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61.
An electro-optical sensor for microdisplacement measurements based on the triangulation principle has been reported in our earlier publication. The present paper discusses the theory of the error in measurements arising due to the tilt of the object surface and misalignment of illuminating and detecting arms of the system. A method to eliminate the effect of object tilt in measurements is also discussed. 相似文献
62.
In the present communication glass stability (GS) and glass forming ability (GFA) of Ge25−xSe75Sbx (x = 12, 15, and 18) chalcogenide glasses have been calculated in terms of certain thermal parameters, i.e., reduced glass transition temperature (Trg), Hruby number (H), S-parameter (S), and ΔT. The glassy samples have been prepared by quenching of melt technique. For structure characterization, XRD technique has been used. For thermal analysis Differential Scanning Calorimetery (DSC) has been used. DSC scans have been recorded at different heating rates, i.e., 5, 10, 15, and 20 K min−1. Stability of glassy samples has also been confirmed in terms of activation energy of glass transition calculated by Kissinger relation. All these parameters indicate that GS and GFA both decrease with increase of Sb content in Ge25−xSe75Sbx (x = 12, 15, and 18) glassy series. 相似文献
63.
Palafox MA Rastogi VK Tanwar RP Mittal L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2003,59(11):2473-2486
Vibrational study of the biomolecule 2-thiouracil was carried out. Ab initio and density functional calculations were performed to assign the experimental spectra. A comparison with the uracil molecule was made, and specific scale factors were deduced and employed in the predicted frequencies of 2-thiouracil. Several scaling procedures were used. The geometry structure of the molecule was determined. The effect of sulfur substitution at C2 position in the uracil molecule, on the N1-H and N3-H frequencies and intensities reflects changes in proton donor abilities of these groups. Calculations with the 6-31 G** basis set with HF and DFT methods appear in general to be useful for interpretation of the general features of the IR and Raman spectra of the molecule. Using specific scale factors a very small error was obtained. The use of these specific scale factors resolve and correct some of the controversial assignments in the literature. 相似文献
64.
Zeena S. Pillai P. K. Sudeep K. George Thomas 《Research on Chemical Intermediates》2003,29(3):293-305
Photophysical properties of hemicyanine dyes (1 - 3) were investigated in solvents of varying polarity and viscosity. Hemicyanines possess relatively low fluorescence quantum yields (1%) in polar solvents. A significant increase in fluorescence quantum yield and lifetimes was observed with increase in viscosity of the solvent medium. The radiative, as well as nonradiative decay channels from the singlet-excited state were investigated by varying the viscosity of the medium. The viscosity-dependent radiationless relaxation observed in hemicyanine dyes is suggestive of a restricted rotor motion in the singlet excited state. 相似文献
65.
Mst Nasima Khatun Arvin Sain Tanwar Niranjan Meher Parameswar Krishnan Iyer 《化学:亚洲杂志》2019,14(24):4725-4731
The development of a new naphthalene appended naphthalimide derivative ( NMI ) with aggregation‐induced enhanced emission (AIEE) property for the sensitive detection of 4‐nitroaniline (4‐NA) in aqueous media is presented here. The newly designed naphthalimide AIEEgen has an exceptional blue‐shifted condensed state emission that is devoid of any receptor site, accomplished ultrasensitive detection of 4‐NA, which is one of the broad‐spectrum pesticides that belong to the class III toxic chemical, at parts per billion level (LOD/36 ppb, Ksv=4.1×104 m ?1) in water with excellent selectivity even in the presence of potentially competing aliphatic and aromatic amines. The reported probe is the first of its kind, demonstrating major advantages of receptor‐free inner filter effect (IFE) mechanism for the sensitive detection of 4‐NA using an AIEEgenic probe. Excellent sensitivity for 4‐NA is also achieved on paper‐based test‐strip for low‐cost on‐site detection. 相似文献
66.
Sudeep Tanwar Shriya Kaneriya Neeraj Kumar Sherali Zeadally 《International Journal of Communication Systems》2020,33(15)
Smart grid systems are widely used across the world for providing demand response management between users and service providers. In most of the energy distributions scenarios, the traditional grid systems use the centralized architecture, which results in large transmission losses and high overheads during power generation. Moreover, owing to the presence of intruders or attackers, there may be a mismatch between demand and supply between utility centers (suppliers) and end users. Thus, there is a need for an automated energy exchange to provide secure and reliable energy trading between users and suppliers. We found, from the existing literature, that blockchain can be an effective solution to handle the aforementioned issues. Motivated by these facts, we propose a blockchain‐based smart energy trading scheme, ElectroBlocks, which provides efficient mechanisms for secure energy exchanges between users and service providers. In ElectroBlocks, nodes in the network validate the transaction using two algorithms that are cost aware and store aware. The cost‐aware algorithm locates the nearest node that can supply the energy, whereas the store‐aware algorithm ensures that the energy requests go to the node with the lowest storage space. We evaluated the performance of the ElectroBlocks using performance metrics such as mining delay, network exchanges, and storage energy. The simulation results obtained demonstrate that ElectroBlocks maintains a secure trade‐off between users and service providers when using the proposed cost‐aware and store‐aware algorithms. 相似文献
67.
Sudhanshu Tyagi Sudeep Tanwar Sumit Kumar Gupta Neeraj Kumar Joel J.P.C.Rodrigues 《中兴通讯技术(英文版)》2014,(3):22-29
Over the past few decades, there has been a revolution in ICT, and this has led to the evolution of wireless sensor networks(WSN), in particular, wireless body area networks. Such networks comprise a specialized collection of sensor nodes(SNs) that may be deployed randomly in a body area network to collect data from the human body. In a health monitoring system, it may be essential to maintain constant environmental conditions within a specific area in the hospital. In this paper, we propose a temperature-monitoring system and describe a case study of a health-monitoring system for patents critically ill with the same disease and in the same environment. We propose Enhanced LEACH Selective Cluster(E-LEACH-SC) routing protocol for monitoring the temperature of an area in a hospital. We modified existing Selective Cluster LEACH protocol by using a fixed-distance-based threshold to divide the coverage region in two subregions. Direct data transmission and selective cluster-based data transmission approaches were used to provide short-range and long-distance coverage for the collection of data from the body of ill patients. Extensive simulations were run by varying the ratio of node densities of the two subregions in the health-monitoring system. Last Node Alive(LNA), which is a measure of network lifespan, was the parameter for evaluating the performance of the proposed scheme. The simulation results show that the proposed scheme significantly increases network lifespan compared with traditional LEACH and LEACH-SC protocols, which by themselves improve the overall performance of the health-monitoring system. 相似文献
68.
Rajesh Gupta Sudeep Tanwar Sudhanshu Tyagi Neeraj Kumar 《International Journal of Communication Systems》2019,32(14)
Over the last few years, communication latency has been a major hurdle for most of the applications deployed in different network domains. During this era, a number of communication protocols and standards were developed and used by the community. However, still, the problem of latency persists keeping in view of the quality of service (QoS) and quality of experience (QoE) for different applications. To mitigate the aforementioned issues, in this paper, we present an in‐depth survey of state‐of‐the art proposals having tactile internet as a backbone for delay mitigation using 5G networks for future ultra‐reliable low‐latency applications such as Healthcare 4.0, Industry 4.0, virtual reality and augmented reality, and smart education. From the existing proposals, it has been observed that tactile internet can provide interactions between virtual objects to give a feel of real environment with maximum latency of 1 millisecond. Also, this paper highlights the key differences between the tactile internet and Internet of Things in context with 5G revolution. Then open issues and challenges of tactile internet for smart applications are analyzed. Finally, a comparison of existing proposals with respect to various parameters is presented, which allows the end users to select one of the proposals in comparison with its merits over the others. 相似文献
69.
Aditya Bakshi Sunanda Gupta Akhil Gupta Sudeep Tanwar Kuei‐Fang Hsiao 《International Journal of Communication Systems》2020,33(12)
In recent years, to solve the problem of face spoofing, momentous work has been done in this field, but still, there is a need for establishing counter measures to the biometric spoofing attacks. Although trained and evaluated on different databases, impressive results have been achieved in existing face anti‐spoofing techniques, but biometric authentication is a very significant problem as imposters are using lots of reconstructed samples or fake synthetic material or structure that can be used for various attack purposes. For the first time, to the best of our knowledge, this paper explains the security for face anti‐spoofing detection using linear discriminant analysis and validates the results by calculating HTER and accuracy on different databases (i.e., REPLAY ATTACK and CASIA). The proposed model, that is, three‐tier face anti‐spoofing detection model (3T‐FASDM), is used for the detection of the fake biometric user and works well for real‐time applications. The proposed methods tested on a set of state‐of‐the‐art anti‐spoofing features for the face mode gives a very low degree of complexity as 26 general image quality measures are applied to differentiate among legitimate and imposter samples. The outcomes obtained from publically available data show that this technique has improved performance and accuracy by analyzing the HTER and machine learning classifiers that are helpful to differentiate among real and fake traits. 相似文献
70.
P. V. Sudeep P. Palanisamy Chandrasekharan Kesavadas Jan Sijbers Arnold J. den Dekker Jeny Rajan 《Signal, Image and Video Processing》2017,11(5):913-920
A phase map can be obtained from the real and imaginary components of a complex valued magnetic resonance (MR) image. Many applications, such as MR phase velocity mapping and susceptibility mapping, make use of the information contained in the MR phase maps. Unfortunately, noise in the complex MR signal affects the measurement of parameters related to phase (e.g, the phase velocity). In this paper, we propose a nonlocal maximum likelihood (NLML) estimation method for enhancing phase maps. The proposed method estimates the true underlying phase map from a noisy MR phase map. Experiments on both simulated and real data sets indicate that the proposed NLML method has a better performance in terms of qualitative and quantitative evaluations when compared to state-of-the-art methods. 相似文献