Background: Dilated Cardiomyopathy (DCM) is the most common functional type of cardiomyopathy in children with significant morbidity and the leading indication for cardiac transplant over 5 years of age. Identification of baseline risk factors for failing medical management by etiologic grouping remain to be elucidated in a large populationbased study. The competing risk for heart death between all-cause mortality and heart transplantation is often overestimated in the literature and may obscure additional novel risk factors associated with poor clinical outcomes. Methods: The National Heart Lung and Blood Institute Pediatric Cardiomyopathy Registry collected longitudinal data from 1731 children with DCM in North America from 1990 to 2007. Composite endpoint (CEP) was the earlier occurrence of death or heart transplant. Univariate and multivariate predictors were identified from demographic and echocardiographic data (expressed as z-scores) collected within 30 days of diagnosis. A competing risk analysis was performed calculating cumulative incidence and identifying novel prognostic factors. All analyses were performed by etiologic group. Results: Multivariate Cox regression identified the highest mortality risk among children with idiopathic disease (N=1192, CEP: 41%) when diagnosed over age 6 years, and with congestive heart failure (CHF) and decreased left ventricular fractional shortening (FS). Risk factors for those with myocarditis (N=272, CEP: 26%) were older age, CHF, and increased left ventricular (LV) end-diastolic dimension (EDD); while for neuromuscular disease (N=139, CEP: 40%), it was a decreased FS and increased EDD. Only univariate predictors were identified for children with familial isolated cardiomyopathy (N=79, CEP: 44%) including: CHF, increased EDD, end-systolic dimension, or LV mass, and decreased FS or ejection fraction), while for children with inborn errors of metabolism (N=43, CEP: 33%) risk factors included: a positive family history of cardiomyopathy or genetic syndromes. The group of children with malformation syndromes (N=6, CEP: 50%) was not large enough to model. Comparison of cause-specific event rates between Kaplan-Meier and cumulative incidence demonstrated an overestimation with the former method. Competing risk multivariate regression showed similar models to those for CEP, with the following exceptions: for neuromuscular disease, an increased EDD had a larger hazard ratio for transplant than for death; for idiopathic disease, an increased EDD was associated with transplant, but not with death, and growth retardation (height-for-age zscore) was associated with death but not transplant. Conclusions: Within etiologic grouping, demographics and echocardiographic values at diagnosis have varying predictive value. Generally, the presence of symptomatic disease in the form of CHF, echocardiographic evidence of more severe DCM, and increased age were indicative of worse outcomes. These results help to validate those from conflicting studies; however, they suggest that etiology modifies the importance of particular factors. Analysis of competing risk provides an alternate interpretation of studies with composite endpoints and assists in the transfer of clinically relevant information. For children with idiopathic and neuromuscular disease, the degree of dilation had a differential effect that has gone unrecognized. The novel finding of reduced stature and its effect on mortality suggests a potential for treatment and mitigation of poor outcomes in idiopathic DCM. Both increased dilation and reduced stature could be used to improve the triage process and refer children to cardiac transplantation who otherwise might die prematurely and unnecessarily. Subsequent studies on the utility of these factors and their effect on improving survival are warranted.

A risk review of a fuel cell-based distributed co-generation (FC-Based DCG) system was conducted to identify and quantify the major technological system risks in a worst-case scenario. A risk review entails both a risk assessment and a risk analysis of a designed system, and it is part of risk engineering. Thorough literature reviews and expert interviews were conducted in the field of fuel cells. A thorough literature review of the risk engineering field was also conducted. A procedure for a risk review of the FC-Based DCG System was developed. The representative system design was identified by the current DCG design technology. The risk assessment was carried out, identifying the system components and potential failure modes and consequences. Then, using probabilities of failure for the various system components, the risk associated with a particular system design was determined. A Monte Carlo simulation on the total system reliability was used to evaluate the potential for system failure at a time of 1 hour, 5 hours, 10 hours, 50 hours, 100 hours and 500 hours of continuous operation. The original system was found to be acceptable at the initial times, but after 100 hours was predicted to fail. The components which consistently contribute significantly to the overall system risk are the membrane electrode assembly (MEA) and the nickel-metal foam flow fields. A revised system was analyzed with the reliability of the MEA and the Ni-foam set to 100%. After the revision, the components which contributed significantly to the system risk were the pumps. Simulations were run for several alternative systems to provide feedback on risk management suggestions. The risk engineering process developed with the design approach for this research is applicable to any system and it accommodates the use of many different risk engineering tools.

This paper makes an analysis of risk and risk management of Swedish cod fishery in the Baltic Sea. The purpose is to describe differences in risk perception between fishery stakeholders and the consequences these imply for political decisions. A literature study was undertaken at the startup-phase to give the study a valid background and interviews with four actors in the fishing industry was conducted. The chosen actors are: The Federation of Swedish Fishermen (SFR), Swedish Board of Fisheries, WWF and one researcher. The results indicate two causes for the cods’ positive trend, good natural conditions and a better fishing administrationin the Baltic Sea area. Risk perception is on the surface practically the same allover but a deeper analysis identifies differences. The four actors all point at different parts ofthe improved fishing-administration as most important. Improved fishing-administration during the 21th century is a fact but not good enough. As long as fishing quotas are not raised considerably during the next few years the Baltic Sea cod should be on the rise and reach biologically safe population. The most important cause for the improved fishing administration is that more actors can take part in the political decisions and that ICES’ biological recommendations are complied with to a larger extent than before. / Uppsatsen behandlar ämnet risk och riskhantering av det svenska torskfisket i Östersjön. Syftet är att redogöra för skillnaderna i riskuppfattning hos aktörer inom fiskenäringen sam tvilka konsekvenser skillnaderna har för de politiska besluten. En litteraturstudie har gjorts föratt ge en kunskapsbakgrund inför intervjuerna med fyra fiskeriaktörer. De utvalda aktörerna är SFR (Svenska Fiskares Riksförbund), Fiskeriverket, WWF och en representant förforskarvärlden. Resultaten i studien visar att orsakerna till torskens förbättrade status är två, en god naturlig förökning samt en bättre förvaltning av fiskeresurserna. Riskuppfattningen skiljer sig inte mycket på ytan mellan aktörerna. En djupare analys identifierar dock skillnadersom inte är lika tydliga vid en första anblick. Aktörerna betonar olika delar av den förbättringsom skett i fiskeförvaltningen, troligtvis beroende på vilken bakgrund de har. Fiskeförvaltningen har blivit bättre under 2000-talet men bestånden är ännu inte betryggande goda. Så länge inga drastiska höjningar av fiskekvoterna sker de närmare åren och beståndenfortsätter öka är risken liten för ännu en kollaps för Östersjötorsken. Den viktigaste orsaken till den förbättrade förvaltningen är att fler aktörer är inblandade i beslutsprocessen och att ICES rekommendationer efterföljs i högre grad i de politiska besluten.

An increasing number of chemicals are being transported by ships along the Swedish coastline. Many of these chemicals may pose a threat to the environment. Accidents and spills are luckily rare, but nonetheless it is important to be prepared for a possible chemical spill. The Swedish Coast Guard is responsible for responding to chemical spills at sea, and has both equipment and trained personnel for the purpose. In order to prepare for a possible accident one also needs to know what is currently being transported at sea. The aim of this project is therefore to survey the chemical transports in Swedish waters. The survey shows that many of the chemicals transported at sea are environmentally harmful and may harm the environment in the event of a spill. The number of accidents that occur is difficult to determine since not all of the smaller ones are reported. It is clear, however, that the main reasons for accidents are groundings and collisions. The collection of information about chemical transports has been difficult because many of the companies and ports are unwilling to give their information. This is part because of concurrence and part due to the fact that it is considered too much work to gather the data. The project also aims to make a risk analysis for chemical transports at sea. Because of the insufficient data the risk analysis has only dealt with qualitative assessments for certain chemicals. These assessments show that chemicals which are less environmentally harmful may still pose a threat because of the safety issues for the personnel may delay or even prevent a response action. International regulations for transports at sea can sometimes be complicated to apply because of the vast number of different chemicals. The classification process takes time because of the extensive research which is needed. Furthermore, many of the chemicals transported are classified in different systems and these do not always correspond. It is therefore difficult to conclude which chemicals that are actually a threat to the environment. / Varje år transporteras allt större mängder kemikalier med fartyg längs Sveriges kust. Många av dessa kan vara farliga för miljön. Olyckor och utsläpp sker lyckligtvis ganska sällan men det krävs ändå en beredskap för att kunna ta hand om ett eventuellt utsläpp. I Sverige har Kustbevakningen ansvaret för miljöräddningstjänst till sjöss och har både utrustning och personal som är speciellt utbildad för att bekämpa just kemikalieutsläpp. För att kunna förbereda sig på en eventuell olycka måste man dock också ha en aktuell bild av vilka kemikalier det är som transporteras till sjöss. Detta projekt har därför syftat till att kartlägga kemikalietransporterna i svenska farvatten. Kartläggningen visar att flera av de kemikalier som transporteras till sjöss är miljöfarliga och kan skada miljön vid ett utsläpp eller en olycka. Hur många olyckor som sker är svårt att veta eftersom många av de mindre olyckorna inte rapporteras. Däremot kan man tydligt se att de vanligaste olycksorsakerna är kollisioner och grundstötningar. Att få tag i uppgifter om hur mycket kemikalier som transporteras har visat sig vara svårt eftersom flera företag och hamnar inte vill tala om hur mycket som transporteras. Det beror dels på konkurrensen mellan kemikalieföretag och dels på att man tycker att det är för jobbigt att behöva sammanställa informationen. Projektet har också syftat till att göra en riskanalys över kemikalietransporterna. På grund av det bristfälliga underlaget har riskanalysen endast behandlat kvalitativa bedömningar av ett antal olika kemikalier. Dessa bedömningar visar att även kemikalier som är mindre miljöfarliga kan utgöra en stor risk eftersom de säkerhetsmässiga riskerna för insatspersonalen kan försena eller till och med förhindra en bekämpningsinsats. De internationella reglerna kring transporter till sjöss kan ibland vara svåra att tillämpa eftersom det finns ett stort antal olika kemikalier. Klassningen av de olika kemikalierna tar också lång tid då det krävs omfattande underlag. Många av kemikalierna som transporteras är dessutom klassade enligt flera olika system och det är inte alltid dessa system överensstämmer. Det kan därför vara svårt att ta reda på vilka kemikalier som egentligen kan anses vara miljöfarliga.

In the year 1783 a fissure eruption from Laki in the southern part of Iceland produced a large amount of volcanic gases during a period of eight months. The volcanic gases and aerosols spread across the northern hem sphere due to ideal weather conditions and had a substantial impact on the environment, human health and also climate effects. This, so called dry fog, caused severe health problems, which led to death casualties, killing animals, crops and other vegetation. The consequence was a widespread famine which was aggravated by a hard and long winter in 1783/84. Analysis shows that the Icelandic volcanoes are the primary risk to produce dry fog that can affect Sweden. The fog will most likely cause severe health effects, such as respiratory and cardiovascular problems. It will also cause damage to the vegetation, especially coniferous trees, and it may affect the water by acid chock. The fog may have great impact on the critical infrastructure in Sweden, depending on magnitude and duration. These types of volcanic hazards are difficult to predict and evaluate due to their sporadic nature and the sparse amount of data that is available. It is therefore important to focus on the consequences and develop the Swedish community preparedness on a general basis to handle this type of event.

System of Rice Intensification (SRI) has been introduced and practiced throughout Thailand. However, the conventional transplanting system is well-accepted among Thai farmers over the country. This paper quantifies and compares costs and benefits of SRI and the conventional system of rice cultivation in Thailand to find the best system for a farmer, the environment and a society. The scope of this paper includes a farmer’s profit, the environmental damages and a society’s net benefits categorized in clay soil and sandy loam conditions. The farmer’s profit consists of a production cost and income. The amount of fertilizer application, level of lethal dose and climate change cost are regarded as environmental damage components. The society has concerned over the farmer’s profit and the environmental cost in a decision. The study uses cost-benefit analysis to investigate mean and variation of profit and cost in monetary term. Monte Carlo simulation is utilized for quantifying risk in each scenario. The study finds that SRI saves the production input and increases yield gain significantly. The most impressive results are a reduction in water consumption and number of seeds. Also, the environmental damage caused by this system is lower due to less amount of chemical fertilizer and pesticide applications as well as a low rate of methane gas emission. Sensitivity analysis shows that SRI has better performance under best and worst case scenarios for both types of soil (clay soil and sandy loam). However, the system contains the highest risk of the farmer’s profit. In conclusion, SRI is more beneficial and efficient than conventional system. Still, risk aspects should be considered in decision making. This study can be employed as a framework for government or any parties, who are interested or have willingness to conduct a field study of SRI and the conventional rice cropping system or for the further study about the integrated system (a combination between SRI and conventional system).

The model building and fire codes in Canada permit prescriptive-based design and performance-based design approaches. Within this regulatory framework, prescriptive-based designs are attributed objective and functional statements to qualify the level of fire protection and life safety required. Performance-based designs, or alternative solutions to prescriptive-based designs, must be demonstrated to achieve at least an equivalent level of performance as the prescriptive requirement based on evaluation of each associated objective and functional statement. Due to the qualitative performance descriptions available, the current system for developing and reviewing alternative solutions is vulnerable to the acceptance of over-designed or under-designed life safety and fire protection measures in buildings. The objective of this thesis is to establish a method to compare the performance of alternative solutions with prescriptive design requirements on a quantitative basis. This thesis generates eight objectives for a fire risk analysis tool to address the challenges identified in the building regulatory industry. Based on review of existing techniques, a new fire risk analysis framework is developed. The Quantitative Design Decision (QDD) method, integrates risk analysis with quantitative decision assessment techniques to facilitate application-specific quantification of performance objectives and to aid evaluation of performance-based designs. The method utilizes an iterative three-stage structure. To demonstrate the application of the QDD method, a case-study simulation has been conducted. The case-study provides an evaluation of alternative designs to the prescriptive requirements for explosion-relief ventilation in rooms housing flammable vapour producing operations. The case study supports the conclusion that QDD achieves the eight objectives set out in this thesis. For validation, the QDD method must be applied to a wider variety of practical design challenges and it is recommended that the results be considered in conjunction with live fire test data to verify key aspects of the performance decisions generated. Future work should include evaluation of Delphi technique application in the Design Decision Stage of the QDD method. It is proposed that the method developed can be extended for use as a general performance-based design tool.

Meander migration is a complex and dynamic process of the lateral movement of a river due to erosion on one bank and deposition on the opposite bank. As a result, the channel migrates in a lateral direction, which might be a major concern for the safety of bridges during their life span of 75 years. Although there are several existing models for predicting meander migration of a river, none of them are based on the physical model tests on a specific type of soil. A total of eight flume tests are conducted to develop a prediction equation of meander migration in clay. The test results of migration rate follow a hyperbolic function, and spatial distribution of the maximum migration distance is fitted with the Pearson IV function. The proposed equations of the initial migration rate and the maximum migration distance, obtained by a multiple regression technique, are validated with the laboratory data. A new methodology for risk analysis is developed to process a number of predicted channel locations based on each future hydrograph generated in such a way that all the hydrographs have the same probability of occurrence. As the output from risk analysis, a CDF map is created for a whole river representing a general trend of migration movement along with the probability associated with new location of the river. In addition, a separate screen is generated with a CDF plot for a given bridge direction so that bridge engineers can read a specific migration distance along the bridge corresponding to the target risk level (e.g. 1 %). The newly developed components through this research are incorporated with the other components in the MEANDER program which is a stand-alone program and the final outcome of the research team. Verification study of the MEANDER program is conducted with full-scale field data at the Brazos River at SH 105, Texas. The prediction results matched quite well with the measured field data. However, a more extensive verification study for other sites is highly recommended.

New maintenance techniques for circuit breakers are studied in this dissertation by proposing a probabilistic maintenance model and a new methodology to assess circuit breaker condition utilizing its control circuit data. A risk-based decision approach is proposed at system level making use of the proposed new methodology, for optimizing the maintenance schedules and allocation of resources. This dissertation is focused on developing optimal maintenance strategies for circuit breakers, both at component and system level. A probabilistic maintenance model is proposed using similar approach recently introduced for power transformers. Probabilistic models give better insight into the interplay among monitoring techniques, failure modes and maintenance techniques of the component. The model is based on the concept of representing the component life time by several deterioration stages. Inspection and maintenance is introduced at each stage and model parameters are defined. A sensitivity analysis is carried to understand the importance of model parameters in obtaining optimal maintenance strategies. The analysis covers the effect of inspection rate calculated for each stage and its impact on failure probability, inspection cost, maintenance cost and failure cost. This maintenance model is best suited for long-term maintenance planning. All simulations are carried in MATLAB and how the analysis results may be used to achieve optimal maintenance schedules is discussed. A new methodology is proposed to convert data from the control circuit of a breaker into condition of the breaker by defining several performance indices for breaker assemblies. Control circuit signal timings are extracted and a probability distribution is fitted to each timing parameter. Performance indices for various assemblies such as, trip coil, close coil, auxiliary contacts etc. are defined based on the probability distributions. These indices are updated using Bayesian approach as the new data arrives. This process can be made practical by approximating the Bayesian approach calculating the indices on-line. The quantification of maintenance is achieved by computing the indices after a maintenance action and comparing with those of previously estimated ones. A risk-based decision approach to maintenance planning is proposed based on the new methodology developed for maintenance quantification. A list of events is identified for the test system under consideration, and event probability, event consequence, and hence the risk associated with each event is computed. Optimal maintenance decisions are taken based on the computed risk levels for each event. Two case studies are presented to evaluate the performance of the proposed new methodology for maintenance quantification. The risk-based decision approach is tested on IEEE Reliability Test System. All simulations are carried in MATLAB and the discussions of results are provided.

A risk review of a fuel cell-based distributed co-generation (FC-Based DCG) system was conducted to identify and quantify the major technological system risks in a worst-case scenario. A risk review entails both a risk assessment and a risk analysis of a designed system, and it is part of risk engineering. Thorough literature reviews and expert interviews were conducted in the field of fuel cells. A thorough literature review of the risk engineering field was also conducted. A procedure for a risk review of the FC-Based DCG System was developed. The representative system design was identified by the current DCG design technology. The risk assessment was carried out, identifying the system components and potential failure modes and consequences. Then, using probabilities of failure for the various system components, the risk associated with a particular system design was determined. A Monte Carlo simulation on the total system reliability was used to evaluate the potential for system failure at a time of 1 hour, 5 hours, 10 hours, 50 hours, 100 hours and 500 hours of continuous operation. The original system was found to be acceptable at the initial times, but after 100 hours was predicted to fail. The components which consistently contribute significantly to the overall system risk are the membrane electrode assembly (MEA) and the nickel-metal foam flow fields. A revised system was analyzed with the reliability of the MEA and the Ni-foam set to 100%. After the revision, the components which contributed significantly to the system risk were the pumps. Simulations were run for several alternative systems to provide feedback on risk management suggestions. The risk engineering process developed with the design approach for this research is applicable to any system and it accommodates the use of many different risk engineering tools.