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Zhang J.,Northwest University, China | Qiao X.,Northwest University, China | Qiao X.,Xian Shi you University | Feng Z.,Northwest University, China | And 3 more authors.
2011 Symposium on Photonics and Optoelectronics, SOPO 2011

A compact metal bellows-based fiber Bragg grating accelerometer is proposed in this paper. The acceleration can be measured by monitoring the center wavelength shift of FBG, which we show is proportional to accelerometer. The experimental results indicate that the FBG accelerometer with a high sensitivity of 567.2pm/g shows a good linear response of the wavelength shifts versus applied acceleration. In addition, it provides a broad flat response over a vibration frequency ranging from 5 to 120Hz. The upper vibration frequency limit of measure is determined by mechanical resonance, and can be tuned by varying the weight of inertial mass. A series of table-shaking tests were conducted and showed good performance of a prototype FBG accelerometer. © 2011 IEEE. Source

Hao H.-N.,Xian Shi you University
Proceedings - 2010 6th International Conference on Natural Computation, ICNC 2010

For short-term forecasting of stock price, this paper proposes a method of analyzing and forecasting the closing price of a stock based on the genetic-BP algorithm. Results show that, within the range of allowable error, the obtained data from the present model can well forecast the short-term trend of a stock price. Though stock market is a very complex nonlinear system, it has the better foreground to predict stock price using neural network. The studies in this paper also prove that genetic- neural algorithm can improve the speed and reliability of the foresting method. © 2010 IEEE. Source

Zhang Y.-S.,Xian Shi you University | Qiao X.-G.,Xian Shi you University | Qiao X.-G.,Northwest University, China | Shao M.,Xian Shi you University | And 3 more authors.
Guangzi Xuebao/Acta Photonica Sinica

An in-fiber Mach-Zehnder interferometer humidity sensor based on waist-enlarged fiber tapers cascade structure was proposed and demonstrated. The sensor head is formed by a taper-single-mode-taper-single-mode-taper structure through arc fusion splicing. The change of the humidity and temperature will make the optical path difference changed of the sensor core mode and cladding modes, causing interference spectral change. Through monitoring the spectra variation can determine the ambient physical quantities. The experimental results show that the humidity sensitivity of the sensor is -0.065 dB/%RH with a linearity of 0.997 in the humidity range of 35~95%RH; the temperature sensitivity of the sensor is 69.4 pm/℃ with a linearity of 0.998 in the temperature range of 30~80℃. This sensor can avoid the cross-sensitivity to humidity and temperature, make it a good candidate for high accuracy humidity and temperature applications. ©, 2015, Chinese Optical Society. All right reserved. Source

Yuan Z.,Xian Shi you University | Li W.-H.,Northwest University, China | Zhu J.,Petrochina | Guo Y.-Q.,Xian Shi you University
Geological Bulletin of China

With logging, seismic, core and other geological data, the paleogeomorphology was rebuilt according to the impression method and comprehensive geological method. The results reveal various paleogeomorphic patterns, such as high land, valley, brae, mound and river terrace. Based on the relationships between the paleomorphology and the formation of Yan'an oil reservoir, the authors inferred that reservoirs are mainly distributed in the brae near high land and other relatively high zones. Favorable conditions for petroleum accumulation included the upward migration pathway of hydrocarbon from source rock of Yanchang Formation via the incised valley, the type and distribution of reservoirs and sand bodies were controlled by the brae, and the relatively high zones of later structural traps were formed by the "impression" of layers. Source

Liu Y.S.,Xian Shi you University | Ning Y.P.,Xian Shi you University
Applied Mechanics and Materials

In this paper, the instrument is designed by basing on principle of the measurement method of straightness error measurement of deep hole, the design technologies of A/D converters, automatic control and computer are used. The instrument can automatically acquire data, the process of acquire data is convenient, fast, safe and the data is reliable. © (2012) Trans Tech Publications, Switzerland. Source

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