A Simulation-Based Robust Concept Exploration Method

2010 ◽  
Author(s):  
Markus Rippel ◽  
Seung-Kyum Choi ◽  
Farrokh Mistree ◽  
Janet K. Allen
Keyword(s):  
Response Surface ◽  
Design Space ◽  
Global Response ◽  
Response Models ◽  
Engineering Design Process ◽  
Simulation Based ◽  
Concept Exploration ◽  
Feasible Range ◽  
Design Requirements ◽  
Very High

In early stages of the engineering design process it is necessary to explore the design space to find a feasible range or point that satisfies the design requirements. When robustness of the system is among the requirements, the Robust Concept Exploration Method (RCEM) can be used. In RCEM a metamodel such as a global response surface of the entire design space is used. Based on this surrogate model the robustness of the system is evaluated. In nonlinear or multimodal design spaces a very detailed metamodel such as a very high order response surface might be required to reflect accurately the characteristics of the model. For large design spaces this is computationally very expensive. In this paper, using the Probabilistic Collocation Method (PCM) for generating local response models at the points of interest, a Simulation-Based RCEM is proposed as a very efficient and flexible robust concept exploration method. We believe that using the PCM with other design exploration methods would be equally effective.

Self-Perceived Creativity

2009 ◽  
Vol 25 (3) ◽  
pp. 194-203 ◽  
Author(s):  
Shulamith Kreitler ◽  
Hernan Casakin
Keyword(s):  
The Self ◽  
Experimental Task ◽  
Self Assessment ◽  
Specific Domain ◽  
Specific Product ◽  
Domain Specific ◽  
Design Representation ◽  
Design Requirements ◽  
Small Museum ◽  
Very High

In view of unclear previous findings about the validity of self-assessed creativity, the hypothesis guiding the present study was that validity would be proven if self-assessed creativity was examined with respect to a specific domain, specific product, specific aspects of creativity, and in terms of specific criteria. The participants were 52 architecture students. The experimental task was to design a small museum in a described context. After completing the task, the students self-assessed their creativity in designing with seven open-ended questions, the Self-Assessment of Creative Design questionnaire, and a list of seven items tapping affective metacognitive aspects of the designing process. Thus, 21 creativity indicators were formed. Four expert architects, working independently, assessed the designs on nine creativity indicators: fluency, flexibility, elaboration, functionality, innovation, fulfilling specified design requirements, considering context, mastery of skills concerning the esthetics of the design representation, and overall creativity. The agreement among the architects’ evaluations was very high. The correlations between the nine corresponding indicators in students’ assessment of their design and those of the experts were positive and significant with respect to three indicators: fluency, flexibility, and overall creativity. On the contrary, the correlations of the rest noncorresponding indicators with those of the experts were not significant. The findings support the validity of self-assessed creativity with specific restrictions.

Viterbi Decoder in Hardware

2018 ◽  
pp. 6307-6318
Author(s):  
Mário Pereira Véstias
Keyword(s):  
Maximum Likelihood ◽  
Viterbi Algorithm ◽  
Viterbi Decoder ◽  
Maximum Likelihood Decoding ◽  
High Data ◽  
Design Requirements ◽  
Trellis Decoding ◽  
And Performance ◽  
Viterbi Decoders ◽  
Very High

Trellis decoding is used to recover encoded information that was corrupted during transmission over a noisy channel. The Viterbi algorithm is the most well known trellis-based maximum likelihood decoding algorithm. The Viterbi algorithm is executed by a Viterbi decoder. Different hardware solutions may be considered to implement a Viterbi decoder with different design requirements in terms of area, performance, power consumption, among others. The most appropriate solution depends on the metric requirements of the application as well as on the target technology. Properties of the Viterbi algorithm are used to simplify and improve the architecture of the Viterbi decoder. In particular, statistical properties of the Viterbi algorithm are used to design parallel Viterbi decoders with very high data decoding rates. The article focuses on the implementation of a Viterbi decoder in hardware, including optimizations to improve the area and performance.

Adjoint-Response Surface Method in Aerodynamic Shape Optimization of Turbomachinery Blades

2016 ◽  
Author(s):  
Xiao Tang ◽  
Jiaqi Luo ◽  
Feng Liu
Keyword(s):  
Cost Function ◽  
Response Surface ◽  
Response Surface Method ◽  
Design Space ◽  
Three Dimensional ◽  
Gradient Methods ◽  
Control Parameters ◽  
Surface Method ◽  
Optimization Stage ◽  
Turbomachinery Blades

An adjoint-response surface method is developed to give global representation of cost function in a parametrized design space for turbomachinery blades. Radial basis function (RBF) based and quadratic polynomial (QP) based response surface models are constructed using both the values of cost function and its adjoint gradients with respect to geometry control parameters. The method is tested on a quasi-three dimensional NACA0012 blade row, then applied to the transonic Rotor 67. In preliminary design optimization stage, when the number of undetermined control parameters is large, the QP based model can provide a global image of the cost function in high dimensional design space with a small amount of sample points. In two-parameter fine optimization stage, high resolution can be achieved with the RBF based models. This gradient-enhanced response surface method is useful in guiding designers to discover the global optimum which may be missed by local gradient methods in a complicated design space. It may also be used as substitute of CFD flow solver in time consuming iterative design and optimization.

The Application of Response Surface Methodology for Adsorption Optimization of Lead (II) onto Phosphogypusum

2014 ◽  
Vol 955-959 ◽  
pp. 2026-2031
Author(s):  
Ping Ning ◽  
Yue Hong Yang ◽  
Dun Tao Shu ◽  
Lei Shi ◽  
Yang Cheng
Keyword(s):  
Response Surface ◽  
Polynomial Regression ◽  
Design Matrix ◽  
Box Behnken Design ◽  
Initial Concentration ◽  
Concentration Of Ions ◽  
Pb Ions ◽  
Optimized Conditions ◽  
Very High ◽  
Adsorbent Dose

Using the phosphogypsum as adsorbent prepared from microwave modified for the removal of lead ions from aqueous solution has been investigated under optimized conditions in this study. Influences of parameters like adsorbent dose 0.5-1.5g/100mL, initial concentration of ions 20–60 mg/L , pH 5.0–7.0 and temperature 20–30°C on Pb ions adsorption were also examined, using Box-Behnken design matrix. Very high regression coefficient between the variables and the response indicates excellent evaluation of experimental data by second order polynomial regression model. The response surface method indicated that adsorbent dose 1.0g/100mL, initial concentration of ions 40mg/L , pH 7.0 and temperature 20°C were optimal for adsorption of Pb ions .

scholarly journals Use of Response Surface Metamodels for Identification of Stiffness and Damping Coefficients in a Simple Dynamic System

2005 ◽  
Vol 12 (5) ◽  
pp. 317-331 ◽  
Author(s):  
A.C. Rutherford ◽  
D.J. Inman ◽  
G. Park ◽  
F.M. Hemez
Keyword(s):  
Parameter Identification ◽  
Response Surface ◽  
Structural Dynamics ◽  
Design Space ◽  
Ease Of Use ◽  
Surface Model ◽  
Training Requirements ◽  
System Parameters ◽  
Polynomial Response Surface ◽  
Stiffness And Damping

Metamodels have been used with success in many areas of engineering for decades but only recently in the field of structural dynamics. A metamodel is a fast running surrogate that is typically used to aid an analyst or test engineer in the fast and efficient exploration of the design space. Response surface metamodels are used in this work to perform parameter identification of a simple five degree of freedom system, motivated by their low training requirements and ease of use. In structural dynamics applications, response surface metamodels have been utilized in a forward sense, for activities such as sensitivity analysis or uncertainty quantification. In this study a polynomial response surface model is developed, relating system parameters to measurable output features. Once this relationship is established, the response surface is used in an inverse sense to identify system parameters from measured output features.A design of experiments is utilized to choose points, representing a fraction of the full design space of interest, for fitting the response surface metamodel. Two parameters commonly used to characterize damage in a structural system, stiffness and damping, are identified. First changes are identified and located with success in a linear 5DOF system. Then parameter identification is attempted with a nonlinear 5DOF system and limited success is achieved. This work will demonstrate that use of response surface metamodels in an inverse sense shows promise for use in system parameter identification for both linear and weakly nonlinear systems and that the method has potential for use in damage identification applications.

Noise Analysis of Silicon Microgyroscope's Transimpedance Amplifier Interface Circuit

2015 ◽  
Vol 645-646 ◽  
pp. 624-629
Author(s):  
Wei Feng Tang ◽  
An Ping Qiu ◽  
Guo Ming Xia ◽  
Yan Su
Keyword(s):  
Thermal Noise ◽  
Noise Analysis ◽  
Transimpedance Amplifier ◽  
Frequency Range ◽  
Output Current ◽  
Interface Circuit ◽  
Dc Offset ◽  
Simulation Based ◽  
Noise Density ◽  
Very High

The output-current of silicon microgyroscope is at the level of 10-7A. So the requirements for circuits’ SNR are very high. This paper proposes a method to improve transimpedance amplifier interface circuit’s SNR. First of all, the operating principles of silicon microgyroscope and transimpedance amplifier interface circuit are introduced. Secondly, resistor thermal noise, amplifier’s current and voltage noise are analyzed. Then noise density in a certain frequency range is calculated based on Matlab. Besides, a method to improve SNR is proposed, namely, increasing the value of DC offset resistance. Finally, simulation based on Cadence is operated to verify the method. Simulation results fit well with the theoretical analysis. That means the method to improve the SNR is feasible.

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