Trial application of the envelope method to the potential ambiguity problem

The optical potential ambiguity is a long-standing problem in the analysis of elastic scattering data.For a specific collid-ing system,ambiguous potential families can lead to different behaviors in the nearside and farside scattering components.By contrast,the envelope method can decompose the experimental data into two components with negative and positive deflection angles,respectively.Hence,a question arises as to whether the comparison between the calculated nearside(or farside)component and the derived positive-deflection-angle(or negative-deflection-angle)component can help analyze the potential ambiguity problem.In this study,we conducted a trial application of the envelope method to the potential ambiguity problem.The envelope method was improved by including uncertainties in the experimental data.The colliding systems of 16O+28Si at 215.2 MeV and 12C+12C at 1016 MeV were considered in the analyses.For each colliding system,the angular distribution experimental data were described nearly equally well by two potential sets,one of which is“surface transpar-ent”and the other is refractive.The calculated angular distributions were decomposed into nearside and farside scattering components.Using the improved envelope method,the experimental data were decomposed into the positive-deflection-angle and negative-deflection-angle components,which were then compared with the calculated nearside and farside components.The capability of the envelope method to analyze the potential ambiguities was also discussed.

A Semi-Analytical Method for the PDFs of A Ship Rolling in Random Oblique Waves

The PDFs(probability density functions) and probability of a ship rolling under the random parametric and forced excitations were studied by a semi-analytical method. The rolling motion equation of the ship in random oblique waves was established. The righting arm obtained by the numerical simulation was approximately fitted by an analytical function. The irregular waves were decomposed into two Gauss stationary random processes, and the CARMA(2, 1) model was used to fit the spectral density function of parametric and forced excitations. The stochastic energy envelope averaging method was used to solve the PDFs and the probability. The validity of the semi-analytical method was verified by the Monte Carlo method. The C11 ship was taken as an example, and the influences of the system parameters on the PDFs and probability were analyzed. The results show that the probability of ship rolling is affected by the characteristic wave height, wave length, and the heading angle. In order to provide proper advice for the ship’s manoeuvring, the parametric excitations should be considered appropriately when the ship navigates in the oblique seas.

Multislice behavioral modeling based on envelope domain for power amplifiers

An envelope domain multislice behavioral modeling is introduced. The tradition AM-AM and AM- PM characteristics of power amplifiers axe extended to envelope domain and base-band filter is applied to distortion complex envelope signal for description of the envelope memory effect. Using traditional one and two-tone tests, the coefficients of nonlinear model and the FIR filter can be extracted. At last the model has been applied to a 10 W WCDMA Power amplifier to predict its output signal. And simulation results show that the model output conforms very well to the traditional transistor level simulation results.

Energy-Efficiency Retrofitting Strategies for Existing Residential Building Envelope System—A Case Study in China

With the rapid development of urbanization, the Chinese government has put equal emphasis on construction and retrofitting. But those projects did not achieve optimal effect because of the lack of targeted and systematic design guidance system. In this study, it first analyzes existing retrofitting methods and sorts into five retrofitting types as a basis, and then, captures the combi-nations and permutations of retrofitting methods and materials by parts and layers to build a database. After that, it combines different kinds of ap-proaches by hierarchical matrix method to conclude the most efficient strat-egy. This study also selects typical residential buildings built between 1980 and 2000 in cold climate area of Northeast China as the research objects to test the integrity and effectiveness. As the results of this paper, it provides systematic guidance and multiple performance-based retrofitting strategies of the existing residential envelope system, which can improve indoor ther-mal comfort with low energy consumption.

Construction of Bode Envelopes Using REP Based Range Finding Algorithms

The frequency domain analysis of systems is an important topic in control theory. Powerful graphical tools exist in classic control, such as the Nyquist plot, Bode plots, and Nichols chart. These methods have been widely used to evaluate the frequency domain behavior of system. A literature survey shows that various approaches are available for the computation of the frequency response of control systems under different types of parametric dependencies, such as affine, multi-linear, polynomial, etc. However, there is a lack of tools in the literature to construct the Bode envelopes for the general nonlinear type of parametric dependencies. In this paper, we address the problem of computation of the envelope of Bode frequency response of a non-rational transfer function with nonlinear parametric uncertainties varying over a box. We propose two techniques to compute the Bode envelopes：first, based on the natural interval extensions （NIE） combined with uniform subdivision and second, based on the existing Taylor model combined with subdivision strategy. We also propose the algorithms to further speed up both methods through extrapolation techniques.

绩效目标分层管理模式在医疗设备采购过程管理中的价值研究

目的:构建绩效目标分层管理模型,探讨其在医疗设备采购过程管理中的应用价值。方法:从医疗设备采购申报层、过程层、使用层和处置层筛选采购绩效评价指标,采用熵权法和数据包络分析(DEA)法制定综合评价模型,形成人员、制度、数据和设备层面的过程管理方案。选取2019—2022年北京佑安医院采购的717台医疗设备,根据绩效目标评价方法不同分别采用传统管理模式(348台)和分层管理模式(369台)管理,对比不同管理模式下医疗设备采购的绩效目标完成度、采购过程管理质量和临床配置管理满意度。结果:采用分层管理模式的369台设备包括手术室设备、实验室设备、住院治疗设备、消毒供应设备及其他医疗设备,其采购的绩效目标完成度分别为(96.10±3.46)%、(96.76±2.65)%、(95.59±2.52)%、(96.06±2.34)%和(96.88±1.75)%,均高于传统管理模式,差异有统计学意义(t=2.663、2.801、2.858、4.111、3.548,P<0.05);采用分层管理模式的医疗设备采购申报层、过程层、使用层和处置层的综合评价DEA有效率分别为96.7%、98.6%、94.6%和99.7%,均高于传统管理模式,差异有统计学意义(χ^(2)=10.983、9.327、7.270、12.309,P<0.05);临床科室使用管理人员对采用分层管理模式的设备采购和使用平均满意度分别为(95.82±2.83)%和(97.25±1.96)%,均高于传统管理模式,差异有统计学意义(t=5.575、5.248,P<0.05)。结论:分层管理模式能够有效落实医疗设备采购绩效目标,提高医疗设备采购过程管理质量,提升采购后配置临床科室使用和管理人员满意度,保障设备运行质量。

Correlation of the slope of the initial part of P-wave envelope,hypocenter depth and plate boundary

We investigated correlation of the slope of the initial part of P-wave envelope, hypocenter depth and plate boundaries by B-Δ method, which is used to determine epicentral distances in the Japan Meteorological Agency and Japan Railway Company earthquake early warning(EEW) systems. The Tohoku region was chosen as the study region. 19,899 strong motion data for 265 events with magnitudes in the range from 5.0 to 7.6 from KiK-net(Kiban Kyoshin network) had been collected. The coefficient c to investigate is obtained from the linear relation between log B and log Δ. Compared to the hypocenter depth, the coefficients c of events is more likely to decide by the spatial correlation of the plate boundaries. The differences are likely to be due to earthquake characteristics, since deeper events in the subducting slabs the structural effects are likely to be larger than or comparable to those for shallow crust events.

基于数据包络分析法的地方财政科技支出绩效评价研究

从投入和产出两个维度,建构评估政府财政支出绩效的指标体系。以安徽省为例,利用数据包络分析法(DEA)对安徽省及其16个市的财政科技支出绩效进行全面评价。研究结果表明:“十三五”以来,近一半的年份里,全省财政科技支出的综合效率还没有达到相对有效的水平,管理和技术等因素是其主要原因;近年来16个市总体上的科技支出效率不理想,且各个地市财政科技支出规模投入具有一定的波动性,规模效率比较低的原因是16个市综合效率较低。基于此,提出推进省级科技领域财政事权和支出责任划分、实现财政科技支出向财政R&D预算管理转变、优化投入方式与结构等相关建议。

Fourier Pseudospectral Solution for a 2D Nonlinear Paraxial Envelope Equation of Laser Interactions in Plasmas

We apply a Fourier pseudospectral algorithm to solve a 2D nonlinear paraxial envelope-equation of laser interactions in plasmas. In this algorithm, we first use the second order Strang time-splitting method to split the envelope-equation into a number of equations, next we spatially discrete the filed quantity and its spatial derivatives in these equations in term of Fourier interpolation polynomials (FFT), finally we sequentially integrate the resultant equations by means of a discrete integration method in order to obtain the solution of the envelope-equation. We carry out several numerical tests to illustrate the efficiency and to determine accuracy of the algorithm. In addition, we conduct a number of numerical experiments to examine its performance. The numerical results have shown that the algorithm is highly efficient and sufficiently accurate to solve the 2D envelope-equation, furthermore, it yields an optimal performance in simulating fundamental phenomena in laser interactions in plasmas.

考虑二维等效静力风荷载的导线风偏刚性直棒法

刚性直棒法作为一种简单高效的输电导线风偏响应估算方法,在输电工程领域得到了广泛的应用,然而其适用对象仅限于水平风作用下的未覆冰导线,对于线路常遇的覆冰以及二维风荷载情况未能涉及。该文采用阵风荷载包络线法(GLE法)推导了二维等效静力风荷载的表达式,获得了考虑二维风荷载作用的导线风荷载调整系数,通过引入二维等效静力风荷载改进了现有刚性直棒法,改进后的刚性直棒法综合考虑了线路是否覆冰、二维风荷载、上升气流以及风的脉动效应。建立了某真型输电线路的精细化有限元仿真模型,采用覆冰导线气动力风洞试验结果和非线性数值仿真验证了改进后刚性直棒法的准确性。基于改进后的方法分析了竖向平均风速和导线覆冰厚度对风偏响应的影响。研究表明:考虑二维等效静力风荷载的导线风偏刚性直棒法是一种准确度明显提高的通用方法,能适用于常规的、覆冰的、有上升气流的多种工况下的导线风偏位移计算。

红外照相机的热浮法湍射流流态转捩机理探究

为了探究湍射流3种流动状态的转捩机理,设计并搭建了可控式湍射流实验仪,利用热浮法红外拍摄了3种流态,实现了湍射流的可视化及精确测量。通过实验观察和分析了包络态中流体转捩速度与雷诺数的关系,确定了转捩临界雷诺数大小范围,并推导和验证了涡环态中推进力与流体流速的半经验公式;同时通过颜色仿真展示了喷口截面处的压强分布图像;利用网格剖分的方式分析了涡环转捩机理,完善了流体运动过程的精细测量,为实验室测量雷诺数提供了一种可行方法。

Sources of China's Economic Growth:An Analysis Based on Nonparametric Accounting Method

This paper improves the slacks-based method for estimating inefficiency,derives the criteria for the selection of the weights of output and input inefficiencies in the objective function,and creates a new nonparametric method for accounting economic growth.Based on this method,the paper estimates the sources of China s economic growth from 1978 to 2013.Our findings suggest that factor input and especially capital is a major source of economic growth for China as a whole and its major regions,and that economic growth in recent years is increasingly dependent on capital.For a rather long period of time before 2005,China s northeast,central and western regions lagged behind the eastern region in terms of economic growth,and TFP and factor input are major reasons behind such regional growth disparities.Although other regions have narrowed their disparities with and even overtaken the eastern region in terms of economic growth,the key driver is the rapid increase in the contribution of factor input.Advanced technologies of eastern region should be utilized to promote TFP progress in other regions,which is vital to economic growth in these regions and China as a whole.

板壳结构在声振联合试验下的振动响应耦合分析

目的研究具有工程实践意义的板壳组合结构在声振联合作用下的响应预测方法。方法在噪声试验、振动试验和声振联合试验响应曲线的基础上,分析板壳组合结构在噪声和振动同时激励下的响应耦合规律,并根据噪声试验和振动试验的响应极值包络法,来预测在声振联合试验作用下板壳结构的响应分布。结果声振联合试验响应曲线近似于噪声试验和振动试验的最大值包络线,噪声的面激励和随机振动的基础激励在不同的频率范围内对结构响应起着主要影响。试验件的噪声试验和振动试验响应曲线在给定的频率点出现相交,小于交越频率的声振联合试验响应与振动试验高度吻合,高于交越频率的响应则以噪声试验为主。结论在工程实际中,可以直接利用振动试验和噪声试验的响应数据对声振联合试验的响应进行预测。由于交越频率难以事先获得,因此响应叠加法在实践中更易于实现。

某型舰载机目标的ISAR成像算法研究

逆合成孔径雷达(ISAR)成像技术因其能够提供目标的高分辨率二维图像,已经成为军事侦察、地球观测和灾害监测等领域的重要工具,但是,由于目标的复杂运动,传统的ISAR成像方法往往会出现图像模糊和失真的问题。距离多普勒(RD)算法通过对雷达回波数据进行二维傅里叶变换,可以有效地抑制目标的复杂运动对ISAR图像的影响,从而获得更清晰、更精确的图像,然而,在处理目标加速度和微动方面存在局限性。文中首先说明了ISAR的成像原理,介绍了运动补偿中的包络对齐,在此基础上,提出一种改进的包络对齐方法,通过某卫星成像对该算法进行验证,证明了该方法的适用性和灵活性,运用改进的包络对齐方法对某型舰载机成像,发现该方法可以有效地提高ISAR图像的质量和分辨率。

长江沿岸主要城市绿色发展效率及影响因素分析

运用熵值法、数据包络法、Malmquist指数测算了长江沿岸城市2011—2022年的绿色发展现状,并运用Tobit模型对影响该区域绿色发展效率的影响因素进行分析.结果表明,长江沿岸城市的绿色发展效率未达有效,还有很大提升空间,资源优化配置方面能力欠缺;长江沿岸城市的绿色效率从大到小排序依次是长江中游、长江下游、长江上游,技术进步是绿色发展的最大助力,技术效率是绿色发展的最大阻力;经济发展水平,利用外资和产业结构对城市的绿色发展效率起正向作用,科技水平和环保建设投入对城市绿色发展效率起负向作用.

突发公共卫生事件下各省医疗物资供给与医疗服务综合效率评价--基于DEA-RSR模型

文章对2020年新冠疫情下我国31个省份医院服务效率进行综合评价,并进行防疫前后综合效率对比,以帮助各省医疗系统提高弹性,在后疫情时代有效应对突发公共卫生事件。从提高不良输出DMU识别能力的角度,将“数据包络分析法(DEA)”和“秩和比综合比较法(RSR)”相结合,利用DEA和反向DEA模型分别从乐观和悲观的角度计算综合效率,在此基础上采用RSR法进行排序、分档。各省医院综合效率划分为四个等级,其中山东、四川、广东3个省份位于第四等级,青海和西藏位于第一等级;青海和西藏的医院在防疫期间的综合实力还有待加强,部分地区医疗资源出现挤兑,各省应调整医疗资源分配、扩大医疗服务功能。

龈沟内环形切口法用于下颌远中邻面暴露≥1/2的水平阻生第三磨牙拔除的研究

目的 探讨龈沟内环形切口法用于下颌远中邻面暴露≥1/2的水平阻生第三磨牙拔除的临床效果。方法 纳入2020年3月—2022年3月我院收治的180例需拔除下颌远中邻面暴露≥1/2的水平阻生第三磨牙的患者作为研究对象,采用随机数字表法分为观察组和对照组,每组90例。观察组采用龈沟内环形切口法,对照组采用标准封套法。比较两组术后2、7 d出血程度、疼痛程度、肿胀程度、最大开口度,术前与术后3个月下颌第二磨牙牙周探诊深度及并发症发生情况。结果 观察组术后2 d出血程度、疼痛程度、肿胀程度均轻于对照组(P<0.05),最大开口度大于对照组(P<0.05),两组术后7 d出血程度、疼痛程度、肿胀程度、最大开口度差异均无统计学意义(P>0.05);两组术后3个月下颌第二磨牙远颊位点、近颊位点、颊侧位点、远舌位点、近舌位点、舌侧位点牙周探诊深度较术前差异均无统计学意义(P>0.05),且两组组间差异无统计学意义(P>0.05);两组并发症总发生率差异无统计学意义(P>0.05)。结论 下颌远中邻面暴露≥1/2的水平阻生第三磨牙拔除术中采用龈沟内环形切口法,可减轻术后早期出血、疼痛及开口受限,缩短软组织恢复时间。

基于测井曲线包络面积预测油气藏产能

为了准确预测油气藏产能,解决复杂孔隙结构致使测井响应特征弱化,常规测井手段预测产能精度低的问题,通过采用交会图手段研究了东海盆地西湖凹陷碎屑岩储层测井曲线包络面积与产能间的关系,并优选了产能敏感性包络面积作为产能预测指标,借助波叠加性原理构建了包络面积产能预测指数,利用熵权法确定了各预测指标的权值,进而分储层类型建立了产能预测模型。结果表明:补偿中子-渗透率、电阻率-密度、电阻率-视波阻抗和视波阻抗-声波时差四组包络面积对产能的敏感性较强;本文所构建的产能预测模型精度较高,平均误差为19.4%。可见基于包络面积的产能预测模型可用于未开展动态测试的油气藏产能预测,为油气藏产能预测方法提供了新思路。

基于镜像原理的田间暗管排水流量计算方法

针对目前尚无适宜的计入复合型外包滤料影响的暗管排水流量计算方法,结合渗流力学中的镜像法和势流叠加原理,以宁夏银北灌区冬灌洗盐为背景,提出一种田面积水土壤饱和条件下考虑外包滤料影响的暗管流量公式.通过室内渗流槽试验和HYDRUS-2D软件模拟确定相关水力特征参数,将试验数据、数值模拟和努美罗夫解与文中计算公式进行了对比分析,结果表明:公式计算值与渗流槽试验数据、数值模拟值的相对误差分别在7.00%及2.05%以内;当外包滤料厚度小于15 cm时,计算值及引入有效半径概念的努美罗夫解与模拟值有较高吻合度;当外包滤料厚度大于15 cm时,计算值与数值模拟值更接近,并且优于努美罗夫解;暗管的排水流量随外包滤料渗透系数或厚度的增加而逐渐增大,但增长率逐渐变缓.基于镜像法提出的考虑复合外包滤料影响的田间暗管排水流量计算公式合理可行,拓展了暗管排水计算思路.

“双碳”背景下钢铁新产线选址的环境结合度评价——以中国宝武为例

为准确测度“双碳”(即碳达峰、碳中和的合称)背景下具体工业门类选址与环境体系的结合发展实效,通过研究钢铁新产线的选址取向及环境关切转变,提出新产线选址的环境结合度评价框架。通过数据包络分析(Data Envelopment Analysis,DEA)模型计算环境-经济效率,通过动态综合评价模型揭示时间序列上效率的变化特征,以构建一套钢铁新产线选址的环境结合度评价方法,进而对中国宝武钢铁集团部分生产基地开展实证分析。评价结果为上海宝山基地的环境结合度最高。研究表明:环境结合度是“双碳”背景下钢铁新产线向既有基地选址时主要的环境关切,而环境结合度的评价框架和评价方法可有效表征连续时间序列上既有基地与所在城市环境体系的互促共进态势,对大型钢企未来选址新产线具有一定指导作用。