313 research outputs found

    Multipoint Optimal Minimum Entropy Deconvolution Adjusted for Automatic Fault Diagnosis of Hoist Bearing

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    Multipoint optimal minimum entropy deconvolution adjusted (MOMEDA) is a powerful method that can extract the periodic characteristics of signal effectively, but this method needs to evaluate the fault cycle a priori, and moreover, the results obtained in a complex environment are easily affected by noise. These drawbacks reduce the application of MOMEDA in engineering practice greatly. In order to avoid such problems, in this paper, we propose an adaptive fault diagnosis method composed of two parts: fault information integration and extracted feature evaluation. In the first part, a Teager energy spectrum amplitude factor (T-SAF) is proposed to select the intrinsic mode function (IMF) components decomposed by ensemble empirical mode decomposition (EEMD), and a combined mode function (CMF) is proposed to further reduce the mode mixing. In the second part, the particle swarm optimization (PSO) taking fractal dimension as the objective function is employed to choose the filter length of MOMEDA, and then the feature frequency is extracted by MOMEDA from the reconstructed signal. A cyclic recognition method is proposed to appraise the extracted feature frequency, and the evaluation system based on threshold and weight coefficient removes the wrong feature frequency. Finally, the feasibility of the method is verified by simulation data, experimental signals, and on-site signals. The results show that the proposed method can effectively identify the bearing state

    Z-number-valued rule-based decision trees

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    As a novel architecture of a fuzzy decision tree constructed on fuzzy rules, the fuzzy rule-based decision tree (FRDT) achieved better performance in terms of both classification accuracy and the size of the resulted decision tree than other classical decision trees such as C4.5, LADtree, BFtree, SimpleCart and NBTree. The concept of Z-number extends the classical fuzzy number to model both uncertain and partial reliable information. Z-numbers have significant potential in rule-based systems due to their strong representation capability. This paper designs a Z-number-valued rulebased decision tree (ZRDT) and provides the learning algorithm. Firstly, the information gain is used to replace the fuzzy confidence in FRDT to select features in each rule. Additionally, we use the negative samples to generate the second fuzzy numbers that adjust the first fuzzy numbers and improve the model’s fit to the training data. The proposed ZRDT is compared with the FRDT with three different parameter values and two classical decision trees, PUBLIC and C4.5, and a decision tree ensemble method, AdaBoost.NC, in terms of classification effect and size of decision trees. Based on statistical tests, the proposed ZRDT has the highest classification performance with the smallest size for the produced decision tree.The project B-TIC-590-UGR20Programa Operativo FEDER 2014-2020Regional Ministry of EconomyKnowledgeEnterprise and Universities (CECEU) of AndalusiaChina Scholarship Council (CSC) (202106070037)Project PID2019-103880RB-I00MCIN/AEI/10.13039/501100011033Andalusian government through project P20_0067

    Sleep duration and patterns in Chinese older adults: A comprehensive meta-analysis

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    This meta-analysis examined the mean sleep duration and patterns in Chinese older adult population. A literature search was systematically conducted covering major English (PubMed, Embase and PsycINFO) and Chinese (Chinese National Knowledge Infrastructure (CNKI), WanFang and SinoMed) databases. Data in studies with the mean and standard deviation of sleep duration and/or the proportion of short and long sleep durations in Chinese older adults were extracted and pooled using random-effects models. Subgroup analyses were conducted according to gender, region, area, survey time and sample size. A total of 36 studies with 150,616 subjects were included for analyses. The pooled mean sleep duration of 21 studies with available data was 6.82 hours/day (95% CI: 6.59–7.05 hours/day). The estimated proportions of sleep duration \u3c5 hours/day, \u3c6 hours/day, \u3c7 hours/day were 18.8% (95% CI: 1.7%–35.9%), 26.7% (95% CI: 19.7%–33.7%) and 42.3% (95% CI: 34.8%–49.8%), respectively. The pooled proportions for long sleepers were 22.6% (95% CI: 13.9%–31.4%) (\u3e8 hours/day) and 17.6% (95% CI: 12.4%–22.9%) (\u3e9 hours/day). Given the adverse effects of unhealthy sleep patterns, health professionals should pay more attention to sleep patterns in this population in China

    Digital twin rapid construction method of a mining hoisting system

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    The safe and reliable operation of the hoisting system is very important for the production of the whole mine. Therefore, it is necessary to realize the single-point global visualization and virtual remote cooperative linkage control of the mining hoisting system, so as to solve the problem that the traditional multi-point video surveillance can only cover some key components and obtain incomplete information. To solving the problem, the digital twin framework of a mining hoisting system that with the function of monitoring, control and servicing is constructed by industrial sensing, artificial intelligence, rapid modeling, cloud storage and other technologies. Based on the framework, a multi-dimensional and multi-scale digital twin rapid modeling method is proposed. Firstly, a large scale geometric model of the mining hoisting system is built by 3D laser scanning technology, filtering, Poisson 3D reconstruction and other point cloud processing algorithms. Secondly, using industrial sensor network, PLC data reading and conversion technology, the behavior model of mining hoisting system under massive data is established. Lastly the fault knowledge model of the mining hoisting system is constructed using the database technology, domain expert knowledge and cases. The multi-dimensional and multi-scale digital twin rapid modeling experiment is carried out in a mine, and the results are as follows. The efficiency of the geometric modeling method has improved 93% compared with the traditional CAD modeling method and the modeling result has great similar to the real mining hoisting system. The behavior modeling method realizes the mapping of real entity behavior without adding new sensors and without shutting down, saves a lot of cost and has strong real-time performance. The driving Scripts are written based on Unity3D software to deeply integrate behavioral model, knowledge model and geometric model. Synchronization and deduction of behavioral model are carried out based on the component level model with high fidelity of the geometric model and it can realize the non-delay cooperative linkage between virtual and real systems. Meanwhile, relevant professional knowledge in the field is triggered by real-time behavioral data to assist decision making. The establishment process of the whole digital twin model takes into account the cost and effect, which will greatly improve the operation security and intelligence degree of the mining hoisting system

    Integrated traditional Chinese and western medicine for Menopausal syndrome: Meta-analysis of randomized controlled trials

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    Background: To critically assess the evidence of integrated Chinese and western medicine for treating  Menopausal syndrome (MPS).Methods and Materials: A search across the Chinese Biomedical Medicine (CBM), Chinese National Knowledge Infrastructure (CNKI), VIP database (VIP), Wangfang database (Wanfang), PubMed and the Cochrane Library databases was conducted (up to October 31st, 2013) in commonly used integrated Chinese and western medicine therapies for menopausal syndrome. A number of Randomized Controlled Trials (RCTs) evaluating the therapeutic efficacy of integrated Chinese and western medicine in patients with PPS were included. The quality of the included studies was evaluated and a meta-analysis was performed using the RevMan5.0 software.Results: Twelve RCTs with 1155 patients were evaluated in this review. The results of meta-analysis showed that the therapy of using integrated Chinese and western medicine was significantly superior to that of western medicine alone towards improving the efficacy, relieving the clinical symptoms and decreasing follicle-stimulating hormone (FSH)levels (P<0.05), even though the effects of two treatments were the same in regulating the levels of luteinizing hormone (LH) and estradiol (E2).Conclusion: Compared to a regular treatment with western medicine alone, the therapeutic approach that utilizes integration of Chinese with western medicine can effectively improve the clinical efficacy and serum hormone levels in patients with menopausal syndrome. However, the evidence was not very strong due to the poor quality of the included studies.Key words: Integrated Traditional Chinese and Western Medicine, Menopausal Syndrome, Meta-analysi

    The use of Rheum palmatum L. In the treatment of acute respiratory distress syndrome: a meta-analysis of randomized, controlled trials

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    Background: Chinese medicine theory shows that “lung being connected with large intestine”, and the modern western medicine also shows that the lung and intestinal tract affect each other in physiological and pathological conditions. If the lung ventilation dysfunction is caused by inflammatory exudate or secretions obstruction of the small airway ventilation, blood gas partial pressure is increased and intestinal gas absorption difficulty may lead to intestinal inflation and dysfunction (Wang N et al., 2011). Rheum palmatum L. can play the roles of anti-coagulation and anti-thrombosis, and improve microcirculation through lowering the endotoxin-induced permeability of microvascular tissue, reducing tissue oedema, decreasing inflammatory exudation and necrosis, and enhancing cyto-protection mechanism (Yang TZ et al., 2014). Therefore, systemic evaluation of the evidence pertaining to the usage of Rheum palmatum L. in treating acute lung injury and acute respiratory distress syndrome (ARDS) has significant clinical significance.Materials and Methods: Various Electronic Databases CBM, CNKI, VIP, Wanfang, PubMed and Cochrane Library were searched until December 2015. Numerous randomized-controlled trials (RCTs) evaluating the efficacy of Rheum palmatum L. for the treatment of acute lung injury and acute respiratory distress syndrome were collected. The quality of the included studies was evaluated and a meta-analysis was performed using the RevMan5.0 software.Results: Eight RCTs involving 489 patients were selected for this review. The results of the Meta-analysis revealed that Rheum palmatum L. therapy, combined with routine comprehensive treatment, was significantly superior to that of routine comprehensive treatment alone, in the areas of decreasing mortality, the mechanical ventilation time, the level of interleukin-6,8 and the untoward effect, and also in improving arterial blood gas (PaO2/FiO2, PaO2) (P<0.05).Conclusion: Compared with treatment with routine comprehensive alone, Rheum palmatum L. treatment combined with routine comprehensive, has been shown to effectively decrease the mortality, mechanical ventilation time and ameliorate the arterial blood gas, the cytokine levels, and the untoward effect. However, the evidence appears not to be very compelling due to the poor quality of the original studies.Keywords: Rheum palmatum L., Western medicine therapy, ALI/ARDS, Systematic Review, Meta-analysi

    A group decision making support system for the Web: how to work in environments with a high number of participants and alternatives

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    One of the main challenges that the appearance of Web 2.0 and the overall spreading of the Internet have generated is how to tackle with the high number of users and information available. This problem is also inherited by the group decision making problems that can be carried out over the Web. In this article, to solve this issue, a group decision making support system that allows the use of a high number of participants and alternatives is presented. This method allows any number of participants to join the decision making process at any time. Furthermore, they let them provide information only about a certain subset of alternatives. The high participation rate can provide enough information for the decision process to be carried out even if the participants do not provide information about all the high number of available alternatives.This paper has been developed with the financing of FEDER funds in the project TIN2016-75850-R

    Three-step iterative methods with optimal eighth-order convergence

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    In this paper, based on Ostrowski's method, a new family of eighth-order methods for solving nonlinear equations is derived. In terms of computational cost, each iteration of these methods requires three evaluations of the function and one evaluation of its first derivative, so that their efficiency indices are 1.682, which is optimal according to Kung and Traub's conjecture. Numerical comparisons are made to show the performance of the new family. © 2011 Elsevier B.V. All rights reserved.This research was supported by Ministerio de Ciencia y Tecnologia MTM2010-18539.Cordero Barbero, A.; Torregrosa Sánchez, JR.; Penkova Vassileva, M. (2011). Three-step iterative methods with optimal eighth-order convergence. Journal of Computational and Applied Mathematics. 235(10):3189-3194. https://doi.org/10.1016/j.cam.2011.01.004S318931942351

    Iterative fixed-point methods for solving nonlinear problems: dynamics and applications

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    Alicia Cordero and Juan R. Torregrosa were partially supported by Ministerio de Ciencia y Tecnología MTM2011-28636-C02-02.Torregrosa Sánchez, JR.; Cordero Barbero, A.; Kanwar, V.; Kou, J. (2014). Iterative fixed-point methods for solving nonlinear problems: dynamics and applications. Abstract and Applied Analysis. 2014. https://doi.org/10.1155/2014/313061S201
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