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Graphs with no induced five-vertex path or antipath  [PDF]
Maria Chudnovsky,Louis Esperet,Laetitia Lemoine,Peter Maceli,Frédéric Maffray,Irena Penev
Computer Science , 2014,
Abstract: We prove that a graph $G$ contains no induced $5$-vertex path and no induced complement of a $5$-vertex path if and only if $G$ is obtained from $5$-cycles and split graphs by repeatedly applying the following operations: substitution, split unification, and split unification in the complement, where split unification is a new class-preserving operation introduced here.
Thermodynamic Length, Time, Speed and Optimum Path to Minimize Entropy Production  [PDF]
L. Diosi,K. Kulacsy,B. Lukacs,A. Rácz
Physics , 1995, DOI: 10.1063/1.472897
Abstract: In addition to the Riemannian metricization of the thermodynamic state space, local relaxation times offer a natural time scale, too. Generalizing existing proposals, we relate {\it thermodynamic} time scale to the standard kinetic coefficients of irreversible thermodynamics. Criteria for minimum entropy production in slow, slightly irreversible processes are discussed. Euler-Lagrange equations are derived for optimum thermodynamic control for fixed clock-time period as well as for fixed {\it thermodynamic} time period. Only this latter requires constant thermodynamic speed as the optimum control proposed earlier. An easy-to-implement stepwise algorithm is constructed to realize control at constant thermodynamic speed. Since thermodynamic time is shown to correspond to the number of steps, thus the sophisticated task of determining thermodynamic time in real control problems can be substituted by measuring ordinary intensive variables. Most remarkably, optimum paths are Riemannian geodesics which would not be the case had we used ordinary time.
Synthesis of Five-Bar Slider Mechanism with Variable Topology for Finitely Separated Positions  [PDF]
Umesh M. Daivagna,Shrinivas S. Balli
Advances in Mechanical Engineering , 2011, DOI: 10.1155/2011/697316
Abstract: A method to synthesize a five-bar slider mechanism with variable topology is suggested. Synthesis is carried out in two phases for function generation. In Phase I, synthesis is carried out for three finitely separated positions. In Phase II, it is carried out for two finitely separated positions. A dyadic complex number method is used to write the equations of motion. The method is simple, general and has an increased accuracy over graphical techniques. An application of the five-bar slider mechanism with variable topology is illustrated. 1. Introduction Dimensional synthesis plays a vital role in kinematic synthesis of mechanisms. It deals with the determination of various link dimensions of mechanisms [1]. The variable topology mechanisms are used to meet complex motion requirements through multiple phases [2]. The main purpose of variable topology mechanism is to make synthesis process simpler [3–5]. Four-bar slider crank linkages have been widely used in industrial applications [6]. Many works on five-bar linkages with variable topology mainly target on revolute joint type [3–5]. Though there are works which deal with the five-bar slider crank linkages, they are not commonly found in industries because of their limitations and difficulty in synthesizing [6]. The objective of the present work is to familiarize the five-bar slider mechanism for industrial applications and to make the synthesis of five-bar slider easy. For the purpose, a method known as variable topology is used. The paper deals with the synthesis of an offset five-bar slider with variable topology mechanism and a centric five-bar slider variable topology mechanism. In a way, this paper is the continuation of the work of second author [3–5]. The suggested procedure successfully applied to the synthesis of five-bar slider which has not been tried. The method used in the present work has been found in the previous studies for the planar five-bar and seven-bar mechanisms with only revolute pairs [3–5]. The mechanisms with sliders and so forth are not dealt with. Here is an attempt to use the technique to the mechanisms with prismatic pairs, that is, sliders, where the situations like that of offset slider and, hence, the stretch ratio come into picture. 1.1. An Offset Five-Bar Slider Mechanism A planar offset five-bar slider mechanism has two degrees of freedom. It has one rotary and one linear independent input as shown in Figure 1. A planar five-bar slider mechanism with variable topology is a mechanism which operates as a simple single-degree-of-freedom mechanism in each phase. Figure
Genetic Variability, Correlation and Path Analysis in Rice under Optimum and Stress Irrigation Regimes  [cached]
Mina ABARSHAHR,Babak RABIEI,Habibollah Samizadeh LAHIGI
Notulae Scientia Biologicae , 2011,
Abstract: In order to estimate genetic variability and relationships among some agronomic traits of rice an experiment were conducted with 30 varieties of rice under two irrigation regimes. There were significant differences among the varieties for all traits. Broad-sense heritability varied from 0.05 for brown grain width to 0.99 for plant height and number of spikelet for panicle under optimum irrigation and from 0.1 for brown grain width to 0.99 for plant height. Evaluation of phenotypic and genotypic coefficient of variations (CV) showed that the lowest and highest phenotypic CV under optimum irrigation regime was observed to panicle fertility percentage and paddy yield and genotypic CV was related to brown grain width and plant height, respectively, while under drought stress condition, days to 50% flowering had the lowest phenotypic and genotypic CV and paddy yield and plant height had the highest phenotypic and genotypic CV. Furthermore, the lowest and highest expected genetic advance using selection intensity of 10% (i=1.75) were evaluated for brown grain width and plant height under optimum irrigation regime, respectively. Path analysis for paddy yield indicated that the number of spikelet per panicle and flag leaf length had positive direct effects and days to complete maturity and plant height had negative direct effects on paddy yield under optimum irrigation condition, while flag leaf width and number of filled grains per panicle had positive direct effects and days to 50% flowering had negative direct effect on paddy yield under drought stress condition.
Optimal synthesis of a four-bar linkage by method of controlled deviation
Bulatovi? Radovan R.,?or?evi? Stevan R.
Theoretical and Applied Mechanics , 2004, DOI: 10.2298/tam0404265b
Abstract: This paper considers optimal synthesis of a four-bar linkage by method of controlled deviations. The advantage of this approximate method is that it allows control of motion of the coupler in the four-bar linkage so that the path of the coupler is in the prescribed environment around the given path on the segment observed. The Hooke-Jeeves’s optimization algorithm has been used in the optimization process. Calculation expressions are not used as the method of direct searching, i.e. individual comparison of the calculated value of the objective function is made in each iteration and the moving is done in the direction of decreasing the value of the objective function. This algorithm does not depend on the initial selection of the projected variables. All this is illustrated on an example of synthesis of a four-bar linkage whose coupler point traces a straight line, i.e. passes through sixteen prescribed points lying on one straight line. .
Measuring higher-order interferences with a five-path interferometer  [PDF]
Thomas Kauten,Robert Keil,Thomas Kaufmann,Benedikt Pressl,Gregor Weihs
Physics , 2015,
Abstract: Within the established theoretical framework of quantum mechanics, interference always occurs between pairs of trajectories. Higher order interferences with multiple constituents are, however, excluded by Born's rule and can only exist in generalized probabilistic theories. Thus, high-precision experiments searching for such higher order interferences are a powerful method to test the validity of the Born rule and distinguish between quantum mechanics and more general theories. Here, we perform such a test in optical multi-path interferometers. Our results permit to rule out the existence of higher order interference terms to an extent which is more than four orders of magnitude smaller than the expected pairwise interference, refining previous bounds by two orders of magnitudes. This establishes the hitherto tightest constraints on generalized interference theories.
Optimum Design of a Five-Phase Permanent Magnet Synchronous Motor for Underwater Vehicles by use of Particle Swarm Optimization  [cached]
Reza Ilka,S. Asghar Gholamian
TELKOMNIKA : Indonesian Journal of Electrical Engineering , 2012, DOI: 10.11591/telkomnika.v10i5.1176
Abstract: Permanent magnet synchronous motors are efficient motors which have widespread applications in electric industry due to their noticeable features. One of the interesting applications of such motors is in underwater vehicles. In these cases, reaching to minimum volume and high torque of the motor are the major concern. Design optimization can enhance their merits considerably, thus reduce volume and improve performance of motors. In this paper, a new method for optimum design of a five-phase surface-mounted permanent magnet synchronous motor is presented to achieve minimum loss and magnet volume with an increased torque. A multi-objective optimization is performed in search for optimum dimensions of the motor and its permanent magnets using particle swarm optimization. The design optimization results in a motor with great improvement regarding the original motor. Finally, finite element analysis is utilized to validate the accuracy of the design.
Comparison of Magnetic-Geared Permanent-Magnet Machines
Xianglin Li;Kwok-Tong Chau;Ming Cheng;Wei Hua
PIER , 2013, DOI: 10.2528/PIER12080808
Abstract: With the advent of magnetic gears, researchers have developed a new breed of permanent-magnet machines. These magnetic-geared permanent-magnet machines artfully incorporate the concept of magnetic gearing into the permanent-magnet machines, leading to achieve low-speed high-torque direct-drive operation. In this paper, a quantitative comparison of three viable magnetic-geared permanent-magnet machines is firstly performed, hence revealing their key features, merits, demerits and applications. Initially, the development of the magnetic gears, including the converted topologies and field-modulated topologies, is reviewed. Then, three viable magnetic-geared permanent-magnet machines are identified and discussed. Consequently, the corresponding performances are analyzed and quantitatively compared. The results and discussions form an important foundation for research in low-speed high-torque direct-drive systems.
Study of $qqqc\bar{c}$ five quark system with three kinds of quark-quark hyperfine interaction  [PDF]
S. G. Yuan,K. W. Wei,J. He,H. S. Xu,B. S. Zou
Physics , 2012, DOI: 10.1140/epja/i2012-12061-2
Abstract: The low-lying energy spectra of five quark systems $uudc\bar{c}$ (I=1/2, S=0) and $udsc\bar{c}$ (I=0, S=-1) are investigated with three kinds of schematic interactions: the chromomagnetic interaction, the flavor-spin dependent interaction and the instanton-induced interaction. In all the three models, the lowest five quark state ($uudc\bar{c}$ or $udsc\bar{c}$) has an orbital angular momentum L=0 and the spin-parity $J^{P}=1/2^{-}$; the mass of the lowest $udsc\bar{c}$ state is heavier than the lowest $uudc\bar{c}$ state.
Low-Complexity Sphere Decoding of Polar Codes based on Optimum Path Metric  [PDF]
Kai Niu,Kai Chen,Jiaru Lin
Computer Science , 2013,
Abstract: Sphere decoding (SD) of polar codes is an efficient method to achieve the error performance of maximum likelihood (ML) decoding. But the complexity of the conventional sphere decoder is still high, where the candidates in a target sphere are enumerated and the radius is decreased gradually until no available candidate is in the sphere. In order to reduce the complexity of SD, a stack SD (SSD) algorithm with an efficient enumeration is proposed in this paper. Based on a novel path metric, SSD can effectively narrow the search range when enumerating the candidates within a sphere. The proposed metric follows an exact ML rule and takes the full usage of the whole received sequence. Furthermore, another very simple metric is provided as an approximation of the ML metric in the high signal-to-noise ratio regime. For short polar codes, simulation results over the additive white Gaussian noise channels show that the complexity of SSD based on the proposed metrics is up to 100 times lower than that of the conventional SD.
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