MODIFIED SCHEME BASED ON SEMI-ANALYTIC APPROACH FOR COMPUTING NON-PROBABILISTIC RELIABILITY INDEX

A new computation scheme proposed to tackle commensurate problems is devel- oped by modifying the semi-analytic approach for minimizing computational complexity. Using the proposed scheme, the limit state equations, usually referred to as the failure surface, are obtained from transformation of an interval variable to a normalized one. In order to minimize the computational cost, two algorithms for optimizing the calculation steps have been proposed. The monotonicity of the objective function can be determined from narrowing the scope of interval variables in normalized infinite space by incorporating the algorithms into the computational scheme. Two examples are used to illustrate the operation and computational efficiency of the approach. The results of these examples show that the proposed algorithms can greatly reduce the computation complexity without sacrificing the computational accuracy. The advantage of the proposed scheme can be even more efficient for analyzing sophistic structures.

The Approach of Compensation of Air Refractive Index in Thermal Expansion Coefficients Measurement Based on Laser Feedback Interferometry

We present the thermal expansion coefficient （TEC） measurement technology of compensating for the effect of variations in the refractive index based on a Nd： YA G laser feedback system, the beam frequency is shifted by a pair of aeousto-optic modulators and then the heterodyne phase measurement technique is used. The sample measured is placed in a muffle furnace with two coaxial holes opened on the opposite furnace walls. The measurement beams hit perpendicularly and coaxially on each surface of the sample. The reference beams hit on the reference mirror and the high-refiectivity mirror, respectively. By the heterodyne configuration and computing, the influences of the vibration, distortion of the sample supporter and the effect of variations in the refractive index are measured and largely minimized. For validation, the TECs of aluminum samples are determined in the temperature range of 29-748K, confirming not only the precision within 5 × 10-7 K-1 and the accuracy within 0.4% from 298K to 448K but also the high sensitivity non-contact measurement of the lower reflectivity surface induced by the sample oxidization from 448 K to 748 K.

Approach Evaluating an Investment Project under Uncertainty by Risky Index of Time

The effectiveness of evaluating an investment project based on predicting cash flows depends on the uncertainty of its future cash flows. The remoter the cash flows are, the higher the uncertainty is. Because of this, this paper suggests to discount cash flows by applying risky index of time （RIT）. Thus, the discount rate used to discount the distant cash flows is higher that the discount rate used to discount the near cash flows. By this systematic method, the risk caused by the uncertainty of future cash flows can be hedged in making investment decision. To a certain degree, this approach is reasonable in evaluating investment alternatives under uncertainty. Furthermore, the paper puts forward a practical approach on determining RIT in practice.

Evaluation of Spatial-Temporal Variability of Drought Events in Iran Using Palmer Drought Severity Index and Its Principal Factors (through 1951-2005)

Intensity and variability of droughts are considered inIranduring the period 1951 to 2005. Four variables are considered: the Palmer Drought Severity Index (PDSI), the soil moisture, the temperature and the precipitation (products used for the analysis are downloaded from the NCAR website). Link with the climatic indexLa Ninais also considered (NOAA downloadable products is used). The analysis is based on basic statistical approaches (correlation, linear regressions and Principal Component Analysis). The analysis shows that PDSI is highly correlated to the soil moisture and poorly correlated to the other variables—although the temperature in the warm season shows high correlation to the PDSI and that a severe drought was experienced during 1999-2002 inthe country.

Estimating the Variance of the Proportion of Contaminated Soil by Petroleum Spills Using Two-Dimensional Systematic Sampling under Different Approaches

In leading petroleum-producing countries like Kuwait, Brazil, Iran, Iraq and Mexico oil spills frequently occur on land, causing serious damage to crop fields. Soil remediation requires constant monitoring of the polluted area. One common monitoring method involves two-dimensional systematic sampling, which can be used to estimate the proportion of the contaminated soil and study the oil spills’ geographic distribution. A well-known issue using this sampling design involves the analytical derivation of variance of the sample mean (proportion), which requires at least two independent samples. To address the problem, this research proposed a variance estimator based on regression and a corrected estimator using the autocorrelation Geary Index under the model-assisted approach. The construction of the estimators was assisted by geo-statistical models by simulating an auxiliary variable. Similar populations to those in real oil spills were recreated, and the accuracy of proposed estimators was evaluated by comparing their performance with other well-known estimators. The factors considered in this simulation study were: a) the model for simulating the populations (exponential and wave), b) the mean and the variance of the process, c) the level of autocorrelation among units. Given the statistical and computing burdens (bias, ratio between estimated and real variance, convergence and computer time), under the exponential model, the regression estimator showed the best performance;and for the wave model, the corrected version performed even better.

Artificial Neural Network(ANN)Approach for Predicting Concrete Compressive Strength by SonReb

The compressive strength of concrete is one of most important mechanical parameters in the performance assessment of existing reinforced concrete structures.According to various international codes,core samples are drilled and tested to obtain the concrete compressive strengths.Non-destructive testing is an important alternative when destructive testing is not feasible without damaging the structure.The commonly used non-destructive testing(NDT)methods to estimate the in-situ values include the Rebound hammer test and the Ultrasonic Pulse Velocity test.The poor reliability of these tests due to different aspects could be partially contrasted by using both methods together,as proposed.in the SonReb method.There are three techniques that are commonly used to predict the compressive strength of concrete based on the SonReb measurements:computational modeling,artificial intelligence,and parametric multi-variable regression models.In a previous study the accuracy of the correlation formulas deduced from the last technique has been investigated in comparison with the effective compressive strengths based on destructive test results on core drilled in adjacent locations.The aim of this study is to verify the accuracy of Artificial Neural Approach comparing the estimated compressive strengths based on NDT measured parameters with the same effective compressive strengths.The comparisons show the best performance of ANN approach.

基于水质目标的小清河流域邹平段污染物综合治理效果评价

实施综合治理措施是改善流域水环境、提升水质的有效手段之一,进行效果评估是检验治理措施成效的关键。以小清河流域邹平段为研究对象,对3种影响该流域水质的主要污染物(NH_(3)-N、TN、TP)进行治理。根据污染物负荷的来源,从流域的点源、面源及外源提出了不同治理措施并进行5种组合。利用土壤和水评估工具(soil and water assessment tool,SWAT)模型对不同降水情况下5种情景进行模拟,分析各情景中治理措施实施后NH_(3)-N、TN、TP浓度状况,并结合R-R-V(reliability-resilience-vulnerability)指数法和熵值法对不同情景治理措施的治理效果进行综合评价。结果表明:不同措施组合的治理情景均能够改善水质状况,其中S5(城镇污水处理率提高到100%,农村污水处理率提高到80%,裸露地减少30 km^(2),上游负荷减少40%,施肥量减少40%)情景下,唐口桥断面丰水年、平水年和枯水年均达到Ⅲ类水质目标。不同降雨情况下,S5情景综合得分最高,丰水年和平水年均为0.96,枯水年为0.88,该情景的治理措施对水质改善效果最佳。因此,R-R-V指数和熵值法相结合能对综合治理措施的效果进行评价,并为小清河流域邹平段水质管理目标的实现提供治理措施筛选的依据。

经剑突下三孔胸腔镜手术对前纵隔肿瘤患者围术期指标、应激反应及并发症的影响

目的研究经剑突下三孔胸腔镜手术对前纵隔肿瘤患者围术期指标、应激反应及并发症的影响。方法选取行胸腔镜下前纵隔肿瘤切除术的患者68例,根据入路不同分为A、B 2组,各34例,A组为经侧胸入路,B组为经剑突下三孔入路。对比2组围术期指标、应激反应和术后并发症发生情况。结果在围术期指标方面,2组手术时长、手术失血量、引流天数、术后住院时长无统计学差异,而术后首次下地时间和术后止痛药使用时长则为经剑突下三孔入路组显著短于经侧胸入路组(P<0.05),且经剑突下三孔入路组术后d2、d3的VAS评分更低(P<0.05),差异有统计学意义。在疼痛相关应激反应指标方面,2组患者术后Cor、PGE2、SP血清学指标均高于正常值,但经侧胸入路组较经剑突下三孔入路组更高(P<0.05),差异有统计学意义。在并发症方面,2组患者在肺部感染、肺漏气、心律失常、肺不张、胸腔积液及皮肤感觉异常情况方面无统计学差异,而总体并发症发生率则为经剑突下三孔入路组显著低于经侧胸入路组(P<0.05)。结论经剑突下三孔胸腔镜手术治疗前纵隔肿瘤能明显减轻患者围术期的疼痛,降低术后应激反应强度,并且能有效减少肺不张、胸腔积液及皮肤感觉异常方面的并发症发生率。

以生为本的民族高校教师评价指标建构

教育评价改革作为在教育改革中具有全局性、前瞻性和艰巨性的任务,正在从各个层面破局。民族高校肩负普通高校与民族高校的“双重使命”,新时代也赋予了其“立德树人”新要求,即铸牢中华民族共同体意识,在这一主线要求下,如何优化“高校教师评价体系”,为民族地区培养大批“回得去、留得下、用得上、靠得住、干得好”的“永久牌”人才,具有重要的现实意义。本文以“以生为本”理念为指导,将铸牢中华民族共同体意识主线要求贯穿评价内容与过程,从教师和学生两个教育主体入手,反转评价视角,通过评价学生的水平、成长的速度和幅度等方面的成就评价教师的育人质量,为解决教师评价“五唯”问题提供“立”之方法。此外,在指标建构方面,结合对S大学“以生为本”的教师评价指标问卷调查结果,将评价指标建构为以生为本理念下“三用心一收获”评价体系,助力《深化新时代教育评价改革总体方案》在民族高校落地生根。

用逐步趋近法确定南阳秋季丹桂开花低温预报指标

采摘、观赏桂花需要进行开花始期预报,基于2016-2022年南阳市丹桂开花全过程多批次的开花始期记录,依次统计每年第一批次开花前,以及上一批次开花结束至下一批次开花期间的日最高气温、日平均气温和日最低气温的最小值,从中挑出各自最大值作为各气温表达形式的低温日指标,根据低温日指标统计低温过程,将间隔时间较短的不连续的低温过程合并为一个低温过程,并与连续低温过程统一为合并低温过程进行分析,统计合并低温过程开始日和期间负有效积温,分析南阳丹桂开花始期与合并低温过程开始日的关系、开花批次属性与合并低温过程期间负有效积温的关系,用相关系数和一元线性回归法对预测结果进行检验。结果表明:(1)逐步趋近法确定南阳丹桂开花前低温指标以日最高气温效果最好,优于采用日平均气温和日最低气温的结果;(2)丹桂开花前低温日指标为日最高气温<22.3℃;(3)丹桂开花前低温过程指标为,日最高气温<22.3℃自然低温过程间隔日数≤1d的合并低温过程,第1个日最高气温<22.3℃合并低温过程期间负有效积温>3.4℃·d时丹桂开花一次完成,≤3.4℃·d则丹桂开花不能一次完成,当再次出现日最高气温<22.3℃后丹桂还将开花,直至日最高气温<22.3℃合并低温过程期间负有效积温>3.4℃·d丹桂才完成本开花季最后一次开花;(4)丹桂开花始期与低温过程的关系为,日最高气温<22.3℃合并低温过程次序与丹桂开花批序一一对应,合并低温过程开始日后4~13d为丹桂开花始期,每一个日最高气温<22.3℃合并低温过程开始日(X)与丹桂开花始期(Y)的一元回归方程为Y=1.1255X+1.4683,二者呈极显著直线正相关关系。

日间经口腔前庭入路切除术对甲状腺癌患者的疗效评价

目的分析日间经口腔前庭入路甲状腺癌切除术对甲状腺癌患者的疗效。方法回顾性分析90例甲状腺癌患者的临床资料。其中实施日间经口腔前庭入路切除术的49例甲状腺癌患者作为观察组,实施常规口腔前庭入路甲状腺癌切除术的41例患者作为对照组。比较两组临床指标、血清Cor、NE、AT-Ⅱ水平及不良反应发生率。结果观察组手术预约时间[(2.26±0.58)d]、住院时间[(1.88±0.50)d]、住院费用[(21.68±0.26)万元]均显著低于对照组[(2.72±0.62)d、(2.31±0.65)d、(21.91±0.47)万元],差异有统计学意义(t=3.621,P=0.001、t=3.545,P=0.001、t=2.933,P=0.004)。术前两组Cor、NE、AT-Ⅱ血清水平比较差异不显著(P>0.05),与术前的Cor、NE、AT-Ⅱ水平相比,两组术后2 h的各指标水平均显著升高(P<0.05),与术后2 h的Cor、NE、AT-Ⅱ水平相比,两组术后7 d的各指标水平均显著降低(P<0.05),两组术后7 d的各指标水平与术前比较差异不显著(P>0.05),与对照组术前、术后2 h、术后7 d的Cor、NE、AT-Ⅱ血清水平相比,观察组各指标水平变化不显著(P>0.05)。两组不良反应总发生率比较差异不显著(χ^(2)=0.022,P=0.881)。结论日间行经口腔前庭入路甲状腺癌切除术能够缩短甲状腺癌患者的手术预约时间及住院时间,降低住院费用,且不良反应发生率较低,相对安全。

改良八字入路钢板内固定对跟骨骨折患者的影响

目的:探讨改良八字入路钢板内固定对跟骨骨折患者的影响。方法:选取2020年3月—2022年6月晋江市医院晋南分院骨科收治的62例跟骨骨折患者。随机将其分为“L”形切口组和改良八字组,各31例。“L”形切口组给予“L”形切口内固定术治疗,改良八字组给予改良八字入路钢板内固定治疗。比较两组围手术期指标,术前和术后6周影像学指标,术后6周足部功能及相关指标,并发症。结果:改良八字组手术时间和下床时间均短于“L”形切口组,术中出血量少于“L”形切口组,差异有统计学意义(P<0.05)。术后6周,两组Bohler角、Gissane角均上升,改良八字组Bohler角、Gissane角均大于“L”形切口组,差异有统计学意义(P<0.05)。改良八字组足部功能改善率高于“L”形切口组,差异有统计学意义(P<0.05)。术后6周,改良八字组骨折愈合评分高于“L”形切口组,骨折愈合时间短于“L”形切口组,差异有统计学意义(P<0.05)。两组并发症发生率比较,差异无统计学意义(P>0.05)。结论:改良八字入路钢板内固定能够降低患者术中风险,促进患者术后恢复,提高患者治疗效果,改善患者足部功能。

国家治理指数与发展中国家现代化

国家治理能力现代化是发展中国家实现现代化的重要内容,而国家治理能力的衡量和建构,有赖于科学的治理指标评价体系。本文梳理国家治理指数的历史沿革、理论概念和建构方法,探讨国家治理指数的政治经济学逻辑,研究了世界治理指数、民主多样性、法治指数等问题,分析了由西方主导的国家治理指数在评估发展中国家治理能力和绩效时可能产生的偏差,强调了国家治理指数构建应当以发展中国家为主体、以人民为中心、以实绩为基准,服务于南南合作与发展实践。

Surgical approach affecting long-term urinary continence status after robot-assisted laparoscopic prostatectomy prospectively evaluated using self-reported functional status(Expanded Prostate Cancer Index Composite,EPIC-26)

Purpose:The aim of the study was to examine the influence of the surgical approach for robot-assisted laparoscopic prostatectomy(RALP)on long-term urinary continence status in the era of self-reported functional status measures using the Expanded Prostate Cancer Index Composite 26.Materials and methods:This is a prospective evaluation of 232 patients undergoing RALP between September,2019 and September,2020.Urinary continence status and postoperative incontinence(pad usage)were evaluated 12 months after RALP using Expanded Prostate Cancer Index Composite 26 questionnaires.Patients were categorized according to their surgical approach and outcome into the following groups:successful nerve sparing(NS),primarily without nerve sparing(prim.NNS),and no nerve sparing by secondary resection(NNS by SR).The median levels of their questionnaire outcomes were evaluated and compared using the Wilcoxon rank sum test with continuity correction.Results:Urinary continence status 12 months after RALP differed significantly between the NS and prim.NNS(p=0.0071)and the NS and NNS by SR(p=0.0076)groups.There was no significant difference between the prim.NNS and NNS by SR(p=0.53)groups.Pad usage 12 months after RALP had no significant difference with regard to SR of the neurovascular bundle(p=0.14).Conclusions:Patient-reported outcomes of long-term urinary continence status seem to show no difference in postoperative continence,regardless of whether a non-nerve-sparing result was planned or reached through SR.Instead,preservation of neurovascular bundle seems to lead to better long-term continence rates.

乡村振兴中第三方的使用及其风险

现代社会不断细化的分工在根本上改变着基层治理方式,治理工作倾向于效率导向,而非效果导向。在效率导向下,基层治理中第三方被大量使用,它客观上激化并放大了基层治理中脱离群众的风险。因此,必须对责任机关第三方的使用建立必要的约束机制,要求其在一定的阐释原则、证明标准的规范下,向社会公开阐明使用第三方的合理性和必要性,确保倾斜向乡村的政策与经济真正惠及民众、振兴乡村。

基于破坏接近度的机械化施工隧道安全步距研究

为了提升机械施工效率,探究机械化施工最大安全步距,以泸石高速得妥隧道为工程背景,采用有限元差分方案,结合破坏接近度理念,研究了步距对隧道围岩与结构稳定性影响。主要结论如下:随着安全步距的增大,隧道应力释放比例增大,沉降变形增大,但是幅度逐渐减小;安全步距的增大提高了初期支护的围岩压力分担比例,造成围岩拉压应力的提升,以拉应力提升为主。安全步距增大使围岩开挖损伤区范围增大,以仰拱端头至掌子面距离90 m为界,超过90 m围岩损伤区扩展显著,建议仰拱端头至掌子面距离不超过90 m。

乳晕入路腔镜甲状腺切除术与开放性甲状腺切除术治疗甲状腺癌患者的效果比较

目的:比较乳晕入路腔镜甲状腺切除术与开放性甲状腺切除术治疗甲状腺癌患者的效果。方法:选取2021年7月至2023年1月该院收治的82例甲状腺癌患者进行前瞻性研究,按照随机数字表法将其分为观察组与对照组各41例。对照组行开放性甲状腺切除术治疗,观察组行经乳晕入路腔镜甲状腺切除术治疗。比较两组手术时间、术中出血量、住院时间、术后引流量,手术前后嗓音障碍指数(VHI)和吞咽障碍评分量表(SIS)评分,以及并发症发生率。结果:观察组手术时间、住院时间短于对照组,术中出血量、术后引流量少于对照组,差异均有统计学意义(P<0.05);术后3 d,两组VHI和SIS评分低于术前,且观察组低于对照组,差异均有统计学意义(P<0.05);两组并发症发生率比较,差异无统计学意义(P>0.05)。结论:乳晕入路腔镜甲状腺切除术治疗甲状腺癌患者可减少或降低术中出血量、术后引流量、SIS评分、VHI评分和并发症发生率,缩短手术时间和住院时间,效果优于开放性甲状腺切除术治疗。

双边型直线电机控制策略研究与仿真

针对双边型永磁式直线电机在位置控制方面存在控制精度不高,以及在转速控制方面存在响应速度慢和伺服性差等问题,提出一种基于电流、速度和位移三参数的三闭环控制策略,以提高直线电机控制系统的鲁棒性和动态性能,从而使相应的伺服系统具有良好的稳定性和可靠性。控制方案中,结合SVPWM控制中id=0的思想,电流控制器采用二阶的超螺旋滑模控制算法实现对电流环的控制;位置控制器采用基于指数趋近规律的一阶滑模控制跟踪轮廓误差来实现位置控制,并具有减弱高频抖振的功能,从而提高控制过程的动态性能。利用Matlab/Simulink软件对控制系统的控制策略在直线电机的不同工作状态以及工作突变的过程进行了仿真,结果表明,仿真波形变化趋势以及参数之间的关系与实际电机运行的物理参数一致。仿真波形的变化过程、平缓程度证明了该控制系统性能良好。

Geospatial and Statistical Analysis of Land Surface Temperature and Land Surface Characteristics of Jaipur and Ahmedabad Cities of India

Land surface temperature (LST) is a phenomenon that significantly affects the environment, the cities’ liveability, and the citizens’ well-being. This Study aims to perform a comparative study of the microclimate and Surface Urban Heat Island (SUHI) phenomenon of two metropolitan cities of India, i.e. Jaipur and Ahmedabad, using MODIS Satellite data, whereas Landsat Data was used to analyse the Land Surface Characteristics by an index-based approach. The Study’s findings reveal that Ahmedabad has 35.53 per cent of the total area classified as having a low potential, and 13.55 per cent is designated as a high potential LST zone. Meanwhile, in Jaipur, 30.45 per cent of the city’s total area is identified as a low potential LST zone and 12.69 per cent as a high potential LST zone. This Study highlights the importance of mitigating the UHI phenomenon in urban centres for the overall well-being of city dwellers. It will help policymakers and stakeholders comprehend plans and take initiatives to minimise the effects of the UHI phenomenon on rapidly growing cities. .

面向省级电网运行数据的健康指数理论研究

针对电网系统运行水平现状,提出基于省级电网运行数据的健康指数理论。基于能源保供的重要性,从运行可靠性与供电稳定性两个维度出发,提出负荷转供率、设备故障占比、重合成功率、故障恢复时间系数、故障电压等级系数五个指标。为确保指标权重计算的合理性,依次求取主观权重、客观权重,并用博弈论法求取综合权重。通过对湖南14个地市跳闸数据的分析与计算,给出不同地市的健康指数水平。最后,测算某地市全年电网健康指数水平情况,分析其健康指数变化与天气的相关性,为电网的实际运行提出建议。