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Search Results: 1 - 10 of 124362 matches for " Ming Zhang "
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Response Rate of a Static Charge outside a High-Dimensional Schwarzschild Black Hole  [PDF]
Ming Zhang
Journal of Applied Mathematics and Physics (JAMP) , 2018, DOI: 10.4236/jamp.2018.68140
Abstract: In present paper, by using the quantization of an electromagnetic field in the background of static spherically symmetric d-dimensional spacetime in the Boulware vacuum, we calculated the response rate of a static charge outside d-dimensional Schwarzschild black hole in the low-frequency regime, which can be expressed as the summation of hypergeometric functions.
A Bayesian Quantile Regression Analysis of Potential Risk Factors for Violent Crimes in USA  [PDF]
Ming Wang, Lijun Zhang
Open Journal of Statistics (OJS) , 2012, DOI: 10.4236/ojs.2012.25068
Abstract: Bayesian quantile regression has drawn more attention in widespread applications recently. Yu and Moyeed (2001) proposed an asymmetric Laplace distribution to provide likelihood based mechanism for Bayesian inference of quantile regression models. In this work, the primary objective is to evaluate the performance of Bayesian quantile regression compared with simple regression and quantile regression through simulation and with application to a crime dataset from 50 USA states for assessing the effect of potential risk factors on the violent crime rate. This paper also explores improper priors, and conducts sensitivity analysis on the parameter estimates. The data analysis reveals that the percent of population that are single parents always has a significant positive influence on violent crimes occurrence, and Bayesian quantile regression provides more comprehensive statistical description of this association.
Feiyanning Decoction down-regulates the expressions of phosphorylated Akt and hypoxia inducible factor-1α proteins in transplanted lung adenocarcinoma in nude mice
Ming ZHANG
Zhong Xi Yi Jie He Xue Bao , 2008,
Abstract: Objective: To observe the effects of Feiyanning Decoction, a compound traditional Chinese herbal medicine, in inhibiting the growth of transplanted A549 tumors in nude mice and the expressions of p-Akt and HIF-1α in A549 tumors. Methods: Thirty-two nude mice were transplanted with human lung adenocarcinoma cells (A549 cells) to make the mice model, and then randomly divided into four groups: untreated group (n=8), diamminedichloroplatinum (DDP) group (n=8), Feiyanning group (n=8) and DDP plus Feiyanning group (n=8). The nude mice in DDP group and DDP plus Feiyanning group were treated with DDP 0.1 mg by peritoneal injection on the 1st, 3rd and 5th day after model establishment. The nude mice in the Feiyanning group and the DDP plus Feiyanning group were treated with Feiyanning Decoction for 21 days. Reverse transcription polymerase chain reaction (RT-PCR) was used to detect the expression of HIF-1α mRNA in tumors, and immunohistochemical method was used to detect the expressions of p-Akt and HIF-1α proteins in tumors. Results: The inhibition rates of tumor in Feiyanning group and DDP plus Feiyanning group were 34.17% and 64.38% respectively. RT-PCR showed that the expression level of HIF-1α mRNA in DDP plus Feiyanning group was lower than that in the untreated group (P<0.05). Immunohistochemical staining showed that the optical density (OD) indexes of HIF-1α in DDP group, Feiyanning group and DDP plus Feiyanning group were lower than that in the untreated group (P<0.01). The expressions of p-Akt in the Feiyanning group and DDP plus Feiyanning group were lower than that in the untreated group either (P<0.05). Conclusion: Feiyanning Decoction is effective in inhibiting the growth of lung cancer. And the effect of inhibiting the expression of HIF-1α protein by Feiyanning Decoction may correlate with down-regulation of p-Akt.
Effects of stimulus intensity on low-frequency toneburst cochlear microphonic waveforms
Ming Zhang
Audiology Research , 2013, DOI: 10.4081/audiores.2013.e3
Abstract: This study investigates changes in amplitude and delays in low-frequency toneburst cochlear microphonic (CM) waveforms recorded at the ear canal in response to different stimulus intensities. Ten volunteers aged 20-30 were recruited. Low-frequency CM waveforms at 500 Hz in response to a 14-ms toneburst were recorded from an ear canal electrode using electrocochleography techniques. The data was statistically analyzed in order to confirm whether the differences were significant in the effects of stimulus intensity on the amplitudes and delays of the low-frequency CM waveforms. Electromagnetic interference artifacts can jeopardize CM measurements but such artifacts can be avoided. The CM waveforms can be recorded at the ear canal in response to a toneburst which is longer than that used in ABR measurements. The CM waveforms thus recorded are robust, and the amplitude of CM waveforms is intensity-dependent. In contrast, the delay of CM waveforms is intensity-independent, which is different from neural responses as their delay or latency is intensity-dependent. These findings may be useful for development of the application of CM measurement as a supplementary approach to otoacoustic emission (OAE) measurement in the clinic which is severely affected by background acoustic noise. The development of the application in the assessment of low-frequency cochlear function may become possible if a further series of studies can verify the feasibility, but it is not meant to be a substitute for audiometry or OAE measurements. The measurement of detection threshold of CM waveform responses using growth function approach may become possible in the clinic. The intensity-independent nature of CMs with regards to delay measurements may also become an impacting factor for differential diagnoses and for designing new research studies.
Classification of Power Quality Disturbances Using Wavelet Packet Energy Entropy and LS-SVM  [PDF]
Ming Zhang, Kaicheng Li, Yisheng Hu
Energy and Power Engineering (EPE) , 2010, DOI: 10.4236/epe.2010.23023
Abstract: The power quality (PQ) signals are traditionally analyzed in the time-domain by skilled engineers. However, PQ disturbances may not always be obvious in the original time-domain signal. Fourier analysis transforms signals into frequency domain, but has the disadvantage that time characteristics will become unobvious. Wavelet analysis, which provides both time and frequency information, can overcome this limitation. In this paper, there were two stages in analyzing PQ signals: feature extraction and disturbances classification. To extract features from PQ signals, wavelet packet transform (WPT) was first applied and feature vectors were constructed from wavelet packet log-energy entropy of different nodes. Least square support vector machines (LS-SVM) was applied to these feature vectors to classify PQ disturbances. Simulation results show that the proposed method possesses high recognition rate, so it is suitable to the monitoring and classifying system for PQ disturbances.
The automatic processes of earthquake-related stimulus: Comparison at different time points after the Wenchuan earthquake  [PDF]
Ming Lei, Jiang Qiu, Qinglin Zhang
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.58112
Abstract:

Trauma experience not only could predict long-term physical and mental health problems, but also could have impact on the cognitive processes. Modified Stroop task and subliminal masked priming task were used to examine the automatic cognitive processing of earthquake-related stimulus (disaster-related, rescue-related, and earthquake-unrelated words) of healthy undergraduates at one month and two years since the Wenchuan earthquake happened, who came from the worst-hit areas of the Wenchuan earthquake. The results showed that the earthquake interference effects were showed in modified Stroop task and reversed priming effects were found in subliminal masked priming task at one month after the Wenchuan earthquake. However, two years later, earthquake interference effects and reversed priming effects were not found in the same experiments. The results showed the automatic cognitive processing of healthy subjects experienced trauma was affected by the earthquake episodic memory, and these interference effects were weakened with the passage of time.

Presbycusis: A Critical Issue in Our Community  [PDF]
Ming Zhang, Nahla Gomaa, Allan Ho
International Journal of Otolaryngology and Head & Neck Surgery (IJOHNS) , 2013, DOI: 10.4236/ijohns.2013.24025
Abstract:

Hearing is an important sensation to the elderly as it promotes their quality of life and maintains their safety and wellness. For example, healthy hearing lets the elderly catch alarm sounds, stay alert to danger whilst asleep, listen in the dark, detect sounds from behind, communicate efficiently with other people, and maintain links to the world via telephone and radio, especially after retirement. However, age-related hearing loss, i.e., presbycusis, seems to become a growing problem in our community. The purpose of this study is to demonstrate whether presbycusis is a critical issue in our community. To achieve this purpose, the data in the literature as well as in the websites sponsored by hearing-related professional associations and sponsored by related government’s departments have been searched and reviewed. The data resulted from the review show a high prevalence of presbycusis, an ever-growing senior population, an incredible increase in hearing impairment and presbycusis population in the next two decades, a rank as high as at the third place for the prevalence of presbycusis among chronic health conditions in elderly resident facilities, and an alarmingly negative effect of presbycusis on mental health, social life, speech perception and hearing-related areas in the brain. These findings demonstrate that hearing loss in the elderly is a critical issue in our community. The etiology, clinical significance, management of presbycusis, prevention, and access of presbycusis population to assistive devices are also overviewed and discussed.

A Novel Integrated Circuit Driver for LED Lighting  [PDF]
Yanfeng Jiang, Dong Zhang, Ming Yu
Circuits and Systems (CS) , 2014, DOI: 10.4236/cs.2014.57018
Abstract: A novel integrated circuit for driving LED lighting has been proposed, designed and fabricated. Besides the typical parts of LED driver, an integral part was added at the output terminal of error amplifier in the driver. In this way, a novel average current mode can be set up to take the place ordinary peak current control mode. In addition, a BUCK low-level topology was adopted, too. It can be used to drive up to eight 1 W HB LED lights with 350 mA constant current. In this way, the LED driver displays high performance, in which output current with less 1% error and total efficiency as high as 96%. The feasibility of the design has been verified by actual measurement on the fabricated chip.
Semi-Circle Theorem of Unstable Spectrum Distribution of Heterotropic Perturbation and the Upper Bound Estimation of Its Growth Rate
斜交型不稳定谱点分布侧半圆定理及其增长率上界的估计

Zhang Ming,Zhang Lifeng,
Zhang Ming
,Zhang Lifeng

大气科学进展 , 2002,
Abstract: Based on the theoretical analysis on the unstable spectrum distribution of heterotropic perturbation, the semi-circle theorem of such spectrum distribution is obtained -- the spectrum distributed within an upper semi-circle domain with radius R0 and taking origin as its circle center in the complex plane, and the upper bound estimation of growth rate is given simultaneously. It is found that the smaller the horizontal scale of perturbation is, the higher the model top located, the greater the estimated value of upper bound of such growth rate is. Also the increase of vertical shear of wind and latitude have the positive contribution to the increase of such growth rate. Finally when stratified stability decreases, the relative maximal growth rate increases, while the maximal growth rate decreases instead.
Effect of different atmospheres on dry friction behavior of steel sliding against brass at high speed
Ming Qiu,YongZhen Zhang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0575-7
Abstract: The atmosphere components have an influence on tribological behaviors of tribo-pairs. Through changing the atmosphere component, the effect of atmosphere component on the tribological behaviors of CrNiMo steel against brass at high sliding velocity was investigated. The wear test was carried out on a high-speed friction and wear test rig whose test atmosphere could be controlled. The tests were performed at four sliding velocities (30, 40, 50, 60 m/s), one contact pressure (1.33 MPa) and two atmosphere components (N2 or O2). The morphologies of the worn surfaces of various pins were observed with a scanning electron microscope. The chemical compositions of the surfaces and subsurfaces for steels were determined with an energy dispersion spectroscopy. The results showed that the wear rate of the steel pins were low all the time with the sliding velocity increasing in oxygen atmosphere, and that the wear rate of the steel pin in nitrogen atmosphere was higher than that of the steel pin in oxygen atmosphere. It was found that the thin and compact oxidation layer formed on the worn surface of the steel in oxygen atmosphere played a key role in wear resistance. However, the wear rate of the steel pin increased rapidly with the sliding velocity increasing in nitrogen atmosphere, which was attributed to the thick and loose surface layer formed on the worn surface of the steel.
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