This thesis investigates the crucial problem of collision avoidance for autonomous vehicles.  An anti-collision system for an unmanned aerial vehicle (UAV) is studied in particular. The purpose of this system is to make sure that the own vehicle avoids collision with other aircraft in mid-air. The sensor used to track any possible threat is for a UAV limited basically to a digital video camera. This sensor can only measure the direction to an intruding vehicle, not the range, and is therefore denoted an angle-only sensor. To estimate the position and velocity of the intruder a tracking system, based on an extended Kalman filter, is used. State estimates supplied by this system are very uncertain due to the difficulties of angle-only tracking. Probabilistic methods are therefore required for risk calculation. The risk assessment module is one of the essential parts of the collision avoidance system and has the purpose of continuously evaluating the risk for collision. To do this in a probabilistic way, it is necessary to assume a probability distribution for the tracking system output. A common approach is to assume normality, more out of habit than on actual grounds. This thesis investigates the normality assumption, and it is found that the tracking output rapidly converge towards a good normal distribution approximation. The thesis furthermore investigates the actual risk assessment module to find out how the collision risk should be determined. The traditional way to do this is to focus on a critical time point (time of closest point of approach, time of maximum collision risk etc.). A recently proposed alternative is to evaluate the risk over a horizon of time. The difference between these two concepts is evaluated. An approximate computational method for integrated risk, suitable for real-time implementations, is also validated. It is shown that the risk seen over a horizon of time is much more robust to estimation accuracy than the risk from a critical time point. The integrated risk also gives a more intuitively correct result, which makes it possible to implement the risk assessment module with a direct connection to specified aviation safety rules.

Risk är en del av all mänsklig aktivitet. Att förutsäga det okända och det som kanske inträffar harvarit ett problem som mänskligheten funderat kring från antiken och framåt. Att finna en förklaringsmodelleller en metod för att med en sannolikhet gränsande till visshet kunna skaffa sig insikti morgondagen har varit och är alltjämt en stor utmaning. Det här arbetet syftar till att skapa klarheti begreppet risk och sätta det i relation till hur Försvarsmakten hanterar bedömningen av riskidag. Uppsatsen täcker den idéhistoriska utvecklingen av begreppet från de klassiska filosofernatill modern tid. För att vidga perspektivet och skapa förståelse för bedömandeprocessen berörs detkognitiva skeendet vid beslutsfattning och några av de fallgropar som är kända. Med denna begreppsförankringsom grund analyseras Försvarsmaktens riskhanteringsmodell i relation till andramotsvarande modeller. Fördelar och nackdelar påvisas. Avslutningsvis finns en rekommendationtill utveckling av modellen för att bättre svara mot de krav på säkerhet som det expeditionära insatsförsvaretkräver. Det är författarens förhoppning att efter läsning av uppsatsen skall läsaren hautvecklat sin personliga uppfattning och sitt medvetande om risk och riskhantering. / Risk is a part of all human activity. To be able to predict the unknown has been a problem of mankind since the ancient Greeks and forward in history. To find a model or method in order to foreseetomorrow with a probability close to certainty has been and is still a big challenge. The purposeof this paper is to clarify the concept of risk and put it in relation to how it is used in theSwedish Armed Forces to day. This essay covers the history of ideas of risk from ancient historyto modern times. To widen the conception and create un understanding of the process of decisionmaking, a part of the paper deals with the cognitive process and some of the common pitfallswithin it. With this foundation in the concept of risk the Swedish Armed Forces model are scrutinizedand compared to other models alike. The pros and cons are described. Finally some suggestionsto develop the model are given in order to make it a valuable tool in support of the new expeditionaryarmed forces. It is the author’s ambition that this essay will contribute to the readerspersonal knowledge about risk and risk management. / Avdelning: ALB - Slutet Mag 3 C-upps. Hylla: Upps. ChP 06-08

Österbyverken is an industrial estate in Östhammars municipality in Uppland, Sweden. Many different activities have taken place on the estate the last 600 years. During the last 15 years both health and environmental studies have been made by different companies. At the most recent study a great increase of metals in Nerån, a river that runs partly through and partly next to the estate, was identified with mass balances. The purpose of this thesis is to accomplish a deepened study about the reasons for the increase of metals in Nerån. The aim is to identify knowledge gaps in the mass balances and try to complete these. From the outcome an environmental risk assessment will be attempted for Nerån and its outlet in the lake Filmsjön. The method went through steps and started with data analyses after which calculations for new mass balances were made. Beginning by acknowledge the increase of metals from the groundwater, both through measured results and through calculated confidence intervals. In addition, among other methods, calculations of theoretical leakage data from Kd-values were made. Surface water concentrations were also compared with levels of metals in sediments to see whether any connection existed between them. Additional mass balances were calculated to take suspended solids in the surface water under consideration. From the results an environmental risk assessment was made using guidelines from Netherland and Canada and the state division from the Swedish Environmental Protection Agency. The results of the study show that the differences of metal content between surface water and groundwater and between surface water and sediments might be smaller than first revealed, but there is still a great increase caused by another, unknown source. The environmental risk assessment shows that there are hazards for both Nerån and Filmsjön because of the leakage of metals from Österbyverken. For the surface water in Nerån it is mainly cobalt, copper and zinc that contributes with risks, for the sediment in Nerån it is mainly barium, cobalt, copper, chromium and nickel and for the sediments in Filmsjön it is mainly lead, cobalt, copper, chromium, nickel and zinc. Reasons for the differences between metal contents and medias might be from surface water outlet from the Österbyverken or because of differences in methods of taking specimens in surface and groundwater. Conclusions that have been drawn of the study is that further studies of the knowledge gaps needs to be done, particularly regarding the metals cobalt, copper, chromium, nickel and zinc. Further, the biodiversity in Nerån and Filmsjön is at risk, partly because several metals in the sediments reaches such high concentrations, partly because high concentrations of several metals in one area may increase risks.

Hazardous Materials (HazMat) are transported throughout Canada in a great number of road shipments. The transportation of HazMat poses special risks for neighboring population and environment. While HazMat accidents are rare events, they could be catastrophic in nature and could result in substantial damage to nearby communities. Effective emergency response plays an important role in the safe transportation of HazMat. Transportation of HazMat involves different parties, including shippers, regulators, and surrounding communities. While the shipping party is responsible for safe delivery of HazMat shipments, it is the responsibility of local emergency service agencies to respond to accidents occurring within their jurisdictions. In this research, the emergency response to HazMat transport accidents is assumed to be delegated exclusively to specially trained and equipped HazMat teams. This research proposes a new comprehensive systematic approach to determine the best location of HazMat teams on regional bases utilizing HazMat transport risk as a location criterion. The proposed model is the first to consider emergency response roles in HazMat transport risk analysis, and was intended as an optimization tool to be used by practitioners for HazMat emergency response planning. Additionally, the proposed model can be used to assess risk implications in regards to current locations of HazMat teams in a region, and to develop effective strategies for locating HazMat teams, such as closing and/or relocating teams in the region. The model investigates how HazMat team locations can be tailored to recognize the risk of transporting HazMat and would provide a more objective set of input alternatives into the multi-criteria decision making process of regionally locating HazMat teams. The proposed model was applied to the region of southwestern Ontario in effort to illustrate its features and capabilities in the HazMat emergency response planning and decision making process. Accordingly, the model provided very useful insights while reviewing several HazMat team location strategies for the southwestern Ontario region and investigating tradeoff among different factors. This research contributes to a better understanding of emergency response roles by reducing HazMat transport risks, and will greatly benefit both researchers and practitioners in the field of HazMat transport and emergency response.

Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.

Njurbiopsi tas för att ställa diagnos och för behandlingskontroll av flera njursjukdomar. En del av sjuksköterskans arbete att förbereda och övervaka patienter. Njurbiopsi är förenat med risken att drabbas av en blödning vilken kan vara livshotande. I Sverige tycks vården vid njurbiopsi skilja sig åt mellan olika sjukhus. Det saknas en systematisk sammanställning av praxis. Syfte: Att beskriva och jämföra aktuellt forskningsläge med svensk praxis samt beskriva sjuksköterskans roll och kompetensbehov vid njurbiopsi. Design och metod: Mixed method approach. Dels en litteraturgenomgång vilken syftade till att identifiera viktiga faktorer vid njurbiopsi dels en inventeringsdel där rutindokument samlades in från svenska njurmedicinska avdelningar. Resultat: Vården kring njurbiopsi har visat sig vara komplex. En mängd värden samlas in före och efter njurbiopsi genom blodprovtagning och andra mätvärden. Det åligger sjuksköterskan att bedöma dessa värden och vid behov konsultera läkare. Det tycks dock råda oklarheter kring vilka åtgärder som har betydelse för komplikationsfrekvensen. Slutsats: Av de insamlade rutindokumenten är det endast ett fåtal som tillhandahåller beskrivningar av hur insamlad information ska tolkas och de utgör således ett svagt handlingsstöd i arbetet för sjuksköterskan som vårdar patienter som genomgår njurbiopsi. / Renal biopsy is performed to diagnose and evaluate treatment in many renal diseases. To prepare and monitor patients is a part of a nurse’s assignments. Renal biopsy is associated with the risk of internal bleeding which may be life-threatening. In Sweden treatment seams to differ between hospitals. There is no systematic compilation of established practice. Aim: To describe and compare current state of the art with swedish practice and also describe the role of the nurse and his or her need of competence in relation to renal biopsy. Design and method: Mixed method approach. Partly a literature review which aimed to identify important factors in relation to renal biopsy. Partly an inventory where directions of the procedure was collected from swedish nephrology wards. Result: Treatment and care in relation to renal biopsy has shown to be complex. A quantity of values were collected prior to and after renal biopsy by blood testing and and other measurements. It is the nurse’s assignment to assess these values and when necessary consult medical personnel. Yet there seems to be some uncertainty as regarding which measurements and actions that influence the outcome. Conclusion: Out of the collected directions of procedure there is only a few that offer descriptions of how observed data should be assessed and accordingly they constitute a weak support for nurses in their line of work when caring for patients that undergo renal biopsy.

Chemicals and additives in products being produced and marketed globally, this makes an international harmonised assessment and management essential. Chemical testing, research on risks, impacts and management options are carried out throughout the globe but quite fractionated to certain areas and sectors and much too often with little linkages between the different scientific communities. The coordination action (CA) \"RISKCYCLE\" is aimed to establish and o-ordinate a global network of European and international experts and stakeholders to define together future needs of R+D contributions for innovations in the risk-based management of chemicals and products in a circular economy of global scale leading to alternative strategies to animal tests and reduced health hazards. The partners joining this action seek to explore the synergies of the research carried out within different programmes and countries of the EU, in Asia and overseas to facilitate the intensified communication with researchers, institutions and industries about the risks of hazardous chemicals and additives in products and risk reduction measures and to improve the dispersion of available information. The RISKCYCLE network will closely collaborate with related projects, EU and international bodies and authorities such as for example the Organisation for Economic Co-operation and Development (OECD), the European Chemical Industry Council (CEFIC) and the Scientific Committee on Health and Environmental Risks in Europe. / Mục đích chính của RISKCYCLE là xác đinh các nghiện cứu và sự phát triển trong tương lai cấn thiết để thành lập một phương pháp đánh giá dựa trện rủi ro cho các hoá chất và các sản phấm. Phương pháp này sẽ giúp giảm bớt các thủ nghiệm trện động vật, đổng thời đảm bảo sự phát triển các hóa chất mới và một mô hình quản lý sản phấm để giảm thiểu rủi ro đối với sức khởe và môi trường. để đạt được mục tiệu này, trước hết cấn thu thập và đánh giá thông tin hiện có về các hoá chất và đặc biệt là các chất phụ gia được sủ dụng trong sản phấm công nghiệp và tiệu dùng. Nhiều hợp chất độc hại tiềm tàng được giao dich mua bán trện toàn thế giới như là chất phụ gia trong các sản phấm khác nhau. RISKCYCLE sẽ tập trung vào tác động và hậu quả của các chất phụ gia trong sáu lĩnh vực: dệt may, điện tủ, nhựa, da, giấy và dấu mớ bôi trơn. Trong ngành công nghiệp dệt may việc sủ dụng các chất phụ gia sẽ được nghiện cứu, trong khi ở ngành điện tủ và công nghiệp dệt may, việc sủ dụng các chất chống cháy, đặc biệt là chất chống cháy chứa brôm như PBDEs và HBCD, sẽ được phân tích. Trong công nghiệp da, kim loại nặng như crom sẽ được quan tâm. Việc sủ dụng chất diệt côn trùng trong ngành công nghiệp giấy cũng sẽ là một mối quan tâm chính của các hoạt động phối hợp.

Real-world problems especially the ones that involve natural systems are complex and they are composed of many non-deterministic components. Uncertainties associated with these non-deterministic components may originate from randomness or from imprecision due to lack of information. Until recently, uncertainty, regardless of its nature or source has been treated by probability concepts. However, uncertainties associated with real-world systems are not limited to randomness. Imprecise, vague or incomplete information may better be represented by other mathematical tools, such as fuzzy set theory, possibility theory, belief functions, etc. New approaches which allow utilization of probability theory in combination with these new mathematical tools found applications in various engineering fields. Uncertainty modeling in human health risk assessment and groundwater resources management areas are investigated in this thesis. In the first part of this thesis two new approaches which utilize both probability theory and fuzzy set theory concepts to treat parameter uncertainties in carcinogenic risk assessment are proposed. As a result of these approaches fuzzy health risks are generated. For the fuzzy risk to be useful for practical purposes its acceptability with respect to compliance guideline has to be evaluated. A new fuzzy measure, the risk tolerance measure, is proposed for this purpose. The risk tolerance measure is a weighed average of the possibility and the necessity measures which are currently used for decision making purposes. In the second part of this thesis two decision making frameworks are proposed to determine the best groundwater resources management strategy in the Savannah region, Georgia. Groundwater resources management problems, especially ones in the coastal areas are complex and require treatment of various uncertain inputs. The first decision making framework proposed in this study is composed of a coupled simulation-optimization model followed by a fuzzy multi-objective decision making approach while the second framework includes a groundwater flow model in which the parameters of the flow equation are characterized by fuzzy numbers and a decision making approach which utilizes the risk tolerance measure proposed in the first part of this thesis.

This work is study 71 kinds of volatile organic compounds (VOCs) in the sewer system of a metropolitan city during dry/wet weather. The VOCs contains alkanes, alkenes and alkynes, aromatics, chlorinated organics, sulfides, ketones and ethers. The purpose of this work estimated the emission rates of VOCs and cancer risk within 12 kinds of hazardous air pollutants (HAPs) will be part of the investigation 26 HAPs by using risk assessment. TVOCs (concentrations of total VOCs) in dry weather was higher than that in wet weather for both sewer systems. The concentration distributions of dominant were KB7 (C3) in the A (B) sewer system. This system collected sewage from harbor and industrial park. During dry and wet weather, the most common VOCs were chlorinated organics and alkanes in the A sewer system, respectively. The main contribution were chloroethene and isopentane; the most common VOCs were aromatics in the B sewer system. The main contribution was m / p-Xylene. This results show that the most emission rates of TVOCs is C3 (13,834.79 mg/hr) during dry weather and KB2 (1875.25 mg/hr) during wet weather. The emission rates of K1

Alkylphenol polyethoxylates (APEOs), a class of nonionic surfactants, have been widely used for industrial, agricultural and household applications. The biodegradation metabolites of APEOs, such as nonylphenol and octylphenol, are more persistent and known to disrupt endocrine function in wildlife and human. These compounds are also recognized as endocrine disrupting chemicals (EDCs). The objectives of this study were to investigate the distribution and removal efficiencies of EDCs, including nonylphenol diethoxylates (NP2EO), nonylphenol monoethoxylates (NP1EO), nonylphenol (NP) and octylphenol (OP), of wastewater treated by the constructed wetland systems along the Dahan River and around the Dapeng Bay, respectively. In addition, the method of risk quotient was used to evaluate the potential ecological risk of APEOs to aquatic organisms in current study. The water samples collected from 32 sampling sites in the Dapeng Bay National Scenic Area including Datan, Pengcun and Linbain right bank constructed wetlands. The samples were then concentrated by solid phase extraction, and analyzed for target compounds by HPLC/fluorescence. According to the results, nonylphenol diethoxylates, nonylphenol monoethoxylates, nonylphenol and octylphenol were found approximately equal to 29.9, 47.3, 20.5 and 57.7 %, respectively of the samples from three constructed wetlands with concentrations ranged from <3.3 to 968.7, <3.3 to 226.5, <1.3 to 238.4 and <1.0 to 1458.7 ng/L, respectively. Temporal variation of APEOs showed a decreasing in the order of summer¡Öspring¡Öwinter¡Öautumn. The removal efficiencies of APEOs in these constructed wetlands showed a decreasing order of Datan wetland¡ÖPengcun wetland¡ÖLinbain right bank wetland. In addition, the samples collected from 18 sampling sites from the constructed wetlands along the riparian of Dahan River including Daniaopi, Hsin-Hai Bridge Phases I and II constructed wetlands. According to the results, nonylphenol diethoxylates, nonylphenol monoethoxylates, nonylphenol and octylphenol were found approximately equal to 91.9¡B84.8¡B17.1 and 73.7 %, respectively of samples collected from three constructed wetlands with concentrations ranged from <3.3 to 11191.5, <3.3 to 6069.0, <1.3 to 671.0 and <1.0 to 5581.9 ng/L, respectively. The removal potential of APEOs in these constructed wetlands showed a decreasing order of Hsin-Hai Bridge Phases II¡ÖDaniaopi¡ÖHsin-Hai Bridge Phases I constructed wetland. Regarding the ecological assessment in this research, the calculated risk quotients were up to 30 times higher in the constructed wetland systems of Dahan River than those in the Dapeng Bay National Scenic Area, indicating that the existing concentrations of these EDCs in wetland systems might cause potential ecological risks to aquatic organisms. Furthermore, the decreasing risk quotient from influent to effluent indicating the capabilities of treating alkylphenolic compounds in these constructed wetlands.