Applied Mechanics and Materials Vols. 148-149

Abstract: An improved BM-algorithm in intrusion detection system was presented which can increase displacements using the next character of the substring has been matched in the main string and pattern string. Experimental results obtained by capturing network packets with the number of matches, the number of pattern moves, the number of character comparisons as the main indicators. Experimental results show that the number of matches after and before improved is equal, and the number of pattern moves decreased by about13.3% after improved, and the number of character comparisons decreased by about 15.1% after improved. This indicates that the improved algorithm improved the efficiency of pattern matching.

Abstract: The clutch control is one of the cores and most difficult issues in the development of an AMT system. In this paper the pneumatic clutch engagement characteristic is analyzed. Thereto, a simulation model of an automotive powertrain comprises a diesel engine, drivetrain and wheels driving a vehicle through tire-road adhesion are built using Matlab/Simulink. In the simulation, a refined control law of constant engine speed in part process is proposed and tested. The engaging speed and displacement of the clutch vary with the accelerate paddle opening, engine speed, clutch driven plate speed and gears according the control law. Field experiment results show that the control strategy fulfills the system requirements.

Abstract: Electrical-endurance of relay is great important work .In this paper, the composition of relay collection system and using ni_7811R achieve fpga contact collection technology based on Labview platform are introduced .This paper make contact information can be collected real- timely and transferred rapidly through dma module . It has positive significance to enhance relay quality and reliability.

Abstract: Cassava is one of the most important crops in Nakhon Ratchasima province which grows the most cassava in the Northeast of Thailand. Therefore, a large amount of cassava rhizome is left in the field after harvest. The objectives of this research were to study the feasibility of cassava rhizomes use for Dan Kwian pottery firing in the same province. The analysis consisted of physical properties, heating value and comparing firing the pottery by wood fuel and cassava rhizome. The results were that the cassava rhizomes, with moisture content of about 34.73%, had properties inferior to the woods. When the rhizomes are burned to give thermal energy to pottery products, the temperature profile of the rhizomes is similar to the profile of wood fuels. As a result, the typical quantity of rhizome required, burning time and cost are 3,627 kg, 40 hours and 1,814 baht, respectively, while the values for wood are about 2,600 kg, 34 hours and 2,600 baht, respectively. The cost of the rhizome is less than the wood by around 786 baht. Therefore, using cassava rhizome to replace wood fuel is feasible but it is necessary to control the moisture content to an appropriate level.

Abstract: In this paper, by using critical point theory, a sufficient condition is obtained on the existence of periodic solutions for a class of nonlinear second-order difference systems.

Abstract: Fuzzy disturbance observer, as an outstanding feedback controller, is an effective means to improve the accuracy and bandwidth of high precision angular tracking systems. This robust controller based on the fuzzy disturbance observer(FDO) is introduced in this paper, and the method is applied to the flight simulator system together with PD controller. Compared to the traditional method of lead and lag correction or DOB controller, this novel method based on FDO can inhibit high-frequency noise and compensate low-frequency interference better, such as frictions, and achieve better precision finally.

Abstract: This paper is concerned with crashworthiness design of a reinforced thin-walled column under oblique impact. To transform the failure mode of the column under oblique loads from low energy-absorption global bending to high energy-absorption progressive collapse, Magic Cube (MQ) approach, a systematic design approach, is employed to assist the design process: by applying time (process) decomposition, the original difficult nonlinear dynamic crashworthiness design problem is converted into a sequence of simplified linear design problems; by applying multi-domain topology optimization technique to the simplified linear design problems, the optimal configuration of the reinforcement is obtained. Numerical simulation results show that, compared with the original column with same weight, the optimal reinforced thin-walled column has higher energy absorption performance and lower initial crushing force under oblique impact.

Abstract: The oxidation of austenitic fine-grained steel TP347HFG exposed to supercritical water at 550 °C and 25 MPa with the dissolved oxygen concentration of 100 ppb, 300 ppb and 2000 ppb was investigated. The results indicated weight gain increased with the dissolved oxygen increasing. The herpes-shaped oxides were formed on the sample surface. The oxide layer was a typical dual-layered structure with a Fe-rich outer layer and a Fe-Cr-Ni-rich inner layer. The influences of the dissolved oxygen concentration and grain size on oxidation behavior were discussed finally.

Abstract: Abstract: Based on ammonia recycled percolation (ARP) and combined with the advantage of ammonia fiber explosion (AFEX), a set of reflowed aqua ammonia explosion pretreatment (RAAEP) equipment was developed. According to the previous orthogonal experiment experimental results, the optimal pretreatment conditions were at 90°C, 9 min retention time, water to dry corn stover loading of 0.8:1(w/w), and aqua ammonia flow rate is 1.5L/min. The cellulose content of the pretreated corn stover was 50.46 % and the glucan and xylan enzymatic digestibility was 86.45 % and 95.77% respectively. The reflowed aqua ammonia not only caused fiber swelling and an efficient delignification (up to 62.5%) of biomass, but also altered the cellulose crystalline structure. The SEM picture and FTIR spectra confirmed swelling and significant delignification effects of the RAAEP process. The X-ray crystallography data indicated that the rigid structure of corn stover was disrupted with more crystallization fiber being exposed after the pretreatment process, but the crystallinity increased due to the removal of amorphous materials (lignin and hemicelluloses).

Abstract: Scaling-translation symmetry is combined by translation symmetry and scaling symmetry, it widely exists in mechanical systems, and plays an important role in realizing the technical, economic and social performances of mechanical products. Based on the concept system of translation symmetry, and according to the research on a lot of instances, the concept system of scaling-translation symmetry classified by the directivity and alternations of symmetry components, the dimensionality and closed circle of symmetry benchmark, and the variable type of scaling was established. The concept system can completely contain all kinds of existence of scaling-rotation symmetry in mechanical systems, and can provide a theoretical basis for the further research on the application of scaling-translation symmetry in mechanical systems.