Advanced Materials Research Vol. 717

Abstract: The wide spread of cloud services has increased the demand for high performance storages. There have been various research efforts to improve performance by combining HDDs and SDDs in a hybrid form because the price per unit capacity of SSDs is higher than that of HDDs. A method that exploits the characteristic of content locality has been proposed and it reduces sizes of data by using delta encoding. However the method has limitations if data has low content locality. This paper modifies the method to overcome such limitations. The proposed method is able to reduce the overhead of delta encoding by skipping the encoding if data are found to have low locality. Instead, it utilizes caching to improve the IO performance of such data. Experiment results show that the performance of the proposed method is at least 20% higher than the original scheme.

Abstract: Proper maintenance of hydraulic equipments has a great significance to increase ratio of perfectness and utilization, ensure the quality of the project, extend service life, improve production efficiency and reduce production costs. The authors in this paper discuss the scientific measures to keep equipments in good condition and ensure workplace safety from the angle of hydraulic systems maintenance. It has reference value for proper care and maintenance of hydraulic systems on machine tools in the factorys.

Abstract: Earphone use has skyrocketed due to the widespread dissemination of portable acoustic-apparatus. As the result, hearing loss due to noise-induced is becoming a big social problem. As the existing method, warning message is only used to prevent the hard of hearing according to the earphone use. However, it is hard for users to know the effect of the hours of earphone use and volume on their hearing, and control the earphone use by themselves. Therefore, in this paper, the method is suggested that users measure the effect of the time and volume of earphone use on their hearing with the simple experimental equipment and program. The method suggested in this paper is based on the simple experimental equipment to set up the similar environment to the real ear, and the program to find out the effect on hearing with the measured data.

Abstract: In order to promote the phased array technology for the application of weld inspection, the advantage of phased array technology was introduced and the application of rails welding inspection with phased array technology was also introduced. Through detecting nature and machining flaws of aluminum-themic welding of rails, contrast to results of conventional ultrasound test, validate the effectiveness of ultrasonic phased array method, concluding characteristics of ultrasonic phased array method for the aluminum-themic welding of rails. From the result of application, the efficiency of weld inspection could be greatly improved and the inspection cost could be greatly reduced by phased array technology.

Abstract: As one of the most widely used energy storage systems, lithium-ion batteries are attracting more and more attention, and the estimation of lithium-ion batteries remaining useful life (RUL) becoming a critical problem. Generally, RUL can be predicted in two ways: physics of failure (PoF) method and data driven method. Due to the internal electro-chemical reactions are either inaccessible to sensors or hard to measure; the data-driven method is adopted because it does not require specific knowledge of material properties. In this paper, three data-driven algorithms, i.e., Support Vector Machine (SVM), Autoregressive Moving Average (ARMA), and Particle Filtering (PF) are presented for RUL prediction. The lithium-ion battery aging experiment data set has been trained to implement simulation. Based on the RUL prediction result, we can conclude that: (1) ARMA model achieved better result than SVM, however, the result shows a linear trend, which fail to properly reflect the degradation trend of the battery; (2) SVM often suffers from over fitting problem and is more suitable for single-step prediction; and (3) PF approach achieved a better prediction and reflected the trends of degradation of the battery owing to its combined with specific model.

Abstract: An Elastic solution for functionally graded cantilever beam with different modulus in tension and compression subjected to a uniform pressure on the lateral surface is investigated. The elastic modulus of tension and compression vary with the thickness as an arbitrary function, respectively, which makes the solution have a broader range of applications than the homogeneous ones. When the tension and compression modulus have the same constant value, the solution degenerates into the classical one of the cantilever beam.

Abstract: There must selection an optimal of welding parameter and condition that reduces the risk of mechanical failures on weld structures.The residual stress and welding deformation have the large impact on the failure of welded structures.To achieve the required precision for welded structures, it is required to predict the welding distortions at the early stages.Therefore, this study uses 2DFinite Element Method (FEM) to predict residual stress and strain on thick SS400 steel metal plate. A birth and death technique is employed to control the each weld pass welding. Gas Metal Arc (GMA) welding experiment is also performed with similar welding condition to validate the FE results.The simulated and experiment results provide good evidence that heat input is main dependent on the welding parameter and residual stress and distortions are mainly affected by amount on heat input during each weld-pass.

Abstract: This paper investigates theoretical flexural response of a partly overlapped piezoceramic PZT sensor and actuator pair which is attached on an infinite beam. In this study, three different overlapped lengths between the piezo sensor and actuator are considered and the response of each sensor and actuator is modeled theoretically and analyzed in the aspect of wave propagation in the beam. The out-of-plane flexural waves due to the action of the actuator are modeled in the beam and the sensor is modeled to detect the flexural waves. Because of the characteristics of the partly overlapped sensor and actuator pair, the sensor-actuator responses show specific properties after numerical analysis. In terms of frequency response function, the results of the three different partly overlapped cases display the magnitude and phase responses provide a better understanding in designing a vibration control system.

Abstract: A new fractional step method is proposed for stiff chemical reactive flows. In stiff reaction problems, wrong propagation speed of detonation wave may occur in general fraction step algorithm. During the reaction step, the proposed scheme replaces the average representation with two-reconstruction values which are obtained by predictor-corrector steps. For numerical experiments, the first-order upwind AUSM scheme and the explicit Euler method are considered. Several one-dimensional stiff reactive flows are investigated. The numerical results show that the propagation speed of the detonation wave computed by the standard method is faster than the exact solution. However, the numerical solutions by the proposed method have very good agreement with the exact solution.

Abstract: In this paper, we give a short survey and analysis on natural gas load forecasting technology using artificial neural network. Different input variables are used to compare the result of forecasting the short term gas load. The experiment results show that the BP neural network can be used to find the implicit relation among historical gas load, weather condition and the future gas load. We also conclude that the input variables have no important influence on the accurate forecast.