<p>I denna rapport predikteras livslängden, med avseende på utmattning, för en hjullastarskopa. Två av de mest kritiska svetsarna utvärderas enligt IIW:s (International Institute of Welding) rekommendationer genom nominella spänningsmetoden, hot spot-metoden och effective notch-metoden. Beräkningarna utförs med hjälp av finita elementmetoden. Genom att utföra töjningsmätningar på hjullastarskopan i drift erhålls spänningsdiagram. Dessa uppmätta spänningsdiagram analyseras med rain-flow count-metoden. Med ett antaget samband mellan rain-flow count-histogrammet och de beräknade spänningarna i svets och givarposition, konverteras rain-flow count-histogrammet till att gälla svetsen. Livslängsberäkningarna baseras på de konverterade rain-flow count-histogrammen.</p>

I denna rapport predikteras livslängden, med avseende på utmattning, för en hjullastarskopa. Två av de mest kritiska svetsarna utvärderas enligt IIW:s (International Institute of Welding) rekommendationer genom nominella spänningsmetoden, hot spot-metoden och effective notch-metoden. Beräkningarna utförs med hjälp av finita elementmetoden. Genom att utföra töjningsmätningar på hjullastarskopan i drift erhålls spänningsdiagram. Dessa uppmätta spänningsdiagram analyseras med rain-flow count-metoden. Med ett antaget samband mellan rain-flow count-histogrammet och de beräknade spänningarna i svets och givarposition, konverteras rain-flow count-histogrammet till att gälla svetsen. Livslängsberäkningarna baseras på de konverterade rain-flow count-histogrammen.

This work investigates births to white, African American and Hispanic adolescents in Hillsborough and Pinellas Counties, Florida, from 1992 to 1997 in two age groups - 13 to 17 year-olds and 18 to 19 year-olds - using spatial statistical techniques along with key informant interviews to provide insights into the utility of the research findings. The research developed a method for estimating the adolescent population in inter-census years, which was used to determine denominators for calculating teen birth rates. It also developed a composite deprivation index using socioeconomic indicators at the census block group level. The index provided context for hot and cold spot analysis, areas where expected teen birth rates were statistically higher or lower than expected. The association between socioeconomic deprivation in a neighborhood and rates of teen births was inconclusive, indicating a need for further research. Next steps include investigating individual-level risk and protective factors using multi-level modeling and cluster analysis as alternate analytic methods, and conducting ethnographic investigation to help provide context to the neighborhoods.

This research focuses on the Crash Analysis Methodology for Segments (CAMS) which provides a way for engineers at the Utah Department of Transportation (UDOT) to prioritize safety improvements on state-owned roadways. Unlike the Utah crash analysis methodologies that come before it, the CAMS focuses exclusively on segment-related crashes. The benefits of such an analysis can be found in identifying locations that have safety concerns unbiased from intersections and their related crashes. The CAMS uses UDOT data to create a spreadsheet of roadway segments and their associated crashes. Each segment is homogeneous with respect to five variables: Annual Average Daily Traffic (AADT), functional class, number of lanes, speed limit, and urban code. In the statistical analyses performed on the data, four years of crash data (2014-2017) are used to predict distributions of crashes for the most recent year of data (2018). Observed crash counts are compared to the predicted distributions and assigned a percentile value within the distributions, and segments are subsequently ranked in order of safety concern according to those percentiles. Two-page technical reports are created for segments that rank high in the state or UDOT Region. These reports consist of concise tables of roadway data and crash trends pertaining to each segment. Research analysts also add observations made in virtual site visits to the reports. In the end, the results and the reports are sent to UDOT where UDOT Region engineers may review and study identified segments in further detail. This research also includes modifications made to the Intersection Safety Analysis Methodology (ISAM) which focuses exclusively on intersection-related crashes. The modifications made to the ISAM mirror the abilities of the CAMS, thus allowing the pair of methodologies to analyze the entire state route network without overlapping any crash data.

Brott mot person i offentlig miljö är en av de brottskategorier som skapar störst otrygghet i det svenska samhället. Under 2018 anmäldes totalt 5101 brott mot person i offentlig miljö i Malmö, vilket är cirka 10% av de totalt anmälda brotten i Malmö. För att minska brott i offentlig miljö krävs det att polisen arbetar effektivt och på rätt platser. Tidigare forskning visar på att arbete med ”hot spot” är en effektiv metod inom det polisiära brottspreventiva arbetet och ”harm spot” kan vara ett bra alternativ till att förbättra arbetet ytterligare. I denna uppsats är syftet att ge polisen ytterligare information om var den allvarligaste brottsligheten i Malmö sker. Detta genom att undersöka och presentera ”hot & harm spot”-kartor som jämför brottsligheten i Malmös delområden. Studien ämnar delvis att visa var brotten med högt skadevärde sker och om det verkligen sker i de särskilt utsatta områdena, Lindängen, Seved och Rosengård (NOA 2017), eller om det sker över hela Malmö. Studien ämnar även att undersöka om ”hot spots” och ”harm spots” stämmer överens gällande var brottsligheten i offentlig miljö begås. Resultaten i studien tyder på att brott i offentlig miljö framförallt sker i de centrala delarna i Malmö och att de platser som beräknas ha högst skadevärde finns i Lindängen och i centrum. Det vill säga enbart i ett av tre särskilt utsatta områden. / The public crime is the type of crime that makes people feel most unsafe in the Swedish society. During 2018 there was a total of 5101 criminal notifications of crimes against people in public spaces in the city of Malmö, which is approximately 10% of all reported crimes in Malmö. It is important for the police to work efficiently and with precision to reduce the public crime. ”Hot spot policing”, as an method for the police, is shown to have good results in making their work in reducing crime more efficient and ”harm spot policing” could be an alternative to make their work even more efficient. The main goal of this study is to give the Malmö police more knowledge about where the most serious crime in Malmö occur, by using the ”Swedish Crime Harm Index” made by Rinaldo (2015). The aim is to compare and to present the public crimes in particularly deprived areas and the remaining Malmö by using ”hot-” and ”harm spot” maps. According to the “Nationella operativa avdelningen” (2017) there are three particularly deprived areas in Malmö, which is Lindängen, Seved and Rosengård. The study will also look into if the ”hot spots” and ”harm spots” will differ in the places where the crimes is commited. The result in this study mainly show that the most crimes occur in the central parts of Malmö and the crimes with highest harm value occur in Lindängen and the central areas. Which means in only one out of three of the particularly deprived areas.

Sidewalks provide many community services, yet not much geospatial research exists regarding sidewalks, especially in Mississippi. The purpose of this thesis was to use geographic information systems to inventory and map sidewalks for Starkville, MS and to compare sidewalk availability and quality to 2010 US census block demographics. In Starkville, sidewalks served 28% of the census block population, which classifies the city as “Car-Dependent” according to a Walk Score criteria. Majority minority census blocks and majority white census blocks had similar proportions of sidewalks. However, 97% of “Excellent” quality and 64 more sections of ADA compliant sidewalks were within majority white census blocks or commercial census blocks. Residential census blocks, especially majority minority blocks, have 26% less connectivity and an overall less dense sidewalk network. Starkville sidewalks have greatly improved since initial construction, but it seems that the current sidewalk infrastructure still reflects historical settlement and zoning patterns.

Traffic accidents is one of the major causes of fatalities and economic loss around the world. Thus, there is an urgent need for a better understanding about the factors that contribute to accidents so that the accidents can be prevented in the future. The research objective of this thesis is to analyze the traffic accidents between vehicles and unprotected road users (pedestrians and bicycles) in Stockholm, finding spatial distribution patterns, related attributes and examining relationships between accidents and a number of vehicle flows. The data is first analyzed with general statistical analysis to examine the basic characteristics. There is no apparent trend of change among the number of accidents per year, while the numbers of accidents happening from May to October is higher than the rest of the year except for July due to less traffic during holiday period. Most traffic accidents occur in overcast weather, on a dry road surface, or during the day. In the spatial analysis part of the thesis, Global Moran’s I is used to detect whether there is an attribute-related spatial distribution pattern. Hot spot analysis is then applied on the clustered attributes to find significant hot and cold spots over the study area. The conclusions are that road surface conditions and occurrence time during day/night are two related factors that influence traffic accidents while weather is not considered a related attribute since the accidents distribute randomly in terms of weather, of which it is difficult to obtain temporally-aligned, detailed local information for further analysis. Different parameters are selected and discussed during the process. When calculating the distance between two accidents in traffic accident analysis, Manhattan distance is more appropriate than Euclidean distance since traffic accidents are restricted to the road network. The distance band determines scales of analysis tools, with 50 meters on an intersection and 500 meters for a larger region in Stockholm. Most hot spots arise at intersections and roundabouts where different types of traffic flows meet each other. The result of the relationships between traffic accidents and different types of vehicle flows shows that the correlation coefficients between number of traffic accidents and traffic flows are low, meaning that there is no obvious correlation between them, which is also proved by the scatter plots. Poisson regression model is applied on the traffic accident data. As a result, high-risk and low-risk areas in Stockholm are pointed out. Some are consistent with the hot-spot analysis result.

Genom åren har det konstaterats att brott inte sprider sig jämnt över ett lanskap. Istället har det visat sig att vissa platser är mer brottsattraktiva än andra. Dessa platser kallas ofta för hot spots och kunskapen om dessa har bidragit till framväxten av platsbaserad och platsspecifika brottsförebyggande insatser. I samband med dessa insatser diskuteras ofta effekter såsom omfördelning och positiva spridningseffekter. Denna uppsats ämnar att undersöka omständigheterna bakom framförallt positiva spridningseffetker. Omständigheterna bakom positiva spridningseffekter har undersökts genom en systematisk översikt av studier som rapporterat om eller utvärderat en platsbaserad intervention eller experiment. Inga uppenbara gemensamma faktorer eller samband kunde urskiljas mellan de olika studierna gällande när positiva spridningeffekter sker och det kan konstateras att fenomenet är mycket komplext. Resultaten analyseras och förstås med hjälp av rutinaktivtetsteorin samt genom teorin om rationella val. Uppsatsen bygger på bevisen om att fler studier med positiva spridningseffkter i fokus bör genomföras. Genom att förstå när, var och varför spridningseffekter sker ökar också kunskapen om de preventiva insatserna och hur de kan designas för att nå bästa möjliga resultat. / Throughout the years it has been suggested that some places attract crime more than others. Those places are called hot spots of crime and the knowledge of them have contributed to the emergence of hot spot and targeted policing interventions. Hot spot policing is often discussed together with effects such as displacement of crime and diffusion of benefits. Through a systematic review of earlier studies that report or examine a hot spot policing effort or experiment this thesis aims to investigate the circumstances behind diffusion of benefits. No apparent commonalties or correlations are found between the different types of interventions regarding when diffusion of benefits occur. It can be concluded that the phenomenon is very complex. The results are analyzed and understood with the help of routine activity theory and rational choice theory. This thesis adds to the body of evidence that more studies with diffusion of benefits in focus need to be conducted. By understanding when, where and why diffusion of benefits occur the knowledge of crime prevention increases and also increases the knowledge of how to design the interventions to reach the best preventive gains.

Orthotropic steel deck has been widely used over the decades especially on long-span bridges due to its light weight and fast construction. However fatigue cracking problems on the welds have been observed in many countries. Rib-to-deck welds need special care since they are directly under wheel loads, which cause large local stress variations and stress reversals. Currently the only requirement by AASHTO bridge code is that the rib-to-deck welds need to be fabricated as one-sided partial penetration welds with minimum penetration of 80% into the rib wall thickness. However considering the thin rib plate thickness, it is very difficult to achieve this penetration without a "melt-through" or "blow-through" defect. Large cost has been caused for the repair. However recent research has found that the fatigue performance of the rib-to-deck weld is not directly related to its penetration. Other factors contribute to the fatigue performance as well. Therefore, alternative requirements which are more cost-effective and rational are desired. The objective of this research is to provide recommendations to the design and fabrication of rib-to-deck welds by investigating their fatigue performance with different weld dimensions, penetrations, and welding processes. Fatigue tests were performed to 95 full-scale single-rib deck segments in 8 specimen series fabricated with different welding processes and root gap openness. Specimens were tested under cyclic loads till failure. Three failure modes were observed on both weld toes and the weld root. Test results showed that the fatigue performance was more affected by other factors such as failure mode, R-ratio and root gap openness, rather than the weld penetration. The failure cycles were recorded for the following S-N curve analysis. Finite element analysis was performed to determine the stress state on the fatigue cracking locations. Special considerations were made for the application of hot-spot stress methodology, which post-processes the FEA results to calculate the stress values at cracking locations with the structural configuration taken into account. The hot-spot stress range values were derived and adjusted accounting for the fabrication and test error. Hot-spot S-N curves were established for each specimen series. Statistical analyses were performed to study in depth the effect of weld dimensions and test scenarios. Multiple linear regression (MLR) was performed to investigate the effects of different weld dimensions; and multi-way analysis of covariance (Multi-way ANCOVA) for the effects of specimen series, failure mode, R-ratio and weld root gap. It was found that the weld toe size was more relevant to the fatigue performance, other than the weld penetration. The failure mode and R-ratio were very influential on the fatigue performance. Recommendations to the weld geometry were proposed based on the MLR model fitting. S-N data were re-categorized based on ANCOVA results and the lower-bound S-N curve was established. AASHTO C curve was recommended for the deck design. / Master of Science

Ce premier travail de thèse sur les plantes non vasculaires de La Réunion visait à mesurer et à expliquer la diversité des communautés de bryophytes à différentes échelles de perception. Les résultats ont confirmé que les bryophytes constituent un compartiment majeur de la biodiversité à La Réunion représentant actuellement 753 espèces. Cette étude en trois ans a mis en évidence la présence d'environ 100 taxons nouveaux pour l'île et une espèce nouvelle pour la Science ce qui souligne le besoin d'échantillonnage d'un tel groupe biologique. L'utilisation du site naturel expérimental que sont les coulées de lave du Piton de la Fournaise a permis d'étudier pour la première fois la dynamique de la végétation des bryophytes et de mettre en évidence une forte diversité spécifique le long d'une chronoséquence de six coulées de laves à basse altitude (~ 304 ans) et d'un gradient altitudinal (250 - 850 m) sur la coulée 1986. Cette diversité est principalement représentée par les hépatiques, plus particulièrement la famille des Lejeuneaceae. L'analyse de la distribution spatiale des bryophytes à une échelle fine le long de ces gradients a montré un turn over des microhabitats et de sa bryoflore associée en fonction de l'age des coulées et de l'altitude, et du rôle prédominant de la présence et la disponibilité de ces microhabitats dans la structuration des communautés bryophytiques. Vingt six groupements de bryophytes ont été caractérisés pour ces coulées. Le patron biogéographique des espèces recensées sur ces coulées de laves reflète principalement une origine africaine (66.5 % des espèces) suivi par des espèces à plus large distribution (pantropicale, paléotropicale, subcosmopolite et disjoncte entre l'Amérique et l'Afrique). A plus large échelle, cette étude s'inscrit dans un programme de recherches visant à obtenir une meilleure connaissance de la diversité bryophytique et de l'écologie des espèces pour la zone ouest de l'océan Indien (Réunion, Comores, Seychelles, Maurice, Madagascar) en vue d'une meilleure stratégie de conservation et de gestion du patrimoine naturel de ce hot spot de biodiversité.