42,395 research outputs found

    Nonlinearities in Conservative Growth Equations

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    Using the dynamic renormalization group (DRG) technique, we analyze general nonlinearities in a conservative nonlinear growth equation with non-conserved gaussian white noise. We show that they fall in two classes only: the Edwards-Wilkinson and Lai-Das Sarma types, by explicitly computing the associated amputated two and three point functions at the first order in perturbation parameter(s). We further generalize this analysis to higher order nonlinearities and also suggest a physically meaningful geometric interpretation of the same.Comment: REVTEX, will appear in Phys Rev E Rapid Comm. February 1996, .ps figure file available upon request to [email protected]

    Conference on immigration law and policies.

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    Conference held on 24 February 2001 (Saturday) in Council Chamber, 8/F, Meng Wah Complex, University of Hong Kong.Caption title.published_or_final_versionStrugging with the right to family life Athena Liu Liu, AthenaIntegration or segregation : the political attitude of new arrivals Robert Chung Chung, RobertHousing and welfare services for new arrivals from China : inclusion or exclusion? Ernest Chui Chui, ErnestImmigration and health care Chow Chun Bong Chow, Chun- bongQuota system and one way permit Ho Hei Wah Ho, Hei-wahDiscretion and immigration control Philip Dykes SC Dykes, Philip S. C.Immigration law and discretionary powers T K Lai Lai, T. K.Inherent contradictions and inconsistencies in the Immigration Ordinance S H Kwok Kwok, S. H.Due process and aliens Paul Harris Harris, PaulThe cultural politics of mainland Chinese migration to Hong Kong Khun Eng Kuah-Pearce Kuah-Pearce, Khun En

    Flying-capacitor multilevel converter voltage balance dynamics for pure resistive load

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    Multilevel converters need voltage balancing to be able to generate an output voltage with high quality. Flying capacitor converter topology has a natural voltage balancing property. Voltage balance dynamics analytical research methods reported to date are essentially based on a frequency domain analysis using double fourier transform. These complicated methods are not truly analytical, which makes an understanding of parameter influence on time constants difficult. In this paper, a straightforward time domain approach based on stitching of switch intervals piece-wise analytical solutions to a DC modulated H-bridge flying capacitor converter is discussed. This method allows to obtain time-averaged discrete and continuous voltage balance dynamics models. Using small-parameter approximation for pure resistive loads, simple and accurate expressions for voltage balance time constants are deduced, revealing their dependence on load parameters, carrier frequency and duty ratio

    The Sentinel-2 MSI Can Increase the Temporal Resolution of 30m Satellite-Derived LAI Estimates

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    The successful launch of the European Space Agency (ESA) Sentinel-2A (S2-A) on 23 June 2015 with its MultiSpectral Instrument (MSI) provides an important means to augment Earth-observation capabilities following the legacy of Landsat. After the three-month satellite commissioning campaign, the MSI onboard S-2A is performing very well (ESA, 2015). By 3 December 2015, the sensor data records have achieved provisional maturity status and have been accessed in level-1C Top-Of-Atmosphere (TOA) reflectance by the remote sensing community worldwide. Near-nadir observations by the MSI onboard S-2A and the Operational Land Imager (OLI) onboard Landsat 8 were collected during Simultaneous Nadir Overpasses as well as nearly coincident overpasses. This paper presents a processing chain using harmonized S-2A MSI and Landsat 8 OLI sensors to obtain increased temporal resolution in Leaf Area Index (LAI) estimates using the red-edge band B8A of MSI to replace the NIR band B08. Results demonstrate that LAI estimates from the MSI and OLI are comparable, and, given sufficient preprocessing for atmospheric correction and geometric rectification, can be used interchangeably to improve the frequency with which low LAI canopies can be monitored

    Vegetation indices mapping for Bhiwani district of Haryana (India) through LANDSAT-7ETM+ and remote sensing techniques

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    This study describes the VIs Vegetation Condition Index in term of vegetation health of wheat crop; with help of LANDSAT-7ETM+ data based NDVI and LAI for Bhiwani District of Haryana states (India) and gave the spatial development pattern of wheat crop in year 2005 over the study area of India. NDVI is found to vary from 0.3 to 0.8. In northern and southern parts of study area NDVI varied from 0.6 to 0.7 but in western part of Bhiwani showed NDVI 0.2 to 0.4 due to fertility of soil and well canal destitution. LAI showed variation from 1 to 6 accordingto the health of crop as the same manner of NDVI because LAI VI is NDVI dependent only change the manner of representation of vegetation health, due to this fact relation curve (r2=) between NDVI and LAI of four different growing date of sates are in successively increasing order 0.509, 0.563, 0.577 and 0.719. The study reveals that VIs can be mapped with LANDSAT-7ETM+ through remote sensing, which can be further used for many studies like crop yield or estimating evaptranspiration on regional basis for water management because satellite observations provide better spatial and temporal coverage, the VIs based system will provide efficient tools for monitoring health of crop for improvement of agricultural planning. VIs based monitoring will serve as a prototype in the other parts of the world where ground observations are limited or not available

    Hakha Lai Definites

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    This paper uses fieldwork data to investigate definite expressions in Hakha Lai, a Kuki-Chin language spoken in western Burma/Myanmar and southern Indianapolis. Previous investigations of definite expressions (Hawkins 1978, Heim 1982, Roberts 2003, Schwarz 2009, and others) have posited properties such as uniqueness and identifiability as well as anaphoric reference as key features of definiteness. In an analysis of German definite articles, Schwarz (2009) proposes that definite expressions can be divided into two categories, weak definites, correlated with the semantic uniqueness of a referent, and strong definites which are correlated with anaphoric reference. Hakha Lai has two postnominal adjuncts, kha and cu, whose behavior is consistent with Schwarz’s weak and strong definites. This data from Hakha Lai expands upon previous research on definite expressions cross-linguistically and investigates the relationship between definiteness and its morphosemantic representations in natural language

    Application of the EM-algorithm for Bayesian network modelling to improve forest growth estimates

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    AbstractLeaf area index (LAI) is a biophysical variable that is related to atmosphere-biosphere exchange of CO2. One way to obtain LAI value is by the Moderate Resolution Imaging Spectroradiometer (MODIS) biophysical products (LAI MODIS). The LAI MODIS has been used to improve the physiological principles predicting growth (3-PG) model within a Bayesian Network (BN) set-up. The MODIS time series, however, contains gaps caused by persistent clouds, cloud contamination, and other retrieval problems. We therefore formulated the EM-algorithm to estimate the missing MODIS LAI values. The EM-algorithm is applied to three different cases: successive and not successive two winter seasons, and not successive missing MODIS LAI during the time study of 26 successive months at which the performance of the BN is assessed. Results show that the MODIS LAI is estimated such that the maximum value of the mean absolute error between the original MODIS LAI and the estimated MODIS LAI by EM-algorithm is 0.16. This is a low value, and shows the success of our approach. Moreover, the BN output improves when the EM-algorithm is carried out to estimate the inconsecutive missing MODIS LAI such that the root mean square error reduces from 1.57 to 1.49. We conclude that the EM-algorithm within a BN can handle the missing MODIS LAI values and that it improves estimation of the LAI

    Microstructural evolution in materials during thermal processing

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    Copyright © 2012 Joseph K. L. Lai et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.This article is made available through the Brunel Open Access Publishing Fund

    The relationship between tax evasion and tax revenue in Chang, Lai and Chang (1999)

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    Chang, Lai and Chang (1999) use a micro-founded short-term macroeconomic model, with an imperfectly competitive market, to analyze, among other issues, the relationship between tax evasion and tax revenue. They show that this relationship depends upon the market structure. In particular, when the market becomes perfectly competitive, this relationship can be non monotonic. Although CLC give an intuition of this result, based on the interaction of two opposite effects, they do not make explicit the form of this relationship. The goal of this note is precisely to show that, within the Chang, Lai and Chang (1999) model, one can completely characterize the shape of the relationship between tax evasion and tax revenue under perfect competition. Under some parametric conditions, the tax revenue decreases with tax evasion otherwise, their relationship takes the form of a `Laffer curve'.
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