Junfeng Zhao^{1, 2}, Weiming Feng¹, Jianping Yuan^{2, 3, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 149-174, 2020, DOI:10.32604/cmes.2020.07504 - 01 January 2020

Abstract Recent studies of the space debris environment in Low Earth Orbit (LEO) have shown that the critical density of space debris has been reached in certain regions. The Active Debris Removal (ADR) mission, to mitigate the space debris density and stabilize the space debris environment, has been considered as a most effective method. In this paper, a novel two-level optimization strategy for multi-debris removal mission in LEO is proposed, which includes the low-level and high-level optimization process. To improve the overall performance of the multi-debris active removal mission and obtain multiple Pareto-optimal solutions, the ADR… More >

Shichao Ma^{1, 2, *}, Xin Ning^{1, 2, *}, Liang Wang³

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.1, pp. 49-59, 2020, DOI:10.32604/cmes.2020.06911 - 01 January 2020

Abstract Friction systems are a kind of typical non-linear dynamical systems in the actual engineering and often generate abundant dynamics phenomena. Because of non-smooth characteristics, it is difficult to handle these systems by conventional analysis methods directly. At the same time, random perturbation often affects friction systems and makes these systems more complicated. In this context, we investigate the steady-state stochastic responses and stochastic P-bifurcation of friction systems under random excitations in this paper. And in order to retain the non-smooth of friction system, the generalized cell mapping (GCM) method is first used to the original… More >

Shaowei Weng^{1, 2, *}, Yiyun Liu¹, Yunqing Shi³, Bo Ou⁴, Chunyu Zhang⁵, Cuiping Wang⁶

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 157-177, 2020, DOI:10.32604/cmc.2020.05681

Abstract This paper proposes a two-step general framework for reversible data hiding (RDH) schemes with controllable contrast enhancement. The first step aims at preserving visual perception as much as possible on the basis of achieving high embedding capacity (EC), while the second step is used for increasing image contrast. In the second step, some peak-pairs are utilized so that the histogram of pixel values is modified to perform histogram equalization (HE), which would lead to the image contrast enhancement. However, for HE, the utilization of some peak-pairs easily leads to over-enhanced image contrast when a large… More >

Cong Xu^{1, 2}, Zhenqi Sun^{2, 3}, Qi Jia^{2, 3}, Dezheng Zhang^{2, 3}, Yonghong Xie^{2, 3,*}, Alan Yang⁴

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 113-122, 2020, DOI:10.32604/cmc.2020.05239

Abstract With the success of new speech-based human-computer interfaces, there is a great need for effective and friendly dialogue agents that can communicate with people naturally and continuously. However, the lack of personality and consistency is one of critical problems in neural dialogue systems. In this paper, we aim to generate consistent response with fixed profile and background information for building a realistic dialogue system. Based on the encoder-decoder model, we propose a retrieval mechanism to deliver natural and fluent response with proper information from a profile database. Moreover, in order to improve the efficiency of More >

Dimitra Papagianni^{1, 2}, Magd Abdel Wahab^{3, 4, *}

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 79-97, 2020, DOI:10.32604/cmc.2020.07988

Abstract This paper deals with modeling of the phenomenon of fretting fatigue in heterogeneous materials using the multi-scale computational homogenization technique and finite element analysis (FEA). The heterogeneous material for the specimens consists of a single hole model (25% void/cell, 16% void/cell and 10% void/cell) and a four-hole model (25% void/cell). Using a representative volume element (RVE), we try to produce the equivalent homogenized properties and work on a homogeneous specimen for the study of fretting fatigue. Next, the fretting fatigue contact problem is performed for 3 new cases of models that consist of a homogeneous More >

Mohamed Abd El-Aziz^{1, 2}, A. M. Aly^{1, 3, *}

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 37-59, 2020, DOI:10.32604/cmc.2020.08488

Abstract In the present study, the effects of the magnetic field on the entropy generation during fluid flow and heat transfer of a Sisko-fluid over an exponentially stretching surface are considered. The similarity transformations are used to transfer the governing partial differential equations into a set of nonlinear-coupled ordinary differential equations. Runge-Kutta-Fehlberg method is used to solve the governing problem. The effects of magnetic field parameter M, local slip parameter λ, generalized Biot number γ, Sisko fluid material parameter A, Eckert number Ec, Prandtl number Pr and Brinkman number Br at two values of power law index on… More >

Ayse Ekin Kara¹, Gurhan Guney^1,2, Aytekin Tokmak¹, Gulnur Ozaksit¹

European Cytokine Network, Vol.30, No.1, pp. 29-33, 2019, DOI:10.1684/ecn.2019.0423

Abstract Objective: The aim of our study was to evaluate serum high-sensitivity C-Reactive Protein (hs-CRP), sialic acid (SA), and interleukin-6 (IL-6) levels in pregnancies complicated with preeclampsia (PE) and intrauterine growth restriction (IUGR) and to compare with healthy pregnancies. Materials and Methods: This study was conducted at a tertiary-level maternity hospital with 80 pregnant women. Fasting blood samples were taken from 44 consecutive women with pregnancies complicated by PE (n: 20) and IUGR (n: 24), and 36 were from normal pregnancies. Serum hs-CRP, SA, and IL-6 concentrations were measured in all participants. Results: Serum mean hs-CRP,… More >

Dewei Wang¹, Tianyang Gao², Yingwei Zhao¹, Ye Mao¹, Zhigang Sheng¹, Qing Lan¹

European Cytokine Network, Vol.30, No.2, pp. 59-66, 2019, DOI:10.1684/ ecn.2019.0426

Abstract Background: Recent studies have demonstrated that nicotine exhibited anti-inflammatory and neuroprotective properties by interacting with the alpha 7 nicotinic acetylcholine receptor (α7nAChR). However, the role of nicotine in regeneration during peripheral nerve injury has not been elucidated. The aim of this study was to investigate whether nicotine down-regulated production of proinflammatory cytokines and promoted peripheral nerve regeneration in rats. Methods: Rats challenged with sciatic nerve crush injury were treated with nicotine (1.5 mg/kg), three times per day. The expression of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin (IL-1β), pinch test results, growth-associated… More >

Nazanin Chatrabnous¹, Abdollah Jafarzadeh^1,2, Abass Ghaderi^3,4, Ali Ariafar⁵, Najmeh Aminizadeh⁶, Farzaneh Ghassabi⁷, Maryam Nemati^2,8

European Cytokine Network, Vol.30, No.4, pp. 144-150, 2019, DOI:10.1684/ ecn.2019.0438

Abstract Background: Inflammation has a prominent role in cancer development and interleukin (IL)-33 has both inflammatory and anti-inflammatory properties. The aim of this study was to measure IL-33 quantities and genetic alterations in the rs1929992 SNP within IL-33 gene in patients with prostate cancer (PC). Methods: This investigation was conducted on blood specimens from 150 newly diagnosed PC patients and 150 healthy age-matched controls. Serum IL-33 measurements and genotyping were performed by ELISA and PCR-RFLP, respectively. Results: Elevated IL-33 quantities were detected in PC patients compared with controls (P < 0.001). The PC patients with Gleason… More >

Hussein M. Jassim, Farooq H. Ali^* , Qusay R. Al-Amir, Hameed K. Hamzah, Salwan Obaid Waheed Khafaji

Frontiers in Heat and Mass Transfer, Vol.12, pp. 1-9, 2019, DOI:10.5098/hmt.12.22

Abstract This study is focused on the entropy generation of laminar natural convection inside a sinusoidal enclosure filled with air (Pr=0.71). The numerical investigation is performed for three shapes of inner cylinders (circle, square, and equilateral triangle) with the same area and different values of the Rayleigh number (10³-10⁶). Galerkin Finite Element Approach is utilized to solve the governing equations. The results showed that the entropy generations due to heat transfer, fluid friction and total entropy generation increase with increasing values of Rayleigh number, while the local Bejan number decreases. More >