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Inverse Construction Methods of Heterogeneous NURBS Object Based on Additive Manufacturing
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作者 Ting Zang Dongbin Zhu Guowang Mu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第11期597-610,共14页
According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this... According to the requirement of heterogeneous object modeling in additive manufacturing(AM),the Non-Uniform Rational B-Spline(NURBS)method has been applied to the digital representation of heterogeneous object in this paper.By putting forward the NURBS material data structure and establishing heterogeneous NURBS object model,the accurate mathematical unified representation of analytical and free heterogeneous objects have been realized.With the inverse modeling of heterogeneous NURBS objects,the geometry and material distribution can be better designed to meet the actual needs.Radical Basis Function(RBF)method based on global surface reconstruction and the tensor product surface interpolation method are combined to RBF-NURBS inverse construction method.The geometric and/or material information of regular mesh points is obtained by RBF interpolation of scattered data,and the heterogeneous NURBS surface or object model is obtained by tensor product interpolation.The examples have shown that the heterogeneous objects fitting to scattered data points can be generated effectively by the inverse construction methods in this paper and 3D CAD models for additive manufacturing can be provided. 展开更多
关键词 NURBS heterogeneous object inverse construction method RBF scattered data points
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4D Design and Simulation Technologies and Process Design Patterns to Support Lean Construction Methods 被引量:2
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作者 Manfred Breit Manfred Vogel +2 位作者 Fritz Hubi Fabian Mrki Micheal Raps 《Tsinghua Science and Technology》 SCIE EI CAS 2008年第S1期179-184,共6页
The objective of this ongoing joint research program is to determine how 3D/4D modeling, simulation and visualization of Products (buildings), Organizations and Processes (POP) can support lean construction. Initial f... The objective of this ongoing joint research program is to determine how 3D/4D modeling, simulation and visualization of Products (buildings), Organizations and Processes (POP) can support lean construction. Initial findings suggest that Process Design Pattern may have the potential to intuitively support ICT based lean construction. We initiated a 'Process Archeology' in order to reveal the requirements for tools that can support the planning, simulation and control of lean construction methods. First findings show that existing tools provide only limited support and therefore, we started to develop new methodologies and technologies to overcome these shortcomings. Through the introduction of Process Design Patterns, we intent to establish process thinking in the interdisciplinary POP design. Optimized construction processes may be synthesized with semi-automatic methods by applying Process Design Patterns on building structures. By providing process templates that integrate problem solution and expert knowledge, Process Design Patterns may have the potential to ensure high quality process models. 展开更多
关键词 4D design process and organization modeling and simulation process design patterns lean construction methods
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Research on the Reform of the Course“Reading of Concrete Structure Plan and Construction Drawings”Under the Background of“Promoting Teaching and Learning Through Competitions”
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作者 Guixiang Yu Xiaolong Tan 《Journal of Architectural Research and Development》 2023年第4期32-38,共7页
The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the ... The inherent teaching approach can no longer meet the demands of society.In this paper,current issues within the teaching landscape of architectural engineering technology in higher vocational colleges as well as the policies and teaching demands that formed the basis of this model were analyzed.The study shows the importance of the implementation of the teaching model“promoting teaching and learning through competitions.”This model puts emphasis on the curriculum and teaching resources,while also integrating the teaching process and evaluation with competition.These efforts aim to drive education reform in order to better align with the objectives of vocational education personnel training,while also acting as a reference for similar courses. 展开更多
关键词 Promoting teaching through competitions Promoting learning through competitions Reading of concrete structure plan method construction drawings Course reform
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Construction of <i>k</i>-Variate Survival Functions with Emphasis on the Case <i>k</i>= 3
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作者 Jerzy K. Filus Lidia Z. Filus 《Applied Mathematics》 2020年第7期678-697,共20页
The purpose of this paper is to present a general universal formula for <span style="font-family:Verdana;"><i></i></span><i><span><span><i><span style="... The purpose of this paper is to present a general universal formula for <span style="font-family:Verdana;"><i></i></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;">-variate survival functions for arbitrary </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> = 2, 3, </span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;">...</span><span style="font-family:Verdana;">, given all the univariate marginal survival functions. This universal form of </span></span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;">-variate probability distributions was obtained by means of “dependence functions” named “joiners” in the text. These joiners determine all the involved stochastic dependencies between the underlying random variables. However, in order that the presented formula (the form) represents a legitimate survival function, some necessary and sufficient conditions for the joiners had to be found. Basically, finding those conditions is the main task of this paper. This task was successfully performed for the case </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;"> = 2 and the main results for the case </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;"> = 3 were formulated as Theorem 1 and Theorem 2 in Section 4. Nevertheless, the hypothetical conditions valid for the general </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;"> ≥ 4 case were also formulated in Section 3 as the (very convincing) Hypothesis. As for the sufficient conditions for both the </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> = 3 and</span><i> </i></span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;"> ≥ 4 cases, the full generality was not achieved since two restrictions were imposed. Firstly, we limited ourselves to the, defined in the text, “continuous cases” (when the corresponding joint density exists and is continuous), and secondly we consider positive stochastic dependencies only. Nevertheless, the class of the </span><span style="font-family:Verdana;"><i></i></span></span></span><i><span><span><i><span style="font-family:Verdana;">k</span></i><span style="font-family:Verdana;"></span></span></span></i><span><span><span style="font-family:Verdana;">-variate distributions which can be constructed is very wide. The presented method of construction by means of joiners can be considered competitive to the </span><span style="font-family:Verdana;"><strong></strong></span></span></span><strong><span><span><b><span style="font-family:Verdana;">copula</span></b><span style="font-family:Verdana;"></span></span></span></strong><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> methodology. As it is suggested in the paper the possibility of building a common theory of both copulae and joiners is quite possible, and the joiners may play the role of tools within the theory of copulae, and vice versa copulae may, for example, be used for finding proper joiners. Another independent feature of the joiners methodology is the possibility of constructing many new stochastic processes including stationary and Markovian.</span></span></span> 展开更多
关键词 construction of Multivariate Probability Distributions via Joiners Joiner versus Copula Methodology A Possible Fusion of the Two construction methods k -Variate Survival Function Scheme k = 3 Case
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Guide for Barriers when Using Soils and Construction Materials with Environmentally Sensitive Contents
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作者 Kent von Maubeuge Antje Müller-Kirchenbauer Carsten Schlötzer 《Journal of Environmental Science and Engineering(B)》 2022年第4期125-138,共14页
On 16 July 2021,the German“Mantelverordnung”(Construction Materials Regulation)was published in the Federal Law Journal.From August 1,2023,this regulation is to be applied nationwide and,for the first time,regulates... On 16 July 2021,the German“Mantelverordnung”(Construction Materials Regulation)was published in the Federal Law Journal.From August 1,2023,this regulation is to be applied nationwide and,for the first time,regulates legally nationwide binding requirements for mineral construction waste and its use in technical structures.It also refers to specific construction methods with construction waste material.In the course of the construction of infrastructure traffic routes,it is possible to use these construction materials with limited contamination for the construction of,e.g.,noise barriers,dams or embankments.The German M TS E(Merkblattüber Bauweisen für Technische Sicherungsmaßnahmen beim Einsatz von Böden und Baustoffen mit umweltrelevanten Inhaltsstoffen im Erdbau)Guideline of the FGSV(Road and Transportation Research Association)lists various alternatives for barriers in such structures.Geosynthetic barriers,e.g.,GCLs(Geosynthetic Clay Liners,also known as bentonite mats)or polymeric geomembranes as well as other geosynthetics can have economic and design advantages over conventional mineral barriers.Depending on the proposed construction method,the guideline sets out certain requirements,not only but also for permittivity and confining stress.In the following,the construction methods in general and the design solutions with GCLs in particular are presented. 展开更多
关键词 construction waste geosynthetic barriers GCLs barrier construction methods.
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Penalty model for delay of bidding section construction period in South-to-North Water Diversion Eastern Route Project from perspective of programs 被引量:2
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作者 Jing-chun FENG Ya-fang REN +2 位作者 Zhong-nan DUAN Zhan-jun LIU Hai-yang LI 《Water Science and Engineering》 EI CAS 2012年第3期350-360,共11页
According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculatio... According to the multi-project and program management theory, this paper analyzes the program generation principle and establishes a program based on progress goals. On the basis of the present situation of calculation of penalty for delay of the bidding section construction period with the critical path method, we studied the effects of contractor-induced delay of the bidding section construction period in detail, including the effects on the construction period of the bidding section itself, the earliest start times of the next bidding section and other subsequent bidding sections, and the construction period of the program, and then constructed a penalty model for delay of the bidding section construction period from the perspective of programs. Using the penalty model, we conducted a practical analysis of penalty for delay of the construction period of the Baoying station program in the South-to-North Water Diversion Project. The model can help determine the amount of penalty for delay of the construction period in bidding sections scientifically and reasonably, 展开更多
关键词 program establishment program management bidding section construction period critical path method (CPM) penaly model South-to-North Water Diversion Project
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Construction Approaches of Enterprise Innovation Network from the Perspective of Social Network
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作者 Guanghe HAN Siqi LI Jiayu ZHOU 《Asian Agricultural Research》 2020年第7期6-7,共2页
As an important means for enterprises to promote technological progress,product development and service level,innovation has an absolute role in enhancing enterprises'innovation strength and market strength.In the... As an important means for enterprises to promote technological progress,product development and service level,innovation has an absolute role in enhancing enterprises'innovation strength and market strength.In the context of frequent and rapid product replacement and shortened technological innovation cycle in modern society,through the embedding of social networks,forming platforms for higher education institutions,governments,capital markets,research institutions and intermediary links to promote the integration of innovation and capital development and make the most of every resource has become an important way.From the perspective of social network,the methods and necessary approaches for the establishment of enterprise innovation network are studied in this article. 展开更多
关键词 Enterprise innovation Social network construction method PATH
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The Form Characteristics and Construction of the Public Space of the Oasis Traditional Settlements in Turpan
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作者 SAIERJIANG Halike AMANGULI Aishan 《Journal of Landscape Research》 2020年第3期1-4,8,共5页
Based on the analysis of the form characteristics and construction of the public space of oasis traditional settlements in Turpan,and from the analysis and summary of the types,elements,scales and functions of the pub... Based on the analysis of the form characteristics and construction of the public space of oasis traditional settlements in Turpan,and from the analysis and summary of the types,elements,scales and functions of the public space of the traditional settlements,this study put forward that the public space of the oasis villages can be divided into point space,line space and plane space,and the formation and evolution rules of the public space of oasis traditional settlements in Turpan were obtained.Explore the role of public space in the construction of traditional settlements’ overall space,so as to provide reference for the development and renewal of public space of the current similar oasis settlements. 展开更多
关键词 Turpan Oasis settlements Public space Form characteristics construction method
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Construction Method of Modern Architecture under the Background of the Times
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作者 WANG Xiaojian YAN Yuewen 《Journal of Landscape Research》 2021年第5期15-17,24,共4页
Taking the development of the times as the background,the historical evolution of modern architecture is combed from the perspective of the initial stage of industrialization to post-industrialization and then to the ... Taking the development of the times as the background,the historical evolution of modern architecture is combed from the perspective of the initial stage of industrialization to post-industrialization and then to the information age.It can be seen that there is a close connection between development and modern architecture in the context of the times.With the advancement of science and technology,the construction of buildings has undergone varying degrees of changes due to aesthetics,materials,structure,humanities,and technology.Behind these changes are the results of the progress and development of social productivity.While changing people’s social cognition,it also changes the development process of architecture. 展开更多
关键词 Time background Modern architecture construction method
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Strong Stability Preserving IMEX Methods for Partitioned Systems of Differential Equations
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作者 Giuseppe Izzo Zdzislaw Jackiewicz 《Communications on Applied Mathematics and Computation》 2021年第4期719-758,共40页
We investigate strong stability preserving(SSP)implicit-explicit(IMEX)methods for partitioned systems of differential equations with stiff and nonstiff subsystems.Conditions for order p and stage order q=p are derived... We investigate strong stability preserving(SSP)implicit-explicit(IMEX)methods for partitioned systems of differential equations with stiff and nonstiff subsystems.Conditions for order p and stage order q=p are derived,and characterization of SSP IMEX methods is provided following the recent work by Spijker.Stability properties of these methods with respect to the decoupled linear system with a complex parameter,and a coupled linear system with real parameters are also investigated.Examples of methods up to the order p=4 and stage order q—p are provided.Numerical examples on six partitioned test systems confirm that the derived methods achieve the expected order of convergence for large range of stepsizes of integration,and they are also suitable for preserving the accuracy in the stiff limit or preserving the positivity of the numerical solution for large stepsizes. 展开更多
关键词 Partitioned systems of differential equations SSP property IMEX general linear methods construction of highly stable methods
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Rock mechanical problems and optimization for the long and deep diversion tunnels at Jinping Ⅱ hydropower station 被引量:4
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作者 Shiyong Wu Ge Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第4期314-328,共15页
According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimize... According to site-specific environments such as high water pressures, high in-situ stresses and strong rockbursts, the design scheme of the long and deep diversion tunnels at Jinping II hydropower station was optimized to ensure construction safety. New drainage tunnels were considered. Furthermore, lining structures and grouting pressures were modified during the excavation of tunnels. The construction scheme was updated dynamically based on the complex geological conditions. For instances, the diversion tunnels were first excavated by drilling and blasting method at the first stage of construction, and then by the combination method of tunnel boring machine (TBM) and drilling and blasting, and finally by drilling and blasting method. Through optimized scheme and updated construction scheme, the excavation of diversion tunnel #1 was successfully completed in June, 2011. This paper summarizes the key issues in rock mechanics associated with the construction of the long and deep diversion tunnels at Jinping II hydropower station. The experiences of design and construction obtained from this project could provide reference to similar projects. 展开更多
关键词 Jinping II hydropower station diversion tunnels optimized design construction method GROUTING
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CONSTRUCTION OF HIGH ORDER SYMPLECTIC PRK METHODS 被引量:8
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作者 Sun Geng(Institute of Mathematics, Academia Sinica, Beijing, China) 《Journal of Computational Mathematics》 SCIE CSCD 1995年第1期40-50,共11页
In this paper three classes of high order symplectic partitioned Runge-Kutta (PRK) methods, which are based on the W-transformation of Hairer and Wanner, and a particular class of diagonally implicit symplectic PRK me... In this paper three classes of high order symplectic partitioned Runge-Kutta (PRK) methods, which are based on the W-transformation of Hairer and Wanner, and a particular class of diagonally implicit symplectic PRK methods of arbitrarily high order, which are based on the composite algorithm, are constructed. In particular, the symplectically composite PRK methods of arbitrarily high order become explicit when applied to separable Hamiltonian systems. 展开更多
关键词 PRK construction OF HIGH ORDER SYMPLECTIC PRK methods MATH
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A constructive method for approximating trigonometric functions and their integrals
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作者 CHEN Xiao-diao WANG Long-quan WANG Yi-gang 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2020年第3期293-307,共15页
This paper presents an interpolation-based method(IBM)for approximating some trigonometric functions or their integrals as well.It provides two-sided bounds for each function,which also achieves much better approximat... This paper presents an interpolation-based method(IBM)for approximating some trigonometric functions or their integrals as well.It provides two-sided bounds for each function,which also achieves much better approximation effects than those of prevailing methods.In principle,the IBM can be applied for bounding more bounded smooth functions and their integrals as well,and its applications include approximating the integral of sin(x)/x function and improving the famous square root inequalities. 展开更多
关键词 Padéapproximant trigonometric function constructive method interpolation-based method two-sided bounds
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Constructing the three-qudit unextendible product bases with strong nonlocality
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作者 车碧琛 窦钊 +3 位作者 陈秀波 杨榆 李剑 杨义先 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第6期170-182,共13页
Unextendible product bases(UPBs)are interesting members of a family of orthogonal product bases.Here,we investigate the construction of 3-qudit UPBs with strong nonlocality.First,a UPB set in C^(3)■C^(3)■C^(3)of siz... Unextendible product bases(UPBs)are interesting members of a family of orthogonal product bases.Here,we investigate the construction of 3-qudit UPBs with strong nonlocality.First,a UPB set in C^(3)■C^(3)■C^(3)of size 19 is presented based on the shift UPBs.By mapping the system to a Rubik’s cube,we provide a general method of constructing UPBs in C^(d)■C^(d)■C^(d)of size(d-1)^(3)+2d+5,whose corresponding Rubik’s cube is composed of four parts.Second,for the more general case where the dimensions of parties are different,we extend the classical tile structure to the 3-qudit system and propose the tri-tile structure.By means of this structure,a C^(4)■C^(4)■C^(5)system of size 38 is obtained based on a C^(3)■C^(3)■C^(4)system of size 19.Then,we generalize this approach to the C^(d1)■C^(d2)■C^(d3)system which also consists of four parts.Our research provides a positive answer to the open question raised in by Halder et al.[Phys.Rev.Lett.122040403(2019)],indicating that there do exist UPBs that can exhibit strong quantum nonlocality without entanglement. 展开更多
关键词 strong nonlocality unextendible product bases tri-tile structure construction method
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Seismic hazard analysis for central-western Argentina 被引量:1
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作者 Salvador Daniel Gregori Rodolfo Christiansen 《Geodesy and Geodynamics》 2018年第1期25-33,共9页
In this study, we present a PSHA(Probabilistic Seismic Hazard Analysis) for the city of San Juan, which is located in the central-western region of Argentina(30°S-35.5°S; 66.5°W-71°W). In addit... In this study, we present a PSHA(Probabilistic Seismic Hazard Analysis) for the city of San Juan, which is located in the central-western region of Argentina(30°S-35.5°S; 66.5°W-71°W). In addition to crustal earthquakes provided by catalogues, recent paleoseismological and neotectonic investigations have permitted to consider events which occurred during the last 400 years.Four seismogenic sources that could cause damages to the studied site corresponding to Precordillera,Western Sierras Pampeanas, Basement of the Cuyana Basin and Cordillera Principal were identified.Based on the evaluation of the contribution of these sources,maximum moment magnitudes above 7.5(Mw) are expected.High values of SA(spectral acceleration)(0.2 and 1 s periods) and PGA(peak ground acceleration) were found in the city of San Juan, which suggests that it is located in a zone of high seismic hazard.Finally, the obtained SA spectra were compared with the seismic-resistant construction standards of Argentina INPRES-CIRSOC 103 [1]. Results suggest that for the city of San Juan and for a return period of475 years, it covers the seismic requirements of the structures. 展开更多
关键词 Probabilistic seismic hazard analysis Seismic-resistant construction standards Seismic sources Visual cumulative method
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Research on adaptive anti-rollover control of kiloton bridge transporting and laying vehicles
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作者 郭锐 Shi Yu +2 位作者 Wang Chao Tian Yaya Zhao Jingyi 《High Technology Letters》 EI CAS 2017年第2期203-211,共9页
The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concre... The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concrete beam size,irregular shape and complex transport conditions,which is called kiloton bridge transporting and laying vehicle.The anti-rollover performance of SPMT suspension system is studied,and vehicle side slip angle and load transfer rate(LTR) are regarded as the evaluation indexes.An active suspension adaptive anti-rollover control model of SPMT,in which roll stability affected by the structural parameters and control parameters,is built based on fuzzy PID,and the effectiveness of the control method is verified through real vehicle test. 展开更多
关键词 kiloton bridge transporting and laying vehicle SPMT construction method active suspension adaptive anti-rollover control
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Application of Gaussian beam pre-stack depth migration in rugged seabed
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作者 HAN Fuxing YI Xin +3 位作者 SUN Zhangqing HU Jia XU Baoyin XU Hai 《Global Geology》 2021年第2期119-128,共10页
Strong fluctuation of seabed,abrupt variation in depth and dip of seabed bring seismic imaging problems,such as irregular reflection waves,obvious multiple waves,serious lateral wave development,poor imaging on base s... Strong fluctuation of seabed,abrupt variation in depth and dip of seabed bring seismic imaging problems,such as irregular reflection waves,obvious multiple waves,serious lateral wave development,poor imaging on base surface and depression structure,low signal-to-noise ratio of middle and deep layers.In this paper,Gaussian beam migration imaging method is used to analyze the imaging effect of rugged seabed in deep water area,and the ray tracing method of wavefront construction method is used to analyze the kinematic characteristics of seismic waves.By improving the design of seismic data acquisition and observation system,imaging quality of fine structures is improved. 展开更多
关键词 Gaussian beam migration wavefront construction method Gaussian beam pre-stack depth rugged seabed
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Model Test for Dynamic Construction Mechanical Effect of Large-Span Loess Tunnel 被引量:4
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作者 何本国 朱永全 +1 位作者 叶朝良 张志强 《Journal of Shanghai Jiaotong university(Science)》 EI 2011年第1期112-117,共6页
It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failur... It has been a focus of debate for a large time on construction methods for large-span loess tunnel.Reasonable construction method has much effect on stability of tunnel and construction schedule.Deformation and failure of surrounding rock are quite complex.Associating with the large-span loess tunnel of Zhengzhou- Xi'an high-speed passenger rail line in China,large scale model test with geometric proportion 1:20 is applied to study on dynamic mechanical behavior of various construction methods.They include full-face excavation with support and no support,and benching method with support.It is found that pre-deformation and stress accumulation take place ahead of working face.The effects of three construction methods are further studied,particularly in terms of tunnel displacement and stress changes.It is revealed that benching method transfers load to an unexcavated area,limits horizontal deformation,reduces stress concentration effectively,lengthens the distance between location of peak for stress concentration and working face,and consequently increases stability.The model test results not only supply theoretical foundation for determination of reasonable construction method,but also can act as reference for similar tunnel and underground engineering construction. 展开更多
关键词 physical model construction method loess tunnel construction mechanics STABILITY
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A Certain Regular Property of the Method I Construction and Packing Measure 被引量:1
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作者 Sheng You WEN 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2007年第10期1769-1776,共8页
Let τ be a premeasure on a complete separable metric space and let τ* be the Method I measure constructed from τ. We give conditions on T such that τ* has a regularity as follows: Every τ*-measurable set has ... Let τ be a premeasure on a complete separable metric space and let τ* be the Method I measure constructed from τ. We give conditions on T such that τ* has a regularity as follows: Every τ*-measurable set has measure equivalent to the supremum of premeasures of its compact subsets. Then we prove that the packing measure has this regularity if and only if the corresponding packing premeasure is locally finite. 展开更多
关键词 method I construction REGULARITY packing premeasure packing measure
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A new construction method of LDPC codes for optical transmission systems
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作者 Jianguo YUAN Yuexing JIA Wenjuan BI Liang XU 《Frontiers of Optoelectronics》 2012年第3期311-316,共6页
Based on the construction method of system- atically constructed Gallager (SCG)(4, k) code, a new improved construction method of low density parity check (LDPC) code is proposed. Compared with the construction ... Based on the construction method of system- atically constructed Gallager (SCG)(4, k) code, a new improved construction method of low density parity check (LDPC) code is proposed. Compared with the construction method of SCG(4, k) codes improved before, the proposed construction method has some advantages, such as saving storage space and reducing computation complexity in the hardware implementation. And then LDPC(5929, 5624) code with 5.42% redundancy is constructed by the proposed method. The simulation results and analysis show that the constructed LDPC(5929, 5624) code has better error-correction performance, lower redundancy and lower decoding complexity than those of a classic Reed- Solomon (RS)(255, 239) code. Therefore, LDPC(5929, 5624) code, constructed by the proposed construction method on LDPC codes, can better suitable for optical transmission systems. 展开更多
关键词 low density parity check (LDPC) codes netcoding gain (NCG) construction method optical transmis-sion systems
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