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Search Results: 1 - 10 of 36909 matches for " Huiyan Zhao "
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Freidlin-Wentzell’s Large Deviations for Stochastic Evolution Equations with Poisson Jumps  [PDF]
Huiyan Zhao, Siyan Xu
Advances in Pure Mathematics (APM) , 2016, DOI: 10.4236/apm.2016.610056
Abstract: We establish a Freidlin-Wentzell’s large deviation principle for general stochastic evolution equations with Poisson jumps and small multiplicative noises by using weak convergence method.
Yamada-Watanabe Theorem for Stochastic Evolution Equation Driven by Poisson Random Measure
Huiyan Zhao
ISRN Probability and Statistics , 2014, DOI: 10.1155/2014/982190
Abstract: The purpose of this paper is to give a detailed proof of Yamada-Watanabe theorem for stochastic evolution equation driven by pure Poisson random measure. 1. Introduction The main purpose of this paper is to establish the Yamada-Watanabe theory of uniqueness and existence of solutions of stochastic evolution equation driven by pure Poisson random measure in the variational approach. The classical paper [1] has initiated a comprehensive study of relations between different types of uniqueness and existence (e.g., strong solutions, weak solutions, pathwise uniqueness, uniqueness, and joint uniqueness in law) arising in the study of SDEs (see, e.g., [2–4]) and the study is still alive today. New papers are published (see, e.g., [2, 3, 5–7]). In this paper we are concerned with the similar question for stochastic evolution equation driven by Poisson random measure by using the method of Yamada and Watanabe. Yamada and Watanabe's initial work [1] proved that weak existence and pathwise uniqueness imply strong existence and weak uniqueness. For -dimensional case, see [8, 9]. For infinite dimensional stochastic differential equation, Ondreját [6] proved similar result for stochastic evolution equation in Banach space driven by cylindrical Wiener process, where the solutions are understood in the mild sense. Lately, R?ckner et al. [7] proved similar result for stochastic evolution equation in Banach space driven by cylindrical Wiener process under the variational framework. On the other hand, Kurtz [2, 3] obtained a pleasant version of Yamada-Watanabe and Engelbert theorem in an abstract form, which covered most of the work mentioned above. However, we will consider the following concrete stochastic evolution equation by using a different method. In this paper, we will consider the following stochastic evolution equation driven by pure Poisson random measure under the variational framework: This type of equations can be applied to many SPDEs, for example, stochastic Burgers equation, stochastic porous media equation, and stochastic Navier-Stokes equation (see, e.g., [9–13]). We will introduce the above equation precisely in Section 2. Our aim is to obtain this jump-case Yamada-Watanabe theorem; that is, weak existence and strong uniqueness (which will be stated in Section 2) imply strong existence and weak uniqueness and vice versa. We note that there are some differences between the jump-case case and the Brownian motion case. It is well known that a Brownian motion can be treated as a canonical map on or (for some Hilbert space ), while for jump-case we have
Equivalence of Uniqueness in Law and Joint Uniqueness in Law for SDEs Driven by Poisson Processes  [PDF]
Huiyan Zhao, Chunhua Hu, Siyan Xu
Applied Mathematics (AM) , 2016, DOI: 10.4236/am.2016.78070
Abstract: We give an extension result of Watanabe’s characterization for 2-dimensional Poisson processes. By using this result, the equivalence of uniqueness in law and joint uniqueness in law is proved for one-dimensional stochastic differential equations driven by Poisson processes. After that, we give a simplified Engelbert theorem for the stochastic differential equations of this type.
Time structure and dynamics of the insect communities in bush vegetation restoration areas of Zhifanggou watershed in Loess hilly region

Zhang Feng,Zhang Shulian,Cheng Zhijie,Zhao Huiyan,

生态学报 , 2007,
Abstract: The insects were investigated in Zhifanggou watershed, Ansai County, Shaanxi Province, China. The results showed that the insect species varied spatially in the following order: the natural bush forests, the mixed forests and the simple forests. The individual number of insects in Caragana korshinskii was the highest, followed by mixed forests and Hippaphae rhamnoides, and the change range of the insect individuals in the natural bush forests was the smallest. The species number of insects with seasonal changes and the individual number of insects in various types of vegetation can be described by the Univariate cubic equation. The order of the diversity index of the insect communities in various types of vegetation from May to September was the natural bush forests, the mixed forests and the simple forests. The change ranges of the evenness values of the simple forests and the mixed forests were higher, and that of the natural bush forests was smaller. The reverse trend was assumed between the dominance values and the evenness values in the time course. Moreover, the main factors and temporal patterns of the insect communities in the natural bush forests were more complicated, fluctuative and obvious than those in the mixed forests and the simple forests by using the principal component analysis.

Zhao Huiyan,

生态学报 , 1990,
Effects of elicitors on aphid growth and development and on specific genes expression in wheat

ZHU Chuanshu,ZHAO Huiyan,

应用生态学报 , 2006,
Abstract: This paper studied the development duration,adult weight,and mean relative growth rate(MRGR) of aphid Schizapis graminum,and the specific genes expression in wheat variety 98-10-30(Triticum aestivum) after treated with different elicitors.The results showed that needling penetration,aphid feeding and BTH application could shorten the development duration of the aphid and decrease its adult weight,but had no significant effect on aphid MRGR.Different elicitors induced different specific genes expression in quality and quantity.The mRNA of PDF1.2 was increased significantly after aphid feeding,while there was no expression after applying BTH.Aphid feeding and BTH application increased the mRNA of BGL2,but no expression was observed in the control and after needling penetration.The induced resistance had some effects on aphid growth and development,and the response induced by aphid feeding had some similarities but significant differences to that induced by mechanical wounding and BTH application.It could be concluded that the response of aphid to elicitors was a special resistance,and there existed some overlaps or differences between it and mechanical wounding and SAR(systemic acquired resistance).
A Novel Multiinstance Learning Approach for Liver Cancer Recognition on Abdominal CT Images Based on CPSO-SVM and IO
Huiyan Jiang,Ruiping Zheng,Dehui Yi,Di Zhao
Computational and Mathematical Methods in Medicine , 2013, DOI: 10.1155/2013/434969
Abstract: A novel multi-instance learning (MIL) method is proposed to recognize liver cancer with abdominal CT images based on instance optimization (IO) and support vector machine with parameters optimized by a combination algorithm of particle swarm optimization and local optimization (CPSO-SVM). Introducing MIL into liver cancer recognition can solve the problem of multiple regions of interest classification. The images we use in the experiments are liver CT images extracted from abdominal CT images. The proposed method consists of two main steps: (1) obtaining the key instances through IO by texture features and a classification threshold in classification of instances with CPSO-SVM and (2) predicting unknown samples with the key instances and the classification threshold. By extracting the instances equally based on the entire image, the proposed method can ignore the procedure of tumor region segmentation and lower the demand of segmentation accuracy of liver region. The normal SVM method and two MIL algorithms, Citation-kNN algorithm and WEMISVM algorithm, have been chosen as comparing algorithms. The experimental results show that the proposed method can effectively recognize liver cancer images from two kinds of cancer CT images and greatly improve the recognition accuracy. 1. Introduction With the development of computer technology, computer aided diagnosis (CAD) [1] technology used in quantitative analysis of medical imaging arose at the historic moment and became one of the research hotspots in medical imaging. Imageological diagnosis for liver cancer mainly includes four ways, angiography, ultrasonic scan, computed tomography (CT), and magnetic resonance imaging (MRI). In the early diagnosis of liver cancer, the CT image is generally preferred by the doctor [2] because of its high resolution, low damage to human body, and the ability to reflect the pathological position of liver cancer accurately. In traditional image diagnosis, the diagnosis of a mass of CT images brings a radiologist a huge workload. And an omission of a tiny detail because of the differences of visions or experiences may cause a wrong classification [3]. Moreover, liver cancer has the characteristics of difficult treatment, poor curative effect, and high mortality. So, it urgently needs liver cancer CAD to give advisory opinions to the doctor and help improve the correct diagnostic rate. Traditional liver cancer recognition methods in CAD can be roughly divided into two categories, learning-based classification and nonparametric classification. The approach of learning-based
High order volume preserving integrators for three kinds of divergence-free vector fields via commutator
Huiyan Xue
Mathematics , 2013,
Abstract: In this paper, we focus on the construction of high order volume preserving in- tegrators for divergence-free vector fields: the monomial basis, the exponential basis and tensor product of the monomial and the exponential basis. We first prove that the commutators of elementary divergence-free vector fields (EDFVF) of those three kinds are still divergence-free vector fields of the same kind. Assuming then there is only diagonal part of divergence-free vector field of the monomial basis, for those three kinds of divergence-free vector fields, we construct high order volume-preserving inte- grators using the multi-commutators for EDFVFs. Moreover, we consider the ordering of the EDFVFs and their commutators to reduce the error of the schemes, showing by numerical tests that the strategy in [9] works very well.
UV-induced DNA mutation of peach aphid

DU Erxia,GUO Jianwen,ZHAO Huiyan,

应用生态学报 , 2006,
Abstract: By using PCR technique and microsatellite marks,this paper studied the DNA polymorphism of peach aphid(Myzus persicae) under UV-radiation.The fragments of three primers were amplified,and the gene diversity and the rate of loci polymorphisms of their genomic DNA,which could reflect the damage degree of DNA after UV-radiation,were measured.The results revealed that after treated with different radiation intensity(15,30,45 W) and duration(2, 4,6 h),the UV-induced DNA mutations were genetic and could be delivered to F_2 generation.The mutations depended on the interaction of radiation intensity and duration.Variance analysis on the gene diversity and the rate of loci polymorphisms showed that there existed a significant difference between UV-treated and control groups,except the rate of loci polymorphisms under 2 h radiation.The average value of the control was higher than that of 2 h radiation treatment.According to the cluster analysis of the genetic distance,the aphids were divided into three groups,i.e.,control group,2 h(15,30 W) treatment group,and the other,which was consistent with the result of variance analysis.
High-level expression and purification of soluble recombinant FGF21 protein by SUMO fusion in Escherichia coli
Huiyan Wang, Yechen Xiao, Lianjun Fu, Hongxin Zhao, Yaofang Zhang, Xiaoshan Wan, Yuxia Qin, Yadong Huang, Hongchang Gao, Xiaokun Li
BMC Biotechnology , 2010, DOI: 10.1186/1472-6750-10-14
Abstract: By inducing with IPTG, SUMO-FGF21 was expressed at a high level. Its concentration reached 30% of total protein, and exceeded 95% of all soluble proteins. The fused protein was purified by DEAE sepharose FF and Ni-NTA affinity chromatography. Once cleaved by the SUMO protease, the purity of rFGF21 by high performance liquid chromatography (HPLC) was shown to be higher than 96% with low endotoxin level (<1.0 EU/ml). The results of in vivo animal experiments showed that rFGF21 produced by using this method, could decrease the concentration of plasma glucose in diabetic rats by streptozotocin (STZ) injection.This study demonstrated that SUMO, when fused with FGF21, was able to promote its soluble expression of the latter in E. coli, making it more convenient to purify rFGF21 than previously. This may be a better method to produce rFGF21 for pharmaceutical research and development.FGF21 is a potent regulator of glucose homeostasis [1]. It was originally identified as a hormone that stimulates glucose uptake in adipocytes [2]. FGF21 is induced and secreted from the liver upon fasting and acts on adipose tissues to induce metabolic adaptation to fasting[3,4]. Specifically, FGF21 stimulates lipolysis in adipocytes, a process which releases fatty acids into the bloodstream; when they reach the liver, these fatty acids are converted to ketones[3]. FGF21 is free of the proliferative and tumorigenic effects [5-7] that are documented for other members of the FGF family [3,8,9]. Systemic administration of FGF21 reduced plasma glucose, fructosamine, triglycerides, insulin, and glucagon in diabetic rhesus monkeys[10]. FGF21 administration led to significant improvements in lipoprotein profiles, by lowering low-density cholesterol and by raising high-density cholesterol, as well as causing weight loss in the animals [10].In recent years, FGF21 has been described as potential new drug candidate to combat metabolic diseases [5,6]. However, producing FGF21 by traditional techniques, s
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