Wan-Sul Lee, Kie-Chan Kwon, Bong-Kyu Kim, Ji-Hyon Cho, Sung-Kie Youn¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.3, pp. 279-286, 2004, DOI:10.3970/cmes.2004.005.279

Abstract A numerical approach for eigenvalue analysis of the electrostatically tunable micro-mechanical actuators is presented. An efficient algorithm for calculating the natural frequency shifting in the micro-mechanical actuators due to applied DC turning voltage is proposed. In the calculations of the coupled field problem, the three-dimensional FEM/BEM approaches and iterative staggered algorithm are employed. The numerical examples for actually fabricated actuators are presented and the numerical analysis results are compared with experimental data. More >

Mengyue He¹, Zhifang Zhang^1,*, Karthik Ram Ramakrishnan²

Structural Durability & Health Monitoring, Vol.12, No.4, pp. 213-256, 2018, DOI:10.32604/sdhm.2018.05122

Abstract Fibre reinforced polymer (FRP) composite laminates are now commonly used in many structural applications, especially in the aerospace industry, where margins of safety are kept low in order to minimise weight. Timely detection and assessment of damage (in particular delaminations) in composite laminates are therefore critical, as they can cause loss of structural integrity affecting the safe operation of the composite structures. The current trend is towards implementation of structural health monitoring (SHM) systems which can monitor the structures in situ without down time. In this paper, first, the current available SHM techniques for delamination detection in FRP composites are… More >

Roshan Kumar^1,*, Wei Zhao¹, Vikash Singh²

Structural Durability & Health Monitoring, Vol.12, No.2, pp. 65-83, 2018, DOI: 10.3970/sdhm.2018.02329

Abstract This paper presents an evaluation of time-frequency methods for the analysis of seismic signals. Background of the present work is to describe, how the frequency content of the signal is changing in time. The theoretical basis of short time Fourier transform, Gabor transform, wavelet transform, S-transform, Wigner distribution, Wigner-Ville distribution, Pseudo Wigner-Ville distribution, Smoothed Pseudo Wigner-Ville distribution, Choi-William distribution, Born-Jordan Distribution and cone shape distribution are presented. The strengths and weaknesses of each technique are verified by applying them to a particular synthetic seismic signal and recorded real time earthquake data. More >

Wei Huang^∗, Jun Shi^†, R. T. Yen^†,‡

Molecular & Cellular Biomechanics, Vol.9, No.4, pp. 269-284, 2012, DOI:10.3970/mcb.2012.009.269

Abstract The objective of our study was to develop a computing program for computing the transit time frequency distributions of red blood cell in human pulmonary circulation, based on our anatomic and elasticity data of blood vessels in human lung. A stochastic simulation model was introduced to simulate blood flow in human pulmonary circulation. In the stochastic simulation model, the connectivity data of pulmonary blood vessels in human lung was converted into a probability matrix. Based on this model, the transit time of red blood cell in human pulmonary circulation and the output blood pressure were studied. Additionally, the stochastic simulation… More >

Q Wang^*, YP Zheng^∗,†, HJ Niu^∗,‡

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 45-58, 2010, DOI:10.3970/mcb.2010.007.045

Abstract This study aims to obtain osmosis-induced swelling strains of normal and proteoglycan (PG) depleted articular cartilage using an ultrasound system and to investigate the changes in its mechanical properties due to the PG depletion using a layered triphasic model. The swelling strains of 20 cylindrical cartilage-bone samples collected from different bovine patellae were induced by decreasing the concentration of bath saline and monitored by the ultrasound system. The samples were subsequently digested by a trypsin solution for approximately 20 min to deplete proteoglycans, and the swelling behaviors of the digested samples were measured again. The bi-layered triphasic model proposed in… More >

Shaohua Hu^*, Ning Wang^†

Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 49-60, 2006, DOI:10.3970/mcb.2006.003.049

Abstract One fundamental question in cell biology is how mechanical stresses are distributed inside the cytoplasm. Recently we have developed a synchronous detection approach to map cytoplasmic displacements and stresses using yellow fluorescent protein tagged mitochondria as fiducial markers of the cytoskeleton (CSK) in response to a localized load applied via an RGD-coated magnetic bead (7). We have shown that stresses are propagated to remote sites in the cytoplasm, a finding that contradicts continuum model predictions. Here we show that long distance force propagation in the cytoplasm was abolished when the contractile prestress in the CSK was lowered by relaxing agents… More >

Y. Zhang^1,2, Z.H. Xiang^1,3

CMC-Computers, Materials & Continua, Vol.26, No.1, pp. 19-36, 2011, DOI:10.3970/cmc.2011.026.019

Abstract Vibration based damage detection methods play an important role in the maintenance of beam structures such as bridges. However, most of them require the accurate measurement of structural mode shapes, which may not be easily satisfied in practice. Since the measurement of frequencies is more accurate than that of mode shapes, this paper proposes a frequency shift curve (FSC) method, based on the equivalence between the FSC due to auxiliary mass and the mode shape square, which has been demonstrated to be effective in structural damage detection. Two damage indices based on the FSC are developed, which are called the… More >

Jae-In Kim¹, Hyoseon Jang², Jeong-Hee Ahn³, Kilho Eom⁴, Sungsoo Na⁵

CMC-Computers, Materials & Continua, Vol.9, No.2, pp. 137-152, 2009, DOI:10.3970/cmc.2009.009.137

Abstract Protein dynamics is essential for gaining insight into biological functions of proteins. Although protein dynamics is well delineated by molecular model, the molecular model is computationally prohibited for simulating large protein structures. In this work, we provide the three-dimensional coarser-grained anisotropic model (CGAM), which is based on model reduction applicable to large protein structures. It is shown that CGAM achieves the fast computation on low-frequency modes, quantitatively comparable to original structural model such as elastic network model (ENM). This indicates that the CGAM by model reduction method enable us to understand the functional motion of large proteins with remarkable computational… More >

Sahib Khan^1,*, M A Irfan¹, Arslan Arif¹, Syed Tahir Hussain Rizvi², Asma Gul³, Muhammad Naeem⁴, Nasir Ahmad⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.3, pp. 529-546, 2019, DOI:10.31614/cmes.2019.06179

Abstract This work presents a new method of data hiding in digital images, in discrete cosine transform domain. The proposed method uses the least significant bits of the medium frequency components of the cover image for hiding the secret information, while the low and high frequency coefficients are kept unaltered. The unaltered low frequency DCT coefficients preserves the quality of the smooth region of the cover image, while no changes in the high DCT coefficient preserve the quality of the edges. As the medium frequency components have less contribution towards energy and image details, so the modification of these coefficients for… More >

Huaxi Lu^1,*, Zhicheng Gao¹, Luyao Xu¹, Bitao Wu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.118, No.1, pp. 177-205, 2019, DOI:10.31614/cmes.2019.04169

Abstract The railway environmental vibration caused by high-speed railways is harmful to the human health, the structural safety of adjacent buildings, and the normal use of precision instruments. At the same time, it occurs frequently. In this case, the railway environmental vibration has drawn much attention with the rapid development of high-speed railways. Studies in Earthquake Engineering show that a convex topography has a great impact on ground vibrations, however, there is no consideration about the convex topographic effect in the study of the railway environmental vibration when the convex topography is near the roadway. In this paper, the influence of… More >