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Search Results: 1 - 10 of 4632 matches for " Yuri Agrawal "
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CT Findings in Patients with Esophageal Carcinoma and Its Correlation with Esophagographic Findings  [PDF]
Basudev Agrawal
Open Journal of Radiology (OJRad) , 2018, DOI: 10.4236/ojrad.2018.82013
Abstract: Aim of the Study: Aim of this study is to evaluate the patients of biopsy proven esophageal carcinoma with Contrast CT studies (CECT thorax, abdomen or neck), correlate and compare the CT findings with esophagographic findings in each case and with biopsy findings wherever possible. Materials and Methods: Fifty (50) biopsy proven cases of esophageal carcinoma were taken into study in Radiology Department of Govt. Medical College, Patiala, Punjab after informed consents. All the patients underwent esophagography with barium sulphate as the contrast material and contrast enhanced CT scan of neck and/or thorax and/or abdomen. In all cases, esophagographic study preceded the CT scan. The time gap between the two studies was kept to the minimum to make the studies comparable. Results: The CT findings were found to have significant correlation with the esophagographic findings (p value > 0.05 in each finding) in regard to luminal narrowing, proximal dilatation and hold up of contrast, eccentricity of growth, site involved, length of growth, involvement of pyriform sinuses/valeculla and involvement of GE junction. Conclusions: CT study primarily helps to rule out unresectable or distant metastatic disease. Barium studies cannot provide any information regarding local invasion into mediastinal structures, regional or non-regional lymphadenopathy or metastases to distant organs which are significant for determining the treatment modality. CT has an advantage over esophagography for these information.
Resonance vector mode locking
Stanislav A. Kolpakov,Sergey V. Sergeyev,Yuri Loika,Nikita Tarasov,Vladimir Kalashnikov,Govind P. Agrawal
Physics , 2015,
Abstract: A mode locked fibre laser as a source of ultra-stable pulse train has revolutionised a wide range of fundamental and applied research areas by offering high peak powers, high repetition rates, femtosecond range pulse widths and a narrow linewidth. However, further progress in linewidth narrowing seems to be limited by the complexity of the carrier-envelope phase control. Here for the first time we demonstrate experimentally and theoretically a new mechanism of resonance vector self-mode locking where tuning in-cavity birefringence leads to excitation of the longitudinal modes sidebands accompanied by the resonance phase locking of sidebands with the adjacent longitudinal modes. An additional resonance with acoustic phonons provides the repetition rate tunability and linewidth narrowing down to Hz range that drastically reduces the complexity of the carrier-envelope phase control and so will open the way to advance lasers in the context of applications in metrology, spectroscopy, microwave photonics, astronomy, and telecommunications.
Compression of MR Images Using DWT by Comparing RGB and YCbCr Color Spaces  [PDF]
Agrawal Jayprkash, Ritu Vijay
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.44046
Abstract: This paper consists of a lossy image compression algorithm dedicated to the medical images doing comparison of RGB and YCbCr color space. Several lossy/lossless transform coding techniques are used for medical image compression. Discrete Wavelet Transform (DWT) is one such widely used technique. After a preprocessing step (remove the mean and RGB to YCbCr transformation), the DWT is applied and followed by the bisection method including thresholding, the quantization, dequantization, the Inverse Discrete Wavelet Transform (IDWT), YCbCr to RGB transform of mean recovering. To obtain the best compression ratio (CR), the next step encoding algorithm is used for compressing the input medical image into three matrices and forward to DWT block a corresponding containing the maximum possible of run of zeros at its end. The last step decoding algorithm is used to decompress the image using IDWT that is applied to get three matrices of medical image.
Scalable Trust-Based Secure WSNs  [PDF]
Amar Agrawal, Ruizhong Wei
Journal of Computer and Communications (JCC) , 2014, DOI: 10.4236/jcc.2014.27003
Abstract:

In this paper, we consider the scalable of wireless sensor networks with trust-based security. In our setting, the nodes have limited capability so that heavy computations are not suitable. So public key cryptographic algorithms are not allowed. We focus on the scalability of the network and proposed new testing algorithms and evaluation algorithms to test new nodes added, which give them reasonable values of trust. Based on these algorithms, we proposed new components for trust management system of wireless sensor networks.

Adaptive Lifting Transform for Classification of Hyperspectral Signatures  [PDF]
Rajesh Agrawal, Narendra Bawane
Advances in Remote Sensing (ARS) , 2015, DOI: 10.4236/ars.2015.42012
Abstract: Supervised classification of hyperspectral images is a challenging task because of the higher dimensionality of a pixel signature. The conventional classifiers require large training data set; however, practically limited numbers of labeled pixels are available due to complexity and cost involved in sample collection. It is essential to have a method that can reduce such higher dimensional data into lower dimensional feature space without the loss of useful information. For classification purpose, it will be useful if such a method takes into account the nature of the underlying signal when extracting lower dimensional feature vector. The lifting framework provides the required flexibility. This article proposes the adaptive lifting wavelet transform to extract the lower dimensional feature vectors for the classification of hyperspectral signatures. The proposed adaptive update step allows the decomposition filter to adapt to the input signal so as to retain the desired characteristics of the signal. A three-layer feed forward neural network is used as a supervised classifier to classify the extracted features. The effectiveness of the proposed method is tested on two hyperspectral data sets (HYDICE & ROSIS sensors). The performance of the proposed method is compared with first generation discrete wavelet transform (DWT) based feature extraction method and previous studies that use the same data. The indices used for measuring performance are overall classification accuracy and Kappa value. The experimental results show that the proposed adaptive lifting scheme (ALS) has excellent results with a small size training set.
Prospects of Carbyne Applications in Microelectronics  [PDF]
Yuri Prazdnikov
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.28100
Abstract: We design carbyne transistor which is integrable into the existing silicon technology and can be scaled up in a rather broad range -- starting from that prepared by us (by 0.5-mkm technology) up to the monomolecular one because the key mechanism here is the inter-chain charge transfer.
Superinjection from Oriented Carbyne as the Result of Landau Quantization in Giant Pseudo-Magnetic Field  [PDF]
Yuri Prazdnikov
Journal of Modern Physics (JMP) , 2013, DOI: 10.4236/jmp.2013.47134
Abstract:

The qualitative explanation of the earlier published experimental data was obtained within new energetic model of oriented carbyne. The conductivity spectrum and the superinjection effect feature Landau quantization in a giant pseudomagnetic field. The relativistic dispersion of carriers and non-dissipative character of their motion cause the effect of superinjection where carriers go upwards on an energetic ladder. Raman-spectra and other data point out to the fact that the plane of carriers’ motion is close to the carbyne-insulator interface. Quantum effects and on-surface conductivity allow considering oriented carbyne as an analogue of topological insulator.

Identification of Rotor Unbalance as Inverse Problem of Measurement  [PDF]
Yuri Menshikov
Advances in Pure Mathematics (APM) , 2013, DOI: 10.4236/apm.2013.39A1004
Abstract:

In this paper, the problem of identification of the characteristics of the rotor unbalance on two supports is investigated as the inverse problem of measurement. The vibration of rotor supports in two mutually perpendicular directions used as the initial information. The inverse problem is considered, taking into account the error of the mathematical description of rotor-bearings system. To obtain estimates of real unbalance characteristics, the hypothesis as to the exact solutions is applied. The method of Tikhonov regularization is used to obtain stable results. Test calculations are given to illustrate the proposed approach.

A Simplified Approach to the Problems of Room-Temperature Superconductivity  [PDF]
Yuri Prazdnikov
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.64043
Abstract: An attempt to simplify the approach to the problems of room-temperature superconductors was done. The key factor has been highlighted—a giant spin-orbit interaction as a result of specific geometry of crystal. Considering oriented carbyne as an example, it was shown that maximal value of SOC was attained in low-dimensional systems. A qualitative model of superconductivity in the localized phase with “pseudo-magnetic field” and “Rashba effective field” as parameters was presented. Their correlation was shown via geometry of electric microfields of crystal. Oriented carbyne was presented as localized phase of room-temperature superconductor and the recipe of its transformation to macroscopic superconductivity was given.
Inverse Problem of Astrodynamics  [PDF]
Yuri Menshikov
World Journal of Mechanics (WJM) , 2015, DOI: 10.4236/wjm.2015.512023
Abstract: We consider the problem of determining the center of mass of an unknown gravitational body, using the disturbances in the motion of observed celestial bodies. In this paper an universal approach to obtain the approximate and stable estimate of problem solution is suggested. This approach can be used in other fields of Science. For example, it can be applied for investigation of interactions between fields of forces and elementary particles using known trajectories of elementary particles motions.
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