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The max-bisection problem is to find a partition of the vertices of a graph into two equal size subsets that maximizes the number of edges with endpoints in both subsets. We obtain new improved approximation ratios for the max-bisection problem on the low degree k-regular graphs for 3 less than or equal to k less than or equal to 8, by deriving some improved transformations from a maximum cut into
The weighted oscillator strengths (gf) and the lifetimes presented in this work were carried out in a multiconfiguration Hartree-Fock relativistic approach. In this calculation, the electrostatic parameters were optimized by a least-squares procedure, in order to improve the adjustment to experimental energy levels. This method produces gf-values that are in better agreement with intensity observa
MRI and CT are modalities appropriate for liver imaging. To obtain higher sensitivity in diagnoses of focal lesions in the liver, contrast media (CM) are used. Non-specific extracellular CM are not optimal as they rapidly diffuse into both normal tissue and tumorous tissue. By two different mechanisms, the hepatobiliary route and targeting to the reticuloendothelial system, agents may accumulate i
Aim: To study the influence of specific factors and events during pregnancy and the perinatal period on the risk of children developing inflammatory bowel disease. Methods: Population-based national register study. Linkage between the Swedish Medical Birth Register and the Swedish Hospital Discharge Register during the period 1987 to 2000 identified 455 singleton infants who later developed inflam
The budding yeast species Saccharomyces castellii has provided important new insights into molecular evolution when incorporated in comparative genomics studies and studies of mitochondrial inheritage. Although it shows some diversity in the specific molecular details, several analyses have shown that it contains many genetic pathways similar to those of S. cerevisiae. Here we have investigated th
Conjugate addition of Meldrum's acid to 2-cyclohexenone followed by direct cyclization in PPA/acetic acid constitutes a shorter, more reproducible and higher yielding route to bicyclo[2.2.2]octane-2,6-dione than previous methods. The crude dione could be used as substrate for the baker's yeast reduction to (IR, 4S, 6S)-bicyclo[2.2.2]octane-6-ol-2-one.
A method has been developed that automatically constructs a crystallographic refinement force field (topology and parameter files) for any molecule from a theoretical frequency calculation. The approach has been tested on five proteins containing metal sites or non-standard inhibitors or coenzymes and it is shown that the structures are improved in various aspects.
Configuration management (CM) includes synchronizing and supporting developers in their common development and maintenance of a system. In order to utilize personnel regardless of their geographical location, groups of developers are now working all over the world on the development of common systems, a situation called distributed development. From different locations they may need to concurrentl
Purpose: To our knowledge we report the first long-term use of desmopressin for nocturia. Patients previously responding to desmopressin in short-term studies were enrolled in this long-term open label study. Materials and Methods: Patients received treatment for 10 or 12 months with the optimal desmopressin dose (0.1, 0.2 or 0.4 mg orally at bedtime). Patients were followed a further month withou
Between 1980 and 1983, 10 patients received high performance silicone rubber condylar implants for the treatment of isolated degenerative changes of the scaphotrapezial joint. Early clinical and radiographic results (at a mean of 15 months) were excellent. Late follow up of these 10 together with a further 11 patients, however, showed migration of the implant and radiological signs of silicone par
Popular Abstract in Swedish I denna avhandling studerar jag tvådimensionella geometriska optimeringsproblem. Gemensamt för många praktiskt och teoretiskt intressanta problemställningar inom området är att det är mycket svårt att ta fram optimala lösningar. Det tar helt enkelt alltför lång tid att undersöka alla möjligheter för probleminstanser med stora mängder indata då beräkningstiden växer expoIn this thesis I study two-dimensional geometric optimization problems for which it is difficult to find efficient, exact, deterministic algorithms. All known solutions to these problems require time that is exponential in the total size of the input. The work done in this thesis is a contribution to the research directed at attacking and coping with such NP hard problems in computational geometry
In this paper, a new frequency offset correction approach for OFDM is proposed to track a wider range of offsets than conventional proposals, without devoting specific pilot symbols for synchronization. This can be attained since, in coherent OFDM, channel estimation is usually performed employing pilot-symbol assisted-modulation (PSAM), based on inserting known symbols in the time-frequency grid.
In time-selected migration birds adapt their fuel deposition and flight behaviour to maximise sustained migration speed. What are the expectations for the final part of spring migration when the transition to breeding takes place and the criterion of a maximum total migration speed is no longer relevant? Two possible strategies representing different ends of the capital – income spectrum are evalu
Shock waves are discontinuous solutions to quasi-linear partial differential equations and can be studied through a singular perturbation known as the vanishing viscosity technique. The vanishing viscosity method is a means of smoothing the shock, which we use to study the case of electromagnetic waves in bianisotropic materials. We derive the conditions arising from this smoothing procedure for a
Biomass gasification for energy or hydrogen production is a field in continuous evolution, due to the fact that biomass is a renewable and CO2 neutral source. The ability to produce biomass-derived vehicle fuel on a large scale will help to reduce greenhouse gas and pollution, increase the security of European energy supplies, and enhance the use of renewable energy. The Varnamo, Biomass Gassifica
Techniques for estimation of element levels directly in humans (noninvasive in vivo) or in samples (in vitro) from humans are reviewed. Toxic, nonessential, trace elements may cause temporary or permanent damage to various organs and tissues in humans. There is thus a need to control the concentrations. Knowledge of the relations between toxic effects and element concentration may be extracted fro
This paper studies the design of signaling waveforms for time-hopping impulse radio (TH-IR) with limits on the power spectral density. Such restrictions are imposed by the spectral mask prescribed by frequency regulators for ultra-wideband (UWB) signals. The "conventional" TH-IR system with pulse-position modulation and time-hopping multiple access gives rise to spectral lines that either violate
Målet med arbetet som presenteras i denna licentiatuppsats är att genomföra en analys av problemkomplexet inomhusluft och att med ledning av denna analys anvisa vägar att minska inneluftproblem i framtida byggande. Utifrån detta har tre delsyften formulerats: (1) Analysera existerande inneluftproblem och i samband därmed beskriva vilka faktorer i inomhusluften som medför problem, vilka faktorer so
