Journal of University of Chinese Academy of Sciences

An electric field model for orientation field estimation in fingerprint images

Fan ling-ling, Wang shu-guang, Guo tian-de

2008, 25 (4): 433-438. DOI: 10.7523/j.issn.2095-6134.2008.4.001

An electric field model based on baseline and core points is proposed to estimate fingerprint orientation field. Orientation field firstly emerged in baseline and core area. Orientation field near baseline is parallel to baseline which is caused by baseline. Orientation field near core point is changeable which is influenced by core point. Then fingerprint orientation field outspreads. At last, orientation field converges at delta point. This model can explain well why core and delta points exist in pairs in fingerprint images. Experimental results in NIST-4 show that our model can estimate fingerprint orientation field fairly accurately.

Researching on warrant-bond

Hua hong-yu, Cheng xi-jun

2008, 25 (4): 439-444. DOI: 10.7523/j.issn.2095-6134.2008.4.002

Abstract ( 849 ) PDF (KB) ( 0 )

In this paper, we discuss the price of warrants in the warrant-bonds according to the neutral-risky pricing principle. This is a simple Bermudan warrants. Considering a complete market, in accordance with the principle of maximizing the return and the martingale pricing principle, we get a theoretical price of this warrant. At last, we briefly discuss its conversion strategy.

Optimization of data collecting solution for Web usage mining

Wang zheng, Zhang jun-yu

2008, 25 (4): 445-451. DOI: 10.7523/j.issn.2095-6134.2008.4.003

Abstract ( 1271 ) PDF (KB) ( 0 )

This paper focuses on optimization of data collecting solution for Web usage mining in order to improve operating efficiency of Web usage mining systems. Some strategies are introduced, like reducing redundancy, extending functions of elements to be collected, differentiating the submission based on elements classifying, advancing data preprocessing at client sides and so on. With these strategies, the efficiency of data storing, resources balancing, data analyzing and transferring are significantly improved.

Conformal minimal immersions of S² in CPⁿ

Chen hong-xia, Jiao xiao-xiang

2008, 25 (4): 452-459. DOI: 10.7523/j.issn.2095-6134.2008.4.004

Abstract ( 944 ) PDF (KB) ( 0 )

In this paper, conformal minimal 2-sphere immersed in a complex projective space are studied by applying Lie theory, moving frame and harmonic sequence. First, we use a different way from Bolton to prove that a holomorphic curve from S² into CPⁿis uniquely determined by its induced metric, up to a rigid motion. Secondly, via conformal minimal immersions of constant curvature from S²into CPⁿ, we can construct new minimal immersions of S²in G_2,n+1 with constant curvature. Finally, if φ is a totally real conformal minimal 2-sphere of constant curvature immersed in a complex projective space, then we can find the explicit isometry transform ｇ such that ｇφ lies in RPⁿCP^n.

Truncated error estimate on sampling theorem

Hu yi

2008, 25 (4): 460-466. DOI: 10.7523/j.issn.2095-6134.2008.4.005

Abstract ( 1059 ) PDF (KB) ( 0 )

In this paper we discuss the truncated error estimate on Shannon sampling theorem of bandlimited functions. We mainly focus on error of pointwise type, uniform type and integral type. In pointwise type, we use the method of calcuating Dirichlet kernel and obtain the order O(1/N); in uniform and integral type, by calculating the decaying condition imposed on the function, we can get the uniform and integral estimate.

Applications of electro-optical pod in airborne and airdrop system

Fan Lei Xiang Yang

2008, 25 (4): 467-470. DOI: 10.7523/j.issn.2095-6134.2008.4.006

Abstract ( 919 ) PDF (KB) ( 0 )

The advanced electro-optical pod technology has been discussed. The method of combining that with horizontal airdrop principle is put forward, the mathematics model for that has been founded, and the relative error is analyzed, which supplies theory basis. This method has great value in use and strong application in future.

The Spatial Structure and Evolution of the of the Education Quality of Population in China

QIN Xian-hong YU Xiao-gan DUAN Xue-jun LI Hui TIAN Fang

2008, 25 (4): 471-478. DOI: 10.7523/j.issn.2095-6134.2008.4.007

Abstract ( 1377 ) PDF (KB) ( 0 )

With the development of social economy, the education quality of population has a stronger impact on the economic growth in China. As a result, it is of great significance to study the spatial structure and evolution of it. This paper discusses this problem from the angle of average school year of population in the 31 provinces; and compares it with the average GDP. The results show that: (1) Regional education quality of population is higher in northeast of china, and lower in southwest; three steps from high to middle to low can be found from northeast to southwest. (2) In the 23 years, education quality of people has been greatly improved; but the degrees are different in different provinces. The changing extent is related to the initial level in the first stage (from 1982 to 1997), and is related to the economic level in the second stage (from 1997 to 2005). (3)The relation between the education quality of population and economic development can be classified into four types: harmony-developed, education quality-lagged, economy-lagged, and both-lagged.

Effect of long-term fertilization on microbial community in a Chinese arable Mollisol

BAI Zhen ZHANG Ming LIU Ning ZHANG Xu-dong

2008, 25 (4): 479-486. DOI: 10.7523/j.issn.2095-6134.2008.4.008

Abstract ( 1215 ) PDF (KB) ( 0 )

The soil samples were taken from different treatments including CK, P, NP, NPK, MP（manure + P）, MNP（manure + NP）, and MNPK（manure + NPK） in a Mollisol long-term fertilizer experimental site. Basic soil properties, phospholipid fatty acid（PLFA）, acid（alkaline） phosphatase activities and soil microbial biomass C or N（SMB-C or N） were measured. The results showed that 26 years of the combined application of manure and chemical fertilizers had significantly increased the amounts of organic matter（OM）, total nitrogen（TN）, available phosphorus（AP）, alkali-hydrolysable nitrogen（AN）, and readily available potassium（RAK）. Furthermore, the SMB-C, SMB-C/organic matter（OM） ratio, acid（alkaline） phosphatase activities and PLFA content of different microbial communities in manure treatments were higher than those of CK or chemical fertilizer treatments. Long-term application of NPK treatment obviously inhibited microbial activity, while single P or NP treatment had little effect on this arable Mollisol microbial community. Monounsaturated fatty acids-to-normal saturated fatty acids（MONO/NSAT） ratios in manure treatments were significantly higher than those of chemical fertilizer treatments or CK, while terminally branched saturated fatty acids-to-monounsaturated fatty acids（TBSAT/MONO） ratios exhibited extremely significant negative correlation with MONO/NSAT ratios and changed in a totally opposite way. Principal components analysis of PLFA showed that manure and chemical fertilizers affected microbial communities’ structure in a very different way. The loading values for the individual PLFA showed that fungal 18:26,9 was significantly affected by chemical fertilizer treatments, while G+ i15:0, i17:0, i16:0 were liable to be affected by manure amendment.

The stability and failure mode study on the tuunnel-anchorage rock masses

Hu Bo Zeng Qian-bang Peng Yun-dong Liu Bo Zhao Hai-bin

2008, 25 (4): 487-492. DOI: 10.7523/j.issn.2095-6134.2008.4.009

Abstract ( 1364 ) PDF (KB) ( 0 )

The study on stability and failure mode of anchorage rock masses is the foundation of the ultimate bearing capacity evaluation. The integrations of numerical simulation and in situ scale model test are believed to be an effective and convenient method to achieve our study purpose. As an example, this method is carried out in stability and failure mode analysis of Balinghe super bridge. According to the FLAC3D numerical analysis, the stress field and displacement field show subsection characters under designed load. There are some stress concentration and excessive displacement zones at the corners of the structure and the upper part of the hollow anchorage room. There is no coherent plastic zone in the anchorage-rock mass system. Some partial failure zones mainly appear in five areas including the upper-right of the anchorage. According to the overload test, the failure does not simply happen on the boundary of the anchorage and rock masses, but holding the surrounding rock appears as plug style tensile-shear complex failure. The numerical calculated results coincide well with the in-situ scale model test. The plastic and prominent deformation zones in the rock mass should be paid more attention during design and construction.

Analysis of land use/cover change and soil erosion in Sanjiang plain during the past 50 years

WANG Wen-Juan ZHANG Shu-Wen LI Ying BU Kun

2008, 25 (4): 493-502. DOI: 10.7523/j.issn.2095-6134.2008.4.010

Abstract ( 1167 ) PDF (KB) ( 0 )

Based on TM,MSS and relief map,with expert knowledge,the information of land use/cover change in 1954,1976,1986 and 2000 were obtained in Sanjiang plain; At the same time, using GIS and USLE, according to the actual situation in Sangjing plain, by choosing the reasonable methods to calculate R,K, LS, C,P factors in the USLE, the soil erosion of Sanjiang plain in 1954,1976,1986 and 2000 was evaluated. Then with consideration of the geomorphologic unit and the soil erosion intensity grading map of 2000,Sanjiang plain was divided into 7 different regions.They were northern hejiang plain region,southeast muling-xingkai plain region,southwest woken river-valley plain region,west qingheishan low mountain and hill region,east wandashan low mountain and hill region,southwest aerhawoshan low mountain and hill region,and south laoyeling-kenate-taipingling low mountain and hill region.For the different regions,their LUCC pattern and soil erosion state were quantitatively analyzed and evaluated during the past 50 years.By these analysis,the trend and actuality of LUCC and soil erosion were acquired.Then we can provide some scientific suggestion for the land use and erosion control.So we expect these reasonable suggestion can help the management and decision-makers for the sustainable development in this region.

Soil moisture spectral analysis and its spectral model

LIU Huan-Jun ZHANG Bai SONG Kai-Shan WANG Zong-Ming LI Wei-Dong YANG Fei

2008, 25 (4): 503-509. DOI: 10.7523/j.issn.2095-6134.2008.4.011

Abstract ( 1378 ) PDF (KB) ( 0 )

To improve the method for soil moisture monitoring, uncover the mechanism of moisture effects on soil spectral reflectance, and provide theoretical information for other soil properties’ spectral analysis and remote sensing monitoring, Black soil samples from Dehui city, Jilin province, China, their field and laboratory reflectance were taken, and derivate, continuum removal and statistical methods were used to analyze soil moisture spectral characteristics and build soil moisture spectral models. The results are as follows: there are five absorption vales on soil spectral reflectance in the region 400-2500 nm, the vales grow with increasing soil moisture; however, the absorption vales’ areas of crop residue in the spectral range of the first two vales of soil can be ignored, which can be used to determine whether soil is covered with residue; stubble field shows the characteristics of soil, the five spectral vales are significant, but for the effect of stubble, the minimum value of the second vale moves to longer wavelength, and the proportion of the right side decreases significantly, which indicates whether the field is furrowed or not; so soil remote sensing should be conducted after field furrowed; the correlation between soil moisture at the depth 0-5 cm and spectral data is more remarkable than that at the depth 5-10 cm; the relationship between soil moisture and reflectance is exponent or linear, which should be considered when other soil properties are remotely sensed; soil moisture spectral models are very stable and accurate, can be used for quickly soil moisture monitoring.

Overexpression of BjPCS1 gene from Brassica juncea enhances the heavy metal tolerance in transgenic tobacco

Wei Wei, Han Lu, Guan Zi-Qiu, Chai Tuan-Yao

2008, 25 (4): 510-517. DOI: 10.7523/j.issn.2095-6134.2008.4.012

Abstract ( 1597 ) PDF (KB) ( 0 )

GSH is the substrate that synthesizes PC, which chelates the heavy metals. Heavy metal-PC chelatins are subsequently transported from the cytosol to the vacuole and heavy metal detoxification is thus achieved. A plant-expressed plasmid with PC synthesase from Brassica juncea (BjPCS1) was constructed and transferred into tobacco. PCR and Northern blot indicated that BjPCS1 was integrated into the genome of tobacco and functioned properly. Physiological responses of the transformant to three heavy metals (200mmol/L CdCl2、400mmol/L ZnCl2、200mmol/L NiCl2) treatment, reflected by relative electronic conductivity (Rc/Rc’), chlorophyll content (Chla+b), content of dissolvent suga and MDA content, were better than those in the control plants. These results indicated that BjPCS1 transformation could improve the heavy metal tolerance of the transgenic tobaccos, especially Cd tolerance. Furthermore, the seedlings of offspring from BjPCS1 positive plants were tested for resistance to Cd. The results confirmed that the expression of BjPCS1 could enhance Cd tolerance of transgenic tobaccos. As its an important role in transgenic plants, BjPCS1 gene can work as a significant gene tool in the phytoremediation of heavy metal pollution.

Scratch Removal for the Old Film Based on the Spatial Features

DU Kun, ZOU Mou-Yan

2008, 25 (4): 518-523. DOI: 10.7523/j.issn.2095-6134.2008.4.013

Abstract ( 1336 ) PDF (KB) ( 0 )

A new method for scratch removal based on spatial features is proposed. The method meets with good results with lower complexity because it performs on the projective array of the degraded image in the vertical direction. The method proves capable of removing scratches in heavily-degraded film sequences.

Emulation of Space Communications System and Research on QoS Performance Measurement

LI Biao, ZHANG Can, , FU Qian-cheng

2008, 25 (4): 530-537. DOI: 10.7523/j.issn.2095-6134.2008.4.015

Abstract ( 943 ) PDF (KB) ( 0 )

Because of its inherent characteristics, space communications link raises new requirements and challenges on the QoS (Quality of Services) of space communications. This paper suggests architecture for the emulation of space communication system and achieves its implementation with STK (Satellite Toolkit). Meanwhile, we develop QoS performance measurement software for space communications system and analyze the QoS performance of proposed architecture.

The function isolation mechanism in secure operating system

Gong Yu-chang, Tang Ling, Zhang Ye, Jia Yong-quan

2008, 25 (4): 538-548. DOI: 10.7523/j.issn.2095-6134.2008.4.016

Abstract ( 1160 ) PDF (KB) ( 23 )

Considering the limitations of current space isolation technique, a new security mechanism adopting function isolation is proposed in this paper. With the mechanism more delicate granularity of function can be used and different execution domains corresponding to different function requests may be isolated each other, so the safety of operating system can be improved. In the paper the principle and algorithm for function division are introduced in detail, and two kinds of isolating mechanisms PFI and ASFI are presented. Experiment results show that the overhead of function isolation wouldn’t reduce the system efficiency notably.

Researches on the high-speed divider in the PLL frequency synthesizer

Yuan Quan, Yang Hai-gang, Dong Fang-yuan, Yin Tao

2008, 25 (4): 549-553. DOI: 10.7523/j.issn.2095-6134.2008.4.017

Abstract ( 1264 ) PDF (KB) ( 0 )

In this paper, the design of the high-speed divider in the PLL frequency synthesizer is investigated. The characteristics of circuits concerning speed and power are compared between the synchronous divider and the asynchronous divider. Considering the different demands for the divide-by-2 circuits in the phase-switching asynchronous divider, several different circuits topology of the divide-by-2 circuits are presented. And the charge sharing problem of the divide-by-2 circuit in a reference paper is solved in this paper. According to the simulation results, the highest working frequency of the first and the improved second divider-by-2 circuits is 3.3GHz, and the current consumption is 1.9mA.

G¹continuity blending between bicubic non-uniform B-spline surfaces with stream curve and surface

LI Xiu-Juan LIAO Wen-He LIU Hao He Gang

2008, 25 (4): 554-559. DOI: 10.7523/j.issn.2095-6134.2008.4.018

Abstract ( 1327 ) PDF (KB) ( 0 )

Non-uniform subdivision is introduced in streamline modeling. Expressions and calculations of non-uniform subdivision are given on Gaussian sphere. The generation approaches of stream curve and surface based on non-uniform subdivision are provided. G¹ Continuity conditions between bicubic B-spline surface and stream curve and surface are studied. Furthermore, a construction means to blend bicubic B-spline surfaces with stream curve and surface is presented.

Research and implementation of a tool path optimization method based on mesh uniformization

LIU Yi, CONG Shuang

2008, 25 (4): 560-568. DOI: 10.7523/j.issn.2095-6134.2008.4.019

Abstract ( 1295 ) PDF (KB) ( 0 )

In machining 3-axis sculptured surface, the quality of machined surface has a close connection with the quality of tool path. When the tool path is generated by using current CAD/CAM integrated software and a tolerance of 0.01mm is set as usual, the machined surface would probably have such disadvantages as surface dents, poor roughness. To solve this problem, a tool path optimization method based on mesh uniformization is proposed in this paper. Based on the original tool path generated by Cimatron, We construct the dominant contour and modify the irregular points to reduce the variety of the inclination degree between the succeeding paths, then identify the smooth continuous line segments along the same path and fit the smooth continuous line segments by using piecewise 3-order spline curve to improve the smoothness of curve along the same path. Simulation and actual machining experiment verify that the proposed method can eliminate the dents on the surface and improve the final machined surface quality effectively.

Studies on the chemical constituents and bioactivities of five schisandra medicinal species and elsholtzia bodinieri

LI Rong-Tao, SUN Han-Dong

2008, 25 (4): 569-575. DOI: 10.7523/j.issn.2095-6134.2008.4.020

Abstract ( 1510 ) PDF (KB) ( 2 )

The chemical constituents and bioactivities of six medicinal plants have been studied. In the study, one hundred and one compounds, including twenty-six new compounds were isolated. Among these compounds, sixteen unique highly oxidized nortriterpenoids, belonging to an unprecedented new nortriterpenoid skeleton with a biosynthetically modified eight-membered ring, and unusual nortriterpenoids or bisnortriterpenoid skeletons, have been isolated from three Schisandra species. Interestingly, to date, no naturally occurring triterpenoids have been found to have such a highly modified oxidized norcycloartane skeleton.
The bioactivities of compounds isolated from the genus Schisandra have been tested, including anti-HIV-1, anti-inflammatory, and cytotoxities against C8166, MT-4 and K562 cells activities. Gomisin G and micrandilactone C were found to show promising anti-HIV-1 activity and the selectivity index were 174.08 and >25.94, respectively.

Current Issue