Open Access
ARTICLE
Kazunori Shinohara*
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 441-473, 2020, DOI:10.32604/cmes.2020.08656
Abstract Addition formulas exist in trigonometric functions. Double-angle
and half-angle formulas can be derived from these formulas. Moreover, the
relation equation between the trigonometric function and the hyperbolic function
can be derived using an imaginary number. The inverse hyperbolic function
is similar to the inverse trigonometric function
, such as the second degree of a polynomial and the constant term 1, except for the sign − and +. Such an analogy holds not only when the
degree of the polynomial is 2, but also for higher degrees. As such, a function
exists with respect… More >
Open Access
ARTICLE
M. J. Huntul1, D. Lesnic2, *
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 475-494, 2020, DOI:10.32604/cmes.2020.08791
Abstract In this paper, we consider solving numerically for the first time inverse problems
of determining the time-dependent thermal diffusivity coefficient for a weakly degenerate
heat equation, which vanishes at the initial moment of time, and/or the convection
coefficient along with the temperature for a one-dimensional parabolic equation, from
some additional information about the process (the so-called over-determination
conditions). Although uniquely solvable these inverse problems are still ill-posed since
small changes in the input data can result in enormous changes in the output solution.
The finite difference method with the Crank-Nicolson scheme combined with the
nonlinear Tikhonov regularization are employed. The… More >
Open Access
ARTICLE
Xinglong Wang1,2, Cheng Wang1,2, Xin Zhou1,*, Mingkang Zhang3, Peiyu Zhang1, Lei Wang2
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 495-508, 2020, DOI:10.32604/cmes.2020.09778
（This article belongs to this Special Issue: Design & simulation in Additive Manufacturing)
Abstract The new regenerative cooling thermal protection system exhibits the
multifunctional characteristics of load-carrying and heat exchange cooling, which
are fundamental for the lightweight design and thermal protection of hypersonic
vehicles. Triply periodic minimal surface (TPMS) is especially suitable for the
structural design of the internal cavity of regenerative cooling structures owing
to its excellent structural characteristics. In this study, test pieces were manufactured using Ti6Al4V lightweight material. We designed three types of porous test
pieces, and the interior was filled with a TPMS lattice (Gyroid, Primitive, I-WP)
with a porosity of 30%. All porous test pieces were manufactured via selective… More >
Open Access
ARTICLE
Huawen Shu, Minghai Xu, Xinyue Duan*, Yongtong Li, Yu Sun, Ruitian Li, Peng Ding
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 509-523, 2020, DOI:10.32604/cmes.2020.08806
（This article belongs to this Special Issue: Advances in Modeling and Simulation of Complex Heat Transfer and Fluid Flow)
Abstract A finite volume method based unstructured grid is presented to solve
the two dimensional viscous and incompressible flow. The method is based on
the pressure-correction concept and solved by using a semi-staggered grid technique. The computational procedure can handle cells of arbitrary shapes, although
solutions presented in this paper were only involved with triangular and quadrilateral cells. The pressure or pressure-correction value was stored on the vertex
of cells. The mass conservation equation was discretized on the dual cells surrounding the vertex of primary cells, while the velocity components and other
scale variables were saved on the central of primary… More >
Open Access
ARTICLE
Alireza Poordavoodi1, Mohammad Reza Moazami Goudarzi2,*, Hamid Haj Seyyed Javadi3, Amir Masoud Rahmani4, Mohammad Izadikhah5
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 525-570, 2020, DOI:10.32604/cmes.2020.08854
Abstract With the growing number of Web services on the internet, there is a challenge to
select the best Web service which can offer more quality-of-service (QoS) values at the
lowest price. Another challenge is the uncertainty of QoS values over time due to the
unpredictable nature of the internet. In this paper, we modify the interval data envelopment
analysis (DEA) models [Wang, Greatbanks and Yang (2005)] for QoS-aware Web service
selection considering the uncertainty of QoS attributes in the presence of desirable and
undesirable factors. We conduct a set of experiments using a synthesized dataset to show the
capabilities of… More >
Open Access
ARTICLE
J. Serrano-Arellano1, J. M. Belman-Flores2,*, I. Hernández-Pérez3, K. M. Aguilar-Castro3, E. V. Macías-Melo3, F. Elizalde-Blancas2, J. M. Riesco-Ávila2, F. J. García-Rodríguez4
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 571-602, 2020, DOI:10.32604/cmes.2020.08677
Abstract In the present study, an analysis of the heat and mass transfer in a ventilated
cavity in a warm climate zone was carried out to analyze, among others, the temperatures
and percentage of relative humidity (RH). The governing equations of the mathematical
model were solved through the finite volume method. We used the k-ε turbulence mode
to find the results of the variables of interest in seven climate records on a given day.
The velocity of the inlet flow of the air-H2O mixture was varied through the Reynolds
number (Re) from 500 to 10000. The outdoor weather conditions considered were… More >
Open Access
ARTICLE
Ji Liang1, Zhihuan Chen2,*, Xiaohui Yuan1,3,*, Binqiao Zhang3, Yanbin Yuan4
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 603-629, 2020, DOI:10.32604/cmes.2020.09328
Abstract Terminal sliding mode controller method is introduced to enhance the
regulation performance of the hydraulic turbine governing system (HTGS). For
the purpose of describing the characteristics of controlled system and deducing
the control rule, a nonlinear mathematic model of hydraulic turbine governing
system with bifurcated penstocks (HTGSBF) under control input saturation is
established, and the input/output state linearization feedback approach is used
to obtain the relationship between turbine speed and controller output. To address
the control input saturation problem, an adaptive assistant system is designed to
compensate for controller truncation. Numerical simulations have been conducted
under fixed point stabilization and… More >
Open Access
ARTICLE
Caining Zhang1, Xiaopeng Guo2, Xiaoya Guo3, David Molony4, Huaguang Li2, Habib Samady4, Don P. Giddens4,5, Lambros Athanasiou6, Dalin Tang1*,7, Rencan Nie2,*, Jinde Cao8
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 631-646, 2020, DOI:10.32604/cmes.2020.09718
Abstract Optical coherence tomography (OCT) is a new intravascular imaging
technique with high resolution and could provide accurate morphological information for plaques in coronary arteries. However, its segmentation is still commonly performed manually by experts which is time-consuming. The aim of
this study was to develop automatic techniques to characterize plaque components
and quantify plaque cap thickness using 3 machine learning methods including
convolutional neural network (CNN) with U-Net architecture, CNN with Fully
convolutional DenseNet (FC-DenseNet) architecture and support vector machine
(SVM). In vivo OCT and intravascular ultrasound (IVUS) images were acquired
from two patients at Emory University with informed consent… More >
Open Access
ARTICLE
Jun Chen1, *, Rao Hu2, Xianfeng Guo3, Feng Wu2
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 647-660, 2020, DOI:10.32604/cmes.2020.09180
（This article belongs to this Special Issue: Security Enhancement of Image Recognition System in IoT based Smart Cities)
Abstract Underground pipeline networks constitute a major component of urban
infrastructure, and thus, it is imperative to have an efficient mechanism to manage them.
This study introduces a secondary development system to efficiently model underground
pipeline networks, using the building information modeling (BIM)-based software Revit.
The system comprises separate pipe point and tubulation models. Using a Revit application
programming interface (API), the spatial position and attribute data of the pipe points are
extracted from a pipeline database, and the corresponding tubulation data are extracted
from a tubulation database. Using the Family class in Revit API, the cluster in the self-built
library… More >
Open Access
ARTICLE
Wei Liu1, 2, *, Qianxiang Wu2
CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 661-690, 2020, DOI:10.32604/cmes.2020.07764
（This article belongs to this Special Issue: Numerical Modeling and Simulation for Structural Safety and Disaster Mitigation)
Abstract A utility tunnel system consists of pipes and ancillary facilities. In this paper, a
finite element model of a concrete utility tunnel with pipes inside is established. Several
tunnel segments were built to simulate a real utility tunnel, while the pipe was fixed by
springs on the brackets in the utility tunnel. Using the discrete soil spring element to
simulate the soil-structure interaction, actual earthquake records were adopted as excitation
to analyze the seismic responses of pipes in a utility tunnel. Moreover, the influences of
different parameters, including soil type, earthquake records, and field apparent wave
velocity on the seismic… More >
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