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Input Impedance (input + impedance)
Selected AbstractsApplication of FIR-neural network on finite difference time domain technique to calculate input impedance of microstrip patch antennaINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2010Dhruba C. Panda Abstract Finite impulse response artificial neural network (FIR-ANN) is used for speeding up the FDTD. The FIR-ANN based FDTD (Neuro FDTD) is used to calculate input impedance of coaxial fed stacked microstrip patch antenna. Input impedance obtained by Neuro FDTD and FDTD are compared. It has been observed that Neuro FDTD provides same result with less number of iteration than compared to FDTD. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source] Experimental investigation of radiation properties of an antenna embedded in low permittivity thin-wire-based metamaterialMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2006Davor Bonefa Abstract Experimental results regarding the increase in directivity and gain of an antenna embedded in low-permittivity two-dimensional anisotropic thin-wire-based metamaterial are presented. As expected, increase in directivity and gain has been observed. The effect of main beam splitting with frequency increase, predicted by theoretical analysis, has been confirmed. The influence of the number of layers forming the metamaterial on the radiation pattern and gain has been investigated. Input impedance was measured both as a function of frequency and of the number of wire layers forming the metamaterial. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 2581,2586, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21994 [source] Arterial stiffening and cardiac hypertrophy in a new rat model of type 2 diabetesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 1 2006K.-C. Chang Abstract Background, We determined the effects of NIDDM on haemodynamic parameters describing arterial wall elasticity and cardiac hypertrophy in rats administered streptozotocin (STZ) and nicotinamide (NA), using the aortic impedance analysis. Methods, Male Wistar rats at 2 months were administered intraperitoneally 180 mg kg,1 of NA, 30 min before an intravenous injection of 50 mg kg,1 STZ, to induce type 2 diabetes. The STZ-NA rats were divided into two groups, 4 weeks and 8 weeks after induction of diabetes, and compared with untreated age-matched controls. Pulsatile aortic pressure and flow signals were measured by a high-fidelity pressure sensor and electromagnetic flow probe, respectively, and were then subjected to Fourier transformation for the analysis of aortic input impedance. Results, In each diabetic group, the experimental syndrome was characterized by a moderate and stable hyperglycaemia and a relative deficiency of insulin secretion. However, the 8-week but not the 4-week STZ-NA diabetic rats showed a decrease in cardiac output in the absence of any significant changes in mean aortic pressure, having increased total peripheral resistance. The diabetic syndrome at 8 weeks also contributed to an increase in aortic characteristic impedance, from 1·49 ± 0·33 (mean ± SD) to 1·95 ± 0·28 mmHg s mL,1 (P < 0·05), suggesting a detriment to the aortic distensibility in NIDDM. Meanwhile, the STZ-NA diabetic animals after 8 weeks had an increased wave reflection factor (0·46 ± 0·09 vs. 0·61 ± 0·13, P < 0·05) and decreased wave transit time (25·8 ± 3·8 vs. 20·6 ± 2·8 ms, P < 0·05). Ratio of the left ventricular weight to body weight was also enhanced in the 8-week STZ-NA diabetic rats. Conclusion, The heavy intensity with early return of the pulse wave reflection may augment systolic load of the left ventricle coupled to the arterial system, leading to cardiac hypertrophy in the rats at 8 weeks after following STZ and NA administration. [source] High-frequency behavior of power inductor windings using an accurate multiconductor transmission line model: input impedance evaluationEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2008J. A. Brandão Faria Abstract This research and tutorial paper is the second part of a work dedicated to the analysis and computation of the electromagnetic behavior of inductor windings operating at high-frequency regimes,a critical issue for very fast transient overvoltage studies. The inductor winding, wound around a ferromagnetic core, containing a total number of N dielectric coated cylindrical turns, is modeled by using a multiconductor transmission line (MTL) approach (proximity effects being accounted) whose constitution and characterization was presented in a former paper. In the present work, we make use of the R, G, L, and C constitutive matrices of the structure in order to develop a modal analysis technique-based formulation aimed at the evaluation of the winding's input impedance in the frequency-domain. Results obtained show that the input impedance critically depends not only on the number of layers of the winding but also, and, more importantly, on the frequency, where resonance phenomena play a key role. Frequency-domain analysis is complemented with simulation results in the time-domain that clearly illustrate how critical and sensitive the system response can be under minute changes of the winding's excitation current. Copyright © 2007 John Wiley & Sons, Ltd. [source] High-frequency Impedance and Sensitivity of Micro-fluxgate Sensors Fabricated with Cobalt Base Amorphous FilmsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 4 2008Kwang-Ho Shin Non-member Abstract Micro-fluxgate sensors 2 mm long, 1.5 mm wide were fabricated with CoZrNb amorphous films. Their high-frequency input/output impedance was measured and evaluated to investigate whether the sensor output and/or sensitivity could be estimated by the complex impedance, especially the reactance. The output reactance changed from 11.1 to 6.1 ohm at 8 MHz by applying the external magnetic field of 10.5 Oe, whereas the input impedance changed from 12.3 to 10.1 ohm. The parasitic capacitance was driven from the measured reactance and resonance frequency. The inductance and inductive reactance could be evaluated with the parasitic capacitance and measured reactance. The tendency of output voltage dependent on frequency is similar to that of inductive reactance. The sensitivity of the fabricated sensor was 17.6 mV/VOe at 8 MHz. Copyright © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Low-Noise Fully Differential Amplifiers Using JFET-CMOS Integration Technology for Smart SensorsIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2008Hidekuni Takao Member Abstract In this paper, CMOS-based low-noise amplifiers with JFET-CMOS technology for high-resolution sensor interface circuits are presented. A differential difference amplifier (DDA) configuration is employed to realize differential signal amplification with very high input impedance, which is required for the front-end circuit in many sensor applications. Low-noise JFET devices are used as input pair of the input differential stages or source-grounded output load devices, which are dominant in the total noise floor of DDA circuits. A fully differential amplifier circuit with pure CMOS DDA and three types of JFET-CMOS DDAs were fabricated and their noise performances were compared. The results show that the total noise floor of the JFET-CMOS amplifier was much lower compared to that of the pure CMOS configuration. The noise-reduction effect of JFET replacement depends on the circuit configuration. The noise reduction effect by JFET device was maximum of about , 18 dB at 2.5 Hz. JFET-CMOS technology is very effective in improving the signal-to-noise ratio (SNR) of a sensor interface circuit with CMOS-based sensing systems. © 2008 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Small-signal analysis of interleaved dual boost converterINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 6 2001Mummadi Veerachary Abstract This paper presents a systematic development of steady-state, small-signal models of interleaved dual boost converter operating in a continuous current mode. These models are derived by employing the well-known signal flow graph method. This signal flow graph approach provides a means to directly translate the switching converter into its equivalent graphic model, from which a complete behaviour of the converter can easily be studied. Steady-state performance, small-signal characteristic transfer functions are derived using Mason's gain formula. The bode plots of audiosusceptibility, input impedance, output impedance, and control-to-output transfer functions are determined and illustrated using MATLAB for different values of load resistances, duty ratios. Small-signal frequency responses obtained from the signal flow graph method are validated with PSPICE simulator results. To validate the signal flow graph modelling equations, sample steady-state experimental results are provided. Copyright © 2001 John Wiley & Sons, Ltd. [source] A global time domain circuit simulation of a microwave rectennaINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 1-2 2007Brahim Essakhi Abstract The paper presents a global time domain simulation of a microwave rectenna studied for wireless energy transfer. The novelty of the work is to take into account both distributed electromagnetic parts of the antenna and the rectifier circuit including lumped elements. From a 3D finite element time domain electromagnetic modelling of the structure an equivalent circuit of the antenna is deduced: the input impedance is obtained as a function of frequency over a broad band. Then a rational approximation gives a corresponding PSPICE representation. The electromotive force induced between the ports of the antenna during the microwave illumination is directly computed from the 3D transient scattering problem. The resulting equivalent circuit of the antenna is finally incorporated into the electronic simulator PSPICE, together with the lumped components of the rectenna (ideal diodes and load). Thus a global non-linear time domain analysis of the whole structure becomes available. The results obtained with the methods presented in the paper are compared with those resulting from other techniques. The approach developed in the work could efficiently improve the design stage of rectennas devoted to microwave power transfer. Copyright © 2006 John Wiley & Sons, Ltd. [source] The computation of the input impedance of a biconical antenna by means of a method of segmentation based on 3D finite elementsINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2003José Ma Gil Abstract The analysis of structures with complex geometries leads to the use of three-dimensional numerical methods. Such devices can be unmanageable unless a segmentation technique is applied. In this work, a hybrid 3D finite-element-mode matching method, based on the generalized admittance matrix (GAM) is applied to the computation of the input impedance of a biconical antenna fed by a cylindrical cavity loaded with resonant slots and matched by a coupling network composed of three multi-ridge circular irises and sections of circular waveguides. The structure is segmented into regions which are analysed separately and, by means of linking the partial matrices calculated, the generalized scattering matrix (GSM) is obtained. In order to validate the method, numerical results and measurements are compared. Copyright © 2003 John Wiley & Sons, Ltd. [source] Sleeve monopole on a circular ground-planeINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 5 2003Zhongxiang Shen Abstract This paper presents a modal-expansion analysis of a sleeve monopole antenna on a finite ground-plane. Two perfectly conducting plates (one above the monopole and the other under the ground-plane) are introduced to confine the modeling region and to facilitate the modal-expansion analysis. The resulting guided-wave structure is then divided into a number of regions and the electromagnetic field components in each region are expanded into the summation of its modal functions. The surface current distribution on the monopole and the antenna's input impedance and radiation pattern are obtained by finding the expansion coefficients through matching the tangential field components across the regional interfaces. Calculated results by the modal-expansion method agree well with measured results for the return loss of a sleeve monopole fed through a circular ground-plane by a coaxial probe. Numerical results for the surface current distribution, input impedance, and radiation pattern of a sleeve monopole on a circular ground plane are presented and discussed. Copyright © 2003 John Wiley & Sons, Ltd. [source] Efficient analysis of wireless communication antennas using an accurate [Z] matrix interpolation techniqueINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 4 2010Yikai Chen Abstract An accurate impedance matrix interpolation technique based on the surface integral equation (SIE) is presented for the analysis of wireless communication antennas over wide frequency bands. The first-order derivative of the impedance matrix at the internal frequency is considered in the cubic polynomial-based interpolation scheme, thus the novel impedance matrix interpolation scheme will provide high accuracy and high efficiency over a frequency band. To demonstrate the efficiency and accuracy of the proposed method, numerical results for planar inverted F antennas (PIFA) and a wideband E-shaped patch antenna are presented. Good agreement among the interpolation results, exact MoM solutions, finite element method (FEM) solutions, and measured data is observed over the bandwidth. Besides, dimensions of the feeding probe are also studied to investigate their effect on the input impedance and radiation patterns. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source] Application of FIR-neural network on finite difference time domain technique to calculate input impedance of microstrip patch antennaINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2010Dhruba C. Panda Abstract Finite impulse response artificial neural network (FIR-ANN) is used for speeding up the FDTD. The FIR-ANN based FDTD (Neuro FDTD) is used to calculate input impedance of coaxial fed stacked microstrip patch antenna. Input impedance obtained by Neuro FDTD and FDTD are compared. It has been observed that Neuro FDTD provides same result with less number of iteration than compared to FDTD. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [source] Computer-aided design of a CPW-fed slot antenna for MM-wave applicationsINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 1 2004S. K. Padhi Abstract This article presents a comprehensive parametric study with experimental characterization of an inductively coupled CPW-fed slot antenna on a GaAs substrate for MMIC applications. The length, width, and feed inset of the antenna are varied and their influences on the input impedance, bandwidth, and gain are investigated. The parametric study reveals that the slot length is the prime factor for determining the resonant frequency, while the width is used for fine-tuning of resonant frequency and gain-bandwidth product. For the fixed slot dimensions, the feed inset tremendously affects both resonant frequency and input match. The manufactured antenna resonates at 22.4 GHz with a 6.1% impedance bandwidth, 2% gain bandwidth, 2.5-dBi boresight gain, and 5-dB front-to-back (F/B) radiation level. The antenna exhibits bidirectional radiation patterns with almost omnidirectional patterns in the E-plane and a wide beamwidth of 84° 3-dB beam width in the H-plane. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14, 4,14, 2004 [source] Edge feeding of circular patch microstrip antennasINTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 2 2001B. S. Rao Abstract Edge feeding of a circular patch antenna by a microstrip line has been achieved by utilizing the circumferential variation of the field which is fixed by loading the patch. However, loading splits the degenerate modes and gives rise to cross-polarization. Three different techniques are presented to analyze the loaded circular patch antenna. Comparison with the measured results for input impedance and radiation patterns shows good agreement. The concept used here is very general and can be applied to the edge feeding of any ring antenna. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 74,85, 2001. [source] Simulation and scale model measurement of a 600-GHz membrane-based twin slot antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 6 2009W. Miao Abstract In this article, the input impedance (i.e., feed point impedance) of a 600-GHz membrane-based twin slot antenna for superconducting hot-electron-bolometer (HEB) mixers is investigated through numerical simulation and scale model measurement. The twin-slot antenna, with an RF choker filter included, was designed with the aid of Microwave Studio CST. A 200-times scale model of the designed twin slot antenna was fabricated to validate the simulated results. For the scale model measurement, de-embedding measurement technique was adopted to extract the input impedance of the twin slot antenna. The measured results are found in good agreement with the simulation. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1452,1455, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24350 [source] Application of a simplified probe feed impedance formula to the design of a dual frequency patch antennaMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 5 2009Q. Lu Abstract A simplified probe feed input impedance for a rectangular patch antenna based on the Green's function is used to design a dual frequency matched antenna. The predicted results at design frequencies of 1.9 and 2.4 GHz are in close agreement with experimental measurements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1161,1164, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24294 [source] A low power low noise amplifier with subthreshold operation in 130 nm CMOS technologyMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 11 2008Ickhyun Song Abstract In this article, a 5.8 GHz ISM-band CMOS low noise amplifier (LNA) operating in a subthreshold region is presented. A conventional source degeneration inductor is eliminated for higher signal gain while providing reasonable input impedance. The LNA is fabricated using 130 nm CMOS technology and measured signal gain, noise figure, and power consumption are 13.4 dB, 5.2 dB, and 980 ,W, respectively, at target frequency. Also the LNA achieves the highest figure of merit among the recently published subthreshold LNAs. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2762,2764, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23788 [source] Input impedance calculation of dipole antenna using FDTD methodMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2008Wenhua Yu Abstract Since the input impedance of half wavelength dipole antenna is well known, therefore, a dipole antenna is frequently used to validate the computational electromagnetic method. Though its structure is relatively simple, it is not a simple problem for the most computational electromagnetic methods. In this article, we investigate the input impedance of half wavelength dipole antenna using the FDTD method. Numerical experiments have demonstrated that the FDTD method can be used to accurately calculate its input impedance using uniform mesh, nonuniform mesh, or subgridding. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2335,2337, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23631 [source] A CMOS opto-electronic single chip using the hybrid scheme for optical receiversMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 9 2008Jian-Ming Huang Abstract An opto-electronic integrated circuit based on the hybrid scheme for an optical receiver front-end is presented in this article. The proposed integrated circuit adopts the CMOS technology as the vehicle to integrate the InP-based waveguide photodetector into the transimpedance amplifier (TIA) circuit. A regulated cascade structure is used to reduce the input impedance of the TIA. Hence, the proposed integrated circuit can achieve a very high bandwidth provided that the parasitic capacitance of the photodetector is up to 1 pF. The 3-dB bandwidth and the transimpedance gain of the proposed circuit are 1 GHz and 64.5 dB,, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2430,2434, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23693 [source] Active integrated antenna for mobile TV signal receptionMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 12 2007Ick-Jae Yoon Abstract This paper proposes a small-sized field-effect transistor (FET) based active integrated antenna (AIA) for terrestrial digital multimedia broadcasting (T-DMB) signal reception, which is one of the mobile TV services allocated to 200 MHz band. The commercially used T-DMB antenna is a 120 mm long monopole, but the size of the proposed one is reduced to 50 mm by the method of active device integration. The active device integrated to the radiator influences not only on the current distribution at the radiator but also the input impedance, results in an antenna size reduction with an enhanced gain. In addition to this, a band-pass filter is designed at the input port of the radiator. This plays a role as a matching circuit between a radiator and an active device as well as provides a band-selection function simultaneously to be free of other high intensity signals existing around the T-DMB band. The antenna effective length related to the same-sized monopole and noise figure are measured to verify the validity of the proposed antenna. The performance of the proposed FET based AIA shows the feasibility of designing absolutely small-sized antenna with active devices integrated compared to an operating frequency band. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2998,3001, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22968 [source] Dielectric resonator antenna: Operation of the magnetodielectric composites Cr0.75Fe1.25O3 (CRFO)/Fe0.5Cu0.75Ti0.75O3 (FCTO)MICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 2 2007H. H. B. Rocha Abstract The probe-feed cylindrical dielectric resonator antennas (DRA) based on a new magnetodielectric composites Cr0.75Fe1.25O3 (CRFO)/Fe0.5Cu0.75Ti0.75O3 (FCTO) are investigated. The experimental and theoretical characteristics of the antenna like return loss, bandwidth, input impedance, and radiation patterns are in good agreement. Numerical validation is done, tacking into account the air gaps between the dielectric resonator and the metallic conductors. Frequency response bandwidth in the range of 6.6,11.8% was obtained for frequency operation around 4 GHz. The CRFO-FCTO present a dielectric constant in the range of 8,13 with loss around 10,3. To summarize, the performance of a cylindrical DRA based in a new matrix CRFO/FCTO was examined. These measurements confirm the potential use of such materials for small DRA. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 409,413, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22160 [source] Experimental Setup to Evaluate the Performance of Percutaneous Pulmonary Valved Stent in Different Outflow Tract MorphologiesARTIFICIAL ORGANS, Issue 1 2009Riccardo Vismara Abstract Percutaneous pulmonary valve implantation is a potential treatment for right ventricular outflow tract (RVOT) dysfunction. However, RVOT implantation site varies among subjects and the success of the procedure depends on RVOT morphology selection. The aim of this study was to use in vitro testing to establish percutaneous valve competency in different previously defined RVOT morphologies. Five simplified RVOT geometries (stenotic, enlarged, straight, convergent, and divergent) were manufactured by silicone dipping. A mock bench was developed to test the percutaneous valve in the five different RVOTs. The bench consists of a volumetric pulsatile pump and of a hydraulic afterload. The pump is made of a piston driven by a low inertia programmable motor. The hydraulic afterload mimics the pulmonary input impedance and its design is based on a three element model of the pulmonary circulation. The mock bench can replicate different physiological and pathological hemodynamic conditions of the pulmonary circulation. The mock bench is here used to test the five RVOTs under physiological-like conditions: stroke volume range 40,70 mL, frequency range 60,80 bpm. The valved stent was implanted into the five different RVOT geometries. Pressures upstream and downstream of the valved stent were monitored. Flow rates were measured with and without the valved stent in the five mock RVOTs, and regurgitant fraction compared between the different valved stent RVOTs. The percutaneous valved stent drastically reduced regurgitant flow if compared with the RVOT without the valve. RVOT geometry did not significantly influence the flow rate curves. Mean regurgitant fractions varied from 5% in the stenotic RVOT to 7.3% in the straight RVOT, highlighting the influence of the RVOT geometry on valve competency. The mock bench presented in this study showed the ability to investigate the influence of RVOT geometry on the competence of valved stent used for percutaneous pulmonary valve treatment. [source] Effects of inductive coupling on parallel MR image reconstructionsMAGNETIC RESONANCE IN MEDICINE, Issue 3 2004Michael A. Ohliger Abstract Theoretical arguments and experimental results are presented that characterize the impact of inductive coupling on the performance of parallel MRI reconstructions. A simple model of MR signal and noise reception suggests that the intrinsic amount of spatial information available from a given coil array is unchanged in the presence of inductive coupling, as long as the sample remains the dominant source of noise for the coupled array. Any loss of distinctness in the measured coil sensitivities is compensated by information stored in the measured noise correlations. Adjustments to the theory are described to account for preamplifier noise contributions. Results are presented from an experimental system in which preamplifier input impedances are systematically adjusted in order to vary the level of coupling between array elements. Parallel image reconstructions using an array with four different levels of coupling and an acceleration factor up to six show average SNR changes of ,7.6% to +7.5%. The modest changes in overall SNR are accompanied by similarly small changes in g-factor. These initial results suggest that moderate amounts of inductive coupling should not have a prohibitive effect on the use of a given coil array for parallel MRI. Magn Reson Med 52:628,639, 2004. © 2004 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||