Background: According to current guidelines the cost of productivity loss should be considered in pharmacoeconomic analyses. The cost of health-related productivity loss in psoriasis patients is unknown. Objective: To estimate the cost of productivity loss in psoriasis and its association with health-related quality of life and clinical disease severity. Methods: Cross-sectional study, recruitment of adult participants through Internet advertisements. 201 (72.3%) out of 278 eligible participants completed the study. Health-related work productivity loss, quality of life and clinical severity of psoriasis were assessed by standardized instruments. Results: Indirect costs of productivity loss clearly exceed the total direct cost. In contrast to objective clinical disease severity, health-related quality of life (measured by the Dermatology Life Quality Index) is an independent predictor of work productivity. Conclusions: There is good reason to believe that intervention can reduce health-related productivity loss by improving patients’ quality of life. Savings from increased work productivity might offset comparatively high acquisition costs of biological agents. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Chronic plaque-type psoriasis is a major dermatosis, but a significant question is still unanswered: What defines severity in chronic plaque-type psoriasis? While objective assessments like the Psoriasis Area and Severity Index (PASI) have frequently been used in clinical trials, quality of life (QOL) questionnaires are currently becoming more and more popular. Objective: This article summarizes the most important objective and subjective measurements of severity in psoriasis. For every dermatologist it is critically important to distinguish between severe psoriasis and psoriasis that severely affects QOL. Even if the PASI also has disadvantages, it is the most adequate instrument available to evaluate severity in plaque-type psoriasis. Result: We provide reasons why PASI >12 defines severe, PASI 7–12 moderate and PASI <7 mild chronic plaque-type psoriasis. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Chronic plaque-type psoriasis is a major dermatosis, but a significant question is still unanswered: What defines severity in chronic plaque-type psoriasis? While objective assessments like the Psoriasis Area and Severity Index (PASI) have frequently been used in clinical trials, quality of life (QOL) questionnaires are currently becoming more and more popular. Objective: This article summarizes the most important objective and subjective measurements of severity in psoriasis. For every dermatologist it is critically important to distinguish between severe psoriasis and psoriasis that severely affects QOL. Even if the PASI also has disadvantages, it is the most adequate instrument available to evaluate severity in plaque-type psoriasis. Result: We provide reasons why PASI >12 defines severe, PASI 7–12 moderate and PASI <7 mild chronic plaque-type psoriasis. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: According to current guidelines the cost of productivity loss should be considered in pharmacoeconomic analyses. The cost of health-related productivity loss in psoriasis patients is unknown. Objective: To estimate the cost of productivity loss in psoriasis and its association with health-related quality of life and clinical disease severity. Methods: Cross-sectional study, recruitment of adult participants through Internet advertisements. 201 (72.3%) out of 278 eligible participants completed the study. Health-related work productivity loss, quality of life and clinical severity of psoriasis were assessed by standardized instruments. Results: Indirect costs of productivity loss clearly exceed the total direct cost. In contrast to objective clinical disease severity, health-related quality of life (measured by the Dermatology Life Quality Index) is an independent predictor of work productivity. Conclusions: There is good reason to believe that intervention can reduce health-related productivity loss by improving patients’ quality of life. Savings from increased work productivity might offset comparatively high acquisition costs of biological agents. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Standards define target reliability levels that govern the safety of designed structures. These target levels should be around an economic optimum for the class of structure under consideration. However, society may have safety requirements in excess of that required to achieve an economic optimum. The LQI criterion can be used to determine society’s willingness to invest in safety, thereby defining a minimum acceptable safety- or reliability level. This thesis determines economically optimised reliability levels for reliability class two concrete structures in South Africa, over a range of typical input parameters. Rackwitz’s (2000) approach is used here, adjusted for the South African context. The structure is described using a simple limit state function, defined as the difference between load and resistance, with resistance a function of a global safety parameter. South African construction costs, costs of increasing safety, failure costs and discount rates are used in the objective function for economic optimisation. Life Quality Index (LQI) theory is used as a basis to derive society’s willingness to pay (SWTP) for safety and the corresponding reliability level is found by applying the LQI criterion. In the South African context the derivation of SWTP presents some challenges, which is discussed. Situations where the minimum required reliability would exceed the economically optimum reliability level are discussed. Various reliability based cost optimization case studies are conducted covering a broad range of typical concrete design situations. From these case studies a range of target reliability indices are derived for typical concrete structural components and failure modes. Obtained values are compared to current South African target levels of reliability provided by the South African loading code and recommendations are made. The approach used by Rackwitz (2000) is compared with results obtained from case studies and used as basis to estimate optimum reliability levels for other types of buildings. Functions are written in MATLAB to allow replication of the study for others seeking to derive optimum reliability indices. / AFRIKAANSE OPSOMMING: Standaarde spesifiseer teiken betroubaarheidsvlakke wat die veiligheidsvlak van ontwerpte strukture bepaal. Hierdie teikenvlak moet rondom die ekonomiese optimum wees vir die klas van struktuur onder oorweging. Die samelewing verkies moontlik ‘n hoër veiligheidsvlak as wat deur die ekonomiese optimum dikteer word. Die LKI (Lewens Kwaliteit Indeks) maatstaf kan gebuik word om die samelewing se bereidwilligheid om in veiligheid te belê te bepaal en sodoende ‘n minimum veiligheidsvlak bepaal. Hierdie tesis bepaal die ekonomiese optimum betroubaarheidsvlak vir klas twee beton strukture in Suid-Afrika vir wisselende parameters. Rackwitz (2000) se benadering word in hierdie studie gebruik en is aangepas vir Suid-Afrikaanse omstandighede. Die struktuur word beskryf deur ‘n eenvoudige limiet staat funksie, gedefinieer as die verskil tussen die las en weerstand, met die weerstand as die funksie van ‘n globale veiligheidsparameter. Suid-Afrikaanse konstruksie koste, veiligheidsvermedering koste, falingskoste en diskonteer koerse word gebruik vir optimering. Die LKI teorie word gebruik om SBB (Samelewing Bereidheid om te Belê) vir veiligheid af te lei en die ooreenkomstige betroubaarheidsvlak word bepaal deur die LKI maatstaf toe te pas. In die afleiding hiervan vir Suid-Afrikaanse omstandighede is sekere uitdagings teegekom wat bespreek word. Situasies waar die minimum betroubaarheidsvlak hoer is as die ekonomiese optimum word bespreek. Verskillende betroubaarheids gebaseerde optimering gevalstudies word gedoen op tipiese beton struktuur elemente. Van hierdie gevalstudies is optimum betroubaarheidsindekse vir die tipiese beton elemente en galingsmodusie afgelei. Die betroubaarheidsindekse word vergelyk met huidige betroubaarheidsindekse soos wat voorgeskryf is in die Suid-Afrikaanse laskode (SANS10160-1(2011)). Rackwitz (2000) se benadering word vergelyk met die resultate van die gevallestudies en word gebruik as basis om optimum betroubaarheidsvlakke vir ander tipes geboue te voorspel. MATLAB funksies is geprogrameer om minimum en optimum betroubaarheidsindekse af te lei.

For railways, risk analysis is carried out to identify hazardous situations and their consequences. Until recently, classical methods such as Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) were applied in modelling the linear and logically deterministic aspects of railway risks, safety and reliability. However, it has been proven that modern railway systems are rather complex, involving multi-dependencies between system variables and uncertainties about these dependencies. For train derailment accidents, for instance, high train speed is a common cause of failure; slip and failure of brake applications are disjoint events; failure dependency exists between the train protection and warning system and driver errors; driver errors are time dependent and there is functional uncertainty in derailment conditions. Failing to incorporate these aspects of a complex system leads to wrong estimations of the risks and safety, and, consequently, to wrong management decisions. Furthermore, a complex railway system integrates various technologies and is operated in an environment where the behaviour and failure modes of the system are difficult to model using probabilistic techniques. Modelling and quantification of the railway risk and safety problems that involve dependencies and uncertainties such as mentioned above are complex tasks. Importance measures are useful in the ranking of components, which are significant with respect to the risk, safety and reliability of a railway system. The computation of importance measures using FTA has limitation for complex railways. ALARP (As Low as Reasonably Possible) risk acceptance criteria are widely accepted as ’\'best practice’’ in the railways. According to the ALARP approach, a tolerable region exists between the regions of intolerable and negligible risks. In the tolerable region, risk is undertaken only if a benefit is desired. In this case, one needs to have additional criteria to identify the socio-economic benefits of adopting a safety measure for railway facilities. The Life Quality Index (LQI) is a rational way of establishing a relation between the financial resources utilized to improve the safety of an engineering system and the potential fatalities that can be avoided by safety improvement. This thesis shows the application of the LQI approach to quantifying the social benefits of a number of safety management plans for a railway facility. We apply Bayesian Networks and influence diagrams, which are extensions of Bayesian Networks, to model and assess the life safety risks associated with railways. Bayesian Networks are directed acyclic probabilistic graphical models that handle the joint distribution of random variables in a compact and flexible way. In influence diagrams, problems of probabilistic inference and decision making – based on utility functions – can be combined and optimized, especially, for systems with many dependencies and uncertainties. The optimal decision, which maximizes the total benefits to society, is obtained. In this thesis, the application of Bayesian Networks to the railway industry is investigated for the purpose of improving modelling and the analysis of risk, safety and reliability in railways. One example application and two real world applications are presented to show the usefulness and suitability of the Bayesian Networks for the quantitative risk assessment and risk-based decision support in reference to railways.

Background: Financial constraints challenge evidence of the effectiveness of dermatological inpatient management. Objective: To evaluate the effectiveness of hospitalization in atopic dermatitis and psoriasis regarding initial and sustained benefits. Methods: Prospective study on adults with psoriasis vulgaris (n = 22) and atopic dermatitis (n = 14). At admission, discharge, and 3 months after discharge, validated outcomes of objective and subjective disease severity were assessed by trained investigators. Results: Hospitalization resulted in substantial benefit in quality of life and clinical disease severity. Looking at mean scores, the observed benefit appeared stable until 3-month follow-up. The analysis of individual patient data revealed significant changes in disease severity between discharge and 3-month follow-up with some patients relapsing, others further improving. Reasons for hospitalization and treatment performed were not related to sustained benefit. Conclusions: In psoriasis vulgaris and atopic dermatitis, hospitalization effectively improved quality of life and clinical disease severity. Further research should focus on prognostic factors for sustained improvement. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

Background: Financial constraints challenge evidence of the effectiveness of dermatological inpatient management. Objective: To evaluate the effectiveness of hospitalization in atopic dermatitis and psoriasis regarding initial and sustained benefits. Methods: Prospective study on adults with psoriasis vulgaris (n = 22) and atopic dermatitis (n = 14). At admission, discharge, and 3 months after discharge, validated outcomes of objective and subjective disease severity were assessed by trained investigators. Results: Hospitalization resulted in substantial benefit in quality of life and clinical disease severity. Looking at mean scores, the observed benefit appeared stable until 3-month follow-up. The analysis of individual patient data revealed significant changes in disease severity between discharge and 3-month follow-up with some patients relapsing, others further improving. Reasons for hospitalization and treatment performed were not related to sustained benefit. Conclusions: In psoriasis vulgaris and atopic dermatitis, hospitalization effectively improved quality of life and clinical disease severity. Further research should focus on prognostic factors for sustained improvement. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.

This work aims to give a contribution to studies about employment quality and workforce life conditions of people living in the rural megaregions of Minas Gerais, specially the paid employee. The focus will be the megaregions of Minas Gerais, distinguished by more and less modernization, in the cultivation of coffee, sugar cane and corn, considering both agricultural employees and families. Taking into consideration the decrease of agricultural employment occurred in the 2000 s and the growth of non-agricultural activities, giving rise to the New Ruralism and the new forms of occupation for the paid job outside agriculture, a comparative analyzes of job quality and life conditions for the non- and agricultural employees will be made. The analyzes will indicate if the non-agricultural employment (ERNAs) leads to a better quality of employment and life conditions, when compared to agricultural one. The results obtained in this work indicate a better level of quality in the agricultural employment for the employees living in the more modernized megaregions and with city residence; the conditions are worse for the employees with rural residence working in the less modernized megaregions. Agricultural employee life conditions were clearly better for those living in the city and worse for those living in the rural area. In this sense, for the agricultural families and employees the rural environment continues to reproduce more precarious conditions in relation to the job, mainly in the poorer megaregions. On the other hand, for non-agricultural employees, job quality index was better than for those agricultural, with the exception of qualified employees living in the rural area of megaregion TMAP and Northwest of Minas Gerais. However, the quality of non-agricultural employment was better for more traditional activities, such as those performed in the more modernized megaregions industries, and it was worse for more precarious activities such as paid domestic work (SDR) in the less modernized megaregions. Life conditions were revealed better for all non-agricultural activities, when compared to the agricultural ones, occurring improvement in all selected activities and showing evolution in the mentioned decade. However, those conditions were worse in the less modernized megaregions, and in terms of number, these regions received the largest number of non-agricultural employees. Even presenting better life conditions, the non-agricultural employees are concentrated in the poorer megaregions and in more precarious activities such as paid domestic work (SDR). In conclusion, more than delve into the study of the impacts of modernization in the paid job in Minas Gerais, this work aims to reveal if working conditions (measured by IQE) and families life conditions (measured by ICV) in the rural area implied improvement for non-agricultural employment in comparison with agricultural employment, and if these changes implied in bigger rural development or if it emphasized more the inequalities in rural areas in Minas Gerais. In this investigation the data from the IBGE 2000 and 2010 Demographic Census were used, in the construction of the IQE and ICV indexes, based on the Balsadi (2005) methodology; for the definition of megaregions more and less modernized the data from Censo Agropecuário and PAM were used. / Este trabalho tem como objetivo contribuir com os estudos em torno da qualidade do emprego e condições de vida da força de trabalho residente no setor rural das Mesorregiões de Minas Gerais, especificamente, o empregado assalariado. O recorte compreende as Mesorregiões de Minas Gerais, separadas por mais e menos modernizadas nas culturas do café, cana-de-açúcar e milho, envolvendo os empregados e as famílias agrícolas. Considerando a queda dos empregos agrícolas ocorridos na década estudada e o crescimento das atividades não agrícolas, considerando o novo rural e as novas formas de ocupação para o emprego assalariado fora da agricultura, será realizada também uma análise comparativa da qualidade do emprego e as condições de vida oferecidas a esses empregados agrícolas e não agrícolas, destacando, a partir dos resultados, se os empregos rurais não agrícolas (ERNAs) se consubstanciaram em maior qualidade do emprego e condições de vida quando comparados aos agrícolas. Os resultados obtidos na tese apontam para uma maior qualidade do emprego agrícola para os empregados nas Mesorregiões mais modernizadas, mas com residência urbana, sendo piores para os empregados com domicilio rural e presentes nas Mesorregiões menos modernizadas. As condições de vida dos empregados agrícolas também foram nitidamente melhores para os empregados com domicílio urbano e piores para aqueles com domicilio rural. Nesse sentido, para os empregados e famílias dos empregados agrícolas, o setor rural continua reproduzindo condições mais precárias em relação ao emprego, principalmente, nas Mesorregiões mais pobres. Já para os empregados das atividades não agrícolas, a qualidade do emprego foi melhor que para os agrícolas, com exceção dos empregados qualificados e com domicílio rural na Mesorregião TMAP e Noroeste de Minas. Entretanto, a qualidade do emprego não agrícola foi melhor para as atividades mais tradicionais, como a indústria das Mesorregiões mais modernizadas, e pior para as atividades mais precárias, como serviços domésticos remunerados (SDR), por exemplo, nas Mesorregiões menos modernizadas. As condições de vida se mostraram mais elevadas para todas as atividades não agrícolas, quando comparadas às agrícolas, ocorrendo melhora em todas as atividades selecionadas, o que representa uma evolução na década, continuando, porém, sendo piores para as Mesorregiões menos modernizadas e que, em volume, absorveram o maior número de empregados não agrícolas. Assim, mesmo apresentando condições de vida melhores, os assalariados não agrícolas estão concentrados em maior número nas Mesorregiões mais pobres e nas atividades mais precárias como, principalmente, nos SDR, e serviços. Em síntese, mais que aprofundar o estudo dos impactos da modernização no emprego assalariado de Minas Gerais, este trabalho busca evidenciar se as condições de trabalho (medido pelo IQE) e condições de vida das famílias (medido pelo ICV) no meio rural significaram melhoras para os empregos não agrícolas, em comparação aos agrícolas, e se essas mudanças implicaram em maior desenvolvimento rural ou se acentuaram ainda mais as desigualdades no meio rural mineiro. Foram utilizados na investigação os dados do Censo Demográfico de 2000 e 2010 do IBGE, para a construção dos índices do IQE e do ICV, fundamentados na metodologia de Balsadi (2005), e o Censo Agropecuário e PAM, para a definição das Mesorregiões mais e menos modernizadas. / Doutor em Economia

For railways, risk analysis is carried out to identify hazardous situations and their consequences. Until recently, classical methods such as Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) were applied in modelling the linear and logically deterministic aspects of railway risks, safety and reliability. However, it has been proven that modern railway systems are rather complex, involving multi-dependencies between system variables and uncertainties about these dependencies. For train derailment accidents, for instance, high train speed is a common cause of failure; slip and failure of brake applications are disjoint events; failure dependency exists between the train protection and warning system and driver errors; driver errors are time dependent and there is functional uncertainty in derailment conditions. Failing to incorporate these aspects of a complex system leads to wrong estimations of the risks and safety, and, consequently, to wrong management decisions. Furthermore, a complex railway system integrates various technologies and is operated in an environment where the behaviour and failure modes of the system are difficult to model using probabilistic techniques. Modelling and quantification of the railway risk and safety problems that involve dependencies and uncertainties such as mentioned above are complex tasks. Importance measures are useful in the ranking of components, which are significant with respect to the risk, safety and reliability of a railway system. The computation of importance measures using FTA has limitation for complex railways. ALARP (As Low as Reasonably Possible) risk acceptance criteria are widely accepted as ’\'best practice’’ in the railways. According to the ALARP approach, a tolerable region exists between the regions of intolerable and negligible risks. In the tolerable region, risk is undertaken only if a benefit is desired. In this case, one needs to have additional criteria to identify the socio-economic benefits of adopting a safety measure for railway facilities. The Life Quality Index (LQI) is a rational way of establishing a relation between the financial resources utilized to improve the safety of an engineering system and the potential fatalities that can be avoided by safety improvement. This thesis shows the application of the LQI approach to quantifying the social benefits of a number of safety management plans for a railway facility. We apply Bayesian Networks and influence diagrams, which are extensions of Bayesian Networks, to model and assess the life safety risks associated with railways. Bayesian Networks are directed acyclic probabilistic graphical models that handle the joint distribution of random variables in a compact and flexible way. In influence diagrams, problems of probabilistic inference and decision making – based on utility functions – can be combined and optimized, especially, for systems with many dependencies and uncertainties. The optimal decision, which maximizes the total benefits to society, is obtained. In this thesis, the application of Bayesian Networks to the railway industry is investigated for the purpose of improving modelling and the analysis of risk, safety and reliability in railways. One example application and two real world applications are presented to show the usefulness and suitability of the Bayesian Networks for the quantitative risk assessment and risk-based decision support in reference to railways.:ACKNOWLEDGEMENTS IV ABSTRACT VI ZUSAMMENFASSUNG VIII LIST OF FIGURES XIV LIST OF TABLES XVI CHAPTER 1: Introduction 1 1.1 Need to model and quantify the causes and consequences of hazards on railways 1 1.2 State-of-the art techniques in the railway 2 1.3 Goals and scope of work 4 1.4 Existing work 6 1.5 Outline of the thesis 7 CHAPTER 2: Methods for safety and risk analysis 10 2.1 Introduction 10 2.1.1 Simplified risk analysis 12 2.1.2 Standard risk analysis 12 2.1.3 Model-based risk analysis 12 2.2 Risk Matrix 14 2.2.1 Determine the possible consequences 14 2.2.2 Likelihood of occurrence 15 2.2.3 Risk scoring matrix 15 2.3 Failure Modes & Effect Analysis – FMEA 16 2.3.1 Example application of FMEA 17 2.4 Fault Tree Analysis – FTA 19 2.5 Reliability Block Diagram – RBD 22 2.6 Event Tree Analysis – ETA 24 2.7 Safety Risk Model – SRM 25 2.8 Markov Model – MM 27 2.9 Quantification of expected values 31 2.9.1 Bayesian Analysis – BA 35 2.9.2 Hazard Function – HF 39 2.9.3 Monte Carlo (MC) Simulation 42 2.10 Summary 46 CHAPTER 3: Introduction to Bayesian Networks 48 3.1 Terminology in Bayesian Networks 48 3.2 Construction of Bayesian Networks 49 3.3 Conditional independence in Bayesian Networks 51 3.4 Joint probability distribution in Bayesian Networks 52 3.5 Probabilistic Inference in Bayesian Networks 53 3.6 Probabilistic inference by enumeration 54 3.7 Probabilistic inference by variable elimination 55 3.8 Approximate inference for Bayesian Networks 57 3.9 Dynamic Bayesian Networks 58 3.10 Influence diagrams (IDs) 60 CHAPTER 4: Risk acceptance criteria and safety targets 62 4.1 Introduction 62 4.2 ALARP (As Low As Reasonably Possible) criteria 62 4.3 MEM (Minimum Endogenous Mortality) criterion 63 4.4 MGS (Mindestens Gleiche Sicherheit) criteria 64 4.5 Safety Integrity Levels (SILs) 65 4.6 Importance Measures (IMs) 66 4.7 Life Quality Index (LQI) 68 4.8 Summary 72 CHAPTER 5: Application of Bayesian Networks to complex railways: A study on derailment accidents 73 5.1 Introduction 73 5.2 Fault Tree Analysis for train derailment due to SPAD 74 5.2.1 Computation of importance measures using FTA 75 5.3 Event Tree Analysis (ETA) 78 5.4 Mapping Fault Tree and Event Tree based risk model to Bayesian Networks 79 5.4.1 Computation of importance measures using Bayesian Networks 81 5.5 Risk quantification 82 5.6 Advanced aspects of example application 83 5.6.1 Advanced aspect 1: Common cause failures 83 5.6.2 Advanced aspect 2: Disjoint events 84 5.6.3 Advanced aspect 3: Multistate system and components 84 5.6.4 Advanced aspect 4: Failure dependency 85 5.6.5 Advanced aspect 5: Time dependencies 85 5.6.6 Advanced aspect 6: Functional uncertainty and factual knowledge 85 5.6.7 Advanced aspect 7: Uncertainty in expert knowledge 86 5.6.8 Advanced aspect 8: Simplifications and dependencies in Event Tree Analysis 86 5.7 Implementation of the advanced aspects of the train derailment model using Bayesian Networks. 88 5.8 Results and discussions 92 5.9 Summary 93 CHAPTER 6: Bayesian Networks for risk-informed safety requirements for platform screen doors in railways 94 6.1 Introduction 94 6.2 Components of the risk-informed safety requirement process for Platform Screen Door system in a mega city 97 6.2.1 Define objective and methodology 97 6.2.2 Familiarization of system and information gathering 97 6.2.3 Hazard identification and hazard classification 97 6.2.4 Hazard scenario analysis 98 6.2.5 Probability of occurrence and failure data 99 6.2.6 Quantification of the risks 105 6.2.6.1. Tolerable risks 105 6.2.6.2. Risk exposure 105 6.2.6.3. Risk assessment 106 6.3 Summary 107 CHAPTER 7: Influence diagrams based decision support for railway level crossings 108 7.1 Introduction 108 7.2 Level crossing accidents in railways 109 7.3 A case study of railway level crossing 110 7.4 Characteristics of the railway level crossing under investigation 111 7.5 Life quality index applied to railway level crossing risk problem 115 7.6 Summary 119 CHAPTER 8: Conclusions and outlook 120 8.1 Summary and important contributions 120 8.2 Originality of the work 122 8.3 Outlook 122 BIBLIOGRAPHY 124 APPENDIX 1 131