This paper deals with the global position control problem of robot manipulators in joint space, a new family of control schemes consisting of a suitable combination of hyperbolic functions is presented. The proposed control family includes a large class of bounded hyperbolic-type control schemes to drive both position error and derivative action terms plus gravity compensation. To ensure global asymptotic stability of closed-loop system equilibrium point, we propose an energy-shaping based strict Lyapunov function. To verify the efficiency of the proposed control algorithm, an experimental comparative analysis between the well known unbounded linear PD control and three hyperbolic-type control schemes of the proposed family on a three degrees of freedom direct-drive robot manipulator is analysed.
We investigate the category $\text{mod}\Lambda $ of finite length modules over the ring $\Lambda =A\otimes _k\Sigma $, where $\Sigma $ is a V-ring, i.e. a ring for which every simple module is injective, $k$ a subfield of its centre and $A$ an elementary $k$-algebra. Each simple module $E_j$ gives rise to a quasiprogenerator $P_j=A\otimes E_j$. By a result of K. Fuller, $P_j$ induces a category equivalence from which we deduce that $\text{mod}\Lambda \simeq \coprod _jbad hbox P_j$. As a consequence we can (1) construct for each elementary $k$-algebra $A$ over a finite field $k$ a nonartinian noetherian ring $\Lambda $ such that $\text{mod}A\simeq \text{mod}\Lambda $, (2) find twisted versions $\Lambda $ of algebras of wild representation type such that $\Lambda $ itself is of finite or tame representation type (in mod), (3) describe for certain rings $\Lambda $ the minimal almost split morphisms in $\text{mod} \Lambda $ and observe that almost all of these maps are not almost split in $\text{Mod}\Lambda $.
In this paper, we demonstrate the computational consequences of making a simple assumption on production cost structures in capacitated lot-size problems. Our results indicate that our cost assumption of increased productivity over time has dramatic effects on the problem sizes which are solvable. Our experiments indicate that problems with more than 1000 products in more than 1000 time periods may be solved within reasonable time. The Lagrangian decomposition algorithm we use does of course not guarantee optimality, but our results indicate surprisingly narrow gaps for such large-scale cases - in most cases significantly outperforming CPLEX. We also demonstrate that general CLSP's can benefit greatly from applying our proposed heuristic.
The paper presents a simple method to check a positiveness of symmetric multivariate polynomials on the unit multi-circle. The method is based on the sampling polynomials using the fast Fourier transform. The algorithm is described and its possible applications are proposed. One of the aims of the paper is to show that presented algorithm is significantly faster than commonly used method based on the semi-definite programming expression.
The absolute gravity measurements are an important tool for reliable monitoring geodynamic phenomena. Based on the experience with the absolute gravimeter FG5#215 (gravimeter of the Center for Earth Dynamics Research), the accuracy of FG5 absolute gravimeters is presented in this study. The instrumental reproducibility of this meter is characterized by the value of 0.7 μGal. Discussed are important environmental effects on gravity measurements, such as atmospheric and hydrological effects, understanding of which is necessary for correct and reliable interpretation of the repeated absolute gravity measurements in geodynamics., Vojtech Pálinkáš, Jakub Kostelecký and Jaroslav Šimek., and Obsahuje bibliografii
This paper discusses an experiment in cognitive psychology called the Linda problem. Firstly, some natural conditions for the correctness of the interpretation of psychological experiments (such as the Linda problem) are formulated. The article is essentially a critique of the interpretation of the results of the Linda problem experiment provided by Kahneman and Tversky as well as – indirectly – their concept of heuristics. It is shown that the interpretation provided by Kahneman and Tversky does not meet the aforementioned conditions for correctness. The main argument is justified utilizing such rules of rationality as conditional probability and Grice’s conversational maxims. It is also pointed out that this argument can be reformulated in terms of the intuitive system of reasoning., Tento příspěvek pojednává o experimentu v kognitivní psychologii nazývaném problém Lindy. Za prvé jsou formulovány některé přírodní podmínky pro správnost interpretace psychologických experimentů (jako je problém Lindy). Článek je v podstatě kritikou interpretace výsledků problému Linda, který poskytli Kahneman a Tversky, stejně jako - nepřímo - jejich pojetí heuristiky. Ukazuje se, že výklad poskytnutý Kahnemanem a Tversky nesplňuje výše uvedené podmínky správnosti. Hlavní argument je odůvodněn použitím takových pravidel racionality jako podmíněné pravděpodobnosti a Griceho konverzačních maxim. Rovněž je zdůrazněno, že tento argument lze přeformulovat z hlediska intuitivního systému uvažování., and Adam Olszewski
The perturbed Laplacian matrix of a graph G is defined as DL = D−A, where D is any diagonal matrix and A is a weighted adjacency matrix of G. We develop a Fiedler-like theory for this matrix, leading to results that are of the same type as those obtained with the algebraic connectivity of a graph. We show a monotonicity theorem for the harmonic eigenfunction corresponding to the second smallest eigenvalue of the perturbed Laplacian matrix over the points of articulation of a graph. Furthermore, we use the notion of Perron component for the perturbed Laplacian matrix of a graph and show how its second smallest eigenvalue can be characterized using this definition., Israel Rocha, Vilmar Trevisan., and Obsahuje seznam literatury
Dieser Artikel erforscht die Quellen, analysiert die Sprache, erötert den historischen Kontext und die Umstände der Entstehung der ruthenischen Übersetzung des Liedes der Lieder aus dem tschechischen. Die Handschrift, die ein Bestandteil einer handschriftlichen Sammlung aus den 15.-16. Jahrhunderten ist, liegt heute in dem Staatlichen Historischen Museum in Moskau unter der Nr. 558 in der Abteilung der Handschriften aus der Bibliothek des Heiligen Synods. Die linguistische und textologische Analyse der Übersetzung, wie auch der handschriftlichen Sammlung im ganzen, legt die Hypothese nahe, daß die Entstehung der ruthenischen Übersetzung des Liedes der Lieder mit der Missionsaktivität der Mönchen - Glagoljaši bei der orthodoxen Bevölkerung südwestlichen Rußlands (Ruthenia) verbunden war. Diese waren von Wladyslaw Jagiello aus dem Emmaus-Kloster in Prag eingeladen worden, um hier die slavische Liturgie "nach dem Gesetz des römischen Hofes" einzuführen.
Matrix polynomials play an important role in the theory of matrix differential equations. We develop a fixed point method to compute solutions of matrix polynomials equations, where the matricial elements of the matrix polynomial are considered separately as complex polynomials. Numerical examples illustrate the method presented.
This paper deals with the application of a fluidized layer of granular material (FLGM) for the direct separation of destabilized impurities during drinking water treatment. Further, it investigates the effect of operation parameters (fluidized layer grain size, technological arrangement, velocity gradient, retention time, dosage of destabilisation reagent and temperature) on the aggregation and separation efficiency of the layer. The tests were carried out in a pilot plant scale. Aluminium sulphate was used as the destabilisation reagent. The highest separation efficiencies were achieved, when the particles entered the fluidized layer immediately after the dosing of the destabilisation reagent, when they had the lowest degree of aggregation. The separation efficiency (ϕ) also increased with increasing velocity gradient and the maximal value was reached at the velocity gradient of about 250 s-1. The most efficient separation of aluminium was achieved at 5 °C, but the effect of temperature on the efficiency of organic matter separation (ϕTOC) was not very significant. The maximal efficiency of separation on the layer grains reached the values ϕAl = 0.81 at the optimal dosage DAl = 1.55 mg L-1 and ϕTOC = 0.31 at the optimal dosage DAl = 2.36 mg L-1. The indisputable advantage of using FLGM for the separation of impurities is that they are intercepted on the layer grains in a form of solid, water-free shell (or coat) with the density of 2450 kg m-3, and there is no need to deal with the sludge dewatering. and Příspěvek se zabývá využitím fluidní vrstvy zrnitého materiálu (FLGM) pro přímou separaci destabilizovaných nečistot při úpravě vody a vlivem provozních parametrů (velikost zrn náplně, technologické uspořádání, gradient rychlosti, doba zdržení, dávka destabilizačního činidla, teplota) na agregační a separační účinnost vrstvy. Testy byly prováděny na poloprovozním modelu fluidní vrstvy. Jako destabilizační činidlo byl použit síran hlinitý. Nejvyšší separační účinnosti byly dosahovány, pokud částice nečistot vstupovaly do fluidní vrstvy bezprostředně po nadávkování destabilizačního činidla, kdy byl jejich stupeň agregace nejnižší. Separační účinnost (ϕ) se také zvyšovala s narůstající hodnotou gradientu rychlosti ve fluidní vrstvě a maximální hodnoty dosáhla při gradientu kolem 250 s-1. Hliník byl nejúčinněji separován při nízké teplotě (5 °C), nicméně na účinnost separace organických látek (ϕTOC) teplota příliš velký vliv neměla. Maximální účinnost separace na zrnech fluidní vrstvy dosáhla hodnot ϕAl = 0,81 při optimální dávce DAl = 1,55 mg L-1 a ϕTOC = 0,31 při optimální dávce DAl = 2,36 mg L-1. Nespornou výhodou využití fluidní vrstvy jako separačního prvku je skutečnost, že nečistoty jsou na zrnech FLGM zachycovány ve formě pevné skořápky (hustota 2450 kg m-3), která neobsahuje kapalnou vodu, a kal tudíž nemusí být odvodňován.