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1.
煤浆测灰是选煤厂在线物料分析的一个难点 ,而对浮选精煤灰分的控制更是无法涉足。文章介绍了煤浆测灰仪的基本原理和结构 ,多流测灰系统的组成和工作原理 ,煤泥浮选过程计算机控制系统的构成、工作模式及其在淮北选煤厂的使用情况。  相似文献   

2.
煤科总院唐山分院和兖州矿业 (集团 )公司兴隆庄煤矿共同研制的TW -1型智能测灰仪 ,适用于各种原煤和精煤的灰分测量 ,智能化程度高 ,测量准确可靠 ,已由专家通过了技术鉴定。此项成果针对单探测器测灰仪易受温度影响的不稳定情况 ,采用双源双探测结构 ,运用“归一化对称互补法”进行温度主动补偿 ,克服了温度的影响 ,提高了仪表的准确度与稳定性。针对工业现场环境恶劣、电磁冲击及各种干扰非常强的情况 ,主机采用了测量数据自动识别装置 ,自动剔除各种测量干扰 ,提高了设备的可靠性。由于实现了主机自动定标 ,省去了繁杂的标定步骤 ,同…  相似文献   

3.
采用新型光电式智能测沙颗分仪应用于水利工程模型试验,设计应用先进的测沙传感器、颗分传感器、高集成运算放大器、接口电路和软件研制成光电式智能测沙颗分仪。通过实际运行证明:该测沙颗分仪达到了设计指标要求,提高了模型试验测量与控制的精度和工作效率,缩短了模型试验周期,有利于水利工程研究成果质量和科研水平的提高。  相似文献   

4.
袁海峰 《自动化博览》2010,(Z1):118-120
美国优胜公司的Vector型测漏仪具有测试精度高、可重复性好等优点,本文介绍了通过德国赫优讯netTAP系列网关为该测漏仪系统提供各种现场总线及实时以太网通讯接口,从而能够连入控制系统。Vector型测漏仪目前已在通用汽车发动机装配线气密性检测中得到了良好应用,并且通讯效果稳定。  相似文献   

5.
本文简要介绍了采用物理方法的智能同位素硫份仪的开发背景和技术路线。给出了作机实验室标定的若干数据,并提出了提高仪器材度的措施。  相似文献   

6.
针对传统测硫仪存在实时性差的问题,设计一种基于ARM和μC/OS-Ⅱ的嵌入式全自动测硫仪.本文给出了系统的软硬件设计与实现,并对μC/OS-Ⅱ进行了移植.测试结果表明,任务切换时间约为510us,各任务运行无明显滞后.与传统的测硫仪相比,极大的提高了系统的实时性和稳定性.  相似文献   

7.
基于ARM和FPGA的线阵CCD测径系统的设计   总被引:1,自引:0,他引:1  
张爱雪  孟樱 《电子技术应用》2011,37(2):82-84,87
设计了一种基于ARM微处理器LPC2214与线阵CCD的在线动态测径仪,该测径仪采用FPGA实现对线阵CCD时序脉冲的驱动;以ARM微处理器为测径仪的核心,实现图像信息的处理和对整个系统的控制,保证动态、实时、准确的测量线缆直径.介绍了该仪器的基本原理,详细给出了系统硬件方案和软件流程.  相似文献   

8.
韩雪 《传感器与微系统》2015,34(1):113-115,127
介绍一种基于热导传感器的高精密测氮仪的研究与设计.对测氮仪中的核心部件热导传感器进行了理论分析与设计,并在此基础上,采用CPLD ATF1508AS的架构平台,对控制系统进行了硬件设计和软件设计,通过对热导传感器的检测和整机的实验,该测氮仪具有测量速度快、测量精度高、信噪比高等优点,准确度和精密度均远高于国家标准.  相似文献   

9.
为定量了解实际工程中测斜管扭转情况及其检验方法,以及基于测扭结果的变形测值修正方法,给出了专业的测扭仪的应用过程,分析了测斜管扭转成因以及根据实测扭转角度进行测值修正过程,以某电站工程进水口边坡上安装的CF01和CF02两根测斜管为例,采用几何修正和坐标转换的方法对测斜管导槽扭转和测值修正过程进行了深入研究,分析了现有扭转程度对测值的影响。具体工程实例证明本文方法合理可信、所选用的测扭仪可靠,对类似工程具有一定参考应用价值。  相似文献   

10.
为了防止卷取建张时对带钢造成拉窄并有效控制卷形,在热轧卷取机前增加测宽仪测量进入卷取机前的带钢宽度。基于TMEIC过程控制系统的PASolution中间件平台,开发和设计了过程控制系统与测宽仪通讯接口程序,用于设定下发带钢信息和接收测宽仪实测数据,并存储、分析数据,为提高带钢宽度控制和卷取张力控制提供数据支持。  相似文献   

11.
The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.  相似文献   

12.
We discuss the emergence of topology from a consideration of set extensions in General Systems Theory. Boundaries arise in a natural way, separating independent elements or regions of the system. Our aim is a unification of Etter theory, Kron's method of Tearing and Jessel's formulation of Huygens' Principle. This should make explicit the equivalence between the objective, structural, holographic and the subjective, relative definitions of information, sought in Bowden (1994b), reprinted in this Special Issue. It connects the abstract generalisations of Schrodinger's equation and Bom's rule derived in probabilistic Etter theory with the real world of electrical and other physical phenomena in General Physical Systems Theory. This paper can be considered as a continuation of Bowden (1990; 1994a) and as a response to Bowden (1994b), reprinted in this issue.

We review the ideas behind Kron's Method of Tearing and Jessel's Principle of Secondary sources (both special cases of the above theory) and their equivalence. We follow Hiley's argument in Hiley (1996) to show how Schrodinger's equation can be thought of as specifying the evolution of (a series of) tearings in continuous space. These can be shown on a commutative diagram as a series of similarity transforms. We compare this with Etter's derivation (Etter, 1998). We describe briefly a recently published derivation of Maxwell's equations from a non-commutative algebra and show how they fit onto a related commutative diagram. Finally we make some comments on applications of the general theory to computer systems. This paper is a series of vignettes of work in progress. It is designed to point the direction of work to come in Constructive Physics.  相似文献   

13.
磁盘缓存管理机制研究   总被引:3,自引:0,他引:3  
磁盘缓存是解决I/O性能的一种技术。文章主要讲述缓存管理组成、算法的种类及其管理策略。并对基于频率的替换算法的原理、实现方法做了详细阐述。  相似文献   

14.
Zipf's first and second laws define two striking phenomena in literary text. The two laws have applications in various fields of computer science. Recently, the study of continuous speech recognition in artificial intelligence has called for the use of statistical models of text generation. A major issue is the lack of effective and objective evaluation of the models. In this paper, four leading statistical models of text generation are evaluated with respect to Zipf's laws and we identify the Simon-Yule model as a promising approach. A significant implication of the findings for text modeling is also discussed.  相似文献   

15.
The necessity arises in a variety of tasks to classify items on the basis of the presence of one of a number of criterial sets of co-related feature values. Such sets are called class characteristics. Because such classification problems require the identification of characteristics on the basis of limited training information, they entail a difficult search problem. Consideration of the differences between the theoretical models underlying characteristic and volume pattern generators suggests a schematic approach. Schemata, sets of commonly co-occuring features values, are probabilistic indicators of class membership whenever the characteristics are unknown but the characteristic model prevails. Formal and algorithmic solutions to the classification problem when exemplars are simple (consist only of M feature or attribute values) are described. The relevance of these procedures to problems involving general (relational) data structures is also indicated.  相似文献   

16.
Abstract This paper presents some of the results of the study of seven cases of innovative pedagogical practices using ICT. The study was performed in the framework of the application of SITES M2 in Chile. The results are divided in two sections. First is a summary of each case, highlighting its innovative characteristics that serve as models of 'good practice' for Chilean teachers. Second, the results of the analysis of what teachers did are outlined; the impact on students and the type of teaching and learning activities in use. Results show that these projects did not provide evidence of having impact on students' learning as defined in the national curriculum. However, they show that students participating in these projects could learn other things, had the opportunity to develop abilities defined as cross-curricular and practised ICT related skills. The analysis of the teaching and learning activities highlights some deficiencies in the way that teachers implement new teaching strategies.  相似文献   

17.
Savanna covers about two-thirds of Africa, with forage quantity and quality being important factors determining the distribution and density of wildlife and domestic stock. Testing hypotheses about the distribution of herbivores is hampered by the absence of reliable methods for measuring the variability of vegetation quality (e.g. biochemical composition) across the landscape. It is demonstrated that hyperspectral remote sensing fills this gap by revealing simultaneously the spatial variation of foliar nitrogen (crude protein) as well as the total amount of polyphenols, in grasses and trees. For the first time, the pattern of resources important for feeding preferences in herbivores (polyphenols and nitrogen) is mapped across an extensive landscape and the modeled foliar concentrations are shown to fit with ecological knowledge of the area. We explain how estimates of nitrogen (crude protein) and polyphenols may be scaled up from point-based observations to reveal their spatial pattern, and how the variation in forage quality can influence the management of savannas, including farms, communal grazing areas, and conservation areas. It provides a glimpse of the choices herbivores must face in selecting food resources of different qualities.  相似文献   

18.
Measurements of spring phenological dates in boreal regions using NDVI can be affected by snowmelt. This impacts the analysis of interannual variations in phenology and the estimates of annual carbon fluxes. For these two objectives, snowmelt effect must be removed from the phenological detection. We propose a methodology for determining the date of onset of greening in the 1982-2004 period using SPOT-VEGETATION (VGT) and NOAA Advanced Very High Resolution Radiometer (AVHRR) data. From 1998 onwards, the date of onset of greening is taken as the date at which the Normalized Difference Water Index (NDWI), calculated from SPOT-VGT near and short-wave infrared bands, starts increasing. This index decreases with snowmelt but increases with vegetation greening. For the 1982-2001 period, the date of onset of greening is the date at which AVHRR-NDVI equals a pixel specific threshold (PST), determined using the results of the NDWI method in the years common to the two datasets. The methods are validated using in situ measurements of the dates of leaf appearance. RMSE of 6.7 and 7.8 days, respectively, is found using NDWI-VGT and PST-NOAA methodologies, and the difference between the two methodologies in the common years is small. Very importantly, the dates are not biased. The interannual variations of the 23-year spring phenology dataset on the study area in northern Eurasia are analysed. In average over the study area, an advance of 8 days and a delay of 3.6 days are, respectively, found over the periods 1982-1991 and 1993-2004. These results confirm and complete previous studies about the greening trend, remove the uncertainty due to snow, and may improve carbon budget calculations.  相似文献   

19.
The way ahead with the practical development and application of Ergonomic methods is through a better anticipation and appreciation of changes to system effectiveness and human work that will be incurred through the introduction of new technologies to the workplace. These improvements will involve an improved awareness by the system of the working context and environment. The argued future is with improvements in the handling and use of knowledge by systems. The development of suitable Ergonomics methods, or the careful adaptation of existing methods, should accompany any technological revolution. Moreover, future methods are needed that are specifically developed to be applicable to the real time study of work considering both work context and the amalgamation of results from the use of many diverse methods throughout the design and development life cycle of a system. Part of this process will be a necessary complementation of both quantitative and qualitative methods and guidelines. Another focus should be on creating improved Ergonomics participation within multidisciplinary system design and development environments throughout the system's life cycle. Only through this avenue can Ergonomics show a consistent and valued contribution to quality design and its development. In parallel to such a contribution will be an acceptance by other engineering disciplines, managers, and customers that such an application of Ergonomics is cost effective.  相似文献   

20.
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