http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
A Novel Linearization Method of Sin/Cos Sensor Signals Used for Angular Position Determination
Dragan ?ivanovi?,Jelena Luki?,Dragan Deni? 대한전기학회 2014 Journal of Electrical Engineering & Technology Vol.9 No.4
In this paper a novel method for angular position determination using sensors with sin / cos output and without an excitation signal, is presented. The linearization of the sensor transfer characteristic and digitalization of the measurement results are performed simultaneously with a goal to increase the measurement resolution. This improvement is particularly important for low angular velocities, and can be used to increase the resolution of incremental Hall, magnetic and optical sensors. This method includes two phases of sin/cos signal linearization. In the first linearization phase the pseudo-linear signal is generated. The second linearization phase, executed by the two-stage piecewise linear ADC, is an additional linearization of the pseudo-linear signal. Based on the LabVIEW software simulations of the proposed method, the contribution of each processing phase to a final measurement error is examined. After the proposed method is applied within 2π [rad] range, the maximal nonlinearity is reduced from 0.3307 [rad] (18.9447°) to 3·10-4 [rad] (0.0172°).
Parameters of Calcium Metabolism Fluctuated during Initiation or Changing of Antipsychotic Drugs
Dragan R. Milovanovic,Marijana Stanojevic Pirkovic,Snezana Zivancevic Simonovic,Milovan Matovic,Slavica Djukic Dejanovic,Slobodan M. Jankovic,Dragan Ravanic,Milan Petronijevic,Dragana Ignjatovic Risti 대한신경정신의학회 2016 PSYCHIATRY INVESTIGATION Vol.13 No.1
ObjectiveaaSerum parameters of calcium homeostasis were measured based on previously published evidence linking osteoporotic fractures and/or bone/mineral loss with antipsychotics. MethodsaaProspective, four-week, time-series trial was conducted and study population consisted of patients of both genders, aged 35-85 years, admitted within the routine practice, with acute psychotic symptoms, to whom an antipsychotic drug was either introduced or substituted. Serial measurements of serum calcium, phosphorous, magnesium, 25(OH)D, parathyroid hormone, calcitonin, osteocalcin and C-telopeptide were made from patient venous blood samples. ResultsaaCalcium serum concentrations significantly decreased from baseline to the fourth week (2.42±0.12 vs. 2.33±0.16 mmol/L, p=0.022, n=25). The mean of all calcemia changes from the baseline was -2.6±5.7% (-24.1 to 7.7) with more decreases than increases (78 vs. 49, p=0.010) and more patents having negative sum of calcemia changes from baseline (n=28) than positive ones (n=10) (p=0.004). There were simultaneous falls of calcium and magnesium from baseline (63/15 vs. 23/26, p<0.001; OR=4.75, 95% CI 2.14–10.51), phosphorous (45/33 vs. 9/40, p<0.001; 6.06, 2.59–14.20) and 25(OH)D concentrations (57/21 vs. 13/35, p<0.001; 7.31, 3.25–16.42), respectively. Calcemia positively correlated with magnesemia, phosphatemia and 25(OH)D values. Parathyroid hormone and C-telopeptide showed only subtle oscillations of their absolute concentrations or changes from baseline; calcitonin and osteocalcin did not change. Adjustment of final calcemia trend (depletion/accumulation) for relevant risk factors, generally, did not change the results. ConclusionaaIn patients with psychotic disorders and several risks for bone metabolism disturbances antipsychotic treatment was associated with the decrease of calcemia and changes in levels of the associated ions.
A Novel Linearization Method of Sin/Cos Sensor Signals Used for Angular Position Determination
Zivanovi, Dragan,Lukic, Jelena,Denic, Dragan The Korean Institute of Electrical Engineers 2014 Journal of Electrical Engineering & Technology Vol.9 No.4
In this paper a novel method for angular position determination using sensors with sin/cos output and without an excitation signal, is presented. The linearization of the sensor transfer characteristic and digitalization of the measurement results are performed simultaneously with a goal to increase the measurement resolution. This improvement is particularly important for low angular velocities, and can be used to increase the resolution of incremental Hall, magnetic and optical sensors. This method includes two phases of sin/cos signal linearization. In the first linearization phase the pseudo-linear signal is generated. The second linearization phase, executed by the two-stage piecewise linear ADC, is an additional linearization of the pseudo-linear signal. Based on the LabVIEW software simulations of the proposed method, the contribution of each processing phase to a final measurement error is examined. After the proposed method is applied within $2{\pi}$ [rad] range, the maximal nonlinearity is reduced from 0.3307 [rad] ($18.9447^{\circ}$) to $3{\cdot}10^{-4}$ [rad] ($0.0172^{\circ}$).
On FEM modeling of piezoelectric actuators and sensors for thin-walled structures
Dragan Marinkovic,Zoran Marinkovic 국제구조공학회 2012 Smart Structures and Systems, An International Jou Vol.9 No.5
Thin-walled adaptive structures render a large and important group of adaptive structures. Typical material system used for them is a composite laminate that includes piezoelectric material based sensors and actuators. The piezoelectric active elements are in the form of thin patches bonded onto or embedded into the structure. Among different types of patches, the paper considers those polarized in the thickness direction. The finite element method (FEM) imposed itself as an essential technical support for the needs of structural design. This paper gives a brief description of a developed shell type finite element for active/adaptive thin-walled structures and the element is, furthermore, used as a tool to consider the aspect of mesh distortion over the surface of actuators and sensors. The aspect is of significance for simulation of behavior of adaptive structures and implementation of control algorithms.
Dragan Ribarić 국제구조공학회 2016 Structural Engineering and Mechanics, An Int'l Jou Vol.59 No.6
We employ the so-called problem-dependent linked interpolation concept to develop two cubic 4-node quadrilateral plate finite elements with 12 external degrees of freedom that pass the constant bending patch test for arbitrary node positions of which the second element has five additional internal degrees of freedom to get polynomial completeness of the cubic form. The new elements are compared to the existing linked-interpolation quadratic and nine-node cubic elements presented by the author earlier and to the other elements from literature that use the cubic linked interpolation by testing them on several benchmark examples.
Dragan, Olena,Berher, Alina,Plets, Ivan,Biloshkurska, Nataliia,Lysenko, Nataliia,Bovkun, Olha International Journal of Computer ScienceNetwork S 2021 International journal of computer science and netw Vol.21 No.7
The aim of the study is to implement a factor analysis of the determinants of pricing in a state-regulated competitive market using economic and mathematical modelling methods and to develop ways to improve the pricing environment of the market under study. The purpose of the work defines the main objectives: (i) to investigate the features of the competitive model of the Ukrainian flour market; (ii) to analyse the current price conjuncture of the flour market and the dynamics of the main determinants of pricing; (iii)to develop ways of improving the price situation on the flour market on the basis of the factor analysis on the results of economic and mathematical modelling. In order to ensure the reliability and validity of the research results, the following methods were applied: the logical-dialectical method of scientific knowledge in the study of the main theoretical aspects of flour market functioning, the method of logical generalisation and synthesis, comparison, factor analysis, correlation and regression analysis, the graphical method, etc. It has been shown that pricing in a state-regulated competitive market has its own characteristics. For example, in the flour market the price of goods cannot be influenced by producers (sellers) by any methods, therefore determinants of pricing by indirect influence have been taken into account. The five-factor power model of wheat flour price has been constructed. It was substantiated that the price of wheat flour in Ukraine is mostly influenced by consumer price index (0.92 %). The received complex model of wheat flour price may be used also for medium-term forecasting and working out the ways of price formation optimization in the flour market.
Soft-Switching Resonant Conversion with IGCT
Dragan Stamenkovic,Drazen Dujic 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
In the area of medium voltage DC-DC conversion, series resonant converter is an attractive topology for implementation of the solid state DC transformer. Applying integrated gate controlled thyristor as a switch, it is possible to obtain very low conduction losses, while greatly lowering the switching losses by proper use of this converter topology. Continuous operation of the IGCT under low current turn-off and zero voltage turn-on is explored throughout this paper, with the emphasis of the proper dead-time selection, critical parameter limiting the increase of switching frequency while keeping the turn-off losses low. Theoretical assumptions and conclusions are supported by experimental results obtained from a dedicated test setup designed to emulate the operating conditions present in series resonant converter.
Right and left Fredholm operator matrices
Dragan S. Djordjevic,Milica Z. Kolundzija 대한수학회 2013 대한수학회보 Vol.50 No.3
We consider right and left Fredholm operator matrices of the form [A C T S], which are linear and bounded on the Banach space Z = X Y .