Pilot Symbol Assisted Weighted Data Fusion Scheme for Uplink Base-Station Cooperation System

( Zhe Zhang ),( Jing Yang ),( Jiankang Zhang ),( Xiaomin Mu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.2

Base Station Cooperation (BSC) has been a promising technique for combating the Inter-Cell Interference (ICI) by exchanging information through a high-speed optical fiber back-haul to increase the diversity gain. In this paper, we propose a novel pilot symbol assisted data fusion scheme for distributed Uplink BSC (UBSC) based on Differential Evolution (DE) algorithm. Furthermore, the proposed scheme exploits the pre-defined pilot symbols as the sample of transmitted symbols to constitute a sub-optimal Weight Calculation (WC) model. To circumvent the non-linear programming problem of the proposed sub-optimal model, DE algorithm is employed for searching the proper fusion weights. Compared with the existing equal weights based soft combining scheme, the proposed scheme can adaptively adjust the fusion weights according to the accuracy of cooperative information, which remains the relatively low computational complexity and back-haul traffic. Performance analysis and simulation results show that, the proposed scheme can significantly improve the system performance with the pilot settings of the existing standards.

Mechanism of shear deformation, failure and energy dissipation of artificial rock joint in terms of physical and numerical consideration

Xuepeng Zhang,Yujing Jiang,Gang Wang,Jiankang Liu,Dong Wang,Changsheng Wang,Satoshi Sugimoto 한국지질과학협의회 2019 Geosciences Journal Vol.23 No.3

The physical and mechanical change processes of rock are closely related to energy transformation, and its deformation and failure is an instability phenomena driven by energy exchange. This study investigated mechanism of shear deformation, failure and energy dissipation of joint using both physical and numerical direct shear tests under constant normal load (CNL) condition. Three kinds of joint surface were artificially prepared. An acoustic emission system was employed to monitor acoustic emission in physical test, and rupture frequency was recorded in numerical test to represent micro-crack development. By research of numerical micro-crack development accompanied with physical acoustic emission results, mechanism of shear deformation and failure of joints were illustrated schematically. By definition of dissipation energy, captured using the particle flow code (PFC2D), energy releasing and dissipation were discussed with microscopic damage evolution of joints. Results showed that joints under shearing present a dissipation trend of four stages including a slow rise stage, a rapid rise stage, a shock rise stage and a rapid decline stage.

Energy Efficiency of Very Large Multiuser MIMO Systems with Transmit Antenna Selection

Jie Li,Shuangzhi Li,Xiaomin Mu,Jiankang Zhang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.6

In this paper, transmit antenna selection is performed to improve the energy efficiency of multiuser large scale MIMO systems, which is necessary for the energy efficiency maximization of large scale MIMO, because the RF chains which are connected with antennas are very expensive and consume a lot of power. However, the consumed power of the large scale MIMO systems should include not only transmit power but also the fundamental power for operating the circuit at the transmitter, because the effect of circuit power consumption is more serious when the transmitter is equipped with massive number of antennas. We evaluate the performance of the energy efficiency in the multiuser case where zero-forcing precoding is used to reduce the inter-user interference. The theoretical analysis indicates that there exists an optimal number of selected antennas to maximize the energy efficiency, and we derive optimal antenna number for different number of users. All the analytical results are verified through both mathematical analysis and numerical simulations.

Tensor-Based Channel Estimation Approach for One-Way Multi-Hop Relaying Communications

( Shuangzhi Li ),( Xiaomin Mu ),( Xin Guo ),( Jing Yang ),( Jiankang Zhang ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

Multi-hop relaying communications have great potentials in improving transmission performance by deploying relay nodes. The benefit is critically dependent on the accuracy of the channel state information (CSI) of all the transmitting links. However, the CSI has to be estimated. In this paper, we investigate the channel estimation problem in one-way multi-hop MIMO amplify-and-forward (AF) relay system, where both the two-hop and three-hop communication link exist. Traditional point-to-point MIMO channel estimation methods will result in error propagation in estimating relay links, and separately tackling the channel estimation issue of each link will lose the gain as part of channel matrices involved in multiple communication links. In order to exploit all the available gains, we develop a novel channel estimation model by structuring different communication links using the PARAFAC and PARATUCK2 tensor analysis. Furthermore, a two-stage fitting algorithm is derived to estimate all the channel matrices involved in the communication process. In particular, essential uniqueness is further discussed. Simulation results demonstrate the advantage and effectiveness of the proposed channel estimator.

D-Galactose Induces a Mitochondrial Complex I Deficiency in Mouse Skeletal Muscle: Potential Benefits of Nutrient Combination in Ameliorating Muscle Impairment

Liao Chang,Xin Liu,Jing Liu,Hua Li,Yanshen Yang,Jia Liu,Zihao Guo,Ke Xiao,Chen Zhang,Jiankang Liu,Xi Zhao-Wilson,Jiangang Long 한국식품영양과학회 2014 Journal of medicinal food Vol.17 No.3

Accumulating research has shown that chronic D-galactose (D-gal) exposure induces symptoms similar to natural aging in animals. Therefore, rodents chronically exposed to D-gal are increasingly used as a model for aging and delay-of-aging pharmacological research. Mitochondrial dysfunction is thought to play a vital role in aging and age-related diseases; however, whether mitochondrial dysfunction plays a significant role in mice exposed to D-gal remains unknown. In the present study, we investigated cognitive dysfunction, locomotor activity, and mitochondrial dysfunction involved in D-gal exposure in mice. We found that D-gal exposure (125 mg/kg/day, 8 weeks) resulted in a serious impairment in grip strength in mice, whereas spatial memory and locomotor coordination remained intact. Interestingly, muscular mitochondrial complex I deficiency occurred in the skeletal muscle of mice exposed to D-gal. Mitochondrial ultrastructure abnormality was implicated as a contributing factor in D-gal-induced muscular impairment. Moreover, three combinations (A, B, and C) of nutrients applied in this study effectively reversed D-gal-induced muscular impairment. Nutrient formulas B and C were especially effective in reversing complex I dysfunction in both skeletal muscle and heart muscle. These findings suggest the following: (1) chronic exposure to D-gal first results in specific muscular impairment in mice, rather than causing general, premature aging; (2) poor skeletal muscle strength induced by D-gal might be due to the mitochondrial dysfunction caused by complex I deficiency; and (3) the nutrient complexes applied in the study attenuated the skeletal muscle impairment, most likely by improving mitochondrial function.

Numerical simulations on hot cracking of rock

Jian Kang,Yang-Sheng ZHAO,Da-hai Zhang 한국멀티미디어학회 2006 한국멀티미디어학회 국제학술대회 Vol.2006 No.-

Using random non-homogeneous the solid-head coupled mathematics model and FEM, For example of granite, changing of thermal dilatability and thermal conduction with uniform distributing, Weibull distributing, study on the changing process on hot cracking of rock it is pointed that the relationship between thermal cracking and random distributing, the relationship between thermal cracking and probability distribution mother relationship between thermal cracking and time t, the changing law of temperature and probability distribution and time.