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The role delegation authorization model of a computer-supported cooperative design system

XU Hongxue, LIU Yongxian, SHENG Zhongqi, GUO Xiuying

《机械工程前沿（英文）》 2007年 第2卷 第2期   页码 201-204 doi: 10.1007/s11465-007-0034-6

摘要： According to the specific characteristics of a computer-supported cooperative design (CSCD) system, the characteristics of role delegation authorization (RDA) are analyzed and deduced, and a set of fitful status is arrived at. Because of the diversified characteristics of RDA features in different systems, the RDA model has multi-varying status. On the basis of the basic model of role-based access control (RBAC), some basic characteristics of RDA are summed up. Then, according to the specific characteristics of CSCD system, the characteristics of RDA are recombined to develop a RDA model that is suitable for the CSCD system. It is different from the conventional role authorization models of RBAC, that is, it adopts the decentralized authorization management instead of the centralized one in CSCD system, which makes the management more flexible. This model is verified through a specific case of CSCD system.

关键词： fitful     RBAC     different     multi-varying     CSCD    

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Time-varying formation tracking for uncertain second-order nonlinearmulti-agent systems

Mao-peng RAN, Li-hua XIE, Jun-cheng LI

《信息与电子工程前沿（英文）》 2019年 第20卷 第1期   页码 76-87 doi: 10.1631/FITEE.1800557

摘要：

Our study is concerned with the time-varying formation tracking problem for second-order multi-agent systems that are subject to unknown nonlinear dynamics and external disturbance, and the states of the followers form a predefined time-varying formation while tracking the state of the leader. The total uncertainty lumps the unknown nonlinear dynamics and the external disturbance, and is regarded as an extended state of the agent. To estimate the total uncertainty, we design an extended state observer (ESO). Then we propose a novel ESO based time-varying formation tracking protocol. It is proved that, under the proposed protocol, the ESO estimation error and the time-varying formation tracking error can be made arbitrarily small. An application to the target enclosing problem for multiple unmanned aerial vehicles (UAVs) verifies the effectiveness and superiority of the proposed approach.

关键词： Multi-agent system     Time-varying formation     Formation tracking     Nonlinear dynamics     Extended state observer (ESO)    

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A multiscale-contour-based interpolation framework for generating a time-varying quasi-dense point cloud

Chu-hua HUANG,Dong-ming LU,Chang-yu DIAO

《信息与电子工程前沿（英文）》 2016年 第17卷 第5期   页码 422-434 doi: 10.1631/FITEE.1500316

摘要： To speed up the reconstruction of 3D dynamic scenes in an ordinary hardware platform, we propose an efficient framework to reconstruct 3D dynamic objects using a multiscale-contour-based interpolation from multi-view videos. Our framework takes full advantage of spatio-temporal-contour consistency. It exploits the property to interpolate single contours, two neighboring contours which belong to the same model, and two contours which belong to the same view at different times, corresponding to point-, contour-, and model-level interpolations, respectively. The framework formulates the interpolation of two models as point cloud transport rather than non-rigid surface deformation. Our framework speeds up the reconstruction of a dynamic scene while improving the accuracy of point-pairing which is used to perform the interpolation. We obtain a higher frame rate, spatio-temporal-coherence, and a quasi-dense point cloud sequence with color information. Experiments with real data were conducted to test the efficiency of the framework.

关键词： Multi-view video     Free-viewpoint video     Point-pair     Multiscale-contour-based interpolation     Spatio-temporal-contour     Consistency     Time-varying point cloud sequence    

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Position-varying surface roughness prediction method considering compensated acceleration in milling

《机械工程前沿（英文）》 2021年 第16卷 第4期   页码 855-867 doi: 10.1007/s11465-021-0649-z

摘要： Machined surface roughness will affect parts’ service performance. Thus, predicting it in the machining is important to avoid rejects. Surface roughness will be affected by system position dependent vibration even under constant parameter with certain toolpath processing in the finishing. Aiming at surface roughness prediction in the machining process, this paper proposes a position-varying surface roughness prediction method based on compensated acceleration by using regression analysis. To reduce the stochastic error of measuring the machined surface profile height, the surface area is repeatedly measured three times, and Pauta criterion is adopted to eliminate abnormal points. The actual vibration state at any processing position is obtained through the single-point monitoring acceleration compensation model. Seven acceleration features are extracted, and valley, which has the highest R-square proving the effectiveness of the filtering features, is selected as the input of the prediction model by mutual information coefficients. Finally, by comparing the measured and predicted surface roughness curves, they have the same trends, with the average error of 16.28% and the minimum error of 0.16%. Moreover, the prediction curve matches and agrees well with the actual surface state, which verifies the accuracy and reliability of the model.

关键词： surface roughness prediction     compensated acceleration     milling     thin-walled workpiece    

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Attuned design of demand response program and M-FACTS for relieving congestion in a restructured market environment

Y. HASHEMI,H. SHAYEGHI,B. HASHEMI

《能源前沿（英文）》 2015年 第9卷 第3期   页码 282-296 doi: 10.1007/s11708-015-0366-6

摘要： This paper addresses the attuned use of multi-converter flexible alternative current transmission systems (M-FACTS) devices and demand response (DR) to perform congestion management (CM) in the deregulated environment. The strong control capability of the M-FACTS offers a great potential in solving many of the problems facing electric utilities. Besides, DR is a novel procedure that can be an effective tool for reduction of congestion. A market clearing procedure is conducted based on maximizing social welfare (SW) and congestion as network constraint is paid by using concurrently the DR and M-FACTS. A multi-objective problem (MOP) based on the sum of the payments received by the generators for changing their output, the total payment received by DR participants to reduce their load and M-FACTS cost is systematized. For the solution of this problem a nonlinear time-varying evolution (NTVE) based multi-objective particle swarm optimization (MOPSO) style is formed. Fuzzy decision-making (FDM) and technique for order preference by similarity to ideal solution (TOPSIS) approaches are employed for finding the best compromise solution from the set of Pareto-solutions obtained through multi-objective particle swarm optimization-nonlinear time-varying evolution (MOPSO-NTVE). In a real power system, Azarbaijan regional power system of Iran, comparative analysis of the results obtained from the application of the DR & unified power flow controller (UPFC) and the DR & M-FACTS are presented.

关键词： multi-converter flexible alternative current transmission systems (M-FACTS)     demand response     fuzzy decision making     multi-objective particle swarm optimization-nonlinear time-varying evolution (MOPSO-NTVE)    

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Elastic analysis of heterogeneous thick-walled spherical pressure vessels with parabolic varying properties

Keyhan KARAMI, Majid ABEDI, Mohammad ZAMANI NEJAD, Mohammad Hassan LOTFIAN

《机械工程前沿（英文）》 2012年 第7卷 第4期   页码 433-438 doi: 10.1007/s11465-012-0336-1

摘要：

On the basis of plane elasticity theory (PET), the displacement and stress components in a thick-walled spherical pressure vessels made of heterogeneous materials subjected to internal and external pressure is developed. The mechanical properties except the Poisson’s ratio are assumed to obey the parabolic variations throughout the thickness. Effect of material inhomogeneity on the elastic deformations and stresses is investigated. The analytical solutions and the solutions carried out through the FEM have a good agreement. The values used in this study are arbitrary chosen to demonstrate the effect of inhomogeneity on displacements, and stresses distributions.

关键词： thick-walled spherical vessels     heterogeneous materials     FGM     FEM     parabolic varying properties    

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Effects of time-varying liquid bridge forces on rheological properties, and resulting extrudability and

《结构与土木工程前沿（英文）》   页码 1295-1309 doi: 10.1007/s11709-023-0999-1

摘要： Extrudability and constructability are two important, yet contradictory issues pertaining to the construction of three-dimensional (3D) printing concrete. Extrudability is easily achieved when 3D printing cement mortar has a high water content and low cohesion, but the printed structure is easily collapsible. However, a 3D printing cement mortar with a low water content and high cohesion has a relatively stable printed structure although the cement mortar might not be extrudable. This study proposes a particle-based method to simulate 3D printing mortar extrusion and construction as an overall planning tool for building design. First, a discrete element model with time-varying liquid bridge forces is developed to investigate the microscopic effects of these forces on global rheological properties. Next, a series of numerical simulations relevant to 3D printable mortar extrudability and constructability are carried out. The study demonstrates that the effects of time-varying liquid bridge forces on rheological properties and the resulting extrudability and constructability of 3D printing mortar are considerable. Furthermore, an optimized region that satisfies both the extrusion and construction requirements is provided for 3D printing industry as a reference.

关键词： particle-based simulation     liquid bridge force     rheological property     3D printing mortar     extrudability     constructability    

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Experimental research on seismic behavior of recycled concrete frame under varying cyclic loading

SUN Yuedong, XIAO Jianzhuang, ZHOU Deyuan

《结构与土木工程前沿（英文）》 2008年 第2卷 第4期   页码 302-308 doi: 10.1007/s11709-008-0050-6

摘要： A study is conducted on the seismic behavior of one natural concrete frame and two recycled concrete frames with 100% recycled coarse aggregate whose scales are 1:2 entirely, and a comparative study is conducted under low-reversed cyclic lateral loading and different vertical loading. This work aims to estimate the failure mechanism, hysteresis loops, displacement ductility, deterioration of strength and stiffness and energy dissipation of recycled concrete frames under low-reversed cyclic loading as well as the influence of different vertical loading. Analysis on the basis of the experiment proves that it is entirely feasible to apply recycled concrete to practical engineering for the sake of its good seismic behaviors. Theoretical base is provided for further study and practical application of recycled concrete structure.

关键词： different     aggregate     stiffness     practical application     % recycled    

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reference tracking control design for a class of nonlinear systems with time-varying delays

Mei-qin LIU,Hai-yang CHEN,Sen-lin ZHANG

《信息与电子工程前沿（英文）》 2015年 第16卷 第9期   页码 759-768 doi: 10.1631/FITEE.1500053

摘要： This paper investigates the trajectory tracking control for a class of nonlinear systems with timevarying delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality (LMI) technique. A unified model consisting of a linear delayed dynamic system and a bounded static nonlinear operator is introduced, which covers most of the nonlinear systems with bounded nonlinear terms, such as the one-link robotic manipulator, chaotic systems, complex networks, the continuous stirred tank reactor (CSTR), and the standard genetic regulatory network (SGRN). First, the definition of the tracking control is given. Second, the performance analysis of the closed-loop system including this unified model, reference model, and state feedback controller is presented. Then criteria on the tracking controller design are derived in terms of LMIs such that the output of the closed-loop system tracks the given reference signal in the sense. The reference model adopted here is modified to be more flexible. A scaling factor is introduced to deal with the disturbance such that the control precision is improved. Finally, a CSTR system is provided to demonstrate the effectiveness of the established control laws.

关键词： H∞     reference tracking     Nonlinear system     State feedback control     Time-varying delays     Unified model    

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Predicting the response of continuous RC deep beams under varying levels of differential settlement

M. Z. NASER, R. A. HAWILEH

《结构与土木工程前沿（英文）》 2019年 第13卷 第3期   页码 686-700 doi: 10.1007/s11709-018-0506-2

摘要： This paper investigates the effect of differential support settlement on shear strength and behavior of continuous reinforced concrete (RC) deep beams. A total of twenty three-dimensional nonlinear finite element models were developed taking into account various constitutive laws for concrete material in compression (crushing) and tension (cracking), steel plasticity (i.e., yielding and strain hardening), bond-slip at the concrete and steel reinforcement interface as well as unique behavior of spring-like support elements. These models are first validated by comparing numerical predictions in terms of load-deflection response, crack propagation, reaction distribution, and failure mode against that of measured experimental data reported in literature. Once the developed models were successfully validated, a parametric study was designed and performed. This parametric study examined number of critical parameters such as ratio and spacing of the longitudinal and vertical reinforcement, compressive and tensile strength of concrete, as well as degree (stiffness) and location of support stiffness to induce varying levels of differential settlement. This study also aims at presenting a numerical approach using finite element simulation, supplemented with coherent assumptions, such that engineers, practitioners, and researchers can carry out simple, but yet effective and realistic analysis of RC structural members undergoing differential settlements due to variety of load actions.

关键词： concrete     continuous beams     deep beams     finite element modeling     support settlement    

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一种工业过程时变参数估计新算法——修正目标函数法

张承慧

《中国工程科学》 2001年 第3卷 第11期   页码 54-59

摘要：

针对某些工业过程控制参数高度时变的特点和LS拟合算法存在病态估计的现象，提出了一类基于 修正目标函数的时变参数估计算法，并给出递推辅助变量算法。此类算法不仅具有较强的实时跟踪能力和较高 的估计精度，而且能克服病态估计，摆脱了伪随机信号在工程中带来的麻烦。新算法没有增加计算量，非常适 合于工程应用，仿真及实际应用结果都证明新算法是有效的。文中给出了有关新算法的定理及其证明。

关键词： 参数估计     计算方法     LS算法     时变系统     工业生产    

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时变网络的收敛性及其应用 Research Articles

王庆领

《信息与电子工程前沿（英文）》 2021年 第22卷 第1期   页码 1-140 doi: 10.1631/FITEE.2000160

摘要： 本文分析一类时变网络的收敛性。将收敛性质应用于具有未知控制方向的非线性多智能体系统协同控制问题，并提出一类新的基于Nussbaum型函数的控制策略。若时变网络是准平衡的，则所提控制策略可实现具有未知控制方向的非线性多智能体系统的收敛。所提算法的一个重要特点是，该算法可采用经典的Nussbaum型函数解决控制方向未知且不等同问题。最后，提出一个仿真案例验证所提算法的有效性。

关键词： 时变网络；未知控制方向；Nussbaum型函数；准平衡条件    

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Control of peak pressures of an HCCI engine under varying swirl and operating parameters

T. KARTHIKEYA SHARMA,G. AMBA PRASAD RAO,K. MADHU MURTHY

《能源前沿（英文）》 2016年 第10卷 第3期   页码 337-346 doi: 10.1007/s11708-016-0401-2

摘要： The major advantages of homogeneous charge compression ignition (HCCI) are high efficiency in combination with low NO -emissions. However, one of the major challenges with HCCI is the control of higher peak pressures which may damage the engine, limiting the HCCI engine life period. In this paper, an attempt is made to analyze computationally the effect of induction swirl in controlling the peak pressures of an HCCI engine under various operating parameters. A single cylinder 1.6 L reentrant piston bowl diesel engine is chosen. For computational analysis, the ECFM-3Z model of STAR –CD is considered because it is suitable for analyzing the combustion processes in SI and CI engines. As an HCCI engine is a hybrid version of SI and CI engines, the ECFM-3Z model with necessary modifications is used to analyze the peak pressures inside the combustion chamber. The ECFM-3Z model for HCCI mode of combustion is validated with the existing literature to make sure that the results obtained are accurate. Numerical experiments are performed to study the effect of varying properties like speed of the engine, piston bowl geometry, exhaust gas recirculation (EGR) and equivalence ratio under different swirl ratios in controlling the peak pressures inside the combustion chamber. The results show that the swirl ratio has a considerable impact on controlling the peak pressures of HCCI engine. A reduction in peak pressures are observed with a swirl ratio of 4 because of reduced in cylinder temperatures. The combined effect of four operating parameters, i.e., the speed of the engine, piston bowl geometry, EGR, and equivalence ratio with swirl ratios suggest that lower intake temperatures, reentrant piston bowl, higher engine speeds and higher swirl ratios are favorable in controlling the peak pressures.

关键词： HCCI engine     ECFM-3Z     Swirl ratio     peak pressures     engine speed     piston bowl geometry    

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基于非脆弱采样数据控制的非线性多智能体系统同步控制及其在电路系统中的应用 Research Article

Stephen AROCKIA SAMY1,Raja RAMACHANDRAN2,Pratap ANBALAGAN3,曹阳4

《信息与电子工程前沿（英文）》 2023年 第24卷 第4期   页码 553-566 doi: 10.1631/FITEE.2200181

摘要： 设计了一个非脆弱采样数据控制方案，用于互连耦合电路系统（多智能体系统）的渐近同步标准。该方案对所考虑的多智能体系统在时变延迟情况下作同步分析。通过构建合适的李亚普诺夫函数，得出线性矩阵不等式成立的充分条件，确保多智能体领导者和跟随者系统之间的同步。最后，给出两个数值案例，展示了该控制方案的有效性和所提李亚普诺夫函数的较低保守性。

关键词： 多智能体系统；非脆弱采样数据控制；时变延迟；线性矩阵不等式；渐近同步    

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analytical and numerical studies on concrete encased trapezoidally web profiled cold formed steel beams by varying

Divahar RAVI, Aravind Raj PONSUBBIAH, Sangeetha Sreekumar PRABHA, Joanna Philip SARATHA

《结构与土木工程前沿（英文）》 2020年 第14卷 第4期   页码 930-946 doi: 10.1007/s11709-020-0652-1

摘要： Concrete encased with trapezoidally corrugated web profiled cold-formed steel beams are used worldwide to improve resistance toward fire and corrosion, higher load carrying capacity as well as significant increase in the bending stiffness by encasing concrete on the beam portion. The present work gives a detailed description on the experimental, analytical and numerical investigation on the flexural behavior of concrete encased trapezoidally corrugated web profiled cold-formed steel beams which were simply supported at both ends and subjected to two point symmetric loading. The flexural behavior of such structure has been experimentally tested to failure under pure bending. To find the effect of concrete encasement in the web, 12 experiments were conducted by two different series. Beams having three different web corrugation angles of 0°, 30°, and 45° with two different web depth-thickness ( / ) ratios of 60 and 80 were tested. Experimental results such as load-deflection relationship, ultimate capacity, load-strain relationship, moment-curvature curves, ductility and failure mode indices of the specimens are presented. From the static bending tests the concrete encased trapezoidally corrugated web beam showed improved moment carrying capacity, ductility behavior and the resistance to transverse deflections in comparison to concrete encased with plain web beam. Especially for the beams with concrete encased 30° trapezoidally corrugated web having ( / ) ratio 60 and 80, the loading capacity was improved about 54% and 67.3% and the ductility also increased about 1.6 and 3.6 times, when compared to concrete encased beams with plain web. This research should contribute to the future engineering applications on seismic resistant structures and efficient usage of concrete encased with cold-formed steel beams by exhibiting its super elasto-plastic property. The analytical and numerical results showed good agreement with the experimental results at yield load, which indicates that the proposed analytical equations can be applied in predicting flexural strength accurately for such concrete encased trapezoidally corrugated web profiled cold-formed steel beams.

关键词： concrete encased beam     trapezoidally corrugated web     loading capacity     super elasto-plastic    

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标题 作者 时间 类型 操作

The role delegation authorization model of a computer-supported cooperative design system

XU Hongxue, LIU Yongxian, SHENG Zhongqi, GUO Xiuying

期刊论文

Time-varying formation tracking for uncertain second-order nonlinearmulti-agent systems

Mao-peng RAN, Li-hua XIE, Jun-cheng LI

期刊论文

A multiscale-contour-based interpolation framework for generating a time-varying quasi-dense point cloud

Chu-hua HUANG,Dong-ming LU,Chang-yu DIAO

期刊论文

Position-varying surface roughness prediction method considering compensated acceleration in milling

期刊论文

Attuned design of demand response program and M-FACTS for relieving congestion in a restructured market environment

Y. HASHEMI,H. SHAYEGHI,B. HASHEMI

期刊论文

Elastic analysis of heterogeneous thick-walled spherical pressure vessels with parabolic varying properties

Keyhan KARAMI, Majid ABEDI, Mohammad ZAMANI NEJAD, Mohammad Hassan LOTFIAN

期刊论文

Effects of time-varying liquid bridge forces on rheological properties, and resulting extrudability and

期刊论文

Experimental research on seismic behavior of recycled concrete frame under varying cyclic loading

SUN Yuedong, XIAO Jianzhuang, ZHOU Deyuan

期刊论文

reference tracking control design for a class of nonlinear systems with time-varying delays

Mei-qin LIU,Hai-yang CHEN,Sen-lin ZHANG

期刊论文

Predicting the response of continuous RC deep beams under varying levels of differential settlement

M. Z. NASER, R. A. HAWILEH

期刊论文

一种工业过程时变参数估计新算法——修正目标函数法

张承慧

期刊论文

时变网络的收敛性及其应用

王庆领

期刊论文

Control of peak pressures of an HCCI engine under varying swirl and operating parameters

T. KARTHIKEYA SHARMA,G. AMBA PRASAD RAO,K. MADHU MURTHY

期刊论文

基于非脆弱采样数据控制的非线性多智能体系统同步控制及其在电路系统中的应用

Stephen AROCKIA SAMY1,Raja RAMACHANDRAN2,Pratap ANBALAGAN3,曹阳4

期刊论文

analytical and numerical studies on concrete encased trapezoidally web profiled cold formed steel beams by varying

Divahar RAVI, Aravind Raj PONSUBBIAH, Sangeetha Sreekumar PRABHA, Joanna Philip SARATHA

期刊论文