Advanced Materials Research Vols. 403-408

Abstract: Composed of a variable displacement pump and a constant displacement motor, the hydrostatic driving system is a kind of closed speed control system with adjustable displacement. It is widely used in the field of engineering vehicle and other fields. Based on an analysis of the constitution and mathematical model of the hydrostatic driving system, the present study tuned PID parameters by using the critical proportioning method and the optimization method of NCD respectively. Then a kind of fuzzy adaptive PID controller was designed on the basis of the traditional PID control and the fuzzy control theory. In the controller, fuzzy logic was used to realize online self-tuning of PID parameters according to the motor speed error and its derivative, so that the system could have better adaptive ability and strong disturbance resisting performance. The dynamic simulation was made in MATLAB/SIMULINK. The simulation results show that the optimization method of NCD has better tuning effect and the response performance of the fuzzy adaptive PID controller is better than that of the classic one. Besides, it should be noted that a drawback was found about the fuzzy adaptive PID control. On the basis of fixed scale factors, a group of quantification factors is appropriate for a specific input signal, but for other signals, the response of the system is not so ideal. A method of adjusting quantification factors according to input signal was adopted to solve the above problem. Automatic adjusting of quantification factors was realized, and this could ensure ideal response to all input signals.

Abstract: This paper introduced the problem model, solution tools and innovation principles of TRIZ theory, and analyzed the characteristics of the technology contradiction. Second, the heavy breakdown phenomenon appears to vacuum circuit breaker is analyzed and researched, and through the 39 general engineering parameters to establish its problem model. Contradictory matrix is used to find inventive principles on the problem model, combined with practical problems to filter out some obvious not to meet the requirement of principle, improvement can be finally made to the vacuum circuit breaker.

Abstract: Effacement of the basal cisterns (BC) and midline shift (MLS) are two most important features clinicians use to evaluate the severity of brain compression by various pathologies. Because of its complex shape, measuring the compression of the BC is not an easy task and its standardization has not been proposed until recently. Based on this standard method, we develop a method for automatic recognition of the BC on brain CT slices. Hypodense pixels of the brain area on each slice are found with a threshold derived from its own histogram. Hough transform is then applied to find the semicircular band containing largest number of hypodense pixels within the lower-central brain. This area was recognized as the normal or abnormal BC if it fits certain rules derived from human experts. Our system is tested on patient images. We found good inter-rater agreement between the results generated by our system and those evaluated by a board-certified neurosurgeon (kappa = 0.957).

Abstract: Automatic capsule filling machine is the key filling equipment for pharmaceutical capsule preparations. Taking NJP3400 type of capsule filling machine as an example, we built its geometric model with Pro/E, with the interface module called mechpro of PRO-ADAMS, the model can be imported into ADAMS software and then research into the kinematics simulation of the machine based on its motion parameters and structure. The machine’s strength, displacement, acceleration and the association of these parameters is also analyzed. The results show that the ADAMS software can optimize the machine’s motion parameters effectively.

Abstract: Stability of the yarn unwinding directly affects the efficiency of the textile production process and the quality of the final product. A package with an optimal shape will result in an optimal shape of the balloon. In addition, the yarn tension will be small and steady even at high unwinding velocity. Computer modeling is a valuable tool in the search for the optimal package shape. We demonstrate a mathematical model for simulating the unwinding from cylindrical and conic packages. We show how the winding angle and the apex angle influence the angular velocity of the yarn during the unwinding. Since the centrifugal forces on the yarn in the balloon depend on the angular velocity, this velocity has a large influence on the tension that we wish to reduce.

Abstract: Mathematical modeling can be used to simulate the unwinding of yarn from packages of different shapes. This method can be applied to design packages that can sustain high unwinding velocities at low and steady tension in the yarn. In the case of conic packages the angular velocity of unwinding depends not only on the winding angle as is the case for cylindric packages, but also on the apex angle. We will show that the dimensionless angular velocity depends very little on the apex angle. The apex angle, however, also determines the effective radius of the package at the lift-off point, therefore the angular velocity can be proportionally higher. We will compare unwinding from a cylindrical and a conic package with equal smallest radius and show that unwinding from the conic package is faster due to higher average radius of the package at the lift-off point.

Abstract: In this paper the focus is on the logistics for a caravan of jeeps which travel in the desert. Based on the dynamic program principle, the maximum distances for the caravan when only a part of the jeeps should return and when all drivers should return is obtained. The optimal sequence for the expedition problem as well as the optimal time for the maximum distance is also carefully studied and presented.

Abstract: There have been many growing learning materials in Internet. With the popularization of the Internet, digital learning has become a new method of knowledge acquisition. The range of electronic resources from online databases to e-books and e-journals, different resources gains in different service providers. More and more people like to take the digital courses to discuss the topics or the issues which they are interested. Online course has become an important knowledge exchange platform in virtual world. Personal knowledge maps can follow the research interests of learners and learning process as learners need a wide range of electronic resources to be integrated. Currently, although a number of electronic resources will introduce by libraries. However, lack of effective organization and integrated in the single user interface, the user must learn multiple interfaces for the use of electronic resources. The personal knowledge map system has three notable characteristics. First, connect the courses and online resources. Second, visualize the learning process. Third, combine the library resources into courses. Fourth, group the students with the same learning interests.

Abstract: With the progress of a Multi Core technique, the number of processes, which are executed concurrently on the server, has been increasing. Accordingly, the amounts of data transmitted by the servers, which deliver a large amount of data to many clients like VOD servers, also have been increasing dramatically. However, the powerful interconnection networks (Myrinet [1], Infiniband [2], etc.) are expensive without exception. Then this paper proposes the low-cost (low-priced and easy-work) method to improve the bandwidth performance. The method achieves it by bringing out the hardware performance of multiple GbE ports installed on the server. Due to advents of low-priced Multi GbE Ports Card and PCI Express slots, it is easy to install multiple GbE ports to the server. In addition, the method offers equal service (bandwidth) to all clients.

Abstract: This article introduces the basic principle for the data envelopment analysis (DEA), brings forward the evaluation method for the hierarchical effectiveness of DEA .By using DEA, a comparative study of investment validity is carried out for 18 regions of Henan from 2005 to 2009.In order to achieve the ranking of investment effects in Henan regions, reveal the regional investment effect, and draw up the figure of flying wild goose of regional investment effectiveness in Henan. According to the analysis, we come up with some proposals to improve the effectiveness of the investment in Henan.