Sustainable production and consumption have become more important internationally, which has led to the transformation of market structures and competitive situations into the direction of servitisation. This means that manufacturing companies are forced to compete through the supply of services as opposed to products. Particularly the suppliers of long-life products such as submarines and airplanes no longer simply sell these products but provide their capability or availability. Companies such as Rolls-Royce Engines achieve 60% of their revenue through selling a service rather than the engine itself. For a manufacturing company, the shift towards being a service provider means that they usually have to bid for service contracts, sometimes competitively. In the context of competitive bidding, the decision makers face various uncertainties that influence their decision. Ignoring these uncertainties or their influences can result in problems such as the generation of too little profit or even a loss or the exposure to financial risks. Raising the decision maker’s awareness of the uncertainties in the form of e.g. a decision matrix, expressing the trade-off between the probability of winning the contract and the probability of making a profit, aims at integrating these factors in the decision process. The outcome is to enable the bidding company to make a more informed decision. This was the focus of the research presented in this thesis. The aim of this research was to support the pricing decision by defining a process for modelling the influencing uncertainties and including them in a decision matrix depicting the trade-off between the probability of winning the contract and the probability of making a profit. Three empirical studies are described and the associated decision process and influencing uncertainties are discussed. Based on these studies, a conceptual framework was defined which depicts the influencing factors on a pricing decision at the bidding stage and the uncertainties within these. The framework was validated with a case study in contract bidding where the uncertainties were modelled and included in a decision matrix depicting the probability of winning the contract and the probability of making a profit. The main contributions of this research are the identification of the uncertainties influencing a pricing decision, the depiction of these in a conceptual framework, a method for ascertaining how to model these uncertainties and assessing the use of such an approach via an industrial case study.

The optimal replacement policy for an asset subject to a stochastic deteriorating operating cost is determined for three different tax depreciation schedules and a known re-investment cost, as the solution to a two-factor model using a quasi-analytical method. We find that tax depreciation exerts a critical influence over the replacement policy by lowering the operating cost thresholds. Although typically a decline in the corporate tax rate, increase in any initial capital allowance, or decrease in the depreciation lifetime (increase in depreciation rate) results in a lower operating cost threshold which justifies replacing older equipment, these results are not universal, and indeed for younger age assets the result may be the opposite. An accelerating depreciation schedule may incentivize early replacement in a deterministic context, but not necessarily for an environment of uncertainty.

As a special case of the static state estimation problem, the load-flow problem is studied in this thesis. It is demonstrated that the non-linear load-flow formulation may be solved by real-coded genetic algorithms. Due to its global optimisation ability, the proposed method can be useful for off-line studies where multiple solutions are suspected. This thesis presents two methods for estimating the uncertainty interval in power system state estimation due to uncertainty in the measurements. The proposed formulations are based on a parametric approach which takes in account the meter inaccuracies. A nonlinear and a linear formulation are proposed to estimate the tightest possible upper and lower bounds on the states. The uncertainty analysis, in power system state estimation, is also extended to other physical quantities such as the network parameters. The uncertainty is then assumed to be present in both measurements and network parameters. To find the tightest possible upper and lower bounds of any state variable, the problem is solved by a Sequential Quadratic Programming (SQP) technique. A new robust estimator based on the concept of uncertainty in the measurements is developed here. This estimator is known as Maximum Constraints Satisfaction (MCS). Robustness and performance of the proposed estimator is analysed via simulation of simple regression examples, D.C. and A.C. power system models.

Yes / In this paper, a stochastic approach for the operation of active distribution networks within a joint active and reactive distribution market environment is proposed. The method maximizes the social welfare using market based active and reactive optimal power flow (OPF) subject to network constraints with integration of demand response (DR). Scenario-Tree technique is employed to model the uncertainties associated with solar irradiance, wind speed and load demands. It further investigates the impact of solar and wind power penetration on the active and reactive distribution locational prices (D-LMPs) within the distribution market environment. A mixed-integer linear programming (MILP) is used to recast the proposed model, which is solvable using efficient off-the shelf branch-and cut solvers. The 16-bus UK generic distribution system is demonstrated in this work to evaluate the effectiveness of the proposed method. Results show that DR integration leads to increase in the social welfare and total dispatched active and reactive power and consequently decrease in active and reactive D-LMPs. / Ministry of Higher Education and Scientific Research of Iraq

Yes / In this paper, a stochastic method is proposed to assess the amount of active and reactive power that can be injected/absorbed to/from grid within a distribution market environment. Also, the impact of wind power penetration on the reactive and active distribution-locational marginal prices is investigated. Market-based active and reactive optimal power flow is used to maximize the social welfare considering uncertainties related to wind speed and load demand. The uncertainties are modeled by Scenario-based approach. The proposed model is examined with 16-bus UK generic distribution system. / Supported by the Higher Education Ministry of Iraqi government.

Autonomous visual navigation algorithms for ground mobile robotic systems working in unstructured environments have been extensively studied for decades. Among these work, algorithm performance evaluations between different design configurations mainly involve the use of benchmark datasets with a limited number of real-world trails. Such evaluations, however, have difficulties to provide sufficient statistical power for performance quantification. In addition, they are unable to independently assess the algorithm robustness to individual realistic uncertainty sources, including the environment variations and processing errors. This research presents a quantitative approach to performance and robustness evaluation and optimisation of autonomous visual navigation algorithms, using large scale Monte-Carlo analyses. The Monte-Carlo analyses are supported by a simulation environment designed to represent a real-world level of visual information, using the perturbations from realistic visual uncertainties and processing errors. With the proposed evaluation method, a stereo vision based autonomous visual navigation algorithm is designed and iteratively optimised. This algorithm encodes edge-based 3D patterns into a topological map, and use them for the subsequent global localisation and navigation. An evaluation on the performance perturbations from individual uncertainty sources indicates that the stereo match error produces significant limitation for the current system design. Therefore, an optimisation approach is proposed to mitigate such an error. This maximises the Fisher information available in stereo image pairs by manipulating the stereo geometry. Moreover, the simulation environment is further updated in association with the algorithm design, which include the quantitative modelling and simulation of localisation error to the subsequent navigation behaviour. During a long-term Monte-Carlo evaluation and optimisation, the algorithm performance has been significantly improved. Simulation experiments demonstrate that the navigation of a 3-DoF robotic system is achieved in an unstructured environment, while possessing sufficient robustness to realistic visual uncertainty sources and systematic processing errors.

Methods for uncertainty quantification (UQ) and mitigation in the electrical power system are very basic, Monte Carlo (MC) method and its meta methods are generally deployed in most applications, due to its simplicity and easy to be generalised. They are adequate for a traditional power system when the load is predictable, and generation is controllable. However, the large penetration of low carbon technologies, such as solar panels, electric vehicles, and energy storage, has necessitated the needs for more comprehensive approaches to uncertainty as these technologies introduce new sources of uncertainties with larger volume and diverse characteristics, understanding source and consequences of uncertainty becomes highly complex issues. Traditional methods assume that for a given system it has a unique uncertainty characteristic, hence deal with the uncertainty of the system as a single component in applications. However, this view is no longer applicable in the new context as it neglects the important underlying information associated with individual uncertainty components. Therefore, this thesis aims at: i) systematically developing UQ methodologies to identify, discriminate, and quantify different uncertainty components (forward UQ), and critically to model and trace the associated sources independently (inverse UQ) to deliver new uncertainty information, such as, how uncertainty components generated from its sources, how uncertainty components correlate with each other and how uncertainty components propagate through system aggregation; ii) applying the new uncertainty information to further improve a range of fundamental power system applications from Load Forecasting (LF) to Energy Management System (EMS).In the EMS application, the proposed forward UQ methods enable the development of a decentralised system that is able to tap into the new uncertainty information concerning the correlations between load pattern across individual households, the characteristics of uncertainty components and their propagation through aggregation. The decentralised EMS was able to achieve peak and uncertainty reduction by 18% and 45% accordingly at the grid level. In the LF application, this thesis developed inverse UQ through a deep learning model to directly build the connection between uncertainty components and its corresponding sources. For Load Forecasting on expectation (point LF) and probability (probabilistic LF) and witnessed 20%/12% performance improvement compared to the state-of-the-art, such as Support Vector Regression (SVR), Autoregressive Integrated Moving Average (ARIMA), and Multiple Linear Quantile Regression (MLQR).

This doctoral thesis investigates the application of simulation-based optimization (SBO) as an alternative to conventional optimization techniques when the inherent uncertainty and complex features of real manufacturing systems need to be considered. Inspired by a real-world production planning setting, we provide a general formulation of the situation as an extended knapsack problem. We proceed by proposing a solution approach based on single and multi-objective SBO models, which use simulation to capture the uncertainty and complexity of the manufacturing system and employ meta-heuristic optimizers to search for near-optimal solutions. Moreover, we consider the design of matheuristic approaches that combine the advantages of population-based meta-heuristics with mathematical programming techniques. More specifically, we consider the integration of mathematical programming techniques during the initialization stage of the single and multi-objective approaches as well as during the actual search process. Using data collected from a manufacturing company, we provide evidence for the advantages of our approaches over conventional methods (integer linear programming and chance-constrained programming) and highlight the synergies resulting from the combination of simulation, meta-heuristics and mathematical programming methods. In the context of the same real-world problem, we also analyse different single and multi-objective SBO models for robust optimization. We demonstrate that the choice of robustness measure and the sample size used during fitness evaluation are crucial considerations in designing an effective multi-objective model.

The advanced handling of uncertainties arising from a wide range of sources is fundamental in quality control and dependability to reach advantageous decisions in different organizational levels of industry. Es-pecially in the competitive edge of production, uncertainty shall not be solely object of estimation but the result of a systematic management process. In this process, the composition and utilization of proper in-formation acquisition systems, capability models and propagation tools play an inevitable role. This thesis presents solutions from production system to operational level, following principles of the introduced con-cept of uncertainty-based thinking in production. The overall aim is to support transparency, predictability and reliability of production sys-tems, by taking advantage of expressed technical uncertainties. On a higher system level, the management of uncertainty in the quality con-trol of industrial processes is discussed. The target is the selection of the optimal level of uncertainty in production processes integrated with measuring systems. On an operational level, a model-based solution is introduced using homogeneous transformation matrices in combination with Monte Carlo method to represent uncertainty related to machin-ing system capability. Measurement information on machining systems can significantly support decision-making to draw conclusions on man-ufactured parts accuracy, by developing understanding of root-causes of quality loss and providing optimization aspects for process planning and maintenance. / <p>QC 20181015</p>

Les roues aubagées de turbomachines sont soumises en fonctionnement `a des sollicitations statiqueset dynamiques, qui peuvent conduire `a des situations de fatigue vibratoire pour des excitationsau voisinage des fréquences de résonance. Ce probléme est aggravé par le désaccordage involontaire,auquel sont sujets les ensembles aubagés notamment du fait des dispersions de fabrication.L’objectif de ce travail de recherche est de proposer une stratégie mixte numérique et expérimentalepermettant de caractériser le comportement dynamique d’une roue d’essai au sein des statistiquesdécrivant une flotte simulée de moteurs en service, en vue de la certification vibratoire. Un modèle numérique fidèle basée sur l’acquisition optique d’une roue expérimentale a été développé; une série d’essais en laboratoire a permis de vérifier sa représentativité. L’exploitation de mesures réalisées en configuration moteur a montré une bonne cohérence globale des niveaux d’amplitude prédits à l’aidedu modèle fidèle. Enfin, la simulation du comportement d’une population de roues désaccordées à l’aide d’une approche probabiliste non-Paramétrique a permis de positionner l’amplitude de réponse maximale rencontrée sur la pièce d’essai par rapport à la valeur théorique obtenue par simulation. La stratégie proposée permet une prédiction des niveaux vibratoires maximaux pour une flotte de rouesen service. / Under operating conditions, turbomachinery blisks are subject to static and dynamic loads which mayresult in High-Cycle Fatigue situations when excited at the neighbourhood of resonant frequencies.Random mistuning, which affects blisks due to machining deviations, turns this issue even morecritical. The objective of the current study is to introduce a numerical-Experimental strategy allowingthe dynamic characterization of an experimental bladed disk with regard to the statistics representingthe simulated behaviour for a population of operating blisks. A high-Fidelity numerical model basedon the optical acquisition of an experimental blisk has been set up. Test series performed in labconditions allowed to verify its coherence. The comparison of the response amplitudes measuredunder operating conditions to the model predictions revealed an acceptable matching between testand simulation data. Finally, a non-Parametric probabilistic approach has been used to predict thetheoretical maximal amplification factor. The maximum amplification factor obtained by means ofsimulation was compared to the amplification factor of the test specimen. The strategy proposed inthis study allows maximum amplification factor predictions for a population of blisks