Advanced Materials Research Vols. 433-440

Abstract: A new method of rolling prediction for gas emission based on wavelet neural network is proposed in this paper.In the method, part of the sample data is selected, which length is constant,and the data is reselected as the next prediction step.Then a wavelet neutral network is adopted to prediction which input data is rolling,the sequence model of rolling prediction is thus constructed.Simulation results have proved that the method is valid and feasible.

Abstract: Electro-technical officer will be introduced and as a mandatory rating on board in the STCW78/10 amendments, the article introduces the origin and requirement of the ETO, analysis the impact on maritime authorities, ship management company and education and training institutions of navigation and puts forward some countermeasures, as well as soon as possible to provide the reference for our country to perform convention.

Abstract: Joint Probabilistic Data Association has proven to be effective in tracking multiple targets from measurements amidst clutter and missed detections. But the traditional Joint Probabilistic Data Association algorithm will cause track coalescence when the targets are parallel neighboring or small-angle crossing. To avoid track coalescence, a modified Joint Probabilistic Data Association algorithm is proposed in this paper. An exclusive measurement is defined for every target in the new algorithm. The exclusive measurement of a target is one measurement which associates with the target and has the maximum associated probability. The associated events of the exclusive measurement with other targets will be pruned, which resists two or more targets share the same measurement as a key measurement and avoids track coalescence. The simulation results show that the new algorithm can effectively solve track coalescence problem in all kinds of scenarios and keep a high tracking performance.

Abstract: Voice over Internet Protocol (VoIP) is an important service with strict Quality-of-Service (QoS) requirements with in wireless local area networks. The popular Distributed Coordination Function (DCF) of IEEE802.11 Medium Access Control (MAC) protocol adopts Multiplicative Increase and linear Decrease procedure to reduce the packet collision probability in WLANs. In DCF, the size of contention window is doubled upon a collision regardless of the network loads. This paper presents an enhanced DCF scheme to improve the QoS of VoIP in WLANs. This scheme applies a threshold of the collision rate to switch between two different functions for increasing the size of contention window based on the status of network loads. The performance of this scheme investigated and compared to the original DCF using the network simulator NS-2. Under the high traffic loads the packet loss probability decreases with the enhanced DCF compared to the original DCF. Some other parameters like throughput and access delay is decreased with the enhanced DCF.

Abstract: The similitude problem for the simulation of orbits under the central gravity deviation is investigated. The dynamic models are developed with consideration of the magnitude deviation and the orientation deviation of the central gravity, respectively. Similitude theory and dimensional analysis are employed to derive the scaling laws. Since it’s often impossible to maintain complete similarity resulting from practical constraints, a metric which combines dimensional and activity analyses is given. The metric could quantify the proximity of an actual model to exact similitude. Through creating the bond graph model of the two-body problem, the activities of the states are measured. Validity of the proposed technique is proven via numerical simulations, and the results are presented and compared.

Abstract: A large prescriptive data set of wrist, metacarpal arch fingers and thumb movements has been collected using twenty-four 4mm hemispherical passive reflective markers placed on the wrist, hand and fingers. Movements of each participant were captured by a set of 6-camera infrared motion analysis system (QUALISYS) sampling at 60Hz while undertaking a clinical hand function assessment, the Southampton Hand Assessment Procedure (SHAP). Without Muscle Contraction and With Muscle Contraction versions of objects are assessed and were tested, characteristics of individual movement strategies presented and initial results have shown interesting variations that correspond with physiological and functional approaches to movement. With the whole designed system, patient can improved hand function with the result of vigorous physical activity through the SHAP procedures, from the supervision of researcher can determine the functionality of one patient’s hand and wrist which will benefit subjects with a dramatic effect on one’s daily life as we know exercise is related to better health. Using advanced software such as Visual 3D and Qualisys Tracking Manager, researcher can monitor patient’s recovery progress, with suitable angle of calculation of one’s fingers, acceptable force and velocity of one’s produced depending on age and size of hand of subjects.

Abstract: Petri net is a good tool to express production rules. To address the problem that needs to decrease false alarm rate in Intrusion Detection System (IDS), an improved fuzzy Petri net reasoning algorithm with weight factor was presented and be applied in IDS. The algorithm takes into account weight of proposition in rules and improves accuracy of detection. The reasoning process was completed with matrix computation manner based on MYCIN confidence method. It has parallel reasoning ability and improved speed of reasoning. An example illustrated correctness and rationality of improved algorithm in IDS.

Abstract: The paper is concerned with FEA procedures are now used abundantly in automotive industry. Linear static and dynamic analyses are conducted in a routine manner, and nonlinear analysis is increasingly pursued. Two analysis fields in which highly nonlinear conditions are simulated are the crash and crush analysis of complete motorcar models. The purpose of a crash analysis is to see how the car will behave in a frontal or sideway collision. In a crash analysis the crashing of a car at about 30mph and above is considered. Various crash codes have been developed based on explicit time integration, special shell elements for this specific analysis results have been compared with laboratory test data, and the simulations have proved very valuable. In crush analysis, a quite different physical phenomenon is considered. Here the purpose is to establish the ultimate strength of the car body in a static situation. The ultimate strength affects the behavior of the car under various operating conditions, such as when the car overturns in an accident. While crash analysis of cars have been carried out with mush success, a crush analysis is much more difficult to achieve. The reasons for this greater difficulty lie in the fact that a slow-speed, almost static analysis requires increased robustness and efficiency in the solution algorithms. Specifically, for the crush analysis, the shell element mush be of high predictive capability, and be robust and computationally efficient for static analyses.

Abstract: Improvement of the performance of wind turbines as a source of clean energy production depends on the ideal control. In this paper a controller design based on fuzzy logic and for partial load region of wind turbine has been discussed. Here, fuzzy logic is used as a gain scheduler for classical controller. In the structure of the Controller, feedback signal of angular velocity of generator rotor is used to adjust the torque on the generator, while the pitch angle was kept constant on the optimal value. Fuzzy rule-base of supervisory system was derived based on responses of the turbine system to the controller with various gains which lead to track the ideal power curve. Simulation results confirmed the improvement of system response in comparison to the controlling without fuzzy supervisory.

Abstract: Aiming at the fact that the distribution of evaporation duct height is easier to obtain than the original history atmospheric and hydrology data in some sensible areas, an approximate calculation method of average radar detection range of searching radar over sea from the distribution of evaporation duct height is advanced, then this method is tested. The testing result shows that the difference between this method and direct calculation is less than 20km, so this method can meet the requirement of average radar detection range and be well applied in the evaluation of radar detection ability of searching radar in sensitive areas.