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对六矿三水平辅助回风巷中水平误差和高程误差计算,所得的实际测量相对闭合差与《测量规程》中规定的相对闭合差进行比较,得出:贯通测量误差预计中,采用实际测量数据比用规程数据进行贯通测量误差预计更能提高测量误差预计精度。 相似文献
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本文介绍了测量不确定度和测量误差的概念，并着重介绍了测量不确定度与测量误差的区别，对计量管理和计量检定人员分析测量不确定度与测量误差具有指导意义。 相似文献
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对测量误差和测量不确定度的基本概念作了简单介绍,得出测量结果的可靠程度是通过分析和评定测量不确定度来确定的;着重介绍和探讨了测量不确定度的计算步骤和计算方法,并结合电气实验室经常遇到的电压测量给出不确定度分析和计算实例;还介绍了单次测量条件下如何利用已知条件进行不确定度的估计以及不确定度的应用范围. 相似文献
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贯通测量是矿山测量的一项重要任务,在实际工程中具有重要的作用。本文介绍了贯通测量的概念、分类和允许偏差;详细阐述了贯通测量误差预计的方法,贯通标定数据的计算及贯通开切眼、贯通点位置的确定;并以船景煤矿主平硐与排矸斜井巷道的贯通测量为例,讲述贯通测量在工程中具体运用。 相似文献
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在煤矿工程测量中,传统的经纬仪、水准仪测量,具有外业测量工作量大、内业计算复杂等特点,而全站仪的应用不但提高了测量的精度,减轻测量人员的劳动强度,而且大幅度的提高了工作效率。但伴随着全站仪的应用会产生不同于应用其它的测量仪器产生的误差,本文结合全站仪在工程测量中的应用,谈谈降低测量误差的几种方法。 相似文献
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本文简述测量误差的概念、评定方法和进行评定的意义,重点介绍了测量误差评定方法在绝缘油溶解气体组分的含量测量上的应用。并通过对不确定度评定,对测量过程中,不确定度来源进行分析,研究出一套针对测定误差的处理改进方法,以求避免误差,提高测量准确度和检测质量。 相似文献
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在外输计量过程中,造成油品计量误差的主要因素有温度、压力、密度、含水及流量计系数五方面,本文在分析各种误差产生原因进行分析,并提出了降低计量误差的措施。 相似文献
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Said Abboudi 《Journal of The Franklin Institute》2011,348(7):1192-1207
A simultaneous estimation of two convective boundary conditions problem of a two-dimensional rectangular fin is proposed by numerical approach. The aim is to estimate the evolution of the distributions of the unknown heat transfer coefficients from the transient temperature histories taken with several sensors inside a two-dimensional fin. The estimation algorithm of this inverse heat conduction problem is based on the iterative regularization method and on the conjugate gradient method. An optimal choice of the vector of the descent parameters is used in this study and shows an increase in the convergence rate. The effects of some parameters (sensor number, position, measurement errors) on the inverse solutions are discussed. 相似文献
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This paper presents an extended state observer-based output feedback adaptive controller with a continuous LuGre friction compensation for a hydraulic servo control system. A continuous approximation of the LuGre friction model is employed, which preserves the main physical characteristics of the original model without increasing the complexity of the system stability analysis. By this way, continuous friction compensation is used to eliminate the majority of nonlinear dynamics in hydraulic servo system. Besides, with the development of a new parameter adaption law, the problems of parametric uncertainties are overcome so that more accurate friction compensation is realized. For another, the developed adaption law is driven by tracking errors and observation errors simultaneously. Thus, the burden of extended state observer to solve the remaining uncertainties is alleviated greatly and high gain feedback is avoided, which means better tracking performance and robustness are achieved. The designed controller handles not only matched uncertainties but also unmatched dynamics with requiring little system information, more importantly, it is based on output feedback method, in other words, the synthesized controller only relies on input signal and position output signal of the system, which greatly reduces the effects caused by signal pollution, measurement noise and other unexpected dynamics. Lyapunov-based analysis has proved this strategy presents a prescribed tracking transient performance and final tracking accuracy while obtaining asymptotic tracking performance in the presence of parametric uncertainties only. Finally, comparative experiments are conducted on a hydraulic servo platform to verify the high tracking performance of the proposed control strategy. 相似文献
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英语学习者在学习过程中必然要犯这样或那样的错误,分析学生的错误对教学工作起着重要作用.错误分析可以使教师了解学生学习过程中所存在的问题和面临的困难,并以此调整教学内容和教学计划,指导教学工作,使所有的教学时间有效地用于提高学生的英语水平上.语言学家根据不同的理论对学习者所产生的错误有不同的分类方法。本文列举出学生普遍存在的错误典型并将之归纳为语言错误和语用错误,即是否违反了语言的结构规则:语法,词汇,(本文没有表述语音错误),还是违反了语言的使用规则:语言的使用时间,场合是否得体.通过分析错误,指出教学和学习中存在的问题。由此说明错误分析是十分必要的。 相似文献
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Lowell L. Dilworth Donovan A. McGrowder Rory K. Thompson 《Indian journal of clinical biochemistry : IJCB》2014,29(2):227-231
This study evaluated the types and frequencies of pre-examination errors recorded in the chemical pathology laboratory at the University Hospital of the West Indies, Jamaica. This was a retrospective analysis of errors recorded over a three year period. Data analysis was done on an average of 519,084 samples collected and tested per year. Samples included blood, urine, stool and other fluids. Pre-examination errors were identified and recorded following visual inspection of the samples and corresponding request forms by laboratory staff, then subsequently by the Senior Medical Technologist. Errors were generally classified as inappropriate sample (58 %), inappropriate form (23.4 %), inappropriate sample volume (9.3 %) and inappropriate sample tube (9.3 %). Over 90 % of recorded pre-examination errors were related to blood samples while urine samples accounted for 6.8 % error. Pre-examination errors were lower at this study location than elsewhere. Measures aimed at reducing instances of these errors are recommended for improved laboratory quality output. 相似文献
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泰国留学生在书面语里出现的偏误现象分为以下几个类型：复句的逻辑性偏误、程度副词偏误、遗漏偏误、增补偏误、语法规则偏误等。外国学习者所产生的偏误大体上都是基于“五个中心过程”理论而形成的。偏误的产生是正常的,偏误分析的作用就在于针对汉语自身的特点分析、归纳、总结习得者的习得规律,从而提高对外汉语的教学效果。 相似文献
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Rachna Agarwal 《Indian journal of clinical biochemistry : IJCB》2013,28(3):227-234
Laboratories have a major impact on patient safety as 80–90 % of all the diagnosis are made on the basis of laboratory tests. Laboratory errors have a reported frequency of 0.012–0.6 % of all test results. Patient safety is a managerial issue which can be enhanced by implementing active system to identify and monitor quality failures. This can be facilitated by reactive method which includes incident reporting followed by root cause analysis. This leads to identification and correction of weaknesses in policies and procedures in the system. Another way is proactive method like Failure Mode and Effect Analysis. In this focus is on entire examination process, anticipating major adverse events and pre-emptively prevent them from occurring. It is used for prospective risk analysis of high-risk processes to reduce the chance of errors in the laboratory and other patient care areas. 相似文献
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Sarit K. Das Seok Chung Ioannis Zervantonakis Joseph Atnafu Roger D. Kamm 《Biomicrofluidics》2008,2(3)
Studies on the effects of variations in temperature and mild temperature gradients on cells, gels, and scaffolds are important from the viewpoint of biological function. Small differences in temperature are known to elicit significant variations in cell behavior and individual protein reactivity. For the study of thermal effects and gradients in vitro, it is important to develop microfluidic platforms which are capable of controlling temperature gradients in an environment which mimics the range of physiological conditions. In the present paper, such a microfluidic thermal gradient system (μTGS) system is proposed which can create and maintain a thermal gradient throughout a cell-seeded gel matrix using the hot and cold water supply integrated in the system in the form of a countercurrent heat exchanger. It is found that a uniform temperature gradient can be created and maintained in the device even inside a high temperature and high humidity environment of an incubator. With the help of a hot and cold circuit controlled from outside the incubator the temperature gradient can be regulated. A numerical simulation of the device demonstrates the thermal feature of the chip. Cell viability and activity under a thermal gradient are examined by placing human breast cancer cells in the device. 相似文献
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郭腾云 《中国科学院研究生院学报》2009,26(1):65-71
以生产经济理论为基础,利用扩展的生产函数,构建了区域经济要素波动与区域经济增长的分析模型,并利用我国省市区的经济产出、投资、出口与消费需求数据及其派生数据,计算分析了1981-2003年区域经济要素投入波动与区域经济增长的数量关系。分析模型估计结果显示,区域投资、出口、消费需求等经济要素波动对中国区域经济增长产生显著影响,且这种影响是负面的,其中以出口波动的负面影响最大,消费需求波动的影响次之,投资波动影响最小。这在一定程度上说明,不仅增加区域投资、劳动力投入和出口可以促进区域经济增长,而且减少区域出口、消费需求和投资的波动也会促进区域经济增长。 相似文献