Planning on Mistakes: An Approach to Incorporate Error Checking Into the Design Process

2008 ◽  
Author(s):  
Erich Devendorf ◽  
Kemper Lewis
Keyword(s):  
Case Studies ◽  
Design Process ◽  
Optimization Problem ◽  
Theoretical Design ◽  
Design Variables ◽  
Error Check ◽  
Error Checking ◽  
Time Required ◽  
The Cost ◽  
Future Work

Mistakes in the design process have been recognized as a major source of product quality loss. There are several methods currently used to identify and quantify these mistakes. However, these methods typically do not provide a useful context within which to quantitatively incorporate mistakes into the design process in a beneficial way. This paper presents an approach to determine when it is appropriate to perform error checking to eliminate a potential mistake. The proposed approach is intended to be used when time is a limited design resource and design goals are technically attainable. It is proposed that the cost of a mistake can be quantified as the amount of time a mistake adds or subtracts from the overall time required to achieve the design’s objectives. To determine this, an optimization problem is formulated which minimizes time spent in the design process. In this optimization problem the design variables are the binary choice whether or not to perform an error check. The approach is demonstrated in two case studies, one a simple theoretical design problem and the other the design of an I-beam. The results of these case studies demonstrate the approach’s effectiveness, and present several avenues for future work.

scholarly journals Integrated uncertainty techniques in aircraft derivative design optimization.

2021 ◽  
Author(s):  
Hyeong-Uk Park
Keyword(s):  
Sensitivity Analysis ◽  
Design Optimization ◽  
Design Process ◽  
Aircraft Design ◽  
Collaborative Optimization ◽  
Aircraft Manufacturing ◽  
Analysis Tools ◽  
Design Variables ◽  
The Cost ◽  
Aircraft Conceptual Design

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet the new market demands while keeping the development time and the cost to a minimum. Many researchers have studied the derivative design process, but these research considered the baseline and the derivatives together, while using the whole set of design variables. Therefore, an efficient process that can reduce the cost and the time for the aircraft derivative design is needed. In this dissertation, Aircraft Derivative Design Optimization process (ADDOPT) was developed which obtains the global changes from the local changes in the aircraft design to develop the aircraft derivatives efficiently. The sensitivity analysis was implemented to ignore design variables that have low impact on the objective function. This avoids wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, the classification of uncertainty from its characteristics and sources of uncertainty involved in the aircraft design process were suggested to consider with design optimization. Uncertainty from the fidelity of analysis tools was applied in design optimization to increase the probability of optimization results. To handle uncertainty in low fidelity analysis tools on aircraft conceptual design optimization, Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were performed. In this research, Extended Fourier Amplitude Sensitivity Test (eFAST) method was implemented in ADDOPT for Global Sensitivity Analysis (GSA) method and Collaborative Optimization (CO) based framework with RBDO and PBDO were also used. These methods were evaluated using numerical examples. ADDOPT was carried through on the civil jet aircraft derivative design. The objective of the optimization problem was to increase cruise range while satisfying the requirement such as the number of passengers. The proposed process reduced computation effort by reducing the number of design variables and achieved the target probability of failure when considering uncertainty from low fidelity analysis tools.

Quantification of Symmetry, Parallelism, and Continuity as Continuous Design Variables for Three-Dimensional Product Representations

2016 ◽  
Author(s):  
Ambrosio Valencia-Romero ◽  
José E. Lugo
Keyword(s):  
Design Process ◽  
Online Survey ◽  
Three Dimensional ◽  
Product Representation ◽  
Gestalt Principles ◽  
Logit Regression ◽  
Irregular Shapes ◽  
Design Variables ◽  
Future Work ◽  
3D Representations

This work introduces a methodology to quantify the form of a three-dimensional (3D) product representation using the Gestalt principles of symmetry, parallelism, and continuity, and how they can be used as descriptive parameters in product design. First, consistent quantifications of these three Gestalt principles for parametrized 3D representations in a zero-one scale are presented. Then, a generalized methodology applicable to any product form is discussed. It starts with the identification of important aesthetic forms of the product shape and the Gestalt principles that best related to those forms, and ends with the quantification of these Gestalt principles of a 3D product representation. The expressions to quantify the Gestalt principles in question are validated through an online survey in which subjects indicated how much they recognize symmetry, parallelism, or continuity from irregular shapes. Finally, random-effects ordered logit regression is used to determine if the expressions effectively describe the level of recognition of each Gestalt principle. Results show that the proposed quantifications for symmetry, parallelism, and continuity are congruent with subjects perception of these Gestalt principles, and the implications for designers and future work are discussed. Further implications in the design process of these quantifications include the optimization of the product shape for aesthetic, semantic, and functional goals.

scholarly journals Gradient Span Analysis Method: Application to the Multipoint Aerodynamic Shape Optimization of a Turbine Cascade

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Hadrien Montanelli ◽  
Marc Montagnac ◽  
François Gallard
Keyword(s):  
Cost Function ◽  
Optimization Problem ◽  
Stokes Equations ◽  
Single Point ◽  
Operating Conditions ◽  
Design Variables ◽  
Wide Range ◽  
The Cost ◽  
Multipoint Optimization ◽  
Utopia Point

This paper presents the application of the gradient span analysis (GSA) method to the multipoint optimization of the two-dimensional LS89 turbine distributor. The cost function (total pressure loss) and the constraint (mass flow rate) are computed from the resolution of the Reynolds-averaged Navier–Stokes equations. The penalty method is used to replace the constrained optimization problem with an unconstrained problem. The optimization process is steered by a gradient-based quasi-Newton algorithm. The gradient of the cost function with respect to design variables is obtained with the discrete adjoint method, which ensures an efficient computation time independent of the number of design variables. The GSA method gives a minimal set of operating conditions to insert into the weighted sum model to solve the multipoint optimization problem. The weights associated to these conditions are computed with the utopia point method. The single-point optimization at the nominal condition and the multipoint optimization over a wide range of conditions of the LS89 blade are compared. The comparison shows the strong advantages of the multipoint optimization with the GSA method and utopia-point weighting over the traditional single-point optimization.

scholarly journals Integrated uncertainty techniques in aircraft derivative design optimization.

2021 ◽  
Author(s):  
Hyeong-Uk Park
Keyword(s):  
Sensitivity Analysis ◽  
Design Optimization ◽  
Design Process ◽  
Aircraft Design ◽  
Collaborative Optimization ◽  
Aircraft Manufacturing ◽  
Analysis Tools ◽  
Design Variables ◽  
The Cost ◽  
Aircraft Conceptual Design

Aircraft manufacturing companies have to consider multiple derivatives to satisfy various market requirements. They modify or extend an existing aircraft to meet the new market demands while keeping the development time and the cost to a minimum. Many researchers have studied the derivative design process, but these research considered the baseline and the derivatives together, while using the whole set of design variables. Therefore, an efficient process that can reduce the cost and the time for the aircraft derivative design is needed. In this dissertation, Aircraft Derivative Design Optimization process (ADDOPT) was developed which obtains the global changes from the local changes in the aircraft design to develop the aircraft derivatives efficiently. The sensitivity analysis was implemented to ignore design variables that have low impact on the objective function. This avoids wasting computational effort and time on low priority variables for design requirements and objectives. Additionally, the classification of uncertainty from its characteristics and sources of uncertainty involved in the aircraft design process were suggested to consider with design optimization. Uncertainty from the fidelity of analysis tools was applied in design optimization to increase the probability of optimization results. To handle uncertainty in low fidelity analysis tools on aircraft conceptual design optimization, Reliability Based Design Optimization (RBDO) and Possibility Based Design Optimization (PBDO) methods were performed. In this research, Extended Fourier Amplitude Sensitivity Test (eFAST) method was implemented in ADDOPT for Global Sensitivity Analysis (GSA) method and Collaborative Optimization (CO) based framework with RBDO and PBDO were also used. These methods were evaluated using numerical examples. ADDOPT was carried through on the civil jet aircraft derivative design. The objective of the optimization problem was to increase cruise range while satisfying the requirement such as the number of passengers. The proposed process reduced computation effort by reducing the number of design variables and achieved the target probability of failure when considering uncertainty from low fidelity analysis tools.

Topology Optimization of 3D Trusses With Cost of Supports

1993 ◽  
Author(s):  
Pauli Pedersen
Keyword(s):  
Topology Optimization ◽  
Local Stability ◽  
Optimization Problem ◽  
Basic Assumption ◽  
Load Condition ◽  
Compressive Stresses ◽  
Allowable Stresses ◽  
Design Variables ◽  
The Cost ◽  
Stated Problem

Abstract The basic assumption for the present paper is the single load condition. In other aspects the stated problem is rather general and the important issue of local stability is taken into account. Even for this problem we can always find a statically determined topology that will minimize the cost of the structure. The constraints of the optimization problem are allowable stresses, with the allowable compressive stresses being design-dependent. Supports are treated as design variables, and cost of a possible support can be given within the same generality as cost of truss members. The formulation is given in terms of bar forces and a modified Simplex technique is developed for the numerical solution.

Open Failure Diagnosis Candidate Selection Based on Passive Voltage Contrast Potential and Processing Cost

2013 ◽  
Author(s):  
Yan Pan ◽  
Oh Chong Khiam ◽  
Nyi Ohnmar ◽  
Chuan Zhang ◽  
Sekar Kannan ◽  
...  
Keyword(s):  
Case Studies ◽  
Cost Model ◽  
Turnaround Time ◽  
Candidate Selection ◽  
Failure Diagnosis ◽  
Extra Effort ◽  
Processing Cost ◽  
Voltage Contrast ◽  
The Cost ◽  
Future Work

Abstract With a focus on open failure candidates, an extra effort in defining the ease of physical failure analysis (PFA) processing is taken in this paper by closely modeling the PFA processing flow and detailed estimation of the processing cost involved in every step is made. The paper begins with a discussion on the general PFA procedure to process open failure candidates in logic circuits. This is followed by a section that reviews common practice in PFA candidate selection, before proposing the comprehensive selection flow that aims to filter out the easiest candidate in terms of processing cost. This methodology is then evaluated by several case studies and is followed by a discussion on the potential future work. Case studies show that the cost model closely matches with real-world PFA turnaround time and the authors are working toward automating the full flow in software to further improve the efficiency.

Are We There Yet? Investigating the Role of Design Process Architecture in Convergence Time

2009 ◽  
Author(s):  
Erich Devendorf ◽  
Kemper Lewis
Keyword(s):  
Design Process ◽  
Parallel Architecture ◽  
Convergence Time ◽  
Distributed Design ◽  
Theoretic Approach ◽  
Equilibrium Solutions ◽  
Design Variables ◽  
Decentralized Design ◽  
Time Required ◽  
Process Architecture

In distributed design individual designers have local control over design variables and seek to minimize their own individual objectives. The amount of time required to reach equilibrium solutions in decentralized design can vary based on the design process architecture chosen. There are two primary design process architectures, sequential and parallel, and a number of possible combinations of these architectures. In this paper a game theoretic approach is developed to determine the time required for a parallel and sequential architecture to converge to a solution for a two designer case. The equations derived solve for the time required to converge to a solution in closed form without any objective function evaluations. This result is validated by analyzing a distributed design case study. In this study the equations accurately predict the convergence time for a sequential and parallel architecture. A second validation is performed by analyzing a large number of randomly generated two designer systems. The approach in this case successfully predicts convergence within 3 iterations for nearly 98% of the systems analyzed. The remaining 2% highlight one of the approach’s weaknesses; it is susceptible to numerically ill conditioned problems. Understanding the rate at which distributed design problems converge is of key importance when determining design architectures. This work begins the investigation with a two designer case and lays the groundwork to expand to larger design systems with multiple design variables.

Use of cold tolerant eucalyptus species as a partial replacement for southern mixed hardwoods

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 29-35 ◽  
Author(s):  
PETER W. HART ◽  
DALE E. NUTTER
Keyword(s):  
Potential Method ◽  
The United States ◽  
Partial Replacement ◽  
Growth Time ◽  
Eucalyptus Species ◽  
Cold Tolerant ◽  
Hardwood Pulp ◽  
Time Required ◽  
The Cost ◽  
Operational Data

During the last several years, the increasing cost and decreasing availability of mixed southern hardwoods have resulted in financial and production difficulties for southern U.S. mills that use a significant percentage of hardwood kraft pulp. Traditionally, in the United States, hardwoods are not plantation grown because of the growth time required to produce a quality tree suitable for pulping. One potential method of mitigating the cost and supply issues associated with the use of native hardwoods is to grow eucalyptus in plantations for the sole purpose of producing hardwood pulp. However, most of the eucalyptus species used in pulping elsewhere in the world are not capable of surviving in the southern U.S. climate. This study examines the potential of seven different cold-tolerant eucalyptus species to be used as replacements for, or supplements to, mixed southern hardwoods. The laboratory pulping and bleaching aspects of these seven species are discussed, along with pertinent mill operational data. Selected mill trial data also are reviewed.

Shape Optimization of Hydraulic Structures: an Example of an Optimum Design of a Fish Passage

10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shape Optimization ◽  
Objective Function ◽  
Optimum Design ◽  
Optimization Problem ◽  
A Priori ◽  
Coupled System ◽  
Fish Passage ◽  
Hydraulic Structures ◽  
Design Variables

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.

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