Journal Staff

Imaging is an invaluable tool in many research areas and other advanced domains such as health care. When developing any system dealing with images, image quality issues are insurmountable. This report describes digital image quality from many viewpoints, from retinal receptor characteristics to perceptual compression algorithms. Special focus is given to perceptual image quality measures

Sovereignty Over Certain Frontier Land: Belgium/The Netherlands

I samhället uppmärksammas tekniken för sin ökande komplexitet och systemiska karaktär. l vilken mån avspeglar sig detta i skolans teknikämne? Denna avhandling berör undervisning om tekniska system i ett skolperspektiv, med det huvudsakliga syftet att undersöka hur undervisning om tekniska system tas upp till behandling i skolan. Den övergripande frågeställningen är: Hur har skolan hanterat den  didaktiska uppgiften att utveckla ett undervimingsområde om tekniska system? Avhandlingen är en monografi som bygger på delstudier av tre arenor  med relevans för skolan. De tre arenorna omfattar huvudsakligen nationella styrdokument, läromedel respektive lärares arbete. Resultaten pekar bland annat på att tekniska system successivt  förstärkts som undervisningsinnehåll i styrdokument och läromedel sedan slutet på 1970-talet. Denna förändring har skett parallellt med att teknikämnets beskrivning förändrats i grundskolan. I öäverenstämmelse med modern teknikfilosofi har teknik i skolsammanhang i allt högre grad kommit att framställas som en egen kunskapskultur och inte som en del av naturvetenskaperna. Detta har varit förutsättningar för att tekniska system har kunnat etableras som innehåll. Diskursen talet om tekniska rys/em har dock skiftat i karaktär över tiden. Gemensamt för de tre arenorna är att två hegemoniska diskurser har hämmat introduktionen av tekniska system. För det första teknikundervisningens egen fascination för enkla artefakter och, för det andra, en dominant naturvetenskaplig diskurs. Härmed fokuseras undervisningen på systemens komponenter, snarare än mot systemnivån. Så tenderar t.ex. undervisning om energisystem att handla om energiomvandlingar eller kemiska reaktioner, istället för systemens uppbyggnad, funktioner, eller dess relationer till människor och samhälle. Avhandlingen visar även att tekniska system framställs som faktiskt existerande och inte som mentala konstruktioner vars gränser måste bestämmas. Produktions- och transportsystem ges framträdande positioner i teknikinnehållet. Tekniska system belyses snarare som något som påverkar omgivningen, än att de är möjliga att påverka. Överlag finns en brist på systembegrepp. Dock har styr- och reglerteknik nått en viss position. 1 avhandlingen visas även hur människans roll relativt systemen tas upp och, i samband med detta, hur ett etiskt och politiskt tema vuxit fram inom arenornas teknikdiskurs. Temat har medborgerliga förtecken och tar sina motiv från en strävan mot en hållbar utveckling. Utifrån en teknikhistorisk emfas används argument för att eleverna bör studera tekniska systems framväxt och förändring.In our society technology is becorning increasingly complex. Technological systems are now part of our evetyday lives. To what extent is this reflected in the Technology subject? This dissertation concerns education and has the aim of investigating how technological systems are treated in the Swedish school system. The overarching question is: How has the Swedish compulsory school dealt with the pedagogical challenge of det'eloping miject content about technological systems? To answer this question, the discourse of school talk on technological systems across three different school arenas has been the focus of the study so that pedagogical challenges and historicallayers relating to the discourse can be outlined. The three school arenas are the formulation, mediation, and realisation arena. They mainly encompass national curriculae, text books and teachers work, respectively, from 1980 to 2009. On the realisation arena an interactive method has been used where the researcher collaborated with a team of teachers in a lower secondary school for two years. The results are presented in two ways. First, a set of offered companion meamngs found in the expressions on the arenas are presented. The compamon meamngs emanate from three kinds of rules regolating the discourse: educational focus, system languages and curriculum emphases. Second, each arena is discussed in detail. These discussions were arrived at by feeding the categories of compamon meamngs back into the analysis process as a tool to clarify themes, orders of discourse and changes over time. On the arenas subject content relating to technological systems has successive ly strengthened its position and can be found on several curricular levels. This shift is made possible by new descriptions of technology as a distinct field of knowledge, thus affecting the view of the school subject Technology. In a Swedish context this meant dissociation from the natural sciences. Two hegemonic discourses that make the pedagogical challenge to introduce technological systems more difficult have also been found: the hegemony of the artefact and the hegemony of science. The first relates to the subject's internal interest for small products and components. The second is based on a scientific precedence where Technology is used as an arena for the illustration of scientific laws and rules. Both hegemonies have the effect of directing the educational focus away from the systernic issues around the technology at hand. The search for answers is turned inwards and downwards in the systemic hierarchy. On the other hand, production systems and controi technology have established a position in the discourse. An emerging political and ethical theme concerned with the relation between citizenship, sustainable development and technology has forwarded a systems approach.Avhandlingen finns även som talbok, TPB-nr: CA01926.</p

Homecoming

A young Navy SK3 experiences his last mission before coming home to a country with very different opinions about his service. Articles, stories, and other compositions in this archive were written by participants in the Mighty Pen Project. The program, developed by author David L. Robbins, and in partnership with Virginia Commonwealth University and the Virginia War Memorial in Richmond, Virginia, offers veterans and their family members a customized twelve-week writing class, free of charge. The program encourages, supports, and assists participants in sharing their stories and experiences of military experience so both writer and audience may benefit

On trade-offs between timber and biodiversity

For a long time the primary aim of forestry in Sweden has been the production of timber, but in recent decades other functions, such as biodiversity, have been increasingly recognised by society. Sweden has ambitious goals for forest management, aimed at serving public interests, providing valuable timber yields and preserving biodiversity. Achieving the level of various goods that forests shall provide, under such goals, is thus rather complex. This thesis focuses on trade-offs between production of timber and the maintenance of biodiversity in forests, and the effects of information on benefits, costs and biological traits. In Paper I the benefit of forest land protection was estimated based on a nation wide contingent valuation survey. Paper II examined and compared, through survey data, the attitudes among private forest owners and forest officers. Papers III and IV used data from a field inventory in old growth forests (>110 years of age) of Norway spruce (Picea abies [L.] Karst.) in the county of Gävleborg, Sweden. In Paper III the relative importance of information about costs and biological traits in reserve selection was examined. In Paper IV the cost-efficiency of different strategies for setting aside forests, using different biodiversity targets, were analysed. The thesis revealed a positive willingness to pay for forest land protection among Swedish citizens, and also a positive attitude among private forest owners to biodiversity as well as timber production. The views of forest owners and forest officers did not always coincide. Moreover, the relative importance of including data on costs and conservation benefits depended on how the conservation goal of the reserve network was formulated. There was also a difference in cost-effectiveness between different nature conservation strategies and biodiversity targets. The results emphasise the importance of achieving cost-effective solutions in biodiversity conservation through the proper use of information about biological traits and costs, as well as considering values and attitudes held by different interest groups in society

The Nature of Generic Cosmological Singularities

The existence of a singularity by definition implies a preferred scale--the affine parameter distance from/to the singularity of a causal geodesic that is used to define it. However, this variable scale is also captured by the expansion along the geodesic, and this can be used to obtain a regularized state space picture by means of a conformal transformation that factors out the expansion. This leads to the conformal `Hubble-normalized' orthonormal frame approach which allows one to translate methods and results concerning spatially homogeneous models into the generic inhomogeneous context, which in turn enables one to derive the dynamical nature of generic cosmological singularities. Here we describe this approach and outline the derivation of the `cosmological billiard attractor,' which describes the generic dynamical asymptotic behavior towards a generic spacelike singularity. We also compare the `dynamical systems picture' resulting from this approach with other work on generic spacelike singularities: the metric approach of Belinskii, Lifschitz, and Khalatnikov, and the recent Iwasawa based Hamiltonian method used by Damour, Henneaux, and Nicolai; in particular we show that the cosmological billiards obtained by the latter and the cosmological billiard attractor form complementary `dual' descriptions of the generic asymptotic dynamics of generic spacelike singularities.Comment: 14 pages, six figures; invited talk at the 11th Marcel Grossmann Meeting on Recent Developments in General Relativity, Berlin, Germany, 23-29 July 200

The X-ray and radio emission from SN 2002ap: The importance of Compton scattering

The radio and X-ray observations of the Type Ic supernova SN 2002ap are modeled. We find that inverse Compton cooling by photospheric photons explains the observed steep radio spectrum, and also the X-ray flux observed by XMM. Thermal emission from the shock is insufficient to explain the X-ray flux. The radio emitting region expands with a velocity of, roughly, 70,000 km/s. From the ratio of X-ray to radio emission we find that the energy densities of magnetic fields and relativistic electrons are close to equipartion.Comment: 15 pages, 2 figures, ApJ accepte

Photon propagation in a stationary warp drive space-time

We simplify the warp drive space-time so that it becomes stationary and the distorsion becomes one-dimensional and static. We use this simplified warp drive space-time as a background for a photon field. We shall especially use the Drummond\&Hathrell action in order to investigate the velocity effects on photons in this background. Finally, we discuss the limitations of this model.Comment: 10 pages Latex, Revised, major changes -no tunneling model