This thesis introduces and summarizes four papers dealing with the study of double and multiple stars using space astrometry. The introduction gives a brief review of the role of binary observations in various fields of astronomy --- star formation, stellar masses and the mass-luminosity relation, initial mass function, detection of sub-stellar mass companions. The astrometric techniques are also

This paper investigates the implications of an endogenous social work norm for the optimal welfare state program. Assuming that individual productivity is observable, the analysis finds that restrictions on program participation, implying a larger benefit to a smaller group of recipients, may be welfare improving. However, the effect of the norm is indeterminate. The disutility of non-compliance s

Popular Abstract in Swedish En autonom agent kan definieras som ett system som med syfte att utföra uppgifter kan interagera med sin omgivning genom sina egna sensorer och effektorer. En ny arkitektur för autonoma agenter inspirerad av teorin för antecipatoriska system föreslås. Det är en hybrid arkitektur i det avseende att den kombinerar planerande förmåga, som behövs för att lösa långsiktiga prThis thesis has two main themes, autonomous agents and concepts. An autonomous agent is a system capable of interacting with its environment via its own sensors and effectors in order to accomplish some task. Arguments against both purely reactive and purely deliberative agent architectures are presented in favor for hybrid approaches. A novel hybrid approach based on the concept of anticipatory s

This paper describes a low distortion wide band CMOS direct digital RF amplitude modulator, which uses a 10-bit linear interpolation current steering digital to analog converter (DAC) and a Gilbert cell based mixer to generate an amplitude modulated RF signal directly. The linear interpolation increases the attenuation of the DAC's image components. The low pass filter (LPF) is therefore eliminate

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Popular Abstract in Swedish Fysiologisk integrering och morfologisk plasiticitet i stora klonala växter Många av våra vanligaste växter är klonala, dvs de kan producera avkommor utan sexuell befruktning. Hit räknas blåbär och lingon, många av våra vårväxter som tex. vitsippa och flera av våra värsta ogräs, som kvickrot och kirskål. En fördel som klonala växter har är att dotterskott som fortsätteClonal plants show a large variation in physiological integration, i.e. the translocation of resources among ramets within the clone. As resource transport is costly, we hypothesized that plants from poor sites should be more highly integrated than plants from rich sites and that plants would benefit if they were plastic in their degree of integration. Tracers were used to study the transport of w

A large number of legal rules create an obligation to prevent, repair or otherwise mitigate damage to human health or the environment. Many of these rules require that a legally relevant causal relation between human behaviour and the damage at issue is established, and in the establishment of causal relations of this kind scientific information is often pressed into service. This thesis examines

Popular Abstract in Swedish Ett antal optiskt aktiva metalloorganiska Phe-AAn-Phe subenheter har syntetiserats via intramolekulär cyklisering av motsvarande bis(aminosyra)derivat. Bis(aminosyra)derivaten var i sin tur erhållna från en förbättrad multistegssyntes, vars nyckelsteg är Horner-Wadswort-Emmons olefinering av metalloorganiska aldehyder med fosfonylglycin-reagens, enantioselektiv hydrogenSeveral optically active organometallic Phe-AAn-Phe peptidomimetics and macrocyclic Phe-(Phe)n peptides have been synthesized by either intra- or intermolecular peptide bond formation of the corresponding bis(amino acid) derivatives. The key bis(amino acid) derivatives were available from an improved multi-step synthetic route, utilising Horner-Wadswort-Emmons olefination of organometallic aldehyd

Christopher Polhem (1661-1751), called the father of Swedish mechanics, is the most famous figure in Swedish history of technology and our nation's foremost inventor ever. Remarkably enough, a close survey in a monograph has never been written on this inventor who in many ways initiated the technical and industrial development of Sweden. In this project will Polhem for the first time get a broad a