NDVI changes in China between 1989 and 1999 using change vector analysis based on time series data

Change vector analysis (CVA) and principal component analysis in NDVI time-trajectories space are powerful tools to analyze land-cover change. The magnitude of the change vector indicates amplitude of the change, while its direction indicates the nature of the change. CVA is applied to two remotely sensed indicators of land surface conditions, NDVI and spatial structure, in order to improve the capability to detect and categorize land-cover change. The magnitude and type of changes are calculated in China from 1989 to 1999. Through the research, the main conclusions are drawn as follows: 1) The changes of NDVI are quite different between eastern China and western China, and the change range in the east is bigger than that in the west. The trend in NDVI time series is smoothly increasing, the increases happen mostly in Taiwan, Fujian, Sichuan and Henan provinces and the decreases occur in Yunnan and Xinjiang. 2) The spatial structure index can indicate changes in the seasonal ecosystem dynamics for spatially heterogeneous landscapes. Most of spatial structure changes, which occurred in southern China, correlated with vegetation growth processes and strike of mountains.

Independent Vector Analysis Based Blind Interference Reduction and Signal Recovery for MIMO IoT Green Communications

In application to time convolutive mixing model or frequency domain blind separation model for wireless receiving applications,frequency domain independent component analysis(FDICA)has been a very popular method but with adverse random permutation ambiguity influence.In order to solve this inherent problem in FDICA assisted multiple-input multiple-output orthogonal frequency-division multiplexing(MIMO-OFDM)based the Internet of Thing(IoT)systems,this paper proposes an new detection mechanism,named independent vector analysis(IVA),for realizing blind adaptive signal recovery in MIMO IoT green communication to reduce inter-carrier interference(ICI)and multiple access interference(MAI).IVA jointly implements separation work for different frequency bin data while the FDICA deals with it separately.In IVA,the dependencies of frequency bins can be exploited in mitigating the random permutation problem.In addition,multivariate prior distributions are employed to preserve the inter-frequency dependencies for individual sources,which can result in separation performance enhancement.Simulation results and analysis corroborate the effectiveness of the proposed method.

Vector analysis of Contoura Vision for the correction of myopia and myopic astigmatism

AIM: To evaluate the visual outcomes of Contoura Vision(CV) with automatic eye tracking system in eyes with myopia and myopic astigmatism.METHODS: This prospective study included 160 eyes(80 patients) with moderate myopia and irregular astigmatism between January and August 2018. Subjects were randomly divided into CV group(80 eyes) that under went CV femtosecond laser-assisted in situ keratomileusis(FS-LASIK) and a control group(80 eyes) that underwent wavefrontoptimized FS-LASIK. Visual outcomes and astigmatic vector analysis were evaluated and compared between preoperatively and 3 mo postoperatively. RESULTS: Basic details were similar in both groups(P>0.05). At 3 mo postoperatively, uncorrected distance visual acuity was 20/16, 20/20, and 20/25 in 24, 76, and 80 eyes of patients in CV group, respectively. The CV group was better in predictability of astigmatism correction at 3 mo postoperatively. In CV group, 64 eyes had deviation of astigmatic axis within 15° and 28 eyes had deviation of astigmatic axis within 5°, both were better than those in the control group. The number of eyes with residual astigmatism within 0.5 D were less in CV group(48 eyes) than the control group(40 eyes). Compared with the preoperative, C7 significantly reduced to 0.056±0.030 in CV group at 3 mo after the procedure(P<0.05), and were significantly lower than those in the control group(P<0.05).CONCLUSION: CV with automatic eye tracking system is safe and effective for the correction of myopia and myopic astigmatism.

Bioelectrical impedance vector analysis evaluates cellularity and hydration in cirrhotic patients

BACKGROUND Malnutrition in cirrhotic patients is correlated with mortality and a better response to liver transplantation.However,recovery of the nutritional status in these patients is a challenge due to the difficulty in establishing a reliable nutritional diagnosis.The bioelectrical impedance vector analysis(BIVA)method appears as a feasible tool in clinical practice to define the physiological state of cirrhotic patients by assessing hydration and body cellularity.AIM To evaluate body composition in cirrhotic patients using BIVA.METHODS This retrospective cross-sectional study was carried out by following cirrhotic outpatients at a hospital in Porto Alegre,Brazil.A tetrapolar bioelectrical impedance analysis device was used to evaluate cellularity and hydration and to perform the BIVA.The BIVA graphic was elaborated by software and for statistical analysis a significance level of 5%(P≤0.05)was considered.RESULTS One hundred and ninety patients,61.1%males,with a mean age of 56.6±11.0 years,were evaluated.Of these,56.3%had Child-Turcotte-Pugh(CTP)A score,and the prevalent etiology was hepatitis C virus(47.4%).The patients were classified according to cellularity and hydration by the quadrants and ellipses of the BIVA method,quadrant 1(47.9%);quadrant 2(18.9%);quadrant 3(14.2%);and quadrant 4(18.9%).Those classified in quadrant 1 and 2 had a higher phase angle compared to those in quadrants 3 and 4(P<0.001).Quadrant 2 patients had a lower average age than the other groups.The association with CTP score showed that patients in quadrant 2 had a higher proportion of CTP A,and those in quadrant 4 had a higher proportion of CTP C(P<0.052).CONCLUSION The BIVA method allows identification of the cellularity and hydration status of cirrhotic patients,and its association with clinical factors determines the disease severity,age and prognostic index.

Surgically induced astigmatismCorneal astigmatismMeanSummated vector meanCentroidVector analysisTemporal incisionSuperior incisionICL implantation

BackgroundTo compare the arithmetic mean (M-SIA) and the summated vector mean of surgically induced astigmatism (SVM-SIA) according to the incision site after phakic intraocular lens (Visian implantable collamer lens (ICL), STAAR Surgical) implantation.MethodsThis study comprised 121 eyes of 121 consecutive patients undergoing ICL surgery through a 3.0-mm temporal or superior clear corneal incision. The magnitude and the axis of corneal astigmatism preoperatively and 3 months postoperatively were measured using an automated keratometer. The M-SIA and the SVM-SIA were determined according to the incision site.ResultsThe magnitude of corneal astigmatism significantly increased from 1.23 ± 0.59 D preoperatively to 1.46 ± 0.72 D postoperatively in the temporal incision group (Wilcoxon signed-rank test, P < 0.001), but it significantly decreased from 1.09 ± 0.36 D preoperatively to 0.86 ± 0.41 D postoperatively in the superior incision group (P < 0.001). The M-SIA was 0.48 ± 0.30 D, and the SVM-SIA was 0.23 ± 0.52 D at a meridian of 82° in the temporal incision group. The M-SIA was 0.57 ± 0.30 D, and the SVM-SIA was 0.47 ± 0.45 D at a meridian of 1° in the superior incision group.ConclusionsICL implantation induces the M-SIA by approximately 0.5 D, but the SVM-SIA decreased to 50% and 80% of the M-SIA in magnitude through temporal and superior incisions, respectively. The direction of the SVM-SIA showed a tendency toward corneal flattening to the incisional site. It should be noted that the M-SIA is somewhat different from the SVM-SIA according to the incision site.

Q Vector Analysis of Torrential Rainfall from Meiyu Front Cyclone:A Case Study

Following similar derivation of quasi-geostrophic Q vector （Q^C）, a new Q vector （Q^N） is constructed in this study. Their difference is that the geostrophic wind in quasi-geostrophic Q vector is replaced by the wind in Q^N vector. The diagnostic analysis of Q^N vector is compared with that of Q^G vector in the case study of a typical Meiyu front cyclone （MYFC） occurred over Changjiang-Huaihe regions during 5-6 July 1991. The results show that the Q^N vector has more diagnostic advantages than Q^G vector does. Convergence of Q^N vector at 700 hPa is found to be a good indicator to mimic the horizontal distribution of precipitation. Q^N vector is further partitioned into four components： Q^Nalst （along-stream stretching）,Q^Ncurv （curvature）,Q^Nshdv （shear advection）, and Q^Ncrst （cross-stream stretching） in a natural coordinate system with isohypse （PG partitioning）. The application of Q^N PG partitioning in the MYFC torrential rain indicates that PG partitioning of Q can identify dominant physical processes. The horizontal distribution of 2V·Q^Nalst is similar to that of 2V·Q^N and mainly accounts for 2V·Q^N during the entire period of Meiyu. The effects of Q^Ncurv on rainfall enhancement fade from the mature stage to decay stage. Qshdv enhances precipitation significantly as the MYFC develops, and the effect weakens rapidly when the MYFC decays during its eastward propagation. Q^Ncrst shows little impacts on rainfall during the onset and mature phases whereas it displays significant role during the decay phase.Q^N alst and Q^Nshdv and Q^Ncrst show cancellation only during the decay period.

Slope stability analysis under seismic load by vector sum analysis method

The vibration characteristics and dynamic responses of rock and soil under seismic load can be estimated with dynamic finite element method （DFEM）. Combining with the DFEM, the vector sum analysis method （VSAM） is employed in seismic stability analysis of a slope in this paper. Different from other conventional methods, the VSAM is proposed based on the vector characteristic of force and current stress state of the slope. The dynamic stress state of the slope at any moment under seismic load can he obtained by the DFEM, thus the factor of safety of the slope at any moment during earthquake can be easily obtained with the VSAM in consideration of the DFEM. Then, the global stability of the slope can be estimated on the basis of time-history curve of factor of safety and reliability theory. The VSAM is applied to a homogeneous slope under seismic load. The factor of safety of the slope is 1.30 under gravity only and the dynamic factor of safety under seismic load is 1.21. The calculating results show that the dynamic characteristics and stability state of the slope with input ground motion can be actually analyzed. It is believed that the VSAM is a feasible and practical approach to estimate the dynamic stability of slopes under seismic load.

LS-SVM and Monte Carlo methods based reliability analysis for settlement of soft clayey foundation

A method which adopts the combination of least squares support vector machine（LS-SVM） and Monte Carlo（MC） simulation is used to calculate the foundation settlement reliability.When using LS-SVM,choosing the training dataset and the values for LS-SVM parameters is the key.In a representative sense,the orthogonal experimental design with four factors and five levels is used to choose the inputs of the training dataset,and the outputs are calculated by using fast Lagrangian analysis continua（FLAC）.The decimal ant colony algorithm（DACA） is also used to determine the parameters.Calculation results show that the values of the two parameters,and δ2 have great effect on the performance of LS-SVM.After the training of LS-SVM,the inputs are sampled according to the probabilistic distribution,and the outputs are predicted with the trained LS-SVM,thus the reliability analysis can be performed by the MC method.A program compiled by Matlab is employed to calculate its reliability.Results show that the method of combining LS-SVM and MC simulation is applicable to the reliability analysis of soft foundation settlement.

Growth and nutrient dynamics of Betula alnoides seedlings under exponential fertilization

Betula alnoides is a fast-growing hardwood species grown in large plantations in Southeast Asia and South China.Nitrogen requirements for producing robus seedlings,growth and nutrient dynamics were investigated using exponential fertilization treatments.Root collar diameter,height,dry mass and nutrient contents of seedlings increased exponentially in all fertilization treatments as time progressed.Moreover,with water soluble fertilizer（Plant Products plus microelements N–P2O5–K2O：20–20–20）,300 mg N seedling-1was adequate.Vector analysis revealed that P was the most responsive nutrient element followed by N and K.Dilutions of N and K were evident in the plants without N addition,which induced initial P sufficiency and then luxury consumption probably due to the antagonistic interaction between N and P.However deficiencies of N,P and K were mostly observed in al exponential regimes during the experiment because seedling growth rate exceeded nutrient uptake rate,inferring that further study on improving the nutrient uptake efficiency is needed.Analysis of relationships among nutrient supply,dry mass,N content and N concentration demonstrated that 100–400 mg N seedling-1induced sufficiency to luxury consumption of nitrogen without significant change in dry mass,and 400 mg N seedling-1is recommended to apply for nutrient loading of seedlings before outplanting.The findings will help improve seedling quality and enhance the production of robust seedlings for plantation forestry of this species.

GRINDING OF DOUBLE DISC GRINDING MACHINE

The grinding of two parallel sides of a component is accomplished with theaccuracy and higher productivity by passing a blank through the truncated cone shape grinders, whichare turned angles. The machine is designated by the name of double disc grinding machine (DDGM).Usually, it is used in the mass production. The relationship between these angles, the accuracy,productivity, allowance and parameters of the machine and technology is explained in detail by math,such as vector analysis, transformation of 3D space coordinates, etc. Therefore, in the aspects ofqualitative and quantitative analyses, the grinding potential of DDGM is enormous increased andsuperior to conventional methods. Furthermore, the theoretical foundation of DDGM grinding designand technology is provided to improve, to expand and to create for future. The established machinedesign and practical experience of grinding technology will get great benefit by them.

Single-step transepithelial photorefractive keratectomy in high myopia：qualitative and quantitative visual functions

AIM：To investigate quantitative and qualitative optical outcomes of single-step transepithelial photorefractive keratectomy（Trans PRK）in high myopia.METHODS：In a prospective interventional case-series,30 eyes with high myopia（-6.00 to-8.75 D）with（up to-3.00 D）or without astigmatism were enrolled from Bina Eye Hospital,Tehran,Iran. One-step Trans PRK was performed with aberration-free aspherical optimized profile and SCHWIND AMARIS 500 laser. One-year follow-up results for refraction,visual acuities,vector analysis,ocular wavefront（OWF）and corneal wave-front（CWF）higher order aberrations（HOA）,contrast sensitivity（CS）,and postoperative haze were assessed.RESULTS：After the surgery,both photopic and mesopic CSs significantly improved（both P〈0.001）. We detected significant induction of OWF coma and trefoil（P〈0.001 for both）HOAs; CWF coma（P=0.002）,spherical（P〈0.001）,and tetrafoil（P=0.003）HOAs in 6 mm analysis diameter; and CWF trefoil（P=0.04）HOA in 4 mm analysis diameter. The range of mean induction observed for various HOAs was0.005-0.11 μm. The 86.7% of eyes reached an uncorrected distance visual acuity of 20/20 or better; 96.7% of eyes were within ±0.5 D of targeted spherical refraction. In vector analysis,mean correction index value was 1.03 and mean index of success was 0.22. By 12mo after the operation,no eye lost any number of corrected distancevisual acuity lines. We detected no corneal haze greater than 1~＋ throughout the follow-up.CONCLUSION：Our findings show promising effects of single-step Trans PRK on quality of vision in high myopic eyes. It also improves refraction and visual acuity.

Validity of automated refraction after segmented refractive multifocal intraocular lens implantation

AIM： To evaluate the clinical utility of automated refraction（AR） and keratometry（KR） compared with subjective or manifest refraction（MR） after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X（Oculentis GmbH） refractive multifocal intraocular lens（IOL）.METHODS： Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3 mo follow-up.RESULTS： Analysis showed excellent repeatability of the AR measurements. Linear regression of AR versus MR showed good correlation for sphere and spherical equivalent, whereas the correlation for astigmatism was low. The mean difference AR-MR was-1.28±0.29 diopters（D） for sphere. Astigmatism showed better correlation between KR and MR. CONCLUSION： We suggest AR sphere plus 1.25 D and the KR cylinder as the starting point for MR in eyes with a Lentis Mplus X multifocal IOL. If AR measurements are equal to MR, decentration of the IOL should be suspected.

Nitrogen retranslocation, allocation, and utilization in bare root Larix olgensis seedlings

We quantified biomass accumulation and nitrogen （N） re- translocation, allocation, and utilization of Changbai larch （Larix olgen- sis） seedlings subjected to four fertilization treatments （24, 59, 81, 117 kg.ha-1 N） with an unfertilized control during summer and autumn 2009. Ammonium phosphate （18-46-0） was the fertilizer used in all treatments. On both sampling dates, the needles had greater biomass and N content than new （2009） stems and old （2008） stems, and coarse, medium and fine roots （diameters of 〉5, 2-5 mm, and 0-2 mm, respectively）. Higher N concentration was observed in old stems and coarse roots than that in new stems and medium roots. In mid-summer, fine roots had higher N concentration than coarse roots. The treatment with 24 kg.ha1 N had the greatest biomass and N content in needles and old stems, and highest net N retranslocation （NRA） and amount of N derived from soil. On Sep- tember 21, no N translocation was observed, while the treatment with 24 kg.ha^-1 N had the highest N utilization efficiency and fertilizer efficiency. Vector analysis revealed that all four fertilization treatments induced Nexcess relative to the control. The treatments with 59, 81, 117 kg.ha^-1 N induce N excess compared with treatments at 24 kg.ha-1 N. We conclude that the traditional local fertilizer application rates exceeded N require- ments and N uptake ability for Changbai larch seedlings. The application rate of 24 kg.ha^-1 N is recommended.

Topographically derived subpixel-based change detection for monitoring changes over rugged terrain Himalayas using AWiFS data

Continuous and accurate monitoring of earth surface changes over rugged terrain Himalayas is important to manage natural resources and mitigate natural hazards.Conventional techniques generally focus on per-pixel based processing and overlook the sub-pixel variations occurring especially in case of low or moderate resolution remotely sensed data.However,the existing subpixel-based change detection(SCD)models are less effective to detect the mixed pixel information at its complexity level especially over rugged terrain regions.To overcome such issues,a topographically controlled SCD model has been proposed which is an improved version of widely used per-pixel based change vector analysis(CVA)and hence,named as a subpixel-based change vector analysis(SCVA).This study has been conducted over a part of the Western Himalayas using the advanced wide-field sensor(AWiFS)and Landsat-8 datasets.To check the effectiveness of the proposed SCVA,the cross-validation of the results has been done with the existing neural network-based SCD(NN-SCD)and per-pixel based models such as fuzzybasedCVA(FCVA)andpost-classification comparison(PCC).The results have shown that SCVA offered robust performance(85.6%-86.4%)as comparedtoNN-SCD(81.6%-82.4%),PCC(79.2%-80.4%),and FCVA(81.2%-83.6%).We concluded that SCVA helps in reducing the detection of spurious pixels and improve the efficacy of generating change maps.This study is beneficial for the accurate monitoring of glacier retreat and snow cover variability over rugged terrain regions using moderate resolution remotely sensed datasets.

What Causes China's High Inflation? A Threshold Structural Vector Autoregression Analysis

China＇s astonishing economic growth implies a necessity to understand its inflation. The present paper employs threshold nonrecursive structural vector autoregression analysis to explore the asymmetric effects of macro-variables on inflation in low and high inflation regimes. The empirical evidence demonstrates, first, that the reactions of inflation to various shocks are inflation-regime-dependent and asymmetric. Second, monetary policy influences China ＂s high inflation and adjusting the domestic interest rate in China may be an effective way to control inflation in a high inflation regime, but not in a low inflation regime. In a high inflation regime, a high inflation rate may cause the macro-policy authorities to increase the domestic interest rate, in an attempt to stabilize high inflation. Third, contrary to expectations, the world oil price is not a strong cost-push factor in a low inflation regime. Oil price increases may increase inflation in a high inflation regime, but there is no such obvious effect in a low inflation regime. Finally, China ＂s nominal effective exchange rate influences inflation in both low and high inflation regimes. A nominal effeetive exchange rate appreciation might be effective in controlling domestic inflation in both regimes.

Probabilistic Methods in Multi-Class Brain-Computer Interface

Abstract-Two probabilistic methods are extended to research multi-class motor imagery of brain-computer interface （BCI）： support vector machine （SVM） with posteriori probability （PSVM） and Bayesian linear discriminant analysis with probabilistic output （PBLDA）. A comparative evaluation of these two methods is conducted. The results shows that： 1） probabilistie information can improve the performance of BCI for subjects with high kappa coefficient, and 2） PSVM usually results in a stable kappa coefficient whereas PBLDA is more efficient in estimating the model parameters.

Comparison of magnitude and summated vector mean of surgically induced astigmatism vector according to incision site after phakic intraocular lens implantation

Background:To compare the arithmetic mean(M-SIA)and the summated vector mean of surgically induced astigmatism(SVM-SIA)according to the incision site after phakic intraocular lens(Visian implantable collamer lens(ICL),STAAR Surgical)implantation.Methods:This study comprised 121 eyes of 121 consecutive patients undergoing ICL surgery through a 3.0-mm temporal or superior clear corneal incision.The magnitude and the axis of corneal astigmatism preoperatively and 3 months postoperatively were measured using an automated keratometer.The M-SIA and the SVM-SIA were determined according to the incision site.Results:The magnitude of corneal astigmatism significantly increased from 1.23±0.59 D preoperatively to 1.46±0.72 D postoperatively in the temporal incision group(Wilcoxon signed-rank test,P<0.001),but it significantly decreased from 1.09±0.36 D preoperatively to 0.86±0.41 D postoperatively in the superior incision group(P<0.001).The M-SIA was 0.48±0.30 D,and the SVM-SIA was 0.23±0.52 D at a meridian of 82°in the temporal incision group.The M-SIA was 0.57±0.30 D,and the SVM-SIA was 0.47±0.45 D at a meridian of 1°in the superior incision group.Conclusions:ICL implantation induces the M-SIA by approximately 0.5 D,but the SVM-SIA decreased to 50%and 80%of the M-SIA in magnitude through temporal and superior incisions,respectively.The direction of the SVM-SIA showed a tendency toward corneal flattening to the incisional site.It should be noted that the M-SIA is somewhat different from the SVM-SIA according to the incision site.

Why are Nitrogen Concentrations in Plant Tissues Lower under Elevated CO_2? A Critical Examination of the Hypotheses

Plants grown under elevated atmospheric [CO2] typically have decreased tissue concentrations of N compared with plants grown under current ambient [CO2]. The physiological mechanisms responsible for this phenomenon have not been definitely established, although a considerable number of hypotheses have been advanced to account for it. In this review we discuss and critically evaluate these hypotheses. One contributing factor to the decreases in tissue N concentrations clearly is dilution of N by increased photosynthetic assimilation of C. In addition, studies on intact plants show strong evidence for a general decrease in the specific uptake rates （uptake per unit mass or length of root） of N by roots under elevated CO2. This decreased root uptake appears likely to be the result both of decreased N demand by shoots and of decreased ability of the soil-root system to supply N. The best-supported mechanism for decreased N supply is a decrease in transpiration-driven mass flow of N in soils due to decreased stomatal conductance at elevated CO2, although some evidence suggests that altered root system architecture may also play a role. There is also limited evidence suggesting that under elevated CO2, plants may exhibit increased rates of N loss through volatilization and/or root exudation, further contributing to lowering tissue N concentrations.

Taxonomic and phylogenetic composition show biotic resistance to exotic invasion in acid seep springs

Background:Few studies have incorporated the evolutionary insights provided by analysis of phylogenetic structure along with community composition to assess the effects of exotic invasion on freshwater wetlands.Here,we assess the taxonomic and phylogenetic relationships among acid seep springs to investigate the potential homogenization or resistance of communities due to invasion of an exotic grass.Results:Multivariate community analyses indicated differences in community and phylogenetic composition and dispersion among acid seep springs,associated with gradients in soil moisture,canopy cover,and phylogenetic diversity.By contrast,univariate analyses showed differences in taxonomic diversity but not phylogenetic diversity among acid seep springs.Conclusions:Despite exotic invasion,individual acid seep springs remained taxonomically and phylogenetically distinct from each other.Taxonomic and phylogenetic diversity metrics revealed different aspects of composition,reinforcing the importance of including both in analyses of plant communities for understanding community assembly following exotic invasion and for management purposes.Within acid seep springs,taxonomic and phylogenetic composition appear to be driven more through environmental filtering by light and moisture than by the competitive effects following invasion of an exotic grass in support of Elton’s biotic resistance hypothesis.