geometric conditions
Recently Published Documents


TOTAL DOCUMENTS

398
(FIVE YEARS 125)

H-INDEX

22
(FIVE YEARS 5)

2022 ◽  
Vol 961 (1) ◽  
pp. 012052
Author(s):  
Sura Tawfeeq Al-Auqbi ◽  
Nahla M. Salim ◽  
Mahmood R. Mahmood

Abstract The stone column technique is an effective method to increase the strength of soft cohesive soil, which results in a reduction in foundation settlement and an increase in bearing capacity. The topic of restraining creep settlement through the use of stone columns techniques has gained increasing attention and consideration; because stone columns are widely used to treat soft soil deposits, caution should be applied in estimating creep settlement. We discovered a reversible relation between shear parameters and the creep settlement in floating stone columns; while, in case of end-bearing stone columns shows a direct positive relation between shear parameters and the creep settlement, and the creep settlement began at the primary settlement. The shear parameters affected the improvement factor (n) of creep settlement in both floating and end-bearing stone columns. The standard creep coefficient’s n values in floating and end-bearing conditions were more significant than the low creep coefficient’s n values in forwarded geometric conditions. The stress in both floating and end-bearing stone columns was increasing and uniformly distributed along the length of the floating stone column and in the case of end-bearing stone column was limited to the stiffness layer; the maximum vertical stress was in the central point of the embankment. The embankment’s maximum horizontal displacement occurred on the edge.


Author(s):  
Latif Ahmad ◽  
Saleem Javed ◽  
Muhammad Ijaz Khan ◽  
M. Riaz Khan ◽  
Essam Roshdy El-Zahar ◽  
...  

Particular non-axisymmetric Homann stagnation point flow of Walter’s B fluid over a vertical cylindrical disk is considered in this work. Important physical aspects of newly transient state problem are described by incorporating the effects of magnetic field and mixed convection. Additionally, the temperature and solute concentration are expressed with new parameters in the form of Brownian motion, thermophoretic force, thermal radiation, and 1st order chemical reaction. Furthermore, the problem is modeled with non-linear PDE’s, and which are further converted into ODE’s along with the proposed geometric conditions. Exploration of new physical impacts are described in the form of velocity, temperature, concentration, and displacement thicknesses by applying numerical scheme. However, the momentum equation subjected to the insufficient boundary conditions converting us to apply perturbation technique to reduce the order of ODE accordingly. It is conducted that displacement thicknesses [Formula: see text] and [Formula: see text] tends to its asymptotic value, as [Formula: see text] On the other hand, the displacement thickness [Formula: see text] is found in reverse trends, for the same escalating values of viscoelastic parameter. The skin friction [Formula: see text] variation against viscoelastic parameter is noticed with uplifting trend when [Formula: see text] and vice versa, for [Formula: see text] Outcomes for the Nusselt and Sherwood numbers and rate of heat and mass transfer have been obtained and discussed for parametric variations of the buoyancy parameter ξ, magnetic parameter M, temperature ratio parameter, Brownian motion parameter [Formula: see text], thermophoresis parameter [Formula: see text] and 1st order chemical reaction Rc. Also, shows relative growth for the momentum and concentration profiles.


Author(s):  
Yurong Sun ◽  
Yuxin Du ◽  
Zhifeng Yao ◽  
Qiang Zhong ◽  
Siyuan Geng ◽  
...  

Abstract The objective of this paper is to reveal the influence of different surface geometric conditions on the dynamic behavior characteristics of a laser-induced bubble collapse. A high-speed camera system was used to record the oscillation process of the laser-induced bubble on plane solid walls with different roughness and a wall containing reentrant cavities full of water or gas. The focus is on the quantitative analysis of the morphological characteristics of the cavitation bubble near the solid wall under different surface forms during the first two oscillation period. The results show that the dimensionless ratio γ, defined as the distance from the center of the bubble to the wall divided by the maximum radius of the bubble, has a great influence on the change of the cavitation shape in the direction of the vertical wall. Different surface geometries without gas in our cases have no significant effect on the collapse time of cavitation bubbles. While for the surface containing gas, the direction of movement of the bubble accompanying the micro-jet will greatly change during the collapse of the cavitation bubble, and the collapse time seems to be independent of the dimensionless ratio γ. These achievements shed the light for the engineering to avoid the damage of the micro-jet caused by design suitable surface geometry.


Author(s):  
M. Pirzad ◽  
M. H. Pourmohammadi ◽  
H. Ghorbanizadeh Kharazi ◽  
M. Solimani Babarsad ◽  
E. Derikvand

Abstract Unlike conventional impermeable weirs, porous weirs without clogging the flow and passage of aquatic life with increased aeration and aerobic reactions with minimal negative effects on the environment are known as environmentally friendly structures. This study experimentally investigates the hydraulic performance of Arced-Plan Porous Weirs (APPWs) in different hydraulic and geometric conditions. For this purpose, four different porous and two solid weirs were examined. Experiments were conducted in a horizontal laboratory flume with length, width, and height of 20, 0.6, and 0.5 m, respectively, for a wide range of flow rates, particle sizes, and three arc lengths. Results showed that increasing filling material sizes increases the free discharge coefficient and reduces the submerged Discharge Reduction Factor (DRF). It was also concluded that the weirs’ effective length significantly impacts the free discharge coefficient and has no significant effect on the threshold submergence index and submerged DRF. Unlike solid weirs, the threshold submergence of porous weirs occurs at a downstream depth lower than the weir's height. Finally, according to the dimensional analysis and Gene-Expression Programming (GEP) approach, three relations were extracted to calculate the free discharge coefficient, threshold submergence index, and submerged discharge reduction factor for APPWs.


2021 ◽  
Vol 15 (1) ◽  
pp. 226-240
Author(s):  
Anastasia C. Sutandi

Background: Public buses are a major transportation mode in large cities in the developing country Indonesia. Nevertheless, most societies still use passenger cars. Therefore, the road authority has developed an important policy to improve public bus services soon. One of the public bus services is to change the bus operational system, including the manual ticketing system to an electronic ticket (e-ticket) system. In order to make the policy succeed, the road authority should ask for passengers’ opinions. Objective: The purposes of this study are to ensure that the bus e-ticket is needed to support the policy and then to determine important priority factors of bus e-ticket implementation. Methods: The data were collected using a direct survey with a questionnaire in large cities, Surabaya and Denpasar in Indonesia. A total of 565 bus passengers participated in this survey. An analysis was conducted through cross tabulation between the respondents’ demographic data and their perceived level of need and priority of implementation with regard to various factors of the e-ticket system. The Simple Additive Weighting method was used to determine the important priority factors. Results: Results indicated that a bus e-ticket needed for the cross tabulation average value is more than 3.60 out of 5.00 for all factors. Furthermore, the three highest values of factors based on the Simple Additive Weighting method are ease of access, availability of the bus routes information, and affordability of the e-ticket price. Conclusion: Since respondents indicate that the e-ticket is needed and is a priority, then the policy is beneficial not only to improve bus services in Indonesia but also in other developing countries with similar traffic and geometric conditions.


Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Julio Cesar Avila ◽  
Montserrat Corbera ◽  
Martín Eduardo Frías–Armenta

In this paper, we give the algebraic conditions that a configuration of 5 points in the plane must satisfy in order to be the configuration of zeros of a polynomial isochronous vector field. We use the obtained results to analyze configurations having some of its zeros satisfying some particular geometric conditions.


Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2883
Author(s):  
Suying Liu ◽  
Feng Liu

Let G be an infinite connected graph. We introduce two kinds of multilinear fractional maximal operators on G. By assuming that the graph G satisfies certain geometric conditions, we establish the bounds for the above operators on the endpoint Sobolev spaces and Hajłasz–Sobolev spaces on G.


2021 ◽  
Author(s):  
Behzad Ghiasi ◽  
Sun Yuanbin ◽  
Roohollah Noori ◽  
Hossein Sheikhian ◽  
Amin Zeynolabedin ◽  
...  

Abstract Discharge of pollution loads into natural water systems remains a global challenge that threatens water/food supply as well as endangers ecosystem services. Natural rehabilitation of the polluted streams is mainly influenced by the rate of longitudinal dispersion (Dx), a key parameter with large temporal and spatial fluctuates that characterizes pollution transport. The large uncertainty in estimation of Dx in streams limits evaluation of water quality in natural streams and design of water quality enhancement strategies. This study develops a sophisticated model coupled with granular computing and neural network models (GrC-ANN) to provide robust prediction of Dx and its uncertainty for different flow-geometric conditions with high spatiotemporal variability. Uncertainty analysis of Dx GrC-ANN model was based on the alteration of training data fed to tune the model. Modified bootstrap method was employed to generate different training patterns through resampling from a 503 global database of tracer experiments in streams. Comparison between the Dx values estimated by GrC-ANN to those determined from tracer measurements show the appropriateness and robustness of the proposed method in determining the rate of longitudinal dispersion. GrC-ANN model with the narrowest bandwidth of estimated uncertainty (bandwidth-factor =0.56) that brackets the most percentage of true Dx data (i.e., 100%) is the best model to compute Dx in streams. Given considerable inherent uncertainty reported in other Dx models, the Dx GrC-ANN model is suggested as a proper tool for further studies of pollutant mixing in turbulent flow systems such as streams.


2021 ◽  
Vol 58 ◽  
pp. 18-47
Author(s):  
L.I. Danilov

We prove absolute continuity of the spectrum of a periodic $n$-dimensional Schrödinger operator for $n\geqslant 4$. Certain conditions on the magnetic potential $A$ and the electric potential $V+\sum f_j\delta_{S_j}$ are supposed to be fulfilled. In particular, we can assume that the following conditions are satisfied. (1) The magnetic potential $A\colon{\mathbb{R}}^n\to{\mathbb{R}}^n$ either has an absolutely convergent Fourier series or belongs to the space $H^q_{\mathrm{loc}}({\mathbb{R}}^n;{\mathbb{R}}^n)$, $2q>n-1$, or to the space $C({\mathbb{R}}^n;{\mathbb{R}}^n)\cap H^q_{\mathrm{loc}}({\mathbb{R}}^n;{\mathbb{R}}^n)$, $2q>n-2$. (2) The function $V\colon{\mathbb{R}}^n\to\mathbb{R}$ belongs to Morrey space ${\mathfrak{L}}^{2,p}$, $p\in \big(\frac{n-1}{2},\frac{n}{2}\big]$, of periodic functions (with a given period lattice), and $$\lim\limits_{\tau\to+0}\sup\limits_{0<r\leqslant\tau}\sup\limits_{x\in{\mathbb{R}}^n}r^2\bigg(\big(v(B^n_r)\big)^{-1}\int_{B^n_r(x)}|{\mathcal{V}}(y)|^pdy\bigg)^{1/p}\leqslant C,$$ where $B^n_r(x)$ is a closed ball of radius $r>0$ centered at a point $x\in{\mathbb{R}}^n$, $B^n_r=B^n_r(0)$, $v(B^n_r)$ is volume of the ball $B^n_r$, $C=C(n,p;A)>0$. (3) $\delta_{S_j}$ are $\delta$-functions concentrated on (piecewise) $C^1$-smooth periodic hypersurfaces $S_j$, $f_j\in L^p_{\mathrm{loc}}(S_j)$, $j=1,\ldots,m$. Some additional geometric conditions are imposed on the hypersurfaces $S_j$, and these conditions determine the choice of numbers $p\geqslant n-1$. In particular, let hypersurfaces $S_j$ be $C^2$-smooth, the unit vector $e$ be arbitrarily taken from some dense set of the unit sphere $S^{n-1}$ dependent on the magnetic potential $A$, and the normal curvature of the hypersurfaces $S_j$ in the direction of the unit vector $e$ be nonzero at all points of tangency of the hypersurfaces $S_j$ and the lines $\{x_0+te\colon t\in\mathbb{R}\}$, $x_0\in{\mathbb{R}}^n$. Then we can choose the number $p>\frac{3n}{2}-3$, $n\geqslant 4$.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Di Lei ◽  
Sae-Hoon Kim

The development of 3D modeling technology has promoted the development of the multimedia film and television industry. This article is aimed at studying the design of 3D modeling facial image library in multimedia film and television, at providing a more comprehensive facial image library for the multimedia film and television industry, at breaking the shackles of the traditional film and television industry with 3D technology, and at continuously surpassing traditional film and television media forms. This article deeply explores the background development of multimedia film and television and the characteristics of the development of new media. Starting from 3D technology, it extracts facial features of characters, transforms image data through deep autoencoders, and uses local binarization mode to perform the original facial image is subjected to texture feature extraction. In this paper, a number of experimental subjects were selected, and the subjects were photographed from the left, front, and right from multiple angles. Through the pinhole camera projection imaging process, the internal and external parameters of the camera were adjusted. In the process of 3D image construction, the image is first selected for feature detection, then the corresponding vector information and geometric conditions are matched to construct a 3D matrix, and the facial structure image is obtained by triangulation. This article compares the 3D production software on the market and selects the Maya platform suitable for building this system. The global constraint information is obtained by training some sample images. When searching the test image, find the appropriate feature point position according to the structural matching degree of the local image. When each search is completed, the global information will be used for constraint, so as to output reasonable feature information. The average residual range of the human face image constructed in this paper is 0.25-0.45, and the maximum residual error does not exceed 4.0. The experimental method in this paper has good stability and robustness. Using the COM transmission model can make experimenters not need to think too much about the underlying details. This face animation-driven simulation scheme can achieve more vivid facial expressions.


Sign in / Sign up

Export Citation Format

Share Document