铁路线路接头病害的成因分析及防治措施

本文详细介绍了铁路线路接头病害的常见种类,这些病害产生的原因和治理方法,并对这些方法在其他铁路单位采用后所取得的效果做了说明,对防治铁路线路接头病害,保障铁路运输安全,延长铁路线路设备使用寿命,具有积极的指导意义。     

大断面强流变软岩硐室加固技术相似模拟试验研究

针对鹤煤九矿井下硐室出现浆皮开裂、底臌等类似现象,采用相似模拟的方法,以鹤煤九矿31采区避难硐室临近硐室群实际地质资料为基础,研究分析了给定应力环境下不同支护方式时硐室围岩的变形破坏情况、失稳过程。作者认为,随着顶部压力的逐渐改变,顶板裂隙逐渐增加,裂隙深度和宽度逐步增加,巷道出现离层、底鼓,进而呈现大面积破坏。该结果对区段巷道布置与加固方案优化有一定的参考价值。     

矿井通风三维可视化系统及优化

系统建立了三维仿真框架,建立了三维空间属性模型和非空间属性模型,分别对空间数据和非空间数据进行储存和管理。并建立了Hardy-Cross迭代模型和离散反馈型神经网络模型优化通风网络模型。并以C#语言来实现系统的功能。     

基于VVA的多分辨率交通仿真建模过程评价框架研究

文章从多分辨率交通仿真的建模过程入手,研究了系统仿真的校核、验证与确认(Verification Validation Accreditation,VVA)过程评价的原理。在此基础上,提出了基于VVA的多分辨率交通仿真建模的过程评价框架。通过研究仿真系统生命周期中的一系列活动来评价研究结果的正确性和有效性,提高了系统的可信性,使仿真系统能够满足实际应用的需要。     

基于Flexsim的社区蔬菜直销配送流程仿真优化研究

文章以乌鲁木齐沙依巴克区社区蔬菜直销配送流程为仿真对象,运用Flexsim仿真软件对其进行模拟,对配送流程涉及到的关键设备利用率、人员空闲率等数据比较分析,提出社区蔬菜直销配送流程合理的运营模式。     

Personal Income Tax Reform in China in 2018 and Its Impact on Income Distribution

In the context of personal income tax (PIT) reform in China in 2018, this paper examines some of the major issues of concern regarding the reform and income distribution. Using the China Personal Income Tax Micro‐simulation model, the paper compares the differences between the 2011 and 2018 PIT systems, and finds that residents relying on different income sources may face a large degree of real tax rate change. Once the tax system is altered to PIT 2018, the coverage of PIT for wage earners will decrease from 46.9 to 23.4 percent, the income redistributive effect will drop from 1.95 to 1.22 percent and the PIT's role in fiscal revenue will also be negatively affected. Nevertheless, if individual income continues to grow, the share of PIT in fiscal revenue is expected to return to the 2018 level in 2022, but its income redistribution function is difficult to recover in the short term. The paper finds that the effect of PIT on income distribution depends on the tax structure. Gradual transition to an “entirely comprehensive” tax system when conditions are appropriate will achieve better income redistribution results at a lower average tax rate.     

Inter‐firm R&D collaborations and green innovation value: The role of family firms' involvement and the moderating effects of proximity dimensions

The present paper investigates the relationship between the involvement of family firms in R&D collaborations aimed at developing green solutions and the value of resulting innovations. To dig into this relationship, the moderating effects of two proximity dimensions (i.e., geographical distance and technological relatedness) are also assessed. Analyses are based on a sample of 156 joint patents classified into the “Alternative energy production” field, as defined by the International Patent Classification Green Inventory and successfully filed at the United States Patent and Trademark Office in the period 1997–2010 by publicly listed companies. According to our conjectures, results reveal a positive relationship between the involvement of family firms and green innovation value. Moreover, our findings show that this relationship is hindered when partners are geographically distant or technologically proximate. Eventually, we contribute to the literature on green innovation by unveiling under which conditions inter‐firm R&D collaborations lead to more valuable innovations.     

Application of collective knowledge diffusion in a social network environment

ABSTRACT

We present a group dynamics model that shows knowledge integration as a process occurring over time. As each individual in the group contact others, his own knowledge changes, and over time the collective knowledge is obtained. This allows modeling knowledge diffusion in a social network and while the models presented in this paper are not competitive in that area, they approach the problem from previously unconsidered direction. We test the behavior of the model in a multi-agent simulation and we test a simple advertisement campaign in a social network. We provide discussion of elements needed for making model more competitive.     

Towards multi-system sociotechnical transitions: why simulate

A number of research frameworks have been developed for studying sociotechnical transitions. These are complex phenomena, particularly those involving multi-system interactions. Given these characteristics, the paper discusses the challenges in studying transitions solely through inductive inference methods. It argues that transition research has reached a point where taking the next step should include modelling and simulation as part of the standard methodological exploratory toolkit for studying the intensity, nature and timing of system interaction that lead to transitions and for producing timely and robust policy recommendations.     

“Been-heres vs. come-heres” and other identities and ideologies along the rural–urban interface: A comparative case study in Calaveras County,California

The rural–urban interface is the place of transition between that which we call “urban” and that which we call “rural.” The interface is situated between two places perceived to be different, but which are indelibly linked. Although the functional differences between “rural” and “urban” people (or those seen as “been-heres” versus “come-heres”) seem to be diminishing, differing perspectives and preferences persist along the rural–urban edge. Such differences influence the way that land users, decision makers, and the community manage the environment and react to landscape change. Using a comparative case study in Calaveras County, California, I examine the differences and similarities between “been-heres” and “come-heres” along several lines: basic demographic characteristics, political party affiliations and ideologies, and conceptions of private property rights, concluding that the dichotomy is false but instructive. The been-here/come-here divide, rather than being a definitive means for characterizing stakeholders or predicting their behavior or perspectives, serves as a heuristic for understanding the starting places of certain actors. Furthermore, this kind of analysis reveals not only where and how people and perspectives contrast but also the ways that they converge. Improving our understandings differing people and perspectives is especially important as decision-makers struggle to plan for and manage livable places and sustainable environments among groups with varying preferences which may sometimes conflict.