Key Engineering Materials Vols. 474-476

Abstract: The kinematic modeling of 2P-R linkage, which is part of the differential feed mechanism of overlock machine, is built with the method of successive approximation of link length. The mechanism is analyzed with the secant method. The locus curves of center point of feed mechanism, motion curves of execution component are obtained. The performance improvement of the differential feed-dog mechanism is put forward, based on the analysis of variation behavior of feed-dog path. This has great significance for designing overlock machine and improving the working function.

Abstract: We have studied the detection of epileptic seizure by EEG signals based on embedding dimension as the input characteristic parameter of artificial neural networks has been studied in the research before. The results of the experiments showed that the overall accuracy as high as 100% can be achieved for distinguishing normal and epileptic EEG time series. In this paper, classification of multi-types of EEG time series based on embedding dimension as input characteristic parameter of artificial neural network will be studied, and the probabilistic neural network (PNN) will be also employed as the classifier for comparing the results with those obtained before. Cao’s method is also applied for computing the embedding dimension of normal and epileptic EEG time series. The results show that different types of EEG time series can be classified using the embedding dimension of EEG time series as characteristic parameter when the number of feature points exceed some value, however, the accuracy were not satisfied up to now, some work need to be done to improve the classification accuracy.

Abstract: This paper adopts the indoor artificial rapid infiltration system of simulated soil columns to deal with several water-quality indexes of wastewater from Dongfeng Ditch. The test indicates the change of several indexes, such as COD, ammonia nitrogen, total phosphorus, Cr6+ after the treatment, analyzes the influential factors and display the wastewater treatment effects of the simulation method in laboratory with different soil components and different wet- dry ratios.

Abstract: A remote network monitoring model for large-scale materials manufacturing is proposed, including five modules: center control module, data collection and fault alarm module, graph drawing module and data storage module. The center control module not only interacts with users, but also controls the other four modules to work together in harmony. According to this monitoring model, a remote network monitoring platform is designed and realized. The user can interact with the control center module through an Internet browser, and the information about the monitored manufacturing machines and devices can be displayed by means of text, chart, graphic and sound, etc. Moreover, the details about the problems or faults from the monitored objects can be obtained in time. The experimental results indicate that the network monitoring platform can accurately get the information of the monitored objects, and users can conveniently get the online running state of those monitored objects.

Abstract: Formulas of flux and power consumption of twin screw pulping extruder (TSPE) based on extrusion model deal with nearly all of geometrical and mechanical parameters of the twin screw and the material processed, they are not convenient for estimation and initial design of the machine. Adopting dimensional analysis based on similarity theory and considering the most important factors, such as outer diameter of screw, rotational speed of screw and average pressure between barrel and material processed, estimation equations of flux and power consumption of the TSPE are deduced in the paper, and the correction coefficients are determined by experiment data. The estimation results show that the estimation and theoretical results have similar changeable trend although there are some errors. The work is easy to apply in the estimation and initial design of the TSPE, and complement the design theory and method of the TSPE.

Abstract: In order to reduce the energy consumption and gear’s weight of drive system, based on electromechanical driving dynamics, the paper discussed the influence on rotary inertia of motor shaft caused by drive system of multi-shaft varying speed and its actuator, analyzed the influence on energy consumption and cycle of the motor’s startup or brake by sum rotary inertia (SRI), and explained the problems related to rotational speed of the motor and drive system design, also brought forward methods on weight reduction design (WRD) of drive system. Case studies show that in multi-shaft reduction drive, the ratio of the drive system rotary inertia on the SRI of the motor shaft is from 5.377% to 18.567%. Therefore, weight reduction of the drive system has obvious effect on lessening the energy consumption and cycle of the motor’s startup or brake. And the work of the paper offers theoretical gist for WRD of drive system.

Abstract: In order to select rational screw parameters for improving the pulping quality, efficiency and reducing specific energy, the paper studied the effects of the rotational speed of screw, lead number of reverse thread and slot width of reverse flight of the twin screw pulping extruder (TSPE) on specific energy, flux and pulping quality (reject rate, fiber length and fine component content) in the processes of extrusion mechanical pulping. The experimental results show that synthetically considering and pulping quality the efficiency, the screw rotational speed of 300 r/min–400 r/min is more appropriate. For poplar chips, the lead number should be greater than or equal to six. And for cotton stalks and wheat straws, the lead number should be no less than seven. For the combination screws of multiple extrusion zones, the slot width of the ultimate extrusion zone plays a decisive role on the fiber length. In addition, the slot width can also adjust the barrel pressure and the axial force of the screws. The work of the paper is significant for optimum design of the TSPE.

Abstract: When nanofibers could be made last century, its filtration potential was expected in a lot of professional fields, such as building industry, medical industry and Environmental protection industry. In the present study, in order to prove and explain its performances, nanofibrous membrane with given thickness was electrospun with 8% PVA solution on conventional cotton scaffold. Then by means of special air filtration test system, the filtration performances between PVA nanofibrous membrane and conventional fibrous filters were confirmed and compared. Besides, the filtration efficiencies of particles distribution 0.3-5um were attained, and at the same time, another important parameter, pressure-drops, could be observed, too. Through data analysis, the differences of filtration performances were verified. Despite the fact that nanofibrous membrane had higher pressure-drops, its filtration efficiency could reach startlingly 99% for some given particles. In succession, SEM was used to observe the particles distribution in filter, and the different filtration mechanisms were analyzed and discussed with SEMS images. Furthermore, we found that the direct inception and the inertial impact improved nanofiber filtration efficiency, while too small diameter of nanofiber induced higher pressure-drops. In general, nanofibers have huge value in air filtration application.

Abstract: The coordination of multi-enterprise production scheduling with partial information sharing is important in supply chain management. This paper proposes a multi-enterprise scheduling model based on ant colony algorithm. The model managed by agents and the enterprises interact with each other to evaluate the schedules, and build new schedules if any other enterprise is unsatisfied with the status quo. This process will repeat until all enterprises are satisfied with the schedules. Finally, the paper takes an example shows that the algorithm is effective and feasible.

Abstract: Development of information technology provides the technical support for instruction. Research on teaching-system is developed using agent technology at present. A problem based learning system is structured using multi-Agent after the characteristics of PBL is analyzed. Each agent’s function and logical structure are discussed. Composition and workflow of the system are introduced. And the last, we also made some advanced research about the key technology.