We know that most of the numerical methods for solving ordinary differential equations (ODEs) are based on iterative techniques or Taylor expansion techniques. In this paper, take three-point boundary value problems (BVPs) of linear second-order ODEs for example, we try to study the numerical solutions of ODEs from a new perspectivel-machine learning. By means of the idea of least squares support vector regression (LSSVR), we propose a new numerical solving method for three-point BVPs of linear second-order ODEs. From the derivative process of the proposed method, we can see that it has generality and can be used for solving some other kinds of ODEs. In order to verify the effectiveness of the proposed method, we perform a series of comparative experiments with four specific linear second-order ODEs. Experimental results show that the proposed method is a effective menthod.
In recent years, due to the relation between cognitive control and mathematical concept of control dynamical systems, there has been growing interest in the descriptive analysis of complex networks with linear dynamics, permeating many aspects from everyday life, obtaining considerable advances in the description of their structural and dynamical properties. Nevertheless, much less effort has been devoted to studying the controllability of the dynamics taking place on them. Concretely, for complex systems is of interest to study the exact controllability, this measure is defined as the minimum set of controls that are needed to steer the whole system toward any desired state. In this paper, a revision of controllability concepts is presented and provides conditions for exact controllability for the multiagent systems
This paper presents a simplified routing wire for anti-parallel configuration. This scheme is applied to parallel feedings to a circular polarization 16-antenna array. The unit antenna is composed of three elements of feed and reactance elements, and ground plate. Then, a configuration of 16-antenna array is presented. A 4- antenna array composed of smoothed routing wire is set at each quadrant. The directions of each 4-antenna array at the first and the second quadrants are parallel, and anti-parallel at the third and the fourth quadrants. A grounded circular cylinder is set at the peripheral of 16-antenna array. The characteristics of the proposed antenna array are obtained by 3D computer simulation. It was found that this scheme is applicable to wideband and practical systems.
This article is devoted to the measurement and analysis of passive optical networks PON (Passive Optical Network) with and without utilization PLC (Planar Lightwave Circuit) splitter. The real network simulation is done as a prevention of complications in the final construction of optical network, which is designed for specific user requirements. The article describes connections between two campuses. The optical networks were first designed, and afterwards simulated and implemented. These buildings are connected by single mode fiber G.652.D (706.4 m) terminated with SC / PC and optical splitter (PLC) with the ratio of 1:8 and insertion loss of 10.8 dB. Main contribution of this paper was comparison of the difference between measured parameters of optical networks and demonstration when it is better to use an optical splitter, and when it is better to connect the fibre directly.
This paper introduces a new voltage-mode multifunction filter employing single current differencing transconductance amplifier (CDTA) and its MOS-C implementation. The proposed filter topology can synthesize all filter types, i.e. low-pass, high-pass, band-pass, band-stop and all-pass filters by modifying three admittances and gain of the filters can be adjusted independently by a resistor. Central frequency of the filters can be tuned electronically. The operability of the circuit is confirmed in close agreement with the theory by PSPICE simulation software using TSMC 0.18 micron CMOS model parameters at ±0.9 V supply voltage. The proposed circuit is suitable for integration technique through the MOS-C implementation.
The work consists of development of the clarified model of a gas-diesel device by taking into account its design features and the influence of the turbo-supercharger. The analysis of the influence of the turbine on the physical processes occurring in the gas-diesel device, on the basis of which positive feedback on the torque on the shaft of the gas-diesel device is introduced, has been carried out. The process of parametric optimization of the PID-controller of the gas-diesel device has been automated to ensure high performance of the control quality in dynamic modes of its operation. As a result of modeling, oscillograms of transients before and after optimization of the controller have been obtained.
An analysis of a BJT phase shift amplifier is proposed in a detail polynomial form. The numerator and denominator polynomial form are derived which can be seen as a symbolic coefficient which are multiplied with complex frequencies of the order of the polynomial. A detail analysis is very laborious but it is presented some of the coefficients which are a function of the small signal parameters of the equivalent circuit such as a transconductance, output resistor, base spreading resistor, pi resistor, myu resistor and two parasitic capacitances, passive resistor for biasing, passive capacitors and resistors which are the core circuit of the phase shift networks. After dc operating point are designed as a function of the current consumption. All small signal parameters of the transistors of the phase shift amplifier are designed as a function of the current consumption. The BJT phase shift frequency response can be plotted by a polynomial form which can be calculated by MATLAB. The BJT phase shift amplifier may not worked as a phase shift oscillator without the input impedance formulas.
This paper deals with a control of a vertical dynamics in the presence of nonlinear friction in a\r\nrobotic mechanism. The control structure, which is taken into consideration, is the Sliding Mode Control\r\n(SMC). Using this control technique, it is possible to show the asymptotical stability of the trajectory to be\r\ntracked. Simulation results show the effectiveness of the proposed control technique.
Pythagorean fuzzy sets (PFS) has much stronger ability than intuitionistic fuzzy set (IFS) to manage the uncertainty in real-world multi-criteria decision-making problems. Current research develops a Pythagorean fuzzy TOPSIS approach for formation and representing of expert’s knowledge on the parameters of facility location planning in extreme environment. In this approach, we propose a score function based comparison method to identify the Pythagorean fuzzy positive ideal solution and the Pythagorean fuzzy negative ideal solution. Based on the constructed fuzzy TOPSIS aggregation a new objective function is formulated. Constructed criterion maximizes service centers' selection index. This criterion together with second criterion - minimization of number of selected centers creates the multi-objective facility location set covering problem. The approach is illustrated by the simulation example of emergency service facility location planning for a city in Georgia. More exactly, the example looks into the problem of planning fire stations locations to serve emergency situations in specific demand points – critical infrastructure objects
Solar energy is a kind of renewable energy which should be given the most importance nowadays and will always be sustainable. It has a tendency to develop due to the awareness of consumable resources and environmental awareness. Nevertheless, solar energy is still lagging behind fossil-based energy production types. In this study, the simulation results of the two solar power plants in the Eastern Anatolian Region and the Black Sea Region are compared with the geographic and meteorological characteristics. In addition, real field conditions and analysis results are compared with 1-year data.
The problem of applying the maximum principle for finding an optimal control for the parameters in simulation for a variety of engineering and industrial systems and processes is considered. The focus is on such systems where the control of a system is difficult or practically impossible due to unknown model of system or some other uncertainties in each particular case. The procedure is constructed that converges and allows obtaining the approximation and optimal control of the system in a finite number of steps with a given accuracy. The theorem about the procedure is proved and illustrative examples are given. Some features of the application of the proposed algorithm to the real problems of simulation control are discussed like the optimal number of points dividing the temporal interval and the tasks for future investigation
Flexible supercapacitor (SC) that possess high pulse power and energy density with long lifetime is an essential need for future applications. Moreover, gel polymer liquid-based SC presents many superior advantages over aqueous organic/inorganic electrolytes such as safety, long operation temperature range, solid-state appearance and relatively high voltage window. Therefore, Silver decorated reduced graphene oxide (RGO) coupled with developed (H 3 PO 4 /PVA/GO/ polyaniline) gel polymer were used to fabricate the SCs, which offers flexibility, durability, safety and ability to apply high scan rates. Influence of different ratios of silver to GO weight on specific capacitance and performance were studied. The SCs were prepared by printing technique (layer by layer) then peeled of the basic plastic substrate. After that, silver thin films were sputtered on both sides of the printed SCs as the current collectors using a shadow mask. Interestingly, a specific capacitance of about 164 F/g correlated with 29.5 Wh/Kg energy were achieved correlated with using H 3 PO 4 that is considered to be a weak electrolyte. Moreover, 0.5 ohm represents the smallest electric series resistance that would directly affect the power of the fabricated solid-state SC. The composite was studied using Raman spectroscopy, TEM and XRD, whereas, The VSP-300 potentiostat/galvanostat was used for extensive electrochemical characterizations of the prepared asymmetric SCs.
The method of groping, to find the parameters of a regulator PI, is very tiring, because of that. In this paper, one proposed a PI adaptif regulator with reference model based on the optimization of a criterion performance to apply to the Field-Oriented Control for asynchronous machine
The fast Fourier transform (FFT) based numerical method for thin film magnetization problems in type-II superconductivity has been proposed by Vestgarden and Johansen [Supercond. Sci. Technol. Vol. 25, 2012, 104001]. Our work significantly improves the efficiency of their method and extends it to 3D magnetization problems for bulk superconductors and to stacks of flat thin superconducting films of arbitrary shape, the two configurations of interest for a variety of practical applications. The method is efficient, allows for a highly nonlinear current–voltage relation characterising the superconducting material, and is much easier to implement than the recently proposed approaches based upon the finite element methods. We present solutions to two realistic bulk problems, where superconductors are employed for magnetic shielding and as a magnetic field concentrator (a lens). A rescaled solution to a few-film-stack problem was used to obtain an accurate approximation to the anisotropic homogenization limit of magnetization of a densely packed stack of many films.
This paper presents the new methodology and CAD programs to detect two serious faults in VLSI design: HV/LV connection faults and floating gate faults. A hierarchical circuit netlist is flattened in order to trace the connectivity of MOS devices in hierarchically designed circuits. Programs were coded in Python and table-look up techniques were used to speed up the program run. Program flows and specification files are discussed. Specification file commands allowed designers to waive non-critical faults after reviewing them in the design. We developed GUI capability for highlighting nets in the schematic window. GUI helps designers review and fix faults in Cadence design environment. Programs and GUI capability have been applied in one industry project.
Multibond graph models has been introduced for the modelling of multibody systems for Breedveld and Tiernego [2, 5]. However, these publised papers do not give general methodologies to obtain the mathematical models. Hence, a junction structure of multibond graph models is proposed. In addition, the steady state response of systems modelled by multibond graphs in a derivative causality assignment is obtained. An example applying the propose methodology is solved.
To meet the needs of the IEEE Standard 1139-2008, this paper suggests using the recently designed iterative unbiased finite impulse response (UFIR) filtering algorithm to estimate clock state via measurement of the time interval error (TIE) on an interval of N most recent past points. The algorithm has the Kalman filter (KF) form. But, unlike the KF, requires neither the noise statistics nor the initial values. Because noise in clocks has colored Gaussian components (not white, as required by the KF), the UFIR filter demonstrates higher robustness and becomes optimal when N ≫ 1. Applications are given for state estimation in an ovenized crystal clock and error prediction in a masted clock. Based upon extensive experimental investigations, we show that the UFIR algorithm outperforms the KF, because the clock covariance matrix cannot be specified correctly in view of the colored noise.
Common controlling strategies of fuel cells regulate parameters like the flow rates, pressures, temperatures, and relative humidities of the supplied gases. These strategies have a slow control effect on the fuel cell output voltage, especially at high dynamic loads, which is why fuel cell voltage and power drops for several seconds to minutes after a load step. Today, an oversizing of fuel cell systems is necessary to meet the requirements of dynamic load profiles. This paper deals with the design and implementation of an electric field modifier (EFM) control unit into fuel cells to enable the regulation of an additional control parameter, which is considerably faster than the common parameters. The EFM control unit consists of EFM electrodes that are placed directly on or in the membrane of polymer exchange membrane fuel cells and are connected to an external controllable voltage source. Possible electrical connections and actuating signals are presented. Deduced advantages include a better dynamic fuel cell system voltage behavior, a cost- and weight-optimized on-board grid integration, and a prolonged membrane durability.
This paper designs two kinds of recursive least-squares Wiener fixed-point smoothers based on an innovation approach in linear discrete-time stochastic systems. It is assumed that the signal is observed with additive white noise. The proposed fixed-point smoothers require the information of the observation matrix, the system matrix for the state variable, related with the signal, the variance of the state variable, the cross-variance function of the state variable with the observed value and the variance of the white observation noise.
The optimal LLC resonant converter with the great performance in wide range of load and frequency is described in this paper. The output voltage can be remained stable by changing the frequency in different input/load conditions. It can realize the high efficiency and high density. The LLC resonant converter is simplified as the FMA model firstly to analyse its operating characteristics. These characteristics then can be verified by simulation results. The practical circuit is also built on PCB to prove it work properly.
