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The integer factorisation problem (FACT) is a well-known number-theoreticproblem, with many applications in areas such as cryptography. An instanceof a FACT problem (a number n such that n = p × q) can be reduced to aninstance of the conjunctive normal form boolean satisfiability problem (CNF-SAT), a well-known NP-complete problem. Some applications of this is toutilize advances in SAT solving for solving FACT, and for creating difficultCNF-SAT instances.This report compares four different reductions from FACT to CNF-SAT,based on the full adder, array multiplier and Wallace tree multiplier circuits.The comparisons were done by reducing a set of FACT instances to CNF-SATinstances with the different reductions. The resulting CNF-SAT instanceswere then compared with respect to the number of clauses and variables, aswell as the time taken to solve the instances with the SAT solver MiniSat

Competition between employed and unemployed job applicants: Swedish evidence

We use the Swedish Job Applicant Database to empirically investigate whether being unemployed per se reduces the probability to get contacted by a firm. This database contains personal characteristics and preferences over the type of job the applicant wants to find. The data is submitted both by employed and unemployed workers over the Internet by the applicants themselves. This means that we have access to exactly the same information as firms have when they choose whom to contact. Our results show that an unemployed applicant faces a lower probability to get contacted by a firm than an otherwise identical employed applicant, thus supporting the claim that firms view employment status as an important signal for productivity.Employed and unemployed job seekers; discrimination

Detecting discrimination in the hiring process: evidence from an Internet-based search channel

This paper uses data from an Internet-based CV database to investigate how factors which may be used as a basis for discrimination, such as the searchers’ ethnicity, gender, age and employment status, affect the number of contacts they receive from firms. Since we have access to essentially the same information as the firms, we can handle the problems associated with unobserved heterogeneity better than most existing studies of discrimination. We find that, even when we control for all other differences, searchers who have non-Nordic names, are old or unemployed receive significantly fewer contacts. Moreover, we find that this matters for the hiring outcome: Searchers who receive more contacts have a higher probability of actually getting hired.Job search; Unobserved heterogeneity; Discrimination

Using enriched quality register data for health care evaluation : examples from rheumatoid arthritis

Swedish registers have for decades successfully been used for medical research, enabling long-term follow-up of large patient cohorts using observational designs. With a tax funded health care system and the use of a personal identity number as a unique identifier, together with national health registers as well as national demographic registers, we have to a relatively low cost the possibility to answer an abundance of research questions in a real-world setting. This thesis describes how the Swedish Rheumatology Quality register (SRQ) can be enriched with national register data for estimating disease occurrence, assessment of health care resource use and work loss, and for potentiating randomized controlled trials (RCTs) conducted within the register framework. More specifically, by using the SRQ that collects disease specific data on patients with rheumatic diseases in routine clinical care together with objectively assessed data from national registers we could in a large sample of patients with rheumatoid arthritis (RA) estimate the incidence and burden of RA. Furthermore, with a randomized pragmatic clinical trial included in the register framework, we could provide information on health economic outcomes regarding a common clinical question in early RA, whether to continue treatment by adding an expensive biologic alternative or to continue with a conventional combination treatment strategy after insufficient response to methotrexate. We found an overall incidence of RA in Sweden on a par with previous local but detailed studies (41 per 100,000; paper I), with a substantial variation across age and sex. We observed that the incidence of RA peaked in the 7th decade in life in both sexes, and that the incidence in women was more than twice the incidence observed in men. Furthermore, we observed lower incidence estimates in individuals with higher education level and in densely population areas. With respect to burden of disease, we used general population comparators individually matched to register-identified subjects with RA and estimated the annual societal cost in prevalent as well as monthly societal cost in newly diagnosed patients to 2-3 times higher than in the general population (paper II). The randomized Swefot trial compared the addition of the biologic drug infliximab versus conventional combination therapy in patients with early RA who had failed initial methotrexate monotherapy. With the Swefot trial included in the SRQ, we could for the first time in a randomized register trial setting analyze work loss and cost-effectiveness for a strategy adding a biologic alternative as compared to conventional combination therapy in methotrexate-refractory early RA. We observed a substantial decrease in mean monthly work loss days in both treatment alternatives, with a reduction of 3 times to double that in the general population from randomization to 21 months of follow-up, but no difference between the strategies could be detected (paper III). This remaining gap to the general population indicates a need for earlier diagnosis as well as for more effective treatment strategies of RA. In the cost-effectiveness analysis we observed similar effects between the strategies over 21 months, while the infliximab strategy incurred higher costs (paper IV), suggesting that an attempt with conventional combination therapy appears reasonable before starting infliximab treatment in methotrexate-refractory early RA, both from a clinical and economic perspective

Go out sketching! : form studies as a way to site knowledge

I arbetet visas hur man kan använda skapande arbete som väg till platskännedom och bas för ett koncept för en plats, med ett område i Gottsunda/Valsätra, Uppsala, som exempel. Jag utarbetade tio undersökningsmetoder med skapande arbete som gemensam nämnare och prövade dem på området. Undersökningsmetoderna var skilda varandra i utförande. Jag byggde modeller, gjorde känsloskisser, seriella vyer, tecknade konturer och mellanrum, skissade på natten, gjorde collage, karikatyrer, promenerade och tecknade samtidigt, samt tecknade reflekterande skisser. Jag tolkade resultatet från undersökningsmetoderna och drog slutsatser ifrån det. Slutsatserna analyserades och användes som material till att utforma ett program för området. Detta följs av några koncept för områdets framtida utformning. ”Västra parken” bygger på att skapa social interaktion genom att tillhandahålla bostadsnära odlingsytor med fokus på ätbara växter och grödor. I förslaget ”Torgytor” skapas ett långsmalt torg. Uteserveringar, torghandel och schackspel inramat av körsbärsträd. En sekvens av rum möter flanören som passerar “Östra parken”. Förutom grönskande uterum skapas en scen samt två målarväggar. Detta ger möjlighet för de boende att uttrycka sig i flera olika medier och få utlopp för sin kreativitet, sina känslor och kanske även den frustration och ilska jag känt existerar i området under mitt skissande. ”Bostadsgård” är ett koncept som visar hur den sociala zoneringen kan förbättras på områdets bostadsgårdar. Konceptet ”Fasad” visar några exempel på åtgärder som livar upp områdets på många platser gråa fasader. Som avslut på vyn från områdets huvudentré skapade jag konceptet “Lekpark”. En hög skulptur markerar här gatans slut och kring denna ligger en lummig lekpark för alla åldrar. En intressant iakttagelse är att man med min skissmetod faktiskt får en skiss tillbaka i sitt medvetande, en skissartad bild över hur ett område upplevs. Min upplevelse är att skissandet kortade ner startsträckan för gestaltningsarbetet. Jag tror detta berodde på att jag blev inställd på att skapa och skissa tidigt i processen. På så sätt, tror jag, kan min metod inte bara vara en vinst i platskännedom, utan även i tid. Jag vill att det här arbetet skall vara en tankeställare för läsaren och slå ett slag för skapande som följeslagare i landskapsarkitektens yrkesutövning.This work demonstrates how form studies can be used as a way to reach site knowledge and form the base for landscape architectural design concepts, with the geographical area of Gottsunda/Valsätra, Uppsala, as an example. I worked out ten investigative sketching techniques and tested them in the mentioned area. I built models, made emotional sketches, serial views, contours and negative spaces, sketched during nighttime, made collages, caricatures, walked and sketched simultaneously, and also drew reflective sketches. I interpreted the results of the sketching methods and drew conclusions from them. The conclusions were sorted to strenghts, weaknesses, opportunities and threats, and then used as a base for making a program for the area. The program is followed by some concepts for the area's future design . "Västra parken"is designed to provide areas for urban farming, with a focus on edible plants and crops, close to the residents in the neighbourhood. In the concept “Torg”, Squarespace, the possibility of creating an elongated square is shown. Outdoor dining, market trade and large chess boards surrounded by cherry trees on two sides. A sequence of rooms meets the visitor in the concept “Östra parken”, the East Park. In addition to the many green outdoor rooms, a stage for performances and two walls for painting and art adds life to the park. It provides an opportunity for residents to express themselves in a variety of media and also an outlet for their creativity, their feelings and maybe even the frustration and anger I felt exists in the area during my sketching. "Bostadsgård" shows how the residential courtyards can be improved in the area. “Fasad” shows a couple of examples on how the dull facades in the area can be improved. The concept “Lekpark”, playground, is built as an ending point and landmark of the view from the main entrance of the area. The exercises I made have given me a strong mental picture of the area's nooks and crannies as well as given me an understanding of how the area is structured. I felt that the take off into the creative process was shortened compared to how previous projects I have worked with passed. This was probably because my brain was set up to sketch and create after I completed my sketching exercises Creative methods of investigation can thus be an advantage in site knowledge and will also be a way of gaining time.I want this thesis to be an eye-opener for the reader and a blow for the sketch as a companion in the landscape architect's profession