oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 6 )

2019 ( 32 )

2018 ( 193 )

2017 ( 176 )

Custom range...

Search Results: 1 - 10 of 10338 matches for " Yonggang Qian "
All listed articles are free for downloading (OA Articles)
Page 1 /10338
Display every page Item
An Impedance-Permeability Self-Resonance of Inductance Coil with Metamaterials
Qiang Yu;Qian Zhao;Yonggang Meng
PIER , 2013, DOI: 10.2528/PIER12122408
Abstract: An impedance-permeability (Z-) resonance phenomenon is firstly founded and numerically demonstrated when electromagnetic metamaterials with negative permeability are firstly introduced into inductance coil. Numerical results reveal that the impedance-permeability relationship exhibits an extraordinary self-resonant phenomenon at a certain negative value of relative permeability, which is related to the dimensions of the core but nearly independent to the coil size. Such a mechanism is proposed to increase the sensitivity of eddy current (EC) sensors up to about 270 times, offering a new method to greatly improve the sensitivity of EC sensors and the spatial resolution with micrometer scale.
The Characteristics of Breast Cancer Mortality in Inner Mongolia between 2008 and 2010  [PDF]
Yueling Hu, Yun Li, Wenrui Wang, Yonggang Qian, Chunxia Hui, Kepeng Xin, Shiqi Wang, Juan Sun
Open Journal of Epidemiology (OJEpi) , 2014, DOI: 10.4236/ojepi.2014.43019
Abstract:

Background: The aim of this study was to explore the characteristics of breast cancer mortality in Inner Mongolia, and to provide evidence for the prevention of female breast cancer. Methods: Using data from the Death Registry System from 2008 to 2010. We classified female cancer deaths according to the International Classification of Disease-10th Revision. The mortality of different age groups and the potential years of life lost were calculated for female breast cancer in Inner Mongolia. Results: Breast cancer mortality for Inner Mongolian women was higher in older age groups. The potential years of life lost were also much higher in younger groups than in older groups. Marital status, education level and occupation may contribute to this increase in breast cancer mortality in younger groups. Conclusion: Preventive policies should be implemented to de- velop strategies aimed at reducing the breast cancer mortality, especially with regard to younger age groups in Inner Mongolia.

Equivalent Martingale Measure in Asian Geometric Average Option Pricing  [PDF]
Yonggang Zhu
Journal of Mathematical Finance (JMF) , 2014, DOI: 10.4236/jmf.2014.44027
Abstract:
The general situation of the Black-Scholes Option Pricing Model was discussed under the assumption of the arbitrage-free market, and the pricing of Asian geometric average options with fixed strike price was analyzed at any valid time. Consequently, the price formula of the Asian geometric average options was drawn using the equivalent martingale measure and the significance of the study was also indicated.
A Contextual Fire Detection Algorithm for Simulated HJ-1B Imagery
Yonggang Qian,Guangjian Yan,Sibo Duan,Xiangsheng Kong
Sensors , 2009, DOI: 10.3390/s90200961
Abstract: The HJ-1B satellite, which was launched on September 6, 2008, is one of the small ones placed in the constellation for disaster prediction and monitoring. HJ-1B imagery was simulated in this paper, which contains fires of various sizes and temperatures in a wide range of terrestrial biomes and climates, including RED, NIR, MIR and TIR channels. Based on the MODIS version 4 contextual algorithm and the characteristics of HJ-1B sensor, a contextual fire detection algorithm was proposed and tested using simulated HJ-1B data. It was evaluated by the probability of fire detection and false alarm as functions of fire temperature and fire area. Results indicate that when the simulated fire area is larger than 45 m2 and the simulated fire temperature is larger than 800 K, the algorithm has a higher probability of detection. But if the simulated fire area is smaller than 10 m2, only when the simulated fire temperature is larger than 900 K, may the fire be detected. For fire areas about 100 m2, the proposed algorithm has a higher detection probability than that of the MODIS product. Finally, the omission and commission error were evaluated which are important factors to affect the performance of this algorithm. It has been demonstrated that HJ-1B satellite data are much sensitive to smaller and cooler fires than MODIS or AVHRR data and the improved capabilities of HJ-1B data will offer a fine opportunity for the fire detection.
Generalized Cramer-Rao Bound for Joint Estimation of Target Position and Velocity for Active and Passive Radar Networks
Qian He,Jianbin Hu,Rick S. Blum,Yonggang Wu
Statistics , 2015,
Abstract: In this paper, we derive the Cramer-Rao bound (CRB) for joint target position and velocity estimation using an active or passive distributed radar network under more general, and practically occurring, conditions than assumed in previous work. In particular, the presented results allow nonorthogonal signals, spatially dependent Gaussian reflection coefficients, and spatially dependent Gaussian clutter-plus-noise. These bounds allow designers to compare the performance of their developed approaches, which are deemed to be of acceptable complexity, to the best achievable performance. If their developed approaches lead to performance close to the bounds, these developed approaches can be deemed "good enough". A particular recent study where algorithms have been developed for a practical radar application which must involve nonorthogonal signals, for which the best performance is unknown, is a great example. The presented results in our paper do not make any assumptions about the approximate location of the target being known from previous target detection signal processing. In addition, for situations in which we do not know some parameters accurately, we also derive the mismatched CRB. Numerical investigations of the mean squared error of the maximum likelihood estimation are employed to support the validity of the CRBs. In order to demonstrate the utility of the provided results to a topic of great current interest, the numerical results focus on a passive radar system using the Global System for Mobile communication (GSM) cellar system.
Comparison of Climate and Environment Change of the Last Interglacial Period and Holocene in Beijing Area, China  [PDF]
Yonggang Ge, Mingjian Wei
International Journal of Geosciences (IJG) , 2014, DOI: 10.4236/ijg.2014.58075
Abstract:

Research on climate changes between the last interglacial period and Holocene renders a speculation on the tendency of present climate. Fully understanding the nature of the changes will play a significant role in a better understanding of global climate change. This work discussed the climate change of the last interglacial period and Holocene in Beijing area to discover the mechanism of local palaeo-climate change. The palaeo-vegetation of the last interglacial period in Xishan Mountain of Beijing was reconstructed by pollen analysis and thermo-luminescence dating to represent the change of palaeo-climate and palaeo-environment. Palaeo-vegetation indicators demonstrated that the climate change of the last interglacial period included 6 stages and was homologous to that reflected by the records from deep sea depositions and polar ice cores, respectively corresponding to Marine Isotope Stage (MIS) 5e, 5d, 5c, 5b, 5a and the interim from MIS5 to MIS4 from the early to the late. Millennial climate abrupt events occurred in MIS 5e, which had an agreement with the records of GRIP. In addition, a climate warming event appeared in the interim from MIS5 to MIS4 and it also was found in other regions of the world. Compared with the vegetation and environment indicators of Holocene in Beijing area, it was found that the vegetation, climate and environment of the last glacial period were better than those of Holocene. The climate abrupt events not only appeared in the last interglacial period and MIS 5e, but also occurred in Holocene, whose mechanism and pattern were analogical. After analyzing the records of millennial climate abrupt change events from this work, Ice Cores and others, it was concluded that climate was instability in the interglacial period.


Characteristics and Causes of Disastrous Debris Flows on July 4, 2013, in Shimian County, Sichuan, China  [PDF]
Yonggang Ge, Fenghuan Su
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.74039
Abstract: Debris flow is an abrupt phenomenon of earth surface movement and typical disaster in mountainous areas with steep terrace, quantity of loose soil and abundant surface runoff. Intense rainfall and rainstorm easily triggered debris flows and generated huge losses. The disastrous debris flows, on July 4, 2013 at the gullies of Hou, Heilinzi and Xiongjia in Shimian County, Sichuan Province, resulted in 18 casualties and endangering Shimian city with a population of 50,000. These debris flows were characterized by low viscosity with only 0.9% - 1.4% clay soil of less than 0.05mm, density of 1.77 - 1.84 t/m3, velocity of 4.4 - 13.5m/s and discharge of 827 - 1248 m3/s, respectively, and also delivered sediment of 16.8 × 104m3, 12.7 - 13.5 × 104m3, 20.5 × 104m3out of the outlet, respectively. These three events all generated a hazard chain, which involved in flash flood, channelized debris flow, dammed lake and outburst flood. The threshold conditions of debris flow blocking Nanya River and forming this hazard chain are that the unit width peak discharge and the deposition volume in river channel are more than 37.0 m3/s and 4500 m3
Monitoring the Transition of Lubrication Status of O/W Emulsion with Electric Resistance Technique
电阻法检测乳化液润滑状态的变化

Qian,Linmao,Meng,Yonggang,Huang,Ping,
钱林茂
,孟永钢,黄平,史小路

摩擦学学报 , 1996,
Abstract: Electric resistance technique is one of the methods used to monitor the lubrication status.The resistance technique has been improved to obtain the time ratio of the metal to metal contact under mixed lubrication regime for a sliding friction system.The method was applied to monitor the transition of lubrication status with O/W emulsion.The influences of concentration and load on the capability of film formation of emulsion have been studied experimentally.The results showed that from the measurement of the time ratio of metal contact,the transition of lubrication status can be monitored and the corresponding critical transition velocity can be detected.By comparison of the experiment result with the theoretical predictive value of the film thickness,it can be concluded that emulsion can form an oil pool in line contact region where the oil concentration is much higher than its bulk nominal value.Therefore emulsion lubrication has some characteristics of oil pool lubrication.
Document Analysis of Correlation between Climate and Stroke  [PDF]
Hongwei Li, Yonggang Qian, Shubi Wang, Hairong Zhang, Wenfang Gou, Mingzhu Niu, Di Yu, Ruijie Wu, Liqun Gao, Baofeng Chi, Qingxia Wang, Wenli Hao, Wuyuntana Li, Tao Yan, Liwei Niu, Yan Liu, Jing Zhao, Yuan Jin, Maolin Du, Juan Sun
Open Journal of Epidemiology (OJEpi) , 2019, DOI: 10.4236/ojepi.2019.91008
Abstract: Aim: The aim of the research is to determine characteristic of the correlation between climate and stroke through the analysis of relevant documents. Methods: We found 115 researches of temperature and season on stroke mortality/incidence and these were categorized according to location, meteorology, date span, data source and research sites’ latitudes. We divided the globe into 5 temperature zones based on latitude ranges: 0 - 10, 10 - 23.5, 23.5 - 40, 40 - 50, and >50 degrees, and allotted a zone to each country. Stroke mortality by five temperature zones was calculated per 100,000 people. Results: 70% of the researches came from latitudes greater than 40 degrees with 92% of researches located in Europe, USA, and Asia. The mortality range was 42 - 63 per 105 individuals within latitudes 0 - 40 degrees. In latitudes 40 - 66.5 degrees, a linear upward trend (y = 69.82x 22.823, R2 = 0.99) was noticed. More than 75% of the research reports indicated a negative correlation between climate and stroke, and the proportion was almost 6 and 7 times greater than that of the fluctuation and non-correlation, respectively. The most frequently used research methods were regression analysis and time series analysis. Conclusion: All of the research results confirmed that lower temperature is associated with higher mortality and incidence of stroke, while higher latitude is correlated with higher stroke mortality, consistent with the temperature zones.
Death Characteristics of Neurological Diseases in Inner Mongolia between 2008 and 2015  [PDF]
Yujia Ma, Yonggang Qian, Zhiqiang Sun, Mingzhu Niu, Du Yu, Hongwei Li, Ruijie Wu, Ying Yang, Hairong Zhang, Xiaoling Sun, Qingxia Wang, Lei Jia, Jing Wen, Yu Feng, Maolin Du, Juan Sun
Open Journal of Preventive Medicine (OJPM) , 2019, DOI: 10.4236/ojpm.2019.93003
Abstract: Background: There are no studies of death from neurological diseases found, however, neurological diseases were the leading cause of disability-adjusted life years in 2015 worldwide. Aim: The scientific aim of this study is to analyze the death characteristics of neurological diseases in Inner Mongolia occurring between 2008 and 2015. Methods: The data collected from Death Registry System (DRS) were categorized by gender, ethnicity, age, and death location. The subjects were divided into age groups for every 10 years from the age of 20. Mortality and gender: age-specific mortality was calculated for every 100,000 people from 2008 to 2015. Results: We found that Alzheimer’s disease has the highest proportion which equated to over one-fifth of all neurological diseases. Males displayed a higher mortality rate than females in all neurological diseases. The neurological diseases mortality showed a total potential year of life lost (PYLL) of about 20,151 years, and it was 2.03 times higher for male than that for female. The average potential years of life lost (APYLL) showed 17.72 years, and APYLL in males was 3.34 years longer than in females. More than 60% of the deaths resulting from the neurological disease occur at home for both males and females. Conclusion: Alzheimer disease is the most serious disease of all neurological diseases, however, cerebral palsy and epilepsy also displayed the highest loss of life for residents. Mortality of neurological diseases was generally higher in males than in females, and this increased with age.
Page 1 /10338
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.