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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 Ă 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 searchersâ 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 anvĂ€nda skapande arbete som vĂ€g till platskĂ€nnedom och bas för ett koncept för en plats, med ett omrĂ„de i Gottsunda/ValsĂ€tra, Uppsala, som exempel. Jag utarbetade tio undersökningsmetoder med skapande arbete som gemensam nĂ€mnare och prövade dem pĂ„ omrĂ„det. Undersökningsmetoderna var skilda varandra i utförande. Jag byggde modeller, gjorde kĂ€nsloskisser, seriella vyer, tecknade konturer och mellanrum, skissade pĂ„ natten, gjorde collage, karikatyrer, promenerade och tecknade samtidigt, samt tecknade reflekterande skisser. Jag tolkade resultatet frĂ„n undersökningsmetoderna och drog slutsatser ifrĂ„n det. Slutsatserna analyserades och anvĂ€ndes som material till att utforma ett program för omrĂ„det. Detta följs av nĂ„gra koncept för omrĂ„dets framtida utformning. âVĂ€stra parkenâ bygger pĂ„ att skapa social interaktion genom att tillhandahĂ„lla bostadsnĂ€ra odlingsytor med fokus pĂ„ Ă€tbara vĂ€xter och grödor. I förslaget âTorgytorâ skapas ett lĂ„ngsmalt torg. Uteserveringar, torghandel och schackspel inramat av körsbĂ€rstrĂ€d. En sekvens av rum möter flanören som passerar âĂstra parkenâ. Förutom grönskande uterum skapas en scen samt tvĂ„ mĂ„larvĂ€ggar. Detta ger möjlighet för de boende att uttrycka sig i flera olika medier och fĂ„ utlopp för sin kreativitet, sina kĂ€nslor och kanske Ă€ven den frustration och ilska jag kĂ€nt existerar i omrĂ„det under mitt skissande. âBostadsgĂ„rdâ Ă€r ett koncept som visar hur den sociala zoneringen kan förbĂ€ttras pĂ„ omrĂ„dets bostadsgĂ„rdar. Konceptet âFasadâ visar nĂ„gra exempel pĂ„ Ă„tgĂ€rder som livar upp omrĂ„dets pĂ„ mĂ„nga platser grĂ„a fasader. Som avslut pĂ„ vyn frĂ„n omrĂ„dets huvudentrĂ© skapade jag konceptet âLekparkâ. En hög skulptur markerar hĂ€r gatans slut och kring denna ligger en lummig lekpark för alla Ă„ldrar. En intressant iakttagelse Ă€r att man med min skissmetod faktiskt fĂ„r en skiss tillbaka i sitt medvetande, en skissartad bild över hur ett omrĂ„de upplevs. Min upplevelse Ă€r att skissandet kortade ner startstrĂ€ckan för gestaltningsarbetet. Jag tror detta berodde pĂ„ att jag blev instĂ€lld pĂ„ att skapa och skissa tidigt i processen. PĂ„ sĂ„ sĂ€tt, tror jag, kan min metod inte bara vara en vinst i platskĂ€nnedom, utan Ă€ven i tid. Jag vill att det hĂ€r arbetet skall vara en tankestĂ€llare för lĂ€saren och slĂ„ 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/ValsĂ€tra, 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 . "VĂ€stra 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 âTorgâ, 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 âĂstra parkenâ, 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. "BostadsgĂ„rd" shows how the residential courtyards can be improved in the area. âFasadâ shows a couple of examples on how the dull facades in the area can be improved. The concept âLekparkâ, 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
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