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Accounting for the uncertainties in the estimation of average shear wave velocity using – correlations

《结构与土木工程前沿（英文）》 2021年 第15卷 第5期   页码 1199-1208 doi: 10.1007/s11709-021-0749-1

摘要： Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures, particularly in seismically active regions. Shear wave velocity ( V S) is a key parameter in such analysis, although the economy and other factors restrict its direct field measurement in many cases. Various V S–SPT– N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V S. However, many uncertainties question the reliability of these estimated V S values. This paper comes up with a statistical approach to take care of such uncertainties involved in V S calculations. The measured SPT– N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V S at different depths. The effect of different soil layers in the boreholes on the Vs estimation was also taken into account. Further, the average shear wave velocity of the top 30 m soil cover ( V S30) is estimated after accounting for various epistemic and aleatoric uncertainties. The scattering nature of the V S values estimated using different V S– N correlations was reduced significantly with the application of the methodology. Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V S30 using general and soil-specific correlations.

关键词： uncertainties     V S– N correlations     V S30     SPT data     statistical methodology    

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Applicability of high dimensional model representation correlations for ignition delay times of n-heptane

Wang LIU, Jiabo ZHANG, Zhen HUANG, Dong HAN

《能源前沿（英文）》 2019年 第13卷 第2期   页码 367-376 doi: 10.1007/s11708-018-0584-9

摘要： It is difficult to predict the ignition delay times for fuels with the two-stage ignition tendency because of the existence of the nonlinear negative temperature coefficient (NTC) phenomenon at low temperature regimes. In this paper, the random sampling-high dimensional model representation (RS-HDMR) methods were employed to predict the ignition delay times of n-heptane/air mixtures, which exhibits the NTC phenomenon, over a range of initial conditions. A detailed n-heptane chemical mechanism was used to calculate the fuel ignition delay times in the adiabatic constant-pressure system, and two HDMR correlations, the global correlation and the stepwise correlations, were then constructed. Besides, the ignition delay times predicted by both types of correlations were validated against those calculated using the detailed chemical mechanism. The results showed that both correlations had a satisfactory prediction accuracy in general for the ignition delay times of the n-heptane/air mixtures and the stepwise correlations exhibited a better performance than the global correlation in each subdomain. Therefore, it is concluded that HDMR correlations are capable of predicting the ignition delay times for fuels with two-stage ignition behaviors at low-to-intermediate temperature conditions.

关键词： ignition delay     random sampling     high dimensional model representation     n-heptane     fuel kinetics    

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Etiology of invasive candidosis agents in Russia: a multicenter epidemiological survey

null

《医学前沿（英文）》 2018年 第12卷 第1期   页码 84-91 doi: 10.1007/s11684-017-0612-x

摘要：

A multicenter prospective epidemiological survey on the etiologic agents of invasive candidosis was conducted in Russia in the period of 2012–2014. Samples were collected from 284 patients with invasive candidosis and Candida species isolated by culture. The species were identified by DNA sequencing and MALDI-TOF mass-spectrometry. A total of 322 isolates were recovered, in which 96% of Сandida species belonged to six major species, namely, C. albicans (43.2%), C. parapsilosis (20.2%), C. glabrata (11.5%), C. tropicalis (9.6%), C. krusei (6.2%), and C. guilliermondii (5.3%). Most Candida species were isolated from blood samples (83.23%). Notably, the prevalence rate of C. albicans reduced from 52.38% to 32.79% (2012 vs. 2014) (P=0.01) whereas that of non-C. albicans increased from 47.62% (2012) to 67.21% (2014) (P<0.01). Species distribution differed among geographical regions; specifically, the prevalence rate of C. albicans as an etiologic agent of invasive candidosis in Siberian Federal region was significantly higher than that in other Federal regions. Results indicated a shift from C. albicans to non-C. albicans. Therefore, a detailed investigation on the contributing factors and appropriate treatment of invasive candidosis is needed.

关键词： prevalence     &Scy     andida species     invasive candidosis     nosocomial     etiology     MALDI-TOF mass-spectrometry     candidemia    

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Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

《工程管理前沿（英文）》 2018年 第5卷 第4期   页码 499-506 doi: 10.15302/J-FEM-2018031

摘要：

This work is devoted to the problem of planning of freight railway transportation. We define a special conflict graph on the basis of a set of acceptable train routes. The investigation aims to solve the classical combinatorial optimization problem in relation to the maximum independent set of vertices in undirected graphs. The level representation of the graph and its tree are introduced. With use of these constructions, the lower and upper bounds for the number of vertices in the maximum independent set are obtained.

关键词： independent set     algorithm     planning of transportation     two-sided estimate    

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Non-thermal plasma for exhaust gases treatment

,Arturo COLÍN C.,Víctor SÁNCHEZ-MENDIETA,Ricardo VALDIVIA B.,Alfredo SANTANA D.,José HUERTAS C.

《机械工程前沿（英文）》 2015年 第10卷 第3期   页码 301-305 doi: 10.1007/s11465-015-0344-z

摘要：

This article describes a study on a non-thermal plasma device to treat exhaust gases in an internal combustion engine. Several tests using a plasma device to treat exhaust gases are conducted on a Honda GX200-196 cm3 engine at different rotational speeds. A plasma reactor could be efficient in degrading nitrogen oxides and particulate matter. Monoxide and carbon dioxide treatment is minimal. However, achieving 1%–3% degradation may be interesting to reduce the emission of greenhouse gases.

关键词： plasma treatment     NOx     CO     CO2     particulate matter     vehicle    

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Effect of exhaust gas recirculation and ethyl hexyl nitrate additive on biodiesel fuelled diesel engine for the reduction of NO

S. R MURTHY, V. V. SUBBARAO, K. Vijaya KUMAR

《能源前沿（英文）》 2012年 第6卷 第3期   页码 304-310 doi: 10.1007/s11708-012-0195-9

摘要： Cetane improvers reduce the ignition delay, which in turn reduces the combustion temperatures thereby reduce NO emissions. Exhaust gas recirculation (EGR) proved to be an effective way to reduce the NO emissions. In this present experimental work, a combination of exhaust gas recirculation and cetane improver ethyl hexyl nitrate (EHN) is used to investigate the performance and exhaust emissions of a single cylinder four stroke naturally aspirated direct injection and air cooled diesel engine. Test results show that the brake thermal efficiency increases with the increase in the percentage of EGR which is accompanied by a reduction in brake specific fuel consumption and exhaust gas temperatures, and that bio-diesel with cetane improver under 20% EGR reduces NO emissions by 33% when compared to baseline fuel without EGR. However carbon monoxide (CO), hydro carbon (HC) and smoke emissions increase with an increase in percentage of EGR.

关键词： additive     exhaust gas recirculation (EGR)     emissions     ethyl hexyl nitrate (EHN)     performance    

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Real time monitoring for analysis of dam stability: Potential of nonlinear elasticity and nonlinear dynamics approaches

MATCHARASHVILI, V. ABASHIDZE, M. KALABEGISHVILI, N. ZHUKOVA

《结构与土木工程前沿（英文）》 2013年 第7卷 第2期   页码 188-205 doi: 10.1007/s11709-013-0199-5

摘要： Large dams are complex structures with nonlinear dynamic behavior. Engineers often are forced to assess dam safety based on the available incomplete data, which is extremely difficult. This important problem can be solved with the modern theory of complex systems. It is possible to derive characteristics of the whole unknown dynamics of a structure using few data sets of certain carefully selected representative parameter(s). By means of high quality continuous records of some geotechnical characteristic(s) of a dam and modern methods of time series linear/nonlinear analysis the main dynamical features of the entire, unknown process (here—dam deformation) can be analyzed. ?We created the cost-effective Monitoring Telemetric System for Dam Diagnostics (DAMWATCH), which consists of sensors (tiltmeters), terminal and central controllers connected by the GSM/GPRS Modem to the diagnostic center. The tilt data recorded for varying reservoir level are compared with static design model of dam deformations computed by a finite element method (FEM) for the dam-reservoir-foundation system. Besides, recently developed linear/nonlinear data analysis and prediction schemes may help to quantify fine dynamical features of the dam behavior. The software package DAMTOOL has been developed for this purpose. ?The differences between measured and theoretically predicted response parameters of the dam may signal abnormal behavior of the object. The data obtained already by testing of the DAMWATCH/DAMTOOL system during operation of the high Enguri arc dam and reservoir (Georgia) show interesting long-term and short-term patterns of tilts in the dam body, which can be used for dam diagnostics. The proposed real-time telemetric monitoring (DAMWATCH) complex and linear/nonlinear dynamical analysis system (DAMTOOL) are unique.

关键词： real time monitoring     telemetry     dam tilts     diagnostic tools     hysteresis     nonlinear dynamics    

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Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo

S. OHUNAKIN, M. S. ADARAMOLA, O. M. OYEWOLA, R. O. FAGBENLE

《能源前沿（英文）》 2013年 第7卷 第2期   页码 214-222 doi: 10.1007/s11708-013-0241-2

摘要： In this study, the global solar radiation on horizontal surface in Osogbo, Osun state, Nigeria was analyzed using 11-year data (1997–2007). Correlations using linear and quadratic expressions were developed to relate the global solar radiation on horizontal surface based on relative sunshine hours and temperature measurements for evaluating the monthly average daily global solar radiation. The calculated monthly clearness index values indicate that the prevailing weather condition in Osogbo is heavily overcast. All the developed quadratic correlations gave better correlation coefficients (0.834, 0.872 and 0.823 respectively) than the linear models. However, the Hargreaves and Samani related based quadratic model gave the best among the three developed quadratic expressions and is therefore suggested for estimating the monthly global radiation in this site and its surroundings.

关键词： global solar radiation     Hargreaves model     sunshine hour     ambient temperatures     Osogbo    

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Statistical modeling of radiolytic (

S. Muthu Iswarya, B. Nirkayani, A. Kavithakani, V. C. Padmanaban

《环境科学与工程前沿（英文）》 2019年 第13卷 第3期 doi: 10.1007/s11783-019-1126-3

摘要：

Linear, interactive and quadratic effects of process parameters were studied.

Degradation of Ofloxacin (Ofx) was related with G value of irradiation process.

The synergistic effect of H2O2 on lower dose of g-irradiation was established.

The process follows pseudo first order with dose constant (d = 0.232 kGy–1).

关键词： Ofloxacin     Gamma irradiation     Face centered central composite design     Reaction kinetics     Gas Chromatography-Mass spectrum    

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基于动态S-N曲线的飞机结构日历寿命分析

杨晓华,姚卫星,陈跃良

《中国工程科学》 2002年 第4卷 第6期   页码 33-35

摘要：

为科学地确定飞机结构的日历寿命，文章认为飞机结构的损伤历程是地面停放环境和空中疲劳载荷协同作用的结果，并提出了以动态的S-N曲线为基础，采用传统的名义应力法和Miner累积损伤理论来估算结构日历寿命的方法

关键词： 飞机结构     日历寿命     腐蚀     疲劳     S-N曲线    

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用考虑置信区间长度影响的最小二乘法拟合S-N曲线

杨晓华,金平,姚卫星

《中国工程科学》 2004年 第6卷 第4期   页码 41-43

摘要：

S-N曲线是用名义应力法预测结构疲劳寿命的基础。基于试验疲劳寿命分散的物理机制，提出了一个S-N曲线试验数据处理的加权最小二乘法，此方法中每组数据的权重与该组数据的置信区间成反比。计算结果表明用考虑置信区间长度影响的最小二乘法拟合得到的S-N曲线比用一般最小二乘法得到的S-N曲线具有更高的可靠度，给出的寿命预测结果也更安全。

关键词： 置信区间     疲劳寿命     最小二乘法     S-N曲线    

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Fatigue crack growth simulations of 3-D linear elastic cracks under thermal load by XFEM

Himanshu PATHAK,Akhilendra SINGH,I.V. SINGH,S. K. YADAV

《结构与土木工程前沿（英文）》 2015年 第9卷 第4期   页码 359-382 doi: 10.1007/s11709-015-0304-z

摘要： This paper deals with the fatigue crack growth simulations of three-dimensional linear elastic cracks by XFEM under cyclic thermal load. Both temperature and displacement approximations are extrinsically enriched by Heaviside and crack front enrichment functions. Crack growth is modelled by successive linear extensions, and the end points of these linear extensions are joined by cubic spline segments to obtain a modified crack front. Different crack geometries such as planer, non-planer and arbitrary spline shape cracks are simulated under thermal shock, adiabatic and isothermal loads to reveal the sturdiness and versatility of the XFEM approach.

关键词： 3-D cracks     fatigue life     Paris law     thermal load     XFEM    

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A combination of damage locating vector method (DLV) and differential evolution algorithm (DE) for structural damage assessment

TRAN-VIET, N. NGUYEN-MINH, T. VO-DUY, V. HO-HUU

《结构与土木工程前沿（英文）》 2018年 第12卷 第1期   页码 92-108 doi: 10.1007/s11709-016-0379-1

摘要： In this study, a two-stage method is presented for identifying multiple damage scenarios. In the first stage, the damage locating vector (DLV) method using normalized cumulative energy ( ) is employed for damage localization in structures. In the second stage, the differential evolution algorithm (DE) is used for damage severity of the structures. In addition, in the second stage, a modification of an available objective function is made for handing the issue of symmetric structures. To verify the effectiveness of the present technique, numerical examples of a 72-bar space truss and a one-span steel portal frame are considered. In addition, the effect of noise on the performance of the identification results is also investigated. The numerical results show that the proposed combination gives good assessment of damage location and extent for multiple structural damage cases.

关键词： damage assessment     damage locating vector method (DLV)     differential evolution (DE)     multiple damage location assurance criterion (MDLAC)     mode shape error function    

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Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

《结构与土木工程前沿（英文）》 2014年 第8卷 第3期   页码 270-281 doi: 10.1007/s11709-014-0265-7

摘要： Many researches have been carried out to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate by volume, yet there is no specific guideline has been developed on the mix design of the rubbercrete. The experimental program, which has been developed and reported in this paper, is designed and executed to provide such mix design guidelines. A total of 45 concrete mixes with three different water to cement ratio (0.41, 0.57 and 0.68) were cast and tested for fresh and mechanical properties of rubbercrete such as slump, air content, unit weight, compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. Influence of mix design parameters such as percentage of crumb rubber replacement, cement content, water content, fine aggregate content, and coarse aggregate content were investigated. Three levels of slump value (for conventional concrete mixes) has been selected; low, medium and high slump. In each slump level, water content was kept constant. Equations for the reduction factors (RFs) for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity have been developed. These RFs can be used to design rubbercrete mixes based on the conventional mix (0% crumb rubber content)

关键词： crumb rubber     recycled tire     mix design     reduction factor     strength     modulus elasticity    

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Three potential benefits of the EU and IMO’s landmark efforts to monitor carbon dioxide emissions from

Shuaian WANG, Lu ZHEN, Harilaos N. PSARAFTIS

《工程管理前沿（英文）》 2021年 第8卷 第2期   页码 310-311 doi: 10.1007/s42524-020-0096-2

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标题 作者 时间 类型 操作

Accounting for the uncertainties in the estimation of average shear wave velocity using – correlations

期刊论文

Applicability of high dimensional model representation correlations for ignition delay times of n-heptane

Wang LIU, Jiabo ZHANG, Zhen HUANG, Dong HAN

期刊论文

Etiology of invasive candidosis agents in Russia: a multicenter epidemiological survey

null

期刊论文

Maximum independent set in planning freight railway transportation

Gainanov Damir N., Mladenovic NENAD, Rasskazova V. A.

期刊论文

Non-thermal plasma for exhaust gases treatment

,Arturo COLÍN C.,Víctor SÁNCHEZ-MENDIETA,Ricardo VALDIVIA B.,Alfredo SANTANA D.,José HUERTAS C.

期刊论文

Effect of exhaust gas recirculation and ethyl hexyl nitrate additive on biodiesel fuelled diesel engine for the reduction of NO

S. R MURTHY, V. V. SUBBARAO, K. Vijaya KUMAR

期刊论文

Real time monitoring for analysis of dam stability: Potential of nonlinear elasticity and nonlinear dynamics approaches

MATCHARASHVILI, V. ABASHIDZE, M. KALABEGISHVILI, N. ZHUKOVA

期刊论文

Correlations for estimating solar radiation using sunshine hours and temperature measurement in Osogbo

S. OHUNAKIN, M. S. ADARAMOLA, O. M. OYEWOLA, R. O. FAGBENLE

期刊论文

Statistical modeling of radiolytic (

S. Muthu Iswarya, B. Nirkayani, A. Kavithakani, V. C. Padmanaban

期刊论文

基于动态S-N曲线的飞机结构日历寿命分析

杨晓华,姚卫星,陈跃良

期刊论文

用考虑置信区间长度影响的最小二乘法拟合S-N曲线

杨晓华,金平,姚卫星

期刊论文

Fatigue crack growth simulations of 3-D linear elastic cracks under thermal load by XFEM

Himanshu PATHAK,Akhilendra SINGH,I.V. SINGH,S. K. YADAV

期刊论文

A combination of damage locating vector method (DLV) and differential evolution algorithm (DE) for structural damage assessment

TRAN-VIET, N. NGUYEN-MINH, T. VO-DUY, V. HO-HUU

期刊论文

Strength reduction factors for structural rubbercrete

Bashar S. MOHAMMED,N. J. AZMI

期刊论文

Three potential benefits of the EU and IMO’s landmark efforts to monitor carbon dioxide emissions from

Shuaian WANG, Lu ZHEN, Harilaos N. PSARAFTIS

期刊论文