Dual stage carrier phase estimation for 16-QAM systems based on a modified QPSK-partitioning

Coherent optical communications based on higher order modulation formats are severely affected by the phase noise of transmitter and receiver lasers. In this work, a novel yet simple scheme is presented for carrier phase estimation (CPE) of 16-ary Quadrature Amplitude Modulation (16- QAM) formats, based on a modified QPSK-partitioning algorithm. The proposed algorithm can tolerate a linewidth times symbol duration product of the order of 1e-4, with 1 dB penalty at a bit error rate (BER) of 1e-3. Tolerance can be further improved by introducing a maximum likelihood estimation (MLE) stage. Comparison of the scheme with other proposed algorithms is shown. The obtained results indicate that the presented approach can be used with the commercially available state of the art lasers for 16-ary Quadrature Amplitude Modulation (16- QAM) transmission at 100 Gbps

Classification of Arrhythmia by Using Deep Learning with 2-D ECG Spectral Image Representation

The electrocardiogram (ECG) is one of the most extensively employed signals used in the diagnosis and prediction of cardiovascular diseases (CVDs). The ECG signals can capture the heart's rhythmic irregularities, commonly known as arrhythmias. A careful study of ECG signals is crucial for precise diagnoses of patients' acute and chronic heart conditions. In this study, we propose a two-dimensional (2-D) convolutional neural network (CNN) model for the classification of ECG signals into eight classes; namely, normal beat, premature ventricular contraction beat, paced beat, right bundle branch block beat, left bundle branch block beat, atrial premature contraction beat, ventricular flutter wave beat, and ventricular escape beat. The one-dimensional ECG time series signals are transformed into 2-D spectrograms through short-time Fourier transform. The 2-D CNN model consisting of four convolutional layers and four pooling layers is designed for extracting robust features from the input spectrograms. Our proposed methodology is evaluated on a publicly available MIT-BIH arrhythmia dataset. We achieved a state-of-the-art average classification accuracy of 99.11\%, which is better than those of recently reported results in classifying similar types of arrhythmias. The performance is significant in other indices as well, including sensitivity and specificity, which indicates the success of the proposed method.Comment: 14 pages, 5 figures, accepted for future publication in Remote Sensing MDPI Journa

Multicultural Teacher Preparation in Practice: A Hermeneutical Disposition

It is a fact that learning to teach is basically a social and practical activity that is supported and informed by theoretical reflections. Field experience and realities should be the core component of any teacher preparation program. That is why, most of the teacher education programs based on theory into practice model. The main aim of this research is not to reject this model, but to sketch out an alternative way of teacher preparation that is based upon teacher’s own context and socio cultural settings or in other words teacher preparation must be organized Hermeneutically. The hermeneutical approach of Hans-Georg Gadamer, is not only of philosophical importance but contains practical implications also. The concepts of understanding, interpretation and application are the core concepts of teacher preparation. In contrast to adopting an entire theory as the guiding principle to the whole content and practice of teacher preparation courses, this research argue for the focus to be on inculcating a hermeneutic disposition in all teachers preparation programs and courses. Hermeneutics is basic to human interaction, especially in dealing with student-teachers belongs to diverse socio-cultural settings or multicultural environment. The main argument or focus of this research is that it is necessary that the teacher preparation programs must be consider the problem of multiculturalism (inter and intra cultural). Multicultural Teacher Preparation (MTP) or hermeneutical mode of teacher preparation plays an important role in the preparation of teachers. It will be helpful for teachers to develop a deep level understanding of students needs belongs to various backgrounds and perspectives, not through applying a predetermined model of classroom activities, but through helping future teachers to recognize their own prejudices and how these help to determine their understandings of diversity in their future classrooms. Developing a hermeneutic disposition in teachers training facilitates and enrich experience of future teachers. A mixed method design was used to conduct the study

Vibration control of a two-story base-isolated building using a new tuned mass multi-sliding friction damper

This paper studies the use of a new Tuned Mass Multi-Sliding Friction Damper (TMMSFD) to increase the damping capacity of seismic isolators installed on a two-story base-isolated building to limit their lateral deformations. The proposed TMMSFD consists of a set of several masses that are laterally attached to the superstructure floor through linear springs. These masses are placed on top of each other one by one and are allowed to slide with respect to each other during the earthquake. The bottom mass that carries the weight of upper masses is in contact with the superstructure floor. The damping of system is supplied by the friction generated along the sliding friction surfaces. The TMMSFD has a low cost of installation, operation, and maintenance compared to common TMDs that use viscous fluid dampers for energy dissipation. The mechanical model of TMMSFD is installed on the numerical model of a two-story base-isolated building equipped with elastomeric rubber bearings in order to evaluate its performance in limiting the displacement of base floor. These models are created by the OpenSEESPy package which is a Python 3 interpreter of OpenSEES. A parametric study is performed to obtain the optimum design parameters of the TMMSFD including its total mass, frequency, and static friction coefficients of the siding surfaces for energy dissipation. The results of time-history analysis of numerical model show that the TMMSFD is capable of limiting the displacement of base floor with a little amount of friction implying its potential as a cost-effective tool for seismic protection

An Entire Coronary System Arising from Right Coronary Cusp: A Rare Anomaly

The prevalence of coronary artery anomalies is approximately 0.6% in individuals undergoing angiography. Most of the anomalies are benign, but some can lead to myocardial infarction, cardiomyopathy, and sudden cardiac death. It is very rare to have an entire coronary circulation that arises from the right coronary cusp. We present a case of a 57-year-old male who presented with complaints of chest pain and dyspnea on exertion. An invasive angiogram revealed all the three coronary arteries originating from the right coronary cusp. It is crucial to define coronary anatomy as anomalies dictate which cardiac intervention should be attempted in cases of ischemia

Influence of Natural Zeolite and Paraffin Wax on Adhesion Strength Between Bitumen and Aggregate

Asphalt mixture that is used for the construction of flexible pavements is mainly composed of two constituents i.e. bitumen and aggregate. Sturdy adhesion among bitumen and aggregate is the sign of durability of asphalt pavements. Adhesion is considered as one of the most important factors for sustainable asphalt pavement. This is the motive why its miles utmost important to deeply understand the phenomenon of adhesion considering the effect of alternate in temperature, moisture conditions. In this study softer binder 80/100 was selected that has less adhesion compared to hard pen grades. Limestone aggregates which is commonly used for the construction of asphalt pavements has also been selected. Two types of modifiers (Zeolite and Paraffin Wax) were selected because of the extensive use in asphalt foaming and the polymer modified asphalt mixtures as temperature reducing agent. To investigate the strength of adhesive bond, Bitumen Bond Strength (BBS) was performed at different temperatures, in dry, and wet conditions. To quantify the effect of modifiers on penetration grade and softening point conventional testing is performed. For performance grading, the PG test was performed using Dynamic Shear Rheometer. The comparisons were developed among pull of tensile strength at dry and after 72hrs water conditioning while preserving the temperature at 25 .To check the effect of temperature BBS is performed at 15 . The results illustrate that 2% zeolite shows best results in terms of adhesion and performance grade while Paraffin wax has less adhesion and poor performance grade

A Rare Case of Adult Congenital Heart Disease: Single Ventricular Chamber with Anomalous Right Coronary Artery in an Octogenarian

ABSTRACT Patients with single-ventricle physiology encompass a wide array of anatomic subtypes, including but not limited to: tricuspid atresia, hypoplastic left heart syndrome, doubleoutlet or double-inlet ventricles. The outcomes for patients with single ventricle born before 1990 are relatively poor. An 81-year-old female presented to the hospital as non-ST elevation myocardial infarction. She was started on antiplatelet and anticoagulation. Echocardiogram revealed a single ventricle which was thought to be left ventricle with possible transposition of great vessels. Angiography was performed that identified the single ventricle and anomalous origin of the right coronary artery (RCA). She was also found to have double vessel coronary artery disease with diffuse stenosis of mid-RCA at 80% and proximal circumflex at 95%. She was managed conservatively as was high risk for CABG given her rare congenital condition. Patients with single ventricle are at risk of long-term morbidity, including heart failure, neurological injury, and early death. The mortality risk of these patients is high as most of the patients without corrective surgery do not proceed to adulthood. Our case had multivessel coronary artery stenosis along with a rare presentation of congenital heart disease in adulthood. The patient was offered percutaneous coronary intervention, but she declined and chose to be treated conservatively with only medical management. We present a rare case of an elderly female surviving with a single ventricular chamber. The patient is an exception to the usual process of the pathology as most patients without corrective surgery seldom survive into adulthood