Background: It is debated whether temporary employment compared to permanent employment entails an elevated risk of illness or not, as the empirical studies have not shown a unified picture. Since a significant part of the Swedish workforce is currently working under temporary employment contracts, it is important for public health research to pay close attention to what the implications in terms of illness might be. Therefore the aim of this thesis was to explore the relationship between temporary employment and illness. Methods: This thesis was based on data from the Northern Swedish Cohort, consisting of all pupils in grade 9 in Luleå in 1981 (n=1083). The cohort was followed with extensive questionnaires. The latest follow-up was performed in year 2007, when 94% participated. To analyse the quantitative questionnaire data, logistic regression and trajectory analysis were used. A qualitative method, Grounded Theory, was also applied in this thesis to analyse interviews performed in 2011, with a strategic selection of 12 participants from the cohort. Results: Quantitative data showed that temporary employees had overall higher odds ratios for illness in terms of psychological distress and non-optimal self-rated health compared to permanent employees. This general difference in odds ratios was evident irrespective of how temporary employment was measured as well as after control for earlier health status and confounders. The qualitative analysis gained insight into temporary employment as social processes of: underling the driving force for employment; working hard for a job. The structural conditions emerged in terms of, being used and exploited on the labour market and these conditions were related to the individual strategies of adaptation and coping. In the intersection of agency, structural conditions and adaption, emotional and bodily reactions emerged, such as being worn out, worried and wrathful. Conclusion: Illness is unevenly distributed between temporary and permanent employees, with temporary employees being the unfavourable group. Striving for good and evenly distributed health conditions in the population, policy makers should aim at reducing the number of employees working in temporary contracts. In addition, there is a need to improve surveillance of the health situation among temporary employees and to reduce unfavourable conditions, such as job and financial insecurity and unemployment, among temporary employees.

Orientador: Marília Vieira Soares / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-08-20T08:03:41Z (GMT). No. of bitstreams: 1 Figueiredo_ValeskaMarleteGuimaraes_D.pdf: 5415097 bytes, checksum: b6283eedb567edcc445c4eb7d83576a5 (MD5) Previous issue date: 2012 / Resumo: Esta tese busca entender como que, numa dança, a noção de corpo e a disposição espacial da cena expõem uma postura política, bem como constroem uma concepção de mundo. A dança não está apartada das esferas sociais, econômicas e políticas, pois ela é, por elas, constituída e, delas, constituinte. Pesquisou-se estas questões nas trajetórias artísticas de Sandro Borelli, diretor e coreógrafo residente da Cia Borelli de Dança, e, em Vera Sala, diretora e criadora-intérprete do Núcleo Artístico Vera Sala. Foram, nesse sentido, destacadas algumas de suas criações tidas como relevantes na construção de certos aspectos dos seus pensamentos em dança. Suas perspectivas estéticas e políticas são bem distintas, porém parecem ter em comum o interesse por questionar determinados padrões dominantes e ordens normativas. As particularidades do trabalho de cada artista exigiram um campo teórico específico para discutir cada trajetória. Assim, examinaram-se os princípios norteadores de suas pesquisas corporais, a disposição dos corpos no espaço da cena e os modos de relação entre eles, os seus procedimentos de criação, as suas formas de organização e de criação enquanto grupo. Investigando estes trabalhos, foi possível verificar que as suas criações propõem uma maneira de perceber e de atuar no mundo. Implicações estéticas e políticas da arte foram analisadas e discutidas, junto a uma gama de pensadores, chegando-se a proposição de que para a arte ser crítica precisa criar dissenso; e para ser ética necessita aumentar a potência de ação e/ou de inação de uma coletividade. Há de se fazer da inquietação instigadora do processo criativo uma forma de vida, constituindo-a corporalmente através do seu trânsito entre o cotidiano e extracotidiano. A resistência artística aos atuais esquemas de controle e exploração dá-se através do vazamento dos processos criativos. As ficções, invisibilidades, latências e lacunas podem, assim, penetrar a vida ordinária, dessa maneira, desestabilizando certas ordenações / Abstract: This thesis seeks to understand how in a dance the notion of body and spatial arrangement of the scene expose a political stance, as well as build a world view. The dance is not separated from social, economic and political spheres, as it constitutes and is constituted by them. These issues were researched in the artistic trajectories of Sandro Borelli, director and resident choreographer of the Borelli Dance Company, and Vera Sala, director and creator-interpreter of the Vera Sala Artistic Group. We highlight some of their creations, understood as relevant in the construction of certain aspects of their thoughts on dance. Their aesthetic and political perspectives are very different, but they seem to have a common interest for questioning certain dominant standards and normative orders. The particularities of each artist's work demanded a specific theoretical place to discuss each trajectory. We examined the guiding principles of their research of the body, the arrangement of bodies in space of the scene and the modes of relationship between them, their creative procedures, their organization and creation as a group. Investigating these works, we found that their creations propose a way of perceiving and acting in the world. Aesthetic and political implications of art were analyzed and discussed, along with a range of thinkers, coming to the proposition that for art to be critical, it needs to create dissent, and for it to be ethical, it needs to increase the power of action and/or inaction of a collectivity. One has to make the instigating inquietude of the creative process a way of life, building it bodily through the transit between daily and extra-daily techniques. The artistic resistance to current schemes of control and exploitation takes place through leaks in the creative processes. Fictions, invisibilities, latencies and gaps can thus penetrate ordinary life, destabilizing certain offenses / Doutorado / Artes Cenicas / Doutor em Artes

Abnormal behaviour may indicate important objects and events in a wide variety of domains. One such domain is intelligence and surveillance, where there is a clear trend towards more and more advanced sensor systems producing huge amounts of trajectory data from moving objects, such as people, vehicles, vessels and aircraft. In the maritime domain, for example, abnormal vessel behaviour, such as unexpected stops, deviations from standard routes, speeding, traffic direction violations etc., may indicate threats and dangers related to smuggling, sea drunkenness, collisions, grounding, hijacking, piracy etc. Timely detection of these relatively infrequent events, which is critical for enabling proactive measures, requires constant analysis of all trajectories; this is typically a great challenge to human analysts due to information overload, fatigue and inattention. In the Baltic Sea, for example, there are typically 3000–4000 commercial vessels present that are monitored by only a few human analysts. Thus, there is a need for automated detection of abnormal trajectory patterns. In this thesis, we investigate algorithms appropriate for automated detection of anomalous trajectories in surveillance applications. We identify and discuss some key theoretical properties of such algorithms, which have not been fully addressed in previous work: sequential anomaly detection in incomplete trajectories, continuous learning based on new data requiring no or limited human feedback, a minimum of parameters and a low and well-calibrated false alarm rate. A number of algorithms based on statistical methods and nearest neighbour methods are proposed that address some or all of these key properties. In particular, a novel algorithm known as the Similarity-based Nearest Neighbour Conformal Anomaly Detector (SNN-CAD) is proposed. This algorithm is based on the theory of Conformal prediction and is unique in the sense that it addresses all of the key properties above. The proposed algorithms are evaluated on real world trajectory data sets, including vessel traffic data, which have been complemented with simulated anomalous data. The experiments demonstrate the type of anomalous behaviour that can be detected at a low overall alarm rate. Quantitative results for learning and classification performance of the algorithms are compared. In particular, results from reproduced experiments on public data sets show that SNN-CAD, combined with Hausdorff distance  for measuring dissimilarity between trajectories, achieves excellent classification performance without any parameter tuning. It is concluded that SNN-CAD, due to its general and parameter-light design, is applicable in virtually any anomaly detection application. Directions for future work include investigating sensitivity to noisy data, and investigating long-term learning strategies, which address issues related to changing behaviour patterns and increasing size and complexity of training data.

Human operators of modern surveillance systems are confronted with an increasing amount of trajectory data from moving objects, such as people, vehicles, vessels, and aircraft. A large majority of these trajectories reflect routine traffic and are uninteresting. Nevertheless, some objects are engaged in dangerous, illegal or otherwise interesting activities, which may manifest themselves as unusual and abnormal trajectories. These anomalous trajectories can be difficult to detect by human operators due to cognitive limitations. In this thesis, we study algorithms for the automated detection of anomalous trajectories in surveillance applications. The main results and contributions of the thesis are two-fold. Firstly, we propose and discuss a novel approach for anomaly detection, called conformal anomaly detection, which is based on conformal prediction (Vovk et al.). In particular, we propose two general algorithms for anomaly detection: the conformal anomaly detector (CAD) and the computationally more efficient inductive conformal anomaly detector (ICAD). A key property of conformal anomaly detection, in contrast to previous methods, is that it provides a well-founded approach for the tuning of the anomaly threshold that can be directly related to the expected or desired alarm rate. Secondly, we propose and analyse two parameter-light algorithms for unsupervised online learning and sequential detection of anomalous trajectories based on CAD and ICAD: the sequential Hausdorff nearest neighbours conformal anomaly detector (SHNN-CAD) and the sequential sub-trajectory local outlier inductive conformal anomaly detector (SSTLO-ICAD), which is more sensitive to local anomalous sub-trajectories. We implement the proposed algorithms and investigate their classification performance on a number of real and synthetic datasets from the video and maritime surveillance domains. The results show that SHNN-CAD achieves competitive classification performance with minimum parameter tuning on video trajectories. Moreover, we demonstrate that SSTLO-ICAD is able to accurately discriminate realistic anomalous vessel trajectories from normal background traffic.

This dissertation describes research investigating the potential for using Landsat data to identify and characterize woody canopy cover on reclaimed coal-mined lands through three separate studies. The objective of the first study was to assess whether surface coal mines in the forested central Appalachian regions of the US can be separated from the other prevalent forest-replacing disturbances through analysis of an interannual chronosequence of Landsat images. Disturbances were classified using descriptors of the disturbance/recovery trajectories: disturbance minimum, recovery slope and recovery maximum. Three vegetation indices (VIs) (normalized difference vegetation index, NDVI; tasseled cap greenness/brightness ratio, TC G/B; and inverse of Landsat band 3, B3I) were used to analyze multitemporal trajectories generated using both pixels and objects. Classification accuracies using objects were better than those obtained using pixels for all VIs. The highest object-based classification accuracy was achieved using TC G/B (89%), followed by NDVI (88%) and B3I (80%). The objective of the second study was to evaluate performance of a woody canopy cover (including both native and invasive species) estimation method based on the 2011 National Land Cover Database (NLCD) protocol for both mined and non-mined areas of the central Appalachians. Potential explanatory variables included raw and derived bands from leaf-on and leaf-off Landsat scenes plus terrain descriptors. Results show that the model developed to estimate canopy cover for mines (R2 = 0.78, Adj. R2 = 0.77, RMSE = 16%) is more robust than the models developed for non-mines, mixed, and all areas combined. The objective of the third study was to determine whether four disturbance/recovery parameters (recovery time, disturbance minimum, recovery slope, and recovery maximum), alone or in combination with variables identified in the second study, enable robust estimation of woody canopy cover on reclaimed surface coal mines. Of the disturbance/recovery parameters, only recovery time made a significant contribution to the model (R2 0.45, Adj. R2 0.44, RMSE 14%). Addition of leaf-on and leaf-off NDVI improved the R2 to 0.54 (Adj. R2 0.53, RMSE 13%). Analysis of Landsat data has strong potential for identifying reclaimed mines and characterizing the extent to which woody canopy has recovered post-reclamation. / Ph. D.

In den letzten 30-40 Jahren hat sich das arktische Klimasystem dramatisch verändert. Phänomene wie der schnelle Rückgang des arktischen Meereises und die beschleunigte Zunahme der oberflächennahen Lufttemperaturen sind wesentliche Kennzeichen der arktischen Verstärkung des Klimawandels, verursacht durch verschiedene Rückkopplungsmechanismen. Der polwärts gerichtete Transport latenter Wärme, hauptsächlich durch Warmlufteinschübe (WLE), hat deutlich zugenommen. In entgegengesetzter Richtung bezeichnen marine Kaltluftausbrüche (KLA) den südwärts gerichteten Transport kalter und trockener arktischer Luftmassen. Sowohl WLE als auch KLA haben große Auswirkungen auf das arktische Klimasystem, doch ihre begleitenden Luftmassentransformationen sind noch nicht vollständig verstanden und quantifiziert. Um diese Lücke zu schließen, kombiniert diese kumulative Dissertation neuartige Lagrange’sche (Luftmassen-folgende) Trajektoranalysen mit atmosphärischen Reanalysen und Beobachtungen von drei kürzlich durchgeführten arktischen Expeditionen. In Paper I (Kirbus et al., 2023a) wird ein WLE Mitte April 2020 analysiert. Messungen der Expedition Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) zeigen einen raschen Anstieg der 2-m Lufttemperatur um etwa 30K in zwei Tagen und einen anomalen Erwärmungseffekt auf das Energiebudget der Oberfläche. In einem neuen methodischen Ansatz wird die Entwicklung nahezu aller Luftmassen, welche über MOSAiC enden, sowie die relevanten Prozesse und Luftmassentransformationen ausgewertet. Für Paper II (Kirbus et al., 2023b) wird ein komplexer KLA im Herbst 2020 erforscht. Die gleiche Luftmasse wurde zuerst in der Zentralarktis durch MOSAiC und zwei Tage später in der eisfreien Framstraße durch die Kampagne MOSAiC Airborne observations in the Central Arctic (MOSAiC-ACA) beobachtet. Eine atmosphärische Reanalyse wird genutzt, um die zeitliche Entwicklung der Luftmasse nachzuvollziehen. Darüber hinaus werden Temperatur- und Feuchtetendenzen genutzt, um die Luftmassentransformationen während des Drifts zu untersuchen. Entgegen der Erwartung werden diese Transformationen nicht nur durch Oberflächenveränderungen (Meereis zu offenem Ozean) beeinflusst, sondern auch durch differentielle Advektion von Wolken und Wasserdampf. Die Bedeutung von Windscherung und vertikaler Interaktionen wird hervorgehoben. Paper III (Kirbus et al., 2024a) untersucht einen intensiven KLA während der HALO-(AC)³-Kampagne im Frühjahr 2022. Die praktizierte quasi-Lagrange’sche Flugstrategie erlaubt die Quantifizierung der diabatischen Erwärmung, Feuchteaufnahme und gleichzeitigen Wolkenentwicklung entlang des KLA. Durch den Vergleich von zwei Reanalysenprodukten mit den Beobachtungen werden Herausforderungen bei der Darstellung der Randeiszone, des turbulenten Wärmeflusses, sowie von Wolken- und Niederschlagsbildung aufgedeckt. Abschließend wird die quasi-Lagrange’sche Auswertung auf die gesamte HALO-(AC)³-Kampagne ausgedehnt, was zu einem umfangreichen Datensatz von mehrfach beobachteten Luftmassen führt (Kirbus et al., 2024b,c). Ergebnisse aus Paper IV (Wendisch et al., 2024) geben einen statistischen Überblick über diese quasi-Lagrange’schen matches, sowie über diabatische Erwärmung/Abkühlung und Feuchtigkeitsänderungen innerhalb arktischer WLE und KLA.:Overview of Research Articles by Benjamin Kirbus Contributions of Benjamin Kirbus to Papers I-IV Supervision Statement 1 Air Mass Transformations in a Changing Arctic Climate System 1.1 Arctic Amplification 1.1.1 Arctic Climate Changes 1.1.2 Feedback Mechanisms 1.1.3 Role of Meridional Transport 1.2 Warm and Moist Air Intrusions 1.3 Marine Cold Air Outbreaks 1.4 Research Questions 2 Methods 2.1 Observations 2.1.1 Shipborne Measurements 2.1.2 Airborne Measurements 2.2 Trajectory Calculations 2.2.1 Eulerian versus Lagrangian Viewpoints 2.2.2 Trajectory Models 2.2.3 Challenges and Mitigation Strategies 2.3 Reanalysis Data 2.3.1 ERA5 2.3.2 CARRA 3 Results 3.1 Paper I – Pathways and Governing Processes of an Arctic WAI Observed During MOSAiC 3.1.1 Motivation and Methods 3.1.2 Impacts at the MOSAiC Site 3.1.3 Investigation of Air Mass Pathways 3.2 Paper II – An Autumn CAO Forced by Surface Changes and Vertical Interactions Through Advection in Higher Altitudes 3.2.1 Motivation and Methods 3.2.2 Thermodynamic and Cloud Evolution 3.2.3 Investigation of the Transformation Processes and Vertical Interactions 3.3 Paper III – Quasi-Lagrangian Thermodynamic and Cloud Evolution From Observations Compared to Reanalyses 3.3.1 Motivation and Methods 3.3.2 Spatial Overview and Thermodynamic Profiles 3.3.3 Diabatic Heating and Moistening 3.4 Paper IV – Observed Diabatic Heating/Cooling and Moisture Changes During All WAIs and CAOs of HALO-(AC)³ 3.4.1 Motivation and Methods 3.4.2 Statistics on Matching Trajectories 3.4.3 Diabatic Heating/Cooling and Moisture Changes in WAIs and CAOs 4 Summary and Outlook References List of Abbreviations List of Symbols List of Figures List of Tables Acknowledgments Curriculum Vitae Appendix A: Paper I Appendix B: Paper II Appendix C: Paper III Appendix D: Paper IV / In the last 30-40 years, the Arctic climate system has undergone dramatic changes. Phenomena like the rapid decline of Arctic sea ice and enhanced increase of near-surface air temperatures compared to the globe are key signatures of the Arctic amplification of climate change, caused by various local and remote feedback mechanisms. Poleward transport of latent heat, primarily through episodic warm and moist air intrusions (WAIs), has increased considerably. In opposite direction, marine cold air outbreaks (CAOs) denote the southward transport of cold and dry Arctic air masses. Both WAIs and CAOs have large impacts on the Arctic climate system, yet their accompanying air mass transformations are not fully understood and quantified. To investigate the mechanisms shaping WAIs and CAOs, this cumulative dissertation combines novel Lagrangian (air mass following) trajectory analysis with atmospheric reanalyses and observations from three recent Arctic expeditions. In Paper I (Kirbus et al., 2023a), an intense WAI occurring in mid-April 2020 is analyzed. Measurements from the Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition show a rapid rise of the 2-m air temperature by about 30K within two days, and an anomalous heating effect on the surface energy budget (SEB). A novel methodological approach is developed to investigate the air mass pathways during the WAI, tracing the evolution and transformation mechanisms of virtually all air masses ending above the MOSAiC site. The impact of the WAI on the SEB is investigated based on reanalysis data and observations both during the poleward drift, as well as at the MOSAiC site. For Paper II (Kirbus et al., 2023b), a complex CAO occurring in autumn 2020 is explored, where the same air mass was first observed in the central Arctic during MOSAiC, and then two days later over the ice-free waters of Fram Strait as part of the MOSAiC Airborne observations in the Central Arctic (MOSAiC-ACA) campaign. The temporal evolution of the air mass is traced using reanalysis output, while reanalysis-derived temperature and humidity tendencies are utilized to explore the air mass transformations along the pathway. Contrary to expectations, the air mass transformations are not solely driven by surface changes from sea ice to open ocean, but also impacted by differential advection of clouds and water vapor across the near-surface flow. The relevance of wind shear and vertical interactions is therefore highlighted. Paper III (Kirbus et al., 2024a) investigates a strong Arctic CAO observed during the HALO-(AC)³ campaign in spring 2022. For the first time, airborne observations gathered using a dedicated quasi-Lagrangian flight strategy enable a quantification of diabatic heating, moisture uptake, and concurrent cloud evolution along a CAO. By confronting two reanalysis products with the observations, their challenges with representing the marginal sea-ice zone, surface turbulent heat fluxes, clouds, and precipitation are revealed. Finally, the quasi-Lagrangian analysis is extended to the whole HALO-(AC)³ campaign, resulting in a large dataset of matching air masses (Kirbus et al., 2024b,c). Paper IV (Wendisch et al., 2024) provides a statistical overview of these quasi-Lagrangian matches, as well as of diabatic heating/cooling and moisture changes within Arctic WAIs and CAOs.:Overview of Research Articles by Benjamin Kirbus Contributions of Benjamin Kirbus to Papers I-IV Supervision Statement 1 Air Mass Transformations in a Changing Arctic Climate System 1.1 Arctic Amplification 1.1.1 Arctic Climate Changes 1.1.2 Feedback Mechanisms 1.1.3 Role of Meridional Transport 1.2 Warm and Moist Air Intrusions 1.3 Marine Cold Air Outbreaks 1.4 Research Questions 2 Methods 2.1 Observations 2.1.1 Shipborne Measurements 2.1.2 Airborne Measurements 2.2 Trajectory Calculations 2.2.1 Eulerian versus Lagrangian Viewpoints 2.2.2 Trajectory Models 2.2.3 Challenges and Mitigation Strategies 2.3 Reanalysis Data 2.3.1 ERA5 2.3.2 CARRA 3 Results 3.1 Paper I – Pathways and Governing Processes of an Arctic WAI Observed During MOSAiC 3.1.1 Motivation and Methods 3.1.2 Impacts at the MOSAiC Site 3.1.3 Investigation of Air Mass Pathways 3.2 Paper II – An Autumn CAO Forced by Surface Changes and Vertical Interactions Through Advection in Higher Altitudes 3.2.1 Motivation and Methods 3.2.2 Thermodynamic and Cloud Evolution 3.2.3 Investigation of the Transformation Processes and Vertical Interactions 3.3 Paper III – Quasi-Lagrangian Thermodynamic and Cloud Evolution From Observations Compared to Reanalyses 3.3.1 Motivation and Methods 3.3.2 Spatial Overview and Thermodynamic Profiles 3.3.3 Diabatic Heating and Moistening 3.4 Paper IV – Observed Diabatic Heating/Cooling and Moisture Changes During All WAIs and CAOs of HALO-(AC)³ 3.4.1 Motivation and Methods 3.4.2 Statistics on Matching Trajectories 3.4.3 Diabatic Heating/Cooling and Moisture Changes in WAIs and CAOs 4 Summary and Outlook References List of Abbreviations List of Symbols List of Figures List of Tables Acknowledgments Curriculum Vitae Appendix A: Paper I Appendix B: Paper II Appendix C: Paper III Appendix D: Paper IV

Cross median crashes have become a serious problem in recent years. Most of the median cross sections used for divided highways have terrains with steep slopes. Traffic barriers, frequently used on slopes, are generally designed based on the findings obtained from crash tests performed on flat terrain. For barriers placed on roadside and median slopes, vehicle impact height varies depending on the trajectory of the vehicle along the ditch section and lateral offset of the barrier. Thus depending on the placement location on a relatively steep slope, a barrier can be impacted by an errant vehicle at height and orientation more critical compared to those considered during its design. Hence, detailed study of performance of barriers on roadside and median slopes is needed to achieve acceptable safety performance. In this study, performances of modified G4(1S) W-beam, Midwest Guardrail System (MGS), modified Thrie-beam, modified weak post W-beam, and box-beam guardrail systems on sloped terrains are investigated using numerical simulations. A procedure is developed that provide guidance for their placement on roadside and median slopes. The research approach consists of nonlinear finite element analyses and multi-rigid-body dynamic analyses approach. Detailed finite element representation for each of the barriers is developed using LS-DYNA. Model fidelity is assessed through comparison of simulated and measured responses reported in full scale crash test studies conducted on flat terrain. LS-DYNA simulations of vehicle impacts on barriers placed on flat terrain at different impact heights are performed to identify performance limits of the barriers in terms of acceptable vehicle impact heights. The performances of the barriers are evaluated following the guidelines provided in NCHRP Report 350. Multi-rigid-body dynamic analysis code, CARSIM, is used to identify trajectories of the vehicles traversing various roadside and median cross-slopes. After analyzing vehicle trajectories and barrier performance limits, a guideline has been prepared with recommendations for the placement of barriers along roadside and median slopes. This guideline is then verified and refined using the responses obtained from full-scale LS-DYNA simulations. These simulations capture the full encroachment event from departure of the vehicle off the traveled way through impact with the barrier.

A key proposition of Gottfredson and Hirschi's (1990) self-control theory is the stability hypothesis which suggests that an individual's level of self-control, once established between the ages of 8-10, is stable over the life course. Empirical results from examinations of the stability hypothesis have been mixed. Prior tests of the stability hypothesis have employed aggregate assessment methods (e.g., mean-level and correlational analyses). Such approaches fail to take into account the possibility that individual developmental pathways may differ. This study employs individual longitudinal data over a four year period for 3,249 7th to 10th grade subjects to assess the stability hypothesis using both traditional stability estimation techniques (e.g., ANOVAs and zero-order correlations), as well as heterogeneity assessment methods - semiparametric group-based trajectory modeling (SPGM). Multinomial logistic regression (MLOGIT) of theoretically and empirically relevant risk factors (i.e., parenting, parental criminality, deviant peers, bonds to school) was employed to distinguish between developmental trajectories. SPGM results suggest that self-control is stable for a majority of the sample; however, a sizeable portion of the sample evinced trajectories for which self-control was marked by considerable change. Specifically, 6 unique trajectories in the development of self-control were identified - two groups were identified with high stable trajectories of self-control and four groups were identified that had lower, less stable trajectories of self-control. Additionally, several risk factors differentiated these groups. The results indicate that those with lower, less stable trajectories have more deviant peer association, higher rates of parental criminality, less intense bonds to school, and lower levels of parenting. These results indicate that self control is not stable nor is it consistent across groups, leading to a rejection of Hirschi and Gottfredson's explanation.

L'objectif principal de ce travail de thèse est d'améliorer la prise en compte des peuplements de taillis dans les logiciels d'analyse trajectographique.Dans un premier temps, un modèle numérique permettant de créer des peuplements virtuels de taillis à l'échelle du versant a été développé et validé sur la base d'inventaires forestiers réalisés dans des taillis.Deux modèles numériques permettant de simuler des impacts de blocs sur des franc pieds et des cépées ont été également développés en utilisant la Méthode des Éléments Discrets (MED).Ces modèles ont été calibrés par des essais d'impact sur des tiges de hêtre.Ils permettent d'intégrer l'influence du houppier et du système racinaire, de modéliser explicitement le contact entre le bloc et les tiges impactées, et d'intégrer les non-linéarités matérielles (rupture des tiges, délaminage) se développant dans le tronc au cours de l'impact.Ces travaux ont conduit à la construction d'un modèle trajectographique MED permettant de simuler la propagation d'un bloc dans une forêt de taillis à l'échelle du versant. Finalement, le rôle protecteur de différents peuplements de taillis contre l'aléa de chute de bloc a été caractérisé à l'aide de ce modèle. / This research work is dedicated to improve the integration of coppice stands in rockfall analyses.First, a model was built to create virtual coppice stands. This model was validated using field inventories in coppice stands.Two numerical models were developed to simulate impacts of blocks on single trees and coppice stools using the Discrete Elements Method (MED).These models were calibrated using laboratory impact tests on beech stems.They account for the influence of the root system and of the crown on the tree dynamic response, the explicit modeling of the contact between the block and the impacted stem and the non-linearity evolution into the trunk during impact.Finally, a DEM rockfall software was developed to model rockfall propagation in coppice stands.The protective role against rockfall hazard of different coppice stands was characterized with this model.