The topic of this thesis is occupancy mapping for mobile robots, with an emphasis on a novel method for continuous occupancy mapping using Gaussian processes. In the new method, spatial correlation is accounted for in a natural way, and an a priori discretization of the area to be mapped is not necessary as within most other common methods. The main contribution of this thesis is the construction of a Gaussian process library for C++, and the use of this library to implement the continuous occupancy mapping algorithm. The continuous occupancy mapping is evaluated using both simulated and real world experimental data. The main result is that the method, in its current form, is not fit for online operations due to its computational complexity. By using approximations and ad hoc solutions, the method can be run in real time on a mobile robot, though not without losing many of its benefits.

The fracture toughness of the zirconium alloy (Zr-2.5Nb) is an important parameter in determining the flaw tolerance for operation of pressure tubes in reactor. Fracture toughness data have been generated by performing rising pressure burst tests on sections of pressure tubes removed from operating reactors. The test data were used to generate a lower-bound fracture toughness curve, which is used in defining the operational limits of pressure tubes. The thesis presents a comprehensive statistical analysis of burst test data and develops a multivariate statistical model to relate toughness with material chemistry, mechanical properties, and operational history. The proposed model can be useful in predicting fracture toughness of specific in-service pressure tubes, thereby minimizing conservatism associated with a generic lower bound approach.

This paper is analyzing the unemployment duration difference of individuals under different high school programs in Sweden. The cause of the analysis has from stemmed from different fields of study and its effect on employment positions in the labour market. We see education as a factor of key importance. In addition to research on an education level, the type of study also plays an important role. Therefore, how different school programs affect unemployment duration becomes the central question we try to answer in this paper. To pursue a clear analysis structure, we start with previous studies on an education level and show the author’s interest into the research of the field of study’s effect on unemployment. Job search theory is applied to do analysis on the data. Then, an empirical analysis of unemployment duration is conducted. This is done through linear regression using the least-squares method. Finally, conclusions are made as well as some policy implications and ideas for further research.

The fracture toughness of the zirconium alloy (Zr-2.5Nb) is an important parameter in determining the flaw tolerance for operation of pressure tubes in reactor. Fracture toughness data have been generated by performing rising pressure burst tests on sections of pressure tubes removed from operating reactors. The test data were used to generate a lower-bound fracture toughness curve, which is used in defining the operational limits of pressure tubes. The thesis presents a comprehensive statistical analysis of burst test data and develops a multivariate statistical model to relate toughness with material chemistry, mechanical properties, and operational history. The proposed model can be useful in predicting fracture toughness of specific in-service pressure tubes, thereby minimizing conservatism associated with a generic lower bound approach.

Transportation accidents and the resulting fires are an important field of study. At the University of Waterloo Live Fire Research Facility (UWLFRF), an experiment was conducted in partnership with Sandia National Laboratories in Albuquerque, New Mexico. This experiment was designed to simulate an aircraft accident where fuel is spilled on the runway and is subsequently ignited. A crosswind pushes the 2.0 m diameter pool fire towards the aircraft fuselage and the conditions around the fire are monitored. Literature on the subject is examined first, examining the relationship between the fire, the crosswind, and the 2.7 m diameter blocking object (aircraft fuselage). A full wind characterization is then presented of the UWLFRF both with and without the blocking object in place, using five distinct wind speeds ranging from 3 m/s to 13.5 m/s. Turbulence intensity measurements are made on the centerline of the facility when possible. Details about the two sets of live fire tests are presented, a control experiment without the blocking object in place and then fire tests with the blocking object in place. Additionally, the control experiment has two different setups, one involving a floor surround in order to diminish the effect of the forward facing step on the front of the fuel pan. The fuel regression rate, the wind speed, the ambient conditions and the heat flux near the fuel pan are monitored during each live fire test. The fuel regression rate, defined as the rate at which the height of the liquid fuel level decreases as the fire burns, is then analyzed versus all other monitored variables. During no blocking object tests, trends of increasing wind speed and increasing heat flux on some gauges and decreasing flux on others was observed with increasing fuel regression rate when the floor surround was in place. During no blocking object tests without the floor surround and tests with the blocking object in place, no strong trends were observed when comparing the monitored variables. The ambient conditions were not observed to have an effect on any test. The average fuel regression for tests without the blocking object in place is 4.0 mm/min without the floor surround, and 4.4 mm/min with it in place. With the blocking object in place the average fuel regression rate was measured to be 4.8 mm/min using load cells and 4.1 mm/min using the sight glass.

Enligt Grossman och Krueger, finns det ett samband mellan BNP och utsläpp där utsläppen följer en inverterad U-kurva, en så kallad Kuznetskurva. För att undersöka om detta påstående stämmer har historiska data över BNP och koldioxidutsläpp inhämtats från perioden 1860-2000. Syftet med denna uppsats är att med hjälp av kointegrationsanalys undersöka om det finns någon form av samband mellan dessa serier. För att kunna göra detta har villkoren för kointegration redogjorts och undersökts för dessa serier. Resultaten i undersökningen visar att empiriska stöd har erhållits för den hypotetiska Kuznetskurvan. Däremot hittades inte empiriska indikationer för ett linjärt, monotont växande samband. Slutsatsen utifrån detta är att Sverige precis har passerat brytpunkten och att man, åtminstone i nuläget, har brutit sambandet mellan ekonomisk tillväxt och ökade koldioxidutsläpp.

Vilka faktorer är av vikt för att uppnå ekonomisk tillväxt? Kring denna fråga har det ständigt debatterats. Det är viktigt för ett land hur dess ekonomiska tillväxt fungerar, hur de uppnår detta kan ske på olika sätt och vad som påverkar den ekonomiska tillväxten finns det blandade meningar om. Syftet med uppsatsen är att undersöka samt förklara vilka faktorer som skapar denna ekonomiska tillväxt, vi kommer undersöka detta genom att titta på den grupp som kallas för utvecklingsländer. Det finns tidigare studier inom detta område men de vi har sett till har delade meningar, vilken om någon specifik faktor som bidrar till ekonomisk tillväxt mer än någon annan. Däremot så finns det gott om tillväxtteorier som försökt förklara vilka faktorer som påverkar tillväxten, vilka vi har använt oss av för att förklara resultatet av analysen. Vi har använt oss av en linjär regressionsmodell, där den beroende variabeln ekonomisk tillväxt är representerad av förändringen i bruttonationalprodukten per capita. Modellen har testat gentemot åtta stycken oberoende variabler som anses kunna påverka tillväxten och på så sätt har vi kunnat se var utvecklingsländers tillväxt kan komma ifrån. Data som använts i denna undersökning är sekundärdata, som kommer från internationella organisationer. Resultatet som vi fick fram kom att visa att tre av våra variabler var av signifikant betydelse för den ekonomiska tillväxten i utvecklingsländerna. Dels var det vilket statsskick som länderna i fråga hade, dels hur stor del av bruttonationalprodukten som bestod av utländska direktinvesteringar, och sist var även ländernas populationstillväxt av betydelse för hur väl landet lyckades uppnå ekonomisk tillväxt.

År 2007 är det högkonjunktur och arbetslösheten sjunker i Sverige. Fler väljer att läsa vidare på högskola och universitet och färre människor föds. En attraktiv arbetsplats vinner konkurrensen om den kompetens som finns. Arbetslivsinstitutet startade därför, tillsammans med Högskolan Dalarna, ett gemensamt forskningsprojekt 2001 som avslutades 2003. Projektet resulterade bla. i enkäten ”Frågor kring attraktivt arbete”. Denna enkät har ett brett innehåll och reliabilitet har ej beräknats på ett tillfredsställande sätt. Genom beräkning av korrelation, faktoranalys, cronbach´s alpha samt multipel regression kunde ett steg i att förbättra enkätens kvalitet tas. Denna studie visade att stimulans har störst betydelse för huruvida ett arbete är attraktivt eller inte. Nästa steg i förbättringen av enkäten kan vara att ifrågasätta de tre nuvarande kategorierna denne är uppdelad i samt att göra liknande beräkningar på en större mängd data.

Objectives: This Study wanted to analysis the characteristics of the elder adult who had hospitalized with pneumonia. We also evaluated the factors that will affect the unexpected readmission in elderly pneumonia patients. Methods: This is a retrospective cohort study design. The study data was collected 341 pneumonia patients who have hospitalized in a general teaching hospital in Kaohsiung city from year 2009 to 2010. The study population was divided into two groups, the sample size of the old group (age >= 65yrs), and the young group (age < 65yrs) was 173 and 168, respectively. The methods of stepwise multiple logistic regressions were needed to evaluate the association between aging and different days of unplanned readmission in adult pneumonia patients. Results: All the 341 adult pneumonia patients, we found 613 male and 926 female. The demography characteristic of the study subjects, the means of age was 61.9yrs (s.d. = 19.3yrs), and BMI was 23.4 kg/m2 (s.d. = 4.5 kg/m2). The percentage of ICD-9-CM that code 486 was 95.6%. Most patients were community-acquired pneumonia (98.8%), hospitalized from emergency room (85.3%), and admission in general wards (92.7%). The unplanned readmission within 14/30 days, 60 days, and 90days were 9.1%, 11.7%, and 15.0%, respectively. The significant factors that were associated with readmission within 14 days include age, Hb, hospitalized days, hypertension, and other disease. When we used the multiple logistic regression analysis to adjust the other variables, only age still significant with readmission within 14 days (the crude OR of the old group was 4.561, adjusted OR was 2.714, 95% CI of OR from 1.002 to 7.353). In the stepwise multiple logistic regression models, the variable that was associated with readmission with 14 or 30 days were age (>= 65yrs, OR = 3.025), WBC (>=10750 mm3, OR=2.917), and Hb (>=12.4 g/dL, OR=0.390). We remain the elderly subjects to evaluate the factor that will influence readmission states. In all the stepwise logistic regression models, we found the experience with used endotracheal tube in the hospitalized period were the significant increases the readmission rate within 14 or 30 days, 60 days, and 90 days. Conclusion: In our study shows that the situations of unexpected readmission in pneumonia patients were strong association with aging. We suggest that the indicator of medical quality should be adjusted before we comparison the readmission rate in the different institute. The major factors that will be associated to affect the readmission states were endotracheal tube used (significant with 14 or 30 days readmission rate), CRP level (significant with 60 days and 90 days readmission rate), and Hb level (significant with 60 days and 90 days readmission rate).

Prediction systems for College Entrance Examination (CEE) are popular during the graduating season, July every year in Taiwan. These systems give students suggestion according to their examination scores. There are several CEE prediction systems in Taiwan, but most of them are not constructed with rigorous theories. In 2005, Zen et al. constructed a prediction model using statistical method, which was later verified and improved by Lin in 2008. In this thesis, we will introduce the recording mechanism of the College Entrance Examination, and explain how to construct a prediction system under this mechanism. Also, we will compare the previous system with ours. We apply an empirical method and SVR as our first two approaches, and then we propose a new method. In our experiments, we consider the scores published by CEE center from 2004 to 2008. We use the root mean square error (RMSE) value to evaluate the performance of our present method. We also use the value generated by our method to show some information of the schools and the departments.