Shape Optimization of Turbomachinery Blade Using Multiple Surrogate Models

2006 ◽  
Author(s):  
Abdus Samad ◽  
Kwang-Yong Kim ◽  
Tushar Goel ◽  
Raphael T. Haftka ◽  
Wei Shyy
Keyword(s):  
Shape Optimization ◽  
Cost Benefit Analysis ◽  
Weighted Average ◽  
Cost Benefit ◽  
Network Models ◽  
Surrogate Models ◽  
Fractional Factorial ◽  
Neural Network Models ◽  
Optimal Point ◽  
Multiple Surrogate Models

Performances of multiple surrogate models are evaluated in a turbomachinery blade shape optimization. The basic models, i.e., Response Surface Approximation, Kriging and Radial Basis Neural Network models as well as weighted average models are tested for shape optimization. Global data based errors for each surrogates are used to calculate the weights. These weights are multiplied with the respective surrogates to get the final weighted average models. Sequential Quadratic Programming is used to search the optimal point from these constructed surrogates. Use of multiple surrogates via weighted averaged surrogates gives more robust approximation than individual surrogates. Three design variables are selected to enhance the performance of transonic axial compressor (NASA rotor 37) blade and the design points are selected using three level fractional factorial D-optimal designs. The performance of compressor is improved by optimization because of reduction of losses and movement of separation line towards down stream directions. The present approach can help address the multi-objective design on a rational basis with quantifiable cost-benefit analysis.

Laser Forming for Flexible Fabrication

2000 ◽  
Vol 16 (02) ◽  
pp. 97-109
Author(s):  
Koichi Masubuchi ◽  
Jerry E. Jones
Keyword(s):  
Three Dimensional ◽  
Low Carbon Steel ◽  
High Strength Steels ◽  
Cost Benefit ◽  
Network Models ◽  
High Strength ◽  
Laser Forming ◽  
Low Carbon ◽  
Flat Plates ◽  
Neural Network Models

A 36-month program supported by the Defense Advanced Research Projects Agency (DARPA) was conducted to demonstrate the feasibility to predictably laser form a variety of ferrous and non-ferrous metals of different thickness. Laser forming provides a method of producing complex shapes in sheet, plate, and tubing without the use of tooling, molds, or dies. By heating a localized area with a laser beam, it is possible to create stress states that result in predictable deformation. This research program has developed, refined and demonstrated constitutive and empirical, and neural network models to predict deformation as a function of critical parametric variables and established an understanding of the effect of laser forming on some metallurgical properties of materials. The program was organized into two, time-phased tasks. The first task involved forming flat plates to one-dimensional (I -D) shapes, such as, hinge bends in various materials including low-carbon steel, high-strength steels, nickel-based super alloys, and aluminum alloys. The second task expanded the work conducted in the first task to investigate three-dimensional (3-D) configurations. The models were updated, 3-D specimens fabricated and evaluated, and cost benefit analyses were performed.

scholarly journals Cost Benefit Analysis of Elastic and Mixed Line Rate Optical Network Models

2021 ◽  
Author(s):  
Reinhardt Rading
Keyword(s):  
Optical Networks ◽  
Cost Benefit Analysis ◽  
Optical Network ◽  
Cost Benefit ◽  
Network Models ◽  
Single Type ◽  
Bit Rate ◽  
Low Bit Rate ◽  
Mixed Line ◽  
Mixed Line Rate

<div>Network traffic continues to grow at more than 30 percent per year and we either have to install new optical infrastructures or upgrade our optical networks to meet the increasing demands. Installing new fibers seems very costly the network operators considering the heterogeneity of optical networks with some consumers requiring low bit rate and others requiring high bit rate demands. As an alternative, we can use the existing fiber infrastructure to meet the traffic demands by aggregating both high and low bit rate demands or using a single type of rate-tunable technology to handle the increasing demands. This paper analyzes the two planning strategies-all period planning and incremental planning- for allocating resources in an increasing traffic and shows the pros and cons that a network operator may experience in case of using either elastic or mixed line rate optical networks.</div>

Creating surrogate models for an air and missile defense simulation using design of experiments and neural networks

2019 ◽  
pp. 154851291987798
Author(s):  
Brian M Wade
Keyword(s):  
Design Of Experiments ◽  
Network Models ◽  
Surrogate Models ◽  
Cruise Missile ◽  
Missile Defense ◽  
Neural Network Models ◽  
Desktop Computer ◽  
Air Defense ◽  
The Mean ◽  
Cruise Missiles

This paper demonstrates a method of constructing multiple linked surrogate models of a high-fidelity air and missile defense simulation using design of experiments to generate labeled data for neural network models. The surrogate models are used to predict the number of incoming missiles destroyed and the number of interceptors launched from a multi-layered defense composed of three different air defense systems intercepting both ballistic and cruise missiles without the need for time intensive simulation runs. A single model that predicts all outcomes was first attempted, but was shown to have inadequate prediction capabilities. The working setup uses multiple surrogate models that are linked to allow information to pass between each model. The paper demonstrates how to develop the surrogate models using a notional example, and how to link these surrogate models together using time to impact for the missiles. The same methodology also allows the same surrogate model to switch between ballistic and cruise missile engagements. When run on a desktop computer, a 30 Monte Carlo set of the notional example took several minutes to complete; however, this proof of principal implementation of the surrogate models was able to predict the mean number missiles destroyed or the mean number of interceptors fired to within one missile nearly instantaneously.

scholarly journals Cost Benefit Analysis of Elastic and Mixed Line Rate Optical Network Models

2021 ◽  
Author(s):  
Reinhardt Rading
Keyword(s):  
Optical Networks ◽  
Cost Benefit Analysis ◽  
Optical Network ◽  
Cost Benefit ◽  
Network Models ◽  
Single Type ◽  
Bit Rate ◽  
Low Bit Rate ◽  
Mixed Line ◽  
Mixed Line Rate

<div>Network traffic continues to grow at more than 30 percent per year and we either have to install new optical infrastructures or upgrade our optical networks to meet the increasing demands. Installing new fibers seems very costly the network operators considering the heterogeneity of optical networks with some consumers requiring low bit rate and others requiring high bit rate demands. As an alternative, we can use the existing fiber infrastructure to meet the traffic demands by aggregating both high and low bit rate demands or using a single type of rate-tunable technology to handle the increasing demands. This paper analyzes the two planning strategies-all period planning and incremental planning- for allocating resources in an increasing traffic and shows the pros and cons that a network operator may experience in case of using either elastic or mixed line rate optical networks.</div>

The Use of Cost-Benefit Analysis for Evaluating Efficiency of Public Investment Projects (The Case of Sochi-2014 Winter Olympic Games)

2011 ◽  
pp. 57-78
Author(s):  
I. Pilipenko
Keyword(s):  
Net Present Value ◽  
Olympic Games ◽  
Cost Benefit Analysis ◽  
Public Investment ◽  
Cost Benefit ◽  
Investment Efficiency ◽  
Benefit Analysis ◽  
Step Method ◽  
Investment Projects ◽  
The Usa

The paper analyzes shortcomings of economic impact studies based mainly on input- output models that are often employed in Russia as well as abroad. Using studies about sport events in the USA and Olympic Games that took place during the last 30 years we reveal advantages of the cost-benefit analysis approach in obtaining unbiased assessments of public investments efficiency; the step-by-step method of cost-benefit analysis is presented in the paper as well. We employ the project of Sochi-2014 Winter Olympic and Paralympic Games in Russia to evaluate its efficiency using cost-benefit analysis for five accounts (areas of impact), namely government, households, environment, economic development, and social development, and calculate the net present value of the project taking into account its possible alternatives. In conclusion we suggest several policy directions that would enhance public investment efficiency within the Sochi-2014 Olympics.

Hostile Takeovers and Anti-takeover Defenses in the Russian Corporate Market

2007 ◽  
pp. 70-84 ◽  
Author(s):  
E. Demidova
Keyword(s):  
Cost Benefit Analysis ◽  
Cost Benefit ◽  
Benefit Analysis ◽  
Costs And Benefits ◽  
Hostile Takeovers ◽  
Russian Market ◽  
Takeover Defenses ◽  
The Cost ◽  
European Markets

This article analyzes definitions and the role of hostile takeovers at the Russian and European markets for corporate control. It develops the methodology of assessing the efficiency of anti-takeover defenses adapted to the conditions of the Russian market. The paper uses the cost-benefit analysis, where the costs and benefits of the pre-bid and post-bid defenses are compared.

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