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Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 223 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 217-223).

OHSAS 18000 Occupational Health and Safety Assessment System Series have a special importance to mining. OHSAS standardization aims to provide secure, more tranquil and healthier working space to the employees by means of establishing an assessment system. As mining activities are generally carried out in high risk environments, OHSAS has been improved and has increased its importance for mining in the world. In this study, Bigadi&ccedil / Boron Work is taken as a case for the application of OHSAS 18001. Theoretical information about OHSAS and risk assessment is provided, and some exemplifying mines that implemented this standard are given to illustrate their benefits. All possible hazard sources are identified and a &ldquo / Hazard Source Inventory&rdquo / is proposed. Together with this hazard source inventory, a risk assessment method is developed for Bigadi&ccedil / Boron Work. Several tasks are evaluated according to this proposed form. In order to define policy, principles and structure of Occupational Health and Safety Assessment System, an &ldquo / OHSA Manual&rdquo / is prepared. Several sets of standard forms were prepared and recommended for Bigadi&ccedil / Boron Work. Consistency throughout the organization was established by means of these created standard documents, procedures and forms. Proposed Job Safety Analysis form can be used to identify, analyze and record the steps involved in performing a specific task, and the existing or potential safety and health hazards associated with each step. Several safe job procedures were also prepared with the help of the risk assessment process. In addition to this, an &ldquo / Emergency Plan&rdquo / is proposed for enterprise to prevent loss of life, property and information, and provide safety in case of any emergency or natural disaster. An &ldquo / OHS Audit Instrument&rdquo / is suggested for the Bigadi&ccedil / Boron Work that will play a key role for continuous improvement of the system. Audits are integral part of OHSAS in order to identify hazards, improve health and safety conditions, and check compliance with regulations. These studies also show that there are some problems in the implementation of the system. The main problem is ineffective data recording and keeping. Lack of consciousness of employees and low commitment of top management constitute another important difficulty. Although these problems are commonly encountered in practice, applying OHSAS 18000 standard is still worthwhile method of improving work environment.

Safety risk assessment forms an integral part of the design and development of Safety Critical Systems. Conventionally in these systems, standards and policies have been developed to prescribe processes for safety risk assessment. These standards provide guidelines, references and structure to personnel involved in the risk assessment process. However, in some of these standards, the prescribed methods for safety decision making were found to be deficient in some respects. Two such deficiencies have been addressed in this thesis. First, when different safety metrics are required to be combined for a safety related decision, the current practices of using safety risk matrices were found to be inconsistent with the axioms of decision theory. Second, in the safety risk assessment process, when multiple experts are consulted to provide their judgment on the severity and/or likelihood of hazards, the standards were lacking detailed guidelines for aggregating experts' judgements. Such deficiencies could lead to misconceptions pertaining to the safety risk level of critical hazards. These misconceptions potentially give rise to inconsistent safety decisions that might ultimately result in catastrophic outcomes. This thesis addresses both these concerns present in SRM processes. For the problem of combining safety metrics, three potential approaches have been proposed. Normative Decision Analysis tools such as Utility Theory and Multi-attribute Utility Theory were proposed in the first and second approaches. The third approach proposes the use of a Multi-Objective Optimization technique - Pareto Analysis. For problems in Expert Aggregation, behavioral and mathematical solutions have been explored and the implications of using these methods for Safety Risk Assessment have been discussed. Two standard documents that contain the Safety Risk Management Processes of the Federal Aviation Agency (FAA) and the U.S. Navy were used to structure the case studies. This thesis has two main contributions. First, it evaluates the use of decision analysis in safety decision process of Safety Critical Systems. It provides guidelines to decision makers on how to meaningfully use and/or combine different safety metrics in the decision process. Second, it identifies the best practices and methods of aggregating expert assessments pertaining to safety decision making. / Master of Science / Safety risk assessment forms an important part of the design and development of Safety Critical Systems. Safety Critical Systems are those systems whose failure could potentially result in the loss of human life. Commonly in these systems, standards and policies have been developed to prescribe processes for safety risk assessment. These standards provide guidelines, references and structure to personnel involved in the risk assessment process. However, in some of these standards, the prescribed methods for safety decision making were found to be deficient in some respects. Two such deficiencies have been addressed in this thesis. First, when different safety metrics are required to be combined to provide information for a safety related decision, the current practices of the safety risk assessment do not yield consistent recommendations. Second, in the safety risk assessment process, often multiple experts are consulted to provide their judgment on the criticality of a potential safety risk of the system. The standards and policies that are currently being used, do not provide clear instructions on how to synthesize the judgements of multiple experts. This lack of clear guidelines could potentially lead to an incorrect final judgement on the criticality of the risk and ultimately result in choosing an improper method to reduce the safety risk. This thesis addresses both these concerns present in safety risk assessment process of Safety Critical Systems. For the problem of combining safety metrics, three approaches have been proposed. Two of the proposed approaches make use of normative decision analysis practices and therefore the recommendations reached using these methods will be consistent with the safety objective of the decision maker. The third approach makes use of a traditional concept called -Pareto Analysis which provides a visual method to analyze the advantages and drawbacks of a given safety concern for a system. For problems in combining the judgements of multiple experts a variety of methods was studied. The methods include group consensus and mathematical techniques and the implications of using these methods in safety risk assessment was discussed. The FAA and the U.S. Navy's standard documents and policies were used to frame the discussions. This thesis has two main contributions. First, it evaluates the use of Normative Decision Analysis methods in safety decision process of Safety Critical Systems. It provides guidelines to decision makers on how to meaningfully use and/or combine different safety metrics in the decision process. Second, it identifies the best practices and methods of aggregating expert assessments pertaining to safety decision making.

The work presented in this thesis was undertaken as part of the safety work package of the NATURALHY project which was an integrated project funded by the European Commission (EC) within the sixth framework programme. The purpose of the NATURALHY project was to investigate the feasibility of using existing natural gas infrastructure to assist a transition to a hydrogen based economy by transporting hydrogen from its place of production to its place of use as a mixture of natural gas and hydrogen. The hydrogen can then be extracted from the mixture for use in fuel cells or the mixture used directly in conventional combustion devices. The research presented in this thesis focused on predicting the consequences of explosions and fires involving natural gas and hydrogen mixtures, using engineering type mathematical models typical of those used by the gas industry for risk assessment purposes. The first part of the thesis concentrated on modifying existing models that had been developed to predict confined vented and unconfined vapour cloud explosions involving natural gas. Three geometries were studied: a confined vented enclosure, an unconfined cubical region of congestion and an unconfined high aspect ratio region of congestion. The modifications made to the models were aimed at accounting for the different characteristics of a natural gas/hydrogen mixture compared to natural gas. Experimental data for the laminar burning velocity of methane/hydrogen mixtures was obtained within the safety work package. For practical reasons, this experimental work was carried at an elevated temperature. Predictions from kinetic modelling were employed to convert this information for use in models predicting explosions at ambient temperature. For confined vented explosions a model developed by Shell (SCOPE) was used and modified by adding new laminar burning velocity and Markstein number data relevant to the gas compositions studied. For vapour cloud explosions in a cubical region of congestion, two models were used. The first model was developed by Shell (CAM2), and was applied using the new laminar burning velocity and other composition specific properties. The second model was based on a model provided by GL Services and was modified by generalising the flame speed model so that any natural gas/hydrogen mixture could be simulated. For vapour cloud explosions in an unconfined high aspect ratio region of congestion, a model from GL Services was used. Modifications were made to the modelling of flame speed so that it could be applied to different fuel compositions, equivalence ratios and the initial flame speed entering the congested region. Predictions from the modified explosion models were compared with large scale experimental data obtained within the safety work package. Generally, (apart from where continuously accelerating flames were produced), satisfactory agreement was achieved. This demonstrated that the modified models could be used, in many cases, for risk assessment purposes for explosions involving natural gas/hydrogen mixtures. The second part of thesis concentrated on predicting the incident thermal radiation from high pressure jet fires and pipelines fires involving natural gas/hydrogen mixtures. The approach taken was to modify existing models, developed for natural gas. For jet fires three models were used. Fuel specific input parameters were derived and the predictions of flame length and incident radiation compared with large scale experimental data. For pipeline fires a model was developed using a multi-point source approach for the radiation emitted by the fire and a correlation for flame length. Again predictions were compared with large scale experimental data. For both types of fire, satisfactory predictions of the flame length and incident radiation were obtained for natural gas and mixtures of natural gas and hydrogen containing approximately 25% hydrogen.

The management of health and safety risks in the oil refinery tends to be centred on the collection and simulation of technical data which can then be used to make decisions on the wellbeing of the workforce as well as the refinery installations. While the number crunching in the process is immensely vital, there tends to be a problem of ignoring or, at the very least, side-lining the social-cultural values of the people dealing with health and safety risk assessment processes. The economic driver for the operation of the oil refinery tends to be more important because of the generally huge initial financial outlay, and the eventual high costs of maintenance; hence health and safety risk management should have evidence of ensuring that the installations, as well as the people that work in them, are well catered for. In the Kuwait Gulf Oil Company this problem is more evident in newer installations where lean management processes have been instituted by oil firms so that they can reduce waste in the oil refining process without compromising the occupational health and safety needs of the refinery. Therein lies the initial problem of integrating health and safety risk assessment processes because most approaches concentrate on the technical elements of waste elimination while ignoring the social-cultural factors that impact on the health and safety of the workforce. This is an exploratory piece of research that examines the impact of rational and cognitive decision theories – herein called the psychology of risk – and how they impact on the occupational health and safety systems in the oil and gas refining sector of Kuwait. The research concludes that the application of lean concepts in the oil refining process is noble in itself but it needs to be integrated with the rational and cognitive detection factors that are necessary to incorporate and support the social-cultural tendencies of the workforce. The research recommends a framework for incorporating social-cultural values in the decision making process pertaining to health and safety risk assessment in oil refining process plants. Key Words: occupational health and safety risk assessment; lean management; social-cultural values; rational and cognitive decision making; oil and gas process plants.

Autonomous driving is increasingly popular among people and automotive industries in realizing their presence both in passenger and goods transportation. Safer autonomous navigation might be very challenging if there is a failure in sensing system. Among several sensing systems, image classification plays a major role in understanding the road signs and to regulate the vehicle control based on urban road rules. Hence, a robust classifier algorithm irrespective of camera position, view angles, environmental condition, different vehicle size & type (Car, Bus, Truck, etc.,) of an autonomous platform is of prime importance. In this study, Convolutional Neural Network (CNN) based classifier algorithm has been implemented to ensure improved robustness for recognizing traffic signs. As training data play a crucial role in supervised learning algorithms, there come an effective dataset requirement which can handle dynamic environmental conditions and other variations caused due to the vehicle motion (will be referred as challenges). Since the collected training data might not contain all the dynamic variations, the model weakness can be identified by exposing it to variations (Blur, Darkness, Shadow, etc.,) faced by the vehicles in real-time as a initial testing sequence. To overcome the weakness caused due to the training data itself, an effective augmentation technique enriching the training data in order to increase the model capacity for withstanding the variations prevalent in urban environment has been proposed. As a major contribution, a framework has been developed to identify model weakness and successively introduce a targeted augmentation methodology for classification improvement. Targeted augmentation is based on estimated weakness caused due to the challenges with difficulty levels, only those necessary for better classification were then augmented further. Predictive Augmentation (PA) and Predictive Multiple Augmentation (PMA) are the two proposed methods to adapt the model based on targeted challenges by delivering with high numerical value of confidence. We validated our framework on two different training datasets (German Traffic Sign Recognition Benchmark (GTSRB) and Heavy Vehicle data collected from bus) and with 5 generated test groups containing varying levels of challenge (simple to extreme). The results show impressive improvement by ≈ 5-20% in overall classification accuracy thereby keeping their high confidence.

Nowadays, rail transport has become one of the most widely utilised forms of transport thanks to its high safety level, large capacity, and cost-effectiveness. With the railway network's continuous development, including urban rail transit, one of the major areas of increasing attention and demand is ensuring safety or risk management in operation long-term remains for the whole life cycle by scientific tools, management of railway operation (Martani 2017), specifically in developed and developing countries like Vietnam. The situation in Vietnam demonstrates that the national mainline railway network has been built and operated entirely in a single narrow gauge (1000mm) since the previous century, with very few updates of manual operating technology. This significantly highlights that up to now, the conventional technique for managing the safety operation in general, and collision in particular, of the current Vietnamese railway system, including its subsystems, is only accident statistics which is not a scientific-based tool as the others like risk identify and analyse methods, risk mitigation…, that are already available in many countries. Accident management of Vietnam Railways is limited and responsible for accident statistics analysis to avoid and minimise the harm caused by phenomena that occur only after an accident. Statistical analysis of train accident case studies in Vietnam railway demonstrates that, because hazards and failures that could result in serious system occurrences (accidents and incidents) have not been identified, recorded, and evaluated to conduct safety-driven risk analysis using a well-suited assessment methodology, risk prevention and control cannot be achieved. Not only is it hard to forecast and avoid events, but it may also raise the chance and amount of danger, as well as the severity of the later effects. As a result, Vietnam's railway system has a high number of accidents and failure rates. For example, Vietnam Rail-ways' mainline network accounted for approximately 200 railway accidents in 2018, a 3% increase over the previous year, including 163 collisions between trains and road vehicles/persons, resulting in more than 100 fatalities and more than 150 casualties; 16 accidents, including almost derailments, the signal passed at danger… without fatality or casual-ty, but significant damage to rolling stock and track infrastructure (VR 2021). Focusing and developing a new standardised framework for safety management and availability of railway operation in Vietnam is required in view of the rapid development of rail urban transport in the country in recent years (VmoT 2016; VmoT 2018). UMRT Line HN2A in southwest Hanoi is the country's first elevated light rail transit line, which was completed and officially put into revenue service in November 2021. This greatly highlights that up to the current date, the UMRT Line HN2A is the first and only railway line in Vietnam with operational safety assessment launched for the first time and long-term remains for the whole life cycle. The fact that the UMRT Hanoi has a large capacity, more complicated rolling stock and infrastructure equipment, as well as a modern communica-tion-based train control (CBTC) signalling system and automatic train driving without the need for operator intervention (Lindqvist 2006), are all advantages. Developing a compatible and integrated safety management system (SMS) for adaption to the safety operating requirements of this UMRT is an important major point of concern, and this should be proven. In actuality, the system acceptance and safety certification phase for Metro Line HN2A prolonged up to 2.5 years owing to the identification of difficulties with noncompliance to safety requirements resulting from inadequate SMS documents and risk assessment. These faults and hazards have developed during the manufacturing and execution of the project; it is impossible to go back in time to correct them, and it is also impossible to ignore the project without assuming responsibility for its management. At the time of completion, the HN2A metro line will have required an expenditure of up to $868 million, thus it is vital to create measures to prevent system failure and assure passenger safety. This dissertation has reviewed the methods to solve the aforementioned challenges and presented a solution blueprint to attain the European standard level of system safety in three-phase as in the following: • Phase 1: applicable for lines that are currently in operation, such as Metro Line HN2A. Focused on operational and maintenance procedures, as well as a training plan for railway personnel, in order to enhance human performance. Complete and update the risk assessment framework for Metro Line HN2A. The dissertation's findings are described in these applications. • Phase 2: applicable for lines that are currently in construction and manufacturing, such as Metro Line HN3, Line HN2, HCMC Line 1 and Line 2. Continue refining and enhancing engineering management methods introduced during Phase 1. On the basis of the risk assessment by manufacturers (Line HN3, HCMC Line 2 with European manufacturers) and the risk assessment framework described in Chapter 4, a risk management plan for each line will be developed. Building Accident database for risk assessment research and development. • Phase 3: applicable for lines that are currently in planning. Enhance safety requirements and life-cycle management. Building a proactive Safety Culture step by step for the railway industry. This material is implemented gradually throughout all three phases, beginning with the creation of the concept and concluding with an improvement in the attitude of railway personnel on the HN2A line. In addition to this overview, Chapters 4 through Chapter 9 of the dissertation include particular solutions for Risk assessment, Vehicle and Infrastructure Maintenance methods, Inci-dent Management procedures, and Safety Culture installation. This document focuses on constructing a system safety concept for railway personnel, providing stringent and scientific management practises to assure proper engineering conditions, to manage effectively the metro line system, and ensuring passenger safety in Hanoi's metro operation

<p>Sprovedena studija po prvi put izve&scaron;tava o prisustvu patulina, sekundarnog metabolita određenih vrsta plesni, u proizvodima od jabuka, kao i proceni rizika usled unosa patulina od strane odojčadi, dece, adolescenata i odrasle populacije u Republici Srbiji. Ukupno 356 uzoraka sokova i ka&scaron;ica za odojčad i malu decu (48 i 66, redom), sokova za decu (mala pakovanja sa cevčicom, 100) i sokova u porodičnom pakovanju (142), sakupljeno je sa trži&scaron;ta tokom tri godine i analizirano primenom tečne hromatografije sa ultraljubičastom detekcijom, metodom koja je predhodno validirana. Prisustvo patulina je detektovano u 44% i 17% uzoraka sokova i ka&scaron;ica za odojčad i malu decu, redom, u količinama nižim od zakonskog ograničenja od 10 &mu;g/kg (maksimalno 8,3 i 7,7 &mu;g/kg, redom). Udeo kontaminiranih uzoraka među sokovima za decu iznosio je 43%, sa najvi&scaron;om koncentracijom patulina od 30,2 &mu;g/kg ispod maksimalno dozvoljenog nivoa od 50 &mu;g/kg. Patulin je detektovan u 51% sokova u porodičnom pakovanju, sa 0,7% uzoraka iznad zakonske granice od 50 &mu;g/kg (prosečna koncentracija 4,3 &mu;g/kg). Sokovi od jabuka su pokazali značajno vi&scaron;i udeo kontaminiranih uzoraka (74% u odnosu na 28%), kao i vi&scaron;i prosečni sadržaj patulina (6,4 u odnosu na 2,1 &mu;g/kg) u poređenju sa sokovima od me&scaron;anog voća. Procena rizika usled unosa patulina od strane odojčadi, dece, adolescenata i odrasle populacije u Republici Srbiji, sprovedena primenom determinističkog i probabilističkog pristupa, uključujući rezultate biodostupnosti patulina, pokazala je da je odnos između procenjenog dnevnog unosa i toksikolo&scaron;ke referentne doze za patulin od 0,4 &mu;g/kg telesne mase, koji se označava kao &ldquo;hazard quotient&rdquo;, znatno ispod 1, &scaron;to ukazuje na tolerantan nivo izloženosti i nepostojanje razloga za zabrinutost za zdravlje populacije. Dodatno, analiza ostataka pesticida i toksičnih metala potvrdila je bezbednost proizvoda od jabuka na trži&scaron;tu. Međutim, identifikacija vi&scaron;estrukih ostataka pesticida je razlog za aktivan pristup i pažljivo planiranje i sprovođenje monitoringa bezbednosti hrane, posebno hrane za odojčad i malu decu, kao najosetljivije populacione grupe.</p> / <p>This study reports for the first time the occurrence of patulin, a secondary metabolite of certain fungi, in apple-based food, as well as risk assessment related to patulin intake by infants, children, adolescents and adults in Serbia. In total, 356 samples of infant fruit juices (48), infant pur&eacute;e (66), juices for children (small package with straw, 100), and juices in family package (142) were collected from the market over three years (2013&ndash;15) and analysed using validated method based on liquid chromatography with ultraviolet detection. Patulin was found in 44% of infant juices and 17% of infant pur&eacute;e, with all values below the legal limit of 10 &mu;g/kg (maximum 8.3 and 7.7 &mu;g/kg, respectively). The proportion of contaminated samples among fruit juices for children was 43%, with the highest patulin concentration at 30.2 &mu;g/kg, not exceeding the maximum allowed level of 50 &mu;g/kg. Patulin was found in 51% of juices in family package, with 0.7% of the samples in excess of the legal limit of 50 &mu;g/kg (mean 4.3 &mu;g/kg). Apple juices showed significantly higher percentage of contaminated samples (74% versus 28%), as well as higher mean patulin content (6.4 versus 2.1 &mu;g/kg) when compared with the multifruit ones. Risk assessment of patulin intake by Serbian infants, children, adolescents and adults, conducted by deterministic and probabilistic approaches and including the bioaccessibility results, revealed a ratio between exposure and toxicological reference dose for patulin of 0,4 &mu;g/kg body weigth, called hazard quotients, well below 1, indicating a tolerable exposure level and no health concern. Furthermore, analysis of pesticide residues and toxic metals confirmed safety of apple products on the market. However, identification of multiple pesticide residues is a reason for an active attitude and carefully planned and conducted monitoring of food safety, expecialy in the case of food for infants and young children, as they are the most susceptible population group.</p>

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