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1.
Based on the principle of double frequency laser interference measurement ofhigh accuracy linear grating. This technique is discussed in detail from two aspots:totol lenth cumu-lative error measurement and Morie fringe signal quality analysis of linear grating.It includes lasersignal processing tochnique, signal sampling,computer interface circuit and related algorithm. withthis methed, we can not only get its accuracy parameter of a linear grating, but aiso analyze the er-ror factors which would affect the accuracy of a linear grating in graving process. In addition,it cancny out dynamic measuremtns for other length metrological elements.  相似文献   

2.
农村人力资本现状及成因分析   总被引:2,自引:0,他引:2  
摘要:我国农村人力资本积累起点低,农业从业人员大部分是小学和初中文化程度的劳动者。后续的人力资本投资又存在着一系列的问题。农村劳动力医疗保健投资少且主要投资在疾病治疗上;农村劳动力培训投资少,人力资本积累不足,农民增收后劲乏力。造成农村人力资本现状的原因是多方面的。一方面,政府对农村人力资本投资没有足够的重视,财政投入少;农村劳动力培训本身存在着一系列的问题。另一方面,农民收入有限,特别是农民思想观念陈旧、落后,跟不上时代的发展。  相似文献   

3.
将广义时间相位解包裹方法和影栅方法相结合,设计实现了一种基于时间相位解包裹方法的三维形貌测量系统。首先采集投影物体表面上的调制影栅图案,然后使用时间相位解包裹方法获取影栅图被调制前后的解包裹相位差图,据此重建物体三维形貌。给出了相位求解的原理及实现流程,进行了实验测试。实测结果表明,系统能够高效率、高精度地重建物体表面形貌。  相似文献   

4.
5.
Lettering robot manipulator is a kind of teaching and science popularization device which is fit for schools and science museums and so on. The basic construction, parameter and control system are introduced. The homogeneous transformation equation of manipulator is created according to the Denavit-Hartenberg method, and the kinematics solution and inverse kinematics solution are analyzed. The present state of vector font handling in CAD/CAM application is summarized. Because it is difficult to analyze directly the format of TTF font file and to get the outline of a certain letter, we call the windows API function GetGlyphOutline to read the data of TTF vector font in windows system. On the dot array mongline font we have vectorize it with VC++.Through the wectorised data and kinematics equation,the track programming and control and so on can be realized.  相似文献   

6.
Melbourne's Urban Growth Boundary (UGB) was legislated in 2002 and expanded substantially in 2010. Although based on strategic planning goals, UGBs have the capacity to influence land and housing markets. Landowners on the rural–urban fringe are a stakeholder group directly impacted by UGB policy, with multiple interests in containment policies and any land‐value effects. Following the 2010 expansion, substantial windfall profits to “instant millionaire” Melbourne landowners were openly reported. This paper critically interprets claims made by landowners in 264 public submissions responding to the proposed UGB expansion, and to an accompanying new policy instrument, the Growth Areas Infrastructure Contribution (GAIC). The GAIC was, in effect, a hypothecated tax on betterment expected to result from the UGB shift. Landowners commonly expressed fears that the UGB shift would not result in claimed value increases. On this basis, the GAIC was revised such that it is—at least in intention—a system wherein the tax is to be paid by housing developers and passed forward to homebuyers. The paper argues that the series of changes to the UGB and GAIC, including the modified “purchaser pays” system, may be understood as a response to rent‐seeking policy pressures from existing landowners as “insiders.” Although the unpopularity of the GAIC with landowners might have been anticipated, the outcome appears to legitimise their misinterpretation of the premise of development gain. A broader implication is that rent‐seeking behaviour by existing property owners can determine whether and how strategic planning policies are implemented.  相似文献   

7.
基于耕地保护的城市发展空间生态适宜性评价研究   总被引:2,自引:2,他引:0  
关小克 《中国农学通报》2013,29(32):252-258
针对城市边缘地带建设用地快速增长与优质农用地大量减少的矛盾,以驻马店为例,在充分考虑农田的生态服务功能的基础上,构建了建设用地生态适宜性评价系统和耕地自然生产潜力评价系统组成的生态适宜城区扩展用地评价方法,评价了城市建设用地的生态适宜性和农地的自然宜耕性,基于保护优质耕地的目标,划分了适宜性发展空间分区,将城市发展空间划分为重点开发、优化开发、限制开发和禁止开发4个类型,结合宜居城市建设对不同分区内的耕地功能用地进行了分析,探讨了扩展用地时空配置的方法和途径。结果表明:驻马店市重点、优化、限制和禁止开发区面积分别占研究区总面积的37.05%、28.87%、17.75%、16.33%。该评价方法为城市边缘地带新增建设用地的时空配置提供了参考。  相似文献   

8.
We research fractal characteristics of ECG signal, and find that it is logarithmic linear relationship between the boxes number covering signal and box scale. It is shown that ECG signal have some characteristics. Further more, we discover that fractal dimensions at QRS site are higher than others when using a time windows to detect signal. Based on this foundation, we raise a location algorithm of QRS waves which is based on fractal boxes dimension detection methods. The application results of this algorithm show that it can get rid of noise in ECG effectively with high speed, so this algorithm can be used in real time detection of ECG signal.  相似文献   

9.
This paper discusses a calculation method which can be used to increase the measuring speed of weihging system for products. The usual measuring method can only get exact value after the value has been stable, whereas the method discussed in this paper uses a limited number of transient value obtained during measuring time to calculate the stable value. Simulation result shows that the measuring time can be reduce to about one third.  相似文献   

10.
我国冷链物流发展还比较落后且发展不平衡,现代化冷链物流体系的建成是一个长期的艰巨的任务。果蔬预冷是冷链物流的重要环节,可以显著降低流通过程中的损耗,延长运输期和货架期。相对于贮藏设备及流通设备,预冷投资小、效果显著。表明我国现阶段应以预冷为出发点,降低果蔬流通成本,推动我国现代冷链物流的发展。  相似文献   

11.
It is not able to provide the decision service information that should be instantaneous, exact and all-around for governor by means of traditional mode of information communication. And it is important problem faced by modernization office. In order to get the needed information instantaneously and satisfy requirement of coordination work, the paper presents a kind of enterprise office information platform based on dynamic coordination work. The platform can guarantee coordination work of the system dynamically and instantaneously, and it is stronger in functions, and facility in use. It is discussed in more details to the design of dynamic coordination workflow drive and coordination message service drive and so on. The application effect of practical engineering shows that the design is successful.  相似文献   

12.
贵州省LAPS系统的本地化以及简单评估   总被引:1,自引:1,他引:0  
为了在同一平台查阅不同渠道获得的气象观测资料,并生成中尺度数值模式的初始场,贵州省气象局引进LAPS(局地分析预报系统)并进行初步本地化。对2015年6月贵州省内2次大范围降水过程进行诊断分析。结果表明,融合了多种本地观测资料后,LAPS系统所输出的分析场可以较好地显示因为站点分布不均等原因而不易观测到的中尺度天气系统。但是,在反映基本反射率时,数值偏大,目前仅用于预报员参考其最大值所处的位置,暂时不能用于雷达定量降水估测(简称QPE),还需要进一步的研究和订正。  相似文献   

13.
为了探索解决传统推荐施肥技术中缺乏空间属性信息、无法处理经验性知识等问题的途径,以春玉米推荐施肥为例,通过多年多点的大田玉米缺素试验、耕层土壤网格取样的养分测试和推荐施肥知识库的构建,建立了基于GIS的推荐施肥智能决策模型。该模型可以在土壤空间信息平台上,既对施肥过程中结构化要素进行定量模拟,又对施肥过程中非结构化要素进行定性分析,这样就可以相对全面地对推荐施肥进行智能决策支持。该模型经过山西省忻州市二十里铺村春玉米大田试验进行应用,取得了良好的产量效果,具有一定的实用价值。  相似文献   

14.
在储藏过程中,粮堆可能出现发热。霉变,虫害孳生等情况。当储粮水分含量高,生虫霉变时,会引起粮堆温度升高,因此,粮堆温度是储粮状态的重要标志,必须准确地检测并适时显示,本文将计算机图形技术引入粮情检测,利用图形消隐向用户提供直观生动的三维温度分布图,用户可用鼠标选取某一点以观察,显示该点的空间位置及温度值,同时显示纵横剖面图,便于发现异常温度点,用Visual Basic6.0编制绘图程序,为研制,开发具有自主产权的储粮信息管理系统奠定了基础。  相似文献   

15.
ABSTRACT This paper is concerned with the geography of finance in the globalising knowledge‐based economy, characterised by the proliferation of information and communication technology. More specifically, the paper aims to examine the “locational structure” of financial services in such an economy and its implications for uneven regional development in Europe. In doing so, the paper engages with the concept of “space of flows” and several other theoretical approaches concerned with the geography of advanced producer services and finance. It argues that while such approaches provide a useful starting point, they need be developed further in order to inform an understanding of both the nature and the dynamics of the “locational structure” of financial services and its implications for regional economic development. This point is illustrated in the case of Ireland, focusing on “domestic” banking institutions and “international” financial services operating there. The paper concludes that while “space of flows” provides a useful metaphor for approaching the geography of financial services and other knowledge intensive business services, the conceptual and analytical emphasis should shift towards the “flows of value” that ultimately impinge upon the fortunes of cities and regions.  相似文献   

16.
卫星遥感技术在火情监测中具有监测面积大、速度快、成本低,且可长期动态监测等优势。笔者将RS和GIS技术有机结合,进行沈阳地区火情卫星遥感监测技术研究。基于火点像元背景亮温差异进行计算机自动判识,综合火点发生特点和下垫面情况进行人机交互修正火点判识阈值,利用地理信息数据进行火点精确定位,获取火点所在乡镇乃至村信息、像元个数以及土地利用情况。通过与实际火点资料对比分析,火点判识结果较理想。在2014年秋季和2015年春季火情遥感监测期间成效较好,为政府相关部门防火、救火等决策提供相应参考依据。  相似文献   

17.
In the future, vehicle will be developed intelligently, which is based on the development of information technology. Now, information fusion technique is a new direction of information management. It has the advantages of more information, arrangements and methods and has been applied to a lot of research fields, The basic principle of information fusion is discussed and its applications in domestic and international modern vehicle control system are introduced. Moreover, the authors point out the key technology of information fusion and the bright prospects of its application in automotive field are proposed  相似文献   

18.
汽车转弯自动照明控制系统数据采集滤波方法   总被引:1,自引:0,他引:1  
为了减少汽车转弯自动照明控制系统数据滤波处理中的延时,在滑动中值滤波方法基础上,提出了一种带补偿的限幅滑动中值滤波算法,通过补偿的方式跟随信号的变化趋势。该算法通过2个步骤完成滤波,先对数据进行带补偿方式的限幅处理,再进行滑动中值滤波处理。该算法综合了滑动中值滤波法的实时性以及限幅滤波法对偶然性干扰滤除的有效性,实现更准确的滤波。仿真与实测结果表明,与滑动中值滤波方法相比较,改进后的算法滤波能够实时地滤除数据中的干扰,处理时间可减少62%,滤波效果较好,且速度信号的数据滞后时间较短,实时性较高,满足系统设计要求。  相似文献   

19.
Real-time holographic three wavefront interferometer combineing wavefront interference with holography has been proposed in this paper. The apparatus can be used for a number of pratical applications including the measurement of flatness for an optical flat. Thickness for transmissive or refective films. It has peculiar character comparing with other interferometers.  相似文献   

20.
现有IEEE(institute of electrical and electronics engineers)标准,目前只能明确0.5~1.7 MHz有限频段的输电线路无源干扰谐振机理。为拓展输电线路无源干扰谐振的研究频率,引入广义谐振理论,提出了一种基于电磁场能量平衡的干扰谐振频率预测构想。将大尺度空间下输电线路铁塔阵列及天线等效为广义封闭系统,从而基于复坡印廷定理,推导了电磁开放系统广义谐振因子的表达式,求解得到的广义谐振因子零值点为无源干扰谐振频点。该方法由于避开了传统将铁塔等效为半波天线的局限,因此可以实现中波频段无源干扰谐振预测。采用IEEE标准算例进行验证,结果表明:1.7 MHz频率以下,基于广义谐振理论的无源干扰谐振频率预测值和缩比模型实测值最大误差不超过±0.169 MHz。  相似文献   

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