Probing the nature of cosmic acceleration

Zhang, Hongsheng,Yu, Heng,Noh, Hyerim,Zhu, Zong-Hong Elsevier 2008 Physics letters: B Vol.665 No.5

<P><B>Abstract</B></P><P>The cosmic acceleration is one of the most significant cosmological discoveries over the last century. The two categories of explanation are exotic component (dark energy) and modified gravity. We constrain the two types of model by a joint analysis with perturbation growth and direct H(z) data. Though the minimal <SUP>χ2</SUP> of the ΛCDM is almost the same as that of DGP, in the sense of consistency we find that the dark energy (ΛCDM) model is more favored through a detailed comparison with the corresponding parameters fitted by expansion data.</P>

HYBRID CHAPLYGIN GAS

ZHANG, HONGSHENG,ZHU, ZONG-HONG,YANG, LIHUA World Scientific 2009 Modern Physics Letters A Vol.24 No.7

<P> Hybrid Chaplygin gas model is put forward, in which the gases play the role of dark energy. For this model the coincidence problem is greatly alleviated. The effective equation of state of the dark energy may cross the phantom divide w = -1. Furthermore, the crossing behavior is decoupled from any gravity theories. In the present model, w < -1 is only a transient behavior. There is a de Sitter attractor in the future infinity. Hence, the big rip singularity, which often afflicts the models with matter whose effective equation of state less than -1, naturally disappears. There exist stable scaling solutions, both at the early universe and the late universe. We discuss the perturbation growth of this model. We find that the index is consistent with observations. </P>

Does Unruh radiation accelerate the universe? A novel approach to the cosmic acceleration

Zhang, Hongsheng,Noh, Hyerim,Zhu, Zong-Hong,Yu, Hongwei Elsevier 2010 Nuclear Physics, Section B Vol. No.

<P><B>Abstract</B></P><P>We present a novel mechanism for the present acceleration of the universe. We find that the temperature of the Unruh radiation perceived by the brane is not equal to the inherent temperature (Hawking temperature at the apparent horizon) of the brane universe in the frame of Dvali–Gabadadze–Porrati (DGP) braneworld model. The Unruh radiation perceived by a dust dominated brane is always warmer than the brane measured by the geometric temperature, which naturally induces an energy flow between bulk and brane based on the most sound thermodynamics principles. Through a thorough investigation to the microscopic mechanism of interaction between bulk Unruh radiation and brane matter, we put forward that an energy influx from bulk Unruh radiation to the dust matter on the brane accelerates the universe.</P>

Brane tachyon dynamics

Zhang, Hongsheng,Li, Xin-Zhou,Noh, Hyerim Elsevier 2010 Physics letters: B Vol.691 No.1

<P><B>Abstract</B></P><P>The dynamics of a tachyon attached to a Dvali, Gabadadze and Porrati (DGP) brane is investigated. Exponential potential and inverse power law potential are explored, respectively. The quasi-attractor behavior, for which the universe will eventually go into a phase similar to the slow-roll inflation, is discovered in both cases of exponential potential and inverse power law potential. The equation of state (EOS) of the virtual dark energy for a single scalar can cross the phantom divide in the branch θ=−1 for both potentials, while the EOS of the virtual dark energy for a single scalar cannot cross this divide in the branch θ=1.</P>

Brane world cosmology in the sourced-Taub background

Zhang, Hongsheng,Noh, Hyerim Elsevier 2009 Physics letters: B Vol.679 No.2

<P><B>Abstract</B></P><P>A new brane world in the sourced-Taub background is proposed. The gravity field equations in the internal source region and external vacuum region are investigated, respectively. We find that the equation of state for the effective dark energy of a dust brane in the source region can cross the phantom divide w=−1. Furthermore, there is a drop on H(z) diagram, which presents a possible mechanism for the recent direct data of H(z).</P>

Novel Approach of Fault Diagnosis in Wireless Sensor Networks Node Based On Rough Set and Neural Network Model

Hongsheng Xu,Ruiling Zhang,Chunjie Lin,Youzhong Ma 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.4

Nodes of wireless sensor network (WSN) will appear various faults, because the influence of many unavoidable factors and environment is very complex and harsh. Rough set can deal with incomplete information, especially in the data reduction, and it is easy to realize low energy consumption problem of on-line fault diagnosis based on WSN node energy Co. This paper adopts attribute reduction algorithm by integrate rough set with neural network model to eliminate WSN node failure, so as to achieve data reduction and to improve the accuracy and efficiency of fault diagnosis purpose. The paper makes use of rough set and neural network to the failure phenomenon of WSN node by using knowledge reduction of discernibility matrix and logic operation, eliminating the redundant attribute WSN node fault. Then, fault decision complex table is built by he classified fault, and finally determine the fault location corresponding to fault phenomenon and repair of the final decision table. The experimental results show that this method improves the robustness of the fault diagnosis, and enhances the practicability of WSN limited energy.

Semantic Annotation of Ontology by Using Rough Concept Lattice Isomorphic Model

Hongsheng Xu,Ruiling Zhang,Chunjie Lin,Wenli Gan 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.2

Semantic annotation is the process based on ontology annotation concept class, attribute and other metadata for cyber source and its various parts. Ontology mapping is to calculate the similarity between two ontology elements. Ontology merging is two or more source ontology merging into a goal Ontology. The basic principle of the concept lattice isomorphic generating is isomorphic to the background of the isomorphic concept lattice, and as concept lattice isomorphic background can generate the concept lattice. This paper analyzes the methods of ontology mapping and merging based on rough concept lattice isomorphic model and presents semantic annotation of ontology by using rough concept lattice isomorphic model. Experiments show that this method is better than the traditional method in semantic annotation accuracy and breadth.

Power Flow Algorithm for Weakly Meshed Distribution Network with Distributed Generation Based on Loop-analysis in Different Load Models

Hongsheng Su,Zezhong Zhang 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

As distributed generation (DG) is connected to grid, there is new node-type occurring in distribution network. An efficient algorithm is proposed in this paper to calculate power flow for weakly meshed distribution network with DGs in different load models. The algorithm respectively establishes mathematical models focusing on the wind power, photovoltaic cell, fuel cell, and gas turbine, wherein the different DGs are respectively equivalent to PQ, PI, PQ (V) and PV node-type. When dealing with PV node, the algorithm adopts reactive power compensation device to correct power, and the reactive power allocation principle is proposed to determine reactive power initial value to improve convergence of the algorithm. In addition, when dealing with the weakly meshed network, the proposed algorithm, which builds path matrix based on loop-analysis and establishes incident matrix of node voltage and injection current, possesses good convergence and strong ability to process the loops. The simulation results in IEEE33 and PG&G69 node distribution networks show that with increase of the number of loops, the algorithm’s iteration times will decrease, and its convergence performance is stronger. Clearly, it can be effectively used to solve the problem of power flow calculation for weakly meshed distribution network containing different DGs.

Novel Approach of Semantic Annotation by Fuzzy Ontology based on Variable Precision Rough Set and Concept Lattice

Hongsheng Xu,Ruiling Zhang,Chunjie Lin,Youzhong Ma 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.4

The paper firstly describes some typical manual and automatic semantic annotation, then analyses strategy of semantic annotation based on ontology. Secondly, this paper proposes semantic hierarchical structure of fuzzy ontology based on Variable Precision Rough Set and concept lattice in order to make up the shortage of traditional semantic annotation methods. Novel algorithm of semantic annotation based on fuzzy ontology for domain Webpage is presented in the paper by comparing ontology data of extractive webpage. Finally, experiments show that this presented algorithm is better than the traditional method in semantic annotation rate of support and recall.

Safety and antifatigue effect of Korean Red Ginseng: a randomized, double-blind, and placebo-controlled clinical trial

Zhang, Li,Chen, Xiaoyun,Cheng, Yanqi,Chen, Qilong,Tan, Hongsheng,Son, Dongwook,Chang, Dongpill,Bian, Zhaoxiang,Fang, Hong,Xu, Hongxi The Korean Society of Ginseng 2019 Journal of Ginseng Research Vol.43 No.4

Background: Korean Red Ginseng (KRG) is widely used for strengthening the immune system and fighting fatigue, especially in people with deficiency syndrome. However, there is concern that the long-term application or a high dose of KRG can cause "fireness" (上火 in Chinese) because of its "dryness" (燥性 in Chinese). The aim of this study was to assess the safety and efficacy of a 4-week treatment with KRG in participants with deficiency syndrome. Methods: This was a 4-week, randomized, double-blind, placebo-controlled clinical trial. A total of 180 Chinese participants were randomly allocated to three groups: placebo control group, participants were given a placebo, 3.6 g/d; KRG 1.8 g and 3.6 g groups. The primary outcomes were the changes in fireness and safety evaluation (adverse events, laboratory tests, and electrocardiogram). The secondary outcomes were the efficacy of KRG on fatigue, which include the following: traditional Chinese medicine (TCM) symptom scale and fatigue self-assessment scale. Results: Of the 180 patients, 174 completed the full study. After 4 weeks of KRG treatment, the Fire-heat symptoms score including Excess fire-heat score and Deficient fire-heat score showed no significant change as compared with placebo treatment, and no clinically significant changes in any safety parameter were observed. Based on the TCM syndrome score and fatigue self-assessment score, TCM symptoms and fatigue were greatly improved after treatment with KRG, which showed a dose- and time-dependent effect. The total effective rate was also significantly increased in the KRG groups. Conclusion: Our study revealed that KRG has a potent antifatigue effect without significant adverse effects in people with deficiency syndrome. Although a larger sample size and longer treatment may be required for a more definite conclusion, this clinical trial is the first to disprove the common conception of "fireness" related to KRG.