scholarly journals Design Method of Analog Sigmoid Function and its Approximate Derivative

2021 ◽  
Author(s):  
Lylia Thiziri Chabane ◽  
Dang-Kien Germain Pham ◽  
Paul Chollet ◽  
Patricia Desgreys
Keyword(s):  
Design Method ◽  
Sigmoid Function ◽  
Approximate Derivative

A Design Method of Beads in Shell Structure Using Non-Parametric Shape Optimization Method

2014 ◽  
Author(s):  
Kohei Shintani ◽  
Hideyuki Azegami
Keyword(s):  
Shape Optimization ◽  
Shell Structure ◽  
Parametric Design ◽  
Design Method ◽  
Optimization Method ◽  
Adjoint Problem ◽  
Sigmoid Function ◽  
Out Of Plane ◽  
Mean Compliance ◽  
Non Parametric

The present paper describes a method finding bead shapes in shell structure to increase the stiffness using a solution to shape optimization method. Variation of the shell structure in out-of-plane direction is chosen as a non-parametric design variable. To create beads, the out-of-plane variation is restricted by using the sigmoid function. Mean compliance is used as objective function. The main problem is defined as a linear elastic problem for shell structure. The Fréchet derivative with respect to the out-of-plane variation of the mean compliance is evaluated with the solutions of the main problem and an adjoint problem which is derived theoretically by the adjoint variable method. To solve the bead design problem, an iterative algorithm based on the H1 gradient method is used. Numerical results show the effectiveness of the method.

Development of a New Dynamic Modulus Predictive Model Based on Binder Viscosity for the Superpave Mixtures of New Mexico

2016 ◽  
Author(s):  
A. S. M. Asifur Rahman ◽  
Rafiqul A. Tarefder
Keyword(s):  
New Mexico ◽  
Predictive Model ◽  
Asphalt Concrete ◽  
Dynamic Modulus ◽  
Design Method ◽  
Superposition Principle ◽  
Asphalt Binder ◽  
Accurate Estimation ◽  
Sigmoid Function ◽  
Uniformity Coefficient

The newly developed mechanistic-empirical pavement design method uses the dynamic modulus as one of the crucial input parameters for the asphalt pavement to be designed or analyzed. This study proposes a new regression-based predictive model to estimate dynamic modulus of asphalt concrete from the viscosity of the asphalt binder used in the asphalt-aggregate mixture. Other parameters related to the aggregate gradation, such as, fineness modulus, and uniformity coefficient and the parameters related to the mixture volumetric are also incorporated in this model. A total of 21 asphalt concrete mixtures with asphalt binders having different performance grades and Superpave gradations were collected from different mixing plants and paving sites at various regions of New Mexico. The collected mixtures were then compacted, cored and sawed to cylindrical specimens. The asphalt concrete specimens were then tested for dynamic modulus at different temperatures and loading frequencies. The time-temperature superposition principle was then applied to develop dynamic modulus mastercurves at 70 °F (21.1 °C) reference temperature. The mastercurves were then fitted by the sigmoid function. The parameters of the sigmoid function were then correlated to the physical attributes of the asphalt concrete samples. Finally, a predictive model is developed to estimate the dynamic modulus of the AC mixtures typically used in New Mexico. Statistical evaluation showed that a fairly accurate estimation of dynamic modulus can be found by using this new dynamic modulus predictive model.

Application of a work-centered design method to support counterspace operations

2005 ◽  
Author(s):  
Michael Szczepkowski ◽  
Kelly Neville ◽  
Ed Popp
Keyword(s):  
Design Method

PERANCANGAN SISTEM PEMBELAJARAN MOBILE (M-LEARNING) BERBASIS ANDROID PADA MATERI BANGUN DATAR DAN BANGUN RUANG

2018 ◽  
Vol 1 (2) ◽  
pp. 1-17
Author(s):  
Tedi Budiman
Keyword(s):  
Mobile Learning ◽  
Design Method ◽  
Case Study Method ◽  
Application Development ◽  
Software Application ◽  
Rapid Application Development ◽  
User Design ◽  
Design Software ◽  
Application Programs

One example of the growing information technology today is mobile learning, mobile learning which refers to mobile technology as a learning medium. Mobile learning is learning that is unique for each student to access learning materials anywhere, anytime. Mobile learning is suitable as a model of learning for the students to make it easier to get an understanding of a given subject, such as math is pretty complicated and always using formulas.The design method that I use is the case study method, namely, learning, searching and collecting data related to the study. While the development of engineering design software application programs that will be used by the author is the method of Rapid Application Development (RAD), which consists of 4 stages: Requirements Planning Phase, User Design Phase, Construction Phase and Phase Cotuver.

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