基于PLC的车载平台液压自动调平系统设计

很多车载设备需要调平后才能正常工作.以PLC为控制器、液压油缸为执行元件、双轴角度传感器作为反馈元件,采用最低腿调高法的调平策略,设计了一种车载平台的液压自动调平系统.并介绍了系统的液压系统组成及原理,控制系统硬件组成及软件实现方法.该系统调平速度快,调平精度高,能实现手动/自动调平切换且操作简单,有效提高车载平台的机动性.     

间歇式自动冲洗水箱的原理和应用

现有公用卫生间的冲洗水箱种类虽多 ,但都存在共同的缺陷 ,结构复杂 ,易损坏 ,使用成本高 ,一旦损坏 ,随即影响到公用卫生间的环境卫生。为此设计出一种利用虹吸原理的间歇式自动冲洗水箱 ,不需人为控制 ,不需动力 ,能达到自动冲洗便坑的效果。整个结构中没有活动零件 ,也就没有易损件 ,最大的特点是不易损坏 ,从某种意义上讲 ,可以说永不损坏。安装方法、使用效果和其他形式一样 ,只有几个零件组成 ,结构比其他类型的自动冲洗水箱简单 ,应用虹吸原理可靠 ,可全为塑料制品 ,生产成本低于同类产品 ,宜于推广应用     

货币政策效果非对称性及"阀值效应"分析

本文基于1992年1季度至2005年2季度数据，运用LM检验和t检验，研究我国货币政策的非对称性以及“阀值效应”，得出我国货币政策的“阀值”在-0．08-0．05之间。货币政策的非对称性和“阀值”的存在是由于微观信贷市场上的信贷配给导致的。“阀值”和“阀值效应”的存在反映了信贷配给的强弱程度，“阀值”可以用作度量信贷配给程度的指标，它间接地反映了信贷市场的完善程度。     

由我国个人所得税免征额调整引发的思考

<个人所得税法>从实施以来,我国已经对免征额进行了三次调整,最近两次调整的时间间隔很近,似乎个人所得税的问题只是一个免征额的变动问题.对居民来说,个人所得税问题的实质是税负的轻重和公平问题.免征额是对个人工作和生活费用的扣除,是一个动态的概念.历次免征额的调整,只是解决个人所得税问题的权宜之计,而要真正实现个人所得税调节个人收入、实现量能负担的税收公平原则,就必须对个人所得税进行全面改革.     

θ-improved limited tolerance relation model of incomplete information system for evaluation of water conservancy project management modernization

The modernization of water conservancy project management is a complicated engineering system involving a management system, a management method, management personnel, the exertion of social, economic, and ecological effects, and so on. However, indices for evaluating the modernization of water conservancy project management are usually unobtainable in practical applications. Conducting appropriate extension of the classical rough set theory and then applying it to an incomplete information system are the key to the application of the rough set theory Based on analysis of some extended rough set models in incomplete information systems, a rough set model based on the θ-improved limited tolerance relation is put forward. At the same time, upper approximation and lower approximation are defined under this improved relation. According to the evaluation index system and management practices, the threshold for θ is defined. An example study indicates the practicability and maneuverability of the model.     

碾压混凝土坝变态混凝土自动化搅拌加浆设备的研发及应用

现有碾压混凝土坝变态混凝土采用人工挖沟槽、框量加浆的施工方式,其作业效率低、浆液浪费多且加浆均匀性差,始终是变态混凝土施工控制的薄弱环节.介绍了一种搅拌式可调控数字流量加浆的变态混凝土注浆新工艺;运用EDEM离散元软件仿真分析了变态区拌合料中搅拌加浆方式的拌合均匀性,并进行了搅拌工艺参数优化;研发出了一套变态混凝土搅拌...     

阀值效应:技术创新的低产业化分析--以中国医药技术产业化为例

技术创新遵循"阀值理论",即只有当研发资源集中到一定程度才能使研发成果成为稳定输出.我国企业规模小,销售收入少,销售收入中研发经费所占比重更低,少量的R&D经费被用在许多项目上,使得企业的新技术成果难以实现规模化的市场开发,难以实现产业化.本文的实证分析表明,R&D的投入存在着一定的"阀值效应",只有当流量、压力、能量都能够达到一定的"临界值",才能获得预期的市场效果.研发资源的极端分散化是目前我国高技术产业化发展的最大障碍,这从医药产业可以清晰地表现出来.欲使技术研发投入达到产业化要求,必须充分实现技术资源的集约化使用.     

Does computer penetration increase farmers’ income? An empirical study from China

The diffusion and adoption of modern information technology provide new chance for China to close urban-rural income gap. This paper uses China's provincial panel data from 2002 to 2013 to investigate the effect of computer penetration on rural residents' income. A public program aiming to connect every village with broadband Internet and other rural facilities provides plausibly exogenous variation in rural residents' availability and adoption of the broadband Internet, which is used to explore the instrument variable for rural computer penetration. The results show that rural computer penetration tends to increase rural residents' income over time, but the average effect remains limited. The dynamic panel threshold effects model, which allows for both the threshold variable and other covariates to be endogenous, is further used to explore the constraints of the income-increase effect of rural computer penetration. It shows that the effect is at least doubled over the average effect estimated from instrument variables method, once the digital divide causes are removed. Our findings have important implications for the government to increase rural residents' income and reduce urban-rural income gap by encouraging rural computer usage and removing the digital divide.     

Resurrecting the size effect: Evidence from a panel nonlinear cointegration model for the G7 stock markets

Firm size is known to be an important factor affecting stock returns. This study proposes a panel threshold cointegration model to investigate the impact of the size effect on stock returns for the panel of G7 countries: Canada, France, Germany, Italy, Japan, the U.K., and the U.S. over the period 1991:1–2012:12. The empirical analysis is based upon the nonlinear cointegration framework using the asymmetric ARDL cointegration methodology (Shin et al., 2011). This methodological approach permits a much richer degree of flexibility in the dynamic adjustment process toward equilibrium, than in the classical linear model. Our findings indicate the presence of asymmetric adjustment around a unique long-run equilibrium. In particular, the empirical analysis provides evidence of asymmetric effects between stock returns and the size effect, while controlling for the book-to-market ratio and the price-to-earnings ratio.     

Financial stress,sovereign debt and economic activity in industrialized countries: Evidence from dynamic threshold regressions

We analyze how the impact of a change in the sovereign debt-to-GDP ratio on economic growth depends on the level of debt, the stress level on the financial market and the membership in a monetary union. A dynamic growth model is put forward demonstrating that debt affects macroeconomic activity in a non-linear manner due to amplifications from the financial sector. Employing dynamic country-specific and dynamic panel threshold regression methods, we study the non-linear relation between the growth rate and the debt-to-GDP ratio using quarterly data for sixteen industrialized countries for the period 1981Q1-2013Q2. We find that the debt-to-GDP ratio has impaired economic growth primarily during times of high financial stress and only for countries of the European Monetary Union and not for the stand-alone countries in our sample. A high debt-to-GDP ratio by itself does not seem to necessarily negatively affect growth if financial markets are calm.