Table of Content

20 July 2008, Volume 44 Issue 4

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Stylized Rendering of 3D Models Based on Feature Strokes

JING Hao,ZHOU Bingfeng

2008, 44(4):  543-548. 

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A method for generating stylized rendering image from triangle mesh models is presented based on feature strokes. First, the segmentation standard function and energy function based on radial curvature is defined. Second the feature vertices on 3D model are segmented automatically by graph cuts algorithm with energy minimization. Feature vertices are connected to form feature strokes. Texture mapping technique is used to produce stylized image. There are two different texture coordinates computation strategies which can produce different styles. The styles of feature strokes can be controlled easily.

Penetration-Depth Anisotropy in MgB₂: Two-Band Ginzburg-Landau Theory

LIU Minxia

2008, 44(4):  507-510. 

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Penetration-depth in two-band superconductors MgB₂ is calculated by using two-band GL theory. It can be found that the ratio (γ_λ) of penetration-depth in c direction and in ab plane enhances with the increase of temperature. With the proper parameters, the theoretical result is in agreement with the experimental result at high temperature. γ_λ in the dirty limit is also discussed.

An Iterative Carrier Frequency Estimation Algorithm

LUO Wu,LIU An,LIANG Qinglin

2008, 44(4):  554-558. 

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An iterative data-aided algorithm based on maximum likelihood (ML) for carrier frequency estimation under low signal-to-noise ratio (SNR) environment is proposed. Simulation results show that it can achieve about 3dB lower SNR threshold when compared with M&M algorithm. Its estimation range is large, about 40% of the symbol rate and its accuracy is very close to FFT-based maximum likelihood frequency estimation algorithm and the Cramer-Rao lower bound (CRLB). Moreover, the simplified estimator based on proposed algorithm has both lower threshold and less computational complexity when compared with iterative linear prediction (ILP) algorithm.

An Age Encoding Based Bloom Filter Algorithm for Load-Store Queue Energy Reduction

ZHAO Yulai,TONG Dong,CHENG Xu

2008, 44(4):  559-565. 

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The load-store order violations and load-load order violations are considered in multithreaded or multiprocessor systems, and the counter-based bloom filter algorithm is improved by eliminating false positives through age encoding. The filtering ratio is improved by over 5% with no impacts on pipeline timing or performance.

Wind Loading on Plane Roof of a Large Hangar

GU Zhifu,YANG Letian,CHEN Qingsong,LI Yan,PEI Yongzhong

2008, 44(4):  501-506. 

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Wind loading on the roof of a large hangar was investigated by wind tunnel simulation. Results show that under certain wind directions a conical vortex or a pair of conical vortex appears above the roof. The strong peak local negative pressure induced by the conical vortex is the main reason for the destruction on the roof and the parapet may reduce the pressure on the roof. The characteristic of time-mean and fluctuating pressure and their relationship were analyzed. The large difference between the value of fluctuating pressure obtained by the tests and that calculated by the code were discussed.

Anticancer Activity on Prostate Cancer of the Extracts of Prescription of TCM 921

LI Jiangbin,LI Hongyan,ZHANG Zhihong,CHEN Xiaoguang,YE Zuguang,GUO Yinglu

2008, 44(4):  511-516. 

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In order to investigate the inhibition of the extracts of prescription of 921 on prostate cancer cell proliferation in vitro and tumor growth in vivo, the authors used the methods as follows: SRB assay was applied to examine the anti-proliferation of the extracts of prescription of 921 in vitro both on human cancer cell DU-145, PC-3m, EJ and mice prostate cancer TRAMP-C2. The experimental implanted tumor mice model Hepatoma (H22), Sarcoma (S180), Prostate cancer (TRAMP-C2) and tumor nude mice model Prostate cancer (PC-3M) were used to evaluate its anti-tumor activity in vivo. Furthermore, the enhance therapeutic effect was also observed when combined with cyclophosphamide (CTX) on S180. The results were 1) the extracts of prescription of 921 showed proliferation inhibitory activities on DU-145, PC-3M, EJ and TRAMP-C2 cell lines; 2) it inhibited mice H22, S180, TRAMP-C2 and naked mice PC-3M when administered i.g. at 3.6～14.3 g/(kg?day) for 9 days. The extracts of prescription of 921 enhanced CTX's therapeutic effect and didn't enhance its toxicity. In summary, the extracts of prescription of 921 showed inhibitory activity on the growth of prostate cancer.

A High-Order Temperature Compensated CMOS Bandgap Reference

CHEN Jianghua,NI Xuewen,MO Bangxian

2008, 44(4):  517-521. 

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A high-order temperature compensated bandgap reference (BGR) based on CSMC 0.5-μm 2P3M n-well mixed signal CMOS process is presented. This novel proposed CMOS bandgap reference takes advantage of both a Buck's voltage transfer cell and a temperature independent current, to provide a high-order temperature compensation of the base-emitter voltage V_BE. Cascode structures are also introduced in this CMOS bandgap reference to improve the power supply rejection ratio (PSRR). This circuit achieves 5.6ppm/℃ of temperature coefficient with temperature range from -20 to 100℃ at 5V power supply. The variation in the output voltage of the bandgap reference is 0.4mV when power supply changes from 4V to 6V.

A Novel Parallel VLSI Architecture for H.264/AVC Scalar Quantization

PENG Chungan,YU Dunshan,CAO Xixin,SHENG Shimin

2008, 44(4):  522-526. 

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52-level scalar quantization technology plays an important role in H.264/AVC. A novel parallel VLSI architecture is proposed for its hardware implementation, in which the 4×4 matrix multiplications is replaced by 16 unsigned compressed shift-adder-trees using partial CSD code scheme, switching reference wirings substitutes for look-up operation, and division is also avoided effectively, and no ROM or RAM is adopted in the overall quantizer. It can fulfill all the quantization calculations for all H.264 hybrid transform in 4×4 block parallelism. Its block throughput can reach 121.6MHz, which can meet the real-time requirement for 4096×2304@120Hz (119.43936M/s) video compression. Compared with the conventional architecture, 38% cost and 30% power are saved. Considering speed and cost optimization, this architecture is very suitable for pipeline acceleration, and it is a useful IP for high resolution H.264 encoder VLSI realization.

A Practical Hierarchical Key Management Scheme Based on One-Way Hash Function

HAN Xinhui,LONG Qin,SI Duanfeng,ZHUGE Jianwei,YE Zhiyuan

2008, 44(4):  527-536. 

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A formal definition and analysis on the hierarchical key management is presented for permission management and access control problem in the role hierarchy. Based on one-way hash function, a practical hierarchical key management scheme is proposed. This scheme allows the role to select its master key by itself, and constructs the hierarchical permission relationship with secure hash function and public parameters. The process of key generation and derivation is simple and effective in this proposed scheme, which satisfies the security requirement of the hierarchical permission management. Compared with other present schemes, the new scheme optimizes the efficiency of key derivation and storage overhead. The dynamic access control of hierarchical role can be adapted in this new scheme.

A Malicious Behavior Analysis Method Based on Program Semantic

LI Jiajing,LIANG Zhiyin,WEI Tao,MAO Jian

2008, 44(4):  537-542. 

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A semantic based method is presented to analyze malicious behavior in software, with more precise description of function call based attacks, and flow sensitive, context sensitive and path sensitive inter-procedure analysis ability. Experiments on malicious and benign programs show that it is effective to identify malicious behavior in software.

Absolute Frequency Measurements of the Clock Transition5s²¹S₀-5s5p³P₀ in Singly Ionized Indium

WANG Yanhui,LIU Tao,A.Stejskal,ZHAO Yanning,R. Dumke,ZHANG Jie,LU Zehuang,WANG Lijun,DONG Taiqian

2008, 44(4):  549-553. 

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The authors report on the current status of the optical frequency standard based on a single ¹¹⁵In⁺ ion. A single Indium ion is trapped in a Paul-Straubel type trap and cooled by sideband cooling to its lowest vibrational states. To interrogate the 5s²¹S₀-5s5p³P₀ clock transition with high accuracy, the authors demonstrate a Hz-level level laser system resonant to this transition. The Absolute frequency measurement is performed with the help of a femtosecond laser referenced to a commercial cesium atomic clock. 20 sessions measurements are achieved. The relative fractional uncertainty is 5.0×10^-14.

Preservation and Stable Carbon-Oxygen Isotopes of Late Devonian Brachiopods in South China

SUN Yuanyuan,LIU Jianbo,MA Xueping

2008, 44(4):  566-578. 

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Two basic shell structures are recognized based on study of brachiopods across the Frasnian-Famennian (F/F) boundary (Upper Devonian) in Hunan Province, South China, which are characterized respectively by the presence and absence of a tertiary columnar layer. For excluding poorly preserved shells, a shell alteration index is suggested to estimate the state of preservation of brachiopod shells through examination under cathodoluminescence and scanning electron microscopes. This study shows brachiopod taxa (e.g., Atrypida) with both secondary and tertiary layers have better state of shell preservation and more concentrate carbon and oxygen isotopic distribution than those only with secondary layers and consequently, are more reliable material to determine stable isotopic composition of the Devonian seawater.

Dust Concentration and Micrometeorological Elements in Different Dust Storm Events

ZHU Hao,ZHANG Hongsheng,PENG Yan,CHEN Jiayi,Soon-Ung Park

2008, 44(4):  579-584. 

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Based on data from the dust storm monitoring station over Hunshandake Desert Area, Inner Mongolia, the maximum values of micrometeorological variables, turbulent fluxes and dust concentration in the surface layer are compared for eight dust events in the spring of 2004, and the characteristics of micrometeorology and radiation components in the strongest dust storm event in March 27-28 are analyzed. The results show that temperature differences in the surface layer, net radiation and sensible heat fluxes all decrease during daytime, and the strength of temperature inversion weakens at night. When dust events occur, momentum fluxes increase. It is found that both mechanical turbulence and thermodynamic turbulence play important roles in local dust rising and vertical dust transport over source regions. During the passage of the strongest dust storm event in March 27-28, dust concentration, wind speed and vertical shear of wind velocity increase rapidly, together with changes of wind direction. At the strengthening stage of the dust storm, temperature falls by about 7℃, and there is a peak value of specific humidity. Both the net radiation and sensible heat fluxes become negative. When dust concentration reaches its maximum, the net radiation rises to zero, which reflects the heating effect of dust aerosol during nighttime.

Numerical Simulations of the Wind Environment around Buildings Affected by a Small Green Belt

KE Yongdong,SANG Jianguo

2008, 44(4):  585-591. 

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The concept of leaf area index(LAI) is introduced into a urban street layer(USL) model to simulate the windbreak effects of a small-sized green belt on the wind environment in USL. Comparison between simulated results and the field observations shows that the model can be reasonably used to simulate the dynamical sheltering effects of the windbreak. In the research the model is used to study the wind environment in the vicinity of a tall building affected by a small-sized green belt. The numerical experiments show that the green belts exert significant effects on the pedestrian level wind field caused by tall buildings and a well-designed small-sized green belt may well improve the wind environment in the vicinity of the tall buildings. In addition, it is also found that without the green belt wind speeds in the corner flow region at the lateral sides of the building may reach 5m/s with the inflow wind speed of 3m/s，while with a properly designed green belt the corner flow speeds in the same region may decrease to 3.5m/s.

Application of the Erosion Method in Automatic Storm Identification

HAN Lei,ZHANG Yan,WANG Hongqing

2008, 44(4):  592-596. 

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3-D clustering technique is the fundamental part of storm identification. One shortcoming of the clustering technique is that the connection area between adjacent storms may cause the problem of false merger. To surmount this difficulty, a special erosion operation is used. Instead of the constant convolution mask, it uses a dynamic convolution mask which depends on the reflectivity distribution of the storm boundary. The results of the experiment show that this method can successfully recognize false merger. These advantages result in better forecast evaluation scores.

Representaion of Topological Relations between Vague Objects Based on Rough and RCC Model

GAO Zhenji,WU Lun,YANG Jian

2008, 44(4):  597-603. 

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Rough model is proposed to build vague regions based on rough sets theory after defining rough regions and rough model. Rough regions are classified into three types for study. Based on the studies of neighborhood of RCC-D-8 and the constraints of lower and upper approximate regions, 599 topological relations are obtained between simple vague regions in raster regions and described by the 4×4 intersection and inclusion matrix.

The Multifunctional Approach toward Urban Bicycle Way Network：
A Case Study of Jiaojiang in Taizhou

HAN Xili

2008, 44(4):  604-610. 

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Based on analysis of the different aims of bicycle trip and ecological service of bicycle way, the author classify urban bicycle way into four types: Traffic bicycle way； Recreational bicycle way; Urban heritage Connection bicycle way; Ecology educational bicycle way. Taking the urban bicycle way system in Jiaojiang of Taizhou city as an example, the author layouts and designs traffic bicycle ways mainly through adjusting present roads section and reusing the abandoned infrastructure corridors, to create a secure and healthy bicycle way. In order to create more continuous and interesting recreational bicycle ways in Jiaojiang, the author mainly locates this type of bicycle ways along river and the edge of hill inner city. Jiaojiang heritage connection bicycle way was planned along the traditional city streets, relic of city wall and ridge line along which gathered many temples. Ecology educational bicycle ways were planned along the higher biodiversity historical canal and natural river which connects hill and sea.

The Feasibility Analysis and Case Study for Developing Circular Economy Based on Complex Adaptive System Theory

YANG Shunshun,LUAN Shengji,WANG Ying

2008, 44(4):  611-617. 

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A swarm model is designed based on the circular economy concept model and the important character that materials circulate around circuit, with the benefit of the multi-agent modeling for complex adaptive system (CAS) theory. The results of the swarm model indicate that producer-consumer agent in recycle world performs no longer periodical change rhythms, but reaches dynamic equilibrium at the stimulation time of 150 steps. The highest limit of carrying capacity from 0.06 to 0.20. Feedback between “producer" and “consumer" has to be well operated in order to keep the system stability. Compared with present world, it behaves as four factors including technology, production, market and society that impact the feasibility in developing the circular economy in investigating area. This research builds up a series of semi-quantized analyzing indexes based on these four factors, taking Baoan District which is a fast growing area in Shenzhen as a case study. The results suggest that it should develop the weakly-related circular economy system in recent years.

Evaluation Method for Measurement of Accessibility in Urban Public Green Space Planning

LI Bo,SONG Yun,YU Kongjian

2008, 44(4):  618-624. 

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An evaluation model for measurement of accessibility of green space was proposed by using GIS. This model was facile operation and verification which armed at the planning of urban public green space. It considered comprehensively the scale of green space, the distribution of population and the cost of transit, then established the cost model objectively and exactly, finally got the consequence that could be measured. It proved that this evaluation model was more suitable for the calculation measurement of accessibility in urban public green space planning compared with other methods.

SOFM Network Based Integrated Regionalization of Cropland Conversion Pressures in China

SUN Qiang,WANG Le,CAI Yunlong

2008, 44(4):  625-631. 

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Based on SOFM network modeling, an integrated regionalization system of cropland conversion pressures in China was established. Firstly, considering both supply and demand pressures, an index system of cropland conversion pressures was built, including 7 subsystems, and 10 factors at provincial level were selected as basic indicators. Second, through the factor analysis, 10 variables were compressed to 6 orthogonal factors. Thirdly, using these 6 factors as input variables, a SOFM neural network was set up. When the neural network was trained appropriately, it classified the data sets. As a result, the 31 provincial districts in China were classified into 9 groups, reflecting clear regional distinctions among the east, middle and west. On the basis of the classified results and such regionalization rules as all-around factors, relative consistency, regional conjugations and district integrality, the whole nation was divided into 4 regions of cropland conversion pressures and 25 sub-regions, and the result was shown as a regionalization map by GIS. At last, different management targets to sustainable cropland uses for different regions were put forward.

Study on Green Space Gradient Analysis and Adaptive Management in Beijing

SUN Haiqing,XU Xuegong

2008, 44(4):  632-638. 

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Taking Beijing region as a case study, changes of green-space patterns are tracked by analyzing the data of land use. Green-space is very important to planning overall nature and human being in the development of cities. Applying spatial analytical methods of GIS, the green-space information is picked up from the map of land use survey in 1996 and 2004. Basing on gradient analysis of sample zones and buffers, the character of changes of green-space patterns and its influence factors are found that green-space in the suburb changed the most observably and the decreasing areas were mostly along the roads. Because of the difficulty of uncertainty of change and decision-making, the adaptive management countermeasures should be introduced, including renovating development ideas and planning scientifically in order to ease up the drastic competition between different land uses in Beijing.

The Development of 5- to 8-Year-Olds' Theory of Mind

WANG Yan SU Yanjie

2008, 44(4):  639-646. 

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This study aimed to explore the developmental sequence of theory of mind after age 5, and to examine the relationship among different components of theory of mind. Picture-story method was used and four theory-of-mind tasks, including first-order false belief, second-order false belief, interpretive theory of mind and faux pas understanding were carried out. The results indicate that 5-year-olds can wonderfully understand first-order false belief. Interpretive theory of mind and second-order false belief understanding develope at similar age, 6-8 year old is the critical developing period for both of them. 6-year-olds can detect faux pas, but even 8-year-olds can not understand the cognitive and emotion components in faux pas. Drawn on the correlation and regression results, the first-order false belief understanding seem to be the foundation of the later developed interpretive theory of mind, second-order false belief understanding and faux pas understanding.

High Resolution Satellite Image of a Very Short Range Torrential Rain

ZHANG Chunxi,WANG Yingchun,WANG Ling,DING Qinglan,TAO Zuyu

2008, 44(4):  647-650. 

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A 100-year return period heavy rain event of 220mm precipitation in 80 min happened at mountainous areas in north of Beijing on August14, 2005 was studied with the help of the visible cloud images of 1.25km resolution from FY2-C geostationary satellite. The results show that the initial convective cells with several kilometers of horizontal scale can be identified by using the high resolution satellite images ahead of 1.0-1.5 h of rainfall, and the intense of the convective cell can be estimated by the shadows projecting on the ground. The horizontal scale of the convective clouds develope to couples of ten km just prior to the rainfall, and the shadows on the flat cloud top indicate that the convection is extremely intensified and breaks up through the tropopause.

The Trend of Landscape Planning as Shown through Publications in the Journal of Landscape and Urban Planning during the Past Twenty Years

XI Xuesong,YU Kongjian,HU Jiawen,SONG Yun

2008, 44(4):  651-660. 

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Landscape and Urban Planning is a core journal of studies in landscape planning. The authors analyze about 1604 articles published in this journal from 1986 to 2005. Statistic analysis was done for regional distribution patterns of authors, institutions, study subjects and study objects. The authors reveal the rules and characteristics of the articles published within the 20 years and the current focus and trend of landscape planning worldwide.

中图分类号Q141

HAN Wenxuan,FANG Jingyun

2008, 44(4):  661-668. 

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Yoda's -3/2 power rule or law of self-thinning based on the isometric scaling growth of plant, as well as a -4/3 law of self-thinning based on the energy equivalence ecological theory and the allometric relationship between metabolic rate and body mass of individuals are reviewed. Although the existence of a general self-thinning trajectory with a slope of -3/2 is questioned extensively, there is no evidence to reject the -3/2 power rule as the upper limit boundary line, below which all size-density trajectories possibly occur, and to accept the -4/3 power rule as the substitute. The authors suggest a re-evaluating of the -3/2 as well as -4/3 power law of self-thinning, from the first principles to the representation.