Revisiting Nuclear Quadrupole Moments in 39−41^{39-41}K Isotopes

Nuclear quadrupole moments ($Q$s) in three isotopes of potassium (K) with atomic mass numbers 39, 40 and 41 are evaluated more precisely in this work. The $Q$ value of $^{39}$K is determined to be 0.0614(6) $b$ by combining the available experimental result of the electric quadrupole hyperfine structure constant ($B$) with our calculated $B/Q$ result of its $4P_{3/2}$ state. Furthermore combining this $Q$ value with the measured ratios $Q$($^{40}$K)$/Q$($^{39}$K) and $Q$($^{41}$K)$/Q$($^{39}$K), we obtain $Q$($^{40}$K)$=-0.0764(10) \ b$ and $Q$($^{41}$K)$=0.0747(10) \ b$, respectively. These results disagree with the recently quoted standard values in the nuclear data table within the given uncertainties. The calculations are carried out by employing the relativistic coupled-cluster theory at the singles, doubles and involving important valence triples approximation. The accuracies of the calculated $B/Q$ results can be viewed on the basis of comparison between our calculated magnetic dipole hyperfine structure constants ($A$s) with their corresponding measurements for many low-lying states. Both $A$ and $B$ results in few more excited states are presented for the first time.Comment: 9 pages, 1 figur

Correlation trends in the ground state static electric dipole polarizabilities of closed-shell atoms and ions

We employ the closed-shell perturbed relativistic coupled-cluster (RCC) theory developed by us earlier [Phys. Rev. A {\bf 77}, 062516 (2008)] to evaluate the ground state static electric dipole polarizabilities (\alpha s) of several atomic systems. In this work, we have incorporated a class of higher order many-body effects in our calculations that had not been taken into account in the above paper. We highlight their importance in improving the accuracy of $\alpha$. We also calculate the ground state \alpha s of the inert gas atoms and several iso-electronic singly and doubly charged ions in order to make a comparative study of the trends of the correlation effects. Furthermore, we have developed a method to construct intermediate diagrams that are required for the computation of the unperturbed singles and doubles coupled-cluster amplitudes. Our RCC results are compared with those of many-body perturbation theory at different orders to demonstrate the importance of higher order correlation effects for the accurate determination of (\alpha s) of the systems that we have considered.Comment: 11 pages, 15 figure

Transition properties of potassium atom

We report here oscillator strengths, transition rates, branching ratios and lifetimes due to allowed transitions in potassium (K) atom. We evaluate electric dipole (E1) amplitudes using an all order relativistic many-body perturbation method. The obtained results are compared with previously available experimental and theoretical studies. Using the E1 matrix elements mentioned above and estimated from the lifetimes of the 4P states, we determine precise values of static and dynamic polarizabilities for the first five low-lying states in the considered atom. The static polarizabilities of the ground and 4P states in the present work are more precise than the available measurements in these states. Only the present work employs relativistic theory to evaluate polarizabilities in the 3D states for which no experimental results are known to compare with. We also reexamine "magic wavelengths" for the $4P_{1/2} \rightarrow 4S$ and $4P_{3/2} \rightarrow 4S$ transitions due to the linearly polarized light which are useful to perform state-insensitive trapping of K atoms.Comment: 12 pages, 2 figure

A Novel Deep Learning Approach for Diagnosing Sleep Apnea Using Feature Fusion of ECG and SpO2 Signals

Introduction: Frequent disruptions in breathing during sleep also known as Sleep Apnea (SA), is a common sleep disorder, that poses serious health concerns all across the world. Global prevalence of SA is very high, around 936 million adults are suffering from this disorder worldwide. Primary causes of SA include Obesity, old age, being male, high BMI and some other causes are smoking, alcohol, opium consumption etc. If untreated on time, has severe consequences like morning head ache, daytime sleepiness, fatigue, hypertension, diabetes, cognitive impairments and in some cases, it extends to cardiovascular diseases, stokes as well.Objectives: The aim of this research-study is to identify sleep apnea events through the analysis of Electrocardiogram (ECG / EKG), Blood Oxygen saturation level (SpO2) signals. Methods: The study employs the PhysioNet Apnea ECG 1.0.0 dataset for training a machine learning/deep learning algorithm. The proposed system processes ECG and SpO2 data concurrently, with machine learning models trained individually for each type of signal. ECG signals offer crucial insights into heart rate variability and arrhythmias, while SpO2 measurements reveal variations in blood oxygenation during sleep. Training models on these individual signals allows for the capture of unique properties significant to sleep apnea identification. A new feature space is formed by concatenating the features extracted from both these signals and then a 1D-CNN model was trained-tested on this new feature set, enhancing the overall accuracy of predictions. Using ECG and SpO2 data, this model accurately identifies apnea occurrences. Results: The technique yielded promising results, potentially enhancing the early-stage diagnosis and treatment recommendation for sleep-apnea. Our research analysis attained Accuracy, Specificity and AUC of 91%, 92% and 0.93 respectively. Conclusions: Using multimodal approach like ECG and SpO2, performance of Sleep-apnea predicting models can be increased to a level that physicians can rely on. Future research will explore the integration of additional physiological signals like limb movement, chest and abdomen movement etc. and generate recommendations for sleep apnea patients by building recommender systems on top of these results

A Multicast Protocol for Content-Based Publish-Subscribe Systems

The publish/subscribe (or pub/sub) paradigm is a simple and easy to use model for interconnecting applications in a distributed environment. Many existing pub/sub systems are based on pre-defined subjects, and hence are able to exploit multicast technologies to provide scalability and availability. An emerging alternative to subject-based systems, known as content-based systems, allow information consumers to request events based on the content of published messages. This model is considerably more flexible than subject-based pub/sub, however it was previously not known how to efficiently multicast published messages to interested content-based subscribers within a network of broker (or router) machines. In this paper, we develop and evaluate a novel and efficient technique for multicasting within a network of brokers in a content-based subscription system, thereby showing that content-based pub/sub can be deployed in large or geographically distributed settings