Journal of University of Chinese Academy of Sciences

Multiple positive solutions for a three-dimensional Kirchhoff-type problem with a Hardy term

LIU Xing, SUN Yi-Jing

2012, 29 (5): 577-585. DOI: 10.7523/j.issn.2095-6134.2012.5.001

We investigate the following three-dimensional Kirchhoff-type problem
where Ω is a smooth bounded domain in R³, 0∈Ω, 0 < q < 1, 0 ≤ s < 1, 4 < p < 2^*(s)=2(3-s), parameters a,b,λ > 0. We have established the existence of multiple positive solutions to the problem by using variational methods.

Perturbations for property (ω)

XIN Qiao-Ling, CAO Xiao-Hong

2012, 29 (5): 586-593. DOI: 10.7523/j.issn.2095-6134.2012.5.002

Abstract ( 904 ) PDF (KB) ( 4 )

In general, property (ω) holding for T is not transmitted to the perturbation T+K, even when K is a finite-rank operator or compact operator. We discussed the sufficient and necessary conditions for property (ω) and its stability by means of the variant of the essential approximate point spectrum and the induced spectrum of consistency invertibility. Using these results, we studied the case of algebraically quasi-class A operators.

Oscillation for certain second-order damped differential equations with continuous deviating arguments

LIN Wen-Xian

2012, 29 (5): 594-598. DOI: 10.7523/j.issn.2095-6134.2012.5.003

Abstract ( 946 ) PDF (KB) ( 3 )

We obtain sufficient conditions for the oscillation of all solutions of the nonlinear second-order damped functional differential equations with continuous deviating arguments. This work generalizes and improves some known results. The main results are illustrated by two examples.

Molecular dynamic simulation study on thermal transport coefficients of solid materials

WANG Zeng-Hui, ZHAO Kai-Xuan, NI Ming-Jiu

2012, 29 (5): 599-604. DOI: 10.7523/j.issn.2095-6134.2012.5.004

Abstract ( 1374 ) PDF (KB) ( 5 )

NEMD and EMD simulations were performed to calculate thermal conductivities of solid materials. We used 12/6 L-J potential model for nonmetallic material argon and MEAM potential model for metal materials tungsten. Simulation results show that the thermal conductivities of nonmetal material argon are in good agreement with experimental results but the thermal conductivities of tungsten are 1-2 orders smaller than experimental results. Incorporation of free electron effect can lead to accurate thermal conductivity of tungsten.

Insights into protein-protein interaction by free energy calculation for human MCL-1 with its BH3 α-helix complex

LIU Guang, LI Liang, ZHAO Run-Ning, CHEN Hang, LI Dan, HAN Ju-Guang

2012, 29 (5): 605-613. DOI: 10.7523/j.issn.2095-6134.2012.5.005

Abstract ( 1446 ) PDF (KB) ( 4 )

MM-PBSA approach is applied to evaluate the binding affinities for the MCL-1 complexes with the wild-type and hydrocarbon-stapled MCL-1 BH3 peptides. The hydrophobic effect is the main contribution to the stabilization. Moreover, the interactions are reinforced by additional electrostatic interactions. This study gives insight into protein-protein interaction mechanism at the atomic level.

Regional competitive industries in Beijng and their evolution based on sky-line diagram of input-output technique

TENG Fei, LIU Yi, GUO Teng-Yun, DONG Guan-Peng

2012, 29 (5): 614-620. DOI: 10.7523/j.issn.2095-6134.2012.5.006

Abstract ( 1176 ) PDF (KB) ( 11 )

The competitive industries play the leading role in the regional economic development. Using sky-line analysis method and considering the new perspective of internal and external demands, we identify and analyze the competitive industries in Beijing. The results indicate that from 1997 to 2007 the capital and technology-intensive manufacturing industries and the knowledge-intensive producer's services become the competitive industries while the resource and labor-intensive industries the inferior-position industries.

Analysis and assessment of sustainability of industrial system of resource-based city: a case study of Panjin city

YAN Chang-Ping, MA Yan-Ji

2012, 29 (5): 621-629. DOI: 10.7523/j.issn.2095-6134.2012.5.007

Abstract ( 951 ) PDF (KB) ( 2 )

Based on the analyses of the internal and external factors, an index system for assessment on sustainability of industrial systems of resource-based cities is proposed. The sustainability of the industrial system of Panjin is calculated by using the fuzzy integrate judgment (FIJ) method, and the driving factors are studied based on the grey coloration coefficient analysis. The results indicate that Panjin's industrial system sustainability experienced a process of "rise-fall-rise" from 1998 to 2007. The grey correlation analysis shows that industrial structure and industrial efficiency are the two main indexes which have significantly large impacts on sustainability. Since the industrial structure affects the other factors, the structure factor is the most important factor.

Multi-channel phase error calibration for microwave imaging system based on array antennas

HAN Kuo-Ye, WANG Yan-Ping, TAN Wei-Xian, HONG Wen

2012, 29 (5): 630-635. DOI: 10.7523/j.issn.2095-6134.2012.5.008

Abstract ( 1206 ) PDF (KB) ( 2 )

The problem of multi-channel amplitude and phase incongruity occurs when array antennas are used in a microwave imaging system. We divide multi-channel phase errors into two categories: the range deviation error and residue constant phase error. The effect of each category of error on imaging is analyzed and a calibration method using strong scattering point calibrator is proposed. All of our analyses and conclusions are verified by the experiments in the ground-based system developed in the National Key Laboratory of Microwave Imaging Technology.

Speckle filtering of polarimetric SAR interferometry data based on classification

QI Wen-Lu, LI Yang, WANG Peng, HONG Wen

2012, 29 (5): 636-643. DOI: 10.7523/j.issn.2095-6134.2012.5.009

Abstract ( 1275 ) PDF (KB) ( 1 )

A speckle filter for polarimetric synthetic aperture radar interferometry data is proposed. By using the unsupervised classification method which combines optimal polarimetric interference coherence with Freeman-Durden decomposition and by selecting the pixels belonging to the same classification as the central pixel and having simiar interferometric phase to the center pixel, the filter can suppress speckle noise well while protect data polarization information and interference information. ESAR data are used in experiment.

Load adaptive CoMP scheduling strategies

ZHANG Jin-Zhu, HONG Pei-Lin, XUE Kai-Ping

2012, 29 (5): 644-651. DOI: 10.7523/j.issn.2095-6134.2012.5.010

Abstract ( 1229 ) PDF (KB) ( 2 )

We focus on the downlink CoMP scheduling technologies of LTE-A. The defects of single CoMP scheduling mode with different system loads are presented. Two scheduling strategies for improving cell throughput are presented. The impact of system load on the performance of different scheduling strategies is studied by performing theoretical analysis and system-level simulation followed by the proposed strategy. The results show that the performance of CoMP technologies is good for different loads and that the proposed optimized scheduling can adapt to them with low complexity, which can lead to a further performance improvement.

BER analysis and optimal modulation mapping scheme selection for two-way DNF relay systems

ZHANG Er-Wei, QIU Ling

2012, 29 (5): 652-658. DOI: 10.7523/j.issn.2095-6134.2012.5.011

Abstract ( 930 ) PDF (KB) ( 5 )

We propose a modulation mapping scheme for matching the two-way relay systems with the improved DNF (denoise-and-forward) scheme, which significantly improves the BER(bit error rate) performance of DNF scheme. We also propose a BER calculation method. Simulation results show that the proposed method for the BER calculation is proper and the proposed modulation mapping scheme is effective.

Multi-cell power allocation algorithm for interference coordination based on harmonic mean fairness

XU Mao, ZHANG Guang-Rong, CHEN Xiao-Hui, WANG Wei-Dong

2012, 29 (5): 659-666. DOI: 10.7523/j.issn.2095-6134.2012.5.012

Abstract ( 1237 ) PDF (KB) ( 3 )

We propose a multi-cell power allocation algorithm based on harmonic mean fairness of users' rate for interference coordination in downlink OFDMA-based wireless cellular system. In order to mitigate the co-channel interference of cell edge users first, we formulate the multi-cell power allocation problem as a non-convex optimization problem with an objective of harmonic mean fairness of users' rate, and propose an iterative algorithm to work out the near-optimal solution to the problem. The algorithm requires cooperation between the adjacent base-stations by exchanging interference messages. Simulation results show that the proposed algorithm achieves a high data rate of cell center users, while greatly enhances the data rate of cell edge users.

An uplink interference coordination scheme by combining HII and OI

ZHANG Guang-Rong, WU Wen-Yin, XU Mao, CHEN Xiao-Hui, WEI Guo

2012, 29 (5): 667-673. DOI: 10.7523/j.issn.2095-6134.2012.5.013

Abstract ( 1465 ) PDF (KB) ( 3 )

An uplink interference coordination scheme by combining HII and OI is proposed for the OFDMA wireless system. While the traditional schemes aim to improve rate of users in the whole network or at the cell edge, the proposed scheme targets the satisfaction of all the users in the network. In practice, high interference indicator (HII) and overload indicator (OI) are combined. The simulation results show that the proposed scheme significantly improves user satisfaction compared with the traditional schemes and it is a good candidate for practical systems.

ECS algorithm for squint sliding spotlight SAR imaging

HAN Bing, ZHANG Yong-Jun, LIU Jia-Yin, ZHANG Wen-Yi

2012, 29 (5): 674-680. DOI: 10.7523/j.issn.2095-6134.2012.5.014

Abstract ( 1717 ) PDF (KB) ( 4 )

A squint imaging model for typical sliding spotlight SAR is proposed. Considering the azimuth space-variant characteristic of Doppler parameters, the basic rationale and the implementation of azimuth data filtering are analyzed. The ECS algorithm, which combines the two-step approach and the traditional CS algorithm, is amended within the squint imaging model. In addition, the choice of its pivotal processing parameters is discussed in detail. Finally, the algorithm is validated by computer simulation.

Design of V-band CMOS injection-locked divide-by-2 frequency divider

DU Ze-Bao, YANG Hao, ZHANG Hai-Ying

2012, 29 (5): 681-685. DOI: 10.7523/j.issn.2095-6134.2012.5.015

Abstract ( 915 ) PDF (KB) ( 4 )

Based on the IBM 90 nm RF CMOS technique, an injection-locked millimeter-wave frequency divider with a locking range from 49.8-55.8 GHz was designed. Inductor, co-planner waveguide (CPW), and microstrip have been compared. Inductor with higher quality factor was used in Oscillator core to improve phase noise. CPW was used in input match network to get broadband match, and it was also used in injection net to reduce layout area. Bias voltage of oscillator core and input transistor was optimized to improve the locking range.

Quality management system model based on process method for modern integrated manufacturing systems

WANG Qiu-Ming, GAO Hui-Ying, LIU Ke-Cheng

2012, 29 (5): 686-692. DOI: 10.7523/j.issn.2095-6134.2012.5.016

Abstract ( 700 ) PDF (KB) ( 5 )

A system model of all quality process based on process method is proposed. The work-flow principle and method are used in the model.The model is studied in the aspects of the organization model, function model, process model, and information model. The model can resolve the difficulties caused by business process change and integration to the other business system, and it enhances adaptability and flexibility. Application of the quality model in a semiconductor enterprise shows its feasibleness.

Polymer additives for protein refolding and their mechanisms

NIU Jian-Lou, LIU Bai-Ling, WANG Bin

2012, 29 (5): 693-698. DOI: 10.7523/j.issn.2095-6134.2012.5.017

Abstract ( 851 ) PDF (KB) ( 2 )

This paper outlines several polymeric additives used in the protein refolding in recent years and their possible assisting mechanisms.

Relationship between pharmic character of warm/cold traditional Chinese medicines and their inhibition to fatty acid synthase

MA Xiao-Feng, LIU Yang, ZHANG San-Guo, CHEN Chuan-Chu, TIAN Wei-Xi

2012, 29 (5): 699-706. DOI: 10.7523/j.issn.2095-6134.2012.5.018

Abstract ( 1310 ) PDF (KB) ( 3 )

We screened the inhibition ability to FAS(fatty acid synthase) for 106 warm and 119 cold TCMs(traditional Chinese medicines) in the Chinese Pharmacopiea. It is found that the frequency of strong inhibition to FAS in warming interior medicines and dissipating interior cold medicines is very high, and that in fire purging, deficiency heat purging, and heat purging-vision improving medicines is very low. The direct effect on the energy metabolism system may be a factor in formation of the warm or cold character of TCM.

Post-nonlinear mixtures BSS based on an improved genetic algorithm

SANG Rui, WU Jie, XU Hua, GUO Qiang

2012, 29 (5): 707-713. DOI: 10.7523/j.issn.2095-6134.2012.5.019

Abstract ( 1029 ) PDF (KB) ( 3 )

Considering the deficiency of nonlinear parameter estimation in post-nonlinear mixtures BSS, we propose a method based on an improved GA. First, the value of a new fitness function is used to reflect on the choice of crossover and mutation probabilities. PE and SA are incorporated in GA. Finally, the linear separation algorithm is applied to estimate the separation matrix. The results indicate that the new method has better performance than conventional algorithms.

Joint synchronization algorithm for FRFT-OFDM system

SHEN Yong, DA Xin-Yu, ZENG Wu

2012, 29 (5): 714-719. DOI: 10.7523/j.issn.2095-6134.2012.5.020

Abstract ( 1080 ) PDF (KB) ( 6 )

Synchronization for the OFDM system is studied. A synchronization algorithm with low complexity for joint carrier frequency, sampling frequency, and symbol timing is proposed based on the property of LFM convergent energy in fractional Fourier domain. The three kinds of offset are estimated by locating symmetry point caused by LFM inserted in OFDM symbol. The simulation results show that the performance of the proposed algorithm is improved when the LFM length increases and it is better than those of other similar algorithms.

Current Issue