Uncertainty Prediction of Mining Safety Production Situation

In order to explore the occurrence and development law of mining safety production accidents, analyze its future change trends, and aim at the ambiguity, non-stationarity, and randomness of mining safety production accidents, an uncertainty prediction model for mining safety production situation is proposed. Firstly, the time series effect evaluation function is introduced to determine the optimal time granularity, which is used as the window width of fuzzy information granulation (FIG), and the time series of mining safety production situation is mapped to Low, R and Up three granular parameter sequences, according to the triangular fuzzy number; Then, the mean value of the intrinsic mode function (IMF) is maintained in the normal dynamic filtering range. After the ensemble empirical mode decomposition (EEMD), the three non-stationary granulation parameter sequences of Low, R and Up are decomposed into the intrinsic mode function components representing the detail information and the trend components representing the overall change, and then the sub-sequences are reconstructed according to the sample entropy to highlight the correlation among the sub-sequences; Finally, the cloud model language rules of mining safety production situation prediction are created. Through time series discretization, cloud transformation, concept jump, time series set division, association rule mining and uncertain reasoning, the reconstructed component sequence is modeled and predicted by uncertainty information extraction. The accuracy of the uncertainty prediction model was verified by 21 sets of test samples. The average relative errors of Low, R and Up sequences were 9.472 %, 16.671 % and 3.625 %, respectively. The research shows that the uncertainty prediction model of mining safety production situation overcomes the fuzziness, non-stationarity and uncertainty of safety production accidents, and provides theoretical reference and practical guidance for mining safety management and decision-making.

The Origin and Early Development of Chinese Warp Twisted Fabric Structure

The origin of textiles is often associated with braid. Both braids and warp twisted fabrics have twisted structures, but warp twisted fabrics are more advanced and closer to the development direction of textiles.From braids to warp twisted fabrics to various complex fabrics, it is supported by the development of social technology. We sorted and categorized related textiles unearthed in prehistoric times, combined with archaeological records and documentary records that could reflect the production situation at that time to a certain extent, and explored the connection between the origin of warp warp fabrics and the development of social technology through the combination of literature research and physical research.

DETERMINATION OF SUSTAINABLE LEVELS OF DESIGN ALTERNATIVES SELECTION IN THE WORKFLOW CAP SYSTEM

The development of the mechanical treatment workflow CAP system is aimed at the solution of a crucial task of reduction of terms and the improvement of quality of multiproduct machining manufactures work preparation, as the existing workflow CAP systems have not got the possibility of fast response to changes in a production situation often arising within the multiproduct manufacture. The authors of this paper developed the workflow CAP system, which contains the requirements of the design activity full automation, design solution multivariance, and the feedback with the engineering process implementation subsystem. The paper deals with the development of a mathematical model and the technique of searching for sustainable levels of selecting design alternatives depending on the production situation for the whole design procedures of the workflow CAP system. The authors prove the application of a mathematical tool of genetic algorithms; describe the mathematical model using its terms. As a gene, the level of selection in a separate project procedure is specified. A chromosome is a set of genes according to the project procedures. The objective function determines the minimum total time of processing of the specified nomenclature of parts based on the ranges of gene aggregates resulting from crossing and mutation operations. The result of the work is the mathematical model and the technique for identifying the sustainable levels of selection in each project procedure ensuring the possibility of self-adjustment of the workflow CAP system depending on the production situation.

O GÊNERO MEME NO ENSINO MÉDIO TÉCNICO: (RE)CONSTRUÇÕES DE SIGNIFICADOS EM PRODUÇÕES DIGITAIS DE ALUNOS

In this article, we present the analysis of the construction of speech projects marked by discursive intentions in textual productions of the digital meme genre, elaborated by students of Integrated Technical High School. The study is based on discussions about digital literacy, on Bakhtinian discussions about gender discourse and on conceptual contributions about meme. The research was configured as qualitative interpretativist, having been the data generated from a textual production workshop held with 12 IFAP students. Based on the results, it is possible to observe that the construction of the participants' speech projects is configured as productions that are established from a situated context and are loaded with evaluative appreciations in their thematic contents. The analysis also shows that the textual productions of the meme genre texts mirror meanings that go beyond both the production situation (time of the workshop) and the idea that this genre would only serve to arouse mood.

METHOD OF REDUCING ORGANIZATIONAL DOWNTIME OF EQUIPMENT WHEN CHANGING THE PRODUCT RANGE

The problem of reducing unproductive time losses in diversified industries associated with the need for equipment changeovers when changing the product range is considered. A model of a typical production situation is developed in the form of a combinatorial problem of finding a chain in a complete oriented graph. A heuristic method for solving the problem using a number of techniques that can significantly reduce the amount of search in the search for an acceptable criterion for the total duration of changeovers version of the order of processing of different types of products. Examples are given confirming the possibility of applying the method to solve this type of problems in production conditions in the operational mode.

EMD-GM-ARMA Model for Mining Safety Production Situation Prediction

In order to improve the prediction accuracy of mining safety production situation and remove the difficulty of model selection for nonstationary time series, a grey (GM) autoregressive moving average (ARMA) model based on the empirical mode decomposition (EMD) is proposed. First of all, according to the nonstationary characteristics of the mining safety accident time series, nonstationary original time series were decomposed into high- and low-frequency signals using the EMD algorithm, which represents the overall trend and random disturbances, respectively. Subsequently, the GM model was used to predict high-frequency signal sequence, while the ARMA model was used to predict low-frequency signal sequence. Finally, aiming to predict the mining safety production situation, the EMD-GM-ARMA model was constructed via superimposing the prediction results of each subsequence, thereby compared to the ARIMA model, wavelet neural network model, and PSO-SVM model. The results demonstrated that the EMD-GM-ARMA model and the PSO-SVM model hold the highest prediction accuracy in the short-term prediction, and the wavelet neural network has the lowest prediction accuracy. The PSO-SVM model’s prediction accuracy decreases in medium- and long-term predictions while the EMD-GM-ARMA model still can maintain high prediction accuracy. Moreover, the relative error fluctuations of the EMD-GM-ARMA model are relatively stable in both short-term and medium-term predictions. This shows that the EMD-GM-ARMA model can provide high-precision predictions with high stability, proving the model to be feasible and effective in predicting the mining safety production situation.