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Estimation of load and resistance factors using the third-moment method based on the 3P-lognormal distribution

Yan-Gang ZHAO, Zhao-Hui LU

《结构与土木工程前沿（英文）》 2011年 第5卷 第3期   页码 315-322 doi: 10.1007/s11709-011-0117-7

摘要： Load and resistance factors are generally obtained using the first order reliability method (FORM) in which the design point should be determined and derivative-based iterations used. In this article, the third-moment reliability index, based on the three-parameter lognormal (3P-lognormal) distribution, is investigated. A simple method based on the third-moment method for estimating load and resistance factors is then proposed, and a simple formula for the target mean resistance is also presented to avoid iterative computations. Unlike the currently used method, the proposed method can be used to determine load and resistance factors, even when the probability density functions (PDFs) of the basic random variables are not available. Moreover, the proposed method does not require the iterative computation of derivatives or any design points. Thus, the method provides a more convenient and effective way to estimate load and resistance factors in practical engineering applications. Numerical examples are presented to demonstrate the advantages of the proposed third moment method for determining load and resistance factors.

关键词： load and resistance factors     third-moment method     three-parameter lognormal (3P-lognormal) distribution     target mean resistance     simple formula    

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High-order moment methods for LRFD including random variables with unknown probability distributions

Zhao-Hui LU, Yan-Gang ZHAO, Zhi-Wu YU

《结构与土木工程前沿（英文）》 2013年 第7卷 第3期   页码 288-295 doi: 10.1007/s11709-013-0210-1

摘要： The reliability-based load and resistance factors design (LRFD) has been widely used in the structural design codes. In almost all of the current reliability methods for the determination of the load and resistance factors, the basic random variables are assumed to have known probability distributions. However, in reality, the probability distributions of some of the basic random variables are often unknown due to the lack of statistical data. In this paper, the high-order moment methods for LRFD including random variables with unknown probability distributions are proposed. From the investigation of the present paper, it can be concluded that: 1) The load and resistance factors can be determined even when the probability distributions of the basic random variables are unknown; 2) The present method is convenient and more effective in estimating the load and resistance factors in practical engineering since it needs neither the iterative computation of derivatives nor any design points; 3) In the applicable range of the high-order moment method, although the load and resistance factors obtained by the proposed method may be different from those obtained by first order reliability method (FORM), the target mean resistances obtained by both methods are essentially the same.

关键词： high-order moment methods     applicable range     load and resistance factors     target mean resistance    

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mTOR-targeted cancer therapy: great target but disappointing clinical outcomes, why?

Shi-Yong Sun

《医学前沿（英文）》 2021年 第15卷 第2期   页码 221-231 doi: 10.1007/s11684-020-0812-7

摘要： The mammalian target of rapamycin (mTOR) critically regulates several essential biological functions, such as cell growth, metabolism, survival, and immune response by forming two important complexes, namely, mTOR complex 1 (mTORC1) and complex 2 (mTORC2). mTOR signaling is often dysregulated in cancers and has been considered an attractive cancer therapeutic target. Great efforts have been made to develop efficacious mTOR inhibitors, particularly mTOR kinase inhibitors, which suppress mTORC1 and mTORC2; however, major success has not been achieved. With the strong scientific rationale, the intriguing question is why cancers are insensitive or not responsive to mTOR-targeted cancer therapy in clinics. Beyond early findings on induced activation of PI3K/Akt, MEK/ERK, and Mnk/eIF4E survival signaling pathways that compromise the efficacy of rapalog-based cancer therapy, recent findings on the essential role of GSK3 in mediating cancer cell response to mTOR inhibitors and mTORC1 inhibition-induced upregulation of PD-L1 in cancer cells may provide some explanations. These new findings may also offer us the opportunity to rationally utilize mTOR inhibitors in cancer therapy. Further elucidation of the biology of complicated mTOR networks may bring us the hope to develop effective therapeutic strategies with mTOR inhibitors against cancer.

关键词： mTOR     cancer therapy     resistance     GSK3     protein degradation     E3 ubiquitin ligase     PD-L1    

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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    

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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    

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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    

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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    

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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    

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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    

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Multi-target combinatory strategy to overcome tumor immune escape

《医学前沿（英文）》 2022年 第16卷 第2期   页码 208-215 doi: 10.1007/s11684-022-0922-5

摘要： Immune therapy has become the fourth approach after surgery, chemotherapy, and radiotherapy in cancer treatment. Many immune checkpoints were identified in the last decade since ipilimumab, which is the first immune checkpoint inhibitor to cytotoxic T-lymphocyte associated protein 4, had been approved by the US Food and Drug Administration (FDA) for the treatment of unresectable or metastatic melanoma in 2011. The use of several antibody drugs that target PD1/PD-L1 for various cancer treatments has been approved by the FDA. However, fewer people are benefitting from immune checkpoint inhibitor treatment in solid cancers. Approximately 80% of patients do not respond appropriately because of primary or acquired therapeutic resistance. Along with the characterization of more immune checkpoints, the combinatory treatment of multi-immune checkpoint inhibitors becomes a new option when monotherapy could not receive a good response. In this work, the author focuses on the combination therapy of multiple immune checkpoints (does not include targeted therapy of oncogenes or chemotherapy), introduces the current progression of multiple immune checkpoints and their related inhibitors, and discusses the advantages of combination therapy, as well as the risk of immune-related adverse events.

关键词： immune checkpoints     multi-target     immune escape     immune-related adverse events     combination therapy    

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Atypical pituitary hormone–target tissue axis

《医学前沿（英文）》 2023年 第17卷 第1期   页码 1-17 doi: 10.1007/s11684-022-0973-7

摘要： A long-held belief is that pituitary hormones bind to their cognate receptors in classical target glands to actuate their manifold functions. However, a number of studies have shown that multiple types of pituitary hormone receptors are widely expressed in non-classical target organs. Each pituitary gland-derived hormone exhibits a wide range of nonconventional biological effects in these non-classical target organs. Herein, the extra biological functions of pituitary hormones, thyroid-stimulating hormone, follicle-stimulating hormone, luteinizing hormone, adrenocorticotrophic hormone, and prolactin when they act on non-classical organs were summarized, defined by the novel concept of an “atypical pituitary hormone–target tissue axis.” This novel proposal explains the pathomechanisms of abnormal glucose and lipid metabolism, obesity, hypertension, fatty liver, and atherosclerosis while offering a more comprehensive and systematic insights into the coordinated regulation of environmental factors, genetic factors, and neuroendocrine hormones on human biological functions. The continued exploration of the physiology of the “atypical pituitary hormone–target tissue axis” could enable the identification of novel therapeutic targets for metabolic diseases.

关键词： thyroid-stimulating hormone     follicle-stimulating hormone     luteinizing hormone     adrenocorticotrophic hormone     prolactin    

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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)    

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Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma

null

《医学前沿（英文）》 2016年 第10卷 第1期   页码 52-60 doi: 10.1007/s11684-016-0433-3

摘要：

Hepatocellular carcinoma (HCC) is a lethal liver malignancy worldwide. In this study, we reported that protein phosphatase magnesium-dependent 1δ (PPM1D) was highly expressed in the majority of HCC cases (approximately 59%) and significantly associated with high serum α-fetoprotein (AFP) level (P= 0.044). Kaplan-Meier and Cox regression data indicated that PPM1D overexpression was an independent predictor of HCC-specific overall survival (HR, 2.799; 95% CI, 1.346–5.818, P = 0.006). Overexpressing PPM1D promoted cell viability and invasion, whereas RNA interference-mediated knockdown of PPM1D inhibited proliferation, invasion, and migration of cultured HCC cells. In addition, PPM1D suppression by small interfering RNA decreased the tumorigenicity of HCC cells in vivo. Overall, results suggest that PPM1D is a potential prognostic marker and therapeutic target for HCC.

关键词： PPM1D     hepatocellular carcinoma     prognosis     target therapy    

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Amodified variable rate particle filter for maneuvering target tracking

Yun-fei GUO,Kong-shuai FAN,Dong-liang PENG,Ji-an LUO,Han SHENTU

《信息与电子工程前沿（英文）》 2015年 第16卷 第11期   页码 985-994 doi: 10.1631/FITEE.1500149

摘要： To address the problem of maneuvering target tracking, where the target trajectory has prolonged smooth regions and abrupt maneuvering regions, a modified variable rate particle filter (MVRPF) is proposed. First, a Cartesian-coordinate based variable rate model is presented. Compared with conventional variable rate models, the proposed model does not need any prior knowledge of target mass or external forces. Consequently, it is more convenient in practical tracking applications. Second, a maneuvering detection strategy is adopted to adaptively adjust the parameters in MVRPF, which helps allocate more state points at high maneuver regions and fewer at smooth regions. Third, in the presence of small measurement errors, the unscented particle filter, which is embedded in MVRPF, can move more particles into regions of high likelihood and hence can improve the tracking performance. Simulation results illustrate the effectiveness of the proposed method.

关键词： Maneuvering target tracking     Prolonged smooth regions     Variable rate model     Maneuver detection    

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Prevalence of antifolate drug resistance markers in in China

《医学前沿（英文）》 2022年 第16卷 第1期   页码 83-92 doi: 10.1007/s11684-021-0894-x

摘要： The dihydrofolate reductase (dhfr) and dihydropteroate synthetase (dhps) genes of Plasmodium vivax and antifolate resistance-associated genes were used for drug resistance surveillance. A total of 375 P. vivax isolates collected from different geographical locations in China in 2009–2019 were used to sequence Pvdhfr and Pvdhps. The majority of the isolates harbored a mutant type allele for Pvdhfr (94.5%) and Pvdhps (68.2%). The most predominant point mutations were S117T/N (77.7%) in Pvdhfr and A383G (66.8%) in Pvdhps. Amino acid changes were identified at nine residues in Pvdhfr. A quadruple-mutant haplotype at 57, 58, 61, and 117 was the most frequent (57.4%) among 16 distinct Pvdhfr haplotypes. Mutations in Pvdhps were detected at six codons, and the double-mutant A383G/A553G was the most prevalent (39.3%). Pvdhfr exhibited a higher mutation prevalence and greater diversity than Pvdhps in China. Most isolates from Yunnan carried multiple mutant haplotypes, while the majority of samples from temperate regions and Hainan Island harbored the wild type or single mutant type. This study indicated that the antifolate resistance levels of P. vivax parasites were different across China and molecular markers could be used to rapidly monitor drug resistance. Results provided evidence for updating national drug policy and treatment guidelines.

关键词： drug resistance     antifolates     molecular markers     Plasmodium vivax     China    

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标题 作者 时间 类型 操作

Estimation of load and resistance factors using the third-moment method based on the 3P-lognormal distribution

Yan-Gang ZHAO, Zhao-Hui LU

期刊论文

High-order moment methods for LRFD including random variables with unknown probability distributions

Zhao-Hui LU, Yan-Gang ZHAO, Zhi-Wu YU

期刊论文

mTOR-targeted cancer therapy: great target but disappointing clinical outcomes, why?

Shi-Yong Sun

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

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

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

Zhitian ZHANG

期刊论文

Multi-target combinatory strategy to overcome tumor immune escape

期刊论文

Atypical pituitary hormone–target tissue axis

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

Protein phosphatase magnesium-dependent 1δ is a novel tumor marker and target in hepatocellular carcinoma

null

期刊论文

Amodified variable rate particle filter for maneuvering target tracking

Yun-fei GUO,Kong-shuai FAN,Dong-liang PENG,Ji-an LUO,Han SHENTU

期刊论文

Prevalence of antifolate drug resistance markers in in China

期刊论文