文化资本积累与华村准中产阶层的形成

文化资本积累是华村准中产阶层形成的重要因素。华村第一代准中产阶层最初的发育和成长更多地是依赖外部环境与机遇,而缺乏真正意义上文化资本的投入与积累;而许多年轻一代的村民则是依赖其文化资本的积累而成为新的准中产阶层或中产阶层。     

风对导弹出水姿态影响数值分析

应用ANSYS／LS-DYNA分析技术对风对导弹出水姿态影响进行数值分析,获取了导弹在不同风浪等级条件下出水姿态变化规律。利用LS-DYNA有限元程序,为求取极限风级对导弹等运载器运动规律的求取得到了比较好的数值计算方法。     

以学生专业协会为载体, 全面提升学生技术水平探索与实践

为了提升职业院校学生技能水平,解决专业学生课后重社团、轻专业,第二课堂华而不实的问题,本文提出了一种以"学生和指导老师"为双主体的专业社团管理模式,在广东交通职业技术学院智能互联协会的实践证明,这一探索切实可行,本文详细介绍了其运行模式,并对未来进行了展望.     

航海专业预防晕船专项序列课教学探讨

根据航海专业的特点和职业的需要,探讨了航海专业开设预防晕船专项训练课的意义,提出航海专业的学生必需经常进行滚轮、浪木和旋梯等锻炼的必要性;由于此类教学存在着一定的不安全因素,所以在教学中必须通过正确引导以消除学生的恐惧心理,结合相关模仿练习,使学生对预防晕船专项训练课产生兴趣,从而达到自觉训练,提高身体机能对抗晕船的目的．     

A discrete choice framework for modeling and forecasting the adoption and diffusion of new transportation services

Major technological and infrastructural changes over the next decades, such as the introduction of autonomous vehicles, implementation of mileage-based fees, carsharing and ridesharing are expected to have a profound impact on lifestyles and travel behavior. Current travel demand models are unable to predict long-range trends in travel behavior as they do not entail a mechanism that projects membership and market share of new modes of transport (Uber, Lyft, etc.). We propose integrating discrete choice and technology adoption models to address the aforementioned issue. In order to do so, we build on the formulation of discrete mixture models and specifically Latent Class Choice Models (LCCMs), which were integrated with a network effect model. The network effect model quantifies the impact of the spatial/network effect of the new technology on the utility of adoption. We adopted a confirmatory approach to estimating our dynamic LCCM based on findings from the technology diffusion literature that focus on defining two distinct types of adopters: innovator/early adopters and imitators. LCCMs allow for heterogeneity in the utility of adoption for the various market segments i.e. innovators/early adopters, imitators and non-adopters. We make use of revealed preference (RP) time series data from a one-way carsharing system in a major city in the United States to estimate model parameters. The data entails a complete set of member enrollment for the carsharing service for a time period of 2.5 years after being launched. Consistent with the technology diffusion literature, our model identifies three latent classes whose utility of adoption have a well-defined set of preferences that are significant and behaviorally consistent. The technology adoption model predicts the probability that a certain individual will adopt the service at a certain time period, and is explained by social influences, network effect, socio-demographics and level-of-service attributes. Finally, the model was calibrated and then used to forecast adoption of the carsharing system for potential investment strategy scenarios. A couple of takeaways from the adoption forecasts were: (1) placing a new station/pod for the carsharing system outside a major technology firm induces the highest expected increase in the monthly number of adopters; and (2) no significant difference in the expected number of monthly adopters for the downtown region will exist between having a station or on-street parking.     

DOS 图l形环境下窗口类的设计

为支持〈铁路中间站场CAD系统〉用户界面的设计，我们设计了图形窗口类win-dow．本文讨论了采用面向对象的设计方法进行窗口设计的优点、窗口类的设计原则，介绍了窗口的实现和使用．     

Application of plastic framing requirements for polar ships

A new International Association of Classification Societies (ICAS) standard for Polar Ship design, in the form of a Unified Requirement is being developed by an international committee with representatives from many classification societies and with the active participation of many polar nations. The framing structural requirements have been developed by a combination of analysis of existing rules and ships, finite element analysis and analytical solutions of plastic collapse mechanisms. This paper describes the use of the rule formulae in designs. The formulae contain interactions between shear and bending and give the designer options and flexibility in satisfying the strength requirements. Effective design requires knowledge of the effects, and the possible approaches to reach a satisfactory design.     

牵引电机200级绝缘系统国产化研究进展

文章介绍了牵引电机200级绝缘系统核心绝缘材料,即有机硅无溶剂浸渍树脂的国产化研究进展,对基于国产有机硅浸渍树脂的绝缘结构与引进同类绝缘结构进行了综合对比分析.结果表明:国产绝缘结构的总体性能达到了引进结构的同等水平,可以开展进一步的工程化应用工作.     

高职课堂教改的理论误区

目前,在高职课堂教学改革中存在一些误区,这些误区涉及课堂教学的各个因素,使得课堂教学偏离了正确的方向,影响了教学效果。误区主要缘自于教改的实施者对教育基本规律的认识不足,对课堂教学中教师的定位没有正确的把握。课堂教学改革只有在实际的操作者具有丰富的专业知识和深厚的教育理论基础上才能有序开展,收到实效,否则,极有可能演变为华而不实的表演。     

大规模训练集的快速缩减

为了进一步减少支持向量机的训练时间,提出了一种基于类别质心的训练集缩减算法.该算法根据样本的几何分布去除训练集中大部分非支持向量.对样本规模在104数量级的数据集进行了训练实验,结果显示,在基本不损失分类精度的情况下,训练时间比直接用SMO(序贯最小优化)算法减少30%,说明该算法能有效地提高支持向量机的训练速度.