Hot spotting of automotive disc brakes is an undesired thermal localisation phenomenon, which is a challenge for numerical modelling in terms of both accuracy and efficiency especially for complex disc geometry. In this research, the aim was to develop a computationally efficient finite element (FE) approach for 2-piece pin-mounted ventilated disc hot spot prediction with acceptable accuracy enabling parametric studies to contribute to the knowledge of the complex mechanisms. A time reduction strategy for the simulations was established by incorporating an axisymmetric brake pad assumption with material scaling factor and the friction characteristics were defined by a user-subroutine. The computing accuracy and efficiency of this method were then verified by comparing with traditional FE models. 2D in-plane, 2D out-of-plane, and 3D models were performed to investigate the effects of ventilated disc hot spotting, radial hot spot/band migration, and hot spotting of realistic complex disc geometry respectively. Both 2D and 3D results were validated using experimental results based on a laboratory dynamometer and showed good correlation. The results suggested that adequate modelling of friction pair contact pressure distribution and the subsequent non-uniform heat generation is essential for hot spot simulation; speed was identified as the determinant for the number of hot spots, whereas hot spot temperature was determined by energy level. Furthermore, recommendations for vent design, pins, disc run-out, cooling, material selection, wear rate, pad length and loading distribution were given. Finally, hot spotting and hot band migration cause-effect chains were established based on the results and discussion. / Appendix 1 and Appendix 2 are unavailable online due to copyright restrictions.

Budgets for transportation improvements are limited so it is important for governments to focus on improving locations most in need of safety funding. The objective of the Two-Output Model for Safety (TOMS) is to provide the Utah Department of Transportation (UDOT) a reliable method to prioritize safety improvements on state-owned roadways among the different regions. This research will improve the existing Crash Analysis Methodology for Segments (CAMS) and Intersection Safety Analysis Methodology (ISAM) being used to analyze crashes on Utah roadways. The scope of this project is improving on the existing CAMS and ISAM to work together within R, to incorporate segment and intersection severity in safety hot spot analysis, to develop overall severity distributions, and to develop limited recommendations and conclusions related to the research. TOMS uses UDOT data to create a statistical input. Each segment is homogenous with respect to five variables: average annual daily traffic, functional class, number of through lanes, speed limit, and urban code. Intersections are provided as a separate dataset. In the statistical analyses performed on the data, five years of crash data (2016-2020) are used to determine a weighted risk score for segments and intersections of similar characteristics. Those segments or intersections with excess weighted risk scores are designated as crash hot spots. Two-page technical reports with road characteristics and crash data are created for the top 10 hot spots for segments and intersections in Utah. The reports are sent to UDOT where region engineers may review and determine which locations might be addressed.

This study uncovered the pattern and spatial relationships between socio-economic factors and aggregated COVID-19 rates in Ottawa, Canada, from July 2020 to December 2021 at the neighbourhood scale. Both top-down and bottom-up data mining approaches were used to predict COVID-19 rates. The top-down approach employed ordinary least squares regression (OLS), spatial error model (SEM), geographically weighted regression (GWR) and multi-scale geographically weighted regression (MGWR). Model intercomparison was also undertaken. The pattern of COVID-19 in Ottawa exhibited a significant moderately positive spatial structure among neighbourhoods (Moran's I = 0.39; p = 0.0001). Local Moran's analysis identified areas of low and high COVID-19 clustering, interspersed with cold spots. The OLS model used determinants based on a literature review. Determinants were tested for normality using the Shapiro-Wilks test with those that failed the test had transformatoins to normality applied. Next, an OLS-based backward stepwise approach was used to select the optimal set of determinants based on goodness of fit, selecting the model with the lowest Akaike Information Criterion (AIC). The percentage of people who take public transit to work, percentage of people with no high school diploma, percentage of people over 65 years old, and percentage of people with a Bachelor level degree or above comprised the final set of determinants. A SEM model was created to account for residual spatial autocorrelation in the OLS model's residuals and yielded an adjusted R² = 0.63. Based on the SEM, a one-unit increase in the square root of the percentage of people with a bachelor's degree or above was associated with a 3.2% increase in COVID-19 rates, while the same unit increase in the square root of the percentage of people with no high school diploma was associated with a 10.6% increase in COVID-19 rates. Conversely, a one percent increase in the percentage of people aged 65 and older was linked to a 34.6% decrease in COVID-19 rates. To examine local variations in the relationships between the determinants and COVID-19, a MGWR with a Bisquare kernel and an adaptive bandwidth was used to improve upon the overall explained variance of the SEM model. The residuals of the MGWR model exhibited no significant spatial autocorrelation (Moran's I = -0.04; p = 0.62) and residuals were approximately normal (W = 0.98; p > 0.25). The MGWR model yielded an adjusted R² = 0.75. Taking a data mining and bottom-up approach, an optimized Random Forest model provided a very different set of determinants as important when compared to the top-down regression approaches and accounted for 47.34% of the COVID-19 variance.

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This study examined the effectiveness of helicopter patrols in reducing violent crime rates in three Swedish cities: Malmö, Lund, and Helsingborg. Utilizing Swedish official crime records from 2016 to 2019 and helicopter data from an intervention conducted between August 9th and October 9th, 2019, the study employed quantitative methods, including multiple linear regressions and two-way fixed effects models, to analyse the impact of helicopter presence and dosage on various types of violent crimes. Findings indicated that neither helicopter presence nor dosage demonstrated a significant effect on violent crime variables across the three cities. Moreover, when included as control variables in the fixed effects models, Malmöfestivalen and weather variables did not alter the relationship between the helicopter intervention and any of the violent crime variables. The study concludes that helicopter patrols lack a deterrent effect on violent crimes, suggesting the need for reallocating resources to more effective policing strategies. Suggestions for future research include exploring other crime types, conducting cost-benefit analyses, and investigating the long-term implications of helicopter patrols.

On assiste aujourd’hui au développement massif des technologies nomades. L’utilisation de boîtiers compacts est ainsi en plein croissance, non seulement à cause des téléphones portables et tablettes, mais aussi à cause de l’introduction massive de l’électronique dans les appareils portables de la vie quotidienne. La microélectronique embarquée dans ces appareils représente le principal outil d’information et de communication des personnes avec le monde extérieur. Le rythme de développement de ces technologies dans les dernières années est tel que les possibilités d’utilisation des appareils portables d’aujourd’hui étaient de la science-fiction il y a seulement 10 ans.Les fonctionnalités qui verront le jour dans les années à venir ne peuvent donc pas toutes être encore imaginées. Ces fonctionnalités vont toutefois très certainement impliquer une augmentation des performances de calcul des dispositifs, et par conséquent de la chaleur qu’ils dissipent.Aujourd’hui, on envisage des puces complexes comprenant plusieurs niveaux logiques et basées sur technologies hétérogènes. On demande également que ces technologies soient intégrées dans les appareils utilisés dans la vie quotidienne, qu’ils soient connectés entre eux et qu’ils réagissent de façon intelligente. Les stratégies de dissipation de la chaleur doivent donc être en adéquation avec la réduction des dimensions des dispositifs de la microélectronique.L’objectif de la thèse présentée dans ce manuscrit est ainsi d’étudier les stratégies de dissipation thermique des boîtiers compacts avec l’aide de répartiteurs de chaleur intégrés. Ce travail porte sur la caractérisation des performances et contraintes des répartiteurs thermiques avec matériaux carbonés. Les répartiteurs sont capables de dissiper sur sa surface la chaleur produite dans un point chaud.Afin d’étudier le phénomène de la dissipation avec un répartiteur, on a mis en place une méthodologie qui prend en compte le caractère multiniveau de la dissipation thermique. L’objectif est de pouvoir se concentrer sur l’interaction entre le répartiteur thermique et chacun des éléments de l’ensemble. On a réutilisé deux véhicules de test et on a désigné un véhicule de test spécifique pour l’étude de la thermique des puces imageurs.Les travaux sont basés sur deux axes : Les études d’intégration et les études thermiques. Les études d’intégration prennent en compte les contraintes dérivées de l’implémentation des couches répartiteurs dans des boitiers compactes. On se concentre d’abord sur les procès d’implémentation des couches répartiteurs au sein de l’ensemble dans un procès industriel. Ensuite on étudie les effets thermomécaniques et les effets sur l’intégrité des signaux à haute fréquence.Les études thermiques caractérisent le gain en performances dérivé de cette intégration. On analyse ces phénomènes thermiques avec des mesures et des simulations. Premièrement au niveau silicium et répartiteur, deuxièmement au niveau boitier et finalement on se concentre sur les effets dans une puce et boitier imageur.A la lumière des résultats on peut dire que les matériaux carbonés se présentent comme l’alternative plus intéressante pour l’implémentation à grande échelle de répartiteurs dans des boitiers compacts. Cette implémentation sera poussée par la recherche des prestations dans des boitiers de plus en plus complexes et hétérogènes, ou l’empreinte du répartiteur doit être minimale. La combination des couches de carbone a tous les niveaux du boitier, avec des TIMs des épaisseurs réduites sera la tendance dans les années à venir pour ce type de dispositifs.Cette thèse s’inscrit dans le cadre d’une collaboration tripartie entre le CEA-LETI de Grenoble, le laboratoire G2Elab de l’INP Grenoble et STMicroelectronics à Crolles. / We witness today an explosion of nomadic technologies. Portable devices have become the main tool that people use to connect with the rest of the world. The microelectronics embedded in these devices is the technology that drives this process. The pace of development of these technologies is such that the versatility of portable devices today were science fiction only 10 years ago.The functionalities that will be integrated in the coming years cannot be imagined yet. These features will imply an increase of the computing demands, and consequently, of the heat dissipated inside them. The trend leads to complex stacks with heterogeneous modules of heat dissipating layers.These technologies will be integrated in everyday life. Internet of Things, as we call it, will demand an increasing amount of independent low footprint devices that will be connected. Heat dissipation strategies must therefore be compatible with increasingly smaller dimensions. Compact packages demand is growing rapidly, not only because of telephones and tablets, but also because of the massive introduction of electronics into in everyday life devices.The objective of the thesis is to study the integration of heat-spreaders in compact packages to enhance its thermal performance. This work goes deeply in the characterization of the thermal performance of carbon-base heat spreaders. Heat-spreaders are able to extract the heat produced in hot spots and transport it along its surface.In order to study the heat spreading phenomenon, a methodology that takes into account the multi-level nature of heat dissipation has been implemented. The objective is to be able to focus on the interaction between the heat-spreader and each one of the elements of the package stack. Two test vehicles have been re-used from previous works. A specific test vehicle was also design in order to emulate the thermal behavior of imaging sensors.The thesis is based on two main axes: Integration studies and thermal studies. The integration studies take into account the constraints derived from the implementation of heat spreaders in compact packages. Firstly, we focus on the implementation processes within an industrial process. Latelly, we study the thermomechanical effects of heat spreaders and the impact on the integrity of high frequency signals.Thermal studies are aimed to characterize the performance gain derived from this heat spreader integration. The thermal phenomena are analyzed with measurements and simulations. First at silicon and interface level, then at package level, finally we focus on the effects in image sensor die and package.In the light of the results it can be said that carbon based materials are the most interesting alternative for large-scale implementation of heat spreaders in compact packages. This implementation will be driven by the research of new functionalities and performances in compact packages. The heat spreader will have to perform while maintaining a minimal footprint. The combination of carbon layers at all package levels, along with reduced thermal interface thickness will be the trend in the coming years for this type of device.This thesis is part of a tripartite collaboration between the CEA-LETI of Grenoble, the G2Elab laboratory of the INP Grenoble and STMicroelectronics in Crolles.

A Study on the Establishment of Police Work Indicator in Kaohsiung Abstract Social security is the public issue that enjoys the greatest concerns from the civil public. This study attempts to establish a set of indicators based on current situation of police patrol work and commitment in Kaohsiung, in the method of social science indicator establishment to objectively and adequately evaluate Kaohsiung police work efficiency. This essay surveys the issues concerning police work indicators referring to bibliographies of the idea of police, the procedure of patrol duty development, patrol¡¦s effectiveness on crime deterrence, type of crime and criminal indicator in Kaohsiung City. In the first part herein, the frequency of stopping, listening, and seeing while performing patrol duty by police officers serve in the eight police stations governed by Kaohsiung County Police Bureau Fengshan Police Precinct was investigated and ¡§Patrol Duty Indicator¡¨ was established accordingly. And in the second part, citizens attained the age of twenty having household registration set in Kaohsiung City were interviewed through telephone about the seriousness of different crimes on social security to have ¡§Criminal Indicator¡¨ produced. At last, the said two indicators were combined to form the Police Work Indicator. As for statistic analysis, SPSS for windows (8.0) was adopted to perform data organization and statistics. Additionally, Descriptives, Crosstabs, and £q2,Chi-square 2,Chi-square test ,test of independence were implemented to describe the condition and then make statistics of all indicators. From Patrol Duty Indicator, it¡¦s found that the efficiency of patrol duty is determined by the ¡§Unit Personnel Number¡¨ and ¡§Age of Policemen.¡¨ While assigning patrol duties, the police work agency shall take the two principal factors into consideration more carefully to have patrol duties fulfilled. In the respect of criminal indicator, it is concluded from individual comparison that the general public considers it¡¦s good regarding overall criminal indicator, and it is improved slightly concerning criminal indicator of violence. However, it¡¦s slightly worsened in relation to the criminal indicator of theft and drug addicts. The police work agency may observe changes in indicators and modify the measurements moderately. Key Words: Social Science Indicator, Descriptives, Criminal Indicator, Hot Spot Planning, Type of Crime, Patrol Duty Indicator, Variance Analysis, Correlation Analysis