Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estim...Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estimate the azimuth angle and the gyro constant drift in the paper. The relative errors which affect the estimation accuracy of the azimuth angle are the analysed.展开更多
Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method br...Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.展开更多
Application of particle image velocity (PIV) techniques for measuringparticle size distribution and total number in an activation chamber of desulfurization system isintroduced. Watersheld algorithm is used to choose ...Application of particle image velocity (PIV) techniques for measuringparticle size distribution and total number in an activation chamber of desulfurization system isintroduced. Watersheld algorithm is used to choose the suitable initial gray level threshold whichis used to change the gray level images taken by PIV to black and white ones, then every particle inan image is isolated totally. For every isolating particle, its contour is tracked by the edgeenhancement filter function and kept by Freeman s chain code. Based on a set of particle s chincode, its size and size distribution are calculated and sorted. Finally, the experimental data ofcalcium particles and water drops, separately injected into the activation chamber, and the erroranalysis of data are given out.展开更多
According to the characteristics of gravity passive navigation, this paper presents a novel gravity passive navigation system (GPNS), which consists of the rate azimuth platform (RAP), gravity sensor, digitally st...According to the characteristics of gravity passive navigation, this paper presents a novel gravity passive navigation system (GPNS), which consists of the rate azimuth platform (RAP), gravity sensor, digitally stored gravity maps, depth sensor and relative log. The algorithm of rate azimuth platform inertial navigation system, error state-space equations, measurement equations and GPNS optimal filter are described. In view of the measurements made by an onboard gravity sensor the Eotvos effect is introduced in the gravity measurement equation of a GPNS optimal filter. A GPNS is studied with the Matlab/Simulink tools; simulation results demonstrate that a GPNS has small errors in platform attitude and position. Because the inertial navigation platform is the rate azimuth platform in the GPNS and gravity sensor is mounted on the rate azimuth platform, the cost of the GPNS is lower than existing GPNS's and according to the above results the GPNS meets the need to maintain accuracy navigation for underwater vehicles over long intervals.展开更多
The cost of the gravity passive inertial navigation system will be lower witha rate azimuth platform and gravity sensor constituting a gravity measurement and navigationsystem. According to the system performance char...The cost of the gravity passive inertial navigation system will be lower witha rate azimuth platform and gravity sensor constituting a gravity measurement and navigationsystem. According to the system performance characteristics, we study the rate azimuth platforminertial navigation system (RAPINS), give the system navigation algorithm, error equations of theattitude, velocity and position of the rate azimuth platform, and random error models of theaccelerometer and gyro. Using the MATLAB/Simulink tools, we study the RAPINS and RAPINS withvelocity damping. Simulation results demonstrate that the RAPINS with velocity damping has smallerrors in platform attitude and position and satisfies gravity measurement and navigationrequirement.展开更多
In order to calibrate electrical instruments and generate a constant magnetic field, a novel design method for square Helmholtz coil is proposed. According to the superposition principle in electromagnetics, the theor...In order to calibrate electrical instruments and generate a constant magnetic field, a novel design method for square Helmholtz coil is proposed. According to the superposition principle in electromagnetics, the theory of the square Helmholtz coil is established, and the design method is verified by Matlab calculation. Compared with conventional circular Helmholtz coil, the novel square one is with a larger uniform region. Simulation work is conducted in Maxwell, and the distribution of the magnetic field is obtained. The results demonstrate the validation of the applied calculation method of the proposed Helmholtz model. The space utilization rate η is used to make a comparison between the square and circular coils for the uniform region. The square Helmholtz coil is fabricated, the length of a single square coil is 1.5 m, and the amplitude of the magnetic field is controlled by the current. The GSM-19 T proton magnetometer is used to measure the amplitude of the magnetic field generated by the square Helmholtz coil. Experimental results indicate that a wide-range variable uniform magnetic field from 0 to 120 μT is generated in the center of Helmholtz coils.展开更多
Large amplitude internal solitary waves(ISWs) often exhibit highly nonlinear effects and may contribute significantly to mixing and energy transporting in the ocean.We observed highly nonlinear ISWs over the continent...Large amplitude internal solitary waves(ISWs) often exhibit highly nonlinear effects and may contribute significantly to mixing and energy transporting in the ocean.We observed highly nonlinear ISWs over the continental shelf of the northwestern South China Sea(19°35'N,112°E) in May 2005 during the Wenchang Internal Wave Experiment using in-situ time series data from an array of temperature and salinity sensors,and an acoustic Doppler current profiler(ADCP).We summarized the characteristics of the ISWs and compared them with those of existing internal wave theories.Particular attention has been paid to characterizing solitons in terms of the relationship between shape and amplitude-width.Comparison between theoretical prediction and observation results shows that the high nonlinearity of these waves is better represented by the second-order extended Korteweg-de Vries(KdV) theory than the first-order KdV model.These results indicate that the northwestern South China Sea(SCS) is rich in highly nonlinear ISWs that are an indispensable part of the energy budget of the internal waves in the northern South China Sea.展开更多
In this paper,we present the semi-implicit Euler(SIE)numerical solution for stochastic pantograph equations with jumps and prove that the SIE approximation solution converges to the exact solution in the mean-square...In this paper,we present the semi-implicit Euler(SIE)numerical solution for stochastic pantograph equations with jumps and prove that the SIE approximation solution converges to the exact solution in the mean-square sense under the Local Lipschitz condition.展开更多
Here we report iron(Fe) isotopic data of three pure Fe solution standards(IRMM-014, GSB Fe, and NIST3126a) and five widely used geological reference materials(RMs) from the United States Geological Survey and Geologic...Here we report iron(Fe) isotopic data of three pure Fe solution standards(IRMM-014, GSB Fe, and NIST3126a) and five widely used geological reference materials(RMs) from the United States Geological Survey and Geological Survey of Japan obtained on a Neptune Plus multi-collector–inductively coupled plasma–mass spectrometer(MC-ICP-MS) in our laboratory over the past 3 years. The instrumental mass bias was corrected by three independent methods: sample-standard bracketing(SSB),Ni doping + SSB, and ^(57)Fe–^(58)Fe double spike + SSB.Measurements reveal that both the Ni doping and double spike methods helped calibrate short-term fluctuations in mass bias. Collectively, almost all measurements of RMs yielded δ^(56)Fe within ± 0.05 of recommended values,provided that each sample was measured four times on MC-ICP-MS. For the first time, new recommended values for NIST SRM3126a are reported(δ^(56)Fe = 0.363 ± 0.006,2SE, 95% CI; and δ^(57)Fe = 0.534 ± 0.010, 2SE).展开更多
This paper proposes a joint method to simultaneously retrieve wave spectra at dif ferent scales from spaceborne Synthetic Aperture Radar(SAR) and wave spectrometer data. The method combines the output from the two dif...This paper proposes a joint method to simultaneously retrieve wave spectra at dif ferent scales from spaceborne Synthetic Aperture Radar(SAR) and wave spectrometer data. The method combines the output from the two dif ferent sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coeffi cient is estimated using an ef fective signifi cant wave height(SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coeffi cient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as fi rst guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the joint method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length(PWL), and peak wave direction(PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR(ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting(ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed joint retrieval method could be a valuable complement to traditional methods used to retrieve directional ocean wave spectra, particularly in inhomogeneous sea states.展开更多
Body measuring is very important for garment sizing and pattern making. In this paper, we study the difference of the landmarks between the traditional method and 3D scanner and we also select the 19 circumference mea...Body measuring is very important for garment sizing and pattern making. In this paper, we study the difference of the landmarks between the traditional method and 3D scanner and we also select the 19 circumference measurements,29 height and length measurements, 18 breadth and depth measurements and 3 other measurements, which are quite important in fashion body measuring, to compare the terminology of them in these two measuring method. 3D scanners seem better than the traditional method on these aspects, which are the number of measurements, speed,privacy and data accuracy, but they are limited on measuring posture. And there is no uniform standard for the scanners and the definitions of the measurements in the scanners are diversified.展开更多
By the sketch of structure of MVWG,the working laws of this kind of gyroscope we re explained.To the aid of Euler′s Dynamics Equation,a mathematical model of the gyroscope was constructed,and then by the basic workin...By the sketch of structure of MVWG,the working laws of this kind of gyroscope we re explained.To the aid of Euler′s Dynamics Equation,a mathematical model of the gyroscope was constructed,and then by the basic working laws of MVWG the model was simplified.Under the conditions of the three axial direction rotations and general rotation,the mathematical model was resolved.And finally by the solutions, the working laws of the gyroscope, the working disparity among all sorts of gyrations and the influences from the gyrations in the axial directions were analysed.展开更多
The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results...The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results in the phenomena of identical object with dissimilar spectrum and different objects with similar spectrum. In this paper, an integrated classification method that combines a decision tree with slope data, tasseled cap transformation indices and maximum likelihood classifier is introduced, to find an optimal classification method for thematic mapper imagery of plain and highland terrains. A Landsat 7 ETM+ image acquired over Hangzhou Bay, in eastern China was used to test the method. The results indicate that the performance of the inte- grated classifier is acceptably good in comparison with that of the existing most widely used maximum likelihood classifier. The integrated classifier depends on hypsography (variation in topography) and the characteristics of ground truth objects (plant and soil). It can greatly reduce the influence of the homogeneous spectrum caused by topographic variation. This integrated classifier might potentially be one of the most accurate classifiers and valuable tool for land cover and land use mapping of plain and highland terrains.展开更多
The aim of the study was to describe the binding of cholic acid by hemicellulose and pectin of yard-long bean at gastrointestinal system (in vitro), through variation of acidity (pH 3, 5 and 7) and boiling time (...The aim of the study was to describe the binding of cholic acid by hemicellulose and pectin of yard-long bean at gastrointestinal system (in vitro), through variation of acidity (pH 3, 5 and 7) and boiling time (raw/0, 5, 20 and 35 minutes) of yard-long bean. Two-way Anova (α= 5%) and functional groups analysis by infrared spectrophotometer were applied for the binding description. The results of the study showed: (1) The highest binding percentage of cholic acid by dietary fiber of yard-long bean at pH 3-raw treatment (76.603%); (2) Cholic acid binding via C = O/ester or acid of hemicellulose, C-O-C/cyclic ether of pectin, while C = O/ester or acid of oectin through iron.展开更多
A method of restoring scratches on old paintings is proposed,and the corresponding high-accuracy output workflow is also developed.Firstly the scanner is selected as an input device to get the RGB(red,green,blue)image...A method of restoring scratches on old paintings is proposed,and the corresponding high-accuracy output workflow is also developed.Firstly the scanner is selected as an input device to get the RGB(red,green,blue)image of the painting,and for the purpose of capturing high-quality image,scanner characterization is done by using neural network.And then the scratches on the RGB image are restored with the technology of digital inpainting,while the inpainting algorithm is mainly based on gradient vector and fast marching method.Finally the restored image is output with a printer,which is calibrated by using the high order polynomial regression method.In experiment the new replicated painting is well restored in the scratched areas,as well as keeps high resemblance with the original painting.展开更多
MEMS swallowable capsule is a novel technology in the non-invasive surgery. This technology provides a way to diagnose directly into the deep intestinal where the traditional invasive technology implemented, such as X...MEMS swallowable capsule is a novel technology in the non-invasive surgery. This technology provides a way to diagnose directly into the deep intestinal where the traditional invasive technology implemented, such as X-Ray, endoscopy. It is a key for us to locate and track the position of a MEMS capsule in clinical applications. To solve this problem, we implemented a magnetic sensor module based on the scalar form of the magnetic dipole model,which was designed with very small size (5.2 * 2. 1 * 1.2 em) and easy to assemble to satisfy the system requirement. Here we discuss in detail the principle of magnetic dipole model, rules of selecting sensor and functions of the module. Some trials are established to test the characteristic of the module. The results of the Cm experiment demonstrates that the module follows the rules of the new magnetic dipole model form.展开更多
Purpose: The aim of this study was to analyze and compare the effects of different sports(swimming, football, basketball, and handball) on fat mass and lean mass in prepubertal and pubertal girls.Methods: Two hundred ...Purpose: The aim of this study was to analyze and compare the effects of different sports(swimming, football, basketball, and handball) on fat mass and lean mass in prepubertal and pubertal girls.Methods: Two hundred girls(10.6 ± 1.5 years old, Tanner stages I–III) participated in the study and were divided into 5 groups: 40 swimmers, 40 football players, 40 basketball players, 40 handball players, and 40 controls. Fat and lean masses at whole body, arms, trunk, and legs were measured using dual-energy X-ray absorptiometry(DXA). Pubertal status was determined using Tanner test. Effects of different sports on fat and lean masses were assessed through analysis of covariance with height as covariates. Analyses were performed separately in 2 groups depending on the Tanner stage(prepubertal and pubertal).Results: The girls of the control group had less lean mass and more fat mass compared to the girls who play sports(p < 0.05). There were differences in body fat between sports. The swimmers and football players had less body fat(p < 0.05). On the other hand, handball players showed the highest values in lean mass(p < 0.05).Conclusion: Impact sports(football, basketball, and handball) and low-impact sports(swimming) provide an appropriate development of lean mass in growing girls. We can conclude that people practicing sports at early ages ensure a lower fat mass and higher lean mass compared to those who do not practice. These results may be useful as a preventive method of adult obesity.展开更多
Driven by the political upheavals in the Arab world, media in Egypt and in the United Arab Emirates (UAE) is on its way to find new ways about how to deal with their audiences. Initial signs suggest that Emirati as ...Driven by the political upheavals in the Arab world, media in Egypt and in the United Arab Emirates (UAE) is on its way to find new ways about how to deal with their audiences. Initial signs suggest that Emirati as well as Egyptian media have drawn some first findings from the upheavals of the "Arab Spring", so that the first flimsy form of media accountability and a new openness is to be found in the media orient. Moreover, this study tries to draw some parallels between the "old" Arab sphere (Egypt) and the "new" Arab world (UAE) in order to generate new knowledge exploratively. Twelve journalists and media professionals from both countries have been qualitatively interviewed between November 2011 and May 2012 in this regard at spot and via phone or skype. This study distinguishes between two different media systems within the Arab sphere. International comparative studies on the media systems within the heterogeneous world of Arabia are considered as a desideratum in the field of journalistic research.展开更多
Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplemen...Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplement, the Monte Carlo method, were used to estimate the uncertainty of task-specific laser tracker measurements. First, the sources of error in laser tracker measurement were analyzed in detail, including instruments, measuring network fusion, measurement strategies, measurement process factors(such as the operator), measurement environment, and task-specific data processing. Second, the GUM and Monte Carlo methods and their application to laser tracker measurement were presented. Finally, a case study involving the uncertainty estimation of a cylindricity measurement process using the GUF and Monte Carlo methods was illustrated. The expanded uncertainty results(at 95% confidence levels) obtained with the Monte Carlo method are 0.069 mm(least-squares criterion) and 0.062 mm(minimum zone criterion), respectively, while with the GUM uncertainty framework, none but the result of least-squares criterion can be got, which is 0.071 mm. Thus, the GUM uncertainty framework slightly underestimates the overall uncertainty by 10%. The results demonstrate that the two methods have different characteristics in task-specific uncertainty evaluations of laser tracker measurements. The results indicate that the Monte Carlo method is a practical tool for applying the principle of propagation of distributions and does not depend on the assumptions and limitations required by the law of propagation of uncertainties(GUF). These features of the Monte Carlo method reduce the risk of an unreliable measurement of uncertainty estimation, particularly in cases of complicated measurement models, without the need to evaluate partial derivatives. In addition, the impact of sampling strategy and evaluation method on the uncertainty of the measurement results can also be taken into account with Monte Carlo method, which plays a guiding role in measurement planning.展开更多
文摘Because the vector of angular momentum of ESG (electrostatically suspended gyroscope) maintains the fixed direction in inertial space, it may be regarded as a fixed star. The astronavigation aigorithm is used to estimate the azimuth angle and the gyro constant drift in the paper. The relative errors which affect the estimation accuracy of the azimuth angle are the analysed.
文摘Testing methods of instrumental system in the marine magnetic survey have been studied in this paper, and the feasibility of each method has been testified by the observed data. The conclusion shows that the method brought out can effectively eliminate the systematic error caused by the instrumental system, and greatly improve the surveying precision and the reliability of the survey results.
基金The Special Funds for State Key Projects for Fun- damental Research (G1999022201-04).
文摘Application of particle image velocity (PIV) techniques for measuringparticle size distribution and total number in an activation chamber of desulfurization system isintroduced. Watersheld algorithm is used to choose the suitable initial gray level threshold whichis used to change the gray level images taken by PIV to black and white ones, then every particle inan image is isolated totally. For every isolating particle, its contour is tracked by the edgeenhancement filter function and kept by Freeman s chain code. Based on a set of particle s chincode, its size and size distribution are calculated and sorted. Finally, the experimental data ofcalcium particles and water drops, separately injected into the activation chamber, and the erroranalysis of data are given out.
文摘According to the characteristics of gravity passive navigation, this paper presents a novel gravity passive navigation system (GPNS), which consists of the rate azimuth platform (RAP), gravity sensor, digitally stored gravity maps, depth sensor and relative log. The algorithm of rate azimuth platform inertial navigation system, error state-space equations, measurement equations and GPNS optimal filter are described. In view of the measurements made by an onboard gravity sensor the Eotvos effect is introduced in the gravity measurement equation of a GPNS optimal filter. A GPNS is studied with the Matlab/Simulink tools; simulation results demonstrate that a GPNS has small errors in platform attitude and position. Because the inertial navigation platform is the rate azimuth platform in the GPNS and gravity sensor is mounted on the rate azimuth platform, the cost of the GPNS is lower than existing GPNS's and according to the above results the GPNS meets the need to maintain accuracy navigation for underwater vehicles over long intervals.
文摘The cost of the gravity passive inertial navigation system will be lower witha rate azimuth platform and gravity sensor constituting a gravity measurement and navigationsystem. According to the system performance characteristics, we study the rate azimuth platforminertial navigation system (RAPINS), give the system navigation algorithm, error equations of theattitude, velocity and position of the rate azimuth platform, and random error models of theaccelerometer and gyro. Using the MATLAB/Simulink tools, we study the RAPINS and RAPINS withvelocity damping. Simulation results demonstrate that the RAPINS with velocity damping has smallerrors in platform attitude and position and satisfies gravity measurement and navigationrequirement.
基金The National Natural Science Foundation of China(No.61327803)
文摘In order to calibrate electrical instruments and generate a constant magnetic field, a novel design method for square Helmholtz coil is proposed. According to the superposition principle in electromagnetics, the theory of the square Helmholtz coil is established, and the design method is verified by Matlab calculation. Compared with conventional circular Helmholtz coil, the novel square one is with a larger uniform region. Simulation work is conducted in Maxwell, and the distribution of the magnetic field is obtained. The results demonstrate the validation of the applied calculation method of the proposed Helmholtz model. The space utilization rate η is used to make a comparison between the square and circular coils for the uniform region. The square Helmholtz coil is fabricated, the length of a single square coil is 1.5 m, and the amplitude of the magnetic field is controlled by the current. The GSM-19 T proton magnetometer is used to measure the amplitude of the magnetic field generated by the square Helmholtz coil. Experimental results indicate that a wide-range variable uniform magnetic field from 0 to 120 μT is generated in the center of Helmholtz coils.
基金Supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX1-YW-12)the National High Technology Research and Development Program of China (863 program) (No.2008AA09A401,No.2006AA09A109)
文摘Large amplitude internal solitary waves(ISWs) often exhibit highly nonlinear effects and may contribute significantly to mixing and energy transporting in the ocean.We observed highly nonlinear ISWs over the continental shelf of the northwestern South China Sea(19°35'N,112°E) in May 2005 during the Wenchang Internal Wave Experiment using in-situ time series data from an array of temperature and salinity sensors,and an acoustic Doppler current profiler(ADCP).We summarized the characteristics of the ISWs and compared them with those of existing internal wave theories.Particular attention has been paid to characterizing solitons in terms of the relationship between shape and amplitude-width.Comparison between theoretical prediction and observation results shows that the high nonlinearity of these waves is better represented by the second-order extended Korteweg-de Vries(KdV) theory than the first-order KdV model.These results indicate that the northwestern South China Sea(SCS) is rich in highly nonlinear ISWs that are an indispensable part of the energy budget of the internal waves in the northern South China Sea.
基金Supported by the NSF of the Higher Education Institutions of Jiangsu Province(10KJD110006)Supported by the grant of Jiangsu Institute of Education(Jsjy2009zd03)Supported by the Qing Lan Project of Jiangsu Province(2010)
文摘In this paper,we present the semi-implicit Euler(SIE)numerical solution for stochastic pantograph equations with jumps and prove that the SIE approximation solution converges to the exact solution in the mean-square sense under the Local Lipschitz condition.
基金supported by the National Natural Science Foundation of China(41473016)the State Key Laboratory of Geological Processes and Mineral Resources
文摘Here we report iron(Fe) isotopic data of three pure Fe solution standards(IRMM-014, GSB Fe, and NIST3126a) and five widely used geological reference materials(RMs) from the United States Geological Survey and Geological Survey of Japan obtained on a Neptune Plus multi-collector–inductively coupled plasma–mass spectrometer(MC-ICP-MS) in our laboratory over the past 3 years. The instrumental mass bias was corrected by three independent methods: sample-standard bracketing(SSB),Ni doping + SSB, and ^(57)Fe–^(58)Fe double spike + SSB.Measurements reveal that both the Ni doping and double spike methods helped calibrate short-term fluctuations in mass bias. Collectively, almost all measurements of RMs yielded δ^(56)Fe within ± 0.05 of recommended values,provided that each sample was measured four times on MC-ICP-MS. For the first time, new recommended values for NIST SRM3126a are reported(δ^(56)Fe = 0.363 ± 0.006,2SE, 95% CI; and δ^(57)Fe = 0.534 ± 0.010, 2SE).
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2013AA09A505)the National Science Foundation for Young Scientists of China(Nos.41306191,41306192,41321004,41406203)the Scientific Research Fund of the Second Institute of Oceanography,State Oceanic Administration of China(No.JG1317)
文摘This paper proposes a joint method to simultaneously retrieve wave spectra at dif ferent scales from spaceborne Synthetic Aperture Radar(SAR) and wave spectrometer data. The method combines the output from the two dif ferent sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coeffi cient is estimated using an ef fective signifi cant wave height(SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coeffi cient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as fi rst guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the joint method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length(PWL), and peak wave direction(PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR(ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting(ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed joint retrieval method could be a valuable complement to traditional methods used to retrieve directional ocean wave spectra, particularly in inhomogeneous sea states.
文摘Body measuring is very important for garment sizing and pattern making. In this paper, we study the difference of the landmarks between the traditional method and 3D scanner and we also select the 19 circumference measurements,29 height and length measurements, 18 breadth and depth measurements and 3 other measurements, which are quite important in fashion body measuring, to compare the terminology of them in these two measuring method. 3D scanners seem better than the traditional method on these aspects, which are the number of measurements, speed,privacy and data accuracy, but they are limited on measuring posture. And there is no uniform standard for the scanners and the definitions of the measurements in the scanners are diversified.
文摘By the sketch of structure of MVWG,the working laws of this kind of gyroscope we re explained.To the aid of Euler′s Dynamics Equation,a mathematical model of the gyroscope was constructed,and then by the basic working laws of MVWG the model was simplified.Under the conditions of the three axial direction rotations and general rotation,the mathematical model was resolved.And finally by the solutions, the working laws of the gyroscope, the working disparity among all sorts of gyrations and the influences from the gyrations in the axial directions were analysed.
文摘The classification of thematic mapper imagery in areas with strong topographic variations has proven problematic in the past using a single classifier, due to the changing sun illumination geometry. This often results in the phenomena of identical object with dissimilar spectrum and different objects with similar spectrum. In this paper, an integrated classification method that combines a decision tree with slope data, tasseled cap transformation indices and maximum likelihood classifier is introduced, to find an optimal classification method for thematic mapper imagery of plain and highland terrains. A Landsat 7 ETM+ image acquired over Hangzhou Bay, in eastern China was used to test the method. The results indicate that the performance of the inte- grated classifier is acceptably good in comparison with that of the existing most widely used maximum likelihood classifier. The integrated classifier depends on hypsography (variation in topography) and the characteristics of ground truth objects (plant and soil). It can greatly reduce the influence of the homogeneous spectrum caused by topographic variation. This integrated classifier might potentially be one of the most accurate classifiers and valuable tool for land cover and land use mapping of plain and highland terrains.
文摘The aim of the study was to describe the binding of cholic acid by hemicellulose and pectin of yard-long bean at gastrointestinal system (in vitro), through variation of acidity (pH 3, 5 and 7) and boiling time (raw/0, 5, 20 and 35 minutes) of yard-long bean. Two-way Anova (α= 5%) and functional groups analysis by infrared spectrophotometer were applied for the binding description. The results of the study showed: (1) The highest binding percentage of cholic acid by dietary fiber of yard-long bean at pH 3-raw treatment (76.603%); (2) Cholic acid binding via C = O/ester or acid of hemicellulose, C-O-C/cyclic ether of pectin, while C = O/ester or acid of oectin through iron.
基金"13115"Sci-Tech Innovation Programof Shaanxi Province,China(No.2008ZDKG39)Youth Foundation of Xi'an University of Technology,China(No.104210807)
文摘A method of restoring scratches on old paintings is proposed,and the corresponding high-accuracy output workflow is also developed.Firstly the scanner is selected as an input device to get the RGB(red,green,blue)image of the painting,and for the purpose of capturing high-quality image,scanner characterization is done by using neural network.And then the scratches on the RGB image are restored with the technology of digital inpainting,while the inpainting algorithm is mainly based on gradient vector and fast marching method.Finally the restored image is output with a printer,which is calibrated by using the high order polynomial regression method.In experiment the new replicated painting is well restored in the scratched areas,as well as keeps high resemblance with the original painting.
文摘MEMS swallowable capsule is a novel technology in the non-invasive surgery. This technology provides a way to diagnose directly into the deep intestinal where the traditional invasive technology implemented, such as X-Ray, endoscopy. It is a key for us to locate and track the position of a MEMS capsule in clinical applications. To solve this problem, we implemented a magnetic sensor module based on the scalar form of the magnetic dipole model,which was designed with very small size (5.2 * 2. 1 * 1.2 em) and easy to assemble to satisfy the system requirement. Here we discuss in detail the principle of magnetic dipole model, rules of selecting sensor and functions of the module. Some trials are established to test the characteristic of the module. The results of the Cm experiment demonstrates that the module follows the rules of the new magnetic dipole model form.
文摘Purpose: The aim of this study was to analyze and compare the effects of different sports(swimming, football, basketball, and handball) on fat mass and lean mass in prepubertal and pubertal girls.Methods: Two hundred girls(10.6 ± 1.5 years old, Tanner stages I–III) participated in the study and were divided into 5 groups: 40 swimmers, 40 football players, 40 basketball players, 40 handball players, and 40 controls. Fat and lean masses at whole body, arms, trunk, and legs were measured using dual-energy X-ray absorptiometry(DXA). Pubertal status was determined using Tanner test. Effects of different sports on fat and lean masses were assessed through analysis of covariance with height as covariates. Analyses were performed separately in 2 groups depending on the Tanner stage(prepubertal and pubertal).Results: The girls of the control group had less lean mass and more fat mass compared to the girls who play sports(p < 0.05). There were differences in body fat between sports. The swimmers and football players had less body fat(p < 0.05). On the other hand, handball players showed the highest values in lean mass(p < 0.05).Conclusion: Impact sports(football, basketball, and handball) and low-impact sports(swimming) provide an appropriate development of lean mass in growing girls. We can conclude that people practicing sports at early ages ensure a lower fat mass and higher lean mass compared to those who do not practice. These results may be useful as a preventive method of adult obesity.
文摘Driven by the political upheavals in the Arab world, media in Egypt and in the United Arab Emirates (UAE) is on its way to find new ways about how to deal with their audiences. Initial signs suggest that Emirati as well as Egyptian media have drawn some first findings from the upheavals of the "Arab Spring", so that the first flimsy form of media accountability and a new openness is to be found in the media orient. Moreover, this study tries to draw some parallels between the "old" Arab sphere (Egypt) and the "new" Arab world (UAE) in order to generate new knowledge exploratively. Twelve journalists and media professionals from both countries have been qualitatively interviewed between November 2011 and May 2012 in this regard at spot and via phone or skype. This study distinguishes between two different media systems within the Arab sphere. International comparative studies on the media systems within the heterogeneous world of Arabia are considered as a desideratum in the field of journalistic research.
基金Project(51318010402)supported by General Armament Department Pre-Research Program of China
文摘Measurement uncertainty plays an important role in laser tracking measurement analyses. In the present work, the guides to the expression of uncertainty in measurement(GUM) uncertainty framework(GUF) and its supplement, the Monte Carlo method, were used to estimate the uncertainty of task-specific laser tracker measurements. First, the sources of error in laser tracker measurement were analyzed in detail, including instruments, measuring network fusion, measurement strategies, measurement process factors(such as the operator), measurement environment, and task-specific data processing. Second, the GUM and Monte Carlo methods and their application to laser tracker measurement were presented. Finally, a case study involving the uncertainty estimation of a cylindricity measurement process using the GUF and Monte Carlo methods was illustrated. The expanded uncertainty results(at 95% confidence levels) obtained with the Monte Carlo method are 0.069 mm(least-squares criterion) and 0.062 mm(minimum zone criterion), respectively, while with the GUM uncertainty framework, none but the result of least-squares criterion can be got, which is 0.071 mm. Thus, the GUM uncertainty framework slightly underestimates the overall uncertainty by 10%. The results demonstrate that the two methods have different characteristics in task-specific uncertainty evaluations of laser tracker measurements. The results indicate that the Monte Carlo method is a practical tool for applying the principle of propagation of distributions and does not depend on the assumptions and limitations required by the law of propagation of uncertainties(GUF). These features of the Monte Carlo method reduce the risk of an unreliable measurement of uncertainty estimation, particularly in cases of complicated measurement models, without the need to evaluate partial derivatives. In addition, the impact of sampling strategy and evaluation method on the uncertainty of the measurement results can also be taken into account with Monte Carlo method, which plays a guiding role in measurement planning.