scholarly journals Chaos in a deformed Dicke model

2022 ◽  
Author(s):  
Ángel L. Corps ◽  
Rafael A Molina ◽  
Armando Relaño
Keyword(s):  
Quantum Phase Transitions ◽  
Semiclassical Limit ◽  
Critical Energy ◽  
Initial Condition ◽  
Quantum Case ◽  
Constant Of Motion ◽  
Onset Of Chaos ◽  
Parity Symmetry ◽  
Dicke Model ◽  
The Impact

Abstract The critical behavior in an important class of excited state quantum phase transitions is signaled by the presence of a new constant of motion onlyat one side of the critical energy. We study the impact of this phenomenon in the development of chaos in a modified version of the paradigmatic Dicke model of quantum optics, in which a perturbation is added that breaks the parity symmetry. Two asymmetric energy wells appear in the semiclassical limit of the model, whose consequences are studied both in the classical and in the quantum cases. Classically, Poincar ́e sections reveal that the degree of chaos not only depends on the energy of the initial condition chosen, but also on the particular energy well structure of the model. In the quantum case, Peres lattices of physical observables show that the appearance of chaos critically depends on the quantum conserved number provided by this constant of motion. The conservation law defined by this constant is shown to allow for the coexistence between chaos and regularity at the same energy. We further analyze the onset of chaos in relationwith an additional conserved quantity that the model can exhibit.

Numerical Simulation and Analysis on the Impact Effect of Cylindrical Projectile Impacting Shelled Explosive

2013 ◽  
Vol 710 ◽  
pp. 320-324
Author(s):  
Ying Zi Jiang ◽  
Wei Li Wang ◽  
Xue Feng Huang ◽  
Lei Fu ◽  
Zhuang Qing Fan
Keyword(s):  
Numerical Simulation ◽  
Energy Criterion ◽  
Critical Energy ◽  
Simplified Model ◽  
Initiation Point ◽  
4340 Steel ◽  
Simulation Results ◽  
The Impact ◽  
Explosive Detonation ◽  
Critical Initiation

The numerical simulation of shelled Comp.B explosive was studied following the Lee-Tarver ignition and growth model when it was impacted respectively by 4340 Steel, OFHC and 93#W projectile with the same mass; the influences on explosive detonation of the initiation process, the material of projectile and the L/D ratio of projectile were analyzed; the critical initiation speeds of the projectiles of three different materials with different L/D ratio were gained. In order to verify the simulation results, the questions were calculated by the theoretical simplified model, the results of the theoretical calculation and the numerical simulation accorded well based on critical energy criterion. The results show that the capability of igniting explosive, the first is 93#W, the second is OFHC, the last is 4340 Steel; The initiation point were not on the interface of shell and explosive, and the faster of the impacting velocity, the initiation point closer the interface; the bigger of the L/D ratio of projectile, the higher of the critical initiation speed.

scholarly journals Information geometry and quantum phase transitions in the Dicke model

2012 ◽  
Vol 86 (3) ◽  
Author(s):  
Anshuman Dey ◽  
Subhash Mahapatra ◽  
Pratim Roy ◽  
Tapobrata Sarkar
Keyword(s):  
Phase Transitions ◽  
Quantum Phase Transitions ◽  
Information Geometry ◽  
Quantum Phase ◽  
Dicke Model

Role of initial condition and parametric uncertainty in a severe hailstorm forecast

2021 ◽  
Author(s):  
Patrick Kuntze ◽  
Annette Miltenberger ◽  
Corinna Hoose ◽  
Michael Kunz
Keyword(s):  
Initial Conditions ◽  
Weather Prediction ◽  
Parametric Uncertainty ◽  
Radar Data ◽  
Cloud Microphysics ◽  
Initial Condition ◽  
Relative Contribution ◽  
Cloud Properties ◽  
Set Up ◽  
The Impact

<p>Forecasting high impact weather events is a major challenge for numerical weather prediction. Initial condition uncertainty plays a major role but so potentially do uncertainties arising from the representation of physical processes, e.g. cloud microphysics. In this project, we investigate the impact of these uncertainties for the forecast of cloud properties, precipitation and hail of a selected severe convective storm over South-Eastern Germany.<br>To investigate the joint impact of initial condition and parametric uncertainty a large ensemble including perturbed initial conditions and systematic variations in several cloud microphysical parameters is conducted with the ICON model (at 1 km grid-spacing). The comparison of the baseline, unperturbed simulation to satellite, radiosonde, and radar data shows that the model reproduces the key features of the storm and its evolution. In particular also substantial hail precipitation at the surface is predicted. Here, we will present first results including the simulation set-up, the evaluation of the baseline simulation, and the variability of hail forecasts from the ensemble simulation.<br>In a later stage of the project we aim to assess the relative contribution of the introduced model variations to changes in the microphysical evolution of the storm and to the fore- cast uncertainty in larger-scale meteorological conditions.</p>

 The Climate Response to Emissions Reductions due to COVID-19

2021 ◽  
Author(s):  
Chris Jones ◽  
Keyword(s):  
Atmospheric Composition ◽  
Shortwave Radiation ◽  
Initial Condition ◽  
Emissions Reductions ◽  
Near Surface ◽  
Surface Climate ◽  
Climate Signals ◽  
Near Term ◽  
Regional Analyses ◽  
The Impact

<p>Many nations responded to the COVID-19 pandemic by restricting travel and other activities during 2020, resulting in temporarily reduced emissions of CO2, other greenhouse gases and ozone and aerosol precursors. We perform a coordinated Intercomparison, CovidMIP, of Earth System model simulations to assess the impact on climate of these emissions reductions. Eleven models performed multiple initial-condition ensembles to produce over 280 simulations spanning both initial condition and model structural uncertainty. We find model consensus on reduced aerosol amounts (particularly over East Asia) and associated increases in surface shortwave radiation levels. However, any impact on near-surface temperature or rainfall during 2020-2024 is extremely small and is not detectable in this initial analysis. Regional analyses on a finer scale, and closer attention to extremes (especially linked to changes in atmospheric composition and air quality) are required to test the impact of COVID-19-related emission reductions on near-term climate.</p><p>This first-look at results has focussed on surface climate, but future analysis will include attribution of drivers of climate signals; longer term implications of emissions reductions and options for economic recovery; quantifying changes in extremes; influence on atmospheric circulation and the carbon cycle.</p>

Evaluation of Available Transfer Capability Using Transient Stability Constrained Line Flows

2014 ◽  
Vol 15 (1) ◽  
pp. 59-68
Author(s):  
Lazarus Okechukwu Uzoechi ◽  
Satish M. Mahajan
Keyword(s):  
Transient Stability ◽  
Direct Determination ◽  
Computation Time ◽  
Critical Energy ◽  
Energy Performance ◽  
Electric Power System ◽  
Available Transfer Capability ◽  
Transfer Capability ◽  
The Stability ◽  
The Impact

Abstract This paper presents a methodology to evaluate transient stability constrained available transfer capability (ATC). A linear and fast line flow–based (LFB) method was adopted to optimize the ATC values. This enabled the direct determination of the system source–sink locations. This paper formulated different market transactions considering bilateral and multilateral impacts in the stability constrained ATC. The proposed method was demonstrated on the WECC 9-bus and IEEE 39-bus systems. The critical energy performance index (CEPI) enabled the direct identification of candidates for contingency screening based on ranking. This index helped to reduce the list of credible contingencies for ATC evaluation and, therefore, the computation time. The results of the proposed ATC method are consistent with the literature and can be deployed for fast assessment of the impact of transactions in an electric power system.

IMPACT FORCE RESPONSE OF SHORT CONCRETE FILLED STEEL TUBULAR COLUMNS UNDER AXIAL LOAD

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1361-1368 ◽  
Author(s):  
GOUPING REN ◽  
ZHU LI
Keyword(s):  
Impact Force ◽  
Time History ◽  
Material Model ◽  
Critical Energy ◽  
Steel Tube ◽  
Peak Force ◽  
Impact Speed ◽  
Tubular Columns ◽  
Unitary Model ◽  
The Impact

The impact test on short concrete filled steel tubular column was conducted through DHR-9401 dropped hammer tester. Based on analysis on recorded time-history curve of impact force, the relations of impact force with respect to confining effect coefficient and impact speed are obtained. So are done that of the impact duration. By use of ANSYS/LS-DYNA, values of impact peak force in relation with those of impact speed were computed in the case of unitary material model and composite material model respectively. The simulation results show that peak force-speed curve of unitary model has better description of test data than that of composite one. Critical energy is found to increase linearly with the steel ratio when steel tube and concrete remain unchanged.

scholarly journals Analysis of GDP using the n-variable Regression Model

2021 ◽  
pp. 170-175
Author(s):  
Krishna Kumar Chaudhary ◽  
Anjay Kumar Mishra
Keyword(s):  
Regression Model ◽  
Informal Economy ◽  
Service Sector ◽  
Initial Conditions ◽  
Policy Research ◽  
Secondary Data ◽  
Policy Formulation ◽  
Initial Condition ◽  
Independent Variables ◽  
The Impact

Purpose: Gross Domestic Product(GDP) depends on Agriculture, Service, and industry performance. The main aim of the study is to assess the relationship between dependent variable GDP and Independent variables agriculture, industry, and service sector by using the n-variable Regression Model at initial condition. Design/Methodology/Approach: The study is an application of the n-variable Regression Model at the initial condition to analyze the situation of GDP along with reasons not becoming zero GDP even after using the initial condition. The secondary data of the GDP of Nepal from the Central Bureau of Statistics of 10 years till 2019/20 has been analyzed. By finding cofactors of correlation coefficient matrix, Mean and standard deviation of the individual data to establish the linear relationship between dependent and independent variable. Findings/Result: Under initial conditions, if all the independent variables zero, the GDP is −751028.431 billion, negative sign shows that GDP decreases highly if the entire major factor has no role in GDP. It is non-zero GDP. It means in the 11th year the stated amount will be expended from the previous year saving for forex to import which will not be possible in a sustainable economy. It will not be possible in real conditions however it may be hypothetical possible either because of the impact of informal economy or disinvestment or negative net exports. It is significant for forecasting the future GDP of a country effectively assuming different conditions for policy formulation. Originality/Value: It is the first empirical research using the n-variable Regression Model for GDP Analysis. Paper Type: Analytical Policy Research

scholarly journals THE IMPACT OF RELOCATION FROM SLUM TO SIMPLE RENTED FLATS ON THE HEALTH OF RESIDENTS AT KAMPUNG PULO

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Pebrianto Syafruddin ◽  
Isbandi Rukminto Adi
Keyword(s):  
Local Government ◽  
Qualitative Study ◽  
Rainy Season ◽  
Skin Diseases ◽  
Health Condition ◽  
Health Facilities ◽  
Initial Condition ◽  
Fundamental Change ◽  
Raw Water ◽  
The Impact

This research discussed the impact of relocating from Kampung Pulo in East Jakarta that was exposed to the environment by the local government of the capital (DKI) Jakarta due to their initial condition occupying the slums on the Ciliwung River were often affected by flooding when the rainy season. The research also illustrated the impact of relocation on the health of Kampung Pulo residents in their environment, health facilities and reality they perceived. This research was a qualitative study presented descriptively. The results stated that there were changes, namely changes that occurred in the health condition of Kampung Pulo residents, when the flood felt the mud entered into their homes and the threat of diseases such as diarrhea, vomit and skin diseases aggravated by the condition of unavailability of sanitation, such as the availability of toilets and water needs and could be seen that many of their homes di not have such facilities. But after the relocation they got excellent sanitation and water proved in each unit of flats had a lavatory, raw water that can be cooked to be used to cook and drink, a sink as well as a clean and separate cooking place, other than that. This research could also see that the health level of Kampung Pulo residents increased, they were not suffering from any disease as suffered at Kampung Pulo, a fundamental change in their health.

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