D. H. Pahr¹, H.J. Böhm¹

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.2, pp. 117-136, 2008, DOI:10.3970/cmes.2008.034.117

Abstract The combination of heterogeneous volume elements and numerical analysis schemes such as the Finite Element method provides a powerful and well proven tool for studying the mechanical behavior of composite materials. Periodicity boundary conditions (PBC), homogeneous displacement boundary conditions (KUBC) and homogeneous traction boundary conditions (SUBC) have been widely used in such studies. Recently Pahr and Zysset (2008) proposed a special set of mixed uniform boundary conditions (MUBC) for evaluating the macroscopic elasticity tensor of human trabecular bone. These boundary conditions are not restricted to periodic phase geometries, but were found to give the same predictions as PBC for the… More >

Jae Bong Lee¹, Jai Hak Park¹, Sung Ho Lee², Hong-Deok Kim², Han-Sub Chung²

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.1, pp. 9-16, 2006, DOI:10.3970/cmes.2006.011.009

Abstract The growth of stress corrosion cracks in steam generator tubes is predicted using the Monte Carlo simulation and statistical approaches. The statistical parameters that represent the characteristics of crack growth and crack initiation are derived from in-service inspection (ISI) non-destructive evaluation (NDE) data. Based on the statistical approaches, crack growth models are proposed and applied to predict crack distribution at the end of cycle (EOC). Because in-service inspection (ISI) crack data is different from physical crack data, a simple method for predicting the physical number of cracks from periodic in-service inspection data is proposed in this study. Actual number of… More >

Zhijuan Wang^1,2, Xiaobin Zhao^1,2, Wei Song^1,*, Antai Wang³

CMC-Computers, Materials & Continua, Vol.61, No.1, pp. 213-225, 2019, DOI:10.32604/cmc.2019.05690

Abstract Readability is a fundamental problem in textbooks assessment. For low re-sources languages (LRL), however, little investigation has been done on the readability of textbook. In this paper, we proposed a readability assessment method for Tibetan textbook (a low resource language). We extract features based on the information that are gotten by Tibetan segmentation and named entity recognition. Then, we calculate the correlation of different features using Pearson Correlation Coefficient and select some feature sets to design the readability formula. Fit detection, F test and T test are applied on these selected features to generate a new readability assessment formula. Experiment… More >

Xiangyan Tang¹, Qidong Zheng^1,*, Jieren Cheng^1,2, Victor S. Sheng³, Rui Cao¹, Meizhu Chen¹

CMC-Computers, Materials & Continua, Vol.60, No.3, pp. 1263-1281, 2019, DOI:10.32604/cmc.2019.06173

Abstract The existing network security situation assessment methods cannot effectively assess the Distributed denial-of-service (DDoS) attack situation. In order to solve these problems, we propose a DDoS attack situation assessment method via optimized cloud model based on influence function. Firstly, according to the state change characteristics of the IP addresses which are accessed by new and old user respectively, this paper defines a fusion feature value. Then, based on this value, we establish a V-Support Vector Machines (V-SVM) classification model to analyze network flow for identifying DDoS attacks. Secondly, according to the change of new and old IP addresses, we propose… More >

Kamaljit Kaur^{1, *}, Kuljit Kaur²

CMC-Computers, Materials & Continua, Vol.60, No.3, pp. 913-946, 2019, DOI:10.32604/cmc.2019.07675

Abstract Hard Disk drives (HDDs) are an essential component of cloud computing and big data, responsible for storing humongous volumes of collected data. However, HDD failures pose a huge challenge to big data servers and cloud service providers. Every year, about 10% disk drives used in servers crash at least twice, lead to data loss, recovery cost and lower reliability. Recently, the researchers have used SMART parameters to develop various prediction techniques, however, these methods need to be improved for reliability and real-world usage due to the following factors: they lack the ability to consider the gradual change/deterioration of HDDs; they… More >

Zhaoyue Zhang^{1, *}, Jing Zhang², Peng Wang¹, Lei Chen³

CMC-Computers, Materials & Continua, Vol.57, No.1, pp. 151-166, 2018, DOI:10.32604/cmc.2018.02890

Abstract In order to explore the safe operation of UAVs in non-segregated airspace, a collision risk model for cylindrical UAVs based on conflict areas was constructed and the risk of conflict between manned and unmanned aerial vehicles was researched. According to the results of risk analysis, a strategy for solving the conflict of aircraft is proposed, and the risk assessment experiment of unmanned aerial vehicle (UAV) in non-isolated airspace conflict is carried out. The results show that under the experimental conditions, large unmanned aerial vehicles equipped with ADS-B, TCAS and other airborne sensing systems will indeed interfere with other aircraft in… More >

Subashini I^{1, a}, Smitha Gopinath^{2, *}, Aahrthy R^{3, b}

CMC-Computers, Materials & Continua, Vol.53, No.4, pp. 291-306, 2017, DOI:10.3970/cmc.2017.053.291

Abstract Present paper proposes a methodology by combining finite element method with smoothed particle hydrodynamics to simulate the response of textile reinforced concrete (TRC) slabs under low velocity impact loading. For the constitutive modelling in the finite element method, the concrete damaged plasticity model was employed to the cementitious binder of TRC and Von-Mises criterion was used for the textile reinforcement. Strain dependent smoothed particle hydrodynamics (SPH) was used to assess the damage and failure pattern of TRC slabs. Numerical simulation was carried out on TRC slabs with two different volume fraction of glass textile reinforcement to predict the energy absorption… More >

Marcello Lappa ¹

CMC-Computers, Materials & Continua, Vol.2, No.1, pp. 51-64, 2005, DOI:10.3970/cmc.2005.002.051

Abstract A possible approach for the investigation of a number of aspects related to the processing of immiscible alloys, made possible by recent progress in both fields of moving boundary (VOF) methods and speed of computers, is discussed. It can capture in a single numerical treatment and without limiting assumptions both macroscopic information (i.e. the macrophysical problem, heretofore treated in terms of population dynamics) and microscopic details (i.e. the microphysical problem, heretofore treated within the framework of boundary integral methods and/or under the assumption of nondeformable drops). The role played by coalescence in changing the Marangoni migration velocity is discussed together… More >

R. Gangadharan¹, A. Rajagopal¹, S.M. Sivakumar^{1, 2}

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 229-244, 2004, DOI:10.3970/cmc.2004.001.229

Abstract A new r-h adaptive scheme is proposed and formulated. It involves a combination of the configurational force based r-adaption with weighted Laplacian smoothing and mesh enrichment by h-refinement. A Zienkiewicz-Zhu best guess stress error estimator is used in the h-refinement strategy. The best sequence for combining the effectiveness of r- and h- adaption has been evolved at in this study. A further reduction in the potential energy and the relative error norm of the system is found to be achieved with combined r-adaption and mesh enrichment (in the form h-refinement). Numerical study confirms that the proposed combined r-h adaption is… More >