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EN
According to complex geological conditions of working face E1108 in Xin-ji mine #2, loading and running characteristic of hydraulic support, influence of depression angle on mining pressure behaviors, as well as relation between advancing speed and the support loading were measured and analyzed. The results indicate that depression angle is inversely proportional to support resistance, in other words, larger depression angle area coincides with lower support resistance area. Moreover, support resistance is generally high when working face advancing speed is slow. Technologies for controlling hydraulic support stability such as improving advancing speed properly, controlling mining height and increasing support resistance are put forward based on research.
PL
Z uwzględnieniem złożonych warunków geologicznych w ścianie E1108 w kopalni Xin-Ji #2 dokonano pomiarów i analiz obciążenia i działania podpór hydraulicznych, zbadano wpływ kąta depresji na wielkość ciśnienia poziomu wydobywczego, a także zależność pomiędzy szybkością posuwania się na przodku i obciążeniem podpór. Wyniki analiz wskazują, że kąt depresji jest odwrotnie proporcjonalny do wytrzymałości podpory. Przy większych wartościach kąta depresji mamy do czynienia z obszarem gdzie wytrzymałość podpór jest niższa. Ogólnie rzecz biorąc, wytrzymałość podpory jest zazwyczaj wysoka dla niewielkich prędkości posuwania się na przodku. W pracy przedstawiono metody kontroli stabilności podpór hydraulicznych poprzez regulację szybkości posuwania się przodka, regulację wysokości wybierania oraz poprzez zwiększenie wytrzymałości podpór.
EN
In binaural audio systems, for an optimal virtual acoustic space a set of head-related transfer functions (HRTFs) should be used that closely matches the listener’s ones. This study aims to select the most appropriate HRTF dataset from a large database for users without the need for extensive listening tests. Currently, there is no way to reliably reduce the number of datasets to a smaller, more manageable number without risking discarding potentially good matches. A neural network that estimates the appropriateness of HRTF datasets based on input vectors of anthropometric measurements is proposed. The shapes and sizes of listeners’ heads and pinnas were measured using digital photography; the measured anthropometric parameters form the feature vectors used by the neural network. A graphical user interface (GUI) was developed for participants to listen to music transformed using different HRTFs and to evaluate the fitness of each HRTF dataset. The listening scores recorded were the target outputs used to train the neural networks. The aim was to learn a mapping between anthropometric parameters and listener’s perception scores. Experimental validations were performed on 30 subjects. It is demonstrated that the proposed system produces a much more reliable HRTF selection than previously used methods.
EN
In this paper, a new method based on color features of microscopic image and least-squares support vector regression model (LS-SVR) is proposed for indirect measurement of copper concentrate grade. Red, green and blue (RGB), hue and color vector angle were extracted from color microscopic images of a copper concentrate sample and selected for the comparison. Three different estimation models based on LS-SVR were developed using RGB, hue, and color vector angle, respectively. A comparison of three models was carried out through a validation test. The best model was obtained for the hue giving a running time of 30.243 ms, root mean square error of 0.8644 and correlation coefficient value of 0.9997. The results indicated that the copper concentrate grade could be estimated by the LS-SVR model using the hue as input parameter with a satisfactory accuracy.
EN
Natural weathering processes can make coal surface more hydrophilic due to the increase of content of hydrophilic functional groups (C-O, C=O, and COOH) and the decrease of content of hydrophobic functional groups (C-C and C-H) on coal surface, and hence the flotation recovery of fine coal is reduced. In this paper, a series of flotation tests were conducted in order to investigate the changes in the flotation kinetic of bituminous coal before and after natural weathering processes. Additionally, XPS was used to indicate the changes in surface properties of bituminous coal. In the investigations the flotation kinetic was changing. The classical first-order rate constant (k) of bituminous coal flotation was reduced after the natural weathering processes. A relationship between the classical first-order rate constant (k) and the hydrophilicity ability (HA) was given.
EN
The aim of this work is to present some aggregation operators with triangular intuitionistic fuzzy numbers and study their desirable properties. Firstly, the score function and the accuracy function of triangular intuitionistic fuzzy number are given, the method for ranking triangular intuitionistic fuzzy numbers are developed. Then, some geometric aggregation operators for aggregating triangular intuitionistic fuzzy numbers are developed, such as triangular intuitionistic fuzzy weighted geometric (TIFWG) operator, the triangular intuitionistic fuzzy ordered weighted geometric (TIFOWG) operator and the triangular intuitionistic fuzzy hybrid geometric (TIFHG) operator. Moreover, an application of the new approach to multi-criteria decision making method was proposed based on the geometric average operator of TIFNs, and the new ranking method for TIFNs is used to rank the alternatives. Finally, an example analysis is given to verify and demonstrate the practicality and effectiveness of the proposed method.
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