bluuebunny/crossref_metadata_2025 huggingface dataset:
Grain Boundary Sliding Below Ambient Temperature in H.C.P. Metals
Authors: Sato Eiichi , Matsunaga Tetsuya
Published: February 2012

Hexagonal close-packed metals and alloys show significant creep behavior with extremely low activation energies at and below ambient temperature even below their 0.2% proof stresses. It is caused by straightly-aligned dislocation arrays in a single slip system without any dislocation cuttings. These dislocation arrays should, then, pile up at grain boundary (GB) because of violation of von Mises' condition in H.C.P. structure. The piled-up dislocations have to be accommodated by GB sliding. Electron back scatter diffraction (EBSD) analyses and atomic force microscope (AFM) observations were performed to reveal the mechanism of GB sliding below ambient temperature in H.C.P. metals as an accommodation mechanism of ambient temperature creep. EBSD analyses revealed that crystal lattice rotated near GB, which indicates the pile up of lattice dislocations at GB. AFM observation showed a step caused by GB sliding. GB sliding below ambient temperature in H.C.P. metals are considered to compensate the incompatibility between neighboring grains by dislocation slip, which is called slip induced GB sliding.
Seventy-Five Years of Superplastic Research: An Overall Perspective for the Superplasticity Conferences
Authors: Langdon Terence G.
Published: February 2012

The origin of true laboratory-scale superplasticity may be traced to a publication appearing seventy-five years ago in 1934. This overview examines the subsequent major developments in obtaining a fundamental understanding of superplastic flow and then looks to the future to summarize very new developments that provide the potential for invigorating the field of superplastic research.
Constitutive Relations for Superplastic Flow Modeling from Two Axial Loading Experiments
Authors: Akhunovaa A. , Dmitriev Sergey A. , Kruglov A.A. , Safiullin Rinat V.
Published: February 2012

A critical analysis of approaches to find constitutive relations from the tests on uniaxial and two axial loading is presented. Then we report on the methodology of fitting parameters of constitutive relations for superplastic forming based on the results of cone cup and elongated wedge cup tests. Optimal cone and wedge angles are estimated analytically and also from the results of finite element simulations. Our methodology is based on comparison of the experimental results and the results of numerical simulations of the corresponding tests in frame of the commercial software such as ANSYS10.0 (ED). We carry out numerical simulations of the cone cup and the wedge cup tests for different sets of parameters of the chosen constitutive relation and different values of friction coefficient in order to reproduce the experimental results. The parameters corresponding to the best fit of the experimental data are then recommended for the use in computer simulations of the superplastic forming of commercial products.
The Effects of Specimen Geometry on the Accuracy of Tensile Testing of Metallic Superplastic Materials
Authors: Abu-Farha Fadi K. , Nazzal Mohammed A. , Curtis Richard
Published: February 2012

This work investigates the sensitivity of a superplastic material’s tensile test to the major geometrical parameters of the selected test specimen. This required generating a large number of specimens by systematically varying the gauge length, gauge width, grip length and width of a standard geometry. The specimens were prepared from a moderately superplastic AZ31B-H24 magnesium alloy sheet and were then stretched at a selected rate and temperature. Deformation in each specimen was tracked via an electrochemically-etched fine grid which was particularly used to quantify the amount of material flow from the grip into the gauge region. The consequences of the latter on the accuracy of measured stresses and strains were correlated back to the corresponding geometrical parameters. Ultimately, the results were utilized to set the guidelines for selecting the optimum parameters in a “proper” specimen, for testing the unique class of superplastic materials.
High Temperature Forming Maps of Various Bulk Metallic Glasses
Authors: Ragani Jennifer , Wang Q. , Gravier Sébastien , Blandin Jean Jacques
Published: February 2012

Due to their brittleness, bulk metallic glasses (BMG) are generally difficult to form at room temperature. Casting of BMG is one way to get components but an alternative route is to use the capacity to reach particularly large strains when the glasses are deformed in their supercooled liquid region (SLR). The experimental window (temperature, time) in which high temperature forming can be carried out is directly related to the glass resistance to crystallization. Such forming windows have been identified for various bulk metallic glasses (mainly zirconium and magnesium based BMG) thanks to compression tests in the supercooled liquid region. The effects of partial crystallization on the high temperature rheologies are also discussed. Finally, forming experiments were carried out in the selected windows.
Superplastic Forming – Cost Effective
Authors: Swale Bill , Pizzingrilli Mauro , McCullagh E.
Published: February 2012

When Superplastic Forming (SPF) was offered as a production process in the mid 70’s, it became the panacea of all processes for sheet metal products designed to be made from Titanium and Aluminium materials. The claims were (1) reduced part count (2) reduced assembly time (3) weight reduction (4) monolithic parts and (5) stronger structures. Following Pearson’s work in the mid 30’s with Lead-Tin and Bismuth-Tin alloys [1], showing higher than 1000% elongation without failure, the Aluminium industry developed SPF alloys and launched into numerous commercial applications. Other research facilities focused on the potential of achieving superplasticity in Titanium alloys. This was demonstrated in the late 60’s using the now well established Ti6Al4V alloy. Considerable funding was allocated, both in the USA & UK, specifically for the development of the process. The USA focused on the military programmes and the UK on the civil (Concord) and some military aircraft. Success in these programmes and the claims made, resulted with a production process. Companies invested in suitable plant and equipment, and designers grasped the process potential and applied SPF to their sheet metal designs expecting to reap the claimed benefits.
The claims are valid if applied to correctly chosen components. All too often, the SPF manufacturing choice did not deliver its claims. In many cases cost of material, need to chemical mill and higher energy costs, were either not envisaged or taken into account. Today all processes, material cost and alternative material types have to be assessed before the manufacturing method is chosen. The aerospace industry is attacking the Buy-Fly ratio. Energy and labour cost are at a premium and these have caused the SPF and Hot Forming community to examine ways of producing products (a) from less material (b) by Hot Forming (eliminating the need to apply chemical milling to remove the alpha case) (c) questioning the material choice (CP instead of Ti6Al4V) and (d) by applying modern fabrication methods. The paper will illustrate this change in philosophy; shows today’s choices and demonstrate how the SPF process can be cost effective, and in fact still does have a major role to play in producing airframe and engine structures.
Response Function Test of Marine γ-Spectrometry with Different Detector Material
Authors: Chi Tao , Zhang Ding Song
Published: February 2012

The marine radioactivity measurement is the low-level radiation measurement, whose accuracy mainly depends on the material and design of the detector. However, the currently research results mainly focus on the qualitative research. In this paper, a Monte Carlo code MCNP was utilized to simulate the comparation of the energy spectra of several relevant γ rays recorded by detectors immersed in seawater, The detection efficiency and the effective detection distance of these detectors to the radionuclides of 137Cs dispersed in seawater were calculated．The results of our experiment shown that the effective detection distance of these detctors to γ radionuclides depends on the detector material and γ-ray energy. The LaBr detector has the best price performance ratio, however, considering the balance between the low-cost and highly detection efficiency, the NaI detector is also a better choice.
A New MPI Parallel Computing Environment Based on Fibre-Channel Token-Routing Network for Materials Simulation Research
Authors: Zeng Xiao Hui , Liu Dong Sheng , Luo Wen Lang , Fu Li Xin
Published: February 2012

In order to apply our high efficiency fibre-channel token-routing network (shortened as FC-TR network) to the field of materials simulation research, a new MPI parallel computing environment is proposed and designed, and independently developed a parallel programming environment FC-TR-MPI based on FC-TR network. In FC-TR-MPI, a new method was applied to point-to-point communication that the network communications between processes in the same computing node were changed into memory operations; moreover, according to the underlying software and hardware features of FC-TR network, new algorithms were proposed to optimize the communication performance of some collective communications. Experimental results show that, compared with ScaMPI parallel programming environment, FC-TR-MPI has a higher parallel efficiency and speedup.
Temporal and Spatial Variation of Vegetation Coverage in Beijing-Tianjin-Hebei Metropolis Circle with MODIS Vegetation Indices Data Product
Authors: Li Ya Qing , Li Xiao Juan , Lian Jian , Wang Rong Hua
Published: February 2012

This paper describes the temporal and spatial variation of vegetation coverage in Beijing-Tianjin-Hebei Metropolis circle using 1km MODIS vegetation indices data product (MOD13A3), and the main satellite data used in this study were MODIS NDVI and EVI data, city borderline data and DEM. After processing data with ENVI software, the time-series maps of the NDVI and EVI were drawn by ArcMap software, and the curve charts were formed by Excel. By using the temperature, rainfall data and vegetation distribution data, the spatial and temporal variation of the VI was analyzed. The results shows that the MODIS VIs varies with season, and the curves of their monthly mean values are downwards opening quadratic parabolas, with the maximum appeared in June and July. The spatial distribution of MODIS vegetation indices is positively correlated with vegetation coverage, and appeared regional characteristics. The vegetation coverage of Beijing-Tianjin-Hebei Metropolis circle has obviously increased during the past years, due to the ecological project operated in the research region.
Effect of Sodium Chloride on Growth, Gas Exchange, Protective Enzyme of Periploca Sepium Bunge
Authors: Sun Jing Kuan , Lu Zhao Hua , Li Tian , Tian Jia Yi
Published: February 2012

Periploca sepium Bunge. was tested for salinity tolerance in pot experiments using three levels of salinity, 50, 100, and 200mmol/L.It was observed that the plant growth parameters and net photosynthetic rate (Pn), stomatal conductance (Gs) were enhanced under low salinity levels (50mm/L NaCl.),which reduced strongly with increasing salinity levels. Under 100mmol/L NaCl and 200mmol/L NaCl stress, the decline of Pn was mainly caused by non-stomatal factors.The water use efficiency (WUE), apparent light use efficiency (LUE) , apparent CO2 use efficiency (CUE) were enhanced under low salinity levels (50mm/L NaCl.), the maximum WUE was observed at 100mmol/L NaCl, the minimum WUE was observed at 200mmol/L NaCl, the LUE, CUE were reduced repectively by 52%,47% at 200mmol/L NaCl compared to control.Activities of the antioxidive enzymes superoxide dismutase (SOD), peroxidase (POD),and catalase (CAT) were enhanced by salts treatment (50mm/L NaCl.), but CAT activity decreased under 200 mmol/L NaCl salt stress. Malondialdehyde (MDA) concentration was non-significant versus the control under low salinity levels (50mm/L NaCl.),the largest concentration exposing to 200 mmol/L NaCl. These results suggest a possible use of Periploca sepium Bunge in Yellow River Delta regions,where salinity is often the common major abiotic stress for plants.
The Impact of Plant Hedgerow in Three Gorges on the Soil Chemicophysical Properties and Soil Erosion
Authors: Lü Wen Xing , Zhang Hong Jiang , Wu Yu He , Cheng Jin Hua , Li Jian Qiang , Wang Xing
Published: February 2012

Through the research and sampling analysis on different plant hedgerow in sloped farmland in Three Gorges reservoir area, we will conduct research on the impact of plant hedgerow in Three Gorges on the chemicophysical properties of soil and soil erosion. The results show that the plant hedgerow mainly composed by Morus alba, Citrus reticulata, Zanthoxylum bungeanum, Vitex negundoand Begonia fimbristipula can decrease the soil density as well as sand content and increase soil porosity, soil water content, silt content and clay content to some extent. The organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil in different locations in plant hedgerow indicate as maximum in on-band, minimum in inter-band, middle both upper-band and below-band. In the same slop with no plant hedgerow, the organic matter, nitrogen, phosphorus, potassium and cation exchange capacity and other chemical indices of soil show a trend of increasing from the top to the bottom of the slop, which reveals that these substances own a feature of accumulation by moving to the bottom. The strength of soil anti-corrosion in different plant hedgerow is: Vitex negundoand (79.2%)> Citrus reticulata (36.4%)> Morus alb (22.4%)> Zanthoxylum bungeanum (18.9%)> Begonia fimbristipula (15.3%)> CK (8.7%), and the soil anti-corrosion indices in plant hedgerow are decreasing with the increase of soil immersion time, besides, the former and the latter are 3 times polynomial function. For those 5 plant hedgerows, Vitex negundoand owns the best impact on improving soil chemicophysical properties and reducing soil erosion.
Retrieval of Water Use Efficiency Using Hyperspectral Indices: An Application for Tamarix ramosissima
Authors: Wang Shan Shan , Chen Xi , Wang Quan , Bao An Ming
Published: February 2012

Many fundamental ecosystem properties and dynamics are monitored by plant water status, particularly in arid ecosystem where water is usually limiting. Although plant water status have been widely assessed using field measurements by ecological methods, approaches for remotely sensing plant water status are largely lacking, particularly diurnal water status. In arid ecosystem, WUE is a dynamic indicator for detecting water status, but also an integrated index for correlating to the plant photosynthesis. In our study, the experiments were conducted on native dominant desert shrub, Tamarix ramosissima, in their original habitats on the southern periphery of Gurbantonggut desert, China. We explored sensitive and useful hyperspectral indices for estimating diurnal WUE at a leaf scale based on diurnal measurements of hyperspectral reflectance, photosynthesis and micrometeorological variables. According to the statistical analysis of relationships between spectral indices and WUE estimation, SR type hyperspectral index is the sensitivity index for WUE estimation. Our results provide useful insights for monitoring desert shrubs diurnal and dynamic water status, using a wide range of available hyperspectral data.
The Quantitative Evaluation of Coal Seam Stability Based on Component GIS
Authors: Chen Long Quan , Kuang Run Yuan
Published: February 2012

The stability of the mining is important for coal, and stability of the current status of coal was analyzed, selecting appropriate indicators that evaluate the importance of stability of the coal seam is so significant. Using GIS Spatial database to achieve a unified data management for spatial data and attributes, and analyze of coefficient of variation of coal thickness and correlation dimension of coal thickness, and use of these two indicators of a coal mine in the coal seam to analyze stability evaluation. Finally, developed stability assessment system of coal based on component-based GIS MapX. The results show that quantitative evaluation of the stability of the coal is reliable, can provide a theoretical basis for coal mining.
Treatment of Cotton Pulp Black Liquor Using Micro-Electrolysis in Sequencing Batch Reactor
Authors: Duan Ting , Xing Mei Yan , Li Ming Zhuo , Liu Zheng Zhong , Liu Wen , Yang Jian
Published: February 2012

Micro-electrolysis process was conducted to treat the anaerobic digestion effluent of cotton pulp black liquor in sequencing batch reactor (SBR). Three key factors including reaction time, pH, and iron-carbon volume ratio were investigated for their impacts on the treatment efficiency. The effluent of micro-electrolysis polished by coagulation process was performed with Al2(SO4)3and PAC as coagulators. The results show that the optimum conditions of the micro-electrolysis treatment were pH 5.5, iron-carbon volume ratio 1:1, and reaction time 8h. Al2(SO4)3was selected as the coagulator with the addition of 400mg/L. The removal efficiency of COD reaches 93.2% with Micro-electrolysis combined with coagulation process. In addition, the B/C ratio has risen from 0.016 to 0.68(>0.3), which creates favorable conditions for the subsequent aerobic process. Consequently, the micro-electrolysis and coagulation process are highly efficient to dispose the anaerobic digestion effluent of cotton linters pulp black liquor. What’s more, this technology has the advantages of low operating cost, small land occupation and high efficiency.
Study on Tribological Properties of the Sealing Material CrMo Cast Iron
Authors: Yan Yu Tao , Sun Zhi Li , Hu Guang Yang , Hu Tian Qi
Published: February 2012

For increasing the experimental efficiency and shortening the experimental time, the uniform design method was used to establish the wear experiment scheme on the tribological properties of the sealing material CrMo cast iron. The experiments were investigated on a vertical universal friction and wear tester, the worn surfaces of specimens were observed by scanning electron microscope (SEM). The results showed that the experiment points chosen by the uniform design is reasonable and effective, and the wear rate distribution rule of the CrMo cast iron was established and was divided three regions, the effect on wear rate in the I region and the III region was more serious than the II region, and the variation of the friction coefficient is bigger under experimental conditions, the main wear mechanism of the CrMo cast iron is desquamation wear and adhesive wear. The load and sliding speed coupling effect on wear of the CrMo cast iron must be thought over.
Evaluation of BER in Optical Packet Switching Using Various Coding Schemes
Authors: Kavitha A. , Rajamani V. , Anandhakumar P.
Published: February 2012

Performance analysis of optical transmission using three codes viz. 8B/10B code, Systematic code and Viterbi code is presented in this paper. Peak power and bit error rate on the physical layer have been computed and the performance of codes is analyzed using bit error rate. The range of BER found in this paper is 8.61e-014μW, 1.7308e-011μW and 1.276e-013μW for 150Km, 130Km and 140Km of 8B/10B code, Systematic code and Viterbi code respectively.
Millimetric Waves Technologies: Opportunities and Challenges
Authors: Chimeh Jahangir Dadkhah , Parapari Saeed Bashirzadeh , Mousavinejad Seyed Mohmoud
Published: February 2012

Providing an available wideband and better antenna beam forming are two good profits of millimeter wave (mmWave) technology. MmWave technology makes radio systems lighter and smaller and radars more precise. Today, commercial MmWave equipment work below 90GHz frequencies. MmWave radios work to transport Internat traffic in the backhaul of communication networks. There is a challenge in mmWave technology since the prices of equipment increases as the frequency increases. In this paper we study the applications of mmWave technology, its products, standards and compare it with other wireless technologies.
A Design of Ring-Shaped LED Driving Circuit Used in Optical Instruments Illuminating System
Authors: Tang Liang Bao , Zhou Hai Ying , Wei Zhe , He Xiang Yan
Published: February 2012

According to the requirement of optical instrument illuminating system and performance characteristic of Ring-Shaped LED, a constant current circuit based on PT4115 chip is designed to drive Ring-Shaped LED. It is proved that not only the LED′s light intensity can be conditioned by PWM, but also its heat dissipation can be solved effectively. Moreover, compared with traditional halogen lamps, it has the advantage of the small volume and low-cost. Therefore, it can be widely applied to optical instrument illuminating system. This paper is applies innovative. Ring-Shaped LED of base on Amega 16 and PT4115 is applied for optical instrument illuminating system.
A Microwave Sensor for Contact-Free Measurement of Human Heart Rate
Authors: Lu Guo Hua , Yang Fang , Jing Xi Jing , Yu Xiao , Wang Hua , Wang Jian Qi
Published: February 2012

Measures of heart rate are widely used to assess the health state of human in clinic. Tranditional method uses eletrodes touching the body to monitor electrocardiography (ECG) .A micorwave sensor was disscused to remote sense the heart rate without touching human body. Comparison of heart rate derived from the microwave sensor and ECG demonstrated that there were no significant differences, which suggested this sensor may prove a practical alternative to ECG for heart rate measurement.
Porous Materials of Carbonate Rocks under the Condition of Low Temperature and High Pressure
Authors: Shan Zhi Gang , Kuang Hong Hai , Kuang Ming Sheng , Zhou Chun Hong
Published: February 2012

There are significant impacts on the safty of tunnels because of porous materials.In order to avoid serious accidents of tunnels, Porous materials of carbonate rocks under the condition of low temperature and high pressure have been studied in the paper. Samples of local carbonate rocks have been collected from carbonate rock formation. Special machine was designed to simulate the condition of low temperature (10°C-20°C ) and high pressure (1-30Mpa) undergroud 4000M in jinping.Samples of local carbonate rocks have been tested in the machine. Spectrographs and scanners have been used to observed the change of porous materials of carbonate rocks.Results of the technological measurements show that the change of porous materials of carbonate rocks is affected by low temperature and high pressure.With the change of low temperature and high pressure, surface chemistry is affected throughout the surface of carbonate rocks. When the temperature of carbonate rocks exceed 15°C and pressure less than 18Mpa,there will be new compounds on the surface of carbonate rocks. These new compounds will change the porosity and thesaturated permeability of carbonate rocks.The change may led to serious accidents of tunnels.If we want to avoid these serious accidents,we must keep the temperature of carbonate rock formation less than 15°C and pressure exceed 18Mpa.
A New Linearly Polarized Microwave Radiometer Calibration Source
Authors: Wang Xin Biao , Zeng Chang , Li Jing , Jiang Jing Shan
Published: February 2012

This paper introduces a calibration device for microwave (millimeter and submillimeter) radiometer. The device can provide the microwave radiometer continuously variable linearly polarized noise temperature. The paper also introduces a real-time calibration method to achieve the microwave radiometer calibration, and the test of microwave radiometer sensitivity and linearity.
A RELAX Based Method for Spotlight SAR Imaging
Authors: Ren Xiao Zhen , Qin Yao , Fu Hong Liang
Published: February 2012

The imaging problem of spotlight SAR is converted to a parameter estimation problem of several monochromatic signals in additive white Gaussian noisy condition in this paper. Moreover, a spotlight SAR imaging algorithm based on RELAX is presented in detail. Traditional polar format algorithm and the presented method are applied to spotlight SAR imaging respectively, and the imaging results are compared. Simulation results show that the polar format algorithm doesn’t give satisfactory imaging results, while the proposed method adapts the noisy environment better and obtains better results.
An Atmospheric Correction Method for Medium Resolution Spectral Imager Thermal IR Soundings
Authors: Liu Hai Lei , Xu Li Sheng , Ding Ji Lie , Sang Ba , Deng Xiao Bo
Published: February 2012

Based on the thermal radiative transfer equation (RTE), a new atmospheric correction method named Single Band Water Vapor Dependent (SBWVD) method is developed for land surface temperature (LST) retrieval for the FY-3A Medium Resolution Spectral Imager (MERSI) with only one thermal infrared (TIR) channel. Assuming that the surface emissivity is known, water vapor content (WVC) is the only one parameter for input to the SBWVD algorithm to retrieve LST from MERSI TIR observations. FY-3A MERSI Level 2 water vapor product is employed to evaluate the performance of the proposed method, and a 2-D data interpolation procedure is applied in order to match the MERSI L1B data in spatial resolution. Some tests, including numerical simulation for MERSI sensor and the synchronous measurements of MERSI and the radiosondes for the radiative calibration of the FY-3A tests in Qinghai Lake, have been carried out for the proposed algorithm, respectively. The results show that the difference between the retrieved LST and the in-situ measurements is less than 0.6 K for most situations. The comparison with the MODIS LST products (V5) shows that the root mean square error (RMSE) is under 0.72 K. Thus, our proposed new algorithm is applicable for the atmospheric correction and LST retrieval using MERSI TIR channel observations.
Indoor Microwave Scattering Properties Measurement and Study of Soil
Authors: Pang Shao Feng , Chen Yan , Jia Ming Quan , Tong Ling
Published: February 2012

Microwave scattering properties study of soil is a very important microwave scattering mechanism element, it is the basis of the study on backscattering model for remote sensing and electromagnetic parameters inversion. The paper describes the principle, the buildup and the measurement process of the indoor microwave scattering measurement system first. Then we focus on the microwave scattering properties study of the soil, carrying out abundance measurements under different types of roughness, different water content, different polarizations and different angles of incidence. By comparing the measurement data with the model of AIEM, the system is proved to be of satisfactory performance and can get the scattering property of the measurement sample with high precision, which can lay a solid foundation for the deeper research on the mechanism of the microwave remote sensing of soil.
Exploration of Remote Sensing Image Processing Method for Glacial Geomorphology Research
Authors: Zhao Shang Min , Cheng Wei Ming , Chen Xi
Published: February 2012

Taking Mt. Namjagbarwa region as an example, this paper explores a complete remote sensing image processing method for glacial geomorphology research. Based on the selection of Landsat7 ETM+ images, the remote sensing image processing method such as band selection, overlap, fusion, mosaic and so on is carried out. The result shows: ① right selection of remote sensing images and proper process based on the characteristics of research area and research purpose, not only reduce the process difficulty, but make a firm foundation for subsequent glacial geomorphology research; ②according to the computation of correlation coefficient between fusion images and original multi-spectral images, panchromatic high resolution images, the result shows that the principle component transformation method has better effect than IHS transformation method in remote sensing image fusion process.
Extracting Rural Settlement Information from Quickbird Images
Authors: Yang Cun Jian , Luo Zhen
Published: February 2012

Acquiring the information for rural settlement timely and accurately has an important significance for construction and development of rural areas. The development of remote sensing technology provides advanced means of the acquirement of the information of settlement. The study of extracting rural settlement information from Quickbird images in Xindu district, Chengdu City, P.R.of China was discussed here. Firstly, The Quickbird images such as panchromatic image and multi-spectral images were processed by geometric correction, enhancement and fusion. Secondly, the homogeneous image objects were formed by using multi-scale segmentation technology based on knowledge. Thirdly, the features such spectral feature, spatial relationship feature, texture feature and geometric feature of the image objects were obtained for each image object by using feature calculation. Fourthly, the feature knowledge of rural settlement unit and its component were obtained by using knowledge discovering. Finally, the rural settlement unit and its component information were extracted by matching the features with the feature knowledge of rural settlement unit and its component based on reasoning. It was shown that the rural settlement unit and its component information can be effectively extracted from Quickbird images by using our proposed method in this paper.
Segmentation of Green Vegetation from Crop Canopy Images Based on Fisher Linear Discriminant
Authors: Zheng Li Ying , Tian Kai
Published: February 2012

One crucial problem with applying digital image analysis technology to the field of agriculture is separation of green vegetation regions. In this paper, a new crop canopy image segmentation algorithm, which is based on Fisher linear discriminant and the values of red, green and blue of each pixel in an image, is presented. First, 90 green vegetation regions and 80 non-green vegetation regions, each of which has nine pixels, from two crop canopy images were chosen to generate training data. Then, the optimal projection direction is determined by using the Fisher linear discriminant. Finally, a color crop canopy image is divided into two parts—green vegetation and non-green vegetation---with a fixed threshold. The algorithm’s performance was assessed on 50 images. The results on 50 images show that the median of mis-segmentation of proposed method is about 5%. The comparisons between the proposed algorithm and those based on color indices show that the former outperforms the latter with high segmentation rate and fast running speed.
An Object-Based Basic Farmland Change Detection Using High Spatial Resolution Image and GIS Data of Land Use Planning
Authors: Zhang Peng Lin , Ruan Bo Lin , Chao Jian
Published: February 2012

With the rapid development of urbanization in China, an effective and quick approach usedto identify changes in basic farmland becomes more and more important in land use resource managementfield. While a variety of change detection approaches using multi-temporal satellite image havebeen reported, few approaches using GIS data of land use planning and single-temporal high spatialresolution satellite image have been reported. This paper proposes an object-based basic farmlandchange detection approach using single-temporal high spatial resolution satellite image and GIS dataof land use planning. Compared with the pixel-based change detection approach, the object-based approachmust be more suitable for in high spatial resolution images. To test the validity of the proposedapproach, we apply it to the actual data, and primary results reveal that the proposed approach is valid.
Object-Oriented Information Extraction of Farmland Shelterbelts from Remote Sensing Image
Authors: Shi Xiao Liang , Li Ying , Deng Rong Xin
Published: February 2012

It has become an important means of shelterbelts surveying using high resolution remote sensing image to access the distribution of farmland shelterbelts. However, traditional classifications of remote sensing image based on spectrum characteristics of single pixel, and didn’t consider the factors including relativity and structure characteristics of the neighboring pixels, which will lead to lower accuracy of feature extraction for high resolution remote sensing image. On the basis of object-oriented classification method and the module of ENVI Feature Extraction, the paper extracted the shelterbelts distribution through image segmentation and rules establishment for the Spot5 high resolution remote sensing image in the Midwest of Jilin Province, and the extraction accuracy is 91.3%.The result shows that the method can accurately extract farmland shelterbelts from high resolution remote sensing image.
The Comparative Study on the Automatic Extraction Methods of Artificial Channel Based on ETM Image
Authors: Lu Cheng , Li Qiang , Yu Li Jun
Published: February 2012

It’s urgent for China to solve the water shortage. Quickly and accurately extracting water resources from satellite remote sensing has become an important means of the investigation and monitoring of water resources and wetland protection. The fact that the spatio-temporal span of channel is large made the investigation difficult especially by the conventional way. Remote Sensing plays an increasing important role in the water resources protection with advantages of large scale, integration, dynamics and fastness. The RS images recorded the truth of the surface landscape in history and can reflect the distributing and the status quo of the channel in different courses of history. The article analyses the spectral and spatial feature of channel in ETM images in order to extraction the channel automatically with the different RS methods combined with GIS technology. A comparison among these methods is made. In addition, the article assesses the results of single-band method and multi-band method qualitatively and quantitatively. This study provide a scientific basis for the protection of water resource.
Dynamic Adaptive Weight Multi-Scale and Multi-Structure Morphological Edge Detection in Anterior Chamber OCT Images
Authors: Huang Si Wei , Zhang Ang , Tian Xiao Lin , Sun Yan Kui
Published: February 2012

An edge detection algorithm which is applied to anterior chamber OCT images has been proposed. The algorithm firstly uses multi-structure elements to detect edge on gray level value differences on the same scale, and introduces dynamic adaptive weight to make re-fusion of pixels to gain a multi-structure element morphological edge detection image on the same scale, then confirms weight value and makes multi-scale fusion according to the noise immunity of different scale structure elements to gain the final edge detection image. The simulated results have obvious edge features,it can effectively avoid the occurrence of mutational pixels on the OCT image edge results, compared to traditional edge detection algorithms.
Image Fusion Base on K-Means Clustering and Contourlet Transform
Authors: Wang Liang Ku , Li Cheng Jin , Wang Qing , Yang Zhao Hui , Wang Zhi Jie
Published: February 2012

The robustness of K-means clustering is poor in non-spherical distribution data, in order to improve the universal ability of clustering algorithms, the cross-entropy distance measure was used to replace the Euclidean distance measure . Contour let transform, not only has characteristics of multi-resolution, locality and critical sampling which wavelet has, but also has the characteristics of multiple decomposition directions and anisotropy which wavelets lack. So we combine the modified K-means clustering and Contour let transform to apply for image fusion. Experimental results show that this method is feasible.
A New Kind of Integrating Sphere Radiation Calibration System for Satellite Remote Sensors
Authors: Guo Ting Liang , Feng Guo Jin , Wang Yu , He Ying Wei
Published: February 2012

A new kind of half integrating sphere radiation system that has the adjustable area of radiating surface in the 380nm-2500nm wave band is introduced in this paper. The opening diameter of the integrating sphere reaches to Φ600mm. Half Integrating sphere radiation system is mainly composed of a half sphere, extension part, cyclic annular baffles and other components. The diameter of half-integrating sphere is Φ1800mm. The radiance uniformity through opening reaches up to 98%. Systems can now be used for all types of large field of view of satellite remote sensor for the calibration of spectral radiance; in addition, it can also be applied for various types of light exposure calibration such as flash lamp and so on.
Simulation and Design on a New Uniform Radiation Source for Calibration of Satellite Remote Sensors
Authors: Guo Ting Liang , Feng Guo Jin , Wang Yu
Published: February 2012

High-precision calibration of space sensors is a complex task. For calibration, integrating sphere system is the main equipment to produce large area uniform radiation source. Such integrating spheres are usually very huge with large diameters, generally more than one meter. Furthermore, such a large integrating sphere costs very high. In order to reduce the size of integrating sphere and cost, the necessary pre-simulation is very necessary. In this paper, a new semi-integrating sphere with 1300mm diameter was designed by using of ray-tracing algorithm on different special structures to improve the design efficiency. The results showed that, 1. The output of semi-integrating sphere system is more sensitive to its inner light source location and the aperture. 2. The practical measurement of semi-integrating sphere is approaching to the simulation findings. Although the opening diameter of semi-integrating sphere reaches to 50% of the diameter of semi-integrating sphere, the output radiance uniformity is still larger than 95% and with better performance.
Wide Frequency Tunable GaSe Terahertz Emitter under Collinear Phase Matching Condition
Authors: Dezaki Hikari , Tanabe Tadao , Jin Hai Yan , Oyama Yutaka
Published: February 2012

1.2μm – laser pumped wide frequency tunable coherent terahertz (THz) light source is demonstrated. The operation principle is based on difference frequency generation (DFG) with an excitation of phonon – polariton in Gallium Selenide (GaSe) crystal. The pump and signal lasers used are 1.2μm Cr:Forsterite lasers. The tuning range of the THz wave frequency covers from 0.3THz to 4.8THz (typeeoophase matching) and 8.3THz to 10.2THz (typeeoophase matching) under collinear phase matching conditions. It is shown that the maximum conversion efficiency is up to ~10-6, which is 3 orders in magnitude larger than that of Gallium Phosphide (GaP) crystal.
Estimating Rice LAI Based on Digital Camera and Image Processing
Authors: Pan Gui Ying , Zhou Lian Qing , Shi Zhou
Published: February 2012

A fast, low-cost method for rice canopy leaf area index (LAI) estimation is proposed. Take photos of rice canopy with a 57° view angle from above using a common digital camera. Extract canopy gap fraction by digital image processing technology. Then LAI can be estimated using canopy gap fraction based on optical transmission model and Leaf angle distribution model. AccuPAR-LP80 and direct measurement were employed to provide Comparative data. Comparison of the three methods, we obtained high correlation coefficients (R²≥0.6). The result shows that the method is especially suitable for estimating LAI in early growth stage of rice.
Study on Image Fusion Model Based on HIS Transform and Nonsubsampled Contourlet Transform
Authors: Cao Min , Tan Shan Shan , Shen Quan Fei
Published: February 2012

After analysising the principle of nonsubsampled contourlet transform, the image fusion model based on HIS transform and nonsubsampled contourlet transform is proposed. By taking of ALOS image as an example, the image fusion of multi-spectral band and panchromatic band at the same time is carried out by different fusion methods such as the method combining HIS transform and nonsubsampled contourlet transform (NSCT), HIS transform fusion method, principal component analysis (PCA), Brovey and static wavelet transform (SWT). By calculating the quantitative evaluation indicators of the different fused image, it is conclued that the fusion effection of static wavelet transform fusion method and nonsubsampled contourlet transform fusion method is better than the common methods such as HIS transform, principal component analysis and Brovey. In particular, the image fusion effection of nonsubsampled contourlet transform method, which betterly maintains the image spectral information while improving image spatial resolution at the same time, is superior than the fusion evaluation of static wavelet transform fusion method.
Room Temperature Terahertz Emission via Intracenter Transition in Semiconductors
Authors: Dezaki Hikari , Jing Meng Long , Balasekaran Sundararajan , Tanabe Tadao , Oyama Yutaka
Published: February 2012

An efficient continuous wave (CW) THz source working at nominal room temperature is described. Optically pumped room temperature THz emission is observed from various kinds of semiconductor bulk crystals. In order to investigate the emission mechanism, temperature dependences of terahertz emission intensity in various semiconductors are measured. Semiconductor samples used are InSb, InSb:Ge, InAs, GaSb, Ge, and Si. From these results, it is shown that the temperature dependences of emission characteristics are different between direct and indirect transition semiconductors, and that the high resistive Ge is suitable for room temperature THz emitter via intracenter transitions excited by IR pump lasers.
Research on Drought Monitoring of Fuxin Based on MODIS Data
Authors: Wang Chong Chang , Zhou Chun Feng , Yang Yan Yan
Published: February 2012

In this paper, the temperature vegetation dryness index （TVDI） method and thermal inertia index method are designated as the way of modeling drought monitoring in Fuxin. First, the temperature vegetation dryness index and the thermal inertia index are obtained by means of the parameters. Then with soil water content data measured actually at meteorological stations in Fuxin, the empirical models of Temperature Vegetation Dryness Index–Soil Water Content (TVDI-SWC) and apparent Thermal Inertia-Soil Water Content (ATI-SWC) are established. After regression analysis and forecasting analysis of 2006, the results clearly show that the ATI-SWC model generally outperforms TVDI-SWC model on prevernal drought monitoring in Fuxin. It can be used for quick and exact estimation of the whole drought condition of Fuxin.
An Improved Image Segmentation Method Based Onmulti-Resolution Analysis and Watershed Transformation
Authors: Wang Yan , Ma Yan
Published: February 2012

This paper presents an improved image segmentation method based on multi-resolution analysis of wavelet transform and watershed transformation. In the marked-controlled watershed segmentation, we not only enhance the contours of low-resolution input image to acquire segmentation function image, but also use minima imposition technology to apply filters to input image to acquire marked function image. In order to improve segmentation accuracy, we use regional fusion and coarse-fine segmentation in wavelet inverse transform. The experimental results show that the proposed image segmentation method can efficiently reduce over-segmentation, as well as improve the effect of image segmentation. In addition, the proposed method is robust.
Change Detection of Remote Sensing Image Based on Multi-Band KL Transform
Authors: Chen Ying , Zhao Xun Jie , Wang Qing , Yang Zhao Hui , Wang Zhi Jie
Published: February 2012

Two TM images of Suzhou City were used to extract the changed area by the multi-band KL transform. The keys of the research are the preprocessing of the images, band combination and the combination of the transformed components. Experimental results show that the method joined the information of two images, made the changed information obvious, improved the detection accuracy and was less affected by the noise.
A Proposal of Fiber Sensing System Using Low Reflectivity FBG
Authors: Li Yan Sheng , Nie Ting Yuan , Song Chuan Wang
Published: February 2012

This paper proposes multipoint optical fiber sensing system based on fiber Bragg grating (FBG) sensor array. The low reflectivity FBG sensors having the same Bragg wavelength are connected cascaded in the same fiber line as the sensing elements of optical fiber sensing system. This can increase the monitoring points and reduce manufacturing costs of FBG sensor. To verify the effectiveness, the system simulator based on equivalent circuit model by microwave technology was developed. Simulation result shows that though multi-reflections can be caused by FBG sensors with the same Bragg wavelength connected cascaded in the same line, the effect may become weak as reflectivity of FBG sensors are reduced to 0.02.
A Computer Aid Image Information Identify System
Authors: Guo Feng Ying
Published: February 2012

It introduces the design and implement of a computer aid image information indentify system. Through the image color turns to gray process、the image reduce miscellaneous bits process and the image enhanced process; the magnetic images on the cannonball are showed clearly on computer. And then through indentify and contrast technology, cracks on the cannonball can easily to be judged. The productivity is improved. The programme is developed by Visual C++.
Performance Bound of Position Estimation in Image Matching
Authors: Xu Bao Shu , Shi Ze Lin
Published: February 2012

Position estimation in image matching is a fundamental step in computer vision and image processing. To deal with the problem of performance prediction, we formulate it under statistical parameter estimation aspect. The lower bound of position estimation variance is obtained based on Cramer-Rao lower bound (CRLB) theory. This paper analyses the impact of noise to 1-D signal matching, derives the lower bound of variance, and then extends it to 2-D image matching. Furthermore, we derive numerical expression that can be computed from observed data. Finally, we use Monte Carlo simulation method to verify the derived analytical expressions. Experimental results show that the derived CRLB is tight to simulation estimated variance. The CRLB can characterize the performance bound of position estimation in image matching.
Improved Multi-Scale Segmentation Algorithm for High Spatial Resolution Remote Sensing Images
Authors: Liu Rui , Wang Shi Xin , Zhou Yi , Shao Zhen Feng
Published: February 2012

An improved multi-scale segmentation algorithm is proposed in this paper. In order to get segmentation result more efficiently and accurately, watershed transformation is used as an initial segmentation algorithm, and then the objects of regions are merged based on the improved merge rule. The improved regulation for region merging is mainly based on the scale parameter of area-based while the heterogeneity parameter is considered as well. In this way, the failure of considering that some regions with large heterogeneity with their neighborhood are not suitable for merging will be prevented. Experimental results show that the quality and efficiency of remote sensing image segmentation can be greatly improved by the improved multi-scale segmentation algorithm.
Rapid Manipulation Method for Massive Remote Sensing Images Based on LRU Algorithm
Authors: Wang Chun Hui , Wu Yang , Yu Jia Zi , Zhang Deng Rong
Published: February 2012

With the rapid development of remote sensing (RS) technology, RS image data is growing larger and larger, which makes general image manipulation method limited in feasibility, speed and efficiency. In this paper, a rapid manipulation method of massive RS data based on Least Recently Used (LRU) algorithm in operating system page scheduling is proposed. Its core content includes data read-write based on memory mapping, data organization based on image pyramid with layers and blocks and caching based on LRU algorithm. The experiment shows that this method can greatly increase the speed and efficiency of massive RS images processing.