52 research outputs found
Reliability Technology Based on Meta-Action for CNC Machine Tool
Computer numerical control (CNC) machines are a category of machining tools that are computer driven and controlled, and are as such, complicated in nature and function. Hence, analyzing and controlling a CNC machine’s overall reliability may be difficult. The traditional approach is to decompose the major system into its subcomponents or parts. This, however, is regarded as not being an accurate method for a CNC machine tool, since it encompasses a dynamic working process. This chapter proposes a meta-action unit (MU) as the basic analysis and control unit, the resulting combined motion effect of which is believed to optimize the CNC’s overall function and performance by improving each meta-action’s reliability. An overview of reliability technology based on meta-action is introduced
Research on Key Quality Characteristics of Electromechanical Product Based on Meta-Action Unit
Electromechanical products have many quality characteristics, representing their quality. In addition, there are long-existed quality problems of electromechanical products, such as poor accuracy, short precision life, large fluctuations in performance, frequently failing, and so on. Based on meta-action unit (MU) for electromechanical products, this book chapter proposes a key quality characteristic control method, which provides theoretical and technical support for essentially guaranteeing the complete machine’s quality. The formation mechanisms of MU’s four key quality characteristics (precision, precision life, performance stability, and reliability) are studied. Moreover, we introduce an overview of key quality characteristic control methods based on MU. The complex large system research method of “decomposition-analysis-synthesis” is adopted to study these key science problems
A new Agkistrodon halys venom-purified protein C activator prevents myocardial fibrosis in diabetic rats
Aim To assess the effects of protein C activator (PCA) from
Agkistrodon halys snake venom on cardiac fibrosis in streptozotocin
(STZ) induced diabetic rat model, and investigate
the mechanisms of its action.
Methods PCA was identified by one-dimensional reversed
phase liquid chromatography – mass spectrometry/mass
spectrometry. Male Sprague-Dawley rats (120-140 g) were
randomly assigned to negative control (NC) and diabetic
group. Diabetes was induced by STZ in high-fat diet fed
rats. Diabetic group was subdivided into three groups: diabetic
group (DM), diabetic group treated with PCA (0.5, 2,
and 8 mg/kg), and diabetic group treated with metformin
(5 mg/kg, positive control). NC and DM groups received
the same volume of distilled water. Left ventricular mass
index (LVWI) and collagen volume fraction were measured
by hematoxylin and eosin and Masson staining. Transforming
growth factor beta-1 (TGF-β1) and interleukin 1 beta
(IL-1β) levels were determined by enzyme-linked immunosorbent
assay.
Results The diabetic rat model was successfully established
by STZ induction and high-fat diet. Glucose level,
LVWI, TGF-β1 and IL-1β level, and collagen volume fraction
were significantly reduced in diabetic rats treated by PCA
in a dose-dependent manner (P < 0.050), especially in the
high dose (8 mg/kg) group (P < 0.010), compared to diabetes
group. The high dose PCA had the same effect as
metformin positive control in reducing the level of fasting
blood glucose. PCA decreased the expression of MMP-2
and reduced that of TIMP-2.
Conclusion Our results indicate that PCA has anti-fibrotic
effects and that it may be used to treat myocardial fibrosis
Role of the Hypoxia-inducible factor-1 alpha induced autophagy in the conversion of non-stem pancreatic cancer cells into CD133+ pancreatic cancer stem-like cells
Un graphe des liaisons fonctionnelles et une fonction coût basé sur le processus de fabrication pour la cotation et le tolérancement fonctionnels
Reliability Modeling of Electromechanical System with Meta-Action Chain Methodology
To establish a more flexible and accurate reliability model, the reliability modeling and solving algorithm based on the meta-action chain thought are used in this thesis. Instead of estimating the reliability of the whole system only in the standard operating mode, this dissertation adopts the structure chain and the operating action chain for the system reliability modeling. The failure information and structure information for each component are integrated into the model to overcome the given factors applied in the traditional modeling. In the industrial application, there may be different operating modes for a multicomponent system. The meta-action chain methodology can estimate the system reliability under different operating modes by modeling the components with varieties of failure sensitivities. This approach has been identified by computing some electromechanical system cases. The results indicate that the process could improve the system reliability estimation. It is an effective tool to solve the reliability estimation problem in the system under various operating modes
Quality characteristic association analysis of computer numerical control machine tool based on meta-action assembly unit
As everyone knows, assembly quality plays a very important role in final product quality. Since computer numerical control machine tool is a large system with complicated structure and function, and there are complex association relationships among quality characteristics in assembly process, then it is difficult and inaccurate to analyze the whole computer numerical control machine tool quality characteristic association at one time. In this article, meta-action assembly unit is proposed as the basic analysis unit, of which quality characteristic association is studied to guarantee the whole computer numerical control machine tool assembly quality. First, based on “Function-Motion-Action” decomposition structure, the definitions of meta-action and meta-action assembly unit are introduced. Second, manufacturing process association and meta-action assembly unit quality characteristic association are discussed. Third, after understanding the definitions of information entropy and relative entropy, the concrete meta-action assembly unit quality characteristic association analysis steps based on relative entropy are described in detail. And finally, the lifting piston translation assembly unit of automatic pallet changer is taken as an example, the association degree between internal leakage and the influence factors of part quality characteristics and mate-relationships among them are calculated to figure out the most influential factors, showing the correctness and feasibility of this method
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