埃塞俄比亚ADAMA风电工程风机吊装进度的主要影响因素及对策综述

总结了埃塞俄比亚ADAMA风电项目风机吊装施工进度的主要影响因素,如:风速、机位间道路、物流、货损的修复进度等,并提出了相应解决措施。在国外工程实践中,合理控制了工期,有效降低了工程成本,取得了良好效果。     

Work organisation constructs and ergonomic outcomes among European forest machine operators

The aims of the study were to: 1) create work organisation constructs for forest machine operators; 2) examine relationships between these work organisation constructs and different ergonomic outcomes. The study was carried out among forest machine operators in six European countries and was based on a questionnaire survey (n = 358). Exploratory factor analysis (EFA) was used in the formation of the construct measures of work organisation. The EFA resulted in a five-factor structure. The factors were named ‘job control’, ‘variation’, ‘job rotation’, ‘breaks’ and ‘rate of work’. Three multiple regression analyses were carried out separately for the dependent variables job satisfaction, musculoskeletal symptoms and headache/sleeping problems. All regression analyses resulted in significant overall models. The highest explained variance among the dependent variables was found for job satisfaction (R = 0.51, i.e. ‘large’ effect size). The unique contribution of the work organisation constructs varied in the models, but ‘job rotation’ contributed significantly in all regression models. The results may be used as a source for ergonomic improvements to work organisation. The present study was performed as part of the EU project ‘ErgoWood’, which resulted in a European handbook for mechanised forest operations (Gellerstedt et al. 2005 Gellerstedt S. Lidén E. Bohlin F Health and performance in mechanised forest operations The Swedish University of Agricultural Sciences, Department of Forest Products and Markets Uppsala 2005  [Google Scholar]). The results delivered part of the evidence base for a toolbox in this handbook regarding changes in work organisation to improve health and performance.     

出境台湾游客旅游目的地选择关键因素之分析

游客选择不同旅游目的地的群体行为客观存在。这种游客对目的地的选择受多种因素影响,影响程度也大小不同。文章提出出境游客目的地选择四大关键因素的假设,并以出境台湾游客为研究对象,收集、计算台湾游客在23个目的地空间分布以及交通联系指数、旅游资源丰度、对外关系度、贸易依存度的数据,采用最小二乘估计法（0LS）建立多元线性回归模型,分析空间距离、资源禀赋、对外关系、经济贸易对出境台湾游客目的地选择影响。结果显示,台湾游客的出访率与交通联系指数、贸易依存度呈正相关关系,交通、经贸直接影响出境台湾游客对目的地的选择;但与旅游资源丰度、对外关系度呈略微负相关关系,资源禀赋、对外关系并不影响出境台湾游客对目的地的选择。     

微博转发预测算法评测系统的建立及性能比较

为解决微博转发行为预测问题,提出了一个基本的预测算法评测系统框架.该系统解决了原始微博数据的抓取和预处理,以及用户微博的转发和忽略行为的判定,微博和用户的特征提取等问题,为解决微博转发行为预测问题提供了技术基础.详细分析了现有文献和工作中的微博转发行为预测算法,阐述了它们的基本原理.通过定量实验分析了不同微博转发行为预测算法的在局部预测问题和全局预测问题方面的性能,并且从算法的原理等方面出发给出了定性的分析.     

青龙瀑布景区游客满意度实证研究

随着旅游业竞争的日趋激烈,旅游景点如何在竞争中脱颖而出,对顾客满意度影响因素分析和研究至关重要。文章以万州青龙大瀑布为例,通过对影响万州青龙大瀑布顾客满意度因素的问卷调查,将影响满意度的19个变量因素运用SPSS软件进行整理分析,运用因子分析法将19个变量归为四大公共因子,分别是旅游服务、旅游保障、景区宣传、景区管理四大类,并对其进行信度检测,随后构建了顾客满意度综合评价模型,最后对如何提高顾客满意度提出对策建议,以促进旅游景点服务质量的有效提高。     

乳胶漆对比率的影响因素

讨论了影响乳胶漆对比率的各种因素。     

Obtaining mode mixity for a bimaterial interface crack using the virtual crack closure technique

We review, unify and extend work pertaining to evaluating mode mixity of interfacial fracture utilizing the virtual crack closure technique (VCCT). From the VCCT, components of the strain energy release rate (SERR) are obtained using the forces and displacements near the crack tip corresponding to the opening and sliding contributions. Unfortunately, these components depend on the crack extension size, Δ, used in the VCCT. It follows that a mode mixity based upon these components also will depend on the crack extension size. However, the components of the strain energy release rate can be used for determining the complex stress intensity factors (SIFs) and the associated mode mixity. In this study, we show that several—seemingly different—suggested methods presented in the literature used to obtain mode mixity based on the stress intensity factors are indeed identical. We also present an alternative, simpler quadratic equation to this end. Moreover, a Δ-independent strain energy release based mode mixity can be defined by introducing a “normalizing length parameter.” We show that when the reference length (used for the SIF-based mode mixity) and the normalizing length (used for Δ-independent SERR-based mode mixity) are equal, the two mode mixities are only shifted by a phase angle, depending on the bimaterial parameter ε.     

双馈发电系统中电网侧高频整流器的研制

基于三相PWM高频整流器的数学模型,详细分析了双馈发电系统中电网侧整流器的双闭环控制原理和单位功率因数的实现方法。在此基础上设计了一套整流装置,可以单位功率因数运行在整流和逆变状态下,能够实现能量的双向流动,实验结果表明该整流装置具有良好的动、静态特性。