Low-frequency phase diagram of irradiated graphene and periodically driven spin-1/2 XYXY chain

We study the Floquet phase diagram of two-dimensional Dirac materials such as graphene and the one-dimensional (1D) spin-1/2 $XY$ model in a transverse field in the presence of periodic time-varying terms in their Hamiltonians in the low drive frequency ($\omega$) regime where standard $1/\omega$ perturbative expansions fail. For graphene, such periodic time dependent terms are generated via the application of external radiation of amplitude $A_0$ and time period $T = 2\pi/\omega$, while for the 1D $XY$ model, they result from a two-rate drive protocol with time-dependent magnetic field and nearest-neighbor couplings between the spins. Using the adiabatic-impulse method, we provide several semi-analytic criteria for the occurrence of changes in the topology of the phase bands of such systems. For irradiated graphene, we point out the role of the symmetries of $H(t)$ and $U$ behind such topology changes. Our analysis reveals that at low frequencies, phase band topology changes may also happen at $t= T/3, 2T/3$ (apart from $t=T$). We chart out the phase diagrams at $t=T/3, 2T/3,\, {\rm and }\, T$ as a function of $A_0$ and $T$ using exact numerics, and compare them with the prediction of the adiabatic-impulse method. We show that several characteristics of these phase diagrams can be analytically understood from results obtained using the adiabatic-impulse method and point out the crucial contribution of the high-symmetry points in the graphene Brillouin zone to these diagrams. Finally we study the 1D $XY$ model with a two-rate driving protocol using the adiabatic-impulse method and exact numerics revealing a phase band crossing at $t=T/2$ and $k=\pi/2$. We also study the anomalous end modes generated by such a drive. We suggest experiments to test our theory.Comment: v1; 26 pages, 19 Fig

Design and Implementation of Soft Switching Boost Converter

The design and implementation of closed loop soft switching boost DC-DC converter have been proposed. The staedy state analysis of open loop converter with operational modes are evaluated. Equations for the design of all the circuit parametrs are attainted and discussed in details for simulation and experimental purpose. The proposed circuit has resonant circuit which has one inductor and two capacitor to achieve soft switching of converter by operating it at zero voltage condition

A SURVEY ON MACHINE LEARNING APPROACH TO MAINFRAME ANALYSIS

Mainframe system processing includes a Batch Cycle†that approximately spans in regular interval on a daily basis. The core part of the cycle completes in the middle of the regular interval with key client deliverables associated with the end times of certain jobs are tracked by service delivery. There are single and multi-client batch streams, a QA stream which includes all clients, and about huge batch jobs per day that execute. Despite a sophisticated job scheduling software and automated system workload management, operator intervention is required. The outcome of our proposed work is to bring out the high priority job first. According to our method, the jobs are re-prioritized the schedules so that prioritized jobs can get theavailable system resources. Furthermore, the characterization, analysis, and visualization of the reasons for a manual change in the schedule are to be considered. This work requires extensive data preprocessing and building machine learning models for the causal relationship between various system variables and the time of manual changes.Â