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Search Results: 1 - 10 of 44118 matches for " Sheng Hu "
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LA-ICP-MS Calibrations for Intact Rock Samples with Internal Standard and Modified Constant-Sum Methods  [PDF]
Sheng Peng, Qinhong Hu
American Journal of Analytical Chemistry (AJAC) , 2012, DOI: 10.4236/ajac.2012.32024
Abstract: Laser ablation coupled with inductively coupled plasma-mass spectrometry (LA-ICP-MS) calibration was conducted with multiple spot analyses on eleven intact rock samples using both an internal standard (IS) method and a modified constant-sum (MCS) method. Methods were then compared for reported bulk elemental composition of the rocks. The MCS method was based on the sum of eight major elements, which is spatially more stable than one single major ele-ment as used in the IS method, and is quite constant among different rock samples. Calibrations were performed with standard reference materials NIST SRM 610, 612, 614, and 616. Little difference was found between using a single standard and a set of standards, because of the good linearity shown by the reference materials. Comparison of the two calibration methods shows that the MCS method produced better and more stable results than the IS method for heterogeneous samples. With the MCS method, approximately 94% to 95% of the total measurements are within the range of ±100% relative deviation, compared with 82% to 86% with the IS method. The IS method resulted insubstantial overestimations for some rock samples (e.g., 648% for Basalt BCR-2 using NIST SRM 610 as the calibration standard), while the largest deviation with the MCS method was 216% for U in Eagle Ford shale #80 sample. For Quartz latite QLO-1, a relative homogeneous sample, the IS method generated slightly better results than the MCS method. Regardless of method, spatially heterogeneous distribution of elements in the intact rock at the scale of the laser spot is considered to be the main reason for the large relative deviations seen in our work compared to published results.
The impact of frequency aliasing on spectral method of measuring T wave alternans  [PDF]
Di-Hu Chen, Sheng Yang
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.22019
Abstract: In this paper we investigate frequency aliasing in spectral method of measuring T wave alter-nans, which may lead a high false positive rate. Microvolt T wave alternans(TWA) has been evaluated as a means of predicting occurrence of ventricular tachyarrhythmia events and its association with the genesis of ventricular ar-rhythmias has been demonstrated. Nowadays, spectral method is one of the most widely used procedures for measurement of microvolt TWA. In our study, based on the sampling theory, the alternans frequency 0.5 cycles/beat, at which the power of the spectrum is used to calculated the Valt and K score (these two parameters indicate the TWA), is equal to the nyquist frequency. Thus this generates frequency aliasing which will make the power at the alternans frequency (P0.5) be two times of the real magnitude of the original spectrum amplitude. With the assump-tion that the noise spectrum follows the normal distribution, in spectral method of measuring T wave alternans, the measuring standard K score>3 to consider the T wave alternans sig-nificant is only with a p<0.133. By change the standard to K score>6 can solve this problem and make the p value to p<0.0027.
Research on Flight Delay Based on Fuzzy Evaluation Algorithm  [PDF]
Sheng Ma, Xiongbin Wang, Huachuan Hu
Journal of Applied Mathematics and Physics (JAMP) , 2017, DOI: 10.4236/jamp.2017.510163
Abstract: In recent years, since airspace restrictions and the volume of passenger traffic are increasing, the rate of flight delay is rising rapidly and the contradiction about it is outstanding. Flight delay event not only holds up passengers’ time, but also makes the airlines suffer a lot. So a scientific and reasonable guidance is necessary to reduce the delay effect. This paper firstly establishes a method to assess the degree of airport delays and get all factors which caused the flight delays quantification, and ultimately we offer a proposal to deal with the flow factor, which is the principal reason for flight delays.
Evolution of Zygotic Linkage Disequilibrium in a Finite Local Population
Xin-Sheng Hu
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0080538
Abstract: One crucial feature of zygotic linkage disequilibrium (LD) analysis is its direct use of diploid genotyping data, irrespective of the type of mating system. Previous theories from an evolutionary perspective mainly focus on gametic LD, but the equivalent development for zygotic LD is not available. Here I study the evolution of zygotic LD and the covariances between gametic and zygotic LDs or between distinct zygotic LDs in a finite local population under constant immigration from a continent population. I derive the analytical theory under genetic hitchhiking effects or in a neutral process. Results indicate that zygotic LDs (diploid level) are more informative than gametic LD (haploid level) in indicating the effects of different evolutionary forces. Zygotic LDs may be greater than or comparable to gametic LD under the epistatic selection process, but smaller than gametic LD under the non epistatic selection process. The covariances between gametic and zygotic LDs are strongly affected by the mating system, linkage distance, and genetic drift effects, but weakly affected by seed and pollen flow and natural selection. The covariances between different zygotic LDs are generally robust to the effects of gene flow, selection, and linkage distance, but sensitive to the effects of genetic drift and mating system. Consistent patterns exist for the covariances between the zygotic LDs for the two-locus genotypes with one common genotype at one locus or without any common genotype at each locus. The results highlight that zygotic LDs can be applied to detecting natural population history.
An Improved Chirplet Transform and Its Application for Harmonics Detection  [PDF]
Guo-Sheng Hu, Feng-Feng Zhu
Circuits and Systems (CS) , 2011, DOI: 10.4236/cs.2011.23016
Abstract: The chirplet transform is the generalization form of fast Fourier transform , short-time Fourier transform, and wavelet transform. It has the most flexible time frequency window and successfully used in practices. However, the chirplet transform has not inherent inverse transform, and can not overcome the signal reconstructing problem. In this paper, we proposed the improved chirplet transform (ICT) and constructed the inverse ICT. Finally, by simulating the harmonic voltages, The power of the improved chirplet transform are illustrated for harmonic detection. The contours clearly showed the harmonic occurrence time and harmonic duration.
The Asymptotic Study of Smooth Entropy Support Vector Regression  [PDF]
Guo-sheng Hu, Jian-hua Zhang
Intelligent Information Management (IIM) , 2012, DOI: 10.4236/iim.2012.43007
Abstract: In this paper, a novel formulation, smooth entropy support vector regression (SESVR), is proposed, which is a smooth unconstrained optimization reformulation of the traditional linear programming associated with an ε-insensitive support vector regression. An entropy penalty function is substituted for the plus function to make the objective function con- tinuous ,and a new algorithm involving the Newton-Armijo algorithm proposed to solve the SESVR converge globally to the solution. Theoretically, we give a brief convergence proof to our algorithm. The advantages of our presented algorithm are that we only need to solve a system of linear equations iteratively instead of solving a convex quadratic program, as is the case with a conventional SVR, and lessen the influence of the penalty parameter C in our model. In order to show the efficiency of our algorithm, we employ it to forecast an actual electricity power short-term load. The experimental results show that the presented algorithm, SESVR, plays better precisely and effectively than SVMlight and LIBSVR in stochastic time series forecasting.
Luminescence Properties of Phosphate Phosphor: Barium Tungstate Doped with Dy  [PDF]
Peiju Hu, Wei Zhang, Zhengfa Hu, Zuyong Feng, Lun Ma, Xiuping Zhang, Xia Sheng, Jie Luo
Journal of Materials Science and Chemical Engineering (MSCE) , 2016, DOI: 10.4236/msce.2016.47006
Abstract:

A series of barium-tungstate-based phosphors doped with different concentrations of Dy3+ were synthesized by solid-state reaction method. Photoluminescence properties and decay lifetime of Dy3+-doped BaWO4 samples were studied. The results indicated that luminescent properties of BaWO4:Dy3+ depended on the Dy3+ concentration, and the inner energy could transfer from ?to Dy3+. The quality of the light was checked by estimating CIE parameters, and the results showed that BaWO4:Dy3+ was a potential candidate as blue-green luminescent materials in white LED because of its excellent emission spectrum excited by UV light.

Assessing breast cancer risk in women with mammary hyperplasia of different syndromes using mammography
Sheng-fang HU,Sheng-fang HU
Zhong Xi Yi Jie He Xue Bao , 2007,
Abstract:
High sensitive and rapid responsive n-type Si: Au sensor for monitoring breath rate  [PDF]
Xuelan Hu, Jiachang Liang, Xing Li, Yue Chen, Chao Zou, Sheng Liu, Xin Chen
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.210130
Abstract: 125 μm-breath sensor with high sensitivity and rapid response was prepared by using n-type Si: Au material. Its sensitivity coefficient and time constant were 4 V.sec / L and 38 msec, respec-tively. Its working principle was based on ano- malous resistance effect, which not only increa- sed the sensitivity, but also reduced its time con-stant greatly. Its signal processing system can select the breath signals and work stably. Therefore, the small changes of breath system can be measured and, especially, patient’s breath rate can be monitored at a distance.
Pituitary-Thyroid Dysfunction in a Hashimoto’s Encephalopathy Patient  [PDF]
Jing-Sheng Hu, Jian-Jun He, Mei-Kui Zhang
Neuroscience & Medicine (NM) , 2012, DOI: 10.4236/nm.2012.34042
Abstract:

The pathogenesis of Hashimoto’s encephalopathy has not been clearly elucidated and involvement of autoimmune damage has been proposed. We report a 23-year-old man who was emergently hospitalized for paroxysmal syncope and involuntary tremor with normal physical examination except for low heart rate. The patient was characterized by neurological symptoms, mild hypothyroidism, enlarged pituitary gland and extremely elevated thyrotropin, which all were reversed with levothyroxine alone. The case indicated that the pituitary-thyroid dysfunction may play a role in the pathogenesis of Hashimoto’s encephalopathy, hence, evaluation of pituitary gland should be recommended in diagnosis and treatment of Hashimoto’s encephalopathy.

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