期刊文献+
共找到15篇文章
< 1 >
每页显示 20 50 100
Dynamic Coordinated Management Model of Programme in Large-Scale Construction Company 被引量:2
1
作者 Feng Guo Yi-qi Chen Yi-qing Cai 《Frontiers of Engineering Management》 2015年第3期287-292,共6页
Large-scale construction companies develop rapidly when facing more and more opportunities and challenges of programme contracting. However, project management technology, not meeting the requirements of firm growth, ... Large-scale construction companies develop rapidly when facing more and more opportunities and challenges of programme contracting. However, project management technology, not meeting the requirements of firm growth, still stands proud, while relevant programme management methods have not been well studied. Therefore, this paper commences innovative application of coordinated management theory to programme management according to the need of changing the existing management mode in large-scale construction companies,then puts forward the dynamic coordinated management model composed of the dynamic coordination of function module, interface module, support module and evaluation module. Besides, coordination degree was introduced to make auxiliary analysis, so that companies can utilize internal and external resources more effectively to realize the goals of programme management as well as enterprise strategy. 展开更多
关键词 large-scale construction company PROGRAMME dynamic coordinated management MODEL
原文传递
Contact dynamics of elasto-plastic thin beams simulated via absolute nodal coordinate formulation 被引量:4
2
作者 Qing-Tao Wang Qiang Tian Hai-Yan Hu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第3期525-534,共10页
Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation(ANCF). The int... Under the frame of multibody dynamics, the contact dynamics of elasto-plastic spatial thin beams is numerically studied by using the spatial thin beam elements of absolute nodal coordinate formulation(ANCF). The internal force of the elasto-plastic spatial thin beam element is derived under the assumption that the plastic strain of the beam element depends only on its longitudinal deformation.A new body-fixed local coordinate system is introduced into the spatial thin beam element of ANCF for efficient contact detection in the contact dynamics simulation. The linear isotropic hardening constitutive law is used to describe the elasto-plastic deformation of beam material, and the classical return mapping algorithm is adopted to evaluate the plastic strains. A multi-zone contact approach of thin beams previously proposed by the authors is also introduced to detect the multiple contact zones of beams accurately, and the penalty method is used to compute the normal contact force of thin beams in contact. Four numerical examples are given to demonstrate the applicability and effectiveness of the proposed elasto-plastic spatial thin beam element of ANCF for flexible multibody system dynamics. 展开更多
关键词 Elasto-plastic deformation Linear isotropic hardening constitutive law Absolute nodal coordinate formulation(ANCF) Thin beam multi-zone contact dynamics
下载PDF
Coordinated dynamic mission planning scheme for intelligent multi-agent systems
3
作者 彭军 文孟飞 +2 位作者 谢国祺 张晓勇 Kuo-chi LIN 《Journal of Central South University》 SCIE EI CAS 2012年第11期3170-3179,共10页
Mission planning was thoroughly studied in the areas of multiple intelligent agent systems,such as multiple unmanned air vehicles,and multiple processor systems.However,it still faces challenges due to the system comp... Mission planning was thoroughly studied in the areas of multiple intelligent agent systems,such as multiple unmanned air vehicles,and multiple processor systems.However,it still faces challenges due to the system complexity,the execution order constraints,and the dynamic environment uncertainty.To address it,a coordinated dynamic mission planning scheme is proposed utilizing the method of the weighted AND/OR tree and the AOE-Network.In the scheme,the mission is decomposed into a time-constraint weighted AND/OR tree,which is converted into an AOE-Network for mission planning.Then,a dynamic planning algorithm is designed which uses task subcontracting and dynamic re-decomposition to coordinate conflicts.The scheme can reduce the task complexity and its execution time by implementing real-time dynamic re-planning.The simulation proves the effectiveness of this approach. 展开更多
关键词 weighted AND/OR tree multiple intelligent agent coordinated dynamic mission planning AOE-NETWORK
下载PDF
OPTIMAL DYNAMIC LOAD DISTRIBUTION OF MULTIPLE COOPERATING ROBOT MANIPULATORS 被引量:1
4
作者 Zhao Yongsheng Huang Zhen Gao Feng(Yanshan University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1994年第2期108-111,共17页
For the situation of multiple cooperating manipulators handling a single object,an equilibrium equation is presented in which the manipulator dynamics and control forces/torques are taken into account,and a expression... For the situation of multiple cooperating manipulators handling a single object,an equilibrium equation is presented in which the manipulator dynamics and control forces/torques are taken into account,and a expression is derived to allow the optimal dynamic load distribution of the combined system can be made. 展开更多
关键词 Multiple cooperating robot manipulators Optimal distribution dynamic coordinate
全文增补中
Dynamic modeling and simulation for the flexible spacecraft with dynamic stiffening 被引量:2
5
作者 李崔春 孟秀云 刘藻珍 《Journal of Beijing Institute of Technology》 EI CAS 2015年第3期305-312,共8页
A rigid flexible coupling physical model which can represent a flexible spacecraft is investigated in this paper. By applying the mechanics theory in a non-inertial coordinate system,the rigid flexible coupling dynami... A rigid flexible coupling physical model which can represent a flexible spacecraft is investigated in this paper. By applying the mechanics theory in a non-inertial coordinate system,the rigid flexible coupling dynamic model with dynamic stiffening is established via the subsystemmodeling framework. It is clearly elucidated for the first time that,dynamic stiffening is produced by the coupling effect of the centrifugal inertial load distributed on the beamand the transverse vibration deformation of the beam. The modeling approach in this paper successfully avoids problems which are caused by other popular modeling methods nowadays: the derivation process is too complex by using only one dynamic principle; a clearly theoretical explanation for dynamic stiffening can't be provided. First,the continuous dynamic models of the flexible beamand the central rigid body are established via structural dynamics and angular momentumtheory respectively. Then,based on the conclusions of orthogonalization about the normal constrained modes,the finite dimensional dynamic model suitable for controller design is obtained. The numerical simulation validations showthat: dynamic stiffening is successfully incorporated into the dynamic characteristics of the first-order model established in this paper,which can indicate the dynamic responses of the rigid flexible coupling system with large overall motion accurately,and has a clear modeling mechanism,concise expressions and a good convergence. 展开更多
关键词 non-inertial coordinate system large overall motion rigid flexible coupling dynamic stiffening normal constrained mode
下载PDF
Combined Control Allocation and Sliding Mode Control in the Dynamic Control of a Vehicle with Eight In-Wheel Motors
6
作者 Rui Zhang Chengning Zhang 《Journal of Beijing Institute of Technology》 EI CAS 2017年第1期58-66,共9页
An eight wheel independently driving steering(8 WIDBS)electric vehicle is studied in this paper.The vehicle is equipped with eight in-wheel motors and a steer-by-wire system.A hierarchically coordinated vehicle dyna... An eight wheel independently driving steering(8 WIDBS)electric vehicle is studied in this paper.The vehicle is equipped with eight in-wheel motors and a steer-by-wire system.A hierarchically coordinated vehicle dynamic control(HCVDC)system,including a high-level vehicle motion controller,a control allocation,an inverse tire model and a lower-level slip/slip angle controller,is proposed for the over-actuated vehicle system.The high-level sliding mode vehicle motion controller is designed to produce desired total forces and yaw moment,distributed to longitudinal and lateral forces of each tire by an advanced control allocation method.And the slip controller is designed to use a sliding mode control method to follow the desired slip ratios by manipulating the corresponding in-wheel motor torques.Evaluation of the overall system is accomplished by sine maneuver simulation.Simulation results confirm that the proposed control system can coordinate among the redundant and constrained actuators to achieve the vehicle dynamic control task and improve the vehicle stability. 展开更多
关键词 hierarchically coordinated vehicle dynamic control control allocation sliding modecontrol
下载PDF
A first-order dynamical model of hierarchical triple stars and its application
7
作者 Xing-Bo Xu Fang Xia Yan-Ning Fu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2015年第11期1857-1866,共10页
For most hierarchical triple stars, the classical double two-body model of zeroth-order cannot describe the motions of the components under the current observational accuracy. In this paper, Marchal's first-order ana... For most hierarchical triple stars, the classical double two-body model of zeroth-order cannot describe the motions of the components under the current observational accuracy. In this paper, Marchal's first-order analytical solution is implemented and a more efficient simplified version is applied to real triple stars. The results show that, for most triple stars, the proposed first-order model is preferable to the zerothorder model both in fitting observational data and in predicting component positions. 展开更多
关键词 hierarchical triple fitting simplified stars dynamical Delaunay positions observational coordinate
下载PDF
Highly Stretchable and Tunable Thermo-fluorochromic Polymer Elastomer through Eu^(3+)Dynamic Coordination Cross-linking
8
作者 Qiu-Li Tan Kai Gou +4 位作者 Jing-Zhi Tang Ming-Hui Wei Chong Wang Yi-Jing Nie Geng-Sheng Weng 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第10期1449-1458,I0008,共11页
Thermochromic polymers with tunable thermochromism,high stretchability and mechanical strength are of interests for optical information storage and encryption.In this work,we demonstrate a new design of thermo-fluoroc... Thermochromic polymers with tunable thermochromism,high stretchability and mechanical strength are of interests for optical information storage and encryption.In this work,we demonstrate a new design of thermo-fluorochromic carboxylated nitrile butadiene rubber(XNBR)elastomer cross-linked by Eu^(3+)-COOH dynamic coordination with deprotonated imidazole(DPIm)as the ancillary ligand.The presence of DPIm not only improves the mechanical strength and stretchability,but also dramatically intensifies the fluorescence emission and lifetime of the Eu-containing elastomer.The elastomer behaves reversible thermo-fluorochromism with easily tunable transition temperature and emission intensity by the simple change of the deprotonation degree of imidazole.The facile tunable thermo-fluorochromism,exceptional mechanical strength,and high stretchability(up to about 5000%)enable the Eu-containing XNBR elastomer with potential applications in soft electronics where optical information storage and encryption are required. 展开更多
关键词 dynamic coordination THERMOCHROMISM Highly stretchable ELASTOMER Europium
原文传递
Coupling and coordinated evolution characteristics of regional economy-energy-carbon emission multiple systems:A case study of main China's Basin
9
作者 Lu Chen Xin Li +4 位作者 Jingyi Zhao Xinyu Kang Lu Liu Minxi Wang Wu Chen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第6期204-218,共15页
Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to ... Comprehensive analysis of the Economy-Energy-Carbon Emission(EECE)system is beneficial for promoting sustainable social development.This study analyzes the system development of major watersheds in China from 2010 to 2019.The research fully considers the system’s internal and external inputs and outputs and proposes an evaluation index system for regional EECE coupling and coordinated development.Then,using the difference in system weight allocation to improve the coupling and coordination model,the study explores the dynamic system’s coupling and coordination.The results show that(1)The development of the system structure is relatively stable,but the overall development status is not ideal;(2)The downstream of China’s main river basins has obvious economic advantages,while the energy system fluctuates greatly.The efficiency of the carbon emission system will decrease in areas with rapid economic development.The coupling and coordination level of the EECE system is better in the Yangtze River Basin than in the Yellow River Basin;(3)From the perspective of dynamic coordinated development,the main river basins have been divided into two states since 2012,but it is relatively stable overall.Regional dynamic coordination is often at a disadvantage in regions with rapid economic and energy development;(4)The coupling coordination degree of the two river basins has significant positive spatial autocorrelation.Most provinces’significant spatial clustering characteristics of the coupling coordination degree are High-High type.Low-Low type provinces are mainly concentrated downstream.The research process has certain reference significance for the collaborative governance of complex regional systems. 展开更多
关键词 System structure Efficiency measure Coupling mechanism dynamic coordination
原文传递
Visible light responsive spiropyran derivatives based on dynamic coordination bonds 被引量:1
10
作者 Xiong Xiao Wei Zheng +1 位作者 Yue Zhao Cheng-Hui Li 《Chinese Chemical Letters》 SCIE CAS CSCD 2023年第2期506-510,共5页
Spiropyrans(SPs) are a well-known class of photochromic compounds and have found widespread application due to their unique properties. However, for many conventional SPs, high energy ultraviolet(UV)light is commonly ... Spiropyrans(SPs) are a well-known class of photochromic compounds and have found widespread application due to their unique properties. However, for many conventional SPs, high energy ultraviolet(UV)light is commonly essential to drive photoisomerization, leading to poor fatigue resistance. Moreover, the practical application of spiropyrans is hindered by their fast fading speed due to the instability of closed forms(SP) or open forms(MC). Herein, we disclose a novel strategy to address these challenges through introducing both electron-donating substituents to stabilize the SP and dynamic coordination bonds to stabilize the MC. The resulting new spiropyrans complexes exhibit negative photochromic properties, with fast visible light response, good stability of both SP and MC, and significantly improved fatigue resistance. 展开更多
关键词 Negativephotochromic SPIROPYRAN Visiblelightresponsive dynamic coordination bonds Design guidelines
原文传递
Multi-scale interactions in interpersonal coordination
11
作者 Tehran J.Davis Thomas R.Brooks James A.Dixon 《Journal of Sport and Health Science》 SCIE 2016年第1期25-34,共10页
Background:Interpersonal coordination is an essential aspect of daily life,and crucial to performance in cooperative and competitive team sports.While empirical research has investigated interpersonal coordination usi... Background:Interpersonal coordination is an essential aspect of daily life,and crucial to performance in cooperative and competitive team sports.While empirical research has investigated interpersonal coordination using a wide variety of analytical tools and frameworks,to date very few studies have employed multifractal techniques to study the nature of interpersonal coordination across multiple spatiotemporal scales.In the present study we address this gap.Methods:We investigated the dynamics of a simple dyadic interpersonal coordination task where each participant manually controlled a virtual object in relation to that of his or her partner.We tested whether the resulting hand-movement time series exhibits multi-scale properties and whether those properties are associated with successful performance.Results:Using the formalism of multifractals,we show that the performance on the coordination task is strongly multi-scale,and that the multi-scale properties appear to arise from interaction-dominant dynamics.Further,we find that the measure of across-scale interactions,multifractal spectrum width,predicts successful performance at the level of the dyad.Conclusion:The results are discussed with respect to the implications of multifractals and interaction-dominance for understanding control in an interpersonal context. 展开更多
关键词 Component-dominant dynamics Interaction-dominant dynamics Interpersonal coordination Multifractal Time series analysis
下载PDF
Research on uplink coordinated transmission schemes in LTE-advanced systems 被引量:1
12
作者 WANG Ya-feng WEI Guo-xing +1 位作者 YANG Da-cheng WEI Xiang 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2011年第2期72-77,共6页
The investigation of inter-cell interference mitigation techniques is a key area in wireless communications.Coordinated multiple points(CoMP) transmission/reception is a candidate technique for interference cancella... The investigation of inter-cell interference mitigation techniques is a key area in wireless communications.Coordinated multiple points(CoMP) transmission/reception is a candidate technique for interference cancellation in 3GPP LTE-Advanced system.However,the coordination scheme in CoMP remains a key research problem to be solved,which will have a strong influence on the performance of CoMP.In this paper,a novel coordinated transmission scheme is proposed for the uplink LTE-Advanced system.In our scheme,several base transceiver stations(BTS) and users are selected as coordination partners which form a CoMP cluster.Joint processing is used at the receiver to mitigate interference.From the perspective of coordinated partner selection,our scheme can be divided into static and dynamic coordination which are both considered to fully exploit the throughput gain of CoMP.The proposed schemes are evaluated by system level simulation and compared with the conventional LTE system based upon single cell processing.Our simulation results demonstrate that the proposed schemes attain superior performance as opposed to the conventional system in terms of cell average and cell edge throughput. 展开更多
关键词 COMP joint processing inter-cell interference static coordination dynamic coordination
原文传递
A New Stable Version of the SPH Method in Lagrangian Coordinates 被引量:1
13
作者 A.Ferrari M.Dumbser +1 位作者 E.F.Toro A.Armanini 《Communications in Computational Physics》 SCIE 2008年第7期378-404,共27页
The purpose of this paper is to solve some of the trouble spots of the classical SPH method by proposing an alternative approach.First,we focus on the problem of the stability for two different SPH schemes,one is base... The purpose of this paper is to solve some of the trouble spots of the classical SPH method by proposing an alternative approach.First,we focus on the problem of the stability for two different SPH schemes,one is based on the approach of Vila[25]and another is proposed in this article which mimics the classical 1D LaxWendroff scheme.In both approaches the classical SPH artificial viscosity term is removed preserving nevertheless the linear stability of the methods,demonstrated via the von Neumann stability analysis.Moreover,the issue of the consistency for the equations of gas dynamics is analyzed.An alternative approach is proposed that consists of using Godunov-type SPH schemes in Lagrangian coordinates.This not only provides an improvement in accuracy of the numerical solutions,but also assures that the consistency condition on the gradient of the kernel function is satisfied using an equidistant distribution of particles in Lagrangian mass coordinates.Three different Riemann solvers are implemented for the first-order Godunov type SPH schemes in Lagrangian coordinates,namely the Godunov flux based on the exact Riemann solver,the Rusanov flux and a new modified Roe flux,following the work of Munz[17].Some well-known numerical 1D shock tube test cases[22]are solved,comparing the numerical solutions of the Godunov-type SPH schemes in Lagrangian coordinates with the first-order Godunov finite volume method in Eulerian coordinates and the standard SPH scheme with Monaghan’s viscosity term. 展开更多
关键词 SPH meshfree particle methods Riemann solvers gas dynamics in Lagrangian coordinates Godunov type schemes.
原文传递
OVERVIEW OF COMPLEX SYSTEMS IN SPORT 被引量:3
14
作者 BALAGUE Natàlia TORRENTS Carlota +2 位作者 HRISTOVSKI Robert DAVIDS Keith ARAUJO Duarte 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2013年第1期4-13,共10页
The complex systems approach offers an opportunity to replace the extant pre-dominant mechanistic view on sport-related phenomena.The emphasis on the environment-system relationship,the applications of complexity prin... The complex systems approach offers an opportunity to replace the extant pre-dominant mechanistic view on sport-related phenomena.The emphasis on the environment-system relationship,the applications of complexity principles,and the use of nonlinear dynamics mathematical tools propose a deep change in sport science.Coordination dynamics,ecological dynamics,and network approaches have been successfully applied to the study of different sport-related behaviors,from movement patterns that emerge at different scales constrained by specific sport contexts to game dynamics.Sport benefit from the use of such approaches in the understanding of technical,tactical,or physical conditioning aspects which change their meaning and dilute their frontiers.The creation of new learning and training strategies for teams and individual athletes is a main practical consequence.Some challenges for the future are investigating the influence of key control parameters in the nonlinear behavior of athlete-environment systems and the possible relatedness of the dynamics and constraints acting at different spatio-temporal scales in team sports.Modelling sport-related phenomena can make useful contributions to a better understanding of complex systems and vice-versa. 展开更多
关键词 Constraints-led approach coordination dynamics performer-environment system self- organization team dynamics.
原文传递
A fast on-demand preparation of injectable self-healing nanocomposite hydrogels for efficient osteoinduction
15
作者 Panpan Pan Xiao Chen +5 位作者 Huaran Xing Yonghui Deng Jingdi Chen Fahad AAlharthi Abdulaziz AAlghamdi Jiacan Su 《Chinese Chemical Letters》 SCIE CAS CSCD 2021年第7期2159-2163,共5页
Injectable hydrogels have been considered as promising materials for bone regeneration,but their osteoinduction and mechanical performance are yet to be improved.In this study,a novel biocompatible injectable and self... Injectable hydrogels have been considered as promising materials for bone regeneration,but their osteoinduction and mechanical performance are yet to be improved.In this study,a novel biocompatible injectable and self-healing nano hybrid hydrogel was on-demand prepared via a fast(within 30 s)and easy gelation approach by reversible Schiff base formed between-CH=O of oxidized sodium alginate(OSA)and-NH2 of glycol chitosan(GCS)mixed with calcium phosphate nanoparticles(CaP NPs).Its raw materials can be ready in large quantities by a simple synthesis process.The mechanical strength,degradation and swelling behavior of the hydrogel can be readily controlled by simply controlling the molar ratio of-CH=O and-NH2.This hydrogel exhibits pH responsiveness,good degradability and biocompatibility.The hydrogel used as the matrix for mesenchymal stem cells can significantly induce the proliferation,differentiation and osteoinduction in vitro.These results showed this novel hydrogel is an ideal candidate for applications in bone tissue regeneration and drug delivery. 展开更多
关键词 dynamic coordination Nanocomposite hydrogels Fast and easy on-demand preparation Injectable and self-healing abilities Stem cell osteoinduction
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部