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Fixed point theorems for weak contraction in Intuitionistic fuzzy metric space
Ramesh Kumar Vats,Ramesh Kumar Vats 호남수학회 2016 호남수학학술지 Vol.38 No.2
The notion of weak contraction in intuitionistic fuzzy metric space is well known and its study is well entrenched in the literature. This paper introduces the notion of $(\psi,\alpha,\beta)$-weak contraction in intuitionistic fuzzy metric space. In this contrast, we prove certain coincidence point results in partially ordered intuitionistic fuzzy metric spaces for functions which satisfy a certain inequality involving three control functions. In the course of investigation, we found that by imposing some additional conditions on the mappings, coincidence point turns out to be a fixed point. Moreover, we establish a theorem as an application of our results.
Reduction of Blocking Artifact using Edge Information
Ramesh Kumar Lama,Il-Chul Park,Jae-Young Pyun,Goo-Rak Kwon 대한전자공학회 2010 ICEIC:International Conference on Electronics, Inf Vol.1 No.1
A new method of reducing the blocking artifact in low bit rate coded image is presented in this paper. The proposed algorithm operates being based on the edge pixel residing across the block. The strength of deblocking filter is determined according the number of edge pixel in corresponding block. Proposed algorithm removes the blocking artifact in coded image with good subjective and objective result.
Kumar, P. Ramesh,Jung, Young Hwa,Moorthy, Brindha,Kim, Do Kyung The Electrochemical Society 2016 Journal of the Electrochemical Society Vol.163 No.7
<P>Aqueous sodium ion batteries are future low cost and eco-friendly energy storage systems, but aqueous batteries are very much constrained by the electrolyte degradation. In this aspect, we have evaluated effect of salt concentration and electrolyte additives on aqueous sodium ion full cell performance by using NaTi2(PO4)(3) and Na3V2O2X(PO4)(2)F3-2X as anode and cathode materials respectively. Before making full cell, the effect of adding different concentrations of vinylene carbonate (VC), carboxymethyl cellulose (CMC) and agarose (Ag) to aqueous 10 M NaClO4 electrolyte was correlated by using cathode material in half-cell configuration. In full cell, 10 M NaClO4 electrolytes with 2 v% of VC enhances the cycle stability of NaTi2(PO4)(3)-C//Na3V2O2X(PO4)(2)F3-2X-MWCNT systems compared to other electrolytes. (C) 2016 The Electrochemical Society. All rights reserved.</P>
Effects of Cyclometalation on the Panchromatic Ruthenium Sensitizer for DSSC Applications
Ramesh Kumar Chitumalla,장준경 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.10
Ruthenium sensitizers are promising materials for dye sensitized solar cells (DSSCs) and the concept of cyclometalation has been proposed to advance their performance. Density functional theory (DFT) simulations were performed to elucidate the electronic structure, electrochemical, and optical behavior of a cyclometalated ruthenium dye. The cyclometalated sensitizer has superior electrochemical properties (HOMO, LUMO, and bandgap) compared to its non-cyclometalated sensitizer. Upon cyclometalation, a remarkable improvement in the absorption across the UV–Visible and near-infrared regime has been observed. Furthermore, from the electron density contours of frontier molecular orbitals of dye attached TiO2, the charge transfer and sensitizing properties of the cyclometalated complex are superior to the corresponding non-cyclometalated ruthenium sensitizer. The density of states revealed the strong electronic coupling, which facilitates an effective electron injection into the semiconductor.
An Adaptive Interpolation Algorithm using Two Separate Modes
Ramesh Kumar Lama,Goo-Rak Kwon 한국멀티미디어학회 2010 한국멀티미디어학회 국제학술대회 Vol.2010 No.-
This paper presents an adaptive interpolation algorithm for an image resizing based on two separate modes in terms of activity of pixel in an image. First mode corresponds to smooth region and interpolation operation is performed by the conventional nearest neighbor method because this method is more computationally efficient and gives good quality result for pixels having neighboring pixels with pixel intensity in close proximity to each other. Second mode corresponds to complex region. The target pixel is computed based on Newton interpolation method. To preserve the edge details and to reduce the aliasing effect in scaled image, consecutive pixels are separated into two groups. Group with highly relative pixels is selected for effective interpolation. The simulation results show that the proposed algorithm outperforms the conventional methods even though the computational complexity is low.
Real Coded Biogeography-Based Optimization for Environmental Constrained Dynamic Optimal Power Flow
Kumar, A. Ramesh,Premalatha, L. The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.1
The optimization is an important role in wide geographical distribution of electrical power market, finding the optimum solution for the operation and design of power systems has become a necessity with the increasing cost of raw materials, depleting energy resources and the ever growing demand for electrical energy. In this paper, the real coded biogeography based optimization is proposed to minimize the operating cost with optimal setting of equality and inequality constraints of thermal power system. The proposed technique aims to improve the real coded searing ability, unravel the prematurity of solution and enhance the population assortment of the biogeography based optimization algorithm by using adaptive Gaussian mutation. This algorithm is demonstrated on the standard IEEE-30 bus system and the comparative results are made with existing population based methods.
Ramesh, Tejavathu,Panda, Anup Kumar,Kumar, S. Shiva The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3
This paper presents model reference adaptive system speed estimators based on Type-1 and Type-2 fuzzy logic controllers for the speed sensorless direct torque and flux control of an induction motor drive (IMD) using space vector pulse width modulation. A Type-1 fuzzy logic controller (T1FLC) based adaptation mechanism scheme is initially presented to achieve high performance sensorless drive in both transient as well as in steady-state conditions. However, the Type-1 fuzzy sets are certain and cannot work effectively when a higher degree of uncertainties occurs in the system, which can be caused by sudden changes in speed or different load disturbances and, process noise. Therefore, a new Type-2 FLC (T2FLC) - based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties, improve the performance, and is also robust to different load torque and sudden changes in speed conditions. The detailed performance of different adaptation mechanism schemes are performed in a MATLAB/Simulink environment with a speed sensor and sensorless modes of operation when an IMD is operates under different operating conditions, such as no-load, load, and sudden changes in speed. To validate the different control approaches, the system is also implemented on a real-time system, and adequate results are reported for its validation.
Ramesh Kumar,Sachin D. Kore 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.18 No.8
Magnetic pulse crimping is a solid state, high-speed impact crimping technique. In this paper, copper tube was successfully crimped on the steel 1020 rod. Three types of profiles threaded, knurled, and plain profile were created on the steel rod and then a copper tube was crimped on the rod. The influence of surface profiles on the joint strength, surface roughness and microstructure of the joint were analyzed and compared. Compression-shear tests as well as pull-out tests were carried out to compare the strength of the crimped joint. The result of the pull-out tests as well as compression-shear tests revealed that threaded surface profile on the steel rod gives better strength in comparison to the other two profiles. Along the circumference of the Cu-steel composite rod the microstructure images of the joints were taken and analyzed, it was found that there was no gap along the circumference of the sample crimped at 5.3 kJ of discharge energy with plain profile. For surface roughness, the Ra values of the crimped samples at 5.3 kJ were analyzed and it was found that average Ra value of the sample crimped on the threaded base was highest (0.80 μm) among threaded, knurled, and plain base samples.
Cavitation resistance of concrete containing different material properties
Kumar, G.B. Ramesh,Bhardwaj, Arjit,Sharma, Umesh Kumar Techno-Press 2018 Advances in concrete construction Vol.6 No.1
In the present investigation, influence of various material parameters on the cavitation erosion resistance of concrete was investigated on the basis of laboratory experiments. As there is no well-established laboratory test method for evaluating the cavitation resistance of concrete, a test set up called 'cavitation jet' was specially established in the present study in order to simulate the cavitation phenomenon experienced in the hydraulic structures. Various mixtures of concrete were designed by varying the grade of concrete, type and quantity of pozzolana, type of aggregates and cement type to develop good cavitation resistant concrete constructed using marginal aggregates. Three types of aggregates having three different Los Angeles abrasion values (less than 30%, between 30% and 50% and more than 50%) were employed in this study. To evaluate the cavitation resistance a total of 60 cylindrical specimens and 60 companion cubes were tested in the laboratory respectively. The results indicate that cavitation resistance of concrete degrades significantly as the L.A. abrasion value of aggregates goes beyond the 30% value. Incorporation of pozzolanic admixtures was seemed to be beneficial to enhance the cavitation resistance of concrete. Influence of other material parameters on the cavitation resistance of concrete was also noted and important observations have been made in the paper.