cloud theory
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2021 ◽  
Author(s):  
Wenjing Qu

Most of metabolic processes are extremely complicated but occur spontaneously and steadily, the essential reason of which may be either a thermodynamic problem or related to some quantum properties. Here, collapse selection is interpreted with an analytical model of energy transfer, from which the concept of quantum cloud is defined as that during undetectable changes of a group of particles between its effective changes, particles are in the superposition of various energy states and the group is named as a cloud. It is deduced from a conservation notion of matter proportions that active cloud collapses have least-time expectation while passive collapses have matter-proportion expectation. As the results, quantum Zeno effect is a typical phenomenon of passive collapses while anti-Zeno effect is typical active collapses; moreover, the phenomenon of dark matter may be dark-cloud effect of normal matter while the phenomenon of accelerating universe may be induced by the luminescent asymmetries of bright celestial bodies.


2021 ◽  
pp. 014459872110558
Author(s):  
Chunhua Zhang ◽  
Dengming Jiao ◽  
Ziwen Dong ◽  
Hongyu Zhang

Risk assessment is an effective method of accident prevention and is vital to actual production. To reduce the risk of mining accidents and realize green and sustainable coal mining, a coal and gas outburst risk assessment method based on the improved comprehensive weight and cloud theory is proposed. The proposed method can effectively solve problems of fuzziness and randomness, index weight deviation, and correlation between indexes in risk assessment, as well as improve the accuracy and rationality of assessment. Nine influencing factors that correspond to coal seam occurrence and geological characteristics, coal seam physical characteristics, and gas occurrence characteristics are selected to establish the risk assessment index system of coal and gas outburst. Using the improved group G1 method and improved CRITIC method to obtain the subjective and objective weights, the ideal point method is used to obtain the comprehensive weight. Using the normal cloud model of cloud theory and the comprehensive weight to assess engineering examples 1–2, the No. 3 coal seam of a mine in Shanxi, and the 21 coal seam of a mine in Henan, the risk grade of coal and gas outburst is determined and then compared with the assessment results obtained from the engineering examples and the actual situations of the above mentioned coal seams. The results show that the coal and gas outburst risks of engineering examples 1–2, No. 3 coal seam, and 21 coal seam are of grades IV, IV, II, and IV, respectively. The No. 3 coal seam and 21 coal seam belong to lower and higher risk categories, respectively. The assessment results are consistent with the actual situation of the coal seams, thereby confirming the rationality and accuracy of the proposed method. This study expands the methods of coal and gas outburst risk assessment and facilitates the formulation of effective preventive measures.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaohui Liu ◽  
Manyin Zhang ◽  
Zhizhong Sun ◽  
Huyuan Zhang ◽  
Yimin Zhang

AbstractThe comprehensive evaluation of pipeline loess collapsibility risk is a necessary means to control the safety risks of pipelines in the collapsible loess section. It is also one of the critical scientific bases for risk prevention, control, and management. The comprehensive evaluation system of cloud theory consists of quantitative and qualitative indexes, and the evaluation system has the characteristics of randomness and fuzziness. In view of this problem, the standard qualitative and semi-quantitative evaluation methods have intense subjectivity in dealing with the uncertainty problems such as randomness and fuzziness of the system, the cloud theory, which can effectively reflect the randomness and fuzziness of things at the same time, is introduced. The state scale cloud and index importance weight cloud of pipeline loess collapse risk are constructed by the golden section method. The uncertainty cloud reasoning process of the quantitative indexes and the expert scoring method of the qualitative indexes are proposed. The comprehensive evaluation model of loess collapsibility risk of oil and gas pipeline is established, and the engineering example is analyzed. The complete evaluation results of 10 samples to be evaluated are consistent with the results of the semi-quantitative method and are compatible with the actual situation. The evaluation process softens the subjective division of index boundary, simplifies the preprocessing of index data, realizes the organic integration of quantitative and qualitative decisions, and improves the accuracy, rationality, and visualization of the results.


2021 ◽  
Author(s):  
Xiaohui Liu ◽  
Manyin Zhang ◽  
Zhizhong Sun ◽  
Yimin Zhang

Abstract The comprehensive evaluation of pipeline loess collapsibility risk is a necessary means to grasp the safety risks of pipelines in the collapsible loess section, and it is also one of the key scientific basis for risk prevention, control and management. The comprehensive evaluation system of cloud theory consists of quantitative and qualitative indexes, and the evaluation system has the characteristics of randomness and fuzziness. Aiming at the problem that the common qualitative and semi-quantitative evaluation methods have strong subjectivity in dealing with the uncertainty problems such as randomness and fuzziness of the system, the cloud theory, which can effectively reflect the randomness and fuzziness of things at the same time, is introduced, and the state scale cloud and index importance weight cloud of pipeline loess collapse risk are constructed by golden section method. The uncertainty cloud reasoning process of the quantitative indexes and the expert scoring method of the qualitative indexes are proposed. The comprehensive evaluation model of loess collapsibility risk of oil and gas pipeline is established and the engineering example is analysed. The comprehensive evaluation results of 10 samples to be evaluated are basically consistent with the results of semi-quantitative method, and are consistent with the actual situation. The evaluation process softens the hard division of index boundary, simplifies the index data pre-processing, realizes the organic integration of quantitative and qualitative, integrated decision-making, and improves the accuracy, rationality and visualization of the results.


Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Bingyou Jiang ◽  
Bo Ren ◽  
Mingqing Su ◽  
Bao Wang ◽  
Xin Li ◽  
...  

In order to scientifically and reasonably assess the risk of water inrush from the coal seam floor, considering the influence of natural environmental factors such as hydrogeology, mining, and human intervention, the PSR model of ecosystem health evaluation was introduced, and the risk evaluation indicator system of water inrush from the coal seam floor was established. In order to solve the randomness and fuzziness of water inrush event evaluation, the evaluation model is constructed based on extension cloud theory and is applied in the 12123 working face of Pan Er coal mine of Huainan Mining Group. The application results show that the evaluation results are basically consistent with the actual situation, which shows that the model can be used in the actual evaluation work and is scientific.


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