An RHT-Model-Based Equivalent Parameter Scheme for Blast Response Simulation of RC Frames

In this paper, a novel equivalent parameter scheme based on the Riedel–Hiermaier–Thoma (RHT) model is proposed for blast response simulations of reinforced concrete (RC) frames. Considering the strengthening effect of longitudinal and stirrup reinforcements on concretes, constitutive parameters in the RHT model are modified to homogenize RC components based on reasonable simplifications and numerical tests. Numerical results of RC beams illustrate that this scheme significantly improves the computational efficiency and effectively predicts real explosion response behaviors with high accuracy. The scheme is then employed for the blast simulation of an RC frame with multiple components with results compared with those of real frame experiments to further demonstrate its reliability. Owing to its efficiency and accuracy, the present RHT-model-based equivalent parameter scheme can serve as a feasible tool to conduct blast response analysis of the RC frame and guide the corresponding anti-explosion designs.

A four-parameter system for rationalising the electronic properties of transition metal–radical ligand complexes

A heuristic four-parameter scheme captures and predicts the electronic properties of radical-ligand transition metal compounds, overcoming ligand specific descriptions.

Protection Scheme using RPI Concept in STATCOM Compensated EHV System

This research work present a protection scheme for fault detection and fault classification in EHV with static synchronous compensator (STATCOM) using Regulated Power index (RPI) concept. RPI per phase is defined as the ratio of the sum of sending end apparent power and receiving end apparent power to the apparent power at receiving end for that phase [1]. STATCOM is used for reactive power compensation and regulates the system voltage by absorbing and generating reactive power. As per the requirement of system parameter scheme is developed for the detection of fault, identification of faulty phase and tripping the faulty phase. This scheme will be validated by considering various fault test cases considering severe fault conditions with very low resistance, high fault resistance conditions and internal faults with static synchronous compensator (STATCOM) at sending end on the MATLAB model of transmission system at 220 KV level.

A Sensitivity Study of an Effective Aerodynamic Parameter Scheme in Simulating Land–Atmosphere Interaction for a Sea–Land Breeze Case Around the Bohai Gulf of China

Numerical simulations of the atmospheric boundary layer require careful representation of the surface heterogeneity, which involves the upscaling parameterization scheme for the heterogeneous surface parameters. In this study, the sensitivity comparisons of an effective aerodynamic parameter scheme against the area-weighted average scheme in simulating the land–atmosphere interaction over heterogeneous terrain were carried out by conducting multinested simulations with the Weather Research and Forecasting (WRF) Model at coarse and fine resolutions, for a typical sea–land breeze case in the Bohai Gulf of China. The results show that the limited-area model is sensitive to the aerodynamic parameter scheme and the effective aerodynamic parameter scheme exhibits a better performance in simulating the variables and parameters in the land–atmosphere interaction process, such as surface wind speed, sensible heat flux, latent heat flux, friction velocity, and surface air temperature, among others, for short-term simulations. Particularly, the underestimation of sensible heat flux and overestimation of latent heat flux over heterogeneous terrain with area-weighted average scheme for aerodynamic parameters can be improved with the effective parameter scheme in the coastal regions, where the mean simulation error with the effective parameter scheme is about one-half of that with the average scheme for sensible heat flux and one-third for latent heat flux.

Study of properties of a finite-difference scheme for the advection stage implementation in the lattice Boltzmann method

Исследуется конечно-разностная однопараметрическая схема для решения системы уравнений переноса, возникающей при применении метода расщепления по физическим процессам к задачам для системы кинетических уравнений. Исследование устойчивости проводится с помощью метода Неймана, построена область устойчивости на плоскости "параметр схемы-число Куранта". Показано, что за счет выбора параметра можно влиять на дисперсионные и диссипативные свойства схемы. Реализован подход к выбору оптимального параметра, основанный на оптимизации дисперсионных и диссипативных поверхностей. Эффективность схемы при оптимальном значении параметра показана при численном решении задач о течении в каверне и о волнах сдвига в вязкой жидкости. A finite-difference single-parameter scheme for solving the system of advection equations arising in the application of the method of splitting into physical processes to a system of kinetic equations is studied. The stability analysis is performed using the Neumann method. A stability domain in the "scheme's parameter-Courant number" plane is constructed. It is shown that an appropriate choice of this parameter allows one to regulate the dispersive and dissipative properties of the scheme. An approach of choosing the optimal parameter is proposed on the basis of an optimization of dispersive and dissipative surfaces. An efficiency of the scheme with the optimal parameter is illustrated by the numerical solution of the cavity flow problem and the problem on the propagation of shear waves in viscous fluid.

Stochastic and Perturbed Parameter Representations of Model Uncertainty in Convection Parameterization*

It is now acknowledged that representing model uncertainty in atmospheric simulators is essential for the production of reliable probabilistic forecasts, and a number of different techniques have been proposed for this purpose. This paper presents new perturbed parameter schemes for use in the European Centre for Medium-Range Weather Forecasts (ECMWF) convection scheme. Two types of scheme are developed and implemented. Both schemes represent the joint uncertainty in four of the parameters in the convection parameterization scheme, which was estimated using the Ensemble Prediction and Parameter Estimation System (EPPES). The first scheme developed is a fixed perturbed parameter scheme, where the values of uncertain parameters are varied between ensemble members, but held constant over the duration of the forecast. The second is a stochastically varying perturbed parameter scheme. The performance of these schemes was compared to the ECMWF operational stochastic scheme, stochastically perturbed parameterization tendencies (SPPT), and to a model that does not represent uncertainty in convection. The skill of probabilistic forecasts made using the different models was evaluated. While the perturbed parameter schemes improve on the stochastic parameterization in some regards, the SPPT scheme outperforms the perturbed parameter approaches when considering forecast variables that are particularly sensitive to convection. Overall, SPPT schemes are the most skillful representations of model uncertainty owing to convection parameterization.

Iteration Complexity of the Alternating Direction Method of Multipliers for Quasi-Separable Problems in Multi-Disciplinary Design Optimization

The Alternating Direction Method of Multipliers (ADMM) is a distributed algorithm suitable for quasi-separable problems in Multi-disciplinary Design Optimization. Previous authors have studied the convergence and complexity of the ADMM algorithm by treating it as an instance of the proximal point algorithm. In this paper, those previous results are extended to an alternate form of the ADMM algorithm applied to the quasi-separable problem. Secondly, a dynamic penalty parameter updating heuristic for the ADMM algorithm is introduced and compared against a previously proposed updating heuristic. The proposed updating heuristic was tested on a distributed linear model fitting example and performed favorably against the other heuristic and the fixed penalty parameter scheme.

A Modified Q Parameter Scheme Based on BIBD in RFID

Radio Frequency Identification is an Automatic Identification Technology. RFID system typically consists of a reader and a number of tags. When more than one tag send signal to reader at the same time, reader will not identify any one. This is called collision. The information of collision is regarded as uselessness in the conventional algorithms. But in fact, useful information can be extracted from the collision and the reading efficiency can be improved. In this paper, tags use BIBD(16,4,1) blocks instead of RN16, the reader analyses the collision information based on the characteristics of BIBD and makes valid recognition even when more than one tag have been detected in same time slot. The theoretical and simulation results show that the proposed algorithm can improve the reading efficiency by 100% than that of the conventional Q algorithm. Furthermore, the proposed scheme changes little to the existing standard, easy to implement and compatible for EPC Global Code.