Abstract: Wheel set longitudinal vibration is a self-excited vibration when railway vehicle is running on the track, which is one of the important reasons of wheel tread spalling problem, and will cause the dynamic performance worse of the vehicle. To investigate the happen mechanism of the wheel set longitudinal vibration, the 7 degree of freedoms wheel set longitudinal vibration model which considers the torsion vibration of the wheel axle was set up based on Matlab. From the point of view of frequency and vibration, put forward one kind of forecast method of the happen of wheel set longitudinal vibration. Wheel set longitudinal vibration will lead car body to suffer an impact in the longitudinal direction and this would cause car body tremble and have a big vertical vibration. Take the locomotive which has severe wheel tread spalling problem running on the Kunming meter track for example to test the effect of the wheel set longitudinal vibration theory to solve the wheel tread spalling problem. Solve wheel tread damage from the aspect of dynamic is an evolution method and Wheel set longitudinal dynamic is the extension of the wheel/rail dynamic.
Abstract: Generally, a cell can trigger its self-defense mechanism in response to genomic stress under acute perturbations from outer environment. To investigate the dynamic kinetics of cellular repair mechanisms in fighting against genomic stress, a mathematical model of representing and analyzing DNA damage generation and repair process is proposed under acute Ion Radiation (IR) by using the Kinetic Theory of Active Particles (KTAP). In this paper, we focus on describing a mathematical framework of Cellular Repair System (CRS). We also present the dynamic processes of Double Strand Breaks (DSBs) and Repair Protein (RP) generating, DSB-protein complexes (DSBCs) synthesizing, and toxins accumulating under continuous radiation time.
Abstract: In this paper, a load transportation system in platforms or suspended by cables is considered. It is a monorail device and is modelled as an inverted pendulum built on a car driven by a DC motor. The governing equations of motion were derived via Lagrange’s equations. In the mathematical model we consider the interaction between the DC motor and the dynamical system, that is, we have a so-called non-ideal periodic problem. The problem is analysed and we also developed an optimal linear control design to stabilize the problem.
Abstract: In order to acquire high-quality knowledge used in production decision expert systems, a production decision knowledge acquisition method based on interactive simulation was proposed. Key technologies of interactive simulation modeling and expert decision data evaluating were studied in detail. Taking the line switching decision of a motor engine production line as an example, the method was practiced and validated. The case study shows that the data acquisition method based on interactive simulation can effectively optimize the production performance.
Abstract: Web server aims to service clients sensitively and clients wish to explore web sites at fast bandwidth. Nevertheless, sometimes users can only get the web content at a slow response due to the slow communication. Using data buffering technique, web cache provides clients an alternative way to acquire the web content from web server at low cost and high bandwidth. Using web cache technique, users can get fast response at low communication cost. When quantities of data are buffered to the cache server, cache policy becomes an important factor which can clearly affect the performance efficiency. Our contribution is that we take full account of the user's visiting action and redesign the cache policy. Based on this, we compare our policy (UVA) with existing method (LFU) through series of experiments. The results show that our method can efficiently improve cache hit rate.
Abstract: The objective of this paper is optimization mixing parameters in terms of mixing process of polymer nanocomposites using Taguchi method. Considering the mixing parameters such as rotational speed, mixing temperature and mixing time were performed to reveal the electrical conductivity data. Taguchi method was used by electrical conductivity analyses based on three level factorial designs. Orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, and the analysis of variance (ANOVA) were utilized to find the optimal levels and the effect of mixing parameters on electrical conductivity. Confirmation analysis measurements with the optimal levels of mixing parameters were carried out in order to show the optimum electrical conductivity of Taguchi method. The result shows that Taguchi method is effective in solving the quality problem occurred on the mixing parameters of the polymer nanocomposites.
Abstract: This paper presents a non-linear numerical investigation of surface cracks in round bars under tension stresses by using ANSYS finite element analysis (FEA). Due to the symmetrical analysis, only quarter finite element (FE) model was constructed and special attention was given at the crack tip of the cracks. The surface cracks were characterized by the dimensionless crack aspect ratio, a/b = 0.6, 0.8, 1.0 and 1.2, while the dimensionless relative crack depth, a/D = 0.1, 0.2 and 0.3. The square-root singularity of stresses and strains were modeled by shifting the mid-point nodes to the quarter-point locations in the region around the crack front. The proposed model was validated with the existing model before any further analysis. The elastic-plastic analysis under tension loading was assumed to follow the Ramberg-Osgood relation with n = 5 and 10. J values were determined for all positions along the crack front and then, the limit load was predicted using the J values obtained from FEA through the reference stress method.
Abstract: This paper presents a non-linear numerical investigation of surface cracks in round bars under bending moment by using ANSYS finite element analysis (FEA). Due to the symmetrical analysis, only quarter finite element (FE) model was constructed and special attention was given at the crack tip of the cracks. The surface cracks were characterized by the dimensionless crack aspect ratio, a/b = 0.6, 0.8, 1.0 and 1.2, while the dimensionless relative crack depth, a/D = 0.1, 0.2 and 0.3. The square-root singularity of stresses and strains was modeled by shifting the mid-point nodes to the quarter-point locations close to the crack tip. The proposed model was validated with the existing model before any further analysis. The elastic-plastic analysis under remotely applied bending moment was assumed to follow the Ramberg-Osgood relation with n = 5 and 10. J values were determined for all positions along the crack front and then, the limit load was predicted using the J values obtained from FEA through the reference stress method.