By a paramedial groupoid we mean a groupoid satisfying the equation ax·yb=bx·ya. This equation is, in certain sense, symmetric to the equation of mediality xa·by=xb·ay and, in fact, the theories of both varieties of groupoids are parallel. The present paper, initiating the study of paramedial groupoids, is meant as a modest contribution to the enormously difficult task of describing algebraic properties of varieties determined by strong linear identities (and, especially,of the corresponding simple algebras).
This paper deals with continuous-time Markov decision processes with the unbounded transition rates under the strong average cost criterion. The state and action spaces are Borel spaces, and the costs are allowed to be unbounded from above and from below. Under mild conditions, we first prove that the finite-horizon optimal value function is a solution to the optimality equation for the case of uncountable state spaces and unbounded transition rates, and that there exists an optimal deterministic Markov policy. Then, using the two average optimality inequalities, we show that the set of all strong average optimal policies coincides with the set of all average optimal policies, and thus obtain the existence of strong average optimal policies. Furthermore, employing the technique of the skeleton chains of controlled continuous-time Markov chains and Chapman-Kolmogorov equation, we give a new set of sufficient conditions imposed on the primitive data of the model for the verification of the uniform exponential ergodicity of continuous-time Markov chains governed by stationary policies. Finally, we illustrate our main results with an example.
The biped robot with flat feet and fixed ankles walking down a slope is a typical impulsive dynamic system. Steady passive gaits for such mechanism can be induced on certain shallow slopes without actuation. The steady gaits can be described by using stable non-smooth limit cycles in phase plane. In this paper, it is shown that the robot gaits are affected by three parameters, namely the ground slope, the length of the foot, and the mass ratio of the robot. As the ground slope is gradually increased, the gaits exhibit universal period doubling bifurcations leading to chaos. Meanwhile, the phenomena of period doubling bifurcations also occur by increasing either the foot length or the mass ratio of the robot. Theory analysis and numerical simulations are given to verify our conclusion.
The main goal of this paper is to use traíRc data measured automatically by inductive loops, reduce the dimensionality of measured data vector and apply the reduced data vector for imitation of the traffic operator’s behaviour. The feature vector’s dimensionality is reduced both by Fisher criterion and truncated SVD (singular value decornposition) rnethods. For the operator’s imitation the Laplace classifier is applied.
In this paper, we propose several algorithms for computing parameterizations of NURBS domains (surfaces and volumes) which are motivated by the recent research in isogeometric analysis. We describe methods for finding parameterizations of planar NURBS domains bounded by either a given closed NURBS curve, or four NURBS curves fulfilling compatibility conditions. Further, parameterizations of NURBS volumes of revolution based on two different parameterizations of a disc are presented. The main result of the paper is the formulation of an algorithm for computing parameterizations of the so-called generalized NURBS volumes of revolution. and Obsahuje seznam literatury
Pulse wave analysis permits non-invasive assessment of arterial elasticity indices. The contour varies in different parts of the circulation. It depends on physiological or pathophysiological conditions of the organism. The pathological events like arteriosclerosis or diabetes have a primary effect to the artery elasticity. Hypertension or some heart diseases al so influence the pulse wave velocity and resulted in earlier wave reflections. There are several methods of pulse wave measurements based on different principles and depending on the type of measured pulse wave. The evaluation parameters can be assessed from the time domain, derivations, velocity or frequency domain. The main aim of this review article is to offer a recent overview of pulse wave measurement parameters and main results obtained. The principles of pulse wave measurement and current experience in clinical practice are shortly discussed too., D. Korpas, J. Hálek, L. Doležal., and Obsahuje seznam literatury
The effects of temperatures of 15, 20, 25 and 30°C on the duration of premating and preoviposition periods of Harmonia axyridis reared on the aphid Aphis fabae, were compared in the laboratory. The course of oviposition was monitored at 25°C in females reared on Aphis fabae and the peak of egg laying was recorded at the age of 15 to 45 days. The size of egg groups (batch size), as well as daily and total fecundity was recorded. Half of the total number of eggs was laid in batches of 10-30 eggs. The mean daily and total fecundity reached a maximum of 42 and 1,641.6 eggs, respectively. Adult females oviposited for almost their entire life.
This paper considers a parametric approach for quasi-linear systems by using dynamic compensator and multi-objective optimization. Based on the solutions of generalized Sylvester equations, we establish the more general parametric forms of dynamic compensator and the left and right closed-loop eigenvector matrices, and give two groups of arbitrary parameters. By using the parametric approach, the closed-loop system is converted into a linear constant one with a desired eigenstructure. Meanwhile, it also proposes a novel method to realize multi-objective design and optimization. Multiple performance objectives, containing overall eigenvalue sensitivity, H2 norm, H∞ norm and low compensation gain, are formulated by arbitrary parameters, then robustness and low compensation gain criteria are expressed by a comprehensive objective function which contains each performance index weighted. By utilizing degrees of freedom (DOFs) in arbitrary parameters, we can optimize the comprehensive objective function such that an optimized dynamic compensator is found to satisfy the robustness and low compensation gain criteria. Finally, an example of attitude control of combined spacecrafts is presented which proves the effectiveness and feasibility of the parametric approach.
Diabetes mellitus (DM) is a disease affecting millions of people worldwide, and its medical care brings an economic wear to patients and public health systems. Many efforts have been made to deal with DM, one of them is the full-automation of insulin delivery. This idea consists in design a closed-loop control system to maintain blood glucose levels (BGL) within normal ranges. Dynamic models of glucose-insulin-carbohydrates play an important role in synthesis of control algorithms, but also in other aspects of DM care, such as testing glucose sensors, or as support systems for health care decisions. Therefore, there are several mathematical models reproducing glycemic dynamics of DM, most of them validated with nominal parameters of standardized patients. Nevertheless, individual patient-oriented models could open the possibility of having closed-loop personalized therapies. This problem can be addressed through the information provided by open-loop therapy based on continuous glucose monitoring and subcutaneous insulin infusion. This paper considers the problem of identifying particular parameters of a compartmental model of glucose-insulin dynamics in DM; the goal is fitting the model response to historical data of a diabetic patient collected during a time period of her/his daily life. At this time, Sorensen model is one of the most complete compartmental models representing the complex dynamics of the glucose-insulin metabolism. This is a system of 19 ordinary differential equations (ODEs), thus the identification of its parameters is a non-easy task. In this contribution, parameter identification was performed via three evolutionary algorithms: differential evolution, ant colony optimization and particle swarm optimization. The obtained results show that evolutionary algorithms are powerful tools to solve problems of parametric identification. Also, a comparative analysis of the three algorithms was realized throw a wilcoxon sign-rank test, in which colony optimization had the better performance. The model obtained with the estimated parameters could be used to in type 1 diabetes mellitus (T1DM) care, such as in the design of full-automation of insulin infusion.
Úvod: Rozsah nádoru a kvalita jeho chirurgického odstranění patří k hlavním prognostickým faktorům v léčbě karcinomu rekta. Počet pooperačních lokálních recidiv závisí na úplnosti odstranění mezorekta – TME (total mesorectal excision) – a dosažení bezpečných resekčních okrajů bez nádoru. Provedení a kvalita operace záleží na předoperační diagnostice a detekci rizikových míst na rektu a mezorektu, na chirurgické schopnosti výkon správně provést a na patologickém vyšetření, hodnotícím úplnost odstranění nádoru v parametrech resekčních okrajů včetně cirkumferentního (CRO) a kompletnost mezorektální excize. Cílem práce bylo zavést a standardizovat metodu hodnocení kvality chirurgického výkonu − mezorektální excize – v léčbě karcinomu rekta hodnocením resekčních okrajů včetně CRO a kompletnosti excize. Metody: Studie měla dvě části. V první, retrospektivní části multicentrické studie byly v sestavě 288 pacientů analyzovány jednotlivé dílčí parametry diagnostiky, operací a histologického vyšetření karcinomu rekta, identifikována kritická místa a připraven jednotný protokol sledování. Ve druhé, prospektivní části studie byla v sestavě 600 pacientů tato data sledována parametricky a byla hodnocena kvalita TME ve vztahu k onkologickému výsledku léčby. Výsledky: V předoperační diagnostice se zvýšil podíl pacientů, kterým byl proveden restaging po neoadjuvantní léčbě z 60,0 % na 81,7 %. Podíl resekátů, u nichž nebyla hodnocena kvalita excize mezorekta, se snížil z 52,9 % v retrospektivní části na 22,8 % v části prospektivní. Podíl kompletních excizí mezorekta se zvýšil z 22,6 % na 26,0 %, podíl téměř kompletních excizí se zvýšil z 10,1 % v retrospektivní části na 24,0 % v prospektivní části studie. Závěr: Zavedení parametrického sledování do rutinní praxe zvýšilo kvalitu předléčebné a předoperační diagnostiky, vyšetření resekátu patologem a vlivem zpětnovazebné informace také kvalitu chirurgického výkonu., Introduction: Tumour size and the quality of its complete surgical removal are the main prognostic factors in rectal cancer treatment. The number of postoperative local recurrences depends on whether the mesorectum has been completely removed – total mesorectal excision (TME) – and whether tumour-free resection margins have been achieved. The surgery itself and its quality depend on the accuracy of preoperative diagnosis and detection of risk areas in the rectum and mesorectum, on the surgeon’s skills, and finally on pathological assessment evaluating whether complete tumour excision has been accomplished including circumferential margins of the tumour, and whether mesorectal excision is complete. The aim of our study was to implement and standardize a new method of evaluation of the quality of the surgical procedure – TME – in rectal cancer treatment using an assessment of its circumferential margins (CRO) and completeness of the excision. Methods: The study consisted of two parts. The first, multi-centre retrospective phase with 288 patients analysed individual partial parameters of the diagnosis, operations and histological examinations of the rectal cancer. Critical points were identified and a unified follow-up protocol was prepared. In the second, prospective part of this study 600 patients were monitored parametrically focusing on the quality of the TME and its effect on the oncological treatment results. Results: The proportion of patients with restaging following neoadjuvant therapy increased from 60.0% to 81.7% based on preoperative diagnosis. The number of specimens missing an assessment of the mesorectal excision quality decreased from 52.9% in the retrospective part of to the study to 22.8% in the prospective part. The proportion of actually complete TMEs rose from 22.6% to 26.0%, and that of nearly complete TMEs from 10.1% to 24.0%. Conclusion: The introduction of parametric monitoring into routine clinical practice improved the quality of pre-treatment and preoperative diagnosis, examination of the tissue specimen, and consequently improved quality of the surgical procedure was achieved., and J. Hoch, A. Ferko, M. Bláha, A. Ryška, I. Čapov, L. Dušek, J. Feit, M. Grega, M. Hermanová, E. Hovorková, R. Chmelová, Z. Kala, D. Klos, R. Kodet, D. Langer, D. Hadži-Nikolov, J. Örhalmi, J. Páral, M. Tichý, I. Tučková, M. Vjaclovský, P. Vlček