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2011, Vol.28, No.4 Previous Issue    Next Issue
Research Articles
Calculation of K2(F2[C4×C4])
CHEN Hong, GAO Yu-Bin, TANG Guo-Ping
2011, 28 (4): 419-423.  DOI: 10.7523/j.issn.2095-6134.2011.4.001
Abstract ( 1126 ) PDF (KB) ( 3 )

First, we reduce the calculation of K2(F2[C4×C4]) to that of the relative K2-group K2(F2C4[t]/(t4),(t)) of the truncated polynomial ring F2C4[t]/(t4). Then we give a minimal generating set of K2(F2[C4×C4]) by subtle calculations of Dennis-Stein symbols. Finally we show that K2(F2[C4×C4])=C34C92.

The law of the iterated logarithm for random sums of a double random sequence
GAO Zhen-Long, HU Xiao-Yu
2011, 28 (4): 424-430.  DOI: 10.7523/j.issn.2095-6134.2011.4.002
Abstract ( 1294 ) PDF (KB) ( 1 )

We have obtained the law of the iterated logarithm for random sums of a double sequence of random variables {ξn,j; n≥1,j≥1}, where {ξn,j; n≥1,j≥1} are independent and for any fixed n, {ξn,j; j≥1} have the same distribution.

Structure of higher order Boolean networks
LI Zhi-Qiang, ZHAO Yin, CHENG Dai-Zhan
2011, 28 (4): 431-447.  DOI: 10.7523/j.issn.2095-6134.2011.4.003
Abstract ( 1309 ) PDF (KB) ( 3 )

The higher order Boolean (control) network is introduced and its topological structure is studied. Using semi-tensor product of matrices, its dynamics is converted into two algebraic forms, which are standard discrete-time dynamic systems. The one-to-one correspondence of the network dynamics and its first algebraic form is proved, and certain topological structures, including fixed points, cycles, and transient time, of higher order Boolean (control) networks are revealed. The relationship between the original system and its second algebraic form is also studied.

Theoretical study on CN-loss photodissociation of the C6H5CN+ ion in the low-lying electronic states
DONG Hua, CHEN Bo-Zhen, YU Shu-Yuan
2011, 28 (4): 448-456.  DOI: 10.7523/j.issn.2095-6134.2011.4.004
Abstract ( 957 ) PDF (KB) ( 4 )

CN-loss photodissociation of the C6H5CN+ ion has been studied within the C 2v symmetry using CASSCF and CASPT2 methods. The CASPT2//CASSCF dissociation potential energy curves (PECs) for the five lowest-lying states were calculated. By checking the relative energies, the fragmental geometries, and the charge and spin density populations of the asymptote products along the PECs, we conclude that the 12A1, 12B1, 12A2, 22B1, and 12B2 states of C6H5CN+ correlate with C6H+5 (X1A1) + CN (X2Σ+), C6H+5 (13B1) + CN (X2Σ+), C6H+5 (11A2) + CN (X2Σ+), C6H+5 (11B1) + CN (X2Σ+), and C6H+5 (X1A1) + CN (12Π), which are the first, second, third, fourth, and fifth dissociation limits, respectively.

Preparation and electrochemical properties of Li1+xV3O8-yFy synthesized by solid state reaction method at moderate-heating temperature
QIN Hong-Lian, TANG Zhi-Yuan, MA Li
2011, 28 (4): 457-461.  DOI: 10.7523/j.issn.2095-6134.2011.4.005
Abstract ( 1118 ) PDF (KB) ( 3 )

F--doped lithium vanadium oxides Li1+xV3O8-yFy was synthesized by a solid state reaction at moderate-heating temperature with Li2CO3 and V2O5 as raw materials. Crystal structures were characterized by XRD and electrochemical properties were studied by charge-discharge performance test, cyclic voltammetry test, and conductance test. The XRD results indicate that the products are pure without any impurities. Li1+xV3O8-yFy (y=0.1) shows the best electrochemical cyclability. The first discharge specific capacity is 252.08mAh/g, and the attractive specific capacity of 210.93 mAh/g is obtained after 25 cycles at 0.2c.

Calculations of Fraunhofer diffraction by irregularly shaped particles
ZHAO Jian-Qi
2011, 28 (4): 462-466.  DOI: 10.7523/j.issn.2095-6134.2011.4.006
Abstract ( 1104 ) PDF (KB) ( 4 )

Calculations of the Fraunhofer diffraction integrals for the translucent particles of irregular shape are discussed. Three kinds of new 1D contour integral for diffraction are derived by means of scalar Kirchhoff theory, and they are equivalent to each other and can get rid of the drawbacks of regional division in usual 2D surface integrals. Finally, analytical formula of diffraction integrals for the particles with arbitrarily polygonal projection are obtained.

Evaluation of the competitive levels and influence factors of equipment manufacturing industries in Northeast China
ZHANG Yue-Han, ZHANG Ping-Yu
2011, 28 (4): 467-474.  DOI: 10.7523/j.issn.2095-6134.2011.4.007
Abstract ( 1210 ) PDF (KB) ( 4 )

It is important to explicit the competitive levels and features of equipment manufacturing industries in Northeast China in the revitalization of the equipment manufacturing. We integrated shift-share method with the evaluation index of competitiveness, and evaluated the competitive levels, competitive structure, and influence factors of seven northeast equipment manufacturing industries. The results are as follows: 1) there are 4, 2, and 1 fast growth sections in Liaoning, Jilin, and Heilongjiang, respectively; 2) the standard, appliance, and transport equipment sections are at significant growing and competitive advantages; 3) the competitive structure features are market-technology, efficiency-structure, and structure-innovation; 4) the new influence factors such as senior human resource, technological innovation, and FDI are not significant.

Interactive software for three-dimensional Q tomography and its application to seismic data processing
FAN Ji-Chang, LIU Ming-Jun, HAI Yan
2011, 28 (4): 475-480.  DOI: 10.7523/j.issn.2095-6134.2011.4.008
Abstract ( 1485 ) PDF (KB) ( 2 )

Q-value structure of the crust is of great significance for understanding of non-elastic nature of crustal structure, thermal activity, crustal inhomogeneity, and fault distribution. We present an interactive software for three-dimensional Q tomography based on absorption characteristic time t*. Amplitude spectra of seismic data (P-wave and S-wave) can then be calculated quickly and easily, absorption characteristic times can be obtained through fitting amplitude spectra, and three-dimensional Q structure can be obtained by using the Q tomography method and t* data. The real example shows that the method and software are effective and feasible.

Identification and functional study of tumor suppressor Caliban interacting proteins
WANG Zhe, ZHANG Jie, ZHAO Yu-Liang, BI Xiao-Lin
2011, 28 (4): 481-488.  DOI: 10.7523/j.issn.2095-6134.2011.4.009
Abstract ( 1147 ) PDF (KB) ( 1 )

Caliban is a tumor suppressor. To understand its inherent mechanisms, we screened Caliban interacting proteins using the yeast two-hybrid system. We found four new Caliban interacting proteins, Bip2, Uba2, RpS27A, and CG7182. Moreover, over-expression of transcriptional factor Bip2 suppresses transcription of p 53. The tumor suppression function of p53 could be regulated through new mechanisms involving Bip2 and Caliban.

Systematic model and errors analysis for distributed satellites SAR system based on three-dimensional reconstruction model
Hu Ji-Wei, HONG Jun
2011, 28 (4): 489-497.  DOI: 10.7523/j.issn.2095-6134.2011.4.010
Abstract ( 1129 ) PDF (KB) ( 4 )

We analyse the systematic model and working principle of distributed satellites SAR system based on three-dimensional reconstruction principle of InSAR system and present a complete closed-form solution to the three-dimensional geo-location of targets. Meanwhile we analyse the main error sources, baseline error and interferometric phase error, which influence the precision of digital elevation models (DEM) acquisition. Finally, simulations are made for analyses of the characteristics of baseline error and interferometric phase error, which provides a basis for calibration and correction of systematic parameters.

Modified RMA based on range sub-blocks in range-Doppler domain
XU Hai-Sheng, SONG Hong-Jun, HUA Bin, YUAN Zhi-Hui
2011, 28 (4): 498-504.  DOI: 10.7523/j.issn.2095-6134.2011.4.011
Abstract ( 1585 ) PDF (KB) ( 3 )

On the basis of our study on SAR imaging algorithm in 2D frequency domain, we propose a modified range migration algorithm (RMA) using range sub-blocks in range-Doppler domain (RDB-RMA), and make a comparison between our proposed algorithm and other two algorithms, approximate RMA and scaled inverse Fourier transformation algorithm (SIFTA). The simulation data show that RDB-RMA is better in focusing capabilitity than the other two algorithms, when the swath is very wide and the range migration is very large. By comparing these algorithms, we conclude that RDB-RMA is better in computing efficiency than SIFTA. Finally, an experiment carried out on measured data confirms feasibility of the proposed algorithm.

Technology of automatic data discrimination based on CLIPS expert system
HE Yu-Feng, ZHAO Guang-Heng, LV Cong-Min, GUO Li-Li
2011, 28 (4): 505-513.  DOI: 10.7523/j.issn.2095-6134.2011.4.012
Abstract ( 1106 ) PDF (KB) ( 2 )

Considering the mass data and complex criterions of payload telemetry, we propose a technology of automatic discrimination for payload telemetry data based on C language integrated production system (CLIPS). This technology realizes not only the descriptions of complex discrimination rules by adopting the expert system language CLIPS but also the dynamic discrimination of telemetry data varying with the state of payloads by introducing finite state machine. Besides, we design the auxiliary learning algorithm of discrimination knowledge by mining rules from frequent patterns and improve the speed of discrimination by using reasoning mechanism of CLIPS. Thus this technology can meet the requirement of data discrimination for payload system test and flight control, and dramatically improves the efficiency and veracity of discrimination.It has been successfully applied to some satellite projects.

Adaptive compensation control of free-floating space robot based on fuzzy neural network
ZHANG Wen-Hui, QI Nai-Ming, Ma Jing, XIAO A-Yang
2011, 28 (4): 514-521.  DOI: 10.7523/j.issn.2095-6134.2011.4.013
Abstract ( 1364 ) PDF (KB) ( 2 )

Considering trajectory tracking of free-floating space robot with uncertainties and friction blind section non-linearity, we propose an adaptive fuzzy CMAC compensation control algorithm. The control scheme uses fuzzy neural network to establish modeling online, and imports GL matrix and multiplication operator "." into neural network to distinguish parameters of system and friction blind section non-linearity. The control scheme can guarantee the stability of closed loop system and the asymptotic convergence of tracking errors. Neural network approach errors and outside disturbance can be eliminated by sliding model controller. Based on a standard Lyapunov theorem, we prove that all signals in the closed-loop are bounded. The simulation results show that the controller can achieve high control precision and meet the requirement of real time.

Cooperation diversity-aware routing metric and cooperative routing protocol for 802.11s-based wireless Mesh networks
HE Wei-Qing, YANG Shou-Bao, TENG Da, HU Yun
2011, 28 (4): 522-530.  DOI: 10.7523/j.issn.2095-6134.2011.4.014
Abstract ( 1036 ) PDF (KB) ( 3 )

A cooperation diversity-aware routing metric for 802.11s-based wireless Mesh networks(WMNs) is proposed. Furthermore, a cooperation diversity-aware routing protocol (CDARP) and a cooperative MAC protocol (CMAC) are proposed, and both the protocals are adapted to the characteristic of WMNs. By building up virtual nodes and calculating the routing metric for virtual links, CDARP-CMAC can select the most reasonable path to cooperatively transmit packets. The simulation results show that, compared to the traditional cooperation scheme, CDARP-CMAC improves the good put by 5%~13% and reduces the drop rate by 5%~10%.

Parallelization and performance optimization of video feature extractions on multi-core systems
ZHANG Qi, CHEN Yu-Rong, LI Jian-Guo, HU Yun, XU Yin-Long
2011, 28 (4): 531-547.  DOI: 10.7523/j.issn.2095-6134.2011.4.015
Abstract ( 1515 ) PDF (KB) ( 3 )

The low-level video feature extractions are the most time-consuming components in content-based video information retrieval systems. In this paper we study parallelization and performance optimization methods of four video feature extractions on multi-core systems. Experiments show that the processing speeds of these programs are 17 times the original processing speed on average when eight cores are used. Besides, detailed performance analysis helps us find bottlenecks and suggest ways to further improve multi-core systems performance in future.

Brief Report
Brief Report Number ω(n) of distinct prime factors for a kind of odd perfect number
ZHANG Si-Bao, DENG Yong
2011, 28 (4): 548-550.  DOI: 10.7523/j.issn.2095-6134.2011.4.016
Abstract ( 1005 ) PDF (KB) ( 3 )

The existence of odd perfect numbers is a well-known open problem in number theory. We prove that if n is an odd perfect number which is relatively prime to 3, then ω(n)≥16, where ω(n) is the number of distinct prime factors of n.

Isolation and expression of heavy metal ATPase in Brassica juncea L.
ZHANG Yu-Xiu, ZHANG Yuan-Ya, CHAI Tuan-Yao
2011, 28 (4): 551-555.  DOI: 10.7523/j.issn.2095-6134.2011.4.017
Abstract ( 1489 ) PDF (KB) ( 3 )

Brassica juncea L. is a Zn/Cd tolerance plant, and the gene expression of heavy metal ATPase (HMA) has not been reported. In the present work, two cDNA fragments of BjHMA, BjHMA 3 and BjHMA 4 , were isolated from B. juncea seedling. Real-time quantitative PCR analysis revealed that both BjHMA 3 and BjHMA 4 were constitutively expressed in all tissue and preferentially in root. The mRNA profile of BjHMA 3 or BjHMA 4 was the lowest in leaf while the expressions were strongly enhanced by Zn or Cd stress, indicating that BjHMA played important roles in growth and in heavy metal homeostasis and tolerance in plant.

Three-dimensional flight path planning using electric potential theory with improved threat model
LIU Li-Feng, ZHANG Shu-Qing
2011, 28 (4): 556-561.  DOI: 10.7523/j.issn.2095-6134.2011.4.018
Abstract ( 1132 ) PDF (KB) ( 3 )

An improved threat model of potential field theory is used to plan practical 3D track. Terrain, radar, and fire threats are classified and analyzed, and formulas are deduced. Search field is limited within a rectangle zone including the start point and destination, which reduces complexity of calculation and ensures convergence to destination. The flight line is confined by using the gradient restriction smoothing algorithm and curvature limit smoothing algorithm, which is suitable for aircraft mobility.