An Optimal Parametrization Scheme for Path Generation Using Fourier Descriptors for Four-Bar Mechanism Synthesis

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Shashank Sharma ◽  
Anurag Purwar ◽  
Q. Jeffrey Ge
Keyword(s):  
Time Parameter ◽  
Fourier Descriptors ◽  
Fourier Descriptor ◽  
Mechanism Synthesis ◽  
Parametrization Scheme ◽  
Time Parameters ◽  
Path Synthesis ◽  
Parameter Values ◽  
The Given ◽  
Selection Of

Fourier descriptor (FD)-based path synthesis algorithms for generation of planar four-bar mechanisms require assigning time parameter values to the given points along the path. An improper selection of time parameters leads to poor fitting of the given path and suboptimal four-bar mechanisms while also ignoring a host of mechanisms that could be potentially generated otherwise. A common approach taken is to use uniform time parameter values, which does not take into account the unique harmonic properties of the coupler path. In this paper, we are presenting a nonuniform parametrization scheme in conjunction with an objective function that provides a better fit, leverages the harmonics of the four-bar coupler, and allows imposing additional user-specified constraints.

Optimal Non-Uniform Parametrization for Fourier Descriptor Based Path Synthesis of Four Bar Mechanisms

2018 ◽  
Author(s):  
Shashank Sharma ◽  
Anurag Purwar ◽  
Q. Jeffrey Ge
Keyword(s):  
Input Data ◽  
Design Space ◽  
Fourier Descriptors ◽  
Fourier Descriptor ◽  
Loop Closure ◽  
The Core ◽  
Closure Equation ◽  
Harmonic Decomposition ◽  
Path Synthesis

Fourier descriptor based path synthesis algorithms rely on harmonic decomposition of four-bar loop closure equation to split the design space into smaller subsets. The core of the methodology depends on calculation and fitting of Fourier descriptors. However, a uniform time parametrization is assumed in existing literature. This paper aims to explore the use of non-uniform time parametrization of input data and calculation of an optimal parametrization. Additionally, design-centric constraints have been proposed to give user enhanced control over coupler speed. As a result, this work improves the existing algorithm tremendously.

scholarly journals PEMILIHAN NILAI PARAMETER C PADA INTERPOLAN GAUSSIAN

2019 ◽  
Vol 20 (1) ◽  
pp. 1-8
Author(s):  
Elin Herlinawati
Keyword(s):  
Optimum Parameter ◽  
Gaussian Function ◽  
Data Set ◽  
Error Vector ◽  
Data Points ◽  
Parameter Values ◽  
The Given ◽  
Selection Of

Interpolation is to find a function  which passes through a number of given data points. The interpolant that we used is a Gaussian function which has a parameter value of c. Selection of this parameter affects the results of interpolation. This study discusses a method that we used in selecting the optimum parameter of c. This method is inspired by a RMS (Root Means Square)error. Suppose  with is the set of data points. Define the error vector with    gk - yk - Fk(xk), k  E{1, 2, ..., n} ,   where  is the function value in  and  is the interpolant which is obtained by deleting a point  from the given data set. Furthermore, the optimum parameter value of c is selected by minimizing the error vector g. The result of selecting parameter values ​​depends on the amount of data and the distribution of known data.   Interpolasi adalah pencarian fungsi  melalui sejumlah titik data yang diberikan. Interpolan yang digunakan pada artikel ini adalah fungsi Gaussian yang memiliki nilai parameter . Pemilihan nilai parameter  mempengaruhi hasil interpolasi. Artikel ini membahas metode yang digunakan dalam pemilihan parameter  yang optimum. Metode ini terinspirasi dari galat RMS (Root Means Square). Misalkan dengan  adalah himpunan titik data yang diberikan. Didefinisikan vektor galat  dengan   gk - yk - Fk(xk), k  E{1, 2, ..., n} ,   adalah nilai fungsi di  dan  adalah interpolan yang diperoleh dengan menghapus satu titik  dari himpunan data yang diberikan. Selanjutnya, nilai parameter yang optimum dipilih dengan cara meminimumkan vektor galat . Hasil dari pemilihan nilai parameter bergantung pada banyaknya data dan sebaran data yang diketahui.

Application of the turbidity ratio method in the spherical particle size determination in the range m ∈ and α ∈

1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann
Keyword(s):  
Refractive Index ◽  
Spherical Particle ◽  
Ratio Method ◽  
Refractive Indices ◽  
Relative Refractive Index ◽  
Particle Size Determination ◽  
The Individual ◽  
The Given ◽  
Turbidity Ratio ◽  
Selection Of

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.

A network thermodynamic model of salt and water flow across the kidney proximal tubule

1978 ◽  
Vol 235 (6) ◽  
pp. F638-F648 ◽  
Author(s):  
S. R. Thomas ◽  
D. C. Mikulecky
Keyword(s):  
Proximal Tubule ◽  
Water Flow ◽  
Thermodynamic Model ◽  
Circuit Simulation ◽  
Basolateral Membrane ◽  
Kidney Proximal Tubule ◽  
Network Analyses ◽  
Pump Rate ◽  
Parameter Values ◽  
The Given

This network thermodynamic model of kidney proximal tubule epithelium treats coupled salt and water flow across each component membrane of the epithelium. We investigate the effects of various relative internal parameter values on the concentration of transepithelial flow, the concentrations in the cell and interspace, and the distribution of flows between cellular and paracellular routes. Best fit is obtaine if the apical and basolateral membrane reflection coefficients (or) are equal. The measured transepithelial filtration coefficient, Lp, is a function not only of the component Lps but also of the internal concentrations, or's, and permeabilities. For the given system topology (i.e., connectedness), parameters of component membranes must be within a narrow range to be consistent with experimental results. The dependence of the concentration of transported fluid on the balance between the solute pump rate and the transepithelial volume flow driving force is shown. This has implications for the effects of peritubular or lumen oncotic pressure on salt and water flow. With Appendix B of this paper and a user's guide for a circuit-simulation package (e.g., SPICE or PCAP) the reader can perform similar network analyses of transport models himself.

A More Effective Formulation of the Path Generation Mechanism Synthesis Problem

1994 ◽  
Author(s):  
Irfan Ullah ◽  
Sridhar Kota
Keyword(s):  
Objective Function ◽  
Error Function ◽  
Mathematical Optimization ◽  
Optimization Methods ◽  
Complex Nature ◽  
Mechanism Synthesis ◽  
Structural Error ◽  
Crank Angle ◽  
The Common ◽  
Selection Of

Abstract Use of mathematical optimization methods for synthesis of path-generating mechanisms has had only limited success due to the very complex nature of the commonly used Structural Error objective function. The complexity arises, in part, because the objective function represents not only the error in the shape of the coupler curve, but also the error in location, orientation and size of the curve. Furthermore, the common introduction of timing (or crank angle), done generally to facilitate selection of corresponding points on the curve for calculating structural error, has little practical value and unnecessarily limits possible solutions. This paper proposes a new objective function, based on Fourier Descriptors, which allows search for coupler curve of the desired shape without reference to location, orientation, or size. The proposed objective function compares overall shape properties of curves rather than making point-by-point comparison and therefore does not requires prescription of timing. Experimental evidence is provided to show that it is much easier to search the space of the proposed objective function compared to the structural error function.

scholarly journals Categorization of the main descriptors of different ampicillin crystal habits

2010 ◽  
Vol 46 (4) ◽  
pp. 679-685 ◽  
Author(s):  
Oscar Flórez-Acosta ◽  
Gloria Tobón-Zapata ◽  
Jaime Valencia-Velasquez
Keyword(s):  
Principal Component Analysis ◽  
Raw Materials ◽  
Principal Component ◽  
Crystal Habit ◽  
Morphological Properties ◽  
Effective Diameter ◽  
Fourier Descriptors ◽  
Morphological Descriptors ◽  
Digital Methods ◽  
Selection Of

With the purpose of enabling the analysis by digital methods of particles of multisource pharmaceutical raw materials, this study analyzed different crystal habits of ampicillin particles, by grouping the external shapes obtained from 3 different solvents (acetonitrile, ethanol, and methanol), thereby reducing the number of descriptors necessary to adequately represent each shape. For this purpose, a selection of morphological descriptors was used including: circularity, roughness, roundness, compactness, aspect ratio, effective diameter, solidity, convexity, fractal dimension, and 10 Complex Fourier descriptors. These measures cover highly diverse morphological properties and define the crystal habit of a particle. Principal Component Analysis (PCA) and the Cluster Analysis (CA) were the grouping techniques used, which demonstrated the possibility of using between 2 and 4 descriptors instead of the 18 proposed initially.

scholarly journals THE STYLISTIC FUNCTIONING OF SCRIPTURAL ALLUSIONS IN AN EARLY MODERN ENGLISH PLAY “JOHAN BAPTYSTES PREACHYNGE” BY J. BALE

2020 ◽  
Vol 30 (6) ◽  
pp. 1001-1007
Author(s):  
A.A. Khavronich
Keyword(s):  
Early Modern ◽  
Early Modern English ◽  
Semantic Expansion ◽  
Early English ◽  
The Given ◽  
Selection Of

The given article analyzes the peculiarities of the stylistic functioning of allusions to the Holy Scripture within one religious play belonging to the modern early English period, namely “Johan Baptystes Preachynge” produced by a dramatist J. Bale. The analysis is performed from the standpoint of linguopoetics. We consider stylistic features via the correlation of form and meaning, dissection of the conceptual component, juxtaposition with medieval plays representing adaptations of the same scriptural plot. Within the framework of this analysis we identify and assess elements performing the function of impact incorporated into the scriptural allusions and estimate their role in the selection of other lexical units, construction of extended metaphors, syntactic shaping of particular fragments of the play. We draw a conclusion that via the extension of scriptural metaphorical complexes the author brings about a meaningful focus shift to ensure a protestant reinterpretation of the included biblical theses. A substantial share of stylistically marked elements undergoes semantic expansion and develops adherent connotations since they relate to the pivotal elements of the allusions.

scholarly journals Selection of the variant solution of forest road alignment conceptual design using multicriteria optimisation

2009 ◽  
pp. 165-176 ◽  
Author(s):  
Bogdan Stefanovic ◽  
Ivan Bjelanovic
Keyword(s):  
Conceptual Design ◽  
Multicriteria Optimization ◽  
Linear Distribution ◽  
Forest Road ◽  
Multicriteria Optimisation ◽  
Technical Production ◽  
The Given ◽  
Selection Of ◽  
Design Construction ◽  
Building Parameters

One of the three studied variant solutions of forest road conceptual design was selected based on the linear distribution of criteria, as the method of multicriteria optimization. The selection was performed with 25 parameters classified as economic, technical, production and social criteria. The parameters of technical criteria were grouped into design, construction and building parameters. Based on calculated nominal values of parameters by the given criteria, their ranking, comparison, point rating and scoring, the selected most favorable solution was variant 1.

scholarly journals Vulnerability analysis and method of selection of communication protocols for information transfer in Internet of Things systems

2021 ◽  
pp. 133-149
Author(s):  
Maryna Kolisnyk
Keyword(s):  
Internet Of Things ◽  
Initial Data ◽  
Information Transfer ◽  
System Analysis ◽  
Communication Protocols ◽  
Critical Systems ◽  
Smart Objects ◽  
Corporate System ◽  
The Given ◽  
Selection Of

The subject of study in the paper is the analysis of technologies, architectures, vulnerabilities and cyberattacks, communication patterns of smart objects, messaging models, and Internet of Things (IoT) / Web of Things (WoT) protocols for solving applied problems of critical and non-critical systems. The goal is to develop a method for selecting messaging models and application-level protocols in non-critical and critical multi-level IoT/WoT systems, provided that the type of access to intelligent objects is initially determined by the initial data, as well as analysis of vulnerabilities and attacks using these protocols. Objectives: to formalize the procedure for choosing communication protocols for IoT/WoT systems; analyze possible vulnerabilities of communication protocols; develop a method for selecting communication protocols for given initial data, depending on the selected type of communication template for smart objects; check practically the proposed method. The methods of research are methods of system analysis. The following results were obtained. The analysis of the features of communication protocols is conducted by comparing the main interrelated characteristics of IoT/WoT, the results of which are presented in the form of a table. A method has been developed for selecting communication protocols, depending on the selected type of communication template. The analysis of possible vulnerabilities of communication protocols and possible attacks using these protocols is conducted. The author has tested the method using the example of a corporate system (Smart House) based on the WoT concept. Findings. The scientific novelty of the results obtained is as follows: the analysis conducted in the paper shows that currently there is no unified approach to the choice of a messaging model and application-level protocols for building IoT/WoT, depending on the selected type of communication template for smart objects. The method for selecting communication protocols for the given conditions (for each IoT system its interaction pattern will correspond, depending on which components interact with each other), improved by the authors of the paper, makes it possible to simplify the task of using separate protocols for given IoT systems, considering vulnerabilities of protocols.

scholarly journals Selection of Pairings Reaching Evenly Across the Data (SPREAD): A simple algorithm to design maximally informative fully crossed mating experiments

2014 ◽  
Author(s):  
Kolea Zimmerman ◽  
Daniel Levitis ◽  
Ethan Addicott ◽  
Anne Pringle
Keyword(s):  
Nearest Neighbor ◽  
Simple Algorithm ◽  
Two Dimensional ◽  
Neighbor Distance ◽  
Crossing Experiments ◽  
The Mean ◽  
Parameter Values ◽  
Selection Of ◽  
Novel Algorithm ◽  
Trait Space

We present a novel algorithm for the design of crossing experiments. The algorithm identifies a set of individuals (a ?crossing-set?) from a larger pool of potential crossing-sets by maximizing the diversity of traits of interest, for example, maximizing the range of genetic and geographic distances between individuals included in the crossing-set. To calculate diversity, we use the mean nearest neighbor distance of crosses plotted in trait space. We implement our algorithm on a real dataset ofNeurospora crassastrains, using the genetic and geographic distances between potential crosses as a two-dimensional trait space. In simulated mating experiments, crossing-sets selected by our algorithm provide better estimates of underlying parameter values than randomly chosen crossing-sets.

Sign in / Sign up

Export Citation Format

Share Document