经济型数控化改造中抗干扰设计及实现

在进行普通机床经济型数控化改造时，不但要保证改造后机床的功能和性能，还要保证改造后的机床能够可靠、稳定地运行。为了实现改造后机床的可靠性和稳定性，阐述了普通机床经济型数控化改造中的抗干扰设计和实现。     

Improved curvature-based registration methods for high-precision dimensional metrology

Multiple measurements using various data acquisition systems are generally required to substancially enhance measurement accuracy, reliability and holisticity of freeform shapes. The obtained multiple measurement data of the shape are transformed and fused into a common coordinate system within a registration technique involving coarse and fine alignments. Standardized methods have been established for fine registration such as Iterative Closest Points (ICP) and its variants. For coarse registration, no conventional method has been adopted yet despite a significant number of techniques which have been developed in the literature to supply an automatic rough matching between data sets.The work presented in this paper proposes an improvement of registration techniques by the consideration of new discrete curvature parameters. Two main issues are addressed in this paper: the coarse registration and the fine registration. For coarse registration, two novel automated methods based on the exploitation of discrete curvatures are presented: an enhanced Hough Transformation (HT) and an improved Ransac Transformation. The use of curvature features in both methods aims to reduce computational cost. For fine registration, a new variant of ICP method is proposed in order to reduce registration error using curvature parameters. A specific distance considering the curvature similarity is combined with Euclidean distance to define the distance criterion used for correspondences searching. Additionally, the objective function is improved by combining the point-to-point (P-P) minimization and the point-to-plane (P-Pl) minimization with automatic weights. The algorithms are applied on simulated and real data performed by a computed tomography (CT) system. The obtained results reveal the benefit of the proposed improved curvature-based registration methods.     

A weakly supervised large margin domain adaptation method for isolated handwritten digit recognition

Learning handwriting categories fail to perform well when trained and tested on data from different databases. In this paper, we propose a novel large margin domain adaptation algorithm which is able to learn a transformation between training and test datasets in addition to adapting the parameters of classifier using a few or even no training labeled samples from target handwriting dataset. Additionally, we developed a framework of ensemble projection feature learning for datasets representation as a front end for our algorithm to utilize the abundant unlabeled samples in target domain. Experiments on different handwritten digit datasets adaptations demonstrate that the proposed large margin domain adaptation algorithm achieves superior classification accuracy comparing with the state of the art methods. Quantitative evaluation of the proposed algorithm shows that semi-supervised adaptation utilizing one sample per class of target domain set reduces the error rates by 64.72% comparing with a corresponding SVM classifier.     

Offshore wind turbine blades measurement using Coherent Laser Radar

To maximize aerodynamic efficiency, large-scale offshore wind turbine blades require inspection during the production stage to ensure strict tolerance requirements are met. During production, the blade is fixed at the root, restricting movement in the Z direction. X, Y, Rx, Ry and Rz remain unconstrained causing blade flex due to gravity. This deforms the blade away from the theoretical CAD blade location, causing measurement results that do not accurately represent the blade profile. Measurement error can be minimized using rigorous B-spline data alignment. Such alignment compensates for blade flex by varying the constrained Degrees of Freedom (DoF), and provides manufacturers with confidence in the design process. This paper used Coherent Laser Radar and Spatial Analyzer to establish the optimal constrained DoF variation, giving the most accurate data alignment solution. Of the constraints investigated, the optimal data transformation solution was found with a double B-spline alignment method, whilst constraining movement in Y, Z and Ry.     

(Y vs. X) or (log Y vs. X)?

The problem of choosing between the models Y = α + βX and log Y = α + βX is considered. The maximum likelihood method of Box and Cox is compared with the method of using correlation coefficients to make the choice between the two models. The methods are applied to some data from the field of metallurgy. Operating characteristics of the two methods are estimated by simulation. Over a wide range of parameters there is not much difference between the two methods, although there are parameter values for which the correlation method appears markedly inferior to the likelihood method. The likelihood method seems preferable in that it is based on a probability model; this enables the statistician to make a confidence statement about the choice of model.     

Halal status of ingredients after physicochemical alteration (Istihalah)

BackgroundHalal products are the only permissible products that can be consumed by Muslim population all over the world. Halal certification process is becoming critical due to processing advancements and conflict of opinions among various Islamic schools of thought. Multiple Halal certification standards are framed by regulatory bodies in different countries, but there is inconsistency about few issues among these standards. One such conflict is Istihalah, which deals with the alteration in physicochemical nature of food and render a non-permissible food (Haram) to an acceptable form (Halal) for Muslims. There is dire need to understand the grey areas, such as the concept of Istihalah, to develop unanimous International Halal Standards complying with the rulings of all Islamic schools of thought.Scope and approachTo understand the Istihalah, scientific and Islamic literature from various schools of thought, has been reviewed. The primary objective of this study is to explain the concept of Istihalah with respect to the physicochemical alteration of food matrix and rulings of various Islamic schools, leading to generate a consensus for international Halal certification standards.Key findings and conclusionsIstihalah is an agreed concept among Islamic schools of thought but the definition for the extent of such alteration (to be considered as Istihalah) is not agreed. This concept should not be used for Halal Certification as it may create ambiguous situation for the global acceptability and credibility of a certificate.     

BC480/22/42支撑掩护式液压支架的改造

BC480/22/42支撑掩护式液压支架由于西山矿区工况条件发生变化,且使用时间长,已造成相当数量的结构件变形,影响了支架的整体稳定性,目前支架的状况已不能满足煤矿安全生产要求,全部报废会造成资源的极大浪费,通过对该支架进行改造,使整体性能超过原BC480/22/42支架,整机性能和ZZ5200/19.5/4支架性能相当,并能通用,结构简单、经济实用.既减少了资源的浪费,又解决了资金周转压力.     

基于事故树分析的合成氨转化工段火灾爆炸危险性研究

根据合成氨生产企业转化工段生产工艺火灾爆炸事故的典型事例,建立了合成氨转化工段发生火灾爆炸的故障树。概括出导致合成氨生产企业转化工段火灾爆炸事故的基本事件,应用事故树分析中的最小割集、最小径集及结构重要度,对转化工段火灾爆炸事故进行研究,结果表明：导致转化工段火灾爆炸事故的最小割集合有43个,说明转化工段火灾爆炸事故容易发生;防止转化工段火灾爆炸事故的最小径集合有4个;通过计算基本事件的结构重要度表明,存在着火源的基本事件结构重要程度最大,其次是防爆膜选用不当和防爆膜失效等。研究结果表明,将故障树分析应用于合成氨转化工段火灾爆炸事故的分析,起到了非常好的效果,能够为环境管理者提供理论依据。     

数控化改造外圆磨床砂轮成形修整的应用

介绍了基于国产经济型开通数控系统改造的数控外圆磨床MKA1320/H的方法,针对数控外圆磨床复杂曲面砂轮的成形修整问题进行研究,通过开通数控开放式编程环境,完成了砂轮成形修整的数控编程,最后给出了完整程序。