基于导叶位置数据分析的刘家峡水电厂导叶立面间隙调整方法改进

在水电厂水轮机检修过程中,水轮机导叶立面间隙调整是一项重要而精细的工作,其主要目的是将水轮机24片矩形导叶两两相靠,调整为一个密不透水的圆筒状。传统导叶立面间隙调整方法虽然能满足调整完成后两两导叶立面间隙为零的技术要求,但因缺乏精确的反馈量和监视量,调整过程费时费力,同时可能造成导叶之间压紧程度不一的现象,对后续调整产生一定影响。通过采集机组检修前导水机构各项数据,导入三维建模软件进行精确建模,在模型中进行多项初始条件下进行水轮机导叶立面间隙模拟调整,并与检修前数据比较,得出该检修状态下导叶的标准位置。在现场实际调整过程中,根据不同水轮机导叶立面间隙分布情况、机组检修级别,结合导叶标准位置提出差异化水轮机导叶立面间隙调整策略,极大提高了水轮机导叶立面间隙[3]调整效率和精度,保证了机组运行安全性。     

Optimal control of sustainable development in the biological rehabilitation of the Azov Sea

The article is devoted to the application of the concept of sustainable development management to the task of combating the eutrophication of shallow water bodies (by the example of the Azov Sea). To describe the state dynamics of the water body, partial differential equations solved numerically by the finite difference method have been used. The dynamic problem of minimizing costs for the maintenance of the ecosystem of the water body in the defined condition, which is interpreted as the requirement for sustainable development, has been solved. The research and forecast complex, including the mathematical models of the hydrobiology of the shallow water body, environmental databases, and program library used to design scenarios of the ecological situation in the Azov Sea, has been worked out. Changes in the concentration of malicious blue-green algae due to water pollution by biogenic substances causing the rapid growth of these algae have been forecast. The influence of the spatial distribution of the temperature and the salinity on the biological treatment of the Azov Sea though the introduction of green algae, which displaced the toxic blue-green algae, has been studied. Using the designed research and forecast complex based on the materials of expeditions it is possible to investigate the key mechanisms of formation of vertical and horizontal zones in the distribution of biogenic substances, oxygen, and planktonic populations, to set the values of the parameters for management of the amount of hydrogen sulfide and hypoxemic zones, to evaluate the possibility of the biological treatment of the Azov Sea waters with the help of the introduction of the green alga Chlorella vulgaris BIN, followed by displacement of the toxic blue-algae that are most common in shallow water bodies such as Aphanizomenon flosaquae, and to rank the ecological efficiency of the factors for the management of the stability of the composition of the phytoplankton species, including the blooming of microalgae. Examples of the numerical calculations have been provided. The obtained results have been analyzed.     

Estimation of dynamics of risk factors by the dynamic regression method

A problem is considered for the estimation of dynamics of risk factors and other indicators of health by the data of a number of population studies performed in various years on the same age category of the population. In the case of the nonlinear time dependence of mean values of the quantities under study, the simple interpolation of the indices by all groups leads to incorrect estimates in view of the neglect of the cohort dynamics. A methods is described for the development and identification of the dynamic regression model of the population health, which is based on the estimation of the cohort dynamics of indices. This makes it possible to prognose the expected lavels of risk factors and to clarify causal relations. The efficiency of the model is demonstrated by an example of the processing of results of the examinations performed in the years 1982, 1987, and 1992 in North Karelia (Finland).     

大型机械部件传动空心轴用液压联轴器内外套壁厚设计的研究

船用空心轴在保证传动不发生变化情况下,可以减轻传动轴重量及传动惯性,但在装配时空心轴会出现液压联轴器内套受力变化不均,在设计液压联轴器时无法准确设计内、外套的壁厚。论文研究液压联轴器内套内压力p沿轴向的变化规律,为以后设计设计内、外套的壁厚打下理论基础。用SAS软件来分析空心轴外侧所受液压联轴器的内套的压力回归曲线并进行数据采集处理,利用高斯曲线的数学模型,算出液压联轴器内套内压力p沿轴向的变化规律方程,理论值和实测压力比较,研究了空心轴外侧压力与径向变形位移比值的变化发展趋势。理论压力值与实际压力p值基本相同,空心轴外侧压力与径向变形位移比值的变化发展趋势回归方程实际效果良好可以用来指导生产,为液压联轴器的内、外套壁厚设计提供理论支撑。     

基于机器视觉的口岸车道闸机故障远程检测方法

针对口岸车道闸机运行时间的延长，噪声信号会逐渐掩盖真实信号，从而造成信号混合行为的出现，导致口岸车道闸机抬杆机械动作故障检测精度较低的问题，提出基于机器视觉的口岸车道闸机故障远程检测方法。利用CCD传感器，最大化扫描复原口岸车道闸机抬杆机械动作故障信号，并对关键应用镜头设备进行选型处理，完成机器视觉检测的硬件结构设计。输入口岸车道闸机的远程故障图像，按照图像配准原则，得到具体的直方图修正处理结果，拼接与预处理远程故障图像。在此基础上，分析口岸车道闸机抬杆机械动作实际故障特征，通过信号参量非均匀采样的方式，对检测盲源进行分离，再联合故障信号输出信噪比数值，实现口岸车道闸机抬杆机械动作故障远程检测。实验结果表明，基于机器视觉的检测方法的口岸车道闸机抬杆机械动作故障检测准确率可达90.4%，IMF分量值较大，可有效抑制噪声信号对真实信号的覆盖影响，提高口岸车道闸机抬杆机械动作故障检测精度     

Assessment of the quality of decisions worked out by an artificial neural network (DIAG) which diagnoses a technical object

The issues of the examination and determination of the ambiguity of the identification of the states of a technical object in a diagnostic system with an artificial neural network are presented in this article. It is an important problem in the operation of each inference (decision) system, in which various types of decisions are worked out, particularly including ones for diagnostic systems. For this purpose, a diagnostic system including its elements, in which an artificial neural network is used, is characterized and described. The structure together with the algorithm of a diagnostic neural network is presented. A diagram was drawn up, and the circulation of information in the diagnostic system was described in the perspective of errors brought into decision information by the individual elements of this system. A formula for the general error during working out of decisions in the system is put forward. It was also indicated that a number of factors including interferences and influence of the environment, errors during the measurement of the values of the properties of diagnostic signals, errors at the determination of the ranges of possible (permissible and limiting) changes of the properties of diagnostic signals defined in the inference rules and the accuracy of the drawing up of diagnostic inference rules have all a direct impact on the ambiguity level of the identification of the states of a technical object. In the present article, it is also the possibilities that are put forward for the determination and optimization of the ambiguity of the identification of the states of a technical object. For this purpose, the function that determines the quality of the identification and non-identification of the object’s state was defined in this article. A practical assessment method of the ambiguity level of the identification of the states of a technical object in the examined diagnostic system is additionally presented in an example with the use of a radar system.     

Nonparametric interpolation of the Markov sequence

Consideration was given to the problem of interpolation (smoothing) of the nonobservable component of the composite Markov process within the framework of the conditional Markov scheme. In the case of the dynamic observation models such as autoregression, equations were derived for the a posteriori interpolation density of the probability of the state of the nonobservable component. The aim of the present paper was to construct a smoothing algorithm for an unknown family of the distributions of the nonobservable component of the partially observable random Markov sequence. The result was obtained for the strictly stationary random Markov processes with mixing and for the conditional densities in the observation model from the exponential family of distributions. Computer-aided modeling within the framework of the Kalman scheme demonstrated that the sampled root-mean-square error of the nonparametric smoothing algorithm constructed for an unknown state equation was situated between the errors of the optimal linear filtration and the optimal linear interpolation.     

Soil-structure interaction and effect of axial force on the dynamics of offshore structures

The offshore structures are flexible systems subjected to various types of loadings. The heavy gravitational loads on the top decks, wind and water wave pressures acting on the platforms are transferred to the soil through the piles or mat foundations. Under the vibration, the variation in the pore pressures induces additional effects on the embedded part of the piles. The effect of the soil-structure interaction on the dynamics of the structure is taken into account as the deformations of the soil caused by the motion of the structure which in turn modify the response of the structure. The effect of the axial forces, within the individual members, on the vibration of the structure is included in the formulation. The dynamic stiffness matrix of the members are developed by considering the actual mass distribution and the effect of the axial force of the members. For the members embedded into soil, the soil reactions and the skin frictions are also considered as continuously varying over the members. Therefore, the equations of motion are satisfied along any infinitesimal element of the members. The new formulation is introduced in the general purpose computer code STDYNL, then the sensitivity of the overall dynamic response of the deep water platforms to the variation of the soil characteristics and to the effect of the axial forces of the members are investigated.     

Improving the accuracy and stability of the speckle tracking technique in processing images obtained in echocardiographic examinations

Tracking techniques are widely used in the processing of images in ultrasound cardiological examinations. One of the applications of this method consists in the automatic delineation of the internal and external borders of the cardiac chambers for all frames of the source video. However, owing to significant deformations of the image, which are often observed in practice, a loss of tracking can occur. We propose a new technique to improve the accuracy and stability of the classical speckle tracking algorithm taking into account the special features of the video picture of the ultrasound examination of the heart. The method is based on an assessment of the nature of the movement of regions of the heart wall using the obtained images, prediction of the position of the speckle in the next frame, and using this information to calculate the weighted function of mutual correlation used to determine the exact position of a speckle. Testing of the proposed method on the actual clinical results of echocardiographic examinations has demonstrated its high stability and accuracy, which is sufficient for practical application in ultrasound diagnostics.     

OWA aggregation of intuitionistic fuzzy sets

We recall the concept of an intuitionistic fuzzy subset (IFS). Fundamental to an IFS is the fact that it is defined using two values, a degree of membership and degree of non-membership. The ordered weighted averaging (OWA) operator is introduced and several of its features are described. Particularly notable is the idea of the dual of an OWA operator. We next discuss the aggregation of a collection of IFS using a prescribed OWA operator. It is shown that while the aggregation of the degrees of membership is performed using the prescribed OWA operator, the aggregation of the degrees of non-membership requires use of the dual of the prescribed OWA operator. The Choquet integral aggregation operator is introduced and applied to the aggregation of IFSs. Here again the concept of the dual is needed to perform the aggregation of the degrees of non-membership. We also discuss the aggregation of IFSs using the Sugeno integral. Fundamental to this work is our realisation of the importance of the concept of the dual operators in dealing with the aggregation of IFS.