Defocusing effects in modulation transfer function (MTF) measurement of charge coupled device (CCD) cameras is the main focus of current paper. We introduce measuring Point-spread function (PSF) in order to calculate the MTF and further more we will study the shape of MTF and its cut-off frequency by adjusting the lens focusing in different locations. A collimated white light LED by broadband s...

Digital Pulse–Width Modulation Control in Power Electronic Circuits: Theory and Applications

In this paper we analyse a successive IC scheme for higher modulation in DS/CDMA systems. The performance under Rayleigh fading is analysed for single modulation systems and systems employing either of two different methods, mixed modulation or parallel channels, for handling multiple data rates. We show that the successive IC scheme for higher modulation together with mixed modulation or paral...

Abstract: This work presents a comparison of three different modulation techniques applied to modular multilevel converters (MMCs). The three modulation strategies studied in this paper are the phase-shifted sinusoidal pulse width modulation (PS-SPWM), the space-vector modulation (SVM) and the nearest level modulation (NLM). This paper focuses on analysing the particularities and implementation...

This paper proposes a hybrid carrier based space vector modulation suitable for multiphase multilevel inverters. Multiphase multilevel inverters are controlled by this hybrid modulation to provide multiphase variable voltage and variable frequency supply. The proposed modulation inherits the features of fundamental frequency modulation and carrier based space vector modulation strategies. The m...

In this paper, we analyze the temporal modulation characteristics of speech and noise from a speech/non-speech discrimination point of view. Although previous psychoacoustic studies [3][10] have shown that low temporal modulation components are important for speech intelligibility, there is no reported analysis on modulation components from the point of view of speech/noise discrimination. Our ...