Advanced Materials Research Vols. 403-408

Abstract: The objective of this experiment is to study the effect of taper angle of the optical fiber microprobe in power collection. Optical fiber microprobes with taper angle from 10° to 23° were fabricated using the automatic fusion splicer by applying one-sided pulling and electric arc heating technique. It was found that the maximum power detected by a small taper angle probe was only -34.22dBm. The highest optical power collected by the optical fiber microprobe in this study was -25.01dBm with taper angle of 22.9°. Large taper angle probe receives more light at the tip which increases the sensitivity of the probe.

Abstract: Quantum-dot cellular automata (QCA) is an emerging nanotechnology that provides faster speed, smaller size and lower power consumption compared to the current transistor-based technology. Adder/ subtractor is a useful component for the design of many computation systems and functional circuits. This paper proposes a practical XOR design in QCA. Then the first adder/subtractor circuit in QCA is designed and simulated using the proposed XOR design. Results of simulation were carried out using QCADesigner.

Abstract: It is necessary to detect the aggregation dynamics and aggregation process of industry cluster for there are still some problems in the development of industrial cluster. The existing theories are less attention to the impacts of the social network of enterprises and their interactions on the industrial aggregation. We proposed a social network interaction model and research on the industrial aggregation process from the aspect of economic sociology. The impacts of signal effect, network effect and crowding effect on the dynamic micro-macro process of industrial aggregation are discussed and two possible phase transition and its causes in industrial aggregation process are explored. The simulation outcomes are good explanations for industrial aggregation process and made some useful implications for policy-making.

Abstract: Shading devices for buildings are able to resist thermal radiation and decrease air conditioning load, this study used shading devices for buildings as an example, and conducted a patent search in the United States Patent and Trademarks Office (USPTO). This study adopted bibliometric and social network analysis methods to portray the relation between citing and cited patents, to discover the patent main path, grasping the correlation between patent technologies and the overall industrial development. The purpose of this study was to construct patent citation networks, to trace the developmental context of key technologies and their diffusion. The results suggest that automated shading devices are the focus of current technological developments, contributing to rapid advancements and helping developers save time and costs.

Abstract: This paper reports on the simulation and characterization of a microelectromechanical system (MEMS) micromirror fabricated with PolyMUMPs. The overall diameter of the hexagonal micrimirror, including mirror plate and 3 supporting cantilevers fixed around, is 450um. A 3D model is built in finite element method (FEM) with COMSOL. Simulations of the elevated height of mirror plate, pull-in voltage and eigenfrequency of the micromirror are carried out. The static and dynamic performances of the fabricated micromirror are characterized by Veeco Optical Profiler and Polytek MEMS System Analyzer. The comparison between measurement and simulation exhibits good concordance. Surface topography measurement shows the elevated height and stress-induced concave deformation of mirror plate almost the same scale as demonstrated in FEM simulation. The Pull-In voltages are measured to be around 32V in current-voltage curve which is almost the same as in FEM simulation with one electrode biased. The fundamental resonant frequency is measured to be 4.3k Hz in torsional motion and 4.9k Hz in piston motion.

Abstract: Pipelines are one of the most important and efficient ways for transporting energy like water, gas, oil and etc. between different places all across the world. As these pipelines are located in different conditions and situations, they are all sensitive to a wide variety of damages like vibration, so monitoring their structural behavior is an essential task. Monitoring pipeline vibration caused by cavitation through an orifice by a piezoelectric sensor is presented in this paper.

Abstract: BP neural network model of tire and three degrees of freedom dynamic model of Multi-Axle vehicle were built. According to Zero side slip angle control theory, with the use of MATLAB software, comparative analysis of the step response of the vehicle side slip angle, yaw angle velocity and rolling angle in the driving vehicle with linear and nonlinear tires was done. The results show thatMulti-Axle vehicle with nonlinear tires has obvious affect between side slip angle and yaw angle velocity of the vehicle body. Relative to Multi-Axle vehicle with linear tires, the overshoot of step response increases greatly, and the Steady-State value does not equal to zero; but rolling angle of the vehicle with nonlinear tires has less affected.

Abstract: The paper revisits the approach of distributed timed automata in order to improve and optimize the methodology used in order to increase the availability of a safety critical system and implements using embedded real time task scheduler. A double wheel counter or digital axle counter system, a typical safety critical system that is used in solid state based railway signaling systems, is considered for achieving higher availability under certain failures. The improvement in the software architecture is influenced by the theory of task scheduler of real time operating system.

Abstract: In this paper, an unsupervised color image segmentation scheme has been proposed for preserving strong and weak edges as well. A Constrained Compound Markov Random Field (MRF) has been proposed as the a priori model for the color labels. We have used Ohta (I1, I2, I3) color model and a controlled correlation of the color space has been accomplished by the proposed compound MRF model. The Constrained Compound MRF (CCMRF) is found to possess the unifying property of modeling scenes as well as color textures. In unsupervised scheme, the associated model parameters and the image labels are estimated recursively. The model parameters are the Maximum Conditional Pseudo Likelihood (MCPL) estimates and the labels are the Maximum a Posteriori (MAP) estimates. The performance of the proposed scheme has been compared with that of Yu’s method and has been found to exhibit improved performance in the context of misclassification error.

Abstract: The wireless adhoc network is comprised of nodes (it can be static or mobile) with wireless radio interface. Each host is equipped with a CSMA/CA (carrier sense multiple access with collision avoidance) transceiver. These nodes are connected among themselves without central infrastructure and are free to move around. It is a multihop process because of the limited transmission range of energy constrained wireless nodes. This creates the scenario of multihop, where the packets originated from the source host are relayed through several intermediate hosts before reaching the destination. Routing is the process of finding a path from a source to destination among randomly distributed routers in dynamic network. In this paper table driven routing protocol STAR and on demand routing protocols DSR, DYMO based on IEEE 802.11 are surveyed and characteristic summary of these routing protocols is presented. Their performance is also analyzed on performance metrics throughput, jitter, data delivery ratio and end-to-end delay by varying nodes mobility with CBR data traffic load using QualNet 5.0.2 network simulator.