The utilization of renewable energy resources such as wind and solar energy for electric power supply has received considerable attention in recent years due to adverse environmental impacts and fuel cost escalation associated with conventional generation. At the present time, wind and/or solar energy sources are utilized to generate electric power in many applications. Wind and solar energy will become important sources for power generation in the future because of their environmental, social and economic benefits, together with public support and government incentives. <p>The wind and sunlight are, however, unstable and variable energy sources, and behave far differently than conventional sources. Energy storage systems are, therefore, often required to smooth the fluctuating nature of the energy conversion system especially in small isolated applications. The research work presented in this thesis is focused on the development and application of reliability and economic benefits assessment associated with incorporating wind energy, solar energy and energy storage in power generating systems. A probabilistic approach using sequential Monte Carlo simulation was employed in this research and a number of analyses were conducted with regards to the adequacy and economic assessment of generation systems containing wind energy, solar energy and energy storage. The evaluation models and techniques incorporate risk index distributions and different operating strategies associated with diesel generation in small isolated systems. Deterministic and probabilistic techniques are combined in this thesis using a system well-being approach to provide useful adequacy indices for small isolated systems that include renewable energy and energy storage. The concepts presented and examples illustrated in this thesis will help power system planners and utility managers to assess the reliability and economic benefits of utilizing wind energy conversion systems, solar energy conversion systems and energy storage in electric power systems and provide useful input to the managerial decision process.

This study presents the results of probabilistic modeling of plane and wedge types of slope failures, based on the &rdquo / Advance First Order Second Moment (AFOSM)&rdquo / reliability method. In both of those failure types, two different failure criteria namely, Coulomb linear and Barton Bandis non-linear failure criteria are utilized in the development of the probabilistic models. Due to the iterative nature of the AFOSM method, analyzing spreadsheets have been developed in order to carry out the computations. The developed spreadsheets are called &ldquo / Plane Slope Analyzer (PSA)&rdquo / and &ldquo / Wedge Slope Analyzer (WSA)&rdquo / . The developed probabilistic models and their spreadsheets are verified by investigating the affect of rock and slope parameters such as, ground water level, slope height, cohesion, friction angle, and joint wall compressive strength (JCS) and their distribution types on the reliability index (&amp / #946 / ), and probability of slope failure (PF). In this study, different probability distributions are used and the inverse transformation formulas of their non-normal variates to their equivalent normal ones are developed as well. In addition, the wedge failure case is also modeled by using system reliability approach and then the results of conventional probability of failure and the system reliability approach are compared.

The main aim of the present study is to evaluate the safety level of Turkish type precast prestressed concrete bridge girders designed according to American Association of State Highway and Transportation Officials Load and Resistance Factor Design (AASHTO LRFD) based on reliability theory. Span lengths varying from 25 m to 40 m are considered. Two types of design truck loading models are taken into account: H30S24-current design live load of Turkey and HL93-design live load model of AASHTO LRFD. The statistical parameters of both load and resistance components are estimated from local data and published data in the literature. The bias factors and coefficient of variation of live load are estimated by extrapolation of cumulative distribution functions of maximum span moments of truck survey data (Axle Weight Studies) that is gathered from the Division of Transportation and Cost Studies of the General Directorate of Highways of Turkey. The uncertainties associated with C40 class concrete and prestressing strands are evaluated by the test data of local manufacturers. The girders are designed according to the requirements of both Service III and Strength I limit states. The required number of strands is calculated and compared. Increasing research in the field of bridge evaluation based on structural reliability justifies the consideration of reliability index as the primary measure of safety of bridges. The reliability indexes are calculated by different methods for both Strength I and Service III limit states. The reliability level of typical girders of Turkey is compared with those of others countries. Different load and resistance factors are intended to achieve the selected target reliability levels. For the studied cases, a set of load factors corresponding to different levels of reliability index is suggested for the two models of truck design loads. Analysis with Turkish type truck models results in higher reliability index compared to the USA type truck model for the investigated span lengths

Rock slope stability is considered as one of the most important fields in rock engineering. Developments of computation facilities and increase in application of sophisticated mathematical concepts in engineering problems have also affected the methods of slope stability analysis. In recent years, the numerical modeling methods have extensively applied instead of limit equilibrium methods. Also, the probabilistic methods are considered in rock slope designs to quantify the uncertainties of input effecting variables. In this research, a probabilistic-numerical approach was developed by integration of three dimensional Distinct Element Method (DEM) and probabilistic approach to analyze the stability of discontinuous rock slopes. Barton models have been used to model the behavior of rock discontinuities and the shear strain was considered as failure indicator of discontinuities. The proposed methodology was applied to a rock slope in Amasya, Turkey where the Joint Roughness Coefficient (JRC) was considered as the main random variable. The effect of basic friction angle and cohesion of joints infilling material and its strength reduction due to weathering were included in the analysis. In the slope the shearing behavior of fourteen discontinuities and the failure probability of each block were investigated, and the corresponding Reliability Index (&beta / ) was derived for each of the discontinuities.

The dissertation presents GALAS models for the estimation of the acute toxicity towards two rodent species following different administration routes as well as for the prediction of CYP3A4 and CYP2D6 regioselectivity in the main metabolic reactions mediated by these enzymes (13 individual models in total). All these models feature the ability of the quantitative model Applicability Domain (AD) evaluation via the estimated prediction Reliability Indices (RI). I.e., the obtained models conform to one of the main requirements for the QSAR model acceptance as an alternative research method by the EU regulatory institutions. Evident correlation between prediction reliability and its accuracy allowed classifying each model result into one of several qualitative classes according to RI values. One possible way of utilizing such information, discussed in this study, is compound prioritization before experimental testing potentially resulting in reduction of the number of necessary measurements. As demonstrated the AD of the obtained GALAS models can be easily expanded to cover specific compound classes of researcher interest using ‘in-house’ databases of experimental data. This feature significantly improves the possibilities for the practical application of these models, based on public data, in industry. Especially given the fact that the described improvements in predictions following the addition of similar compounds was instant and required no rebuilding of the baseline models. / Disertacijoje pristatomi GALAS metodika paremti ūmaus toksiškumo dviems graužikų rūšims bei visai eilei skirtingų medžiagos patekimo į organizmą būdų ir CYP3A4 bei CYP2D6 fermentų regioselektyvumo pagrindinėse jų katalizuojamose metabolizmo reakcijose prognozavimo modeliai (iš viso 13 individualių modelių). Visi minimi modeliai kokybiškai išsiskiria iš anksčiau publikuotų savo analogų dėl kiekybinio jų pritaikomumo srities įvertinimo galimybės, kurią suteikia apskaičiuojamos prognozės patikimumo indekso (RI) reikšmės. Tokia savybė yra vienas pagrindinių reikalavimų vertinant bet kokio modelio galimybes tapti ES oficialiai pripažintu alternatyviu tyrimo metodu. Aiški prognozių kokybės priklausomybė nuo jų patikimumo išraiškos taip pat suteikia galimybę modelio rezultatus suskaidyti į kokybines klases pagal apskaičiuotąsias RI reikšmes. Vienas iš tokios informacijos panaudojimo būdų siūlomų disertacijoje yra junginių prioritetizavimas prieš bet kokius eksperimentinius matavimus ir netgi pastarųjų skaičiaus potencialus sumažinimas. Disertacijoje taip pat išnagrinėta galimybė greitai bei efektyviai apmokyti gautuosius GALAS modelius naujais eksperimentiniais duomenimis, išplečiant jų pritaikomumo sritį. Ši esminė savybė radikaliai padidina nagrinėjamųjų modelių, paremtų viešai prieinamų duomenų rinkiniais, realaus praktinio panaudojimo farmacijos pramonėje galimybes.

A norma Brasileira NBR 6122/1996 - Projeto e Execução de Fundações utiliza o conceito de coeficiente de segurança global e parcial na verificação da segurança de fundações. Esta dissertação ressalta que essa verificação, utilizada na prática, é necessária, para que se atenda às exigências da norma, porém, não é suficiente para garantir a segurança de uma fundação. Pois, qualquer medida de segurança deve estar associada a uma determinada probabilidade de ruína. Neste contexto, apresenta-se nessa dissertação uma metodologia de verificação da segurança na qual, a escolha da carga admissível de um estaqueamento é baseada na probabilidade de ruína de um elemento isolado de fundação e, a aplicação dessa metodologia em diversas fundações executadas em diferentes regiões do país. / The Brazilian code NBR 6122/1996 for Foundation Design and Execution is based on the concept of Limit States Design (LSD) and on the traditional Working Stress Design (WSD). This paper shows that this approach, as usually carry out in the foundation engineering practice, although being necessary, is not enough to assure a safe foundation, once any safety measurement should be associated to a given probability of failure. Therefore, in the proposed methodology, the safety verification of the piling allowable load is based on the probability of failure of an isolated foundation element.

This thesis deals with the development of a complex methodology for probabilistic analysis of reliability and durability of reinforced concrete structures, especially road bridges. An estimation of load-bearing capacity is carried out using probabilistic methods in combination with the nonlinear finite element method analysis and also with respect to reliability requirements according to standards. The current state of the structure is taken into account based on the mathematical modeling of the degradation processes, such as concrete carbonation, chloride ingress and subsequent corrosion of reinforcement. Then the load-bearing capacity and reliability is predicted over time. Attention is focused on the upgrade of the analytical models for modeling of degradation processes with regard to the effect of mechanical load on the structure or its components, the development of an artificial neural network-based response surface method for efficient approximation of the original limit state function with respect to the accuracy and a minimization the number of simulations, and an interconnection of individual processes and advanced methods in an automatic process.

The interruption cost for one hour of a petrochemical plant is 33 times higher than that of the average interruption cost for industrial plants across all industries. In addition to the high cost of loss of production, interruptions to the operations of petrochemical and gas-toliquid plants pose safety and environmental hazards. Thus it is necessary to better understand the reliability requirements of petrochemical and gas-to-liquid plants. This study investigated the reliability of electrical distribution networks used in petrochemical and gas-to-liquid plants compared to those used in other industrial plants. A model was developed that can be used to establish the adequacy of the reliability of a distribution network in terms of the components and network topologies used. This model was validated against data that had been collected by the IEEE and applied to an actual petrochemical plant. Over 19 years’ worth of data regarding the trips that have occurred on the distribution network of an existing petrochemical plant was collected and manipulated in order to calculate the reliability indices associated with the equipment used to make up thisRecommended Practice for the Design of Reliable Industrial and Commercial Power Systems. The cost of loss of production and the capital costs associated with increased reliability were calculated for a section of the existing petrochemical plant. The reliability associated with different network topologies that could possibly be used to supply power to this section of the plant were modelled using an appropriate software package. The resulting total cost of ownership over the life of the plant associated with each topology was then calculated in order to establish which network topology is the most appropriate for petrochemical and gas-to-liquid plants. It was concluded the components that affect the reliability of an industrial distribution network are different to those that affect a utility distribution network. These components were listed and compared. It was found that the reliability indices that were calculated for the components that affect the reliability of a petrochemical plant were similar to those provided by the IEEE. 17 out of 20 of the indices that were calculated were within the required factor of deviation. Generally the failure rates of components used in petrochemical plants were very similar to those given in the IEEE Gold Book, while the MTTR’s for the components used in petrochemical plants were found to be slightly better than those given in the IEEE Gold Book. The effect of network topology was found to be significant, with small changes in the topology of a network resulting in large variations in the reliability of the network. It was also found that the most appropriate type of network topology to use in the design of the electrical distribution network of a petrochemical plant is the dual radial network. This is the most conservative of the commonly used network topologies and is the one that is currently used in the existing plant that was studied. Due to the high cost of loss of production in petrochemical plants it was established that any incremental improvement in the reliability of the dual radial network would be beneficial to the total cost of ownership of such a plant. Such incremental improvement of the reliability of the distribution network could be cost effectively achieved by adopting a conservative maintenance strategy and the establishment of a conservative spares inventory. Before this study was undertaken, there was no literature around the reliability of electrical distribution networks that focused specifically on petrochemical and gas-to-liquid plants. This study produced a set of reliability indices and a model that electrical engineers can use in the reliability analysis of petrochemical and gas-to-liquid plants. Furthermore it shows that, because the cost of loss of production in petrochemical plants is so high, the most conservative distribution network design and maintenance philosophies should always be used. distribution network. These reliability indices were compared to those given by the IEEE / Dissertation (MEng)--University of Pretoria, 2013. / gm2014 / Electrical, Electronic and Computer Engineering / unrestricted

With increasing age of the concrete road bridges, the highly topical question is to determine their reliability and load-bearing capacity level required for the residual life of the structure. Doctoral thesis presents a comprehensive methodology for assessing the reliability of reinforced and prestressed concrete bridges based on non-linear finite element method damage and failure virtual simulations at both deterministic and stochastic levels. Load-bearing capacity values are specified by the structure’s design load capacity estimation by global safety factor methods or they are based on a fully probabilistic load capacity analysis using the direct resistance estimation. For the fully probabilistic calculations, the simulation technique Latin Hypercube Sampling is used.

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