Minimum Mass Design of Boiler Drums by Nonlinear Programming

1985 ◽  
Vol 107 (1) ◽  
pp. 83-87 ◽  
Author(s):  
J. Kowalski
Keyword(s):  
Mathematical Modeling ◽  
Nonlinear Programming ◽  
Objective Function ◽  
Optimum Design ◽  
Optimization Problem ◽  
Systems Approach ◽  
Dimensional Space ◽  
Minimum Mass ◽  
Design Features ◽  
Numerical Example

Based on the systems approach to mathematical modeling, the paper shows the method for selecting the optimum design features of boiler drums with a given structure for minimum mass. The optimization problem is reduced to finding the minimum of the objective function in a 10-dimensional space bounded by 11 constraints. The numerical example has been presented.

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.

scholarly journals Cost Optimal Project Scheduling

Organizacija ◽  
2008 ◽  
Vol 41 (4) ◽  
pp. 153-158
Author(s):  
Uroš Klanšek ◽  
Mirko Pšunder
Keyword(s):  
Nonlinear Programming ◽  
Objective Function ◽  
Project Scheduling ◽  
Programming Approach ◽  
Project Duration ◽  
Numerical Example ◽  
Activity Duration ◽  
The Cost ◽  
Total Project Cost ◽  
Total Project

Cost Optimal Project SchedulingThis paper presents the cost optimal project scheduling. The optimization was performed by the nonlinear programming approach, NLP. The nonlinear total project cost objective function is subjected to the rigorous system of the activity precedence relationship constraints, the activity duration constraints and the project duration constraints. The set of activity precedence relationship constraints was defined to comprise Finish-to-Start, Start-to-Start, Start-to-Finish and Finish-to-Finish precedence relationships between activities. The activity duration constraints determine relationships between minimum, maximum and possible duration of the project activities. The project duration constraints define the maximum feasible project duration. A numerical example is presented at the end of the paper in order to present the applicability of the proposed approach.

scholarly journals Optimization of asymmetric I-beams for minimum welding shrinkage

2021 ◽  
Author(s):  
Károly Jármai ◽  
Máté Petrik
Keyword(s):  
Aluminum Alloys ◽  
Objective Function ◽  
Yield Stress ◽  
Optimum Design ◽  
Heat Input ◽  
Local Buckling ◽  
Minimum Mass ◽  
Span Length ◽  
Steel Grades ◽  
Calculation System

AbstractA calculation system has been developed to determine the optimum dimensions of asymmetric I-beams for minimum shrinkage. The objective function is the minimum mass; the unknowns are the I-beam dimensions; the constraints are the stress, local buckling, and deflection. Different steel grades have been considered (235, 355, 460 (MPa) yield stress) and other aluminum alloys (90, 155, 230 (MPa) yield stress). The material, the span length, the loading, and the applied heat input have been changed. It is shown, that using optimum design; the welding shrinkage can be reduced with prebending and can save material cost as well.

scholarly journals Combination of anti-optimization and fuzzy-set-based analysis for structural optimization under uncertainty

1998 ◽  
Vol 4 (3) ◽  
pp. 187-200 ◽  
Author(s):  
J. Fang ◽  
S. M. Smith ◽  
I. Elishakoff
Keyword(s):  
Structural Optimization ◽  
Objective Function ◽  
Optimum Design ◽  
Fuzzy Set ◽  
Optimization Problem ◽  
Fuzzy Optimization ◽  
Optimization Methods ◽  
Optimization Under Uncertainty ◽  
Optimization Process ◽  
Membership Functions

An approach to the optimum design of structures, in which uncertainties with a fuzzy nature in the magnitude of the loads are considered, is proposed in this study. The optimization process under fuzzy loads is transformed into a fuzzy optimization problem based on the notion of Werners' maximizing set by defining membership functions of the objective function and constraints. In this paper, Werner's maximizing set is defined using the results obtained by first conducting an optimization through anti-optimization modeling of the uncertain loads. An example of a ten-bar truss is used to illustrate the present optimization process. The results are compared with those yielded by other optimization methods.

An Operation Strategy for Mathematical Modeling in Optimum Design of Machine Construction

1985 ◽  
Vol 107 (4) ◽  
pp. 463-476 ◽  
Author(s):  
J. Kowalski
Keyword(s):  
Mathematical Modeling ◽  
Quality Control ◽  
Optimum Design ◽  
Systems Approach ◽  
Optimization Theory ◽  
Machine Construction ◽  
Operation Strategy ◽  
Model Based ◽  
Product Models

The paper describes an operation strategy, based on the systems approach, to enable quality control for design of products. The ideas outlined make possible a two-level hierarchic modeling system controlled according to principles of classification of product models. Elements of the optimization theory for model-based design are given, including an application example for the optimum design of a self-loading trailer assembly.

AN FPTAS FOR COMPUTING THE SIMILARITY OF THREE-DIMENSIONAL POINT SETS

2007 ◽  
Vol 17 (02) ◽  
pp. 161-174 ◽  
Author(s):  
STEFAN KIRCHNER
Keyword(s):  
Combinatorial Optimization ◽  
Objective Function ◽  
Optimization Problem ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Rigid Motion ◽  
Similarity Score ◽  
Combinatorial Optimization Problem ◽  
Maximum Value ◽  
Three Dimensional Space

We present an FPTAS for a combinatorial optimization problem which is motivated by a problem in drug-design. The problem is as follows. One is given two finite subsets A,B of points in three-dimensional space which represent the centers of atoms of two molecules. The objective function is large if there are an appropriate rigid motion M, subsets S ⊂ A and T ⊂ B of the same size and a bijective function f from S to M(T) such that |S| is sufficiently large and the root mean squared distance between S and f(S) is small. The object is to find M and f such that the objective function is maximized. The corresponding maximum value defines the similarity score between two molecules.

scholarly journals An Improved Filter Method for Nonlinear Complementarity Problem

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Ke Su ◽  
Xiaoli Lu ◽  
Wei Liu
Keyword(s):  
Nonlinear Programming ◽  
Objective Function ◽  
Complementarity Problem ◽  
Nonlinear Complementarity Problem ◽  
Filter Method ◽  
Filter Technique ◽  
Numerical Example ◽  
Nonlinear Complementarity ◽  
Mild Conditions ◽  
Nonsmooth Function

The nonlinear complementarity problem can be reformulated as a nonlinear programming whose objective function may be nonsmooth. For this case, we use decomposition strategy to decompose the nonsmooth function into a smooth one and a nonsmooth one. Together with filter method, we present an improved filter algorithm with decomposition strategy for solving nonlinear complementarity problem, which has better numerical results compared to the method that without the filter technique. Under mild conditions, the global convergent property is shown. In the end, the numerical example is reported.

On the displacements of the contours of the optic-electronic space images. Mathematical modeling of displacement

2017 ◽  
Vol 992 (4) ◽  
pp. 32-38 ◽  
Author(s):  
E.G. Voronin
Keyword(s):  
Mathematical Modeling ◽  
Remote Sensing ◽  
Mathematical Model ◽  
Point Of View ◽  
Design Features ◽  
Space Images ◽  
Electronic Imaging ◽  
Measuring Accuracy ◽  
Physical Laws

The article opens a cycle of three consecutive publications dedicated to the phenomenon of the displacement of the same points in overlapping scans obtained adjacent CCD matrices with opto-electronic imagery. This phenomenon was noticed by other authors, but the proposed explanation for the origin of displacements and the resulting estimates are insufficient, and developed their solutions seem controversial from the point of view of recovery of the measuring accuracy of opticalelectronic space images, determined by the physical laws of their formation. In the first article the mathematical modeling of the expected displacements based on the design features of a scanning opto-electronic imaging equipment. It is shown that actual bias cannot be forecast, because they include additional terms, which may be gross, systematic and random values. The proposed algorithm for computing the most probable values of the additional displacement and ways to address some of the systematic components of these displacements in a mathematical model of optical-electronic remote sensing.

DUAL FORMULATION OF OPTIMAL PROBLEM FOR CONTINUOUS-TIME SYSTEMS

2005 ◽  
Vol 02 (03) ◽  
pp. 251-258
Author(s):  
HANLIN HE ◽  
QIAN WANG ◽  
XIAOXIN LIAO
Keyword(s):  
Objective Function ◽  
Continuous Time ◽  
Dimensional Space ◽  
Finite Dimensional Space ◽  
Error Response ◽  
Infinite Dimensional ◽  
Dual Formulation ◽  
Finite Dimensional ◽  
Continuous Time Systems ◽  
Time Systems

The dual formulation of the maximal-minimal problem for an objective function of the error response to a fixed input in the continuous-time systems is given by a result of Fenchel dual. This formulation probably changes the original problem in the infinite dimensional space into the maximal problem with some restrained conditions in the finite dimensional space, which can be researched by finite dimensional space theory. When the objective function is given by the norm of the error response, the maximum of the error response or minimum of the error response, the dual formulation for the problems of L1-optimal control, the minimum of maximal error response, and the minimal overshoot etc. can be obtained, which gives a method for studying these problems.

Improvement of the Static and Dynamic Characteristics of Magnetic Head Sliders by Optimum Design

1999 ◽  
Vol 122 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Hiromu Hashimoto ◽  
Yasuhisa Hattori
Keyword(s):  
Objective Function ◽  
Optimum Design ◽  
Amplitude Ratio ◽  
Optimization Technique ◽  
Hard Disk Drives ◽  
Maximum Amplitude ◽  
Disk Surface ◽  
Operating Conditions ◽  
Magnetic Head ◽  
Design Variables

The aim of this paper is to develop a general methodology for the optimum design of magnetic head sliders in improving the spacing characteristics between a slider and disk surface under static and dynamic operating conditions of hard disk drives and to present an application of the methodology to the IBM 3380-type slider design. To generate the optimal design variables, the objective function is defined as the weighted sum of the minimum spacing, the maximum difference in the spacing due to variation of the radial location of the head, and the maximum amplitude ratio of the slider motion. Slider rail width, taper length, taper angle, suspension position, and preload are selected as the design variables. Before the optimization of the head, the effects of these five design variables on the objective function are examined by a parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique, combining the direct search method and successive quadratic programming. From the obtained results, the effectiveness of optimum design on the spacing characteristics of magnetic heads is clarified. [S0742-4787(00)03701-2]

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