251 research outputs found
A Novel Fuzzy Logic Based Adaptive Supertwisting Sliding Mode Control Algorithm for Dynamic Uncertain Systems
This paper presents a novel fuzzy logic based Adaptive Super-twisting Sliding
Mode Controller for the control of dynamic uncertain systems. The proposed
controller combines the advantages of Second order Sliding Mode Control, Fuzzy
Logic Control and Adaptive Control. The reaching conditions, stability and
robustness of the system with the proposed controller are guaranteed. In
addition, the proposed controller is well suited for simple design and
implementation. The effectiveness of the proposed controller over the first
order Sliding Mode Fuzzy Logic controller is illustrated by Matlab based
simulations performed on a DC-DC Buck converter. Based on this comparison, the
proposed controller is shown to obtain the desired transient response without
causing chattering and error under steady-state conditions. The proposed
controller is able to give robust performance in terms of rejection to input
voltage variations and load variations.Comment: 14 page
THROTTLE-BY-WIRE (TBW) FOR RETROFIT CONVERSION OF HYBRID ELECTRIC VEHICLE (HEV) USING NI COMPACT RIO & LABVIEW
Conventional throttle body in a vehicle is controlled mechanically via cable and this project propose a method for replacing the conventional throttle body with an electronic throttle body (ETB) and fine-tune the system in order to implement electronic throttle-by-wire (TBW) for retrofit conversion of hybrid electric vehicle (HEV) to enable diligent control of throttle valve by using National Instrument’s compact Reconfigurable Input Output (cRIO) hardware and Laboratory Instrumentation Engineering Workbench (LabVIEW) graphical user interface (GUI)
A Density Functional Theory Study of Raman Modes of Hydrogenated Cadmium Sulphide Nanoparticles
Raman scattering investigations based on density functional theory (DFT) calculations were performed to explore the vibrational modes of wurtzite structured CdS nanoparticles (NPs). The calculations were performed to obtain the Raman spectra for the CdS containing 2, 4, 8 and 12 atoms to study the size dependence. Several vibrational modes indicating stretching and bending features related to Cd and S atoms were observed. Modifications of the frequency and intensity of different Raman modes with an increase in number of atoms in NPs are discussed in detail. It is found that the frequency of the CdS symmetric stretching mode of vibration shows a consistent red shift and that of CdS anti‐symmetric stretching shows a consistent blue shift with the increase in the number of atoms. Hydrogen atoms were added in order to make the closed shell configuration and saturate the NPs as per the requisite for calculating the Raman spectra. This produced some additional modes of vibration related to hydrogen atoms. The SH stretching mode showed a consistent red shift and the CdH stretching mode showed a consistent blue shift with an increase in the number of atoms in NPs. The results generated are found to be in close agreement with the literature. The observed red shift in different modes is assigned to stimulated Raman stretching and blue shift is ascribed to the coherent anti‐stokes Raman scattering
Wireless Cellular Technologies and Convergence
Mobile communication technologies have gone through with several innovative improvements by developing various multiple-access procedures like TDMA, FDMA, CDMA, WCDMA, EDGE etc., which are used for wireless communication. But a big challenge is to select the right technology for the applications. Common wireless technologies are using radio waves. With radio waves distances can be short, such as a few meters for television or thousands or even millions of kilometres for deep-space radio communications. Wireless communications also use other electromagnetic wireless technologies, such as light, magnetic or electric fields or sound. Mobile wireless technologies have experienced 4 or 5 generations of technology revolution and evolution in the past few decades, namely from 1G to 4G. Current research in mobile wireless technologies concentrates on high level implementation of 4G technology and 5G technology. The architecture of future 5G systems, their performance, and mobile services are requiring to be clearly define. Expectations we can set for 5G technology are, the convergence of maximum of current mobile communication networks with other complementary radio access technologies. As a result, 5G technology will not be a single radio access interface but rather a ??network of networks??
Study of Types and Practice of Network Convergence
What we understand, Network convergence as the provision of telephone, video and data communication services within a single network. In different words, one company provides services for all forms of communication through a single media. Network convergence is the outcome of development of technology and need and the practices it follows
Cognitive Radio : A Solution for Issues in Network Convergence
While planning for strategic communication no nation or organisation can ignore the problems of dynamic radio resource allocation and interference. Among lot number of technologies as a solution Cognitive Radio (CR) is the best one, which helps to overcome the problem of interference, and also allow efficient and dynamic radio resource allocation. Applying Cognitive Radio Networks (CRN) to strategic communications as a solution, this roadmap has been proposed by nations and organizations. For fast network deployment it is mandatory to overcome traffic problem in spectrum, increase communication reshaping mechanism and also strategic radio should act as multi-functional Radio-Frequency(RF) Unit, these are the themes for which CRN is the choice. Wireless Sensor Networks(WSNs) present day have many challenges, if it get clubbed with CR, many problems can be solved. Theme of our research is to empower CRN, so that it will help to solve above problems and also help to manage traffic in network convergence services without ignoring or compromising security
Physiological studies on the effects of nutritional imbalance on the central nervous system: hormone-like action of the blood of thiamine-deficient chicken, Gallus domesticus
When applied in situ to the beating heart of normal chickens, blood from thiamine [59-43-8]-deficient chickens decreased the burst frequency, burst amplitude, and burst duration and increased the interburst interval
Diffraction Investigations of High Temperature Shape Memory Alloys
Shape memory alloys are intermetallic materials with a unique ability to revert to a predefined physical shape by virtue of diffusionless transformations. Recent interest by aerospace and
automotive industries to exploit the functionalities of these materials in future energy efficient designs has renewed scientific research in this field. However, the current understanding of
transformation hysteresis is inhibited by experimental difficulties associated with viewing the
transformations and therefore most of our knowledge is confined to symptomatic bulk properties
such as those accessible from calorimetry and dilatometry.
In the current study, in situ synchrotron X-ray diffraction (SXRD) was used to accurately
document the adaptability of unit cells of participating phases during transformation in a series
of high temperature shape memory alloys (HTSMAs). Selected alloys based on NiTi, ZrCu
and NiMnGa systems were prepared in vacuum arc melter, homogenized and rolled to grain
size adequate for SXRD experiments. The resulting diffraction patterns were Rietveld refined and the evolution of unit cell parameters of participating phases were recorded as a function of
temperature.
It was observed that the lattices of participating phases undergo a significant overall dilation
during transformation. The lower symmetry martensite unit cell was observed to undergo unprecedented
anisotropic strains, reaching as high as 1.2% in certain alloys. The high temperature
higher symmetry austenite was observed to complement the changes in martensite lattice during
heating and vice versa was observed during cooling. These changes were mostly observed in final stages of transformation. Surprisingly, a negative coefficient of thermal expansion was observed
in the b lattice parameter of the monoclinic martensite in NiTi based alloys. The implications
of such strains on the current phenomenological martensitic transformation models that takes
into consideration lattice parameters away from the transformation regime for prediction of
orientation between participating phases has been discussed
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