Table of Content

20 November 2009, Volume 45 Issue 6

Previous Issue    Next Issue

Regional Differences Evaluation onthe Comprehensive Benefit of Marine Resources Development and Utilization

DUAN Xiaofeng,XU Xuegong

2009, 45(6):  1055-1060. 

Asbtract ( )  

Related Articles | Metrics

The advantages and disadvantages of marine resources utilization can be foundthrough regional differences evaluation, which can be provided as the basis of taking measures to improve comprehensive benefits of marine resources utilization. Eleven coastal provinces of China are studied. Fifteen indices dividedinto 3 groups (economic benefits, social benefits and environmental enefits) are selected to build an index systemfor marine resources utilization evaluation. Based on niche ecostate-ecorole theory, the niche breadths of each province are calculated to represent the different benefits of marine resources utilization. Applying polygon synthesis indicator method for the integrated index calculation, regional differences of the 11 coastal provinces are evaluated for marine resources utilization benefits analysis. The results indicate that regional differences of marine resources utilization benefits are distinct amongthe 11 coastal provinces in China; the predominant provinces in marine resources utilization are Shanghai, Guangdong, and Tianjin, whose resources utilization is more effectivethan other provinces; the integrated indices of comprehensive benefits of the 11 coastal provinces are low as a whole, which indicates that there are great needs to improve the utilization benefits of marine resources; enhancing resources utilization efficiency and resisting marine hazards are the common needs for most coastal provinces.

Research onthe Measurement of the Impact of a Mega-Event on the Awareness of Tourism Attractions in Host City

QI Lina,ZHANG Yi,WU Bihu,SONG Lili

2009, 45(6):  1061-1067. 

Asbtract ( )  

Related Articles | Metrics

To measurethe impact of a mega-event on the awareness of tourism attractions in host city, an approach was developed based upon hyperlink analysis ?Hyperlink Change Analysis. Its idea is based on two assumptions: 1) the larger the number of inlinks of the tourism attraction’s official Web site , the higher its awareness; 2) under general circumstances, the growth of the number of inlinks of tourismattraction’s official site is similar to linear growth. If these two assumptions are correct, then the general growth pattern will be changed by mega-events, so that change of inlinks can measure the impact of a mega-event on the awareness of tourism attractions in host city. The paper explores the feasibility of hyperlink change analysis through researching the change of the number of inlinks of Beijing tourism attractions’official Web site during the Beijing 2008 Olympic Games.

Relationship between Faux Pas Comprehension, Social Interaction Skill and Languagein School-Age Children

MO Shuliang,SU Yanjie,ZHOU Zongkui

2009, 45(6):  1068-1074. 

Asbtract ( )  

Related Articles | Metrics

Ninety-two children of 9-11 years old were measured on Faux Pas comprehension, social interacting skill and language ability. The task was developed to measure individuals’understanding of epistemo logical mental state, emotion and desire. Children’s social skill was measured using the method of Peer-Rated Social-Interaction Skill. Language ability was assessed with Wechsler Child Intelligence Scale-Revised (Chinese version). The results show significant correlations between Faux Pas comprehension and social interaction skill, and between Faux Pas comprehension and language ability, after controlling for age. Regression analysis show a bidirectional relationship between Faux Pas comprehension and social interaction skill. Hierarchical regression analysis show that language ability is a fully mediated factor in the relationship between Faux Pas comprehension and social interaction skill.

Application of Basic Function Methodin Compressible Viscous Flow

PENG Hengchu ,WU Wangyi

2009, 45(6):  925-930. 

Asbtract ( )  

Related Articles | Metrics

The application of basic function method in compressible viscous flowis discussed. By using first order trigonometric function as basic function, the central and upwind schemes of derivative are constructed. The technique of flux splitting method and the combination of central and upwind schemes are utilized to deal with the convection term of compressible Navior-Stokes equation. As for the viscosity term, only central scheme is used. A new basic function scheme for compressible viscous flowis constructed. Several numerical results of two examples for two dimensional and three dimensional axisymmetric compressible viscous supersonic steady flow illustrate the effectiveness of basic function method in dealing with compressible viscous flow.

A Numerical Method for the Contact? Impact Problems of Soil

YANG Lei,MA Wei,YANJun,QU Guangji,LIU Caishan

2009, 45(6):  919-924. 

Asbtract ( )  

Related Articles | Metrics

The authors model soil as an ideal elastic-plastic material, and adopt Drucker-Prager yield criterion to develop a numerical method for solving the contact? impact problems of soil. The relationships between the indentation of the rigid body and the stresses in the normal and tangential directions are established for each discrete element. The numerical results for three kinds of examples agree well with experimental ones. Thus, the method developed is verified.

Envelope Periodic and Solitary Solutions to One Dimensional Gross-Pitaevskii Equationin Bose-Einstein Condensates

GAO Bin,LIU Shikuo,FU Zuntao,LIU Shida

2009, 45(6):  931-936. 

Asbtract ( )  

Related Articles | Metrics

The construction of exact solutions of nonlinear Schrdinger equations plays an important role in understanding the dynamic evolution of Bose-Einstein condensates. The Jacobi elliptic function expansion methodis appliedto construct the envelope periodic solutions to one dimensional Gross-Pitaevskii equation in Bose-Einstein condensates. The envelope periodic solutions can degenerate to the envelope solitary solutions under the limited condition.

Gas-Assisted Etching of Micro-Hole Lattice Array on Lithium Niobate with Focused Ion Beam

XU Xuefeng,YAN Sha,WANG Keming,WANG Xuelin,XUE Jianming,WANG Yugang

2009, 45(6):  937-940. 

Asbtract ( )  

Related Articles | Metrics

Two-dimensional micro-hole lattice arrays with specified structure parameters were fabricated on LiNbO₃ (LN) substrateby means of focused ion beam (FIB) etching, and the influence of etching parameters, such as spot current, etching time full rate, were investaged. In order to etch good quality holes, the authors used gas-assisted etching (GAE) with focused ion beam. The results show that GAE can reduce the effect of redeposition and obtain better hole profile compared with FIB etching. According to simulative calculation, the photonic bandgap of lattice array, etched by GAE with XeF₂, is more close to the ideal photonic bandgap.

Monte Carlo Simulation of Vortex Phase with Disorder

CHEN Shuo,LI Dingping,LIN Hung Yeh,B.Rosenstein

2009, 45(6):  941-946. 

Asbtract ( )  

Related Articles | Metrics

Based on the Ginzburg-Landau model, using lowest Landau level approximation, Monte Carlo simulations are performed to investigate the vortex phase in type II two-dimension super conductors. For the clean system, the first order phase transition from vortex solidto vortex liquidis obtained, which is in agreement with previous works in the literature. In contrast, for the weak disorder system, the Bragg glass phase is observed.

Non-perturbative SpectrumCalculation of Vortex Solid in Type-ⅡSuperconductors

ZHANG Li,CHEN Shuo,CHEN Yu,LI Dingping

2009, 45(6):  947-952. 

Asbtract ( )  

Related Articles | Metrics

The excitations in lattice in type-Ⅱsuperconductors in magnetic field contain acoustic and optical phonons. The acoustic phonon is Goldstone Boson with zero mass. By using Gaussian variational method, the authors calculate dispersion relations of acoustic and optical phonons non-perturbatively based on Ginzburg-Landau model with lowest Landau level approxi mation.

Pinning Effect in the Anomalous Hall Effect of High-Tc Superconductors

HE Li,HU Xiang,XU Xiaolin,GUO Jiandong,LI Chuanyi,YIN Daole

2009, 45(6):  953-957. 

Asbtract ( )  

Related Articles | Metrics

The work on the research of pinning effect in the anomalous Hall effect of high-Tc superconductors is reported. Based on the extended power lawequation and consideringthe pinning effect, two scaling relations are deduced which agree well with the experimental data of different superconductors. Meanwhile, based on the results of TDGL (time dependent Ginzburg-Landau) theory and considering pinning effect, two Hall conductivity equations for superconductors with and without double sign reversal were reported.

A Novel Scheme of Asynchronous Time Slots Allocation for TDD-CDMA Systems

JIN Xiaolu,MA Meng,JIAO Bingli

2009, 45(6):  958-964. 

Asbtract ( )  

Related Articles | Metrics

A novel scheme to enable asynchronous time slots assignment is proposed for TDD-CDMA (time division duplex_code division multiple access) systems. Analysis of inherent inter-cell interference due to asynchrony between adjacent cellsis presented first, including BS-BS and MS-MSinterference. Then, wired connections between base stations are used to construct the adaptive RFinterferences canceller. MS-MS interference is suppressed by time slots allocation to MSs according to their locations. Both theoretical analysis and simulation results show that the inter-cell interference can be decreased to a negligible level and no longer a threat to the system performance. Therefore, the ability of dynamic resource allocation is improved for TDD-CDMA systems.

3D Partial Shape Retrieval Based on Local Bag-of-Words Models

LIU Yi,WANG Xulei,ZHA Hongbin

2009, 45(6):  965-972. 

Asbtract ( )  

Related Articles | Metrics

The authors propose a new 3D shape representation, “local bag-of-words models”and use overlapped “local bag-of-words models”which improves the robustness of the algorithm by avoiding shape segmentation. The detailed steps are also proposed to apply the “Earth Mover’s distance”and “pyramid match kernels”algorithms to quantify partial shape similarity. It proves that the proposed distance measure mitigates the distance under-estimation problemof global bag-of-words model. Finally, the experiments firmly demonstratethe effectiveness of the proposed approach to 3Dpartial shape retrieval.

Analysis and Practice of a SoC Hardware Kernel for MS Windows

ZHENG Yansong,TONG Dong,LI Hao,PANG Jiufeng,WNAG Keyi,CHENG Xu

2009, 45(6):  973-978. 

Asbtract ( )  

Related Articles | Metrics

The authors study a method that develops a SoC hardware kernel for MS Windows. The method captures the basic system function specification of hardware kernel through multiple simulation execution and gradual drawoff, on the premise that the system is MS Windows compatible. The experiment indicates that the complexity of the hardware kernel is simpler drastically than that of the whole system, and that the requirement of hardware kernel among MS Windows versions is different obviously. Moreover, the SoC hardware kernel for MS Windows 98 is verified on the FPGA prototype.

A Novel PTS with Low Complexity

JIAO Yuzhong,WANG Xin’an,NI Xuewen,XU Ying,LIU Xuejiao

2009, 45(6):  979-982. 

Asbtract ( )  

Related Articles | Metrics

The authors present a new scheme to optimize PTS (partial transmit sequence technique) in the aspect of complexity. The new method searches for proper partial transmit sequence and phase factor to reduce the peak of OFDM sequence in each iterative process, thus get an OFDMsequence with low PAPR. Due to its fast convergence, it has low complexity. Simulation result shows that the new PTS has not only lower complexity but also better PAPRreduction performance, which is over 0.28 dB more than iterative PTSin V≥16 when CCDF (complementary cumulative distribution function) is 10 - 4.

A PN-Based Carrier Frequency Offset Estimation Algorithmfor Multiuser OFDM Uplink

REN Shubo,GUO Junqi,WU Jianjun,XIANG Haige

2009, 45(6):  983-988. 

Asbtract ( )  

Related Articles | Metrics

The authors propose a pseudo-noise (PN) sequence-based carrier frequency offset (CFO) estimation algorithmfor multiuser OFDMuplink. In the proposed algorithm, a PN sequence and its circular-shifting versions are considered as training sequences for different users, and then channel parameters with CFO factors from each user to a central base station can be estimatedby virtue of autocorrelation characteristic of the PN sequence. Finally all users’CFO estimates can be acquired simultaneously by calculating channel phase-angle difference between two training periods. The simulation result shows that the proposed algorithm achieves better estimation performance.

A Modified Macro Model of FEFET for FEDRAM Application

LIU Fudong,KANG Jinfeng,AN Huiyao,LIU Xiaoyan,HAN Ruqi

2009, 45(6):  989-994. 

Asbtract ( )  

Related Articles | Metrics

The authors establish an advanced macro-model that can be used to denote the device behaviors of ferroelectric field effect transistor (FEFET) including the dynamic overturn and the double threshold voltages transfer behaviors. The proposed advanced macro model with the simple and easily extracted model parameters can be performedin the HSPICEenvironment. The simulations show that the model can well fit the published experimental data. The proposed model can be used in the design and optimization of FEFET-based dynamic randomaccess memory circuits.

Trends of Precipitation of Different Intensity in China

LIN Yunping,ZHAO Chunsheng

2009, 45(6):  995-1002. 

Asbtract ( )  

Related Articles | Metrics

Based on a daily precipitation dataset of 521 meteorological stations in China, trends of regional average precipitation amounts, precipitation days and daily precipitation intensities of the 9 different precipitation classes, rangingfrom 0.1-4.9 ,5-9.9 , 10- 16. 9 ,17-24. 9 ,25-37.9 ,38- 49. 9 ,50-74. 9 ,75-99.9 mmto over 100 mm, were studied for the period of 1961-2000. The results revealed that,the trends of the lightest precipitation amounts were caused bythe changes of precipitation days, while the changes of the heaviest precipitation amounts were mainly dominated by the precipitation intensity. The analysis on precipitation frequency and the proportion of precipitation amount of each precipitation class showed that, in spite of the decreasing trend in North China and Sichuan Basin, the precipitation frequencies andthe proportions of precipitation amounts in other regions went upward significantly, indicating an increasing contribution of the heavier precipitation to the total precipitation amount.

Comparison and Daytime Cloud Detectionfrom MODIS Data Using a Threshold Rule Based Approach

LI Ying,ZHANG Xianfeng

2009, 45(6):  1003-1011. 

Asbtract ( )  

Related Articles | Metrics

Considering the spectral properties of land covers in the northwest China and the characteristics of the channels of the Moderate Resolution Imaging Spectroradiometer (MODIS), based on a group of threshold rules, this study proposed a daytime cloud detection algorithmto overcome common difficulties of current cloud detection studies in separating thin cloud covers from clean sky when surface reflectance was high, and in identifying small-area cloud covers and those cloud pixels above ice-snow covers. Cloud detection experiments were conducted onthetwo dates MODISdata fromthe Terra Earth Observing Systemin 2008. The result shows that all kinds of cloud cover inthe study area can be well detected using the proposed algorithm. Comparing with the MOD35-2L cloud mask product, this approach can better identify small-area and irregular-shaped cloud covers and the cloud pixels above the ice-snow covers than the MOD35-2L product. Thus, the proposed approach is efficient for daytime cloud detection in arid and semi-arid areas and useful for the preprocessing of MODIS data.

Correction of Atmospheric Effects on Repeat-Pass Interferometric SAR Using MERIS and ASAR Synchronous Data

LI Xiaofan,LI Ying,ZENG Qi ming,ZHAO Yonghong

2009, 45(6):  1012-1018. 

Asbtract ( )  

Related Articles | Metrics

The purpose is to discuss how to correct the atmospheric effects on repeat-pass InSAR. A specific way integrated with MERIS and ASAR was put forward with its elaborate characters andtheory. Taking a differential inter ferogram with test site located in Yangtze River side as a sample, this specific correcting model was applied and tested. Results show that the RMS of deformation in the range direction is obviously decreased and the precision of measurement is enhanced greatly.

An Activity State Based Distributed Task Management Model

YAN Menglong,YANG Zhenzhen,GAO Yong,WU Lun

2009, 45(6):  1019-1024. 

Asbtract ( )  

Related Articles | Metrics

Based on P2P (peer to peer) distributed network architecture, an activity state based distributed task management model is proposed. First, the state of activity, its three characters, change rules of the state, execution process of the task, and the compensation for failed activities are described in detail. Then, based on this model a distributed remote-sensing image processing systemis implemented. Two datasets are used to demonstrate the high performance and its stability of the model. Moreover the model is of strong expandability.

On Vagueness of Cardinal Direction Relationshipsin Difference Cognitive Scenarios

JIN Xin,GENG Haiyan,GAO Yong,LIU Yu

2009, 45(6):  1025-1032. 

Asbtract ( )  

Related Articles | Metrics

Many spatial relationships are inherently associated with vagueness. Much research on vagueness is conducted based on cognitive experiments. Three cognitive experiments, which perform agreement task, verbal description task, and drawing task, are designed and implemented to investigate three types of vagueness in perceptions and communications of cardinal direction relationships. Generally, if a spatial relationship is crisp, the three tasks will lead to the same result. However, if a spatial relationship and its conceptually neighboring relationship are both vague, the subjects will make different answer sin the above three tasks. In this research, the concept of “north”and its neighboring concepts, i.e., “east”and “west”, are focused on. According to the collected data, three types of vagueness: normal vagueness, selective vagueness, and pragmatic vagueness, are identified, and their conceptual membership functions are established. These three types of vagueness demonstrate different characteristics, and will cause semantic distortions in communicating geospatial knowledge.

Exploration of Microwave Remote Sensing Observation about Earthquake Precursors

LUO Xianhan

2009, 45(6):  1039-1045. 

Asbtract ( )  

Related Articles | Metrics

Through analysis of several strong earthquakes in Haicheng, Tangshan and Wenchuan, the author points out that the uncertainty of earthquake forcast lies in the complexity of precursors which are difficult to detect and identify. Single small earthquake precursor does not provide universal forecast meaning. However, comprehensive analysis on a variety of precursors may be of great significance for the short-term earthquake forecast. Further analysis demonstrates, the selection of observation instruments can be more important. Compared with common ground observation for obtaining estimative information of earthquake precursors, the space remote sensing observation for obtaining collateral information of the seismogenic zone, and microwave remote sensing observation in particular, provides many advantages, including big visual field, quick prescription , strong synchronismand working in all weather. Under the condition of using bean switching method, the microwave remote sensing observation can discover the change of microwave radiation fromthe seismogenic zone with very high sensitivity. Such observation may provide more important meaning for short-term earthquake forecast. Finally, based on the matter information theory, the feasibility and rationality of microwave remote sensing observation were discussed.

On a Robust Variogram Estimator

JIN Yi,PAN Mao,YAO Lingqing,MA Chong

2009, 45(6):  1033-1038. 

Asbtract ( )  

Related Articles | Metrics

Robust variogramis the basic guarantee of the effective spatial prediction using kriging methods. The existing variogram estimators behave poorly in practice. Some are not robust against the outliers in data; others are complex in algorithmin order to achieve robustness or hard to be used widely. The authors propose a simple variogramesti mator based on medianfiltering method, by taking into account correlation of neighbor hoodlags to improve its robustness against outliers. The robustness properties between the existing estimators and the proposed one are compared and analyzed. Experiments are carried out with data existing different types of outliers. The results show that the proposed variogram estimator is not only highly robust against outliers, but also easy to be used generally.

Driving Mechanism of Human Forces to Urban Ecological Water Requirementsin Bao’an, Shenzhen

MAO Xiaoling,TIAN Kun,LI Jingping,LI Tianhong,LIU Yongwei

2009, 45(6):  1046-1054. 

Asbtract ( )  

Related Articles | Metrics

The interruption of human with the urban ecosystems will change the land use structure dramatically and result in deterioration of environmental quality as well as the remarkable change of ecological water requirements. Based on the case study of Bao’an, Shenzhen, this paper presents the quantitative relationship between urban ecological water requirements (UEWR) and the characteristic index for land use structure (SI). The driving mechanism of human activitiesto the land use change and UEWR is studied by Partial Least Squares Regression model. The estimation results indicate the significant negative correlation between UEWR and SI. The human driving forces can explain 50 % ～90 % of the deviation of the land use, especially more than 90 % of the urban construction area and SI. The explanation ability of the same driving forces to the ecological water requirements are 60 % ～80 %. The coefficients of the regression model represent the weight of the driving forces, among which the population is of the most important contribution. Through the same human driving mechanism, the UEWR can be explained and predicted by the simple index of SI.

Transportation of mRNAin Dendrites

CHEN Li,TENG Junlin

2009, 45(6):  1075-1080. 

Asbtract ( )  

Related Articles | Metrics

The targeting of mRNAs to neuronal dendrites plays an important role for neuronal local protein synthesis and function. Neuronal mRNAs in granules such as RNP containing diverse components of controlling mRNA localization, stability, and translation, are transported by kinesin 1 along microtubules. An asymmetric distribution of mRNAs caused by the transport is essential to synaptic plasticity, learning, and memory.