An Investigation into Subject Matter Expert Elicitation in Cost Risk Analysis

This research compares the efficacy of subject matter expert (SME) elicitation methods to other cost estimation methods using a development and production dataset provided by AFLCMC/FZC. First, by using descriptive statistics to evaluate low versus high amount of the respective cost estimation methods by analyzing the means of percent cost growth for both groups. Next, this research involved using a statistics-based approach to investigate whether SME based cost estimating methods have an associated relationship to percent change of Program Acquisition Unit Costs (PAUC), which will be our proxy variable to cost growth. Using a pooled cross-sectional OLS regression analysis model with adjusted R2 of 0.298, 144 POEs sample for development have statistical evidence to support SME based cost estimates have a positive association with Program Acquisition Unit Cost (PAUC). Lastly, this research critically examines SME elicitation methods used within DoD and provides best practices used by industry and academia when eliciting SMEs that the cost estimating community should consider implementing

Conformal Predictions Enhanced Expert-guided Meshing with Graph Neural Networks

Computational Fluid Dynamics (CFD) is widely used in different engineering fields, but accurate simulations are dependent upon proper meshing of the simulation domain. While highly refined meshes may ensure precision, they come with high computational costs. Similarly, adaptive remeshing techniques require multiple simulations and come at a great computational cost. This means that the meshing process is reliant upon expert knowledge and years of experience. Automating mesh generation can save significant time and effort and lead to a faster and more efficient design process. This paper presents a machine learning-based scheme that utilizes Graph Neural Networks (GNN) and expert guidance to automatically generate CFD meshes for aircraft models. In this work, we introduce a new 3D segmentation algorithm that outperforms two state-of-the-art models, PointNet++ and PointMLP, for surface classification. We also present a novel approach to project predictions from 3D mesh segmentation models to CAD surfaces using the conformal predictions method, which provides marginal statistical guarantees and robust uncertainty quantification and handling. We demonstrate that the addition of conformal predictions effectively enables the model to avoid under-refinement, hence failure, in CFD meshing even for weak and less accurate models. Finally, we demonstrate the efficacy of our approach through a real-world case study that demonstrates that our automatically generated mesh is comparable in quality to expert-generated meshes and enables the solver to converge and produce accurate results. Furthermore, we compare our approach to the alternative of adaptive remeshing in the same case study and find that our method is 5 times faster in the overall process of simulation. The code and data for this project are made publicly available at https://github.com/ahnobari/AutoSurf

The role of information systems in decision-making biases

Information systems and in particular decision support systems have been developed to supplement human information processing and to assist with decision-making. Human decision-making is facilitated by the often unconscious use of heuristics or rules of thumb in situations where it may not be possible or feasible to search for the best decision. Judgemental heuristics have previously been found to lead to biases in decision-making. When information systems are used as decision aids, they may have an influence on biases. This study investigates the possible role of information systems in introducing, reinforcing or reducing biases of decision-making. It has been found that information systems have the ability to introduce new biases and to reinforce biases. Information systems can also reduce biases, but this requires innovate thinking on the way information is represented and the way human decision-making processes are supported. It has also been found that in the real world, other than the laboratories where biases are usually measured, other constraints on rational decision-making, such as politics or data errors, can overshadow the effects of biases.Dissertation (MPhil)--University of Pretoria, 2003.Informaticsunrestricte

The application of expert systems in parenteral nutrition

Total Parenteral Nutrition (TPN) is a medical technique used to provide a patient\u27s nutritional requirements via intravenous feeding. Critically ill patients must have adequate nutrition but must also have a stable physiology compensated for or treated by drugs. Several factors such as the complex nature of the TPN solution, the cost of the ingredients and the possible interaction of nutrient and drugs has led to the development of small expert system to assist the hospital medical staff in formulating the TPN constituents and assist the pharmacy staff in producing the final solution. This text will describe a small knowledge-based diagnostic system which when combined with conventional programming techniques has led to tangible benefits within a hospital Intensive Care Unit and Pharmacy

Uncertainty in Quantitative Risk Analysis - Characterisation and Methods of Treatment

The fundamental problems related to uncertainty in quantitative risk analyses, used in decision making in safety-related issues (for instance, in land use planning and licensing procedures for hazardous establishments and activities) are presented and discussed, together with the different types of uncertainty that are introduced in the various stages of an analysis. A survey of methods for the practical treatment of uncertainty, with emphasis on the kind of information that is needed for the different methods, and the kind of results they produce, is also presented. Furthermore, a thorough discussion of the arguments for and against each of the methods is given, and of different levels of treatment based on the problem under consideration. Recommendations for future research and standardisation efforts are proposed

Working Notes from the 1992 AAAI Spring Symposium on Practical Approaches to Scheduling and Planning

The symposium presented issues involved in the development of scheduling systems that can deal with resource and time limitations. To qualify, a system must be implemented and tested to some degree on non-trivial problems (ideally, on real-world problems). However, a system need not be fully deployed to qualify. Systems that schedule actions in terms of metric time constraints typically represent and reason about an external numeric clock or calendar and can be contrasted with those systems that represent time purely symbolically. The following topics are discussed: integrating planning and scheduling; integrating symbolic goals and numerical utilities; managing uncertainty; incremental rescheduling; managing limited computation time; anytime scheduling and planning algorithms, systems; dependency analysis and schedule reuse; management of schedule and plan execution; and incorporation of discrete event techniques

An analysis of the application of AI to the development of intelligent aids for flight crew tasks

This report presents the results of a study aimed at developing a basis for applying artificial intelligence to the flight deck environment of commercial transport aircraft. In particular, the study was comprised of four tasks: (1) analysis of flight crew tasks, (2) survey of the state-of-the-art of relevant artificial intelligence areas, (3) identification of human factors issues relevant to intelligent cockpit aids, and (4) identification of artificial intelligence areas requiring further research

Design and implementation of fuzzy logic controllers

The main objectives of our research are to present a self-contained overview of fuzzy sets and fuzzy logic, develop a methodology for control system design using fuzzy logic controllers, and to design and implement a fuzzy logic controller for a real system. We first present the fundamental concepts of fuzzy sets and fuzzy logic. Fuzzy sets and basic fuzzy operations are defined. In addition, for control systems, it is important to understand the concepts of linguistic values, term sets, fuzzy rule base, inference methods, and defuzzification methods. Second, we introduce a four-step fuzzy logic control system design procedure. The design procedure is illustrated via four examples, showing the capabilities and robustness of fuzzy logic control systems. This is followed by a tuning procedure that we developed from our design experience. Third, we present two Lyapunov based techniques for stability analysis. Finally, we present our design and implementation of a fuzzy logic controller for a linear actuator to be used to control the direction of the Free Flight Rotorcraft Research Vehicle at LaRC

Behavioral Economics and the Economics of Regulation

Behavioural economics draws upon fieldwork, experiments and research in disciplines such as psychology for building blocks to construct economic analysis that is more descriptively realistic and both augments and qualifies traditional economics as a tool for designing policy. Though behavioural economics has attracted much attention and respectability in the past decade or so, its roots date back to work undertaken in Europe a century ago and in the US in the middle of the twentieth century. Whereas economists traditionally have seen choice as an optimising activity subject to given preferences and a well-defined budget constraint, behavioural economics sees everyday life as a process in which humans with limited cognitive capacity try to cope with both information overload and the absence of relevant information and knowledge by evolving targets for what seems feasible and systems of rules for trying to find ways of meeting these targets. Some decision rules may be fast and frugal means of arriving at choices that do not result in needlessly poor attainments. However, much of what is known about how people actually behave implies that many people could be doing a lot better for themselves in many situations if only they were aware of the limitations of their ways of coping with the world and were motivated to find and apply improved decision rules. Poor search strategies limit the competitive pressures faced by firms and hence may have longer-term impacts on welfare via reduced productivity growth or innovation. However, in designing policies to promote better search by consumers one must remember that many consumers are also workers: higher productivity and better or cheaper goods may sometimes come at the cost of people having to work harder. To the extent that firms are aware of shortcomings of consumers' decision-making processes, they may be in a position to apply this knowledge to manipulate choices, for example by how they frame information that is presented to consumers. Tendencies for consumers to lack self-control and to fail to reflect on the longer-term implications of their choices can very easily result in poor choices when credit is easily available. Regulatory policies could do more to promote careful reflection by consumer by erecting hurdles to delay choice, as well as by measures to make it easier for consumers to make comparisons and see the financial implications of particular choices. In designing such policies there is scope for integrating them with policies aimed at the promotion of self-funded retirement and environmental wellbeing. The paper ends with detailed case study discussions of problems of choice in the markets for building renovation services and financial services. In the former, problems of finding good value for money are increased by the one-off nature of much of the work and by combination of shortages of trades-people relative to demand and large numbers of potential suppliers to approach for quotations. The environment is also conducive to consumers ending up overcapitalising in their renovations. In the market for financial services, the balance of risk-taking with property speculation and suchlike is stacked in favour of the loan providers, whilst the chances of inexperienced speculators getting into difficulties are enhanced because they are prone to use decision rules they have picked up from others belatedly and in simplified form. The implications of borrowing and superannuation choices should be made much more transparent to consumers, along with the futility of trying to beat the market rather than investing in market index funds