32 resultados para structured light


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By detecting leading protons produced in the Central Exclusive Diffractive process, p+p → p+X+p, one can measure the missing mass, and scan for possible new particle states such as the Higgs boson. This process augments - in a model independent way - the standard methods for new particle searches at the Large Hadron Collider (LHC) and will allow detailed analyses of the produced central system, such as the spin-parity properties of the Higgs boson. The exclusive central diffractive process makes possible precision studies of gluons at the LHC and complements the physics scenarios foreseen at the next e+e− linear collider. This thesis first presents the conclusions of the first systematic analysis of the expected precision measurement of the leading proton momentum and the accuracy of the reconstructed missing mass. In this initial analysis, the scattered protons are tracked along the LHC beam line and the uncertainties expected in beam transport and detection of the scattered leading protons are accounted for. The main focus of the thesis is in developing the necessary radiation hard precision detector technology for coping with the extremely demanding experimental environment of the LHC. This will be achieved by using a 3D silicon detector design, which in addition to the radiation hardness of up to 5×10^15 neutrons/cm2, offers properties such as a high signal-to- noise ratio, fast signal response to radiation and sensitivity close to the very edge of the detector. This work reports on the development of a novel semi-3D detector design that simplifies the 3D fabrication process, but conserves the necessary properties of the 3D detector design required in the LHC and in other imaging applications.

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This thesis reports investigations into the paper wetting process and its effects on the surface roughness and the out-of-plane (ZD) stiffness of machine-made paper. The aim of this work was to test the feasibility of employing air-borne ultrasound methods to determine surface roughness (by reflection) and ZD stiffness (by through transmission) of paper during penetration of distilled water, isopropanol and their mixtures. Air-borne ultrasound provides a non-contacting way to evaluate sample structure and mechanics during the liquid penetration event. Contrary to liquid immersion techniques, an air-borne measurement allows studying partial wetting of paper. In addition, two optical methods were developed to reveal the liquid location in paper during wetting. The laser light through transmission method was developed to monitor the liquid location in partially wetted paper. The white light reflection method was primarily used to monitor the penetration of the liquid front in the thickness direction. In the latter experiment the paper was fully wetted. The main results of the thesis were: 1) Liquid penetration induced surface roughening was quantified by monitoring the ultrasound reflection from the paper surface. 2) Liquid penetration induced stiffness alteration in the ZD of paper could be followed by measuring the change in the ultrasound ZD resonance in paper. 3) Through transmitted light revealed the liquid location in the partially wetted paper. 4) Liquid movement in the ZD of the paper could be observed by light reflection. The results imply that the presented ultrasonic means can without contact measure the alteration of paper roughness and stiffness during liquid transport. These methods can help avoiding over engineering the paper which reduces raw material and energy consumption in paper manufacturing. The presented optical means can estimate paper specific wetting properties, such as liquid penetration speed, transport mechanisms and liquid location within the paper structure. In process monitoring, these methods allow process tuning and manufacturing of paper with engineered liquid transport characteristics. With such knowledge the paper behaviour during printing can be predicted. These findings provide new methods for paper printing, surface sizing, and paper coating research.

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The increased accuracy in the cosmological observations, especially in the measurements of the comic microwave background, allow us to study the primordial perturbations in grater detail. In this thesis, we allow the possibility for a correlated isocurvature perturbations alongside the usual adiabatic perturbations. Thus far the simplest six parameter \Lambda CDM model has been able to accommodate all the observational data rather well. However, we find that the 3-year WMAP data and the 2006 Boomerang data favour a nonzero nonadiabatic contribution to the CMB angular power sprctrum. This is primordial isocurvature perturbation that is positively correlated with the primordial curvature perturbation. Compared with the adiabatic \Lambda CMD model we have four additional parameters describing the increased complexity if the primordial perturbations. Our best-fit model has a 4% nonadiabatic contribution to the CMB temperature variance and the fit is improved by \Delta\chi^2 = 9.7. We can attribute this preference for isocurvature to a feature in the peak structure of the angular power spectrum, namely, the widths of the second and third acoustic peak. Along the way, we have improved our analysis methods by identifying some issues with the parametrisation of the primordial perturbation spectra and suggesting ways to handle these. Due to the improvements, the convergence of our Markov chains is improved. The change of parametrisation has an effect on the MCMC analysis because of the change in priors. We have checked our results against this and find only marginal differences between our parametrisation.

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Several excited states of Ds and Bs mesons have been discovered in the last six years: BaBar, Cleo and Belle discovered the very narrow states D(s0)*(2317)+- and D(s1)(2460)+- in 2003, and CDF and DO Collaborations reported the observation of two narrow Bs resonances, B(s1)(5830)0 and B*(s2)(5840)0 in 2007. To keep up with experiment, meson excited states should be studied from the theoretical aspect as well. The theory that describes the interaction between quarks and gluons is quantum chromodynamics (QCD). In this thesis the properties of the meson states are studied using the discretized version of the theory - lattice QCD. This allows us to perform QCD calculations from first principles, and "measure" not just energies but also the radial distributions of the states on the lattice. This gives valuable theoretical information on the excited states, as we can extract the energy spectrum of a static-light meson up to D wave states (states with orbital angular momentum L=2). We are thus able to predict where some of the excited meson states should lie. We also pay special attention to the order of the states, to detect possible inverted spin multiplets in the meson spectrum, as predicted by H. Schnitzer in 1978. This inversion is connected to the confining potential of the strong interaction. The lattice simulations can also help us understand the strong interaction better, as the lattice data can be treated as "experimental" data and used in testing potential models. In this thesis an attempt is made to explain the energies and radial distributions in terms of a potential model based on a one-body Dirac equation. The aim is to get more information about the nature of the confining potential, as well as to test how well the one-gluon exchange potential explains the short range part of the interaction.

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Solar flares were first observed by plain eye in white light by William Carrington in England in 1859. Since then these eruptions in the solar corona have intrigued scientists. It is known that flares influence the space weather experienced by the planets in a multitude of ways, for example by causing aurora borealis. Understanding flares is at the epicentre of human survival in space, as astronauts cannot survive the highly energetic particles associated with large flares in high doses without contracting serious radiation disease symptoms, unless they shield themselves effectively during space missions. Flares may be at the epicentre of man s survival in the past as well: it has been suggested that giant flares might have played a role in exterminating many of the large species on Earth, including dinosaurs. Having said that prebiotic synthesis studies have shown lightning to be a decisive requirement for amino acid synthesis on the primordial Earth. Increased lightning activity could be attributed to space weather, and flares. This thesis studies flares in two ways: in the spectral and the spatial domain. We have extracted solar spectra using three different instruments, namely GOES (Geostationary Operational Environmental Satellite), RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) and XSM (X-ray Solar Monitor) for the same flares. The GOES spectra are low resolution obtained with a gas proportional counter, the RHESSI spectra are higher resolution obtained with Germanium detectors and the XSM spectra are very high resolution observed with a silicon detector. It turns out that the detector technology and response influence the spectra we see substantially, and are important to understanding what conclusions to draw from the data. With imaging data, there was not such a luxury of choice available. We used RHESSI imaging data to observe the spatial size of solar flares. In the present work the focus was primarily on current solar flares. However, we did make use of our improved understanding of solar flares to observe young suns in NGC 2547. The same techniques used with solar monitors were applied with XMM-Newton, a stellar X-ray monitor, and coupled with ground based Halpha observations these techniques yielded estimates for flare parameters in young suns. The material in this thesis is therefore structured from technology to application, covering the full processing path from raw data and detector responses to concrete physical parameter results, such as the first measurement of the length of plasma flare loops in young suns.

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Bangladesh, often better known to the outside world as a country of natural calamities, is one of the most densely populated countries in the world. Despite rapid urbanization, more than 75% of the people still live in rural areas. The density of the rural population is also one of the highest in the world. Being a poor and low-income country, its main challenge is to eradicate poverty through increasing equitable income. Since its independence in 1971, Bangladesh has experienced many ups and downs, but over the past three decades, its gross domestic product (GDP) has grown at an impressive rate. Consequently, the country s economy is developing and the country has outperformed many low-income countries in terms of several social indicators. Bangladesh has achieved the Millennium Development Goal (MDG) of eliminating gender disparity in primary and secondary school enrollment. A sharp decline in child and infant mortality rates, increased per capita income, and improved food security have placed Bangladesh on the track to achieving in the near future the status of a middle-income country. All these developments have influenced the consumption pattern of the country. This study explores the consumption scenario of rural Bangladesh, its changing consumption patterns, the relationship between technology and consumption in rural Bangladesh, cultural consumption in rural Bangladesh, and the myriad reasons why consumers nevertheless feel compelled to consume chemically treated foods. Data were collected in two phases in the summers of 2006 and 2008. In 2006, the empirical data were collected from the following three sources: interviews with consumers, producers/sellers, and doctors and pharmacists; observations of sellers/producers; and reviews of articles published in the national English and Bengali (the national language of Bangladesh) daily newspapers. A total of 110 consumers, 25 sellers/producers, 7 doctors, and 7 pharmacists were interviewed and observed. In 2008, data were collected through semi-structured in-depth qualitative interviews, ethnography, and unstructured conversations substantiated by secondary sources and photographs; the total number of persons interviewed was 22. -- Data were also collected on the consumption of food, clothing, housing, education, medical facilities, marriage and dowry, the division of labor, household decision making, different festivals such as Eid (for Muslims), the Bengali New Year, and Durga puja (for Hindus), and leisure. Qualitative methods were applied to the data analysis and were supported by secondary quantitative data. The findings of this study suggest that the consumption patterns of rural Bangladeshis are changing over time along with economic and social development, and that technology has rendered aspects of daily life more convenient. This study identified the perceptions and experiences of rural people regarding technologies in use and explored how culture is associated with consumption. This study identified the reasons behind the use of hazardous chemicals (e.g. calcium carbide, sodium cyclamate, cyanide and formalin, etc.) in foods as well as the extent to which food producers/sellers used such chemicals. In addition, this study assessed consumer perceptions of and attitudes toward these contaminated food items and explored how adulterated foods and food stuffs affect consumer health. This study also showed that consumers were aware that various foods and food stuffs contained hazardous chemicals, and that these adulterated foods and food stuffs were harmful to their health.

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Starting point in the European individualistic copyright ideology is that an individual author creates a work and controls the use of it. However, this paper argues that it is (and has always been) impossible to control the use of works after their publication. This has also been acknowledged by the legislator, who has introduced collective licensing agreements because of this impossibility. Since it is impossible to rigorously control the use of works this writing "Rough Justice or Zero Tolerance - Reassessing the Nature of Copyright in Light of Collective Licensing" examines what reality of copyright is actually about. Finding alternative (and hopefully more "true") ways to understand copyright helps us to create alternative solutions in order to solve possible problems we have as it comes e.g. to use of content in online environment. The paper makes a claim that copyright is actually about defining negotiation points for different stakeholders and that nothing in the copyright reality prevents us from defining e.g. a new negotiation point where representatives of consumers would meet representatives of right holders in order to agree on the terms of use for certain content types in online environment.

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In smaller countries where the key players in construction IT development tend to know each other personally and where public R&D funding is concentrated to a few channels, IT roadmaps and strategies would seem to have a better chance of influencing development than in the bigger industrial countries. In this paper Finland and the RATAS-project is presented as a historical case illustrating such impact. RATAS was initiated as a construction IT roadmap project in 1985, involving many of the key organisations and companies active in construction sector development. Several of the individuals who took an active part in the project have played an important role in later developments both in Finland and on the international scene. The central result of RATAS was the identification of what is nowadays called Building Information Modelling (BIM) technology as the central issue in getting IT into efficient use in the construction sector. BIM, which earlier was referred to as building product modelling, has been a key ingredient in many roadmaps since and the subject of international standardisation efforts such as STEP and IAI/IFCs. The RATAS project can in hindsight be seen as a forerunner with an impact which also transcended national borders.

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Whilst previous research on Human Resource Management (HRM) in subsidiaries of multinational companies (MNCs) has focused extensively on the HRM practices that exist in foreign subsidiaries and the extent to which they resemble MNC home country and/or local host country practices, considerably less attention has been directed at the question of how these practices come to exist. Accordingly, this thesis aims to shed light on the processes that shape HRM practices and capabilities in MNC subsidiaries. The main contribution of the thesis is the focus on how; how HRM practices are integrated in MNC subsidiaries, and how subsidiary HRM capabilities are developed through involvement in social networks. Furthermore, this thesis includes a time aspect which, despite not being purely longitudinal, provides an indication of the ongoing changes in HRM in MNC subsidiaries in China. Data for this study were collected in 2005-2006 through structured face to face interviews with 153 general managers and HR managers in 87 subsidiaries of European MNCs located in China. Five of the six thesis papers build on this questionnaire data and one paper builds on qualitative data collected at the same time. Two papers build on dual data sets, meaning that they in addition to the abovementioned data include quantitative questionnaire data from 1996 and 1999 respectively. The thesis focuses on the following four sub-questions i) To what extent do subsidiary HRM practices resemble parent MNC and host country practices? How has this changed over time and why? ii) How are HRM practices integrated into MNC subsidiaries and why are certain integration mechanisms used? iii) How does involvement in internal and external social networks influence subsidiary HRM capabilities? iv) What factors influence the strategic role of the subsidiary HR department? Regarding the first sub-question the findings indicate that the HRM practices of MNC subsidiaries in China are converging with both local company practices and parent MNC practices. This is interesting in the sense that it suggests that the isomorphic pressures the subsidiary faces from the MNC and from its local host environment are not always in conflict with each other. Concerning the question of how HRM practices are integrated into MNC subsidiaries and why certain integration mechanisms are used, the thesis provides a fine-grained examination of four mechanisms that MNCs use to integrate HRM practices in subsidiaries. The findings suggest that MNCs use a variety of different integration mechanisms as complements rather than as substitutes for each other. Furthermore, it is apparent that different contextual factors in the subsidiary and the subsidiary-headquarters relationship influence why certain mechanisms are or are not used. The most interesting contribution of the thesis in regard to the third question is that it highlights the importance of network involvement for learning about HRM practices in the Chinese context. Networks with other MNCs in China clearly emerged as particularly important contributors to enhanced HRM capabilities. Finally, concerning the fourth sub-question the findings indicate that the role of the HR department in MNC subsidiaries in China had become more strategic between 1999 and 2006.

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Suomessa asuvat somalitaustaiset maahanmuuttajaäidit luopuvat imetyksestä ja ruokkivat vauvojaan äidinmaidonkorvikkeella, vaikka somalikulttuurissa arvostetaan imetystä. Tuen ja tiedon puutetta on arveltu syyksi pulloruokinnan yleisyyteen. Tarkoituksenani on tutkia osallistavia menetelmiä käyttäen, minkälaisia imetykseen liittyviä tietojärjestelmiä somaliäidit pitävät auktoritatiivisina eli arvovaltaisina. Tarkastelen tiedon auktoritatiivisuutta etnografisten esimerkkien valossa hyödyntäen Brigitte Jordanin auktoritatiivisen tiedon käsitettä. Tutkin Jean Pierre Olivier de Sardanin teorian avulla, kuinka paikalliset populaarit tietojärjestelmät kohtaavat tieteellis-teknisen tiedon kehityksen kontekstissa. Tutkin myös, kuinka somaliäitien imetystietojärjestelmät kohtaavat suomalaisen terveydenhoitojärjestelmän edustaman imetystiedon. Osallistavien menetelmien tarkoituksena on saada heikkojen ja sorrettujen yhteisöjen ääni kuuluviin. Tutkimukseni tiedonantajina on seitsemäntoista somalimaahanmuuttajaäitiä ja yksi suomalainen äitiys- ja lastenneuvolan terveydenhoitaja. Käytän tiedonkeruumenetelminä puolistrukturoituja teemahaastatteluja, jonka lisäksi teen osallistuvaa havainnointia ja osallistavia menetelmiä kolmessa ryhmähaastattelutilanteessa. Käytän Rapi Rurad Appraisal (RRA) –menetelmiä, kuten Venn-diagrammia ja pisteytystä. Tutkimukseni tulos on, että somaliäitien imetykseen liittyvä tieto koostuu kolmesta tietojärjestelmästä, joita ovat sukuverkostoista tuleva perinteinen tietotaito, islaminuskon terveystieto sekä suomalaisen terveydenhoitojärjestelmän tieto. Näistä eri tietolähteistä tuleva imetystieto ei ole sisällöltään ristiriidassa. Imetykseen liittyvät vaikeudet ovat käytännön ongelmiin, kuten sukuverkoston hajoamiseen ja suomalaisen terveydenhoitojärjestelmän kanssa kommunikointiin liittyviä.

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The tourism development nexus in southern Africa involves highly topical issues related to tourism planning, power relations, community participation, and natural resources. Namibia offers a particularly interesting context for the study of these issues due to its colonial legacy, vast tourism potential, recently adopted tourism policy and community-based approaches to tourism and natural resource management. This study is an interdisciplinary endeavour to analyse the role of tourism in Namibia s post-apartheid transformation process by focusing on Namibian tourism policy and local tourism enterprises' policy knowledge. Major attention is paid to how the tourism policy's national development objectives are understood and conceptualised by the representatives of different tourism enterprises and the ways in which they relate to the practical needs of the enterprises. Through such local policy knowledge the study explores various opportunities, challenges and constraints related to the promotion of tourism as a development strategy. The study utilises a political economy approach to tourism and development through three current and interrelated discourses which are relevant in the Namibian context. These are tourism, power and inequality, tourism and sustainable development, and tourism and poverty reduction. The qualitative research material was gathered in Namibia in 2006-2007 and 2008. This material consists of 34 semi-structured interviews in 16 tourism enterprises, including private trophy hunting farms and private lodges, small tour operators and community-based tourism enterprises. In addition, the research material consists of observations in the enterprises, and 37 informal and 23 expert interviews. The findings indicate that in the light of local tourism enterprises the tourism policy objectives appear more complex and ambiguous. Furthermore, they involve multiple meanings and interpretations which reflect the socio-economic stratification of the informants and Namibian society, together with the professional stratification of the tourism enterprises and restrictions on the capacity of tourism to address the development objectives. In the light of such findings it is obvious that aspects of power and inequality affect the tourism development nexus in Namibia. The study concludes that, as in the case of other southern African countries, in order to promote sustainable development and reduce poverty, Namibia should not only target tourism growth but pay attention to who benefits from that growth and how. From a political economy point of view, it is important that prevailing structural challenges are addressed equally in the planning of tourism, development and natural resource management. Such approach would help the Namibian majority to enjoy the benefits of increasing tourism in the country.