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61.
采用COMSOL软件建立了油气润滑环状流管道与ECT系统的三维物理及有限元模型,结合电磁场理论获取了传感器的电容值;建立了电容值与成像灰度值一一对应的的RBF映射模型;提出了RBF算法并应用于油气润滑两相流动的图像重建过程;以图像相对误差(IME)和图像相关系数(CORR)为评价指标对该算法的进行实验验证。研究结果表明,RBF算法在ECT系统图像成像的准确性及相关性方面可以很好的适用于油气润滑;相较于其他图像重建算法,图像精度提高了40.52%,图像分辨率提高了22.13%。 相似文献
62.
63.
Yulong Zhu Tatsuya Ishikawa Srikrishnan Siva Subramanian Bin Luo 《Soils and Foundations》2021,61(1):198-217
In 2005, the Japanese government launched a new nationwide early warning system for predicting debris flow and slope failure disasters based on rainfall intensity and the Soil Water Index (SWI). However, the Japanese government has not set early warning criteria in many mountain areas. In addition, the existing early warning criteria in some areas are much higher than realistic ones, and snowmelt water is not considered in the calculation of the SWI. These two factors have been the cause of many slope failures in seasonally cold regions, induced by rainfall and/or snowmelt, which were not predicted. Therefore, this study attempts to propose a new determination method for setting early warning criteria for rainfall- and/or snowmelt-induced slope failures in seasonally cold regions. For this purpose, the study firstly proposes a combination model for estimating snow density that incorporates the hourly snowmelt water into the Japanese early warning system more accurately by using meteorological monitoring data and modeled snow density. Next, based on case studies and parametric analyses for slope stability assessment, new early warning criteria are proposed for predicting three different patterns of slope failures under two typical types of precipitation (rainfall and snowmelt) conditions. Finally, a new determination method for setting early warning criteria in seasonally cold regions is proposed by referring to the existing early warning criteria near the target area, in accordance with the precipitation types and the local ground conditions of the slopes. Since the existing early warning criteria near the target area already take the effects of the variations in local geology and geography into account, the new determination method for early warning criteria can be applied to arbitrary areas in seasonally cold regions, without directly considering the local soil properties, in the actual design and maintenance works. 相似文献
64.
Buildings nowadays are increasingly expected to meet higher and more complex performance requirements: they should be sustainable; use zero-net energy; foster a healthy and comfortable environment for the occupants; be grid-friendly, yet economical to build and maintain. The essential ingredients for the successful development and operation of net zero- and positive-energy buildings (NZEB/PEB) are: thermal simulation models, that are accurate representations of the building and its subsystems; sensors, actuators, and user interfaces to facilitate communication between the physical and simulation layers; and finally, integrated control and optimization tools of sufficient generality that using the sensor inputs and the thermal models can take intelligent decisions, in almost real-time, regarding the operation of the building and its subsystems. To this end the aim of the present paper is to present a review on the technological developments in each of the essential ingredients that may support the future integration of successful NZEB/PEB, i.e. accurate simulation models, sensors and actuators and last but not least the building optimization and control. The integration of the user is an integral part in the dynamic behavior of the system, and this role has to be taken into account. Future prospects and research trends are discussed. 相似文献
65.
Ziad Kachachi Adnan Al-Samawi 《The International journal of environmental studies》2013,70(6):643-649
A series of experiments was carried out on different samples of tap water abstracted from the Baghdad water supply network in order to observe the effect of water on supply pipes, either scale forming or corrosive. This experimental investigation on the corrosive effect of the city of Baghdad tap water showed that the water can be classified as corrosive according to the Ryznar index, while the Langelier index showed that the water has the ability to form scale on the pipes. However, personal field observation indicated that the water is corrosive to the pipes and to the network appurtenance. Other findings are reported herein. 相似文献
66.
Blood profiles in dairy cows with displaced abomasum 总被引:1,自引:0,他引:1
An observational study was carried out in Swedish dairy herds to investigate differences between cows with and without displaced abomasum (DA), in concentrations of glucose, insulin, fructosamine, nonesterified fatty acids (NEFA), β-hydroxybutyrate, cholesterol, haptoglobin, increased enzyme activity of aspartate aminotransferase and glutamate dehydrogenase, and the revised Quantitative Insulin Sensitivity Check Index (RQUICKI). A secondary aim was to study how blood profiles for DA cows vary with time in relation to calving. Sixty-nine DA cows within 2 to 56 d postpartum, in 60 herds, were clinically examined and blood samples were drawn at the time DA was diagnosed. At the same time, 104 healthy control cows matched by herd and stage of lactation were also sampled. The blood parameters were studied using mixed linear models, including herd as a random effect, and DA (case or control), parity, breed, sampling time in relation to calving, other diseases, and the interaction between DA and time as fixed effects. Concentrations were higher in DA cows than in control cows for NEFA (least squares means 1.36 vs. 0.34 mmol/L), β-hydroxybutyrate (1.56 vs. 0.90 mmol/L), aspartate aminotransferase (1.96 vs. 0.97 μkat/L), glutamate dehydrogenase (197 vs. 78 μkat/L), and haptoglobin (0.76 vs. 0.17 g/L), whereas concentrations were lower in DA cows than in control cows for insulin (3.61 vs. 8.48 mU/L) and cholesterol (3.04 vs. 3.75 mmol/L). Glucose (2.83 vs. 2.79 mmol/L) and fructosamine (266 vs. 252 μmol/L) concentrations were similar in both groups; however, a tendency toward lower RQUICKI values (0.42 vs. 0.46) in the DA cows was found, indicating reduced insulin sensitivity. For most blood parameters, differences between DA cows and controls remained constant over time. Seventy-two percent of the DA cows had at least one other disease in the period from 1 wk antepartum to 1 wk after the DA was diagnosed. Haptoglobin could potentially be used to detect treatable infectious or inflammatory conditions in the early postpartum period, possibly reducing the incidence of DA. Consequently, there were major changes in blood profiles in cows with DA compared with healthy control cows, indicating a negative energy balance, liver cell damage, and an inflammatory response. The results contribute to an understanding of the metabolic changes in DA cows. 相似文献
67.
科技型中小企业是指以科技人员为主创办的、以创新为发展动力的、主要从事高新技术产品的研制、开发、生产和服务业务的中小规模的企业.指出了构造科技型中小企业创新能力评估指标体系的依据和原则,指标的权重确定方法采用人工神经网络技术赋予,设计了一套适合于评估科技型中小企业创新能力的指标体系,并给出了数据分析的方法和步骤,采用密切值法计算其相对排序. 相似文献
68.
Sreenivas Yelneedi S. Lakshminarayanan G.P. Rangaiah 《Journal of Process Control》2009,19(9):1458-1469
The anesthetic state is a dynamic combination of hypnosis, analgesia and neuromuscular blockade that is maintained by infusing a cocktail of drugs. This work focuses on controlling the hypnosis during a surgical procedure by automatic regulation of isoflurane and employs Bispectral Index (BIS) as the primary controlled variable. A seventh-order nonlinear pharmacokinetic–pharmacodynamic representation has been used for the hypnosis dynamics of patients. This study uses a model predictive control structure for the regulation of BIS. Performance of this controller has been tested for a range of patients and compared with two previously employed control strategies (cascade internal model controller and cascade controller with modeling error compensation). Performance of the three controllers has also been studied for a step change in BIS, measured disturbances and noise in the measured variables. Numerical simulations show that the model predictive controller performed better than the other two controllers. 相似文献
69.
70.
《国际计算机数学杂志》2012,89(1-4):31-42
OL systems and TOL systems are the simplest mathematical models for the study of the development of biological organisms with or without a variable environment, respectively. This paper contributes to the study of the properties of the languages generated by these systems and by their generalizations. Macro OL (TOL) languages are languages obtained by substituting languages of a given type in OL (TOL) languages. We study properties of certain families of macro OL (TOL) languages in particular we show that they are full AFL's. We observe that OL, TOL systems and many of their generalizations can be viewed as special classes of index grammars. 相似文献