Multi-objective optimization based engineering decision tool

Prior to the acceptance of computer aided engineering (CAE) software in the product development process (PDP), product development was characterized by a design-test-redesign-test cycle. This activity was time consuming and resource intensive. As CAE software tools have been integrated into the PDP, the PDP can be characterized by a design-simulate-redesign-test cycle. The addition of CAE tools to the PDP has reduced the time to market and resource consumption. In the last decade, CAE software has become easier to use and computer power has increased such that CAE software is more widely used in the PDP. In parallel, there has been a desire, in the last decade, to further reduce product development times and resource consumption. To achieve this next step in reduction of PDP time and resource consumption, the need for increased integration of CAE software earlier in the PDP is needed. This will provide the design engineer with increased design problem knowledge earlier in the PDP, which is when increased knowledge about the design problem is most valuable in the PDP timeline and can impact the product design the most. Design problems are characterized by having multiple solutions. The implication of this is that there are multiple acceptable solutions but there are few global optimum solutions. It is the design engineer\u27s chief aim to find the most optimum solution to the design problem at hand. Simply put, the aim of the method presented in this thesis is to integrate computational fluid dynamics (CFD) models earlier in the PDP to facilitate engineering decision making early in the PDP. In this thesis, a simulation workflow is demonstrated that connects computer aided design (CAD) software with CFD software, which is a CAE software, with both connected to a multi-objective optimization algorithm. This simulation workflow is used to generate a Pareto-optimal set of designs, sometimes called non-dominant, set of designs. The design problem is represented in the CAD software with the geometric design variables explicitly defined in the CAD representation of the design problem. The CFD software is used to calculate the performance objectives of the design solution. The multi-objective optimization algorithm evaluates the performance of the design solution and chooses new design variable values for use in the CAD representation. This process continues until the Pareto-optimal set of designs is identified. This is the Level-1 optimization of the overall framework presented in this thesis. The Level-2 optimization consists of an algorithm that operates on the Pareto-optimal set of designs identified in the Level-1 optimization. The algorithm presents the user with a number of designs from the Pareto-optimal set. The user chooses the best design solution from the design solutions shown based on higher-level, qualitative information. This continues until all of the Pareto-optimal designs have been evaluated or the user terminates the process. This simulation flow facilitates using CAE software, specifically CFD, earlier in the PDP which leads to simulation based design. This maximizes design problem knowledge earlier in the PDP, reduces the PDP time, and reduces the resources required to develop a new product

The effect of performance stages on subwoofer polar and frequency responses

Precise control of low-frequency energy is a common requirement at large-scale live events, whereby sound energy transmitted into performance areas and outside event grounds must be limited. Industry-standard sound system design and prediction software typically omits any acoustical effect a performance stage will have on the overall system response (both in terms of polar and frequency response).This research highlights the significant effect a stage can have on subwoofer performance, where in particularly poor cases directionality is lost and the frequency response is strongly colored by resonances. This work puts forward recommendations for subwoofer system configurations that avoid unwanted stage effects as much as possible to maintain the desired (and predicted) system performance

A viewer for PostScript documents

We describe a PostScript viewer that provides navigation and annotation functionality similar to that of paper documents using simple unified user-interface techniques.Engineering and Applied Science

Measurement and Calibration of Noise Bias in Weak Lensing Galaxy Shape Estimation

Weak gravitational lensing has the potential to constrain cosmological parameters to high precision. However, as shown by the Shear TEsting Programmes (STEP) and GRavitational lEnsing Accuracy Testing (GREAT) Challenges, measuring galaxy shears is a nontrivial task: various methods introduce different systematic biases which have to be accounted for. We investigate how pixel noise on the image affects the bias on shear estimates from a Maximum-Likelihood forward model-fitting approach using a sum of co-elliptical S\'{e}rsic profiles, in complement to the theoretical approach of an an associated paper. We evaluate the bias using a simple but realistic galaxy model and find that the effects of noise alone can cause biases of order 1-10% on measured shears, which is significant for current and future lensing surveys. We evaluate a simulation-based calibration method to create a bias model as a function of galaxy properties and observing conditions. This model is then used to correct the simulated measurements. We demonstrate that this method can effectively reduce noise bias so that shear measurement reaches the level of accuracy required for estimating cosmic shear in upcoming lensing surveys.Comment: 12 pages, 4 figures, submitted to MNRA

Full color two-loop six-gluon all-plus helicity amplitude

We present the full color two-loop six-point all-plus Yang-Mills amplitude in compact analyticform. The computation uses four dimensional unitarity and augmented recursion

Sun Tzu and The Art of Healing: Executive Dashboards and Data Mining for Business Intelligence in Integrated, Lean Military Medical Supply Logistics for the 21st Century

The combined Air Force, Army, and Navy Surgeons General are now achieving integrated oversight of their medical supplies and resources. This allows a Business Intelligence approach to decisions which is now being enhanced with real-time interactive data-mining tools and executive dashboards. Resources can be efficiently reallocated to military, veteran, family, or civilian purposes, inventories can be maintained at lean levels, and peak demands can be managed with executive dashboards to reduce overload and errors

Building Environmentally Sustainable Communities: A Framework for Inclusivity

Reviews literature on past inequitable and unsustainable urban development and visions for linking sustainability, opportunity, and inclusion. Analyzes possible metrics for measuring sustainability and access as well as next steps for policy