Optimization of bone drilling parameters using grey-based fuzzy algorithm

In this article a modified algorithm (grey based fuzzy algorithm) is used to optimize multiple performance characteristics in drilling of bone. Experiments have been performed with different cutting conditions using full factorial design. The quality parameters considered are temperature, force and surface roughness. Grey relational analysis (GRA) coupled with fuzzy logic is employed to obtain a grey fuzzy reasoning grade (GFRG) combining all the quality characteristics. The highest GFRG is obtained for the feed rate of 40 mm/min and the speed of 500 rpm and is the optimal level. Analysis of variance (ANOVA) carried out to find the significance of parameters on multiple performance characteristics revealed that the feed rate has the highest contribution on GFRG followed by the spindle speed. The optimum level of the process parameters obtained is validated by the confirmation experiment.     

浅析国内轿车的现状与发展对策

从中国轿车的产量、品种、知名度、安全性能、节能环保、排量等方面剖析了中国轿车的现状及存在的问题,针对这些问题提出了抓紧自主开发、发展柴油轿车、狠抓轿车的安全质量及加强新能源开发共4点发展对策,可有效改变中国自主品牌安全性差、美誉度低、能耗大、舒适性差、废气排放量大等问题。     

A probabilistic self-validating soft-sensor with application to wastewater treatment

In the wastewater treatment plants (WWTPs), soft sensors are viewed as a simple signal estimator for hard-to-measure quantities. However, the presence of unreliable data, coupled with increasing demands for measurement quality assurance, has rendered inadequate such a simplistic view. In this paper, a probabilistic self-validating soft-sensor is proposed with the capability of performing self-diagnostics, self-reconstruction and online uncertainty measurement. In this framework, data collecting for soft-sensor modeling (easy-to-measure data) is validated by a Variational Bayesian Principal Component Analysis (VBPCA) model before performing a soft-sensor model construction. By integrating Relevant Vector Machine (RVM) as a predictive model, not only prediction values are obtained, but also the credibility of information for easy-to-measure and hard-to-measure quantities can be generated. The performance of the proposed soft-sensor is validated through two simulation studies of WWTPs with different process characteristics. The results suggest that the proposed strategy significantly improves the prediction performance.     

Simulating RC beams with unbonded FRP and steel prestressing tendons

A partial interaction based analysis to simulate the behaviour of RC beams with prestressed unbonded tendons is proposed. Unlike bonded reinforcement, the strain developed in unbonded reinforcing tendons under bending is uniform along the length of the member and is thus member dependant. Conventional analysis techniques incorporate correction factors and empirical components in defining the strain developed in both the unbonded and bonded reinforcement. Being semi-empirical, the post-cracking analysis cannot directly simulate the effects of tension-stiffening on the untensioned bonded reinforcement. Accordingly, this paper presents a segmental moment–rotation approach for simulating the behaviour of RC beams with unbonded prestressed reinforcement, such that the mechanics of the approach removes the reliance on empiricisms in defining the reinforcement and unbonded tendon behaviour. Validated against experimental results, the approach is shown to accommodate concrete creep, shrinkage and reinforcement relaxation, thus enabling prestressing losses to be quantified.     

Understanding Customer Opinions From Online Discussion Forums: A Design Science Framework

Online discussion forums, which are full of user-generated content including user opinions and comments, are a potential gold mine for exploring new and useful ideas to augment competence in innovation. Companies need to systematically analyze and interpret online commentaries to enhance in-house research and design activities. To this end, a framework is proposed using a design science approach to enable automatic analysis of the content of online opinions and comments in connection with specific products, using a web lexicon established for this purpose. Furthermore, this framework is applied to an automobile as a proof-of-concept. Several nicknames for the car brand studied were created by web users, some with irony and sarcasm. A few metaphorical expressions were also used to describe product features. Engineering practitioners should recognize the importance of stylized online expressions in order to have a better understanding of customer needs and expectations through the application of this framework, which incorporates an evolutionary web lexicon.     

Precedence constrained TSP arising in printed circuit board assembly

Component placement sequencing is a challenging problem that arises in automated assembly of printed circuit boards. While for some placement machines all placement sequences are acceptable, in other cases some sequences are not allowed because of the shape of the placement head. In such cases, while the head moves down to perform a placement, it might damage a previously placed component, and the problem of determining a minimum cost and at the same time acceptable sequence leads to a Precedence Constrained Travelling Salesman Problem formulation. In this study, a solution procedure to such a formulation is developed and its implementation in a real PCB assembly environment is discussed.     

A multidimensional segmentation evaluation for medical image data

Evaluation of segmentation methods is a crucial aspect in image processing, especially in the medical imaging field, where small differences between segmented regions in the anatomy can be of paramount importance. Usually, segmentation evaluation is based on a measure that depends on the number of segmented voxels inside and outside of some reference regions that are called gold standards. Although some other measures have been also used, in this work we propose a set of new similarity measures, based on different features, such as the location and intensity values of the misclassified voxels, and the connectivity and the boundaries of the segmented data. Using the multidimensional information provided by these measures, we propose a new evaluation method whose results are visualized applying a Principal Component Analysis of the data, obtaining a simplified graphical method to compare different segmentation results. We have carried out an intensive study using several classic segmentation methods applied to a set of MRI simulated data of the brain with several noise and RF inhomogeneity levels, and also to real data, showing that the new measures proposed here and the results that we have obtained from the multidimensional evaluation, improve the robustness of the evaluation and provides better understanding about the difference between segmentation methods.     

两种生产HDPE的催化剂应用对比分析

对比分析了国产BCH催化剂与国外同类催化剂的基本物性和工业应用等方面，指出了各自的优缺点，对国产BCH催化剂今后发展和工业应用有一定指导作用。     

Eurodist全自动实沸点蒸馏仪在原油综合性能评价及腐蚀性快速评价中应用探讨

本文介绍了德国Rofa公司生产的Eurodist全自动实沸点蒸馏仪的工作原理和操作方法,并利用该仪器在实验室对原油进行蒸馏,其蒸馏的数据进行了国际间的对比,并对蒸馏的结果进行研究分析,结果表明,该仪器完全符合ASTMD2892和ASTMD5236标准方法,并且在原油评价工作中取得了很好的效果。同时对原油腐蚀性进行定性及定量分析,指导装置的腐蚀防护及监控。