PCA Assisted DTCWT Denoising for Improved DOA Estimation of Closely Spaced and Coherent Signals

Performance of standard Direction of Arrival (DOA) estimation techniques degraded under real-time signal conditions. The classical algorithms are Multiple Signal Classification (MUSIC), and Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT). There are many signal conditions hamper on its performance, such as closely spaced and coherent signals caused due to the multipath propagations of signals results in a decrease of the signal to noise ratio (SNR) of the received signal. In this paper, a novel DOA estimation technique named CW-PCA MUSIC is proposed using Principal Component Analysis (PCA) to threshold the nearby correlated wavelet coefficients of Dual-Tree Complex Wavelet transform (DTCWT) for denoising the signals before applying to MUSIC algorithm. The proposed technique improves the detection performance under closely spaced, and coherent signals with relatively low SNR conditions. Also, this method requires fewer snapshots, and less antenna array elements compared with standard MUSIC and wavelet-based DOA estimation algorithms

Case Report : Uncommon presentation of pernicious anemia, hypothyroidism, and pericardial effusion

Introduction: Pernicious anemia is not commonly investigated as an etiology for Vitamin B12 deficiency. However, it is associated with other autoimmune disorders and may be linked with H. pylori infections as well as an increased risk of gastric cancers. Case Presentation: The patient was a 42 year old male patient who presented with hemoglobin of 4.5, MCV of 133.3, and pancytopenia. His symptoms at admission were dyspnea and peripheral neuropathy. His past medical history was significant for hypothyroidism and plaque psoriasis. The patient was found to have low serum vitamin B 12 with positive parietal cell antibodies. Echocardiogram revealed a stable pericardial effusion. He was administered one unit of packed red blood cells, parenteral cobalamin, and oral levothyroxine. He clinically improved with conservative management.Conclusion: This case highlights the constellation of signs, symptoms, laboratory findings, and imaging that can be seen with pernicious anemia, and it also discusses management. It is important for the patient to undergo proper workup of the autoimmune conditions associated with pernicious anemia when appropriate

Throughput Maximization of Cognitive Radio Multi Relay Network with Interference Management

In this paper, an Orthogonal Frequency Division Multiplexing (OFDM) based cognitive multi relay network is investigated to maximize the transmission rate of the cognitive radio (CR) with enhanced  fairness among CR users  with interference to the primary users (PUs) being managed below a certain threshold level. In order to improve the transmission rate of the CR, optimization of the subcarrier pairing and power allocation is to be carried out simultaneously. Firstly joint optimization problem is formulated and Composite Genetic and Ordered Subcarrier Pairing (CGOSP) algorithm is proposed to solve the problem. The motivation behind merging genetic and OSP algorithm is to reduce the complexity of Genetic Algorithm (GA). Further, to have a fair allocation of resources among CR users, the Round Robin allocation method is adopted so as to allocate subcarrier pairs to relays efficiently. The degree of fairness of the system is calculated using Jain’s Fairness Index (JFI). Simulation results demonstrate the significant improvement in transmission rate of the CR, low computational complexity and enhanced fairness

Polyethylene glycol (PEG-400) as a medium for novel and efficient synthesis of 2-phenyl-2,3-dihydroquinazolin-4(1H)-one derivatives

A novel, efficient synthesis of 2-phenyl-2, 3-dihydroquinazolin-4(1H)-one derivatives is reported for the first time in PEG-400 by the reaction of various aldehydes, anthranilamide under catalyst-free conditions and the formation of product good to excellent yields. PEG-400 can be recovered and reused without any significant loss of activity

3-(2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-5-yl)-3-hydr­oxy-1-phenyl­indolin-2-one ethanol solvate

In the title compound, C18H16N4O3·C2H5OH, mol­ecules are linked into chains by a series of inter­molecular N—H⋯O, N—H⋯N and O—H⋯O hydrogen bonds which stabilize the crystal structure. The indole and creatinine units make a dihedral angle of 56.45 (4)°. The title compound has two chiral centres. The crystal structure indicates the compound is racemic (RR and SS)

Pattern and distribution of lung parenchymal changes in COVID-19 infection on high resolution computed tomography: a descriptive cross-sectional study

Background: This was a descriptive cross-sectional study conducted in a tertiary care hospital in south India during the peak of the COVID-19 infection pandemic in India between June 2020 to June 2021. HRCT lung parenchymal findings of patients with COVID-19 infection were studied, and the pattern and distribution of various lung parenchymal changes in each lung were described. HRCT lung findings were further correlated with clinical findings and clinical severity, which further helped in the clinical management of patients.Methods: This descriptive cross-sectional study was done at Sagar Hospitals, Tilak Nagar, Jayanagar, Bengaluru on a total of 111 RT-PCR positive COVID-19 patients in the age group 18 to 80. HRCT lung imaging findings were studied from June 2020 to June 2021 during the pandemic. These findings were further correlated with clinical findings and the clinical severity of the patient.Results: This study showed that chest CT findings in COVID-19 infection are variable. Ground glass opacity was the most common lesion observed, followed by Air space opacification and consolidation with an air bronchogram. In some cases, a crazy-paving pattern, subpleural linear bands, subpleural reticulations and fibrotic streaks were observed. A few cases showed traction bronchiectasis due to adjacent lung fibrosis and lung cyst within lesions. The lesion distribution was both bilateral (more common) and unilateral and showed peripheral predominance. There was a positive correlation between the CT severity score and clinical grading and the clinical severity of the patient.Conclusions: HRCT lung findings in COVID-19 patients were described in detail, including predominant lesion, predominant pattern, distribution in detail with reference to each lung segment, laterality, and correlation with clinical severity

(Z)-Methyl 4-({3-[(2,5-dioxoimidazolidin-4-yl­idene)meth­yl]-1H-indol-1-yl}meth­yl)benzoate

In the title compound, C21H17N3O4, pairs of mol­ecules form a planar[maximum deviation 0.0566 (9) Å] centrosymmetric imidazole dimer via two N—H⋯O hydrogen bonds. These dimeric units are linked by further N—H⋯O hydrogen bonds between the ester carbonyl group and the imidazolidine ring, formiing chains parallel to the c-axis direction. In addition, there are π–π stacking inter­actions between the planar imidazole pairs, with an inter­planar spacing of 3.301 (2) Å. There is a double bond with Z geometry connecting the imidazolidine and indole units

3-(2-Amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-5-yl)-5-fluoro-3-hydr­oxy-1-methyl­indolin-2-one methanol hemisolvate

In the title compound, C13H13FN4O3·0.5CH3OH, mol­ecules are packed in the crystal structure by a series of O—H⋯N, N—H⋯O, N—H⋯F and O—H⋯O inter­molecular hydrogen bonds. The indole and creatinine units make a dihedral angle of 60.80 (4)°