Sharif Digital Repository

Numerical simulation of liquefaction-induced lateral spreading in gently sloped sandy layers requires fully coupled dynamic hydro-mechanical analysis of saturated sandy soil subjected to seismic loading. In this study, a fully coupled finite element model utilizing a critical-state two-surface-plasticity constitutive model has been applied to numerically investigate the effects of surface/subsurface geometry on lateral spreading. Using a variable permeability function with respect to excess pore pressure ratio is another distinctive feature of the current study. The developed code has been verified against the results of the well-known VELACS project. Lateral spreading phenomenon has been... 

We report CCD V and I time series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precision better than 0.05 mag for stars brighter than V ~ 19.0 mag, even in the crowded central regions of the cluster. The high photometric precision has resulted in the discovery of twonew RRc stars, three eclipsing binaries, seven long-term variables and one field RRab star behind the cluster. A detailed identification chart and equatorial coordinates are given for all the variable stars in the field of our images of the cluster. Our data together with the literature V-data obtained in 1994 and 1995 allowed us to refine... 

One way to reduce vehicles' fuel consumption (FC) is to optimize different parts of its powertrain. Among different modern powertrains, continuously variable transmission (CVT) is one of the common types which changes speed ratio between engine and wheels, continuously. Therefore, the CVT allows the engine to operate at its fuel-optimal speed. Due to the limited power transmission capacity and speed ratio range of the CVT, researchers attempted to combine the CVT with a planetary gear train and a fixed ratio mechanism. This mechanism is called infinitely variable transmission (IVT). In this study, a multi-speed gearbox (MSG) is used in the IVT and its impact on the powertrain performance and... 

One solution to reduce fuel consumption (FC) of vehicles is to use infinitely variable transmission (IVT) as the power train. However, inappropriate design of IVT leads to an inadequate decrease in the vehicle FC. Therefore, in order to reach a maximum fuel economy, an optimization on the power train proves to be necessary. The present article aims to optimize IVT to decrease the vehicle FC in a driving cycle. The results have revealed that the FC of the vehicle equipped with the optimized IVT is approximately 7% and 4.7% compared to the cases of using the optimized six-speed and nine-speed manual transmissions, respectively  

This letter is concerned with the blow-up of the solutions to a semilinear parabolic problem with a reaction given by a variable exponent. Lower bounds for the time of blow-up are derived if the solutions blow up  

Induction motor parameter estimation is generally needed for such purposes as fault detection and the achievement of high dynamic performance drives. This paper is an attempt to use variable structure control (VSC) methodology for the on-line estimation of several significant mechanical and electrical induction motor parameters. The estimated parameters are rotor resistance, magnetizing inductance, stator resistance and viscous damping coefficient In this combined control/estimation method, we propose to apply field-oriented control to the non-linear model of induction motor, and then transform the model by Input-state linearization into canonical form. Application of variable structure... 

In this paper, a fuzzy random minimum cost flow problem is presented. In this problem, cost parameters and decision variables are fuzzy random variables and fuzzy numbers respectively. The object of the problem is to find optimal flows of a capacitated network. Then, two algorithms are developed to solve the problem based on Er-expected value of fuzzy random variables and chance-constrained programming. Furthermore, the results of two algorithms will be compared. An illustrative example is also provided to clarify the concept  

In this paper, first a fuzzy random resource-constrained project scheduling problem is presented. The object of the problem is to find the optimal scheduling of project activities. In this model, duration of project activities is a fuzzy random variable. Then, the proposed model is formulated by using the expected value of fuzzy random variables as an IP model. An illustrative example is also provided to clarify the concept. © 2010 World Academic Press, UK. All rights reserved  

This study aims to identify the learning orientations and language learning strategies of the students, to determine whether there are any significant differences in the motivational orientations and language learning strategies preferences between male and female learners, and investigate whether there is a relationship between students' motivational orientations and strategy preferences. A total of 206 intermediate level students who studied in English in private language institutes were asked to complete two questionnaires. One was used to identify students' motivational orientations and the other was used to identify students' learning strategies. Statistical analyses demonstrated that... 

The Galactic bulge source MOA-2010-BLG-523S exhibited short-term deviations from a standard microlensing light curve near the peak of an A max ∼ 265 high-magnification microlensing event. The deviations originally seemed consistent with expectations for a planetary companion to the principal lens. We combine long-term photometric monitoring with a previously published high-resolution spectrum taken near peak to demonstrate that this is an RS CVn variable, so that planetary microlensing is not required to explain the light-curve deviations. This is the first spectroscopically confirmed RS CVn star discovered in the Galactic bulge  

Employing profiles using variable sample size (VSS) may improve its effectiveness and hence is investigated in this paper. Besides, the implementation cost of a profile is an important factor in determining the main parameters. In this paper, the Lorenzen-Vance function is first extended to model implementation cost of VSS linear profiles. Then, the resulted economic model is solved using a genetic algorithm (GA). The average run length criterion when process is in control, ARL0 and the average run length measure when process goes out of control, ARL1 , is used to evaluate statistical properties of the designed profile. Moreover, a sensitivity analysis on the main parameters of the... 

The main purpose of this article is to generalize a characterization of Lipschitz functions in the context of metric-measure spaces. The results are established in the class of metric-measure spaces which satisfy a strong version of the doubling (Bishop-Gromov regularity) condition. Indeed, we establish a necessary and sufficient condition in order that any measurable function which satisfies an integrability condition to be essentially Lipschitzian. © 2019 Elsevier Inc  

Variable-temperature 1H and 13C NMR spectroscopy are used to investigate barrier of C-N rotation in series of amides, such as N-benzoyl pyrrolidine, N-(4-chlorobenzoyl) pyrrolidine, N-(4-methoxybenzoyl) pyrrolidine, N-(4-chlorobenzoyl) piperidine, and N-(4-methoxybenzoyl) piperidine. Δ G298≠ of 65.2, 60.6, 58.8, 60.1, and 57.1 kJ mol-1are found for the above compounds, respectively. Theoretical studies were done for these compounds and the results showed good agreement with the experimental results. Theoretical and experimental results showed that substituted methoxy group on the para position of benzene ring decreases the rotational barrier. Increasing steric effect and therefore... 

One of the main challenges in RoboCup is to maintain a high level of speed and accuracy in decision making and performing actions by the robot players. Although we might be able to use complicated hardware and software on the robots to achieve the desired accuracy, but such systems might not be applicable in real-time RoboCup environment due to their high processing time. This is quite serious for the robots equipped with more than one vision systems. To reduce the processing time we developed some basic ideas that are inspired by a number of features in the human vision system. These ideas included efficient need-based vision, that reduces the number of objects to be detected to a few... 

The Poincaré inequality is extended to uniformly doubling metric-measure spaces which satisfy a version of the triangle comparison property. The proof is based on a generalization of the change of variables formula