Short-duration transient visual evoked potentials and color reflectivity discretization analysis in glaucoma patients and suspects

AIM： To evaluate the use of short-duration transient visual evoked potentials（VEP） and color reflectivity discretization analysis（CORDA） in glaucomatous eyes,eyes suspected of having glaucoma,and healthy eyes.METHODS： The study included 136 eyes from 136 subjects： 49 eyes with glaucoma,45 glaucoma suspect eyes,and 42 healthy eyes.Subjects underwent Humphrey visual field（VF） testing,VEP testing,as well as peripapillary retinal nerve fiber layer optical coherence tomography imaging studies with post-acquisition CORDA applied.Statistical analysis was performed using means and ranges,ANOVA,post-hoc comparisons using Turkey＇s adjustment,Fisher＇s Exact test,area under the curve,and Spearman correlation coefficients.RESULTS： Parameters from VEP and CORDA correlated significantly with VF mean deviation（MD）（P〈0.05）.In distinguishing glaucomatous eyes from controls,VEP demonstrated area under the curve（AUC） values of 0.64-0.75 for amplitude and 0.67-0.81 for latency.The CORDA HR1 parameter was highly discriminative for glaucomatous eyes vs controls（AUC=0.94）.CONCLUSION： Significant correlations are found between MD and parameters of short-duration transient VEP and CORDA,diagnostic modalities which warrant further consideration in identifying glaucoma characteristics.

Tensor discriminant dictionary classification method for prestack seismic reflection patterns

The existing seismic reflection pattern classification methods need to convert multidimensional prestack seismic data into one-dimensional vectors for processing,which loses the characteristics of amplitude variation with offset/azimuth in the prestack seismic data.In this study,a tensor discriminant dictionary learning method for classifying prestack seismic reflection patterns is proposed.The method is initially based on the tensor Tucker decomposition algorithm and uses a tensor form to characterize the prestack seismic data with multidimensional features.The tensor discriminant dictionary is then used to reduce the influence of noise on the sample features.Finally,the method uses the Pearson correlation coefficient to measure the correlation degree of the sparse representation coefficients of different types of tensors.The advantages of the new method are as follows.(1)It can retain the rich structural features in different dimensions in the prestack data.(2)It adjusts the threshold of the Pearson correlation coefficient to optimize the classification effect.(3)It fully uses drilling information and expert knowledge and performs calibration training of the sample labels.The numerical-model tests confirm that the new method is more accurate and robust than the traditional support vector machine and K-nearest neighbor classification algorithms.The application of actual data further confirms that the classification results of the new method agree with the geological patterns and are more suitable for the analysis and interpretation of sedimentary facies.

SMONTE CARLO CALCULATION FOR CALIBRATION FUNCTIONS IN TOTAL REFLECTION X-RAY FLUORESCENCE SPECTROMETRY

Simulation approach includes such processes as photon emissions from X-ray tube with a spectral distribution, total reflection on the sample support, photoelectric effect in thin layer sample, as well as characteristic line absorption and detection. The calculation results are in agreement with experimental ones.

Investigation on Physiological Status of Regional Vegetation Using Pushbroom Hyperspectral Imager Data

To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field.

Seismic Microzonation of Mandalay City, Myanmar

Understanding the parameters of PGA （peak ground acceleration） is very important for seismic hazard mitigation and environmental planning in Mandalay City, Myanmar. In this study, fifty SPTs （Standard Penetration Tests） measurement data were collected in Mandalay City, for calculating average shear velocity Vs30, which will be used in seismic microzonation mapping. The shear wave velocity Vs30 of the top layer is Vs30 〈 220 m/s. The ground motion characteristic was estimated by means of the predominant periods and linear magnification factors obtained using the multiple reflection analysis. The highest potential zone of seismic hazard mostly locates the north western marginal part of Mandalay city, in the proximal portion to the dextral Sagaing fault.

Scientific Investigation of the Paintings from the Agarbiciu (Cluj County) Wooden Church

The investigation of the painting materials (pigments, binders and varnish) of Agarbiciu wooden church painted walls was done by employing both nondestructive (XRF and reflection FTIR spectroscopy for pigments) and destructive methods (FTIR spectroscopy and GC-MS spectrometry for pigments and binders). The digital restoration of the interior of the wooden church was done using the physical-chemical composition of the painting layer, a metadata set that describes the timeline, detailed photographic documentation and the 3D scanned interior of the church.

Uncertainty analysis of a pavement reflectance measurement system based on a gonio-photometer

A pavement reflectance measurement system is established based on a gonio-photometerexisting by chang- ing a bracket to carry the road sample and luminance meter, adding a collimated light source to provide incident light. This automated system could finish the reflection measurement of a road sample in 4 h. An uncertainty budget of this measurement system is made and the combined standard uncertainty of Q0 is 5.26%.