Endomorphism rings of modules over prime rings

Endomorphism rings of modules appear as the center of a ring, as the fix ring of ring with group action or as the subring of constants of a derivation. This note discusses the question whether certain *-prime modules (introduced by Bican et al.) have a prime endomorphism ring. Several conditions are presented that guarantee the primness of the endomorphism ring. The contours of a possible example of a *-prime module whose endomorphism ring is not prime are traced.Comment: 9 page

Parametric Study of the Response of Single Pile under Lateral Loading at the Pile Head

This paper presents the findings of numerical studies based on the finite difference method for assessment of single pile behavior under simple dynamic lateral loads. At first, the results of an experimental dynamic lateral load test on a pipe pile driven in to sandy soil are compared with the results of this numerical modeling and some parameters are back calculated. Then piles with different length to diameter ratio, subjected to simple harmonic vibrations (sinusoidal vibrations) with different magnitudes of load and with a range of frequencies, are modeled. The load transferred to the pile and pile head displacement is calculated. Finally, the effects of load frequency, soil- pile damping ratio and length to diameter ratio of pile on the behavior of pile foundation is determined. The results show that the magnitude of load and length to diameter ratio of pile have significant effect on pile response under harmonic lateral loads; displacement of the pile head increases, with increase in load magnitude and decrease in length to diameter ratio of pile. For the range of frequency studied in this paper (1 to 15 Hz), observed that this parameter doesn’t affect the pile head response

Evaluation of Deformation Behavior of Quay Walls Under Earthquake Loading

Ports are often regional economic centers and important components of regional and local transportation lifeline systems. Because of these reasons, the downtime of the ports due to natural disaster such as an earthquake results in severe economic loss. Gravity quay walls are the most common type of construction for docks because of their durability, ease of construction and capacity to reach deep seabed levels. Past earthquakes demonstrated that the seismic behavior of port structures such as quay walls was significantly governed by the properties of soils. The 1995 Hyogoken- Nanbu (Kobe) Earthquake brought great damage to structures in the Port of Kobe, which is one of the primary ports in Japan. In the present work, caisson type quay wall, damaged by 1995 Hyogoken- Nanbu earthquake, is first numerically analyzed and then seismic behavior of quay wall is investigated. The results are also compared with the observed data consisting seaward displacement, tilting and settlement. The results of the numerical analyze shows good agreement between the numerical simulations and observed data

Evaluation of the Martin et al. (1975) Pore Pressure Build Up Model Using Laboratory Test Data

Liquefaction has occurred during numerous earthquakes and it has caused damages and catastrophic failures. This phenomenon takes place due to the excess pore pressure development in loose saturated granular soils. Researchers have attempted to predict these phenomena (excess pore water pressure and liquefaction) using constitutive modeling and numerical approaches. In this paper, a numerical modeling procedure is presented to predict the seismic excess pore water pressure using a fully coupled effective stress analysis. A few cyclic and monotonic element tests and a level ground centrifuge test conducted during VELACS project were utilized to calibrate the numerical models. The Mohr-Coulomb elastic-perfectly plastic and the Martin et. al. (1975) excess pore water pressure build up models were concurrently incorporated in the analysis. This study focuses on a reasonable step by step procedure in order to adjust and obtain the calibration parameters of these models. Comparing the excess pore pressure buildup time histories of the numerical and experimental models (both element and centrifuge tests) showed that the Martin et al. (1975) models can be used in the numerical assessment of excess pore water pressure with an acceptable degree of preciseness

Response of Piled Raft Foundation on Soft Clay Under Seismic Load

A number of researchers has extensively investigated the vertical load bearing mechanism of piled raft foundation, by applying elasticity theory and finite element method. The study on the load bearing mechanism under horizontal loading or during earthquakes, however, is very limited. This is partially because piled raft foundations are considered as raft foundations in the current design practice. Since the behavior of a piled raft foundation during earthquakes is considered fairly complex due to dynamic interaction among a raft, piles and a soil, the design procedure should include the effect of this mechanism in an appropriate manner. In other hands, the behavior of piled raft foundations under earthquake loading is an important factor affecting the performance of structures. Observations from past earthquakes have shown that piles in firm soils generally perform well, while those installed in soft or liquefiable soils are more susceptible to problems arising from ground amplification or excessive soil movements. This research comprises three major components: (1) Numerical modeling of piled raft foundation using finite element program (ABAQUSE), (2) verification of numerical program with dynamic centrifuge tests on clay pile-raft systems, and (3) performing parametric studies. The acceleration predicted by numerical method is well matched with the measured acceleration in a centrifuge test when simulating a piled raft foundation

A novel energy management model among interdependent sections in the smart grids

Technically, residential energy management systems are fundamental sectors in the smart grids for implementing demand response programs in the layer of households for managing energy consumption and reducing energy bills. The paper proposes a novel energy management scheme that takes production and usage into account based on a heuristic searching operation. In addition to modelling the grid, renewable energy sources, batteries, and electric vehicles, various kinds of electrical and thermal devices have been examined, including air conditioners, water heaters, vacuum cleaners etc. A method is developed for solving the objective constraint issue in a smart home in order to reduce energy consumption and determine feasible operation states among the various loads. Moreover, this paper proposes a grey wolf optimization method for solving the issue over a longer simulation period. Various cases were examined to evaluate the effectiveness of this suggested robust optimization algorithm. The outcomes show that the suggested model could not only reduce energy costs significantly but has also shown good performance for energy management purposes.© 2022 The Authors. IET Generation, Transmission & Distribution published by John Wiley & Sons Ltd on behalf of The Institution of Engineering and Technology. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.fi=vertaisarvioitu|en=peerReviewed

The Effects of Canyon Topography on Dynamic Stress Distribution in Earth Dams

Limitations of computer storage capacity and high costs have generally restricted the use of numerical methods to two-dimensional dynamic analyses of earth dams. However, differences in canyon topographies in which the earth dams have been built may cause various constraining effects. Comparison between results of plane strain and three-dimensional dynamic analyses may reflect the site effects especially in narrow canyons. Consequently, considering the geometry of canyon, one may choose an appropriate method of dynamic analysis. This paper presents the effect of different canyon geometries on amount and distribution of induced dynamic stresses in plane strain and in three-dimensional analyses. These analyses are executed by FLAC2D and FLAC3D for some sections of earth dams with different length to height ratios. It has been shown that the ratios of plain strain to 3D dynamic shear stresses reach their maximum and minimum values in triangular and rectangular shaped canyons, respectively. With complimentary studies the actual seismic behavior of earth dams could be estimated from plane strain dynamic analyses