators between Banach spaces we are often forced to replace the uniform bound with the larger R-bound. Hence such a replacement is also needed in the maximal function for functions taking values in spaces of operators. More specifically, the suprema of norms of local averages (i.e. their uniform bound in the operator norm) has to be replaced by their R-bound. This procedure gives us the Rademacher maximal function, which was introduced by Hytönen, McIntosh and Portal in order to prove a certain vector-valued Carleson's embedding theorem. They noticed that the sizes of an operator-valued function and its Rademacher maximal function are comparable for many common range spaces, but not for all. Certain requirements on the type and cotype of the spaces involved are necessary for this comparability, henceforth referred to as the “RMF-property”. It was shown, that other objects and parameters appearing in the definition, such as the domain of functions and the exponent p of the norm, make no difference to this. After a short introduction to randomized norms and geometry in Banach spaces we study the Rademacher maximal function on Euclidean spaces. The requirements on the type and cotype are considered, providing examples of spaces without RMF. L^p-spaces are shown to have RMF not only for p greater or equal to 2 (when it is trivial) but also for 1 < p < 2. A dyadic version of Carleson's embedding theorem is proven for scalar- and operator-valued functions. As the analysis with dyadic cubes can be generalized to filtrations on sigma-finite measure spaces, we consider the Rademacher maximal function in this case as well. It turns out that the RMF-property is independent of the filtration and the underlying measure space and that it is enough to consider very simple ones known as Haar filtrations. Scalar- and operator-valued analogues of Carleson's embedding theorem are also provided. With the RMF-property proven independent of the underlying measure space, we can use probabilistic notions and formulate it for martingales. Following a similar result for UMD-spaces, a weak type inequality is shown to be (necessary and) sufficient for the RMF-property. The RMF-property is also studied using concave functions giving yet another proof of its independence from various parameters.

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We investigate methods for recommending multimedia items suitable for an online multimedia sharing community and introduce a novel algorithm called UserRank for ranking multimedia items based on link analysis. We also take the initiative of applying EigenRumor from the domain of blogosphere to multimedia. Furthermore, we present a strategy for making personalized recommendation that combines UserRank with collaborative filtering. We evaluate our method with an informal user study and show that results obtained are promising.

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Refractive errors, especially myopia, seem to increase worldwide. Concurrently, the number of surgical refractive corrections has increased rapidly, with several million procedures performed annually. However, excimer laser surgery was introduced after a limited number of studies done with animals and to date there still are only few long-term follow-up studies of the results. The present thesis aims to evaluate the safety and functional outcome of, as well as to quantify the cellular changes and remodelling in the human cornea after, photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK). These procedures are the two most common laser surgical refractive methods. In Study I, myopic ophthalmic residents at Helsinki University Eye Hospital underwent a refractive correction by PRK. Five patients were followed up for 6 months to assess their subjective experience in hospital work and their performance in car driving simulator and in other visuomotor functions. Corneal morphological changes were assessed by in vivo confocal microscopy (ivCM). Study II comprised 14 patients who had undergone a PRK operation in 1993-1994. Visual acuity was examined and ivCM examinations performed 5 years postoperatively. In Study III 15 patients received LASIK refractive correction for moderate to high myopia (-6 - -12 D). Their corneal recovery was followed by ivCM for 2 years. Diffuse lamellar keratitis (DLK) is a common but variable complication of LASIK. Yet, its aetiology remains unknown. In Study IV we examined six patients who had developed DLK as a consequence of formation of an intraoperative or post-LASIK epithelial defect, to assess the corneal and conjunctival inflammatory reaction. In the whole series, the mean refractive correction was -6.46 diopters. The best spectacle corrected visual acuity (BSCVA) improved in 30 % of patients, whereas in four patients BSCVA decreased slightly. The mean achieved refraction was 0.35 D undercorrected. After PRK, the stromal scar formation was highest at 2 to 3 months postoperatively and subsequently decreased. At 5 years increased reflectivity in the subepithelial stroma was observed in all patients. Interestingly, no Bowman s layer was detected in any patient. Subbasal nerve fiber bundle(snfb) regeneration could be observed already at 2 months in 2 patients after PRK. After 5 years, all corneas presented with snfb, the density of which, however, was still lower than in control corneas. LASIK induced a hypocellular area on both sides of the flap interface. A decrease of the most anterior keratocyte density was also observed. In the corneas that developed DLK, inflammatory cell-type objects were present in the flap interface in half of the patients. The other patients presented only with keratocyte activation and highly reflective extracellular matrix. These changes resolved completely with medication and time. Snfb regeneration was first detected at one month post-LASIK, but still after two years the density of snfb, however, was only 64 % of the preoperative values. The performance of ophthalmological examinations and microsurgery without spectacles was easier postoperatively, which was appreciated by the residents. Both PRK and LASIK showed moderate to good accuracy and high safety. In terms of visual perception and subjective evaluation, few patients stated any complaints in the whole series of studies. Instead, the majority of patients experienced a marked improvement in everyday life and work performance. PRK and LASIK have shown similar results, with good long term morphological healing. It seems evident that, even without the benefit of over-20-year follow-up results, these procedures are sufficiently safe and accurate for refractive corrections and corneal reshaping.

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The thesis explores the discourse of two global news agencies, the Associated Press (AP) and Reuters, which together with the French AFP are generally regarded as the world s leading news distributors. A glance at the guidelines given by AP and Reuters to their journalists shows that these two news agencies make a lot of effort to strive for objectivity the well-known journalistic ideal, which, however, is an almost indefinable concept. In journalism textbooks definitions of objectivity often contain various components: detachment, nonpartisanship, facticity, balance, etc. AP and Reuters, too, in their guidelines, present several other ideals besides objectivity , viz., reliability, accuracy, balance, freedom from bias, precise sourcing, reporting the truth, and so on. Other central concepts connected to objectivity are neutrality and impartiality. However, objectivity is, undoubtedly, the term that is most often mentioned when the ethics of journalism is discussed, acting as a kind of umbrella term for several related journalistic ideals. It can even encompass the other concept that is relevant for this study, that of factuality. These two intertwined concepts are extremely complex; paradoxically, it is easier to show evidence of the lack of objectivity or factuality than of their existence. I argue that when journalists conform to the deep-rooted conventions of objective news reporting, facts may be blurred, and the language becomes vague and ambiguous. As global distributors of news, AP and Reuters have had an influential role in creating and reinforcing conventions of (at least English-language) news writing. These conventions can be seen to work at various levels of news reporting: the ideological (e.g., defining what is regarded as newsworthy, or who is responsible), structural (e.g., the well-known inverted pyramid model), and stylistic (e.g., presupposing that in hard news reports, the journalist s voice should be backgrounded). On the basis of my case studies, I have found four central conventions to be worthy of closer examination: the conventional structure of news reports, the importance of newsworthiness, the tactics of impersonalisation which tends to blur news actors responsibility, and the routines of presenting emotions. My linguistic analyses draw mainly on M.A.K. Halliday s Systemic Functional Grammar, on notions of transitivity, ergativity, nominalisation and grammatical metaphor. The Appraisal framework, too, has provided useful tools for my analyses. The thesis includes six case studies dealing with the following topics: metaphors in political reporting, terrorism discourse, terrorism fears, emotions more generally, unnamed sources as rhetorical constructs, and responsibility in the convention of attribution.