A voltage source inverter is commonly used to supply a three-phase induction motor with variable frequency and variable voltage for variable speed applications. A suitable pulse width modulation (PWM) technique is employed to obtain the required output voltage in the line side of the inverter. The different methods for PWM generation can be broadly classified into Triangle comparison based PWM ...

(ABSTRACT) As traditional control schemes, open-loop Hysteresis and closed-loop pulse-width-modulation (PWM) have been used for the switched reluctance motor (SRM) current controller. The Hysteresis controller induces large unpleasant audible noises because it needs to vary the switching frequency to maintain constant Hysteresis current band. In contract, the PWM controller is very quiet but di...

The neoplastic T cells of a series of seven patients with chronic T-cell neoplasia were tested for helper activity on pokeweed mitogen (PWM)-induced and interleukin 2 (IL-2)-induced Ig synthesis. The neoplastic T cells of all patients had a T3+4+8-11+I1- phenotype but differed in expression of the 3A1 antigen. The neoplastic T cells of three patients had helper activity on both PWM- and IL-2-dr...

BACKGROUND AND PURPOSE Our purpose was to compare diffusion tensor MR and magnetization transfer imaging in assessing normal-appearing white matter (WM) regions in multiple sclerosis (MS). METHODS Diffusion tensor, magnetization transfer, and conventional MR imaging were performed in 12 patients with MS. Fractional anisotropy, apparent diffusion coefficients (ADCs), and magnetization transfer...

This paper presents the comparison of various Pulse Width Modulation (PWM) strategies for the three phase Diode Clamped Multi Level Inverter (DCMLI). The main contribution of this paper is the proposal of new modulation schemes with Variable Amplitude (VA) and various new schemes adopting the constant switching frequency and also variable switching frequency multicarrier control freedom degree ...

The determination of the frequency spectrum of a pulse width modulated (PWM) signal with general band-limited input x(t) has been an open problem for many years. We describe a new approach that gives exact analytical expressions for the spectra of uniform-sampling PWM signals and natural-sampling PWM signals with single-edge as well as with doubleedge modulation. For the special case of single ...

The majority of lymphoid cells from a patient with non-Hodgkin's lymphoma with leukemic transformation were demonstrated to carry receptors for both sheep erythrocytes and complements by the combined rosette assay using neuraminidase-treated sheep erythrocytes and complement-coated zymosan beads. Most of them were considered morphologically lymphoblasts and were positive for acid phosphatase st...

T cells were derived from the bone marrow of 8 healthy donors and fractionated, according to their receptors for the Fc fragment of IgG, into TG+ and TG- lymphocytes. These were then cocultured with autologous or allogeneic bone marrow cells in agar in the CFU-C assay. No significant suppresion of colony formation could be detected. Total T, TG+, and TG- cells were then incubated for 18 hr with...