Abstract: Collision detection is a critical problem in five-axis high speed machining. Using a combination of process simulation and collision detection based on image analysis, a rapid detection approach is developed. The geometric model provides the cut geometry for the collision detection and records a dynamic geometric information for in-process workpiece. For the precise collision detection, a strategy of image analysis method is developed in order to make the approach efficient and maintian a high detection precision. An example of five-axis machining propeller is studied to demonstrate the proposed approach. It has shown that the collision detection task can be achieved with a near real-time performance.
Abstract: By comparing and analysing the model of non-iterative least squares support vector machines (LS-SVM) based on quadratic Renyi-entropy, traditional LS-SVM model and standard support vector machines (SVM) model, this paper concludes whether the number of training samples or computing time,non-iterative LS-SVM model based on quadratic Renyi-entropy are significantly better than the model of traditional LS-SVM and standard SVM model and it also proves the effectiveness of applying the concept of quadratic Renyi-entropy on financial distress prediction. At the same time, by the comparison of different point of 3 years of ST which is from 1to 2, the author concludes the forecast accuracy of 1 year ago before ST, the further distance away from the piont of ST, the lower the prediction accuracy is.
Abstract: The friction and wear behavior of Si3N4, SiC and ZrO2 sliding against M50 bearing steel under vacuum condition at various applied load were investigated. The results showed that the properties of different ceramic materials cause the difference in wear behaviors. The coefficient of friction was lowest in SiC and M50 bearing steel couple than other cases for graphitic carbon replaced carbidic carbon at the worn layer of SiC. The specific wear rate of ZrO2 was highest and the lowest was Si3N4. The ceramic ball materials have transferred on M50 bearing steel surfaces and tribofilm consistently formed on the ceramic balls wearing surfaces. Dominant wear behaviors for three structural ceramics were adhesion abrasion, plastic deformation and brittle fracture. The couple with Si3N4 and M50 showed the best operating conditions for friction and wear resistance under higher applied load.
Abstract: Short fatigue crack density evolution on specimen surface of railway LZ50 axle steel is studied experimentally by local and overall viewpoints, respectively. Results indicate that the density of effective short fatigue cracks (ESFCs) around dominant crack, which results in the specimen failure, evolutes sensitively to the changes of the dominant crack size and tip locations. In accordance with the previous criterion of ESFCs, this density evolution is more suitable for describing the intrinsic and dynamic localization and randomization of fatigue damage. At the same time, statistical deriving is applied to address the randomness of the evolution behavior. It is revealed that the density data increases with the dominant crack growth in the micro-structural short crack (MSC) regime, and keeps declining in the physical short crack (PSC) regime. Coefficient-of-variations exhibit a contrary tendency. Appropriate distribution is further determined using a previous comprehensive statistical comparison method. Random characters and quantitative measurements of the density data have been well depicted.
Abstract: Through the research on the existing problems of Chinese colleges PE major in the process of developing multimedia teaching, the paper finds out the problems in following aspects.The insufficient leading officials’ concern, the insufficient hardware facilities and equipments, lack of matching software and lower teachers’ operation ability. Moreover, it also puts forward the relevant countermeasures to promote the application and popularization of multimedia teaching methods in PE teaching. This research will further promote modern teaching reform of PE major, optimize the PE teaching class, improve PE teaching quality and plays a certain role.
Abstract: This document proposes a new type of design for protecting children safely in the car which can increase children's comfort and safety in the car. It is designed from the point of clothing that combines children clothing with car seat cover of automobile, and it may promote collaborative development of automotive industry and garment industry.
Abstract: To study the effects of temperature and thickness on forming limits of boron steel 22MnB5, Nakajima tests have been performed for the steels with thickness of 1.0mm and 1.4mm at 600°C and 700°C, respectively. The forming limit curve (FLC) of the steel at 700°C is higher than that at 600°C, and the FLC of the steel with 1.4mm is higher than that of the steel with 1.0mm. With increasing the forming temperature, the strain rate sensitive exponent m increases, and it results in a longer Swift’s diffuse instability phase and greater limit strains. The effect of thickness on yield path is different from the case at room temperature, due to the half angle of pointed Vertex, θ0, which increases with increasing of the thickness, and then the limit strains increase.
Abstract: In2S3 thin films have been prepared on heated glass substrates by ultrasonic spray pyrolysis method. Structure, surface morphology and properties of films with different S/In ratios have been investigated. XRD analysis demonstrated that as-prepared In2S3 thin films have a preferential orientation along the (220) direction and no other phases are observed. Uniformity, density, crystallinity of films were significantly affected by S/In ratios, which influence photoelectric properties of the films. In2S3 thin film is close to standard stoichiometric composition when S/In ratio is 2. Optical transmittance of films is over 90% in the visible region and its energy band gap come up to 2.46eV.
Abstract: This study is a productivity review on the literature gleaned from SSCI, SCIE databases concerning knowledge transfer research in virtual contexts. The result indicates that the number of literature productions on this topic is still growing in recent years. The main research development country is the United States. And from the analysis of the subject area, communication is the most popular subject, then engineering, multidisciplinary, and management. Concerning source title, group decision and negotiation is in the priority. Moreover the research focuses are mainly theory model and empirical research; these typical references are analyzed in detail, including limitations and future research in this field.
Abstract: This study is a productivity review on the literature gleaned from SSCI, SCIE databases concerning social network analysis in knowledge management research. The result indicates that the number of related literature is still growing especially in recent two years. The main research development country is the United States, then England and German, and from the analysis of the subject area, Information Science & Library Science is the most popular subject. Concerning source title, Knowledge Management Research & Practice is in the priority. Moreover the research focuses on this topic are mainly in close relationship with knowledge network. Typical references were analyzed in detail, including limitations and future research.