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Search Results: 1 - 10 of 105154 matches for " Jianhua Zhang "
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Review of wideband MIMO channel measurement and modeling for IMT-Advanced systems
JianHua Zhang
Chinese Science Bulletin , 2012, DOI: 10.1007/s11434-012-5203-2
Abstract: In October 2005, the next generation mobile communication system was officially named as the International Mobile Telecommunications-Advanced (IMT-Advanced) by the ITU Radiocommunication Sector (ITU-R). Wideband multiple input and multiple output (MIMO) channel models in multiple propagation environments are fundamental for IMT-Advanced systems and such research has been initiated since 2003. The research challenges come from the fact that the wider bandwidth (20–100 MHz) and the advanced multiple antenna technology have been proposed for the IMT-Advanced system, thus leading to higher sampling rates and multiple spatial propagation channels. In this review, four aspects of wideband MIMO channel measurement and modeling are discussed: (1) radio channel measurement procedure and equipment; (2) large scale fading models; (3) small scale fading models; and (4) MIMO channel models. In particular, the large scale fading affected by the carrier frequency is investigated for urban macrocells and it shows that the higher carrier frequency results in greater loss for non-line-of-sight (NLoS) conditions in the cities of China, for which the frequency dependent factor is 32.1. Moreover, the dense and the obviously higher buildings also lead to a larger angle spread (AS) of both the angle of arrival and angle of departure in urban macrocell scenarios. The results indicate that there is the potential to explore the MIMO technique for an IMT-Advanced system with larger ASs, which would lead to the high system capacity. The progress on MIMO models is described and some methods for simplifying geometry-based stochastic channel models (GBSM) are proposed. Finally future research topics on channel measurement and modeling are identified.
Lysosomal function in neurodegenerative diseases
Zhang Jianhua
Molecular Neurodegeneration , 2012, DOI: 10.1186/1750-1326-7-s1-o2
Abstract:
The Effect of In-Game Advertising in SNS on Brand Equity  [PDF]
Jianhua Yang, Meizhen Zhang, Zhiqin Zou
Journal of Service Science and Management (JSSM) , 2015, DOI: 10.4236/jssm.2015.81013
Abstract: In recent years the boom of SNS has bestowed in-game advertising in SNS with great attention from media and the public. This paper explores how IGA in SNS affects brand equity, and how brand familiarity moderates the relationship between IGA in SNS and brand equity. The results indicate that: 1) IGA in SNS has positive effects on brand awareness, brand association and perceived quality. However, such effect on brand loyalty is not significant. 2) Brand familiarity negatively moderates the effect of IGA in SNS on brand awareness, perceived quality and brand association while the effect on brand loyalty is not significant.
Can Micro-Credit Promote Financial Inclusion? The Evidence from China  [PDF]
Jianhua Yi, Ran Zhang, Feng Guo
Journal of Financial Risk Management (JFRM) , 2018, DOI: 10.4236/jfrm.2018.74023
Abstract: This paper offers an analysis of the effect of micro-credit to financial inclusion. We use the survey data of Shandong Province in China since 2010 to 2016, and measure the index of financial inclusion to build the sample for empirical study. This paper examines the role of micro-credit for enlarging the coverage of financial service and decreasing the financial cost. Finally, we give the evidence that the development of micro-credit has the positive effect on promoting the financial inclusion.
A Self-adapted Anycast Routing Algorithm Based on Mobile Agent in Wireless Sensor Network
Nan Zhang,Jianhua Zhang
Journal of Networks , 2011, DOI: 10.4304/jnw.6.2.206-213
Abstract: To reduce the transmissions among sensor nodes and prolong the lifecycle of the wireless sensor network, the immune theory and anycast technique were brought into the mobile agent routing mechanism, and an immune-based MA anycast routing algorithm was put forward. In this algorithm, the diversity and self-adaptation characters of artificial immune system were used to find out the optimal data source searching order, and then the anycast strategy was used to select a node in multiple sensing nodes of a data source. MA migrated in the nodes which was satisfied the energy conditions.
Study of Supper Resolution Processing Methods for Thick Pinhole Image  [PDF]
Hongwei Xie, Faqiang Zhang, Jianhua Zhang, Zeping Xu, Linbo Li
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.42030
Abstract:

An image super resolution reconstruction method was used to improve the spatial resolution of the thick pinhole imaging system and to mitigate the limitations of the image spatial resolution of the hardware of the image diagnostic system. The thick pinhole is usually applied into the diagnostics of the high energy neutron radiation image. Due to the impacts among its energy flux, spatial resolution and effective field of view, in dealing with the large area radiation source, the spatial resolution of the thick pinhole neutron image cannot meet the requirements for high precision modeling of the radiation source image. In this paper, the Lucy-Richardson image super resolution reconstruction method was used to simulate the thick pinhole imaging and super resolution image reconstruction. And the spatial resolution of the image could be increased by over three times after the image super resolution reconstruction. Besides, in dealing with the pseudo-noise, plum blossom shape appeared in the image super resolution reconstruction. The analysis of the source of the pseudo-noise was made based on the simulation of the image reconstruction under various conditions according to the characteristics of the thick pinhole image configuration.

Validation of Antenna Modeling Methodology in IMT-Advanced Channel Model
Jianhua Zhang,Chun Pan
International Journal of Antennas and Propagation , 2012, DOI: 10.1155/2012/282797
Abstract: In this paper, the antenna modeling method in the International Mobile Telecommunications-Advanced (IMT-Advanced) channel model is validated by field channel measurements in the indoor scenario at 2.35?GHz. First, the 2 × 2 MIMO channel impulse responses (CIRs) are recorded with practical antennas as references. Second, the CIRs are reconstructed from the available IMT-Advanced channel model with field patterns of the practical antennas and updated spatial parameters extracted from the similar scenario measurements. Then comparisons between the field CIRs and the reconstructed CIRs are made from coherent bandwidth, eigenvalue dispersion, outage capacity, and ergodic channel capacity. It is found that the reconstructed results closely approximate real results in the coherent bandwidth and correctly describe the statistical characteristics in frequency domain. Compared to the field CIRs, the spatial correlation of the reconstructed CIRs with both types of antenna have a wider range that causes the underestimation of the 5% channel outage capacity. Due to the negligence of the coupling among the antennas and the near field effect of antenna, this modeling method will have a great impact on the characteristics of radio channels, especially on the spatial characteristics. 1. Introduction Multiple-input multiple-output (MIMO) systems, which deploy spatially separated multiple antenna elements at both ends of the transmission link, have to be considered as one of the most promising approaches for high data rate and more reliable wireless systems without extra bandwidth. It was shown that the potential channel capacity of such MIMO systems grows linearly with antenna pairs in independent identically distributed (i.i.d.) channel model [1, 2], but the channel fading correlation affects the capacity by modifying the distributions of the gains of these parallel channels [3]. According to this, the capacity ultimately depends on the propagation channel model used. Recently, to obtain an accurate channel capacity estimation, many verified channel models [4] were used. In [5], a model based on the Kronecker structure of the channel covariance matrix has been assumed to analyze the channel capacity and was extended to a wideband MIMO channel model in [6]. But in [7], it was confirmed that the Kronecker model cannot describe the multipath structure correctly. For example, the MIMO capacity predicted by the Kronecker model is always below the capacity extracted directly from the filed measurement. Another important wideband MIMO spatial channel model, the International
CAGER: classification analysis of gene expression regulation using multiple information sources
Jianhua Ruan, Weixiong Zhang
BMC Bioinformatics , 2005, DOI: 10.1186/1471-2105-6-114
Abstract: In this study, we use a specific classification method, decision trees, to model transcriptional regulation in yeast with features based on predefined motifs, automatically identified motifs, ChlP-chip data, or their combinations. We compare the accuracies and stability of these models, and analyze their capabilities in identifying functionally related genes. Furthermore, we design and implement a user-friendly web server called CAGER (Classification Analysis of Gene Expression Regulation) that integrates several software components for automated analysis of transcriptional regulation using decision trees. Finally, we use CAGER to study the transcriptional regulation of Arabidopsis genes in response to abscisic acid, and report some interesting new results.Models built with ChlP-chip data suffer from low accuracies when the condition under which gene expressions are measured is significantly different from the condition under which the ChIP experiment is conducted. Models built with automatically identified motifs can sometimes discover new features, but their modeling accuracies may have been over-estimated in previous studies. Furthermore, models built with automatically identified motifs are not stable with respect to noises. A combination of ChlP-chip data and predefined motifs can substantially improve modeling accuracies, and is effective in identifying true regulons. The CAGER web server, which is freely available at http://cic.cs.wustl.edu/CAGER/ webcite, allows the user to select combinations of different feature types for building decision trees, and interact with the models graphically. We believe that it will be a useful tool to facilitate the discovery of gene transcriptional regulatory networks.A major challenge in computational biology is to reveal the cis-regulatory logics of gene expression through analysis of high-throughput genomic data, for example, genomic sequences and microarray gene expression data. A common practice is to first identify puta
Lysosomal function in macromolecular homeostasis and bioenergetics in Parkinson's disease
Lonnie Schneider, Jianhua Zhang
Molecular Neurodegeneration , 2010, DOI: 10.1186/1750-1326-5-14
Abstract: A long-term objective in the study of neurodegenerative diseases is to identify the mechanisms of how cells cope with damage to protein and organelles. Ultimately, this should aid in the design of novel and effective treatment strategies. The failure to clear effectively aged and damaged proteins and organelles is implicated in aging and several neurodegenerative diseases. The lysosome is the high capacity organelle responsible for the normal process of protein and organellar degradation [1-4]. The appearance of aggregated proteins in the cells associated with neurodegenerative diseases is common and suggests a dysfunction in the normal protein degradation pathways including the lysosome [5,6].α-synuclein accumulation is commonly associated with Parkinson's disease. Mutations in this protein or gene amplification cause a small subset of Parkinson's disease cases, with Lewy body formation, neurodegeneration and often an associated dementia [7,8]. Further, in many sporadic Parkinson's patients who do not carry mutations or upregulation of expression, α-synuclein aggregation is also widespread [9,10], implicating a dysfunction of its degradation in neurons. Further, supporting a central role of α-synuclein in disease pathogenesis, its reduction in experimental models is neuroprotective [11-15]. These observations suggest the therapeutic strategy of enhancing lysosomal function in treatment of Parkinson's and other neurodegenerative diseases. This review will summarize our current understanding of Parkinson's disease with respect to α-synuclein aggregation and mitochondrial dysfunction, examine how lysosomal function is regulated and review the evidence supporting the hypothesis that enhancing lysosomal function is neuroprotective.Parkinson's disease is the second most common neurodegenerative disease and the most common movement disorder, affecting 1% of the population above the age of 60. Its clinical features include tremor, muscle rigidity, bradykinesia and postural
Micro-particle deposition and lobar distribution of mass flow in human upper respiratory tract model
JianHua Huang,LianZhong Zhang
Chinese Science Bulletin , 2011, DOI: 10.1007/s11434-010-4305-y
Abstract: A representative human upper respiratory tract model consisting of oropharyngeal and asymmetric tracheobronchial (TB) airways from the trachea (G0) to the main lobar bronchi (G2) was constructed. Laminar-to-turbulent airflow for typical inhalation modes as well as micro-particle transportation, wall deposition and mass flow to lobes was simulated using the CFX10.0 software from Ansys Inc. The numerical particle deposition efficiency of the oropharynx region and two generations (G1 and G2) of TB airways shows great agreement with the experimental data obtained from realistic casts. The particle deposition pattern indicates that inertial impaction is the primary mechanism in the human upper airway, and turbulence dispersion performs crescent influence especially for small particles. The initial positions of particles with different fates are confined to specifically concentrated zones. The particle mass distributions of five lobes are close to airflow distributions. The upper lobes receive fewer particles than lower lobes and the right middle lobe receives the least.
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