A New Approach to Shape Optimization for Closed Path Synthesis of Planar Mechanisms

2005 ◽  
Vol 129 (9) ◽  
pp. 941-948 ◽  
Author(s):  
Ahmad Smaili ◽  
Nadim Diab
Keyword(s):  
Shape Optimization ◽  
Fourier Descriptors ◽  
Angular Deviation ◽  
Mathematical Approach ◽  
Closed Path ◽  
Planar Mechanisms ◽  
Simple Method ◽  
New Approach ◽  
Starting Point ◽  
Path Synthesis

A method for the synthesis of four-bar mechanisms to generate closed paths through shape optimization is herein introduced. The objective function is not based on Fourier descriptors, but rather on the cyclic angular deviation (CAD) vector associated with a set of desired points on the curve. A simple method is introduced to account for the starting point shift between the desired CAD and the generated one. Following shape optimization, a simple mathematical approach is devised to properly scale, rotate, and translate the mechanism to the desired configuration. Two case studies are presented to demonstrate the effectiveness and robustness of the proposed method.

A New Appraoch to Shape Optimization for Closed Path Synthesis of Planar Mechanisms

2005 ◽  
Author(s):  
Ahmad Smaili ◽  
Nadim Diab
Keyword(s):  
Shape Optimization ◽  
Fourier Descriptors ◽  
Angular Deviation ◽  
Mathematical Approach ◽  
Closed Path ◽  
Planar Mechanisms ◽  
Simple Method ◽  
Starting Point ◽  
Path Synthesis

A method for the synthesis of four-bar mechanisms to generate closed paths through shape optimization is herein introduced. The objective function is not based on Fourier descriptors, rather on the cyclic angular deviation (CAD) vector associated with a set of desired points on the curve. A simple method is introduced to account for the starting point shift between the desired CAD and the generated one. Following shape optimization, a simple mathematical approach is devised to properly scale, rotate, and translate the mechanism to the desired configuration. A case study is presented to demonstrate the effectiveness and robustness of the proposed method.

A New Approach for Exact/Approximate Point Synthesis of Planar Mechanisms

2005 ◽  
Author(s):  
Ahmad Smaili ◽  
Nadim Diab
Keyword(s):  
Synthesis Method ◽  
Dimensional Synthesis ◽  
Gradient Search ◽  
Planar Mechanisms ◽  
Simple Method ◽  
New Approach ◽  
Optimum Synthesis ◽  
Approximate Synthesis ◽  
Optimum Solution ◽  
Synthesis Approach

The aim of this article is to provide a simple method to solve the mixed exact-approximate dimensional synthesis problem of planar mechanism. The method results in a mechanism that can traverse a closed path with the choice of any number of exact points while the rest are approximate points. The algorithm is based on optimum synthesis rather than on precision position methods. Ant-gradient search is applied on an objective function based on log10 of the error between the desired positions and those generated by the optimum solution. The log10 function discriminates on the side of generating miniscule errors (on the order of 10−14) at the exact points while allowing for higher errors at the approximate positions. The algorithm is tested by way of five examples. One of these examples was used to test exact/approximate synthesis method based on precision point synthesis approach.

New approach to constrained shape optimization using genetic algorithms

AIAA Journal ◽  
1998 ◽  
Vol 36 ◽  
pp. 51-61 ◽  
Author(s):  
M. C. Sharatchandra ◽  
Mihir Sen ◽  
Mohamed Gad-el-Hak
Keyword(s):  
Genetic Algorithms ◽  
Shape Optimization ◽  
New Approach

scholarly journals Graph based discrete optimization in structural dynamics

2014 ◽  
Vol 62 (1) ◽  
pp. 91-102
Author(s):  
B. Blachowski ◽  
W. Gutkowski
Keyword(s):  
Structural Optimization ◽  
Minimum Weight ◽  
Continuous Optimization ◽  
Graph Representation ◽  
Wind Loading ◽  
Transmission Tower ◽  
Simple Method ◽  
Deterministic Dynamic ◽  
Starting Point ◽  
Discrete Values

Abstract In this study, a relatively simple method of discrete structural optimization with dynamic loads is presented. It is based on a tree graph, representing discrete values of the structural weight. In practical design, the number of such values may be very large. This is because they are equal to the combination numbers, arising from numbers of structural members and prefabricated elements. The starting point of the method is the weight obtained from continuous optimization, which is assumed to be the lower bound of all possible discrete weights. Applying the graph, it is possible to find a set of weights close to the continuous solution. The smallest of these values, fulfilling constraints, is assumed to be the discrete minimum weight solution. Constraints can be imposed on stresses, displacements and accelerations. The short outline of the method is presented in Sec. 2. The idea of discrete structural optimization by means of graphs. The knowledge needed to apply the method is limited to the FEM and graph representation. The paper is illustrated with two examples. The first one deals with a transmission tower subjected to stochastic wind loading. The second one with a composite floor subjected to deterministic dynamic forces, coming from the synchronized crowd activities, like dance or aerobic.

scholarly journals Reconciling Loss Aversion and Gain Seeking in Judged Emotions

2021 ◽  
pp. 096372142199204
Author(s):  
Barbara A. Mellers ◽  
Siyuan Yin ◽  
Jonathan Z. Berman
Keyword(s):  
Loss Aversion ◽  
Reference Point ◽  
Emotional Reactions ◽  
Status Quo ◽  
New Approach ◽  
Negative Change ◽  
Starting Point ◽  
The Status ◽  
Positive Feelings ◽  
Negative Feelings

Is the pain of a loss greater in magnitude than the pleasure of a comparable gain? Studies that compare positive feelings about a gain with negative feelings about a comparable loss have found mixed answers to this question. The pain of a loss can be greater than, less than, or equal to the pleasure of a comparable gain. We offer a new approach to test hedonic loss aversion. This method uses emotional reactions to the reference point, a positive change, and a negative change. When we manipulated the reference point (i.e., pleasurable and painful), two distinct patterns emerged. Pain surpassed pleasure (loss aversion) when the reference point was positive, and pleasure exceeded pain (gain seeking) when the reference point was negative. A reference-dependent version of prospect theory accounts for the results. If the carriers of utility are changes from a reference point—not necessarily the status quo—both loss aversion and gain seeking are predicted. Loss aversion and gain seeking can be reconciled if you take the starting point into account.

Beyond the heuristic approach to Kolmogorov-Smirnov theorems

1982 ◽  
Vol 19 (A) ◽  
pp. 359-365 ◽  
Author(s):  
David Pollard
Keyword(s):  
Weak Convergence ◽  
Goodness Of Fit ◽  
Empirical Distribution ◽  
Distribution Functions ◽  
Heuristic Approach ◽  
Convergence Theory ◽  
Simple Method ◽  
Starting Point ◽  
Kolmogorov Smirnov ◽  
The Subject

The theory of weak convergence has developed into an extensive and useful, but technical, subject. One of its most important applications is in the study of empirical distribution functions: the explication of the asymptotic behavior of the Kolmogorov goodness-of-fit statistic is one of its greatest successes. In this article a simple method for understanding this aspect of the subject is sketched. The starting point is Doob's heuristic approach to the Kolmogorov-Smirnov theorems, and the rigorous justification of that approach offered by Donsker. The ideas can be carried over to other applications of weak convergence theory.

scholarly journals Calculating Value Added of Prostitution with Multiple Data: A New Approach for Belgium

2017 ◽  
Vol 47 (1) ◽  
pp. 58-86 ◽  
Author(s):  
Stef Adriaenssens ◽  
Jef Hendrickx
Keyword(s):  
Sex Workers ◽  
Relative Size ◽  
Value Added ◽  
Added Value ◽  
Standard Errors ◽  
New Approach ◽  
Economic Output ◽  
Multiple Data ◽  
Innovative Methodology ◽  
Starting Point

Economic output implies that underground sectors such as prostitution are taken into account. This article presents an innovative methodology to measure turnover and added value in prostitution based on a combination of observational and Internet data. The method is applied to Belgium. Turnover is broken down in transactions and price per segment. The starting point is an observation-based measure of turnover in one locational and visible segment of the market: window prostitution. Fundamental differences between segments make linear generalizations from one segment invalid. Therefore, we estimate the relative size of transactions in other segments (such as brothels or escort) with Internet data. In combination with measures of average price per transaction, a consolidated estimate of turnover in prostitution in Belgium is measured. Estimates of nonresident production are based on data on sex workers’ country of origin. Several bootstrap replications allow for robustness checks of the delta-based standard errors.

scholarly journals Decision making in reverse logistics using system dynamics

2004 ◽  
Vol 14 (2) ◽  
pp. 259-272 ◽  
Author(s):  
P. Georgiadis ◽  
D. Vlachos
Keyword(s):  
Decision Making ◽  
System Dynamics ◽  
Reverse Logistics ◽  
Closed Loop ◽  
System Modeling ◽  
New Approach ◽  
Helpful Tool ◽  
Starting Point ◽  
Decision Making Tool

Reverse logistics is a modern field of consideration, research and study, providing helpful information on the operation of the closed-loop supply chain. Although the starting point of this field is traced back to the early 90?s, no standard method has been suggested, neither prevailed. The purpose of this paper is to introduce a new approach on the study of reverse logistics. It is actually a review on how System Dynamics (SD) can be a helpful tool when it is used in the reverse logistics field. The paper explains the basic theory of the system modeling and next it utilizes the reverse logistics model. Finally, an illustrative example shows how SD modeling can be used to produce a powerful long-term decision-making tool.

scholarly journals Human Machines Petrified: Play's Mineral Mechanics and Les statues meurent aussi

2019 ◽  
Vol 28 (2) ◽  
pp. 179-196
Author(s):  
Olga Beloborodova ◽  
Pim Verhulst
Keyword(s):  
Human Subjects ◽  
The Body ◽  
French Translation ◽  
New Approach ◽  
Life And Death ◽  
Starting Point ◽  
Critical Attention ◽  
Mechanical Devices ◽  
Sentient Beings

Play is usually regarded as the starting point of Beckett's late theatre, introducing a radically new approach to the body and language that set a benchmark for subsequent plays such as Not I, That Time and Footfalls. Building on Krapp's Last Tape and Happy Days, Play dehumanizes its characters by means of the audiovisual technologies that Beckett was experimenting with at the time. In this process, his human subjects are increasingly reduced to mechanical devices or mouthpieces for the conveyance of speech, instead of represented as recognizable and sentient beings of flesh and blood. The nonhuman aspect of Play is enhanced by its foregrounding of Beckett's long-standing fascination with the mineral, with the characters' faces being ‘so lost to age and aspect as to seem almost part of the urns’. Whereas, separately, the influence of radio, television and cinema on Play has received some critical attention, and James Knowlson, Claire Lozier, Mark Nixon, Jean-Michel Rabaté and Conor Carville, among others, have noted Beckett's fascination with the sculptural arts and the inorganic, this paper aims to merge those two strands by discussing the docufilm Les statues meurent aussi (1953) as a potential but overlooked source of inspiration. By combining the technological and the sculptural in Play, Beckett stages a ‘mineral mechanics’ verging closely on the nonhuman without being fully dehumanized, as characters continue to laugh and hiccup, barely retaining a trace of their humanity. This oscillation from the human to the nonhuman and vice versa is clearly traceable in the genesis of the text, as well as its French translation (Comédie). The result, Play's iconic stage image, is marked by the familiar Beckettian trope of in-betweenness: between life and death, between the organic and the mineral, between the natural and the technological.

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