Indian Institute of Technology Indore

About: Indian Institute of Technology Indore is a education organization based out in Indore, Madhya Pradesh, India. It is known for research contribution in the topics: Fading & Support vector machine. The organization has 1606 authors who have published 4803 publications receiving 66500 citations.

Joint Time-Frequency Domain-Based CAD Disease Sensing System Using ECG Signals

Abstract: In this paper, the time-frequency matrix-based modified features are proposed. The proposed features are applied to detect the presence of coronary artery disease (CAD) using electrocardiogram (ECG) signals. These features are utilized to detect the presence of CAD using ECG signals. In the proposed work, ECG beats are subjected to the improved eigenvalue decomposition of Hankel matrix and Hilbert transform (IEVDHM-HT)-based method. This approach provides the time-frequency representation (TFR) of the ECG beats of both classes. Further, the time-frequency-based parameters are computed from the TFR matrix. These parameters are mixed averages time-frequency ( ${\mathrm {Avg}}_{tw}$ ), frequency average ( ${\mathrm {Avg}}_{w}$ ), and time average ( ${\mathrm {Avg}}_{t}$ ) of joint time-frequency distribution functions. In this paper, these features are extracted from the complete TFR and also for the local regions of the same TFR. These features are fed to the random tree and J48 classifiers. The proposed method has obtained an accuracy of 99.93% in the separation of CAD and normal ECG beats. The ${\mathrm {Avg}}_{w}$ features are found to be more effective as compared to the other features.

β-Substituted ferrocenyl porphyrins: synthesis, structure, and properties

Abstract: β-Substituted ferrocenyl porphyrins were designed and synthesized by the Pd-catalyzed Sonogashira cross-coupling reaction. The UV-vis absorption, emission, and cyclic voltammetric results indicate strong electronic communication between ferrocene and porphyrin. The porphyrin 4a is non-emissive in nature, while 4b and 4c show reduced fluorescence quantum yield. The single crystal X-ray structure of 4b is reported, which shows extensive C–H–π interactions.

Mechanochromism and Aggregation-Induced Emission in Phenanthroimidazole Derivatives: Role of Positional Change of Different Donors in a Multichromophoric Assembly.

Abstract: Organic materials possessing solid-state emission responsive to external stimuli have significance in a variety of material, biomedical, and optoelectronic applications. Organic molecules having different donor-acceptor architectures integrated with aggregation-induced emission (AIE) fluorophores have been utilized in development of mechanofluorochromic (MFC) materials. In this work, we have designed and synthesized phenanthroimidazole (PI) based derivatives TPE-PI-1, TPE-PI-2, TPE-PI-3, PTZ-PI-1, PTZ-PI-2, and PTZ-PI-3 where in donors tetraphenylethylene-TPE (D) and phenothiazine-PTZ (D') of contrasting donor abilities are attached to the N and C atom positions of PI. The position and mode of attachment of the donors have been changed, and an additional PTZ spacer has been introduced which has a direct consequence on their photophysical and electronic properties. The PI derivatives manifest AIE, solvatochromic, and mechanochromic behavior. The single crystal X-ray analysis of TPE-PI-1 and PTZ-PI-2 reveals bent structures for the PTZ unit and a twisted conformation for TPE moieties. The density functional theory calculations were used to obtain optimized ground-state structures of the PI derivatives. The work shows a comprehensive comparison of the photophysical, electronic, AIE, and MFC properties of the PI derivatives as an effect of variations in the position of donor, donor-acceptor strength, and change in molecular conformation on use of spacer.

Adaptive Sparse Dictionary-Based Kernel Minimum Symbol Error Rate Post-Distortion for Nonlinear LEDs in Visible Light Communications

Abstract: Visible light communications (VLC) has emerged as one of the prominent technologies to cater to the ever-increasing high-speed-data demand for proposed fifth-generation (5G) systems. However, two main issues affect the performance of VLC in an indoor environment: a) nonlinearity of light-emitting diode, which renders the overall system nonlinear; and b) intersymbol interference due to the propagation channel, which closes the eye diagram of the transmit constellation and, hence, causes it to be unsuitable for detection. To counter these artifacts, complex post-distortion receivers such as the Volterra-decision feedback equalizer (DFE) have been proposed to recover the transmit symbols. In this paper, the use of a reproducing kernel Hilbert space-based minimum symbol error rate equalizer is proposed that provides performance comparable to a long Volterra-DFE, with much less computational cost. Simulations have been carried over IEEE 802.15 personal area network (PAN) channels, which suggest that the proposed approach gives equivalent performance in an indoor VLC channel, as compared with Volterra-DFE with far fewer computations. An analytical expression for mean square error dynamics over these channels is also derived, and it is observed that the theoretically derived expression matches the simulation results for the considered IEEE 802.15 PAN indoor VLC channels.