Applied Mechanics and Materials Vols. 66-68

Abstract: The finite element method (FEM) is widely adopted in the geotechnical engineering, but there exist some problems in practical applications, such as the lack of unified standard to determine parameters and the limitation of the calculation method. This article determines the reasonable value of Poisson ratio, by comparing different Poisson ratios selected in the strength reduction of FEM calculations, and improves the gravity increase method in order to enhance its accuracy in the gentle slope stability analyses.

Abstract: This dissertation adopts Data Envelopment Analysis method, in accordance with principles of comprehensiveness, concise, relevance and relativity as well as decision package requirements on quality and quantity, it selects four input indexes as woodland area, stuff, technical stuff proportion and fund; two output indexes as live stumpage and output value of state-owned forest farm, and takes use of DEAP2.1 software based on input-oriented BCC model to make an efficiency evaluation of 11 state-owned forest farms which participate in forest tenure reform and 19 which does not. The result shows no matter it's technical efficiency, scale efficiency or pure technical efficiency, forest farms which carries out reform are more efficient that those which does not.

Abstract: In the present work PID control and the fuzzy logic based intelligent control is used to control the rectilinear plant vibrations. PID controller in real time mode is implemented on FPGA. For implementation of fuzzy logic based intelligent controller the FPGA is used as real time data acquisition (DAQ) platform and the fuzzy controller is implemented on the host PC. The sole reason for using FPGA as data acquisition platform was that the LabVIEW FPGA software module is not supporting the complex mathematics required for the fuzzy logic control and also the rectilinear plant interface with the traditional DAQ was not available. The comparative study of performance of intelligent controllers like fuzzy PD and fuzzy PI+ fuzzy PD is done with the conventional controllers on the basis of above mentioned performance indices. The result of the fuzzy PI + fuzzy PD controller is found to be the best among all.

Abstract: In this study, SPICE program is applied to design micro fluidic circuits based on the analogical relationship with MOSFET models for the first time. A SPICE model of pneumatic-FET is established to express the behavior of them in micro fluidic circuits. Construction of pneumatic-FET model, its optimization, and effectiveness in circuit design and comparison are discussed in the later sections.

Abstract: This paper presents a novel pressure sensor based on IL electrofluidic circuit. The simple configuration makes the device capable of being seamlessly integrated to wide varieties of PDMS microfluidic devices. The experimental results demonstrate that IL-filled microfluidic channels can be utilized as electrical resistors to construct functional circuits, and an electrofluidic Wheatstone bridge circuit has been designed to construct the pressure sensor. In the pressure sensor performance characterization, the calibration results show that the gate voltage is linear proportional to the applied pressure with sensitivity of 8.45 mV/psi and the pressure as small as 2.5 psi can be easily detected.

Abstract: Fatigue deformation behavior of the commercially pure iron containing micro-voids at grain boundaries (GBs) were investigated under total strain amplitude control, and fatigue fractures were quantitatively characterized by fractal analyses. The cyclic response curves of the CP iron show an initial softening stage within early several cycles followed by a continuous cyclic hardening. No stress saturation phenomenon was found. Pre-existence of micro-voids at GBs spurs intergranular cracking to become a common damage mode besides transgranular cracking along slip bands. Quantitative analyses of fracture surface demonstrate that the value of fractal dimension D of the scanning profile in the crack growth zone is the largest as compared to those in the crack source zone and final rapid fracture area, almost regardless of the applied strain amplitude. This phenomenon was discussed in terms of the tortuosity of crack propagation path.

Abstract: In this paper we proposed a new dynamic scheduling algorithm for power scheduling problem. The algorithm is based on game theory and reinforcement learning approach. We compared the performance of our algorithm with that of online bin packing and MAB algorithm. We observed that our algorithm performs better than online bin packing when there is a variation in the deadlines. This is because our algorithm schedules the requests on the basis of their actions and the probability of missing the deadline and online bin packing algorithm schedules requests based on the sequence of requests as they arrive. We observed that our approach is more useful, when scheduling requests repeat themselves for long duration.

Abstract: Matching feature points is an important step in image registration. For high- dimensional feature vector, the process of matching is very time-consuming, especially matching the vast amount of points. In the premise of ensuring the registration, filtering the candidate vectors to reduce the number of feature vectors, can effectively reduce the time matching the vectors. This paper presents a matching algorithm based on filtering the feature points on their characteristics of the corner feature. The matching method can effectively improve the matching speed, and can guarantee registration accuracy as well.

Abstract: The plastic deformation behavior of the and [014] Fe-35wt.%Cr alloy single crystals containing fine Cr-rich precipitates were investigated under uniaxial compression. The compressive flow behavior is slightly sensitive to the crystallographic orientation. These two oriented crystals exhibit a clear yield plateau in their compressive stress-strain curves, but the yield plateau of the [014] crystal is somewhat shorter than that of the crystal. As the compressive strain is lager than a certain critical value, e.g., ~13% and ~18% for the [014] and crystals, respectively, the work hardening rate for both two orientations decreases obviously, but the decrease in work hardening rate is more remarkable for the [014] crystal rather than the crystal. These phenomena are discussed to be all related to the interactions between moving dislocations and fine Cr-rich precipitates, and the interaction intensity depends strongly on the orientation. Careful observations of slip deformation characteristics and dislocation structures well provide supports for the explanations to the macroscopic compressive plastic flow behavior.

Abstract: In order to carry out reaction smoothly, a measure and control system of an onboard micro-channel reactor for hydrogen production via methanol steam reforming is developed. A subsystem of temperature control is designed to measure and control the temperatures of reactor and evaporator. Flow control subsystem, including liquid flow control of reactant and mass flow control of reducing gas, is also developed. Virtual instrument technology and graphical programming language LabVIEW are applied to integrate all the control functions in a single program, which makes it convenient for operation and further development. The experimental results validate that the reaction can be carried out successfully under the control of this measure and control system.