Applied Mechanics and Materials Vols. 195-196

Abstract: These In order to overcome the behindhand and inefficient design of potato diggers, feature-based parametric modeling software Autodesk Inventor was used for the modeling of potato diggers. The swing sieve, movement simulation with ADAMS was carried out. The complex velocity acceleration and displacement curves were analyzed. Collision pressure curves were analyzed too. νis less than or equal to 500 mm/s, and αis more than or equal to 2.5m/s2, and less than or equal to 20m/s2. Test results indicated that Collision pressures of small and medium tubers are 120 Newton and 250 Newton respectively, which are all smaller than damaging pressure. Potato can be transferred freely and damage rate is less than or equal to 4% when the frequency is 5.5Hz and the swing is 30mm. It satisfies the design request.

Abstract: Biomedical computer simulation can help researchers to recognize the regularities of living systems, In the paper, The modeling and simulation of ventricular cell action potentials, Purkinje fiber action potentials and pacemaker activities of sino-atrial node cells were performed. Reconstruction and analysis to the changes of the electrical activities in myocardial cells by modulating the environment factors.

Abstract: The complexity of taxi operation system grows out of the inherent dynamics and randomness of taxi services. A simulation model of cruising taxi operation system is presented, through which, the dynamic features of the taxis 24-hour available service can be recurred. A new method of determining the system optimal taxi fleet size is developed. These are helpful to taxi supervisor for providing better service.

Abstract: The structure of perforation plate had a substantial effect on the water conductivity of plant vessels. As the microscopic structure of vessel and perforation plate is highly complex, it is very difficult to numerically solve the flow equations. The effects of perforation plate structure on water flow in plant xylem vessels were studied using CFD (computational fluid dynamics) approach, the calculation results were used to estimate the effects of the perforation plate on conductance. Results showed that simple plate provided less resistance than scalariform plate. The resistance to flow through the perforation plate increased as the plate angle increased (giving same number of pores). Increasing the pore size would reduce the resistance along the modeled vessel. The results also showed that gravity had hardly effect on flow characteristics in micro vessels of plant and nearly can be neglected.

Abstract: In the present study, on the basis of our previous study on the relationship between the resistivity and structure of the live human skull, a 2D simulation model of human skull with inhomogeneous resistivity distribution was successfully obtained from CT image. The results showed that the˰̻̼̼̓ͅ˰̵̹̹̹͉͂̓̓̈́͆̈́˰͇̱̓˰̷̶̹̹̹̳̱̼͉̓̾̾̈́˰̸̷̵̵̹̾̿̽̿̾̿̓ͅ˼˰̴̱̾˰̸̵̈́˰̵̱̼͆̓ͅ˰̶̿˰̻̼̼̓ͅ˰̵̹̹̹͉͂̓̓̈́͆̈́˰̶̿͂˰̸̹̈́̓˰̵̳̹̓̈́̿̾˰̷̵̴̱͂̾˰̶͂̿̽˰̅̇̈̂˰̈́̿˰́̅̀̃̄Ω˾̳̽˾˰ In this study, we explored the method of establishing the head simulation model with real resistivity distribution of human skull, which provided feasibility for future application and should be meaningful for the improvement of the accuracy of the studies on bioelectro-magnetic effects and EIT of the head.

Abstract: This paper analyzes the PHY layer of IEEE 802.11 standards for a variety of transmission rate, after learned that MAC layer does not provide for its adaptive approach. With the study of various adaptive algorithms, the SAARF protocol based on simulated annealing algorithm is proposed on MAC Layer rate adaptation, which can adaptively adjust transmitting rate. Compared with ARF (Auto Rate Fallback) protocol, SAARF can more effectively improve the throughput from the simulation results.

Abstract: It is needed to realize high resolution two dimensional (2D) direction of arrivals (DOA) estimation in determining the location of the mobile with high accuracy. In this paper, the problem of estimating the 2D DOA using uniform circular array (UCA) is investigated. Performance of 2D DOA estimation based on the real-valued unitary transformation MUSIC algorithm for UCA is presented, especially focusing on DOA estimation of multiple correlated signals.Then the validations of Unitary Transformation MUSIC algorithm are performed based on the measurement data in a wireless location system.

Abstract: Stability and output signal quality are two important indicators to evaluate the performance of a repeater.A high gain is also the basic requirement of repeater.This paper first proposes a feedback interference cancellation repeater scheme, and then the scheme is simulated on simulink.The result shows that the proposed scheme is able to cancel the feedback interference and guarantee the stability and output signal quality of repeater. Besides, it confirms that stability and output signal quality have some relation with the repeater gain G, the order of estimated channel filter N and the introduced delay. Finally, the approach of variable gain effectively increases the repeater gain, and appropriate selection of the gain makes it possible to avoid the output signal quality deterioration.

Abstract: In this paper, we set up the model of downlink for Time Division synchronous Code Division Multiple Access (TD-SCDMA), and present link level simulation to TD-SCDMA mobile terminal smart antenna system. By carrying on performance simulation in system bit error rate between dual-unit antenna and single-unit antenna, we can validate the advantage of dual-unit smart antenna. Besides, we analysis the mobile terminal smart antenna may influenced by many factors, such as distance of two antenna, moving speed, the number of multi-path and user and so on, solve the contradiction between miniaturization of mobile terminal smart antenna and independence between antenna, and provide a valuable design reference to commercialize the limited frequency spectrum resource.

Abstract: Modeling the radio channel has historically been one of the most difficult parts of mobile radio system design. Channel modeling is the basis for the high-level network planning process (antennae heights, frequency assignment, base station subsystem parameter set, network architecture, etc... ). In this contribution, we will compare two of the most important outdoor macro-cell models, COST 231-WI model and ECC-33 model with simulation and measurement. The measurement is taken in urban areas.