资源类型

期刊论文 212

会议信息 11

会议视频 1

年份

2023 12

2022 9

2021 16

2020 9

2019 15

2018 21

2017 18

2016 8

2015 9

2014 13

2013 13

2012 11

2011 6

2010 4

2009 10

2008 13

2007 12

2006 6

2005 2

2004 3

展开 ︾

关键词

动力学 2

多输入多输出 2

2

生物材料 2

CDMA 1

CP);符号间干扰(inter symbol interference, ISI);载波间干扰(inter carrier interference 1

GDP 1

GPS 1

HeNe激光器 1

ICI);最大似然估计(maximum likelihood estimation 1

ISO 18186 1

KTP 1

LM331型电压-频率转换器 1

MLE) 1

OFDM);快速傅立叶变换(Fast Fourier transform, FFT);循环前缀(cyclic prefix 1

PID控制 1

P波 1

QRS-T复合波 1

RLC网络;谐振性质;振荡特性;幅频特性 1

展开 ︾

检索范围:

排序: 展示方式:

Probabilistic safety assessment of self-centering steel braced frame

Navid RAHGOZAR, Nima RAHGOZAR, Abdolreza S. MOGHADAM

《结构与土木工程前沿(英文)》 2018年 第12卷 第1期   页码 163-182 doi: 10.1007/s11709-017-0384-z

摘要: The main drawback of conventional braced frames is implicitly accepting structural damage under the design earthquake load, which leads to considerable economic losses. Controlled rocking self-centering system as a modern low-damage system is capable of minimizing the drawbacks of conventional braced frames. This paper quantifies main limit states and investigates the seismic performance of self-centering braced frame using a Probabilistic Safety Assessment procedure. Margin of safety, confidence level, and mean annual frequency of the self-centering archetypes for their main limit states, including PT yield, fuse fracture, and global collapse, are established and are compared with their acceptance criteria. Considering incorporating aleatory and epistemic uncertainties, the efficiency of the system is examined. Results of the investigation indicate that the design of low- and mid-rise self-centering archetypes could provide the adequate margin of safety against exceeding the undesirable limit-states.

关键词: self-centering steel braced frame     mean annual frequency     safety assessment     confidence level     margin of safety    

Corrigendum to “Multidecadal Trends in Large-Scale Annual Mean SATa Based on CMIP5 Historical Simulations Corrigendum

Nan Xing,Jianping Li,Lanning Wang

《工程(英文)》 2017年 第3卷 第3期   页码 428-428 doi: 10.1016/J.ENG.2017.03.015

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

《能源前沿(英文)》 2014年 第8卷 第1期   页码 41-48 doi: 10.1007/s11708-013-0292-4

摘要: Narrow-band transmissivities in the spectral range of 150 to 9300 cm and at a uniform resolution of 25 cm were calculated using the statistical narrow-band (SNB) model with the band parameters of Soufiani and Taine, the more recent parameters of André and Vaillon, and the line-by-line (LBL) method along with the HITEMP-2010 spectroscopic database. Calculations of narrow-band transmissivity were conducted for gas columns of different lengths and containing different isothermal and non-isothermal CO -H O-N mixtures at 1 atm. Narrow-band transmissivities calculated by the SNB model are in large relative error at many bands. The more recent SNB model parameters of André and Vaillon are more accurate than the earlier parameters of Soufiani and Taine. The Planck mean absorption coefficients of CO , H O, CO, and CH in the temperature range of 300 to 2500 K were calculated using the LBL method and different versions of the high resolution transmission (HITRAN) and high-temperature spectroscopic absorption parameters (HITEMP) spectroscopic databases. The SNB model was also used to calculate the Planck mean absorption coefficients of these four radiating gases. The LBL results of the Planck mean absorption coefficient were compared with the classical results of Tien and those from the SNB model.

关键词: transimissity     HITEMP     HITRAN     Planck mean absorption coefficients    

CMIP5 模式对大尺度年平均地面气温异常的多年代际趋势的模拟评估和未来预估

邢楠, 李建平, 王兰宁

《工程(英文)》 2017年 第3卷 第1期   页码 136-143 doi: 10.1016/J.ENG.2016.04.011

摘要:

基于观测和第五次耦合模式比较计划(CMIP5) 模式的模拟结果,本文对全球、半球、半球陆地及海洋尺度的年平均地面气温异常在过去一百多年及两个代表性浓度路径(RCPs) 情景下的多年代际变化及趋势进行了评估分析。根据模式对全球平均地面气温异常的时间变率、长期趋势、多年代际变化及趋势的模拟能力,筛选出15 个模式进行分析。观测结果表明,北半球陆地、北半球海洋和南半球海洋平均地面气温异常与全球平均地面气温异常具有相似的多年代际变化特征:在1900—1944 年及1971—2000 年呈现增暖趋势,并在1945—1970 年和2001—2013 年呈现增暖停滞甚至变冷趋势。模式能够基本再现以上观测特征。然而,与以上变化不同的是,南半球陆地的平均地面气温在1945—1970 年呈现增暖趋势,并且模式不能很好模拟该特征。对于近期的增暖停滞阶段(2001—2013 年),BCC-CSM1-1-m 模式、CMCC-CM 模式、GFDL-ESM2M 模式及NorESM1-ME模式在RCP4.5 和RCP8.5 情景下预估的全球及半球尺度的地面气温异常趋势值最接近观测值,表明它们具有较好的预估能力。由于这四个模式在地面气温异常的多年代际趋势上具有较好的模拟及预估性能,故选择它们来预估2006—2099 年的地面气温异常在全球及半球尺度上的变化特征。结果显示在RCP4.5(RCP8.5) 情景下,所选四个模式集合平均的全球、北半球及南半球年平均地面气温异常趋势值分别为0.17(0.29)、0.22(0.36) 及0.11(0.23) °C•decade–1,其趋势值明显小于未经过模式筛选的CMIP5 模式集合的结果。

关键词: 地面气温异常     多年代际趋势     第五次耦合模式比较计划(CMIP5)     预估    

A job-insertion heuristic for minimizing the mean flowtime in dynamic flowshops

Guang GUO, Bo WU, Shuzi YANG

《机械工程前沿(英文)》 2011年 第6卷 第2期   页码 197-202 doi: 10.1007/s11465-011-0211-5

摘要:

A new adaptive job-insertion based heuristic is presented to minimize the mean flowtime in a dynamic flowshop consisting of machines. Job orders arrive to the system randomly, and the job arrival or release dates are not known in advance. The heuristic is derived by inserting new jobs into the scheduled sequence as needed when the machine becomes free. Computation results indicate that the proposed heuristic performs 2.7%–10.8% better than the SPT dispatching rule, which is currently one of the most effective methods for minimizing the mean flowtime in dynamic flowshops.

关键词: scheduling     dynamic flowshops     flowtime     heuristic     mean flowtime    

Theoretical prediction and validation of global horizontal solar irradiance for a tropical climate in India

Sivasankari SUNDARAM,Jakka SARAT CHANDRA BABU

《能源前沿(英文)》 2015年 第9卷 第3期   页码 311-321 doi: 10.1007/s11708-015-0369-3

摘要: This paper aims to propose monthly models responsible for the theoretical evaluation of the global horizontal irradiance of a tropical region in India which is Sivagangai situated in Tamilnadu. The actual measured global horizontal irradiance hails from a 5 MW solar power plant station located at Sivagangai in Tamilnadu. The data were monitored from May 2011 to April 2013. The theoretical assessment was conducted differently by employing a programming platform called Microsoft Visual Basic 2010 Express. A graphical user interface was created using Visual Basic 2010 Express, which provided the evaluation of empirical parameters for model formulation such as daily sunshine duration ( ), maximum possible sunshine hour duration ( ), extra terrestrial horizontal global irradiance ( ) and extra terrestrial direct normal irradiance ( ). The proposed regression models were validated by the significance of statistical indicators such as mean bias error, root mean square error and mean percentage error from the predicted and the actual values for the region considered. Comparison was made between the proposed monthly models and the existing normalized models for global horizontal irradiance evaluation.

关键词: global horizontal irradiance (GHI)     mean bias error     root mean square error     mean percentage error     coefficient of regression     Visual Basic 2010 Express    

Some remarks on the engineering application of the fatigue crack growth approach under nonzero mean loads

Jorge Alberto Rodriguez DURAN,Ronney Mancebo BOLOY,Rafael Raider LEONI

《机械工程前沿(英文)》 2015年 第10卷 第3期   页码 255-262 doi: 10.1007/s11465-015-0342-1

摘要:

The well-known fatigue crack growth (FCG) curves are two-parameter dependents. The range of the stress intensity factor ?K and the load ratio R are the parameters normally used for describing these curves. For engineering purposes, the mathematical representation of these curves should be integrated between the initial and final crack sizes in order to obtain the safety factors for stresses and life. First of all, it is necessary to reduce the dependence of the FCG curves to only one parameter. ?K is almost always selected and, in these conditions, considered as the crack driving force. Using experimental data from literature, the present paper shows how to perform multiple regression analyses using the traditional Walker approach and the more recent unified approach. The correlations so obtained are graphically analyzed in three dimensions. Numerical examples of crack growth analysis for cracks growing under nominal stresses of constant amplitude in smooth and notched geometries are performed, assuming an identical material component as that of the available experimental data. The resulting curves of crack size versus number of cycles (a vs. N) are then compared. The two models give approximately the same (a vs. N) curves in both geometries. Differences between the behaviors of the (avs. N) curves in smooth and notched geometries are highlighted, and the reasons for these particular behaviors are discussed.

关键词: fatigue crack propagation modeling     life prediction     mean stress effects    

Observer design for induction motor: an approach based on the mean value theorem

Mohamed Yacine HAMMOUDI,Abdelkarim ALLAG,Mohamed BECHERIF,Mohamed BENBOUZID,Hamza ALLOUI

《能源前沿(英文)》 2014年 第8卷 第4期   页码 426-433 doi: 10.1007/s11708-014-0314-x

摘要: In this paper, observer design for an induction motor has been investigated. The peculiarity of this paper is the synthesis of a mono-Luenberger observer for highly coupled system. To transform the nonlinear error dynamics for the induction motor into the linear parametric varying (LPV) system, the differential mean value theorem combined with the sector nonlinearity transformation has been used. Stability conditions based on the Lyapunov function lead to solvability of a set of linear matrix inequalities. The proposed observer guarantees the global exponential convergence to zero of the estimation error. Finally, the simulation results are given to show the performance of the observer design.

关键词: observer design     differential mean value theorem (DMVT)     sector nonlinearity transformation     linear matrix inequalities (LMI)     induction motor    

分层空时码多载波CDMA的译码与检测

杨洁,酆广增

《中国工程科学》 2007年 第9卷 第1期   页码 58-62

摘要:

研究V-BLAST MIMO MC-CDMA下行系统。提出了一种对每个子载波进行V-BLAST译码的非线性 算法,对不同天线数、用户数情况进行了系统的仿真和分析,并对V-BLAST译码的线性和非线性算法进行了系 统仿真比较。

关键词: 多输入多输出     正交频分复用     分层空时码     迫零算法     最小均方误差    

Mean wind load induced incompatibility in nonlinear aeroelastic simulations of bridge spans

Zhitian ZHANG

《结构与土木工程前沿(英文)》 2019年 第13卷 第3期   页码 605-617 doi: 10.1007/s11709-018-0499-x

摘要: Mean wind response induced incompatibility and nonlinearity in bridge aerodynamics is discussed, where the mean wind and aeroelastic loads are applied simultaneously in time domain. A kind of incompatibility is found during the simultaneous simulation of the mean wind and aeroelastic loads, which leads to incorrect mean wind structural responses. It is found that the mathematic expectations (or limiting characteristics) of the aeroelastic models are fundamental to this kind of incompatibility. In this paper, two aeroelastic models are presented and discussed, one of indicial-function-denoted (IF-denoted) and another of rational-function-denoted (RF-denoted). It is shown that, in cases of low wind speeds, the IF-denoted model reflects correctly the mean wind load properties, and results in correct mean structural responses; in contrast, the RF-denoted model leads to incorrect mean responses due to its nonphysical mean properties. At very high wind speeds, however, even the IF-denoted model can lead to significant deviation from the correct response due to steady aerodynamic nonlinearity. To solve the incompatibility at high wind speeds, a methodology of subtraction of pseudo-steady effects from the aeroelastic model is put forward in this work. Finally, with the method presented, aeroelastic nonlinearity resulted from the mean wind response is investigated at both moderate and high wind speeds.

关键词: bridge     aerodynamics     nonlinear     aeroelastic model     Pseudo-steady     mean wind loads    

Classical state feedback controller for nonlinear systems using mean value theorem: closed loop-FOC of

Abrar ALLAG,Abdelhamid BENAKCHA,Meriem ALLAG,Ismail ZEIN,Mohamed Yacine AYAD

《能源前沿(英文)》 2015年 第9卷 第4期   页码 413-425 doi: 10.1007/s11708-015-0379-1

摘要: The problem of state feedback controllers for a class of Takagi-Sugeno (T-S) Lipschitz nonlinear systems is investigated. A simple systematic and useful synthesis method is proposed based on the use of the differential mean value theorem (DMVT) and convex theory. The proposed design approach is based on the mean value theorem (MVT) to express the nonlinear error dynamics as a convex combination of known matrices with time varying coefficients as linear parameter varying (LPV) systems. Using the Lyapunov theory, stability conditions are obtained and expressed in terms of linear matrix inequalities (LMIs). The controller gains are then obtained by solving linear matrix inequalities. The effectiveness of the proposed approach for closed loop-field oriented control (CL-FOC) of permanent magnet synchronous machine (PMSM) drives is demonstrated through an illustrative simulation for the proof of these approaches. Furthermore, an extension for controller design with parameter uncertainties and perturbation performance is discussed.

关键词: Takagi-Sugeno (T-S) fuzzy systems     sector nonlinearity     nonlinear controller     linear matrix inequality (LMI) approach     differential mean value theorem (DMVT)     field oriented control (FOC)     linear parameter varying (LPV)    

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0006-x

摘要: A frequency error estimation is presented for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells using both quadratic and cubic basis functions. By analyzing the discrete isogeometric equations with the aid of harmonic wave assumption, the frequency error measures are rationally derived for the quadratic and cubic formulations for Kirchhoff–Love cylindrical shells. In particular, the governing relationship of the continuum frequency for Kirchhoff–Love cylindrical shells is naturally embedded into the frequency error measures without the need of explicit frequency expressions, which usually are not trivial for the shell problems. In accordance with these theoretical findings, the 2nd and 4th orders of frequency accuracy are attained for the isogeometric schemes using quadratic and cubic basis functions, respectively. Numerical results not only thoroughly verify the theoretical convergence rates of frequency solutions, but also manifest an excellent magnitude match between numerical and theoretical frequency errors for the isogeometric free vibration analysis of Kirchhoff–Love cylindrical shells.

关键词: isogeometric analysis     Kirchhoff–Love cylindrical shell     free vibration     frequency error     convergence    

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and gas explosion

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

《结构与土木工程前沿(英文)》 2018年 第12卷 第3期   页码 425-437 doi: 10.1007/s11709-017-0427-5

摘要:

In recent decades, many public buildings, located in seismic-prone residential areas, had to grapple with abnormal loads against which the structures were unguarded. In this piece of research, an ordinary three dimensional reinforced concrete building is selected as case study. The building is located in an earthquake-prone region; however, it is designed according to seismic building codes. Yet, it is not shielded against abnormal loads, such as blasts. It is assumed that the building suffers a blast load, due to mechanical/thermal installation failure during or after intense seismic oscillations. These two critical incidents are regarded codependent and compatible. So the researchers developed scenarios and tried to assess different probabilities for each scenario and carried out an analysis to ensure if progressive collapse had set in or not. In the first step, two analysis models were used for each scenario; a non-linear dynamic time history analysis and a blast local dynamic analysis. In the second step, having the structural destructions of the first step in view, a pushdown analysis was carried out to determine the severity of progressive collapse and assess building robustness. Finally, the annual probability of structural collapse under simultaneous earthquake and blast loads was estimated and offered.

关键词: gas blast     pushdown analysis     progressive collapse     annual probability of structural collapse     3D model of structure    

Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough receiver

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

《能源前沿(英文)》 2020年 第14卷 第4期   页码 867-881 doi: 10.1007/s11708-020-0707-y

摘要: This paper proposes a comprehensive thermodynamic and economic model to predict and compare the performance of concentrated solar power plants with traditional and novel receivers with different configurations involving operating temperatures and locations. The simulation results reveal that power plants with novel receivers exhibit a superior thermodynamic and economic performance compared with traditional receivers. The annual electricity productions of power plants with novel receivers in Phoenix, Sevilla, and Tuotuohe are 8.5%, 10.5%, and 14.4% higher than those with traditional receivers at the outlet temperature of 550°C. The levelized cost of electricity of power plants with double-selective-coated receivers can be decreased by 6.9%, 8.5%, and 11.6%. In Phoenix, the optimal operating temperature of the power plants is improved from 500°C to 560°C by employing a novel receiver. Furthermore, the sensitivity analysis of the receiver heat loss, solar absorption, and freeze protection temperature is also conducted to analyze the general rule of influence of the receiver performance on power plants performance. Solar absorption has a positive contribution to annual electricity productions, whereas heat loss and freeze protection temperature have a negative effect on electricity outputs. The results indicate that the novel receiver coupled with low melting temperature molten salt is the best configuration for improving the overall performance of the power plants.

关键词: concentrated solar power     parabolic trough receiver     heat loss     solar energy     annual performance    

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

《能源前沿(英文)》 2013年 第7卷 第4期   页码 506-510 doi: 10.1007/s11708-013-0275-5

摘要: The collision frequency function for aerosol particles has already been calculated for the free molecule regime and for the continuum range. The present work, taking into account the influence of internal force fields such as magnetic force, electric force and molecular forces, created by particles themselves, recalculated the collision frequency in the case of particles much smaller than the mean free path of the gas (free molecule regime). Attractive forces increase naturally the collision frequency, while repulsive forces decrease it. The calculation was performed for all types of central forces deriving from a potential, including Coulomb forces and Van der Waals forces.

关键词: aerosol particles     collision frequency function     coagulation    

标题 作者 时间 类型 操作

Probabilistic safety assessment of self-centering steel braced frame

Navid RAHGOZAR, Nima RAHGOZAR, Abdolreza S. MOGHADAM

期刊论文

Corrigendum to “Multidecadal Trends in Large-Scale Annual Mean SATa Based on CMIP5 Historical Simulations

Nan Xing,Jianping Li,Lanning Wang

期刊论文

Calculations of narrow-band transimissities and the Planck mean absorption coefficients of real gases

Huaqiang CHU, Mingyan GU, Huaichun ZHOU, Fengshan LIU

期刊论文

CMIP5 模式对大尺度年平均地面气温异常的多年代际趋势的模拟评估和未来预估

邢楠, 李建平, 王兰宁

期刊论文

A job-insertion heuristic for minimizing the mean flowtime in dynamic flowshops

Guang GUO, Bo WU, Shuzi YANG

期刊论文

Theoretical prediction and validation of global horizontal solar irradiance for a tropical climate in India

Sivasankari SUNDARAM,Jakka SARAT CHANDRA BABU

期刊论文

Some remarks on the engineering application of the fatigue crack growth approach under nonzero mean loads

Jorge Alberto Rodriguez DURAN,Ronney Mancebo BOLOY,Rafael Raider LEONI

期刊论文

Observer design for induction motor: an approach based on the mean value theorem

Mohamed Yacine HAMMOUDI,Abdelkarim ALLAG,Mohamed BECHERIF,Mohamed BENBOUZID,Hamza ALLOUI

期刊论文

分层空时码多载波CDMA的译码与检测

杨洁,酆广增

期刊论文

Mean wind load induced incompatibility in nonlinear aeroelastic simulations of bridge spans

Zhitian ZHANG

期刊论文

Classical state feedback controller for nonlinear systems using mean value theorem: closed loop-FOC of

Abrar ALLAG,Abdelhamid BENAKCHA,Meriem ALLAG,Ismail ZEIN,Mohamed Yacine AYAD

期刊论文

A frequency error estimation for isogeometric analysis of Kirchhoff–Love cylindrical shells

期刊论文

Proposal of a probabilistic assessment of structural collapse concomitantly subject to earthquake and gas explosion

Gholamreza ABDOLLAHZADEH, Hadi FAGHIHMALEKI

期刊论文

Potential of performance improvement of concentrated solar power plants by optimizing the parabolic trough receiver

Honglun YANG, Qiliang WANG, Jingyu CAO, Gang PEI, Jing LI

期刊论文

Calculation of collision frequency function for aerosol particles in free molecule regime in presence

Xiaowei LUO, Yannick BENICHOU, Suyuan YU

期刊论文