THE EFFECTS OF CRYOGENIC SURROUNDINGS ON THERMAL-INDUCED DAMAGE IN LASER GROOVING OF FIBER-REINFORCED PLASTIC

The traditional cutting of fiber-reinforced plastics causes serious concern of tool wear. The merits of narrow cuts and flexible path of lasers lead to the application of the shaping operation of composite material after curing. However, laser-induced thermal damage is often produced. It leads to poor assembly tolerance and long-term performance deterioration, The current study derives the concept of laser machining in a cryogenic environment. The anisotropic heat affected zone (HAZ) associated with cryogenic parameters is experimentally and analytically investigated for both principal-axis and non-principal-axis grooving in the example of unidirectional Carbon/Epoxy laminates. In principal-axis grooving, an analytical model based on a moving point heat source with a Mirror Image Method and immersed heat source can illustrate the effect of cryogenic surrounding on HAZ, while Finite Difference Method (FDM) is applied for prediction in the case of nonprincipal-axis grooving. The results reveal that the extent of the HAZ can be reduced by the proposed use of a cryogenic environment in laser machining.     

Wind Turbine Gearbox Fault Diagnosis Based on Multi-Sensor Signals Fusion

This paper proposes a novel fault diagnosis method by fusing the information from multi-sensor signals to improve the reliability of the conventional vibration-based wind turbine drivetrain gearbox fault diagnosis methods. The method fully extracts fault features for variable speed, insufficient samples, and strong noise scenarios that may occur in the actual operation of a wind turbine planetary gearbox. First, multiple sensor signals are added to the diagnostic model, and multiple stacked denoising auto-encoders are designed and improved to extract the fault information. Then, a cycle reservoir with regular jumps is introduced to fuse multidimensional fault information and output diagnostic results in response to the insufficient ability to process fused information by the conventional Softmax classifier. In addition, the competitive swarm optimizer algorithm is introduced to address the challenge of obtaining the optimal combination of parameters in the network. Finally, the validation results show that the proposed method can increase fault diagnostic accuracy and improve robustness.     

项目管理在现代新型电力机车工程开发中的应用

从现代新型电力机车工程开发的高科技复杂性着手,介绍了项目管理在工程开发过程中应用的案例。项目管理不但确保了工程开发的成功,也给人们带来了管理上的新理念。     

反馈在认知微观材料学问题的应用

本文尝试应用“控制论”中的“反馈”概念 ,去分析微观材料学中的现象。结果指出 :环境与系统作用后 ,返回输出的信息中 ,环境与系统都可能有“质”的改变 ;应该从改变后的环境和系统的结构的信息去理解随后的现象。这是一种新反馈 ,并可联系到耗散结构理论。     

Inspection Analysis for Edge Detection of Small Objects Using CAItech''''s 3D Laser Comparator

in many industrial situations, edge detection of 3-D objects is frequently required.Typical examples are found in dimension control and machine vision applications .As technology advances, the capability of computers has greatly improved. This paper describes our system used to inspect objects and the method used to find the edges for those objects with planar and cylindrical faces from a huge set of cloudy points. First the systems are based on opto-electronic techniques and hence are non-contact. The system is designed for a small objects less than 2 x 2 x 2 cm. The edge resolution is based on the principle of spacial geometry of a triangle in the cartesian coordinate system. The system can be considered scanning linearly with a rotation stage of a mirror,on the other hand the object circumferentially rotate on a turntable. After obtained surface profile of 3-D objects,we then apply for a geometrical method to find the edges. The performance of the systems is demonstrated with different sizes test objects.     

Foreword

The mobilization of metal cations from insoluble ores by biological oxidation and complexation processes is referred to as biometallurgy.The application of biometallurgy for copper recovery was archived as early as 2600 years ago in China in A Chinese Bestiary and it was recorded as Dantong,which means extraction of copper from acid mineral water.A book called     

现代通信网的展望

本文首先回顾了通信网的形成，然后分别对其组成部分进行了讨论，从而揭示了现代通信网的发展趋势。     

Semi-Supervised Learning Based Tag Recommendation for Docker Repositories

Docker has been the mainstream technology of providing reusable software artifacts recently. Developers can easily build and deploy their applications using Docker. Currently, a large number of reusable Docker images are publicly shared in online communities, and semantic tags can be created to help developers effectively reuse the images. However, the communities do not provide tagging services, and manually tagging is exhausting and time-consuming. This paper addresses the problem through a semi-supervised learning-based approach, named SemiTagRec. SemiTagRec contains four components:(1) the predictor, which calculates the probability of assigning a specific tag to a given Docker repository; (2) the extender, which introduces new tags as the candidates based on tag correlation analysis; (3) the evaluator, which measures the candidate tags based on a logistic regression model; (4) the integrator, which calculates a final score by combining the results of the predictor and the evaluator, and then assigns the tags with high scores to the given Docker repositories. SemiTagRec includes the newly tagged repositories into the training data for the next round of training. In this way, SemiTagRec iteratively trains the predictor with the cumulative tagged repositories and the extended tag vocabulary, to achieve a high accuracy of tag recommendation. Finally, the experimental results show that SemiTagRec outperforms the other approaches and SemiTagRec's accuracy, in terms of Recall@5 and Recall@10, is 0.688 and 0.781 respectively.