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Moving Window (moving + window)
Terms modified by Moving Window Selected AbstractsQuality, Trade and the Moving Window: The Globalisation Process,THE ECONOMIC JOURNAL, Issue 524 2007John Sutton The globalisation process is analysed in a model where firms differ in productivity and quality. A lower bound to quality emerges, below which firms cannot sell, however low their (local) wage rate. The range of quality levels between the maximum and this lower bound shifts upwards when trade is liberalised (the ,moving window'). The initial phase of globalisation, associated with trade liberalisation, in an initially segmented (but not autarkic) world, may reduce welfare in countries with intermediate levels of capability, but these countries may be the most important gainers as capabilities are transferred in subsequent phases. [source] Association of ecotones with relative elevation and fire in an upland Florida landscapeJOURNAL OF VEGETATION SCIENCE, Issue 3 2006E.A. Boughton Abstract: Question: What are the importance of elevation and fire in maintaining ecotones of Florida scrub assemblages along a gradual topographic gradient? Location: Archbold Biological Station (ABS), 12 km south of Lake Placid, Florida, USA. Methods: Vegetation cover of upland Florida shrublands was quantified using the line-intercept method along 20 transects traversing similar elevation gradients, stratified by time since fire (TSF). We objectively identified shrubland ecotones using a split moving windows boundary analysis (SMW) with three different window widths. Non-metric multidimensional scaling ordination was used to determine relationships among plant assemblages defined by SMW. Results: We located up to four ecotones per transect, the majority of which were wide, highly heterogeneous zones. Relative elevation controlled the distribution of plant assemblages in upland Florida shrublands. Ecotones in shrublands > 30 years TSF had relatively low dissimilarity values in SMW, indicating that previously discrete plant assemblages with longer TSF were becoming more similar with time. Conclusions Split Moving Windows (SMW) analysis identified ecotones relatively well although patches generated by oak clonal growth were sometimes identified as ecotones. Fire suppression caused ecotones to become more diffuse, suggesting that without fire at least every 30 years, discrete plant assemblages within upland Florida shrublands will be more continuous. [source] Moving window as a variable selection method in potentiometric titration multivariate calibration and its application to the simultaneous determination of ions in Raschig synthesis mixturesJOURNAL OF CHEMOMETRICS, Issue 3 2009Sheng Fang Abstract A novel method based on moving window (MW) strategy has been proposed to simultaneously choose the optimal pH region and latent variables (LVs) number for partial least squares (PLS) regression in potentiometric titration multivariate calibration. In this method, the leave-one-out cross-validation with varying LVs number is run on different selected MW and, consequently, that revealing optimal results is selected. The method is applied to the simultaneous determination of H+, NH3OH+ and NH in Raschig synthesis mixtures, which is of industrial importance. A comparison in the modeling power of PLS is made between non-processed data set and data set processed by the MW method. Copyright © 2008 John Wiley & Sons, Ltd. [source] Urban Textural Analysis from Remote Sensor Data: Lacunarity Measurements Based on the Differential Box Counting MethodGEOGRAPHICAL ANALYSIS, Issue 4 2006Soe W. Myint Lacunarity is related to the spatial distribution of gap or hole sizes. For low lacunarity, all gap sizes are the same and geometric objects are deemed homogeneous; conversely, for high lacunarity, gap sizes are variable and objects are therefore heterogeneous. Textures that are homogeneous at small scales can be quite heterogeneous at large scales and vice versa, and hence, lacunarity can be considered a scale-dependent measure of heterogeneity or texture. In this article, we use a lacunarity method based on a differential box counting approach to identify urban land-use and land-cover classes from satellite sensor data. Our methodology focuses on two different gliding box methods to compute lacunarity values and demonstrate a mirror extension approach for a local moving window. The extension approach overcomes, or at least minimizes, the boundary problem. The results from our study suggest that the overlapping box approach is more effective than the skipping box approach, but that there is no significant difference between window sizes. Our work represents a contribution to not only advances in textural and spatial metrics as used in remote-sensing pattern interpretation but also for broadening understanding of the computational geometry of nonlinear shape models of which lacunarity is the reciprocal of fractal theory. [source] 3D float tracking: in situ floodplain roughness estimationHYDROLOGICAL PROCESSES, Issue 2 2009Menno Straatsma Abstract This paper presents a novel technique to quantify in situ hydrodynamic roughness of submerged floodplain vegetation: 3D float tracking. This method uses a custom-built floating tripod that is released on the inundated floodplain and tracked from shore by a robotic total station. Simultaneously, an acoustic Doppler current profiler (ADCP) collects flow velocity profiles and water depth data. Roughness values are derived from two methods based on (1) run-averaged values of water depth, slope and flow velocity to compute the roughness based on the Chézy equation, assuming uniform flow, (2) the equation for one-dimensional free surface flow in a moving window. A sensitivity analysis using synthetic data proved that the median value of the roughness, derived using method 2, is independent of (1) the noise in water levels, up to 9 mm, (2) bottom surface slope, and (3) topographic undulations. The window size should be at least 40 m for a typical lowland river setup. Field measurements were carried out on two floodplain sections with an average vegetation height of 0·030 (Arnhem) and 0·043 m (Dreumel). Method 1 resulted in a Nikuradse roughness length of 0·08 m for both locations. Method 2 gave 0·12 m for Arnhem and 0·19 m for Dreumel. In Arnhem, a spatial pattern of roughness values was present, which might be related to fractional vegetation cover or vegetation density during the flood peak. 3D float tracking proved a flexible and detailed method for roughness determination in the absence of waves, and provided an unrestricted view from shore. Copyright © 2008 John Wiley & Sons, Ltd. [source] A regional frequency analysis of United Kingdom extreme rainfall from 1961 to 2000INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 11 2003H. J. Fowler Abstract Multi-day rainfall events are an important cause of recent severe flooding in the UK, and any change in the magnitude of such events may have severe impacts upon urban structures such as dams, urban drainage systems and flood defences and cause failures to occur. Regional pooling of 1-, 2-, 5- and 10-day annual maxima for 1961 to 2000 from 204 sites across the UK is used in a standard regional frequency analysis to produce generalized extreme value growth curves for long return-period rainfall events for each of nine defined climatological regions. Temporal changes in 1-, 2-, 5- and 10-day annual maxima are examined with L-moments using both a 10 year moving window and the fixed decades of 1961,70, 1971,80, 1981,90 and 1991,2000. A bootstrap technique is then used to assess uncertainty in the fitted decadal growth curves and to identify significant trends in both distribution parameters and quantile estimates. There has been a two-part change in extreme rainfall event occurrence across the UK from 1961 to 2000. Little change is observed at 1 and 2 days duration, but significant decadal-level changes are seen in 5- and 10-day events in many regions. In the south of the UK, growth curves have flattened and 5- and 10-day annual maxima have decreased during the 1990s. However, in the north, the 10-day growth curve has steepened and annual maxima have risen during the 1990s. This is particularly evident in Scotland. The 50 year event in Scotland during 1961,90 has become an 8-year, 11-year and 25-year event in the East, South and North Scotland pooling regions respectively during the 1990s. In northern England the average recurrence interval has also halved. This may have severe implications for design and planning practices in flood control. Copyright © 2003 Royal Meteorological Society [source] Moving window as a variable selection method in potentiometric titration multivariate calibration and its application to the simultaneous determination of ions in Raschig synthesis mixturesJOURNAL OF CHEMOMETRICS, Issue 3 2009Sheng Fang Abstract A novel method based on moving window (MW) strategy has been proposed to simultaneously choose the optimal pH region and latent variables (LVs) number for partial least squares (PLS) regression in potentiometric titration multivariate calibration. In this method, the leave-one-out cross-validation with varying LVs number is run on different selected MW and, consequently, that revealing optimal results is selected. The method is applied to the simultaneous determination of H+, NH3OH+ and NH in Raschig synthesis mixtures, which is of industrial importance. A comparison in the modeling power of PLS is made between non-processed data set and data set processed by the MW method. Copyright © 2008 John Wiley & Sons, Ltd. [source] Quality, Trade and the Moving Window: The Globalisation Process,THE ECONOMIC JOURNAL, Issue 524 2007John Sutton The globalisation process is analysed in a model where firms differ in productivity and quality. A lower bound to quality emerges, below which firms cannot sell, however low their (local) wage rate. The range of quality levels between the maximum and this lower bound shifts upwards when trade is liberalised (the ,moving window'). The initial phase of globalisation, associated with trade liberalisation, in an initially segmented (but not autarkic) world, may reduce welfare in countries with intermediate levels of capability, but these countries may be the most important gainers as capabilities are transferred in subsequent phases. [source] Climate variability and change in the Greater Alpine Region over the last two centuries based on multi-variable analysisINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 15 2009Michele Brunetti Abstract An extensive analysis of the HISTALP database is presented with the aim of giving a comprehensive picture of secular climate variability and change in the Greater Alpine Region (GAR, 4,19 E, 43,49 N). The HISTALP database encompasses 242 sites and concerns temperature, pressure, precipitation, cloudiness, sunshine duration, vapour pressure and relative humidity. The analyses are based on four regional mean records representing different GAR low-level areas and on an additional mean record representing high-level locations. The first goal of the paper is to give an overview of the seasonal and annual records for the different variables, aiming to highlight both variability on decadal time scale and long-term evolution. Then it focuses on trend and correlation analysis. Trends are presented both for the period of common data availability for all regional average series and for moving windows that permit studying the trends over a wide range of timescales. Correlations among the different variables are presented both for the regional average series and for their high-pass-filtered versions. The analyses, beside highlighting a warming that is about twice as large as the global trend, also show that the different variables have responded in different ways to this warming and that the mutual interactions linking the different variables are often present only at specific temporal scales and only in parts of the GAR and in defined seasons. In spite of this complex behaviour, which may also be due to some residual inhomogeneities still affecting the data, the analyses give evidence that the HISTALP database has an excellent internal consistency and show that the availability of a multi-variable database turns out to be very useful in order to evaluate the reliability of the reconstruction of each variable and to better understand the behaviour and the mutual interactions of the different variables. Copyright © 2009 Royal Meteorological Society [source] | ||||||||||