Applied Mechanics and Materials Vols. 672-674

Abstract: This paper produced a data caching system framework based on two-layer Chord. Caching is shared by users in domain and hot accessing information is shared by inter-domain users. It effectively reduces the caching system’s overhead. We also introduced cache replacement algorithm based on the user community, especially the user’s influence in the community and the information flow dynamics. The result of simulation and experiment of test-bed environment shows the caching scheme based on user community outperforms most existing distributed caching schemes.

Abstract: In this thesis,surface integrals and the relationship between characteristics of the second class and second class double integral surface integrals, analyzes the application of the law of symmetry integral calculation, even if the integration region derived symmetric integrand is an odd function integral value characteristic is not necessarily zero. And pointed out that the feasibility of the method is definitely second class surface integrals.

Abstract: This paper presents a GPRS thermal printer which is based on Internet of Things. The main control chip of the printer initializes the GPRS module, connects the restaurant reservation website servers and cell phones, and accepts orders from Internet and phone messages. Then the printer prints two same receipts. Meanwhile the information on the reservation is saved in SD card. After confirmation of orders, confirmation information would be sent back to relevant network ports or phones so that they can reaffirm each other. A GPRS wireless thermal printer which is based on Internet of Things can print the customers’ order timely and remind staff to handle them in time. It can be widely used in restaurant reservation website and other relevant service.

Abstract: Acoustic pyrometry is a comparatively advanced method of temperature measurement developed in recent years, which possesses the essential characteristics of traditional temperature measurement approach. Considering the interferences, like strong background noise, reverberation and so on, in boiler furnace, the LMS (least mean square) adaptive filter algorithm should be improved to meet certain environment above. In order to make the LMS algorithm have the characteristic of fast convergence and small steady state error, an improved, power-normalized and variable step-size discrete cosine transform LMS algorithm is proposed, which combines the power-normalized discrete cosine transform LMS algorithm with the variable step size LMS algorithm that uses the sliding forgetting-weighted window. The time delay estimation simulation in the strong-noise environment verifies the improved DCT-MVSS LMS algorithm can achieve good performance.

Abstract: Wavelet analysis technique is proposed in the filter processing to remove the noise from random drift signal of fiber optic gyroscope (FOG). Based on the component elements of random drift signal of FOG, mathematical model of random drift signal of FOG is built. According to the shortcomings of hard threshold and soft threshold, threshold function of forced denoising is used in signal filtering. It is shown from simulation and statistic analysis that the wavelet analysis technique is an effective method to eliminate noise from random drift signal of FOG, and that selection of wavelet base and decomposition scale also has an impact on filtering effect of wavelet analysis.

Abstract: This paper presents a new cross-layer QoS routing algorithm for wireless sensor networks. Basing on the principle of cross-layer design, the algorithm adopts delay, nodes’ load and link quality as QoS metrics. The QoS routing metrics are regarded as heuristics correction factors in ant colony algorithm (ACA). The ants are divided into a number of different populations. Through the interaction of pheromone between multi populations, the routing algorithm searches for the feasible paths in parallel and updates the pheromone in time. To overcome the slow convergence of ant colony algorithm, membership cloud model (MCL) is used to control the randomness of the ants. The simulation results demonstrate that the routing algorithm can guarantee the real time, reliability and robustness of wireless sensor networks. It can also achieve the network load balancing.

Abstract: This paper presents the interference impact of Ultra Wide-Band (UWB) sensor using frequency of 3.5 GHz on 3G mobile system in Korea. The Minimum Coupling Loss (MCL) method and Spectrum Engineering Advanced Monte Carlo Analysis Tool (SEAMCAT) were used to evaluate the interference impacts of UWB sensor on 3G mobile system. The minimum allowable distance between UWB interferer and the victim receiver is required 0.09 m in indoor environment; in the case of multiple UWB interferers in outdoor environment, the maximum allowable UWB transmitting Power Spectral Density (PSD) should be-93.1 dBm/MHz below to guarantee co-existence with 3G mobile system.

Abstract: This paper investigates the application of systematic cluster, one of the cluster analysis methods, in the IED switch online condition monitoring. So far, problems still exsit in the IED switch online condition monitoring based on the control system of smart substation. In order to figure out a relatively stable online model and make classification from the online information of IED switch, this paper firstly fliters and preprocesses the online condition information of IED switch, and uses data matrix to describe the online condition of IED switch. Based on this, the paper inroduces a special dissimilarity degree formula to transfer the data matrix into dissimilarity degree matrix, and conducts analysis with clustering pedigree chart out of systematic cluster algorithm. Finally, the paper verifies the feasibility of systematic cluster in the IED switch online condition monitoring.

Abstract: In order to design a compact star simulator based on multiple LEDs, optical fibers, an integral sphere and tiny collimated optical systems are employed in the system. Firstly the system configuration block diagram of the star simulator is given in this paper. Then the luminous flux calculation of LED is calculated based on the optical system. Finally the principle of PWM control of LED is illustrated. The analysis shows that the simulated precision of star magnitude can achieve ±0.1^m.

Abstract: In this paper, the communication between PLC and PID temperature controller are researched. The asynchronous communication protocol of E909 is used to protect the data that transformed among the bus. The process of speaking, reading and writing of PV and SV value as well as the PID temperature controller communication combine no protocol communications is designed in this paper. At last the models are realized by programming. Experiments show the project we proposed can finish the data transformation in real-time without damage and lost.