Perturbation Analysis for the Matrix-Scaled Total Least Squares Problem

In this paper, we extend matrix scaled total least squares (MSTLS) problem with a single right-hand side to the case of multiple right-hand sides. Firstly, under some mild conditions, this paper gives an explicit expression of the minimum norm solution of MSTLS problem with multiple right-hand sides. Then, we present the Kronecker-product-based formulae for the normwise, mixed and componentwise condition numbers of the MSTLS problem. For easy estimation, we also exhibit Kronecker-product-free upper bounds for these condition numbers. All these results can reduce to those of the total least squares (TLS) problem which were given by Zheng et al. Finally, two numerical experiments are performed to illustrate our results.

Multi-scale spatial relationships between soil total nitrogen and influencing factors in a basin landscape based on multivariate empirical mode decomposition

The relationships between soil total nitrogen(STN)and influencing factors are scale-dependent.The objective of this study was to identify the multi-scale spatial relationships of STN with selected environmental factors(elevation,slope and topographic wetness index),intrinsic soil factors(soil bulk density,sand content,silt content,and clay content)and combined environmental factors(including the first two principal components(PC1 and PC2)of the Vis-NIR soil spectra)along three sampling transects located at the upstream,midstream and downstream of Taiyuan Basin on the Chinese Loess Plateau.We separated the multivariate data series of STN and influencing factors at each transect into six intrinsic mode functions(IMFs)and one residue by multivariate empirical mode decomposition(MEMD).Meanwhile,we obtained the predicted equations of STN based on MEMD by stepwise multiple linear regression(SMLR).The results indicated that the dominant scales of explained variance in STN were at scale 995 m for transect 1,at scales 956 and 8852 m for transect 2,and at scales 972,5716 and 12,317 m for transect 3.Multi-scale correlation coefficients between STN and influencing factors were less significant in transect 3 than in transects 1 and 2.The goodness of fit root mean square error(RMSE),normalized root mean square error(NRMSE),and coefficient of determination(R2)indicated that the prediction of STN at the sampling scale by summing all of the predicted IMFs and residue was more accurate than that by SMLR directly.Therefore,the multi-scale method of MEMD has a good potential in characterizing the multi-scale spatial relationships between STN and influencing factors at the basin landscape scale.

南京地区饮用水“控垢”需求分析及适用技术探讨

自来水煮沸后饮用是我国居民重要的饮水习惯,而煮沸后的“水垢”问题给供水企业和用户造成困扰。研究结合南京地区水源水质特征、现有处理工艺及“水垢”控制需求,结合“水垢”的生成反应及影响因素,探究适用于低硬度饮用水的有效“水垢”控制方法。结果表明,南京地区水源水质整体较好,且水厂均设置了深度处理工艺,可以较好地保证供水水质安全,目前比较典型的是基于“水垢”的感官水质问题。改良型诱导结晶软化工艺对煮沸后“水垢”具有较好的控制作用,软化药剂投加量宜控制在10~20 mg,投加二氧化碳回调pH,处理出水煮沸后则完全没有“水垢”,沸后水的总硬度也没有降低,且多次煮沸也没有“水垢”生成,工艺总运行费用可控制在0.06元/m^(3)左右。

数字化赋能农业绿色发展——基于共建“一带一路”国家的考察

数字化发展为各国深化智慧型农业合作、推进农业绿色可持续发展、提高国家农业全要素生产率提供了新的机遇。本文基于2010-2021年共建“一带一路”国家面板数据,运用双向固定效应模型实证检验了数字化发展对农业绿色全要素生产率的影响与作用机制。研究结果表明:共建“一带一路”国家数字化发展显著提升了其农业绿色全要素生产率。渠道检验结果表明,数字化发展主要通过扩大规模化生产及提高劳动力素质来提高农业绿色全要素生产率。异质性分析表明,与中国双边贸易密切程度高的国家,其数字化发展对农业的数字赋能效应更显著。调节效应分析表明,政府治理能力提高有助于强化数字化发展对农业绿色全要素生产率的赋能效果。

不同规模生猪养殖的成本收益及全要素生产率的动态实证分析

探究不同生猪养殖模式的盈利能力和全要素生产率,对于生猪行业高质量发展和保障猪肉有效供应具有重要意义。该文利用2009-2019年的省级面板数据,对不同养殖模式的成分收益进行分析,并利用DEA模型的Malmquist指数方法,对不同生猪养殖模式的全要素生产率进行测度及分解。结果发现:规模养殖模式具有成本比较优势,规模养殖利润高于散养,呈现周期性波动,且散养模式波动最大。不同养殖模式的全要素生产率都表现为略微提升,这主要是由于技术变化的改善,且技术效率却呈现总体下降的特征,其下降是纯技术效率和规模效率的双拖累作用所致。基于此,提出了规模化养殖、政策补贴和提高全要素生产率的建议。

碳试点政策冲击下的地区工业全要素生产率增长分析

本文基于DEA-Malmquist指数方法测算了我国各省(区、市)2003~2022年的工业全要素生产率,通过双重差分法研究发现碳交易试点政策有助于促进碳试点地区工业全要素生产率增长,并发现在2013~2022年间,碳试点地区工业全要素生产率的增长主要来源于纯技术进步和纯技术效率提升,规模效率提升的贡献相对较低。具体的,在2013~2022年间,纯技术效率、纯技术进步和规模效率所作的平均贡献分别为56.8%、36.9%和6.3%。但是从变化趋势来看,近年来碳试点地区依赖于纯技术效率提升和纯技术进步实现工业全要素生产率增长的空间在不断缩小,规模效率提升所发挥的作用在稳步增强,在2019~2022年、2020~2022年以及2021~2022年3个样本期内,规模效率提升所作的平均贡献均超过了20%,未来碳试点地区工业全要素生产率增长将愈发依托规模效率改善的增长模式。

缩短藏区大型水电站大比例尺测图时间

针对西藏高海拔施工区地质条件的特殊性,采用传统大比例尺测图难点在于地形测量时间长,投入人员、设备多,并且该水电站地势险要,岸坡陡峭,两岸只有前期勘探时的一条施工便道供测量人员使用,在开展测量时不仅会花费较长的时间在路途中,而且工作效率极低,鉴于两岸植被稀少,碎屑流密集,表层岩土呈现风化状态,松散易塌滑,测量时存在很大的安全隐患。为彻底解决使用传统测量过程中过多消耗时间的问题,发现测区现场植被较少,遮挡物较少,基本为裸露的岩体,使用无人机D2000+LiDAR专业无人机测量技术来替代传统的全站仪测图方法。

糖尿病对初次全膝关节置换围术期失血量和疼痛的影响

背景:全膝关节置换是终末期骨关节炎的主要治疗措施,但糖尿病会影响治疗效果和预后等。目的:探讨糖尿病对初次全膝关节置换围术期失血量和置换后疼痛的影响。方法:回顾性分析2021年1-4月在西安交通大学附属红会医院骨坏死与关节重建病区行初次全膝关节置换且符合纳入标准的154例患者的临床资料,根据糖尿病诊断标准分为非糖尿病组与糖尿病组,其中糖尿病组32例,男性9例,女性23例,年龄55-80(66.58±7.16)岁;非糖尿病组122例,男性34例,女性88例,年龄44-83(66.69±6.63)岁。记录两组患者围术期失血量(全失血量、隐性失血量、血红蛋白下降值和红细胞压积下降值),记录置换前和置换后的目测类比评分、HSS评分、Caprini评分等。结果与结论:①非糖尿病组的全失血量(729.93±233.83)mL显著低于糖尿病组(853.69±184.91)mL,差异有显著性意义(P<0.05),非糖尿病组的隐性失血量(624.40±233.19)mL显著低于糖尿病组(749.08±179.49)mL,差异有显著性意义(P<0.05);②置换前和置换后1个月非糖尿病组目测类比评分显著低于糖尿病组,差异有显著性意义(P<0.05),置换后3 d和置换后3个月非糖尿病组与糖尿病组的目测类比评分差异无显著性意义(P>0.05);③置换后1个月非糖尿病组HSS评分明显高于糖尿病组,差异有显著性意义(P<0.05),而置换后3个月两组HSS评分差异无显著性意义(P>0.05);④置换前和置换后3 d两组间Caprini评分差异无显著性意义(P>0.05);⑤结果表明,患糖尿病会增加初次全膝关节置换的全失血量和隐性失血量,在全膝关节置换后短期内,糖尿病会增加患者疼痛并影响关节功能恢复,但随时间延长其影响会逐渐消失。

以自我管理为导向的5A护理模式对全髋关节置换术患者自我效能评价量表评分的影响

目的:探讨以自我管理为导向的5A护理模式干预对全髋关节置换术患者自我效能评价量表(GSES)评分的影响,为临床护理提供依据。方法:选取2018年10月—2021年10月河南省直第三人民医院收治的92例全髋关节置换术患者作为研究对象,采用随机数表法将92例患者分为观察组46例和常规组46例。常规组采用常规自我管理教育模式干预,观察组在常规自我管理教育模式基础上采用以自我管理为导向的5A护理模式干预。比较两组患者自我效能[自我效能评价量表(GSES)评分]、健康状况[自测健康评定量表(SRHMS)评分]、生活质量[生活质量综合评定问卷(GQOL-74)评分]情况。结果:干预后,观察组患者GSES评分高于常规组,差异有统计学意义(t=10.314,P<0.05)。干预后,观察组患者SRHMS评分高于常规组,差异有统计学意义(t=5.098,P<0.05)。干预后,观察组患者GQOL-74评分高于常规组,差异有统计学意义(t=4.641,P<0.05)。结论:以自我管理为导向的5A护理模式干预,能够有效提升全髋关节置换术患者的GSES评分,改善健康状况,提高患者的生活质量。

Relationship of nocturnal concentrations of melatonin, gamma-aminobutyric acid and total antioxidants in peripheral blood with insomnia after stroke： study protocol for a prospective non-randomized controlled trial

Melatonin and gamma-aminobutyric acid（GABA） have been shown to regulate sleep. The nocturnal concentrations of melatonin, GABA and total antioxidants may relate to insomnia in stroke patients. In this prospective single-center non-randomized controlled clinical trial performed in the China Rehabilitation Research Center, we analyzed the relationship of nocturnal concentrations of melatonin, GABA and total antioxidants with insomnia after stroke. Patients during rehabilitation of stroke were recruited and assigned to the insomnia group or non-insomnia group. Simultaneously, persons without stroke or insomnia served as normal controls. Each group contained 25 cases. The primary outcome was nocturnal concentrations of melatonin, GABA and total antioxidants in peripheral blood. The secondary outcomes were Pittsburgh Sleep Quality Index, Insomnia Severity Index, Epworth Sleepiness Scale, Fatigue Severity Scale, Morningness-Eveningness Questionnaire（Chinese version）, and National Institute of Health Stroke Scale. The relationship of nocturnal concentrations of melatonin, GABA and total antioxidants with insomnia after stroke was analyzed and showed that they were lower in the insomnia group than in the non-insomnia group. The severity of stroke was higher in the insomnia group than in the non-insomnia group. Correlation analysis demonstrated that the nocturnal concentrations of melatonin and GABA were associated with insomnia after stroke. This trial was registered at Clinical Trials.gov, identifier： NCT03202121.

规模化奶牛场污水盐分特征分析

[目的]探讨规模化奶牛场不同处理工艺下污水的盐分特征规律,以期为粪污资源化利用提供理论依据。[方法]分别采集河北省17家奶牛场挤奶厅、尿液和固液分离后等经典型工艺处理的污水,测定Cl^(-)、SO_(4)^(2-)、Na^(+)、K^(+)、Ca^(2+)含量及全盐量和电导率,分析电导率与盐分离子间的相关性。[结果]奶牛场尿液中无机盐组分以Cl^(-)、SO_(4)^(2-)、Na^(+)、K^(+)为主,且随着处理工艺的推进,固液分离后无机盐含量逐渐降低,而挤奶厅污水中盐分含量总体上较低,仅Cl^(-)含量略高(436 mg/L);污水中各阶段的全盐量和电导率存在显著差异,且尿液的全盐量和电导率均显著高于挤奶厅和固液分离后的全盐量和电导率,分别为52.2 g/L、23.3 m S/cm;相关性分析表明,全盐量与电导率、Cl^(-)、SO_(4)^(2-)、Na^(+)、K^(+)均呈极显著正相关,相关性最弱的离子是Ca^(2+)。[结论]规模化奶牛场污水中尿液无机盐离子和全盐量最高,固液分离后的次之,挤奶厅的最低,且电导率、Cl^(-)、SO_(4)^(2-)、Na^(+)、K^(+)可表征研究污水盐度的特征因子。

老年股骨颈骨折全髋或半髋关节置换的中远期状态:倾向性评分匹配法评价

背景:关节置换是治疗老年移位性股骨颈骨折的主要手段,全髋关节置换与半髋关节置换的选择是目前具有较大争论的焦点。目的:基于倾向性评分匹配法对比直接前入路下全髋与半髋关节置换治疗老年移位性股骨颈骨折的中远期生存状态。方法:选择2016年1月至2021年1月收治的147例老年移位性股骨颈骨折患者(≥65岁),其中88例行全髋关节置换,59例行人工股骨头置换(半髋关节置换)。对于患者术前合并症采用年龄校正Charlson合并症评分表,计算患者虚弱度,并采用倾向性评分匹配法对两组患者进行1∶1匹配,比较匹配后两组患者的手术时间、出血量、术后住院时间、住院费用、营养指标、术后并发症、死亡率和术后生存时间,其中术后生存时间采用Kaplan-Meier生存分析。结果与结论:①倾向性评分匹配后,两组共有42对匹配成功,匹配后两组患者术前资料均衡可比(P>0.05);②与半髋关节置换组相比,全髋关节置换组手术时间(79.71 min vs.59.07 min,P<0.001)、出血量(839.64 mL vs.597.83 mL,P=0.001)、住院费用(56508.15元vs.41702.85元,P<0.001)明显增加,但全髋关节置换组死亡率低于半髋关节置换组(36%vs.57%,HR=0.44,95%CI:0.23-0.87,P=0.018),平均生存时间长于半髋关节置换组(59.4个月vs.43.7个月,P=0.024);③两组患者在术后住院时间、术前术后营养指标、术后整体并发症发生率上,差异均无显著性意义(P>0.05);但在术后疼痛方面,半髋关节置换组疼痛发生率明显高于全髋关节置换组(24%vs.7%,P=0.035);④整体来看,全髋关节置换具有更好的长期预后生存效果,但对于身体素质差的患者则更适合行半髋关节置换;同时,术后的疼痛可能很大程度上会对患者髋关节置换后的生活质量及存活时间产生影响。

数字乡村对农业绿色全要素生产率的影响及其作用机制

近年来,推进数字乡村建设已经成为中国的一项重要国家战略。然而,目前鲜有文献涉及数字乡村建设与农业绿色全要素生产率关系的考察。基于此,运用2019年1 740个县级行政单位样本,采用工具变量模型和中介效应模型等考察了数字乡村对农业绿色全要素生产率的影响及其作用机制,研究发现:(1)数字乡村促进了农业绿色全要素生产率的提高,并且经过工具变量检验等一系列稳健性检验后,该结论仍然成立。(2)数字乡村主要通过两个途径影响农业绿色全要素生产率,一是数字乡村通过推动农业经营主体规模经营促进农业绿色全要素生产率提高,其中对于GML和ML指数度量的农业绿色全要素生产率,规模经营度的中介效应占总效应的比例分别为1.80%和3.70%;二是数字乡村通过推动农业信息化发展促进农业绿色全要素生产率提高,其中对于GML和ML指数度量的农业绿色全要素生产率,农业信息化的中介效应占总效应的比例分别为1.70%和1.40%。(3)异质性分析发现,在农业规模经营地区数字乡村对农业绿色全要素生产率有显著的促进作用,但在非规模经营地区没有显著影响。在东部地区和中部地区数字乡村对农业绿色全要素生产率有显著促进作用,但在西部地区没有显著影响。这意味着,需要继续推进数字乡村建设与完善;重点支持农业规模经营,促进农业技术进步和农业内部产业结构优化;稳步推进农业信息化发展,助推农业生产要素和资源优化、集成配置;实施非均衡发展策略,各地因地制宜地完善数字乡村设施,充分挖掘提高农业绿色全要素生产率的潜力。

Technical Components of Total Factor Productivity Growth in Malaysian Manufacturing Industry

This article attempts to disaggregate and explore the components of TFP growth that contribute to changes in output, scale of production, and allocative efficiency and technical efficiency of the Malaysian manufacturing sector. The total factor productivity (TFP) concept defined as total output per unit of all inputs used in the production of an industry has gained a prominent place in academia. The investigation on TFP growth is obviously useful for identifying sources of output growth in the development of an industry. The TFP growth is often interchangeably understood as the technical progress or changes in technology as the sole contributor to economic development. Nonetheless there are other factors contributing to its substance. Knowledge on these technical changes would help decision makers to realize the strengths and weaknesses that contribute to the growth and development of an industry. Alternatively this research would be more beneficial in the case of cross-industry or cross-country comparative studies in order to plan for developmental goal. In such a case a model industry or country can be chosen that exhibits special growth features.

The scaling relationship of leaf area and total mass of sample plots across world trees

The scaling relationship between leaf area and total mass of plant has important implications for understanding resource allocations in the plant.The model of West,Brown and Enquist(WBE model)considers that a 3/4 scaling exponent of metabolic rate versus total mass to be optimal for each plant and has been confirmed numerous times.Although leaf area is a better proxy of the metabolic rate than leaf mass,few studies have focused on the scaling exponent of leaf area versus total mass and even fewer have discussed the diversification of this scaling exponent across different conditions.Here,I analyzed the scaling exponent of leaf area versus total mass of sample plots across world plants.I found that as the plant grows,it allocates fewer resources to photosynthetic tissues than expected by the WBE model.The results also empirically show that this scaling exponent varies significantly for different plant leaf habit,taxonomic class and geographic region.Therefore,leaf strategy in response to environmental pressure and constraint clearly plays a significant role.

Assessment of a Downloadable Application with Avatar Guidance for PT-Prescribed Home Exercise after Total Knee Arthroplasty: A 30-Day Usability and Feasibility Study

Objective: To explore the usability and feasibility of a downloadable application (APP) compared to paper handouts (CONTROL) in guiding 30 days of PT-prescribed home exercise after total knee arthroplasty (TKA), and to compare functional outcomes at 30 days postoperatively between APP and CONTROL. Design: Randomized controlled usability and feasibility study. Setting: Rehabilitation laboratories at two regional medical centers. Participants: Individuals with knee osteoarthritis undergoing unilateral TKA (APP group: N = 26;mean age, 67.0 ± 8.2 y;CONTROL group: N = 31;mean age, 64.7 ± 7.7 y). Interventions: This study assessed the user experience of a downloadable app to guide 30 days of home exercises and instruction after TKA and compared exploratory outcomes to a group using paper handouts. Main Outcome Measures: The System Usability Scale (SUS) score was used to assess patient usability experience. Raw SUS scores were dichotomized (≥72% or <72%) to determine app usability against a 75% a priori criterion for mean APP group score. Feasibility for app use was similarly evaluated in the APP group only through a priori criteria applied to computing device ownership and study use, to the absence of technology-based barriers to participation, and to completion of app-based testing. Exploratory measures compared change from baseline to 30 days for functional and patient-reported outcomes between APP and CONTROL. Results: The APP group’s mean SUS score of 79.2% at 30 days exceeded the 75% threshold for good usability. The app met the predetermined a priori feasibility criteria for absence of technology-based barriers to participation (75% of participants) and completion of app-based testing (91.3% of participants). Personal computing devices were used by 71.4% of APP participants, which was below the 75% a priori feasibility criterion. No differences between the APP and CONTROL groups were observed for functional or patient-reported outcomes. Conclusions: The app-based platform met the a priori criteria for usability for 79% of APP participants. Our findings suggest that app-based, avatar-guided home exercise after TKA has acceptable usability and feasibility. The app-guided patient assessment capability also demonstrates preliminary feasibility for guiding and administering functional and self-reported outcomes assessments.

Wavelet inverse scale space for image restoration

This paper proposes a model for image restoration by combining the wavelet shrinkage and inverse scale space （ISS） method. The ISS is applied to the wavelet representation to modify the retained wavelet coefficients, and the coefficients smaller than the threshold are set to zero. The curvature term of the ISS can remove the edge artifacts and preserve sharp edges. For the multiscale interpretation of the ISS and the multiscale property of the wavelet representation, small details are preserved. This paper illustrates that the wavelet ISS model can be deduced from the wavelet based on a total variation minimization problem. A stopping criterion is obtained from this minimization in the sense of the Bregman distance in the wavelet domain. Numerical examples show the improvement for the image denoising with the proposed method in the sense of the signal to noise ratio and with fewer details remained in the residue.

Preliminary Report on Phenom^®Femoral Component in Total Hip Replacement: The Correlation between Outcome Scores in a Cross-Seccional Study

Background: The main purpose of the present study was to assess the short term performance of a cementless femoral stem in total hip replacement. Methods: Cross-sectional observational study of a 48-patient cohort with Phenom? femoral stems implanted between June 1, 2014 and September 1, 2018, to determine clinical performance, stability, and radiographic osseointegration. Patients were followed-up from 13 to 76 months (mean: 44.5 months) and assessed using the Harris Hip Score-HHS, the Hip Disability and Osteoarthritis Outcome Score-HOOS and radiographs. Results: All stems were radiologically stable. Mean Harris Hip Score was 89.8 and the HOOS was 80.4. No statistical differences were observed among patients with different diagnoses. Conclusions: The short-term results revealed satisfactory clinical outcomes and radiological signs of implant stability in all cases. Using two functional scores was useful in detecting biases and a low to moderate agreement was found between the scores.

脑小血管病磁共振总负担对认知功能的影响

目的探索脑小血管病患者脑磁共振总负担与认知功能的相关性。方法选择2021年9月至2022年10月入住我院神经内科并经脑磁共振成像(magnetic resonance imaging,MRI)确诊的227例脑小血管病患者,收集相应的临床资料、脑影像资料、血液学指标,使用蒙特利尔认知评估量表(MoCA)评估认知状态,探索磁共振影像学标志物与认知功能障碍的相关性。结果①经多因素分析,年龄、高血压病、同型半胱氨酸、尿酸、腔隙性梗死评分和脑小血管病总负荷均与MoCA分数存在相关性,差异有统计学意义(P<0.05)。②其他变量保持不变的情况下,脑小血管病总负荷每增加1分,MoCA分数下降2.27分;腔隙评分每增加1分,MoCA分数下降0.74分;同无高血压病的患者相比,合并高血压病者MoCA分数下降0.94分;尿酸和同型半胱氨酸水平每升高1个单位,MoCA分数分别下降0.01分和0.07分;年龄每长1岁,MoCA分数下降0.07分。总体来看,所有的预测变量解释了MoCA分数下降55.1%的变化。结论脑小血管病患者的认知功能受多种因素影响,脑MRI表现在一定程度上代表了脑小血管病脑内的病理状态,提示脑MRI总负担对认知功能下降有预警意义。

乡村振兴战略下农地规模经营对农业绿色发展的影响

农地规模经营对乡村振兴战略下农业绿色发展有重要意义。本文基于2000—2020年我国30个省(区、市)面板数据,以农业绿色全要素生产率(简称农业绿色TFP)指标表征农业绿色发展,运用SSBM-GML生产率指数模型对其进行测算,采用面板固定效应和门槛效应模型探究农地规模经营对农业绿色发展的影响。结果表明:研究期内全国农业绿色TFP时序上呈波动平缓上升趋势、空间上存在省际差异性特征;在全国层面,直接效应模型下农地规模经营对农业绿色TFP产生“先促进后抑制”的非线性效应,门槛效应模型下农地规模经营对农业绿色TFP产生边际递减的正向效应;在区域层面,农地规模经营对农业绿色TFP存在异质性影响,东部地区与全国样本回归特征一致,中部和西部地区农地规模经营与农业绿色TFP的关系不显著。规模化在提升农业生产效率的同时,对农业绿色发展的影响是双向的,研究建议根据经济发展水平、农业生产条件等采取符合自身的规模化经营方式以促进农业绿色发展。