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Search Results: 1 - 10 of 13665 matches for " Jinwei Fan "
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Soft Compensation for CNC Crankshaft Grinding Machine Tool
Yongjun Liu,Jinwei Fan,Wei Miao
Advances in Mechanical Engineering , 2013, DOI: 10.1155/2013/254709
Abstract: Wear and deformation CNC grinding machine tool, will be aggravated over time of which will influence the manufacturing precision. To reduce the effect, the soft compensation method by modifying NC instruction was put forward to maintain the manufacturing precision of CNC crankshaft grinding machine tool. The error sources were analyzed, the errors caused by grinding force were calculated, and the precise grinding kinematics model was deduced by the multibody kinematics. Numerical simulation and manufacturing experiment were carried out and the rank tests were taken for the manufactured crankshafts. Experiments show that the manufacturer precision of the crank can be enhanced by 63.69%, 52.06%, 42.27%, and 30.96% by soft compensation of 10 years of service life and 10?μm grinding depth, 4 years of service life and 10?μm grinding depth, 10 years of service life and 6?μm grinding depth, and 4 years of service life and 6?μm grinding depth, respectively. Soft compensation can be applied to the machine tool in which the manufacturer precision has declined and the NC instruction with compensation should be updated periodically. 1. Introduction Reliability of machine tool can be represented by two parameters of the fault probability of machine tool signed by and the defective rate of manufactured parts signed by [1]. and will be increased over time meanwhile. is affected by the ageing and degradation of the components and parts, and is affected by the wear and deformation ignoring the human and environment factors. Replacing and maintenance are good manners when is high, which is inoperative when is high. To lengthen the using life of machine tool and reduce the production cost, the soft error compensation for machine tool was proposed to maintain the machining precision and using reliability in this paper. Error model and compensation were deduced from CNC crankshaft grinding machine tool and the validity of error compensation was analyzed by statistical method. Crankshaft is used in automobile and generator widely to transform the linear movement to rotational movement. The crankshaft machining precision will affect the power performance and stabilization of the engine. So, it has important significance of researching on the machining precision of crankshaft for improving the comprehensive performance for engine. The study focus on errors settling of CNC machine tool is error measuring and identifying, kinematics and dynamics of noncircular grinding, and the compensation method. Zhu et al. proposed one method of measuring the geometrical errors by laser
Effect of Acid Treatment on Root Architecture in Seedlings of Malus hupehensis var. pingyiensis  [PDF]
Zhao Zhang, Weiguo Fan, Hongqiang Yang, Jinxu Chen, Jinwei Dong, Kejie Han, Pengfei Li, Li Wang
Agricultural Sciences (AS) , 2017, DOI: 10.4236/as.2017.810078
The purpose of this paper is to explore the effects of acid treatment on root morphology and architecture in seedlings of Malus hupehensis var. pingyiensis. The rootstock seedlings were cultured in 1/2 Hoagland nutrient solutions of different pH (pH 4, pH 4.5, pH 5 and pH 6), respectively. The parameters of root architecture were measured in the day 4, 8 and 12 with the professional WinRHIZO 2007. Compared with the control (pH 6), the treatments significantly decreased the fractal dimension, length, diameter, surface area and volume of roots in day 8 and 12, and they kept decreasing followed the increase of the acidity and treatment time. The growth of lateral roots was more susceptible to acid treatment than taproots. In addition, the acid treatment mainly inhibited the growth of rootlets, significantly decreased the proportion of rootlets that changed the composition of roots, and then simplified the space structure of roots.
Association of GSTP1 Ile105Val Polymorphism and Risk of Head and Neck Cancers: A Meta-Analysis of 28 Case-Control Studies
Juntian Lang, Xicheng Song, Jinwei Cheng, Shuwei Zhao, Jingping Fan
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0048132
Abstract: Background and Aims The Glutathione S-transferase P1 (GSTP1) polymorphism have been considered a risk modifier for developing head and neck cancer (HNC) in many studies; however, the results of such studies are inconsistent. The aim of this study was to evaluate the possible association between the GSTP1 Ile105Val polymorphism and risk of HNC. Method We performed a search in the relevant electronic database and a meta-analysis based on 28 published case–control studies that included 6,404 cases and 6,523 controls. To take into account the possibility of heterogeneity across the studies, a Chi-square based I2-statistic test was performed. Crude pooled odds ratios (ORs) with 95% confidence intervals (CIs) were assessed using both fixed-effects and random-effects models. Results The results of this meta-analysis showed that the GSTP1 Ile105Val polymorphism was not significantly associated with risk of HNC in the overall study population (pooled OR 1.00, 95% CI 0.92–1.09) or in subgroup analyses stratified by ethnicity, sample size, tumor site or publication year. Moreover, substantial evidence of heterogeneity among the studies was observed. Publication year was identified as the main cause of heterogeneity. Conclusion This meta-analysis does not support a significant association between the GSTP1 Ile105Val polymorphism and risk of HNC.
Carriage Error Identification Based on Cross-Correlation Analysis and Wavelet Transformation
Donghui Mu,Dongju Chen,Jinwei Fan,Xiaofeng Wang,Feihu Zhang
Sensors , 2012, DOI: 10.3390/s120709551
Abstract: This paper proposes a novel method for identifying carriage errors. A general mathematical model of a guideway system is developed, based on the multi-body system method. Based on the proposed model, most error sources in the guideway system can be measured. The flatness of a workpiece measured by the PGI1240 profilometer is represented by a wavelet. Cross-correlation analysis performed to identify the error source of the carriage. The error model is developed based on experimental results on the low frequency components of the signals. With the use of wavelets, the identification precision of test signals is very high.
Trace Interpolation Algorithm Based on Intersection Vehicle Movement Modeling  [PDF]
Jinwei Shen, Guangtao Xue
Wireless Sensor Network (WSN) , 2010, DOI: 10.4236/wsn.2010.211099
Abstract: Real vehicle tracking data play an important role in the research of routing in vehicle sensor networks. Most of the vehicle tracking data, however, were collected periodically and could not meet the requirements of real-time by many applications. Most of the existing trace interpolation algorithms use uniform interpolation methods and have low accuracy problem. From our observation, intersection vehicle status is critical to the vehicle movement. In this paper, we proposed a novel trace interpolation algorithm. Our algorithm used intersection vehicle movement modeling (IVMM) and velocity data mining (VDM) to assist the interpolation process. The algorithm is evaluated with real vehicle GPS data. Results show that our algorithm has much higher accuracy than traditional trace interpolation algorithms.
A lasing mechanism based on absorption boundary of gain materials
Jinwei Shi,Shujing Chen,Wenjun Fan,Xiangyu Kong,Dahe Liu,Lily Zu
Physics , 2013,
Abstract: A new kind of mechanism of lasing is investigated experimentally. It is quite different from the traditional laser with cavity and the random laser with random scattering. In this mechanism, the intensity-dependent refractive index effect and thermal lensing effects of the pump beam induce a large gradient of the refractive index in the gain material, which forms a passive equivalent boundary that provides the feedback in the lasing system. A real lasing system, a liquid disk laser, is performed, it achieves 2-D omnidirectional radiation with a high efficiency of 28%, its radiation spectral property can be explained by resonant Raman scattering.
Expressiveness of a Provenance-Enabled Authorization Logic Jinwei Hu, Huazhong University of Science and Technology, China
Jinwei Hu
International Journal of Managing Information Technology (IJMIT) , 2010,
Abstract: In distributed environments, access control decisions depend on statements of multiple agents rather thanonly one central trusted party. However, existing policy languages put few emphasis on authorizationprovenances. The capability of managing these provenances is important and useful in various securityareas such as computer auditing and authorization recycling. Based on our previously proposed logic, wepresent several case studies of this logic. By doing this, we show its expressiveness and usefulness insecurity arena.
Differential equations and logarithmic intertwining operators for strongly graded vertex algebras
Jinwei Yang
Mathematics , 2013,
Abstract: We derive certain systems of differential equations for matrix elements of products and iterates of logarithmic intertwining operators among strongly graded generalized modules for a strongly graded conformal vertex algebra under suitable assumptions. Using these systems of differential equations, we verify the convergence and extension property needed in the logarithmic tensor category theory for such strongly graded generalized modules developed by Huang, Lepowsky and Zhang.
On associative algebras, modules and twisted modules for vertex operator algebras
Jinwei Yang
Mathematics , 2014,
Abstract: We give a new construction of functors from the category of modules for the associative algebras $A_n(V)$ and $A_g(V)$ associated with a vertex operator algebra $V$, defined by Dong, Li and Mason, to the category of admissible $V$-modules and admissible twisted $V$-modules, respectively, using the method developed in the joint work \cite{HY1} with Y.-Z. Huang. The functors were first constructed by Dong, Li and Mason, but the importance of the new method, as in \cite{HY1}, is that we can apply the method to study objects without the commutator formula in the representation theory of vertex operator algebras.
Vertex algebras associated to abelian current algebras
Jinwei Yang
Mathematics , 2015,
Abstract: We construct a family of vertex algebras associated to the current algebra of finite-dimensional abelian Lie algebras along with their modules and logarithmic modules. We show this family of vertex algebras and their modules are quasi-conformal and strongly $\N$-graded and verify convergence and extension property needed in the logarithmic tensor category theory for strongly graded logarithmic modules developed by Huang, Lepowsky and Zhang.
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