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Voronoi Based Discrete Least Squares Meshless Method for Heat Conduction Simulation in Highly Irregular Geometries

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Chinese Journal of Mechanical Engineering 2016年第1期29卷 98-111页

作者： LABIBZADEH Mojtaba assistant professor of Structural Engineering Civil Engineering DepartmentFaculty of EngineeringShahid Chamran University

A new technique is used in Discrete Least Square Meshfree（DLSM） method to remove the common existing deficiencies of meshfree methods in handling of the problems containing cracks or concave boundaries. An enhanced Discrete Least Squares Meshless method named as VDLSM（Voronoi based Discrete Least Squares Meshless） is developed in order to solve the steady-state heat conduction problem in irregular solid domains including concave boundaries or cracks. Existing meshless methods cannot estimate precisely the required unknowns in the vicinity of the above mentioned boundaries. Conducted researches are limited to domains with regular convex boundaries. To this end, the advantages of the Voronoi tessellation algorithm are implemented. The support domains of the sampling points are determined using a Voronoi tessellation algorithm. For the weight functions, a cubic spline polynomial is used based on a normalized distance variable which can provide a high degree of smoothness near those mentioned above discontinuities. Finally, Moving Least Squares（MLS） shape functions are constructed using a varitional method. This straight-forward scheme can properly estimate the unknowns（in this particular study, the temperatures at the nodal points） near and on the crack faces, crack tip or concave boundaries without need to extra backward corrective procedures, i.e. the iterative calculations for modifying the shape functions of the nodes located near or on these types of the complex boundaries. The accuracy and efficiency of the presented method are investigated by analyzing four particular examples. Obtained results from VDLSM are compared with the available analytical results or with the results of the well-known Finite Elements Method（FEM） when an analytical solution is not available. By comparisons, it is revealed that the proposed technique gives high accuracy for the solution of the steady-state heat conduction problems within cracked domains or domains with concave boundaries a

关键词： Discrete Least Squares Meshless crack Voronoi tessellation concave boundaries Steady-state heat conduction.

Key networks to create disaster resilient Smart Cities Mission: A case for remodeling India’s Smart Cities Mission to include disaster resilience

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Resilient Cities and Structures

Resilient Cities and Structures 2024年第4期3卷 52-62页

作者： Yamini Meduri R.Singh Geetha Manoharan assistant professor ICFAI Business SchoolICFAI Foundation for Higher EducationIndia Research Scholar SR UniversityIndia assistant professor School of BusinessSR UniversityIndia

Amidst a concerning surge in urban losses attributed to disasters,this research paper explores the intricate relationship between urban development,disaster mitigation,and resilience emphasizing the significance of addressing disaster vulnerability in urban settings,where a substantial portion of the population faces risks stemming from high population density,limited resilience,and inadequate coping *** study advocates for the integration of disaster resilience principles into the Smart Cities Mission of India,placing particular emphasis on the necessity of developing infrastructure,establishing early warning systems,and fostering community engagement to bolster urban ***,the paper draws comparisons and parallels between the components of smart cities,mitigation strategies,and disaster resilience,illuminating their interconnectedness and potential *** conclusion,the study recommends the incorporation of essential network elements to establish a Smart Cities Mission that is resilient to disasters,ultimately aiming to safeguard urban communities from the adverse impacts of future calamities.

关键词： Disaster resilience Smart city mission Disaster mitigation Disaster management

Prediction of Compressive Strength of Various SCC Mixes Using Relevance Vector Machine

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Computers, Materials & Continua 2018年第1期54卷 83-102页

作者： G.Jayaprakash M.P.Muthuraj assistant professor Dept.Civil Engg.KGISL Institute of TechnologyCoimbatore-641035India assistant professor Dept.Civil Engg.Coimbatore Institute of TechnologyCoimbatore-641014 India

This paper discusses the applicability of relevance vector machine(RVM)based regression to predict the compressive strength of various self compacting concrete(SCC)*** strength data various SCC mixes has been consolidated by considering the effect of water cement ratio,water binder ratio and steel *** vector machine(RVM)is a machine learning technique that uses Bayesian inference to obtain parsimonious solutions for regression and *** RVM has an identical functional form to the support vector machine,but provides probabilistic classification and *** is based on a Bayesian formulation of a linear model with an appropriate prior that results in a sparse *** strength model has been developed by using MATLAB software for training and *** 75%of the data has been used for development of model and 30%of the data is used for *** predicted compressive strength for SCC mixes is found to be in very good agreement with those of the corresponding experimental observations available in the literature.

关键词： Relevance Vector Machine Self-compacting concrete Compressive strength Variance

Persisting challenges for performance-based building assessment

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Earthquake Engineering and Engineering Vibration 2014年第S1期13卷 79-94页

作者： B.Bayhan I.Kazaz P.Gulkan Dept.of Civil Engineering Bursa Technical University assistant professor Dept.of Civil Engineering Erzurum Technical University Associate professor Dept.of Civil Engineering Cankaya University professor

Intense research and refinement of the tools used in performance-based seismic engineering have been made,but the maturity and accuracy of these methods have not been adequately confirmed with actual data from the field. The gap between the assumed characteristics of actual building systems and their idealized counterparts used for analysis is wide. When the randomly distributed flaws in buildings as they exist in urban areas and the extreme variability of ground motion patterns combine,the conventional procedures used for pushover or dynamic response history analyses seem to fall short of reconciling the differences between calculated and observed damage. For emergency planning and loss modeling purposes,such discrepancies are factors that must be borne in mind. Two relevant examples are provided herein. These examples demonstrate that consensus-based analytical guidelines also require well-idealized building models that do not lend themselves to reasonably manageable representations from field data. As a corollary,loss modeling techniques,e.g.,used for insurance purposes,must undergo further development and improvement.

关键词： reinforced concrete building nonlinear analysis performance-based seismic assessment performance limits damage

Recent Advancements in the Development of Self Healing Concrete-A Systematic Review

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Journal of Wuhan University of Technology(Materials Science) 2024年第6期39卷 1449-1460页

作者： A Ravi Theja M Srinivasula Reddy Bharat Bhushan Jindal C Sashidhar assistant professor in SVR Engineering College NandyalAndhra PradeshIndia Associate professor of Civil Engineering G Pulla Reddy Engineering CollegeKurnoolAPIndia assistant professor in School of Civil Engineering Shri Mata Vaishno Devi UniversityJammu and KashmirIndia professor of Civil Engineering JNTU College of EngineeringJNTUAAnanthapuramuAndhra PradeshIndia

Mechanical as well as durability properties are pivotal for any type of concrete which gets adversely affected due to cracks that may form due to loading beyond its *** has the intrinsic property to heal itself to some extent but not fully as the passive form of autogenous healing plays an inferior role for a complete repair of a cementitious *** self-healing capabilities can be enhanced by adding chemical admixtures,polymers,and bacteria strains induced calcium carbonate precipitation,*** this paper,the advancements in the development and performance of self-healing concrete using chemical admixtures,polymers,and bacteria strains are *** systematic review includes the available experimental tests and methodologies investigating self-healing efficiency over the last ***,this review focussed on self-healing materials,the ideology,and opinions of those in the construction field on the direction of self-healing concrete for future *** is yet not possible to predict the most appropriate technique,however,a generalized opinion about the effectiveness of the different approaches has been illustrated.

关键词： self-healing cracks bio-based healing chemical additives-based healing

China and the Global Financial Crisis:Assessing the Impacts and Policy Responses

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China & World Economy 2010年第3期18卷 56-72页

作者： Yan Liang assistant professor Willamette University Salem OR USA

The present paper explores the role of China in the creation of the current global financial crisis and the impacts of the crisis on its economy. It argues against the view that the ＂saving glut＂ in China （along with other Asian emerging economies） played a significant causal role in the crisis. The global financial crisis did not engender much damage in China＇s financial structure, thanks to the relatively closed, bank-centered financial system. However, the impacts on the ＂real＂ side of the Chinese economy were hard felt. Growth and employment have fallen, largely due to the decline in exports and foreign direct investment. The crisis reveals the vulnerability of the export-dependent growth pattern. Policy responses of the Chinese Government, including monetary, fiscal and social policies, have helped to stem the downfall of the economy in the immediate term, but some of the policies have not addressed the structural problems of the Chinese economy and might well aggravate such problems over time. The present paper proposes a tentative reform blueprint to rebalance the economy and to sustain long-term growth.

关键词： export dependency financial crisis saving glut structural imbalances

Probabilistic seismic response and reliability assessment of isolated bridges

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Earthquake Engineering and Engineering Vibration 2005年第1期4卷 95-106页

作者： Giuseppe Carlo Marano Department of Environmental Engineering and Sustainable Development Technical University of BariTarantoItalyAssistantProfessor

Bridge seismic isolation strategy is based on the reduction of shear forcestransmitted from the superstructure to the piers by two means: shifting natural period andearthquake input energy reduction by dissipation concentrated in protection devices. In this paper,a stochastic analysis of a simple isolated bridge model for different bridge and device parametersis conducted to assess the efficiency of this seismic protection strategy. To achieve this aim, asimple nonlinear softening constitutive law is adopted to model a wide range of isolation devices,characterized by only three essential mechanical parameters. As a consequence of the random natureof seismic motion, a probabilistic analysis is carried out and the time modulated Kanai-Tajimistochastic process is adopted to represent the seismic action. The response covariance in the statespace is obtained by solving the Lyapunov equation for a stochastic linearized system. After asensitivity analysis, the failure probability referred to extreme displacement and the mean value ofdissipated energy are assessed by using the introduced stochastic indices of seismic bridgeprotection efficiency. A parametric analysis for protective devices with different mechanicalparameters is developed for a proper selection of parameters of isolation devices under differentsituations.

关键词： bridge seismic isolation stochastic analysis nonlinear softeningconstitutive law reliability assessment

Privacy preserving secure expansive aggregation with malicious node identification in linear wireless sensor networks

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Frontiers of Computer Science 2021年第6期15卷 155-163页

作者： Kaushal SHAH Devesh JINWALA assistant professor Computer EngineeringPandit Deendayal Energy UniversityGandhinagar 382007India professor Computer EngineeringSardar Vallabhbhai National Institute of TechnologySurat 395007India

The Wireless Sensor Networks(WSNs)used for the monitoring applications like pipelines carrying oil,water,and gas;perimeter surveillance;border monitoring;and subway tunnel monitoring form ***,the infrastructure being monitored inherently forms linearity(straight line through the placement of sensor nodes).Therefore,suchWSNs are called linear *** applications are security critical because the data being communicated can be used for malicious *** contemporary research of WSNs data security cannot fit in directly to linear WSN as only by capturing few nodes,the adversary can disrupt the entire service of linear ***,we propose a data aggregation scheme that takes care of privacy,confidentiality,and integrity of *** addition,the scheme is resilient against node capture attack and collusion *** are several schemes detecting the malicious ***,the proposed scheme also provides an identification of malicious nodes with lesser key storage ***,we provide an analysis of communication cost regarding the number of messages being *** the best of our knowledge,the proposed data aggregation scheme is the first lightweight scheme that achieves privacy and verification of data,resistance against node capture and collusion attacks,and malicious node identification in linear WSNs.

关键词： linear wireless sensor networks secure data aggregation privacy malicious node identification

Analytical solutions for dynamic pressures of coupling fluid-solid-porous medium due to P wave incidence

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Earthquake Engineering and Engineering Vibration 2004年第2期3卷 263-271页

作者：王进廷张楚汉金峰 Department of Hydraulic Engineering Tsinghua UniversityBeijing 100084China Assistant Professor Department of Hydraulic Engineering Tsinghua UniversityBeijing 100084China Professor

Wave reflection and refraction in layered media is a topic closely related to seismology,acoustics,geophysics and earthquake *** solutions for wave reflection and refraction coefficients in multi-layered media subjected to P wave incidence from the elastic half-space are derived in terms of displacement *** system is composed of ideal fluid,porous medium,and underlying elastic *** numerical examples,the effects of porous medium and the incident wave angle on the dynamic pressures of ideal fluid are *** results show that the existence of the porous medium,especially in the partially saturated case,may significantly affect the dynamic pressures of the overlying fluid.

关键词： porous medium ideal fluid dynamic pressure elastic half-space layered media P wave reflection refraction