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Search Results: 1 - 10 of 28137 matches for " Yongping Sun "
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Existence and Uniqueness of Positive Solution for Third-Order Three-Point Boundary Value Problems  [PDF]
Tongchun Hu, Yongping Sun
Advances in Pure Mathematics (APM) , 2014, DOI: 10.4236/apm.2014.46037
Abstract:

This paper is devoted to the study of the existence and uniqueness of the positive solution for a type of the nonlinear third-order three-point boundary value problem. Our results are based on an iterative method and the Leray-Schauder fixed point theorem.

Eigenvalues and symmetric positive solutions for a three-point boundary-value problem
Yongping Sun
Electronic Journal of Differential Equations , 2005,
Abstract: In this paper, we consider the second-order three-point boundary-value problem $$displaylines{ u''(t)+f(t,u,u',u'')=0,quad 0leq tleq 1,cr u(0)=u(1)=alpha u(eta). }$$ Under suitable conditions and using Schauder fixed point theorem, we prove the existence of at least one symmetric positive solution. We also study the existence of positive eigenvalues for this problem. We emphasis the highest-order derivative occurs nonlinearly in our problem.
Existence of Symmetric Positive Solutions for an m-Point Boundary Value Problem
Yongping Sun,Xiaoping Zhang
Boundary Value Problems , 2007, DOI: 10.1155/2007/79090
Abstract: We study the second-order m-point boundary value problem u''(t)+a(t)f(t,u(t))= 0, 00 for i=1,2, ¢ € |,m ¢ ’2 with ¢ ‘i=1m ¢ ’2 ±i<1,m ¢ ‰ ¥3. a:(0,1) ¢ ’[0, ¢ ) is continuous, symmetric on the interval (0,1), and maybe singular at t=0 and t=1, f:[0,1] —[0, ¢ ) ¢ ’[0, ¢ ) is continuous, and f( ¢ …,x) is symmetric on the interval [0,1] for all x ¢ [0, ¢ ) and satisfies some appropriate growth conditions. By using Krasnoselskii's fixed point theorem in a cone, we get some existence results of symmetric positive solutions.
A study on the activity of dermal multipotent stem cells in initiation of wound repair  [PDF]
Jifu Qu, Tianmin Cheng, Yongping Su, Chunmeng Shi, Wei Sun
Journal of Biomedical Science and Engineering (JBiSE) , 2013, DOI: 10.4236/jbise.2013.62014
Abstract:

Background: Wound healing is a process of cell-cell interaction and cell-extracellular matrix interaction. Dermal multipotent stem cells (dMSCs) have the abilities to promote survival and wound healing, but the potential function of dMSCs in wound healing, particularly in the initiation of wound repair, has not been fully understood. Methods: dMSCs and fibroblasts were isolated from neonatal rat dermis and were further purified and expanded. The cell cycles were determined with flow cytometry, while the radiosensitivity was measured by MTT assay. Rats were wounded with a 7-cm incision on the back skin and the wound fluids were collected by inserting two pieces of sterile polyvinyl alcohol sponge (1 cmin diameter and0.4 cmin thickness) subcutaneously into the dorsum of each rat through the midline of incision on the 1st, 2nd, 3rd and 4th day after incision. The effects of wound fluids on the proliferation of dMSCs and fibroblasts were measured with MTT assays. dMSC’s abilities of adhesion and attachment and its migration in response to wound fluids collected on the 1st day after incision were explored by measuring the percentage of floating cells and the cells migrated into wounding area in vitro, respectively. Results: The isolated dMSCs were morphologically homogenous and highly proliferative. Most of the cultured dMSCs were quiescent with few apoptotic cells. Compared with fibroblasts, dMSCs were more sensitive to radiation and more proliferative in response to wound fluids, especially to the wound fluids collected on the 1st day after wounding. Moreover, their abilities to attach, adhere and migrate were significantly enhanced with the early-phase wound fluids. Conclusions: As primitive stem cells, dMSCs are very responsive to wound fluids, which suggests dMSCs’

EXISTENCE OF MONOTONE POSITIVE SOLUTION FOR SECOND-ORDER TWO-POINT BOUNDARY VALUE PROBLEMS
二阶两点边值问题单调正解的存在性

SUN Yongping,
孙永平

系统科学与数学 , 2010,
Abstract: In this paper, the following nonlinear second-order two-point boundary value problem is considered: $$\left\{\aligned & x'(t)+f(t,x(t))=0,\quad 0\leq t\leq 1,\\&x(0)=\xi x(1),\quad x'(1)=\eta x'(0),\endaligned\right.$$where $\xi,\ \eta\in(0,1)\cup(1,\infty),\ f:0,1]\times0,\infty)\to0,\infty)$ is continuous. Under some suitable growth conditions on $f$, the existence of monotne positive solutions for the problem is proved by applying a fixed point theorem due to Avery, Anderson and Krueger.
Existence and Nonexistence of Positive Solutions for a Higher-Order Three-Point Boundary Value Problem
Yongping Sun,Qian Sun,Xiaoping Zhang
Abstract and Applied Analysis , 2014, DOI: 10.1155/2014/513051
Abstract: This paper is concerned with the existence and nonexistence of positive solutions for a nonlinear higher-order three-point boundary value problem. The existence results are obtained by applying a fixed point theorem of cone expansion and compression of functional type due to Avery, Henderson, and O’Regan. 1. Introduction We consider the existence and nonexistence of positive solution to the nonlinear higher-order three-point boundary value problem (BVP for short): with , , are constants with . is continuous. Here, by a positive solution of BVP (1) we mean a function satisfying (1) and for . If , BVP (1) reduces to so-called boundary value problem which has been considered by many authors. For example, Agarwal et al. [1] considered the existence of positive solutions for the singular boundary value problem. Baxley and Houmand [2] considered the existence of multiple positive solutions for the boundary value problem. Yang [3] obtained some new upper estimates to positive solutions for the problem. Existence and nonexistence results for positive solutions of the problem were obtained by using the Krasnosel'skii fixed point theorem. In recent years, the existence and multiplicity of positive solutions for nonlinear higher-order ordinary differential equations with three-point boundary conditions have been studied by several authors; we can refer to [4–19] and the references therein. For example, Eloe and Ahmad in [4] discussed the existence of positive solutions of a nonlinear th-order three-point boundary value problem where , . The existence of at least one positive solution if is either superlinear or sublinear was established by applying the fixed point theorem in cones due to Krasnosel'skii. Under conditions different from those imposed in [4], Graef and Moussaoui in [5] studied the existence of both sign changing solutions and positive solutions for BVP (2). Hao et al. [6] are devoted to the existence and multiplicity of positive solutions for BVP (2) under certain suitable weak conditions, where may be singular at and/or . The main tool used is also the Krasnosel'skii fixed point theorem. Graef et al. in [7, 8] considered the higher-order three-point boundary value problem where is an integer and is a constant. Sufficient conditions for the existence, nonexistence, and multiplicity of positive solutions of this problem are obtained by using Krasnosel'skii's fixed point theorem, Leggett-Williams' fixed point theorem, and the five-functional fixed point theorem. Let be a real Banach space with norm and be a cone of . Recently, Zhang et al. [9] studied
Land Intensive Utilization Evaluation of Linhai Industrial Zone in Xingcheng City
Yongping Sun,Liping Li,Huiyuan Mao
Asian Social Science , 2012, DOI: 10.5539/ass.v8n7p219
Abstract: Rigorously promoting the intensive use of land of industrial zone is of great significance to relieve the contradiction of land supply and demand, and even to guarantee the comprehensive coordinated and sustainable development of local economy and society. This article takes the Linhai Industrial Zone in Xingcheng, Liaoning province as the research object. Combined with the local reality, this essay selects 6 level two indexes and 14 level three indexes from three aspects including the situation of land utilization, land use efficiency and management performance to make an evaluation system and uses the Delphi method to determine the index weight and the evaluation factor score, and to evaluate the intensive use level of lands in the development zone. The results show that the industrial park land intensive utilization degree is the medium level; the land development and utilization intensity is relatively high; land use structure is not reasonable; the land use efficiency still remains to rise.
Natural Language Watermarking Using Chinese Syntactic Transformations
Hong Wang,Xingming Sun,Yuling Liu,Yongping Liu
Information Technology Journal , 2008,
Abstract: In this study, a novel natural language watermarking scheme of Chinese texts based on syntactic transformations is proposed. In the proposed scheme, the so-called sentence weight defined in the study is used to carry the watermark bit. During the embedding process, the transformable sentences are first grouped and then their sequence is permuted to enhance the imperceptibility of watermark bit hiding positions. To improve watermarking reliability and capacity, error correcting coding is also applied.
MIMIC-PPT: Mimicking-Based Steganography for Microsoft Power Point Document
Yuling Liu,Xingming Sun,Yongping Liu,Chang-Tsun Li
Information Technology Journal , 2008,
Abstract: Communications via Microsoft Power Point (PPT for short) documents are commonplace, so it is crucial to take advantage of PPT documents for information security and digital forensics. In this study, we propose a new method of text steganography, called MIMIC-PPT, which combines text mimicking technique with characteristics of PPT documents. Firstly, a dictionary and some sentence templates are automatically created by parsing the body text of a PPT document. Then, cryptographic information is converted into innocuous sentences by using the dictionary and the sentence templates. Finally, the sentences are written into the note pages of the PPT document. With MIMIC-PPT, there is no need for the communication parties to share the dictionary and sentence templates while the efficiency and security are greatly improved.
Layered Design and Collaborative Development of Network System and Its Application in Real-time Information Cluster
Qiudong Sun,Wenxin Ma,Yongping Qiu,Wei Chen
International Journal of Computer Network and Information Security , 2011,
Abstract: In order to achieve the integrated optimization in developing the big network system, this paper presented the concepts and principles of layered design method and collaborative development using of different tools firstly. Then we gave a recommended layered architecture for the distributed computing network system and also analyzed its pros and cons. At last, we extended the distributed computing network system to an information server cluster based on the task scheduling of dynamic and self-adaptive algorithm. The application of real-time information system designed by layered architecture shows that the method proposed in this paper is practical and efficient.
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