An extended smart driver model considering electronic throttle angle changes with memory

Based on the fact that the electronic throttle angle effect performs well in the traditional car following model,this paper attempts to introduce the electronic throttle angle into the smart driver model(SDM)as an acceleration feedback control term,and establish an extended smart driver model considering electronic throttle angle changes with memory(ETSDM).In order to show the practicability of the extended model,the next generation simulation(NGSIM)data was used to calibrate and evaluate the extended model and the smart driver model.The calibration results show that,compared with SDM,the simulation value based on the ETSDM is better fitted with the measured data,that is,the extended model can describe the actual traffic situation more accurately.Then,the linear stability analysis of ETSDM was carried out theoretically,and the stability condition was derived.In addition,numerical simulations were explored to show the influence of the electronic throttle angle changes with memory and the driver sensitivity on the stability of traffic flow.The numerical results show that the feedback control term of electronic throttle angle changes with memory can enhance the stability of traffic flow,which shows the feasibility and superiority of the proposed model to a certain extent.     

Quantitative analysis of topical gels and ointments by FT-Raman spectroscopy

A method for quantitative determination of ibuprofen (IBU), naproxen (NAP), methyl salicylate (MES) and menthol (MNT) in commercial topical gels and ointments using partial least squares (PLS) models based on FT-Raman spectra is described. The calculated relative standard errors of prediction (RSEP) were found to be in the range of 2.1–3.2% for the calibration and validation data sets. Two commercial topical gels containing 5.0% of IBU and 10% of NAP (w/w), as well as one ointment containing 15% of MES and 10% of MNT (w/w) as active pharmaceutical ingredients (APIs), were successfully quantified using the developed models with recoveries in the 99.2–101.5% range. The proposed procedure can be used as a fast, reliable and economic method for the quantification of APIs in topical gels and ointments.     

Novel calibration and color adaptation schemes in three-fringe RGB photoelasticity

Isochromatic demodulation in digital photoelasticity using RGB calibration is a two step process. The first step involves the construction of a look-up table (LUT) from a calibration experiment. In the second step, isochromatic data is demodulated by matching the colors of an analysis image with the colors existing in the LUT. As actual test and calibration experiment tint conditions vary due to different sources, color adaptation techniques for modifying an existing primary LUT are employed. However, the primary LUT is still generated from bending experiments. In this paper, RGB demodulation based on a theoretically constructed LUT has been attempted to exploit the advantages of color adaptation schemes. Thereby, the experimental mode of LUT generation and some uncertainties therein can be minimized. Additionally, a new color adaptation algorithm is proposed using quadratic Lagrangian interpolation polynomials, which is numerically better than the two-point linear interpolations available in the literature. The new calibration and color adaptation schemes are validated and applied to demodulate fringe orders in live models and stress frozen slices.     

Uncertainty quantification in LES of channel flow

In this paper, we present a Bayesian framework for estimating joint densities for large eddy simulation (LES) sub‐grid scale model parameters based on canonical forced isotropic turbulence direct numerical simulation (DNS) data. The framework accounts for noise in the independent variables, and we present alternative formulations for accounting for discrepancies between model and data. To generate probability densities for flow characteristics, posterior densities for sub‐grid scale model parameters are propagated forward through LES of channel flow and compared with DNS data. Synthesis of the calibration and prediction results demonstrates that model parameters have an explicit filter width dependence and are highly correlated. Discrepancies between DNS and calibrated LES results point to additional model form inadequacies that need to be accounted for. Copyright © 2016 John Wiley & Sons, Ltd.     

Generalized Linear Additive Smooth Structures

This article proposes a practical modeling approach that can accommodate a rich variety of predictors, united in a generalized linear model (GLM) setting. In addition to the usual ANOVA-type or covariatelinear (L) predictors, we consider modeling any combination of smooth additive (G) components, varying coefficient (V) components, and (discrete representations of) signal (S) components. We assume that G is, and the coefficients of V and S are, inherently smooth—projecting each of these onto B-spline bases using a modest number of equally spaced knots. Enough knots are used to ensure more flexibility than needed; further smoothness is achieved through a difference penalty on adjacent B-spline coefficients (P-splines). This linear re-expression allows all of the parameters associated with these components to be estimated simultaneously in one large GLM through penalized likelihood. Thus, we have the advantage of avoiding both the backfitting algorithm and complex knot selection schemes. We regulate the flexibility of each component through a separate penalty parameter that is optimally chosen based on cross-validation or an information criterion.     

2-InterConnected Facility Location: Specification,Complexity, and Exact Solutions

Connected facility location combines cost-efficient facility placement and the requirement to connect the facilities among each other. Such problems arise, e.g., in telecommunication applications where networks consist of a central core and local clients connected to it. Reliability of the core is a central issue, and we may hence require the core to be at least 2-connected.We establish the problem class of 2-interConnected Facility Location (2-iCFL), categorize its central variants, and prove that they are hard to approximate. However, our computational results show that our orientation-based ILPs allow us to effectively solve such problems to optimality for hundreds of nodes. We also establish constructive characterizations for feasible problem instances, to be used for algorithmic feasibility checks, preprocessing, and heuristics.     

PVDF压电传感器及敏感单元设计关键技术

研究了聚偏二氟乙烯(PVDF)柔性压电传感器敏感单元设计关键技术和工艺。通过传感器敏感单元设计、电极制作、极化和封装研究实现功能,结合动态冲击压缩实验,对自主研制的PVDF传感器在不同压力段进行标定和A类不确定度评价,实验数据的A类不确定度优于10%,说明所研制的PVDF压电传感器精度高、重复性好,能够满足0.3~10.0 GPa动态冲击压力测量应用需求。目前产品设计水平已达到6级,后续将进一步开展更高压段有效性的应用设计、温度补偿效应研究和工程化产品设计。     

Multivariate Calibration of Near Infrared Spectroscopy in the Presence of Light Scattering Effect: A Comparative Study

When analyzing heterogeneous samples using spectroscopy, the light scattering effect introduces non-linearity into the measurements and deteriorates the prediction accuracy of conventional linear models. This paper compares the prediction performance of two categories of chemometric methods: pre-processing techniques to remove the non-linearity and non-linear calibration techniques to directly model the non-linearity. A rigorous statistical procedure is adopted to ensure reliable comparison. The results suggest that optical path length estimation and correction (OPLEC) and Gaussian process (GP) regression are the most promising among the investigated methods. Furthermore, the combination of pre-processing and non-linear models is explored with limited success being achieved.     

Some Considerations with Regard to the Quality of Results of Analysis of Trace Element Extractable Contents in Soil and Sediment

Abstract

Attention is drawn to the necessity to demonstrate accuracy of analytical results in order to make them comparable with results obtained elsewhere in the world. Besides the general aspects of quality management (e.g. within and between laboratories), attention is paid to the pitfalls that may occur in soil and sediment extract analysis. Especially the practical aspects of calibration are being dealth with.     

Experiment of constraining symmetry energy at supra-saturation density with π~-/π~+ at HIRFL-CSR

The possibility of the experiment for constraining the symmetry energy Esym(ρ) at supra-densities via π-/π+ probe on the external target experiment of phase I ( ETE(I) ) with part coverage at forward angle at HIRFL-CSR is studied for the first time by using the isospin and momentum dependent hadronic transport model IBUU04. Based on the transport simulation with Au+Au collisions at 400 MeV/u, it is found that the differential π-/π+ ratios are more sensitive to Esym(ρ) at forward angles in laboratory reference, compared with the total yield ratio widely proposed. The insufficient coverage at lower transverse momentum maintains the sensitivity of the dependence of π-/π+ ratio on the Esym(ρ) at high density, indicating that the ETF (I) under construction in Lanzhou provides the possibility of performing the experiment for probing the asymmetric nuclear equation of state.