DISCRIMINATING HUMAN WHISPERS FROM PEST SOUND DURING RECORDINGS IN COCONUT PALM GROOVES USING MFCC AND VECTOR QUANTIZATION

Abstract The key pest of horticultural and ornamental palm species in Asia are endangering landscape. The pest specially the Red Palm Weevil bores deep into palm crowns ,trunks and offshoots and remains hidden from visual inspection until the palms are nearly dead. Acoustic signals of this boring pest can be recorded from the infested palms using the off-the-shelf recording devices. Whispers from human during recording may result in wrong interpretations confirming the presence of some acoustic activity of the pest. This can be differentiated by using MFCC and VQ. The MFCC is applied on input for sound identification and VQ a quantization method deals with vectors. This paper illustrates how human whispers can be differentiated from pest's acoustic activity during recording

Design of a Low Voltage RF MEMS Capacitive Switch with Low Spring Constant

ABSTRACT: This paper reports on the design, testing of a low-actuation voltage Microelectromechanical systems (MEMS) switch for high-frequency applications. In the case of micromachined antennas, which involve low voltage signals, RF MEMS switches with low actuation voltage are required. The actuation voltage of RF MEMS switches mainly depends on the spring constant of the switch membrane. The mechanical design of low spring-constant foldedsuspension beams is presented first, and switches using these beams are demonstrated with measured low actuation voltage. KEYWORDS: Capacitive switch, Low actuation voltage, RF MEMS, Spring constant. I.INTRODUCTION MICROMACHINING and microelectromechanical systems (MEMS) are among the most promising enabling technologies for developing low-power low-cost miniaturized RF components for high-frequency applications. Applications such as cognitive radio system, Multiple-input multiple-output (MIMO) channels and satellite communication need antenna with the reconfigurable parameters The lifetime of capacitive switches strongly depends on the applied actuation voltage for capacitance switches, they experimentally observed a lifetime improvement of a decade for every 5-7-V drop on the switch pull-in voltage In this paper, an RF MEMS capacitive switch with low spring constant operating at a low actuation voltage is presented. II.RF MEMS SWITCHES RF MEMS switches can be classified as capacitive or ohmic on the basis of circuit configuration and as series or shunt based on the nature of contact. The ohmic contact switch consists of a thin metallic strip fixed at one end, suspended over the metallic transmission line with a gap of few microns. A metallic electrode is attached between the transmissio

Frequency splitting elimination and cross-coupling rejection of wireless power transfer to multiple dynamic receivers

Simultaneous power transfer to multiple receiver (Rx) system is one of the key advantages of wireless power transfer (WPT) system using magnetic resonance. However, determining the optimal condition to uniformly transfer the power to a selected Rx at high efficiency is the challenging task under the dynamic environment. The cross-coupling and frequency splitting are the dominant issues present in the multiple Rx dynamic WPT system. The existing analysis is performed by considering any one issue present in the system; on the other hand, the cross coupling and frequency splitting issues are interrelated in dynamic Rx’s, which requires a comprehensive design strategy by considering both the problems. This paper proposes an optimal design of multiple Rx WPT system, which can eliminate cross coupling, frequency splitting issues and increase the power transfer efficiency (PTE) of selected Rx. The cross-coupling rejection, uniform power transfer is performed by adding an additional relay coil and independent resonance frequency tuning with capacitive compensation to each Rx unit. The frequency splitting phenomena are eliminated using non-identical transmitter (Tx) and Rx coil structure which can maintain the coupling between the coil under the critical coupling limit. The mathematical analysis of the compensation capacitance calculation and optimal Tx coil size identification is performed for the four Rx WPT system. Finite element analysis and experimental investigation are carried out for the proposed design in static and dynamic conditions

Frequency Splitting Elimination and Cross Coupling Rejection of Wireless Power Transfer to Multiple Dynamic Receivers

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A computational study of a chemical gas sensor utilizing Pd–rGO composite on SnO2 thin film for the detection of NOx

Abstract In this paper we discussed, nitrogen oxides gas sensors are designed and simulated using the MEMS-based tool of COMSOL Multiphysics software. Pd–rGO composite films were designed and their NOx sensing characteristics were investigated in this study by comparing with/without active layers. Transition metal SnO2 deals with four different active materials i.e., Pure SnO2, SnO2–Pd, SnO2–rGO, and SnO2–Pd/rGO film was controlled by altering the active materials during the active layer deposition. The deposition of Pd/rGO active material is integrated into the SnO2 thin film. The response of the nanocomposite materials on the NOx gas sensor at a low temperature below 100 °C was significantly improved. Moreover, we investigate the optimization from different active layer response for NOx by applying power in watt and milliwatt to the interdigitated electrode on the Sn substrate. The determination is tense to finalize the suitable materials that to detect more response for nitrogen oxides i.e., Pd/rGO layer shows better performance when compared with other active layers for the sensing of nitrogen oxides is in proportion to the power in the range of 0.6–4.8 W at (1–8) Voltage range. This advanced research will enable a new class of portable NOx gas sensors to be constructed with millimeter size and microwatt power