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  • Open Access

    ARTICLE

    Effects of precipitation changes on the dynamics of sparse elm woodland in Northeastern China

    Yi TANG1,*, Carlos Alberto BUSSO2

    BIOCELL, Vol.42, No.2, pp. 61-66, 2018, DOI:10.32604/biocell.2018.07015

    Abstract Elm (Ulmus pumila L.) is the dominant tree species in the sparse elm woodland, the original vegetation in the Horqin Sandy Land. The effects of changes in precipitation on U. pumila trees have not been fully studied. We determined a dynamic model by considering the five stages in the U. pumila life cycle, i.e. seed, seedling, and juvenile, mature and over-mature tree stages. The effects of changes in precipitation on population density and age structure were then evaluated. Population density, after averaging all study developmental morphology stages, ranged from 16.67 individuals/m2 to 25.01 individuals/m2 under a mean annual precipitation (MAP)… More >

  • Open Access

    ARTICLE

    Evolved Algorithm and Vibration Stability for Nonlinear Disturbed Security Systems

    Tcw Chen1, Wray Marriott2, Ann Nicholson3, Tim Chen4, Mars Kmieckowiak5, Jcy Chen6,*

    Sound & Vibration, Vol.53, No.2, pp. 29-37, 2019, DOI:10.32604/sv.2019.04224

    Abstract In this paper, a method sustaining system stability after decomposition is proposed. Based on the stability criterion derived from the energy function, a set of intelligent controllers is synthesized which is used to maintain the stability of the system. The sustainable stability problem can be reformulated as a Linear Matrix Inequalities (LMI) problem. The key to guaranteeing the stability of the system as a whole is to find a common symmetrically positive definite matrix for all subsystems. Furthermore, the Evolved Bat Algorithm (EBA) is employed to replace the pole assignment method and the conventional mathematical methods for solving the LMI.… More >

  • Open Access

    ARTICLE

    Longitudinal Vibration Analysis of Elastically Coupled Nanorods System with General Boundary Supports

    Deshui Xu, Jingtao Du*, Yuhao Zhao

    Sound & Vibration, Vol.53, No.2, pp. 16-28, 2019, DOI:10.32604/sv.2019.04033

    Abstract In this paper, an accurate series solution for the longitudinal vibration analysis of elastically coupled nanorods system is established, in which artificial springs are introduced to simulate such general coupling and boundary conditions. Energy formulation is derived for the description of axial dynamics of multiple coupled nanorods based on Eringen nonlocal elasticity. For each nanorod component, its longitudinal vibration displacement function is invariantly assumed as the superposition of Fourier series and boundary smoothed supplementary polynomials, with the aim to make all the spatial differential sufficiently continuous across each rod. All the unknown coefficients are determined in conjunction with Rayleigh-Ritz procedure… More >

  • Open Access

    ARTICLE

    System Optimization for the Development of Ultrasensitive Electronic Biosensors Using Carbon Nanotube Nanoelectrode Arrays

    Jessica E. Koehne, Jun Li1, Alan M. Cassell, Hua Chen, Qi Ye, Jie Han, M. Meyyappan

    Molecular & Cellular Biomechanics, Vol.1, No.1, pp. 69-80, 2004, DOI:10.3970/mcb.2004.001.069

    Abstract Vertically aligned multi-walled carbon nanotubes (MWCNTs) have been reported in fabricating nanoelectrode arrays. Further studies on optimizing this system for the development of ultrasensitive DNA sensors are reported here. The mechanical stability of the as-grown MWCNT array can be improved by polymer coating or SiO2 encapsulation. The latter method provides excellent electronic and ionic insulation to the sidewall of MWCNTs and the underlying metal layer, which is investigated with electrochemical impedance spectroscopy. The insulation ensures well-defined nanoelectrode behavior. A method is developed for selectively functionalizing biomolecules at the open end of MWCNTs while keeping the SiO2 surface passivated, using the… More >

  • Open Access

    ARTICLE

    Flaw tolerant bulk and surface nanostructures of biological systems

    Huajian Gao1,1, Baohua Ji1,1, Markus J. Buehler1,1, Haimin Yao1,1

    Molecular & Cellular Biomechanics, Vol.1, No.1, pp. 37-52, 2004, DOI:10.3970/mcb.2004.001.037

    Abstract Bone-like biological materials have achieved superior mechanical properties through hierarchical composite structures of mineral and protein. Gecko and many insects have evolved hierarchical surface structures to achieve extraordinary adhesion capabilities. We show that the nanometer scale plays a key role in allowing these biological systems to achieve their superior properties. We suggest that the principle of flaw tolerance may have had an overarching influence on the evolution of the bulk nanostructure of bone-like materials and the surface nanostructure of gecko-like animal species. We demonstrate that the nanoscale sizes allow the mineral nanoparticles in bone to achieve optimum fracture strength and… More >

  • Open Access

    ARTICLE

    Cultivated Land Monitoring System Based on Dynamic Wake-Up UAV and Wireless of Distributed Storage

    Longqing Zhang1, Liping Bai1,*, Xinwei Zhang2, Yanghong Zhang2, Lei Yang1, Xiangdu Yan2

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 817-828, 2019, DOI:10.32604/cmc.2019.06062

    Abstract The drawbacks of the traditional multi-hop structure of wireless sensor networks (WSNS) are susceptible to reflection, scattering and diffraction, serious attenuation of signal intensity and phase deviation due to various obstacles in cultivated land environment and mountains. In this paper, the wireless signal intensity is measured and curve fitting is done respectively in both open environment and obstacle-environment with both sending and receiving height of 0 m, 1 m, and 2 m. It is found out that packet loss probability is too high when an obstacle exists. In such a case, unmanned aerial vehicle (UAV) is introduced to activate terrestrial… More >

  • Open Access

    ARTICLE

    Cryptanalysis and Improvement of a Chaotic Map-Control-Based and the Plain Image-Related Cryptosystem

    Bin Lu1, Fenlin Liu1, Xin Ge1,*, Zhenyu Li2

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 687-699, 2019, DOI:10.32604/cmc.2019.05633

    Abstract Due to the characteristics of chaotic systems, different cryptosystems based on chaos have been proposed to satisfy the security of multimedia data. A plain image-related chaotic algorithm is proposed by Luo et al. with high speed and efficiency. Security weaknesses of the cryptosystem are studied in this paper. It is found that the important secret key information is leaked because an important parameter can be obtained after an inverse operation in the last step of the cryptosystems without secret key. Meanwhile, the value zero is processed improperly in quantification algorithm. Based on the weaknesses, chosen plaintext attack on the cryptosystem… More >

  • Open Access

    ARTICLE

    Research on Architecture of Risk Assessment System Based on Block Chain

    Yang Zhao1, Shibin Zhang1,*, Min Yang1, Peilin He1, Qirun Wang2

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 677-686, 2019, DOI:10.32604/cmc.2019.05936

    Abstract The risk assessment system has been applied to the information security, energy, medical and other industries. Through the risk assessment system, it is possible to quantify the possibility of the impact or loss caused by an event before or after an event, thereby avoiding the risk or reducing the loss. However, the existing risk assessment system architecture is mostly a centralized architecture, which could lead to problems such as data leakage, tampering, and central cheating. Combined with the technology of block chain, which has the characteristics of decentralization, security and credibility, collective maintenance, and untamperability. This paper proposes a new… More >

  • Open Access

    ARTICLE

    A New Time-Aware Collaborative Filtering Intelligent Recommendation System

    Weijin Jiang1,2,3, Jiahui Chen1,*, Yirong Jiang4,*, Yuhui Xu1, Yang Wang1, Lina Tan1, Guo Liang5

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 849-859, 2019, DOI:10.32604/cmc.2019.05932

    Abstract Aiming at the problem that the traditional collaborative filtering recommendation algorithm does not fully consider the influence of correlation between projects on recommendation accuracy, this paper introduces project attribute fuzzy matrix, measures the project relevance through fuzzy clustering method, and classifies all project attributes. Then, the weight of the project relevance is introduced in the user similarity calculation, so that the nearest neighbor search is more accurate. In the prediction scoring section, considering the change of user interest with time, it is proposed to use the time weighting function to improve the influence of the time effect of the evaluation,… More >

  • Open Access

    ARTICLE

    Dynamics of the Moving Ring Load Acting in the System “Hollow Cylinder + Surrounding Medium” with Inhomogeneous Initial Stresses

    Surkay D. Akbarov1,2, Emin T. Bagirov2, Muslum Ozisik3,*

    CMC-Computers, Materials & Continua, Vol.61, No.2, pp. 503-534, 2019, DOI:10.32604/cmc.2019.07561

    Abstract This paper studies the influence of the inhomogeneous initial stress state in the system consisting of a hollow cylinder and surrounding elastic medium on the dynamics of the moving ring load acting in the interior of the cylinder. It is assumed that in the initial state the system is compressed by uniformly distributed normal forces acting at infinity in the radial inward direction and as a result of this compression the inhomogeneous initial stresses appear in the system. After appearance of the initial stresses, the interior of the hollow cylinder is loaded by the moving ring load and so it… More >

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