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Search Results: 1 - 10 of 23304 matches for " Shaopeng He "
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Development of Deep-Sea Resonant Sandwich Linear Ultrasonic Motor  [PDF]
Shaopeng He, Shengjun Shi, Weishan Chen
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.61028
Abstract:
A deep-sea resonant sandwich linear ultrasonic motor is proposed and designed. We determine the parameter of its structure by finite-element analysis. The piezoelectric actuator adopts compound vibration mode of fifth order bending vibration and second order longitudinal. The mode degeneracy of that is completed. We manufacture the prototype to measure the performance of it. We measure its vibration mode and resonant frequency. The velocity of prototype can reach 264.5 mm/s while the water pressure is 8 MPa and the voltage signal with frequency of 30.30 kHz and voltage amplitude of 150 V.
Electric-field-induced stress relaxation in alpha-phase poly(vinylidene fluoride) films
Xiangtong He,Shaopeng Pei,Robert E. Baier,John Y. Fu
Physics , 2013, DOI: 10.1016/j.matlet.2014.05.109
Abstract: The relationship between elastic fatigue and electrical cyclic loading in alpha-phase poly(vinylidene fluoride) films has been investigated. Our experimental studies have shown that the electric-field-induced fatigue behavior can be described by a stress relaxation, which belongs to the Kohlrausch function group, and the corresponding exponent is a modified two-parameter Weibull distribution function.
Soil Respiration in Tibetan Alpine Grasslands: Belowground Biomass and Soil Moisture, but Not Soil Temperature, Best Explain the Large-Scale Patterns
Yan Geng, Yonghui Wang, Kuo Yang, Shaopeng Wang, Hui Zeng, Frank Baumann, Peter Kuehn, Thomas Scholten, Jin-Sheng He
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0034968
Abstract: The Tibetan Plateau is an essential area to study the potential feedback effects of soils to climate change due to the rapid rise in its air temperature in the past several decades and the large amounts of soil organic carbon (SOC) stocks, particularly in the permafrost. Yet it is one of the most under-investigated regions in soil respiration (Rs) studies. Here, Rs rates were measured at 42 sites in alpine grasslands (including alpine steppes and meadows) along a transect across the Tibetan Plateau during the peak growing season of 2006 and 2007 in order to test whether: (1) belowground biomass (BGB) is most closely related to spatial variation in Rs due to high root biomass density, and (2) soil temperature significantly influences spatial pattern of Rs owing to metabolic limitation from the low temperature in cold, high-altitude ecosystems. The average daily mean Rs of the alpine grasslands at peak growing season was 3.92 μmol CO2 m?2 s?1, ranging from 0.39 to 12.88 μmol CO2 m?2 s?1, with average daily mean Rs of 2.01 and 5.49 μmol CO2 m?2 s?1 for steppes and meadows, respectively. By regression tree analysis, BGB, aboveground biomass (AGB), SOC, soil moisture (SM), and vegetation type were selected out of 15 variables examined, as the factors influencing large-scale variation in Rs. With a structural equation modelling approach, we found only BGB and SM had direct effects on Rs, while other factors indirectly affecting Rs through BGB or SM. Most (80%) of the variation in Rs could be attributed to the difference in BGB among sites. BGB and SM together accounted for the majority (82%) of spatial patterns of Rs. Our results only support the first hypothesis, suggesting that models incorporating BGB and SM can improve Rs estimation at regional scale.
The Pastry Algorithm Based on DHT
Jihong Song,Shaopeng Wang
Computer and Information Science , 2009, DOI: 10.5539/cis.v2n4p153
Abstract: In the P2P network, how to quickly and accurately positioning of resources is a key measure of the performance. Nowadays, distributed P2P system generally adopts DHT search method, DHT-based P2P network search algorithm of P2P is a hot topic. The paper introduces the background and current research status of the DHT. Then focused on the Pastry algorithm, Finally Pastry algorithm was analyzed and some disadvantage about it was discussed.
Numerical studies of an eccentric tube-in-tube helically coiled heat exchanger for IHEP-ADS helium purification system
Jianqin Zhang,Shaopeng Li
Physics , 2014,
Abstract: The tube-in-tube helically coiled (TTHC) heat exchanger is preferred in the purifier of IHEP-ADS helium purification system. The position of an internal tube is usually eccentric in a TTHC heat exchanger in practice, while most TTHC heat exchangers in the literature studied are concentric. In this paper, TTHC heat exchangers with different eccentricity ratios are numerically studied for turbulent flow and heat transfer characteristics under different flow rates. The fluid considered is helium at the pressure of 20Mpa, with temperature dependent thermo-physical properties for the inner tube and the annulus. The inner Nusselt number between the concentric and eccentric TTHC heat exchangers are compared, so is the annulus Nusselt number. The results show that with the eccentricity increasing, the annulus Nusselt number increases substantially. According to the numerical data, new empirical correlations of Nusselt number as a function of Reynolds number and eccentricity for the inner tube and the annulus are presented in this paper. The TTHC heat exchanger of the purifier is designed under the given conditions.
A Short Image Series Based Scheme for Time Series Digital Image Correlation
Xian Wang,Shaopeng Ma
Computer Science , 2014,
Abstract: A new scheme for digital image correlation, i.e., short time series DIC (STS-DIC) is proposed. Instead of processing the original deformed speckle images individually, STS-DIC combines several adjacent deformed speckle images from a short time series and then processes the averaged image, for which deformation continuity over time is introduced. The deformation of several adjacent images is assumed to be linear in time and a new spatial-temporal displacement representation method with eight unknowns is presented based on the subset-based representation method. Then, the model of STS-DIC is created and a solving scheme is developed based on the Newton-Raphson iteration. The proposed method is verified for numerical and experimental cases. The results show that the proposed STS-DIC greatly improves the accuracy of traditional DIC, both under simple and complicated deformation conditions, while retaining acceptable actual computational cost.
Multi-Sensor Ensemble Classifier for Activity Recognition  [PDF]
Lingfei Mo, Shaopeng Liu, Robert X. Gao, Patty S. Freedson
Journal of Software Engineering and Applications (JSEA) , 2012, DOI: 10.4236/jsea.2012.512B022
Abstract: This paper presents a multi-sensor ensemble classifier (MSEC) for physical activity (PA) pattern recognition of human subjects. The MSEC, developed for a wearable multi-sensor integrate measurement system (IMS),combines multiple classifiers based on different sensor feature sets to improve the accuracy of PA type identification.Experimental evaluation of 56 subjects has shown that the MSECis more effectivein assessing activities of varying intensitiesthan the traditional homogeneous classifiers. It is able to correctly recognize 6 PA types with an accuracy of 93.50%, which is 7% higher than the non-ensemble support vector machine method. Furthermore, the MSECis effective in reducing the subject-to-subject variabilityin activity recognition.
Component Carrier Selection and Beamforming on Carrier Aggregated Channels in Heterogeneous Networks  [PDF]
Changyin Sun, Hongfeng Qing, Shaopeng Wang, Guangyue Lu
Communications and Network (CN) , 2013, DOI: 10.4236/cn.2013.53B2040
Abstract: In this paper, component carrier selection and beamforming on carrier aggregated channels in Heterogeneous Networks are proposed. The scheme jointly selects the component carrier and precoding (i.e. beamforming) vectors with the cooperation of the other cells to deal with the interference between Macro cell and Pico cell. The component carrier selection and beamforming is achieved by optimizing the multi-cell downlink throughput. This optimization results in shutting down a subset of the component carrier in order to allow for a perfect interference removal at the receive side in the dense low power node deployment scenario. Additionally, algorithm based on Branch and Bound Method is used to reduce the search complexity of the algorithm. Simulation results show that the proposed scheme can achieve high cell-average and cell-edge throughput for the Pico cell in the Heterogeneous Networks.
Application of Structural Breakpoint Test to the Correlation Analysis between Crude Oil Price and U.S. Weekly Leading Index  [PDF]
Yi Xiong, Shaopeng Sun, Zicheng Wang, Ke Wang, Li Liu
Open Journal of Business and Management (OJBM) , 2016, DOI: 10.4236/ojbm.2016.42034
Abstract: The paper examines the relationship between crude oil price and U.S. weekly leading index. The relationship between these two variables was unstable in long-run, so we explored the structural breakpoints from January 1995 to August 2015 by Bai-Perron breakpoint test. The results show that the causal relationships between two variables in different periods are different. We distinguish different periods from the breakpoints, and explain the main reasons for change of the casual relationships. Through this theory, the market can have a better prediction for the crude oil price base on weekly leading index.
Research and Practice on the Profile Control Characteristics of Emulsions in Bohai Oil Field  [PDF]
Dongdong Yang, Meinan Wang, Feifei Miao, Shaopeng Wang, Junting Zhang
Journal of Geoscience and Environment Protection (GEP) , 2018, DOI: 10.4236/gep.2018.68005
Abstract: In order to study the profile control characteristics of emulsions in porous medium, the heterogeneous experimental model was established, by which the experimental scheme was designed with different permeabilities, matching degree of particle size and concentration of emulsions. Based on experimental results of physical simulation, the concept of distributing rate and changing coefficient was introduced to quantitatively evaluate the profile control characteristics of emulsions. The results of the study show that, as the permeability ratio and emulsion concentration increase, the profile control characteristics of emulsions will enhance. The profile control characteristics of emulsions will be the best. The profile control scheme with emulsions was implemented in Bohai X oil field, The research results can be used for reference to design the profile control scheme in Bohai heterogeneous reservoir.
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