Search

In modern industry, the nondestructive testing of printed circuit board (PCB) can prevent effectively the system failure and is becoming more and more important. As a vital part of the PCB, the via connects the devices, the components and the wires and plays a very important role for the connection of the circuits. With the development of testing technology, the nondestructive testing of the via extends from two dimension to three dimension in recent years. This paper proposes a three dimensional detection algorithm using morphology method to test the via. The proposed algorithm takes full advantage of the three dimensional structure and shape information of the via. We have used the proposed method to detect via from PCB images with different size and quality, and found the detection performances to be very encouraging.

With the advantage of low cost and high innovation level, Open Source Design (OSD) has become an effective way to provide diverse products with high customer satisfaction by open group intelligence. Based on literatures and best practice of the successful OSD communities, this paper classified open source community into three types: open source hardware, public investment, and personality customization. According to the process analysis of these three kinds of communities, various operation mechanisms are investigated and presented respectively. The classification and the operation mechanisms proposed in this paper can help OSD community to make rational decision in their software development process, as well as to improve the outcome and innovation efficiency of the communities.

In order to analyze human error how to have effect on manufacturing cell and improve manufacturing efficiency from operators’ point of view, manufacturing cell human error simulation model based on the principle of human-machine integrated is proposed firstly. The realized process of manufacturing cell simulation model is detailed described. After that, human behaviors in manufacturing cell were analyzed and realization mechanisms of main model were introduced. Finally, applied above model and theory in a motorcycle manufacturing cell and simulated various human errors. The simulation result shows that human errors have significant effect on evaluating manufacturing cell performance and the influence degree increased along with the possibility of human make errors. As a result, different production mode should be adopted according to different configuration scheme of organization and personnel stability.

with the increasing proportion of wind power in whole power system ,the influence between wind power system and grid become more and more seriously ,so it is great important to research how to keep the connection between the wind power system and grid when grid voltage drops .The paper presents a new method to realize the low voltage ride - through (LVRT) of DFIG by using dynamic voltage restorer (DVR). Once the grid voltage drops,DVR will be put into use and produce compensation voltage to keep the stator side voltage steady .And it also can stop operation after the fault resolution.The paper builds a simulation model of DFIG and gives simulation results on PSCAD/EMTDC platform .

For the multi-sensor descriptor system with correlated measurement noises and same measurement matrix, the reduced-order sub-systems are obtained, applying singular value decomposition method. And measurements of every sensor are transformed to the measurement of one state component. For this new reduced-order normal system, the new fused measurement can be obtained applying the weighted least squares method. Then, the weighted measurement fusion Kalman filter and its filtering error variance are presented, applying a single Kalman filter. This method avoids computing the cross-variances among all local filters, compared with the state fusion Kalman filtering algorithm. And the accuracy of this fused filter is higher than that of local filter and state fusion Kalman filter. A simulation example verifies its effectiveness.

Business processes existed in every stage of the product life cycle. A lot of knowledge resources were carried in the business processes. The main purpose of business process modeling was to manage knowledge resources. It laid the foundations for the allocation of knowledge resources. To solve the problems of uncertainty and complexity of the management of knowledge resources, this paper studied the modeling form of knowledge resource allocation oriented business process and discussed the integration mode of knowledge resource and the business process. After the modeling process, the business process models were described from business logic relation, scope, time, cost, standard, material resources, tool and human resource. The relating knowledge resource was also determined during the modeling process, which would be used for the allocation of knowledge resources.

Clamping unit is an important component of injection molding machine. The clamping force and the clamping speed of clamping unit not only effect on the quality of molding products, but also determine the cyclic number. The large force amplification and large stroke ratio can reduce energy consumption and improve the productive efficiency. In this article, force amplification ratio and stroke ratio were used as the optimization goals. Non-dominated sorting genetic algorithm was used as the optimization method. The optimization result was better than the original design. So this article provides a reference for the same or similar product’s optimization.

To decrease the difficulty of business process modeling, the domain-specific modeling (DSM) method and the frame of model driven architecture (MDA) were discussed in this paper. By applying DSM and MDA, the meta-model consisting of domain schema and domain template was established to simplify the business process. Then the character property, relationship property and operation of business-process-oriented DSM (BP-DSM) meta-model were described. The meta-model and application template would be consummated by continuous instantiation and abstraction of the domain concepts. By extracting and accumulating a large number of enterprises' templates within the same industry, the industry-oriented model template would be ultimately established.

With the development of economic globalization, knowledge management system plays more and more important role in modern enterprises. Knowledge management includes many aspects such as knowledge modeling, knowledge acquisition, knowledge allocation, knowledge sharing and etc. However, currently existing researches mainly focused on the personal knowledge modeling (i.e., carrier modeling) and business process modeling, but rarely provided the integrated tools to solve the problem of knowledge allocation. This paper proposes a multi-carrier oriented knowledge allocation scheme, which is based on business process modeling. The details of the proposed system have been discussed.