Spatial photon correlations in multiple scattering media

DEFF Research Database (Denmark)

Smolka, Stephan; Muskens, O.; Lagendijk, A.

2010-01-01

We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations.......We present the first angle-resolved measurements of spatial photon correlations that are induced by multiple scattering of light. The correlation relates multiple scattered photons at different spatial positions and depends on incident photon fluctuations....

Velocity correlations and spatial dependencies between neighbors in a unidirectional flow of pedestrians

Science.gov (United States)

Porzycki, Jakub; WÄ s, Jarosław; Hedayatifar, Leila; Hassanibesheli, Forough; Kułakowski, Krzysztof

2017-08-01

The aim of the paper is an analysis of self-organization patterns observed in the unidirectional flow of pedestrians. On the basis of experimental data from Zhang et al. [J. Zhang et al., J. Stat. Mech. (2011) P06004, 10.1088/1742-5468/2011/06/P06004], we analyze the mutual positions and velocity correlations between pedestrians when walking along a corridor. The angular and spatial dependencies of the mutual positions reveal a spatial structure that remains stable during the crowd motion. This structure differs depending on the value of n , for the consecutive n th -nearest-neighbor position set. The preferred position for the first-nearest neighbor is on the side of the pedestrian, while for further neighbors, this preference shifts to the axis of movement. The velocity correlations vary with the angle formed by the pair of neighboring pedestrians and the direction of motion and with the time delay between pedestrians' movements. The delay dependence of the correlations shows characteristic oscillations, produced by the velocity oscillations when striding; however, a filtering of the main frequency of individual striding out reduces the oscillations only partially. We conclude that pedestrians select their path directions so as to evade the necessity of continuously adjusting their speed to their neighbors'. They try to keep a given distance, but follow the person in front of them, as well as accepting and observing pedestrians on their sides. Additionally, we show an empirical example that illustrates the shape of a pedestrian's personal space during movement.

Cell Matrix Remodeling Ability Shown by Image Spatial Correlation

Science.gov (United States)

Chiu, Chi-Li; Digman, Michelle A.; Gratton, Enrico

2013-01-01

Extracellular matrix (ECM) remodeling is a critical step of many biological and pathological processes. However, most of the studies to date lack a quantitative method to measure ECM remodeling at a scale comparable to cell size. Here, we applied image spatial correlation to collagen second harmonic generation (SHG) images to quantitatively evaluate the degree of collagen remodeling by cells. We propose a simple statistical method based on spatial correlation functions to determine the size of high collagen density area around cells. We applied our method to measure collagen remodeling by two breast cancer cell lines (MDA-MB-231 and MCF-7), which display different degrees of invasiveness, and a fibroblast cell line (NIH/3T3). We found distinct collagen compaction levels of these three cell lines by applying the spatial correlation method, indicating different collagen remodeling ability. Furthermore, we quantitatively measured the effect of Latrunculin B and Marimastat on MDA-MB-231 cell line collagen remodeling ability and showed that significant collagen compaction level decreases with these treatments. PMID:23935614

Temporal and spatial variations of patches, corridors and matrix in humid soil (mallín in the mid-west of the province of Neuquén

Directory of Open Access Journals (Sweden)

Ricardo Gandullo

2006-01-01

Full Text Available Natural processes, like human activities, change the landscape. This reality is somehow related to humid soils (mallines in Patagonia. The mallines are important natural ecosystems that provide forage to extensive animal husbandry. They represent 4 of the Patagonic surface. The wet and dry periods modify the hydrologic dynamics of the mallín, producing an effect on the evolution of patches, corridors and matrix, which worsens with the anthropic activity. In a temporal sequence, the habitat fragmentation can be observed, i.e. in the variation and size of the number of patches, their shape, connectivity and isolation, which together with other factors affect the numerous ecological processes. Knowledge of the temporal and spatial dynamics of the patches, corridors and matrix between wet and dry periods in humid soils allows for the planning of the use of the vegetation resources, since the spatial standards strongly control their movements, flows and changes.

Accounting for connectivity and spatial correlation in the optimal placement of wildlife habitat

Science.gov (United States)

John Hof; Curtis H. Flather

1996-01-01

This paper investigates optimization approaches to simultaneously modelling habitat fragmentation and spatial correlation between patch populations. The problem is formulated with habitat connectivity affecting population means and variances, with spatial correlations accounted for in covariance calculations. Population with a pre-specifled confidence level is then...

Potential corridors and barriers for plague spread in central Asia

Science.gov (United States)

2013-01-01

Background Plague (Yersinia pestis infection) is a vector-borne disease which caused millions of human deaths in the Middle Ages. The hosts of plague are mostly rodents, and the disease is spread by the fleas that feed on them. Currently, the disease still circulates amongst sylvatic rodent populations all over the world, including great gerbil (Rhombomys opimus) populations in Central Asia. Great gerbils are social desert rodents that live in family groups in burrows, which are visible on satellite images. In great gerbil populations an abundance threshold exists, above which plague can spread causing epizootics. The spatial distribution of the host species is thought to influence the plague dynamics, such as the direction of plague spread, however no detailed analysis exists on the possible functional or structural corridors and barriers that are present in this population and landscape. This study aims to fill that gap. Methods Three 20 by 20 km areas with known great gerbil burrow distributions were used to analyse the spatial distribution of the burrows. Object-based image analysis was used to map the landscape at several scales, and was linked to the burrow maps. A novel object-based method was developed – the mean neighbour absolute burrow density difference (MNABDD) – to identify the optimal scale and evaluate the efficacy of using landscape objects as opposed to square cells. Multiple regression using raster maps was used to identify the landscape-ecological variables that explain burrow density best. Functional corridors and barriers were mapped using burrow density thresholds. Cumulative resistance of the burrow distribution to potential disease spread was evaluated using cost distance analysis. A 46-year plague surveillance dataset was used to evaluate whether plague spread was radially symmetric. Results The burrow distribution was found to be non-random and negatively correlated with Greenness, especially in the floodplain areas. Corridors and

The Relationship Between Spatial Configuration and Social Interaction in High-Rise Flats: A Case Study On The Jatinegara Barat in Jakarta.

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Ridwana Rifan

2018-01-01

The results of this study indicate that: (1 the relationship of spatial configuration to social interaction level in Jatinegara Barat flats can be positive or negative. (2 Positive relationships are found on the1st and 2ndfloor areas. High configuration values with high interaction levels are found in shared spaces on the 1st and 2nd floors with characteristics such as open space, large space, and availability of interaction supporting elements, while low configuration values with low interaction levels are found in more confined spaces such as private spaces and narrow corridors. (3 Negative relationships are found in the corridor and shared space in front of the elevator on each typical floors. Shared space in front of the elevator that has high spatial configuration value with large area show a low level of social interaction. While corridor with lower configuration value with the narrow area but have supporting elements such as chairs, mats, and shops have a higher level of social interaction. (4 This study shows that in the case of the relationship between spatial configuration and social interaction, availability of interaction supporting elements has greater influence rather than any other spatial factors.

KPI Building Blocks For Successful Green Transport Corridor Implementation

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Prause Gunnar

2015-12-01

Full Text Available The green transport corridor concept represents a cornerstone in the development of integrated and sustainable transport solutions. Important properties of green corridors are their transnational character and their high involvement of large numbers of public and private stakeholders, including political level, requiring sophisticated approaches for implementation, management and governance. The current scientific discussion focusses on Key Performance Indicators (KPI for monitoring and management of green transport corridor performance emphasizing the operational aspects.

Indirect Validation of Probe Speed Data on Arterial Corridors

Energy Technology Data Exchange (ETDEWEB)

Eshragh, Sepideh [Center for Advanced Transportation Technology, University of Maryland, College Park, 5000 College Avenue, Suite 2206, College Park, MD 20742; Young, Stanley E. [National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401; Sharifi, Elham [Center for Advanced Transportation Technology, University of Maryland, College Park, 5000 College Avenue, Suite 2206, College Park, MD 20742; Hamedi, Masoud [Center for Advanced Transportation Technology, University of Maryland, College Park, 5000 College Avenue, Suite 2206, College Park, MD 20742; Sadabadi, Kaveh Farokhi [Center for Advanced Transportation Technology, University of Maryland, College Park, 5000 College Avenue, Suite 2206, College Park, MD 20742

2017-01-01

This study aimed to estimate the accuracy of probe speed data on arterial corridors on the basis of roadway geometric attributes and functional classification. It was assumed that functional class (medium and low) along with other road characteristics (such as weighted average of the annual average daily traffic, average signal density, average access point density, and average speed) were available as correlation factors to estimate the accuracy of probe traffic data. This study tested these factors as predictors of the fidelity of probe traffic data by using the results of an extensive validation exercise. This study showed strong correlations between these geometric attributes and the accuracy of probe data when they were assessed by using average absolute speed error. Linear models were regressed to existing data to estimate appropriate models for medium- and low-type arterial corridors. The proposed models for medium- and low-type arterials were validated further on the basis of the results of a slowdown analysis. These models can be used to predict the accuracy of probe data indirectly in medium and low types of arterial corridors.

Response of Wolves to Corridor Restoration and Human Use Management

Directory of Open Access Journals (Sweden)

Brenda Shepherd

2006-12-01

Full Text Available Corridor restoration is increasingly being used to connect habitat in mountainous areas where rugged topography and increasing human activity fragment habitat. Wolves (Canis lupus are a conservation priority because they avoid areas with high levels of human use and are ecologically important predators. We examined how corridor restoration through a golf course changes the distribution of wolves and their prey in Jasper National Park, Alberta, Canada. We followed and recorded wolf paths in the snow both within the corridor and in the surrounding landscape before and after a corridor was re-established. Track transects were used to estimate prey abundance and snow depths, and trail counters measured human activity. We compared resources on wolf paths to available movement routes using conditional logistic regression and also compared resources used by wolves before and after restoration. We addressed potential confounding effects of prey abundance, snow depths, and levels of human use by testing for changes in these variables. Prior to restoration, wolves traveled around the golf course and used the mountainside to connect valley-bottom habitat. Conversely, elk (Cervus elaphus densities were highest in the golf course. After restoration, wolves shifted most of their movement to the golf course corridor, whereas elk dispersed along the corridor and mountainside. When traveling through the study area, wolves selected for areas with high prey abundance, low elevations, and low levels of human activity. Corridor restoration increased the area of high quality habitat available to wolves and increased their access to elk and deer at low elevations. Our results corroborate other studies suggesting that wolves and elk quickly adapt to landscape changes and that corridor restoration can improve habitat quality and reduce habitat fragmentation.

WHEN THE DISTURBANCES ARE SPATIALLY CORRELATED

African Journals Online (AJOL)

correlation, spatial error process. INTRODUCTION. Consider the linear regression model for spatial correlation y=XB +u, u=Ce, (1) where y is a Txl observable random vector, X is a Txk matrix of known constants with full column rank k, B is a k xl vector of unknown parameters,. :2 is a Txl random vector with expectation zero ...

Factors affecting buccal corridor space in Angle′s Class II Division 1 malocclusion

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Rashmi Bhat

2014-01-01

Full Text Available Background and Objectives: Buccal corridor space has been thought of primarily in terms of maxillary width, but there is also evidence that they are heavily influenced by the antero-posterior position of maxilla. The present study was undertaken with an aim of evaluating and comparing the dental and skeletal factors related to buccal corridor space in individuals having Class I and Class II Division 1 malocclusions. Materials and Methods: A total of 80 subjects of which 40 were males and 40 were females in the age group of 20-30 years were selected as per inclusion criteria and were grouped as Group I having Class I malocclusion and as Group II having Class II malocclusions based on angle ANB. 12 linear and 2 angular cephalometric measurements and 4 study cast measurements were used to correlate with the buccal corridor linear ratio (BCLR, calculated on smile photograph using the Adobe Photoshop 7.0 software (Adobe Systems Inc., San Jose, California, USA. The data obtained was statistically evaluated using independent t-test and multiple linear regression analysis. Result: Buccal corridor space is larger in individuals with Class II Division 1 malocclusion when compared with individuals with Class I malocclusions. There exists a significant difference in buccal corridor space between males and females. Conclusion: The present study helps in establishing the correlation between certain factors and the amount of buccal corridor space in individuals having skeletal Class II pattern.

A model relating Eulerian spatial and temporal velocity correlations

Science.gov (United States)

Cholemari, Murali R.; Arakeri, Jaywant H.

2006-03-01

In this paper we propose a model to relate Eulerian spatial and temporal velocity autocorrelations in homogeneous, isotropic and stationary turbulence. We model the decorrelation as the eddies of various scales becoming decorrelated. This enables us to connect the spatial and temporal separations required for a certain decorrelation through the ‘eddy scale’. Given either the spatial or the temporal velocity correlation, we obtain the ‘eddy scale’ and the rate at which the decorrelation proceeds. This leads to a spatial separation from the temporal correlation and a temporal separation from the spatial correlation, at any given value of the correlation relating the two correlations. We test the model using experimental data from a stationary axisymmetric turbulent flow with homogeneity along the axis.

Maxillary arch width and buccal corridor changes with Damon and conventional brackets: A retrospective analysis.

Science.gov (United States)

Shook, Corey; Kim, Sohyon Michelle; Burnheimer, John

2016-07-01

To evaluate the effect of Damon self-ligating and conventional bracket systems on buccal corridor widths and areas. A retrospective sample of consecutively treated patients using either conventional (CG, n  =  45) or Damon self-ligating (SL, n  =  39) brackets was analyzed to determine any differences in buccal corridor widths and areas both within and between groups. Pretreatment and posttreatment frontal photographs were transferred to Photoshop CC, standardized using intercanthal width, and linear and area measurements were performed with tools in Photoshop CC. Ratios were then calculated for statistical analysis. Relationships between arch widths and buccal corridors were also examined. There were no significant differences in the posttreatment intercanine or intermolar widths either within or between the CG and SL groups. There were no significant differences in any buccal corridor width or area measurement either within or between the CG and SL groups. There were strong correlations with the intercanine width and the corresponding buccal corridor smile width measurements. There was an inverse correlation with the buccal corridor area in relation to the canine and the total smile width. It is likely that posttreatment increases in arch width can be seen in patients treated with either a conventional bracket system or the Damon system. It is highly unlikely that there is any significant difference in buccal corridor width or area in patients treated with the Damon self-ligating system or a conventional bracket system.

Model-based corridor performance analysis – An application to a European case

DEFF Research Database (Denmark)

Panagakos, George; Psaraftis, Harilaos N.

2017-01-01

to a number of Key Performance Indicators (KPIs). It consists of decomposing the corridor into transport chains, selecting a sample of typical chains, assessing these chains through a set of KPIs, and then aggregating the chain-level KPIs to corridor-level ones using proper weights. A critical feature...... refinement and verification. The sample construction part of the methodology was tested on GreCOR, a green corridor project in the North Sea Region, using the Danish National Traffic Model as the principal source of information for both sample construction and KPI estimation. The results show that...

Generating Improved Experimental Designs with Spatially and Genetically Correlated Observations Using Mixed Models

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Lazarus K. Mramba

2018-03-01

Full Text Available The aim of this study was to generate and evaluate the efficiency of improved field experiments while simultaneously accounting for spatial correlations and different levels of genetic relatedness using a mixed models framework for orthogonal and non-orthogonal designs. Optimality criteria and a search algorithm were implemented to generate randomized complete block (RCB, incomplete block (IB, augmented block (AB and unequally replicated (UR designs. Several conditions were evaluated including size of the experiment, levels of heritability, and optimality criteria. For RCB designs with half-sib or full-sib families, the optimization procedure yielded important improvements under the presence of mild to strong spatial correlation levels and relatively low heritability values. Also, for these designs, improvements in terms of overall design efficiency (ODE% reached values of up to 8.7%, but these gains varied depending on the evaluated conditions. In general, for all evaluated designs, higher ODE% values were achieved from genetically unrelated individuals compared to experiments with half-sib and full-sib families. As expected, accuracy of prediction of genetic values improved as levels of heritability and spatial correlations increased. This study has demonstrated that important improvements in design efficiency and prediction accuracies can be achieved by optimizing how the levels of a treatment are assigned to the experimental units.

Spatial correlation of probabilistic earthquake ground motion and loss

Science.gov (United States)

Wesson, R.L.; Perkins, D.M.

2001-01-01

Spatial correlation of annual earthquake ground motions and losses can be used to estimate the variance of annual losses to a portfolio of properties exposed to earthquakes A direct method is described for the calculations of the spatial correlation of earthquake ground motions and losses. Calculations for the direct method can be carried out using either numerical quadrature or a discrete, matrix-based approach. Numerical results for this method are compared with those calculated from a simple Monte Carlo simulation. Spatial correlation of ground motion and loss is induced by the systematic attenuation of ground motion with distance from the source, by common site conditions, and by the finite length of fault ruptures. Spatial correlation is also strongly dependent on the partitioning of the variability, given an event, into interevent and intraevent components. Intraevent variability reduces the spatial correlation of losses. Interevent variability increases spatial correlation of losses. The higher the spatial correlation, the larger the variance in losses to a port-folio, and the more likely extreme values become. This result underscores the importance of accurately determining the relative magnitudes of intraevent and interevent variability in ground-motion studies, because of the strong impact in estimating earthquake losses to a portfolio. The direct method offers an alternative to simulation for calculating the variance of losses to a portfolio, which may reduce the amount of calculation required.

Spatial correlations, clustering and percolation-like transitions in homicide crimes

Science.gov (United States)

Alves, L. G. A.; Lenzi, E. K.; Mendes, R. S.; Ribeiro, H. V.

2015-07-01

The spatial dynamics of criminal activities has been recently studied through statistical physics methods; however, models and results have been focusing on local scales (city level) and much less is known about these patterns at larger scales, e.g. at a country level. Here we report on a characterization of the spatial dynamics of the homicide crimes along the Brazilian territory using data from all cities (˜5000) in a period of more than thirty years. Our results show that the spatial correlation function in the per capita homicides decays exponentially with the distance between cities and that the characteristic correlation length displays an acute increasing trend in the latest years. We also investigate the formation of spatial clusters of cities via a percolation-like analysis, where clustering of cities and a phase-transition-like behavior describing the size of the largest cluster as a function of a homicide threshold are observed. This transition-like behavior presents evolutive features characterized by an increasing in the homicide threshold (where the transitions occur) and by a decreasing in the transition magnitudes (length of the jumps in the cluster size). We believe that our work sheds new light on the spatial patterns of criminal activities at large scales, which may contribute for better political decisions and resources allocation as well as opens new possibilities for modeling criminal activities by setting up fundamental empirical patterns at large scales.

Localization in a one-dimensional spatially correlated random potential

International Nuclear Information System (INIS)

Kasner, M.; Weller, W.

1986-01-01

The motion of an electron in a random one-dimensional spatially correlated potential is investigated. The spatial correlation is generated by a Markov chain. It is shown that the influence of the spatial correlation can be described by means of oscillating vertices usually neglected in the Berezinskii diagram technique. Correlation mainly leads to an increase of the localization length in comparison with an uncorrelated potential. However, there is a region of the parameter, where the localization decreases. (author)

[Identification of ecological corridors for Tibetan antelope and assessment of their human disturbances in the alpine desert of Qinghai-Tibet Plateau].

Science.gov (United States)

Zhuge, Hai-jin; Lin, Dan-qi; Li, Xiao-wen

2015-08-01

The alpine desert of Qinghai-Tibet Plateau (QTP) provides the largest habitats for those endangered ungulates (e.g., Tibetan antelope, Tibetan Kiang and wild yak) on the earth. However, human disturbance especially infrastructure constructions (e.g., railway & highway) has increasingly fragmented the habitats of those endangered ungulates by disturbing and interrupting their ecological corridors for their seasonal migration. Aiming at identifying the potential ecological corridors for Tibetan antelope, a GIS-based model-Linkage Mapper was used to model and detect the potential ecological corridors of Tibetan antelope based on the principle of least cost path. Three categories of ecological corridors, i. e., closed (inside reserves), linking (linking the reserves) and open (starting from reserve but ending outside) corridors were distinguished by their spatial interactions with existing major national nature reserves (i.e., Altun, Kekexili and Qiangtang NNRs) in the alpine desert of QTP, and their spatial patterns, conservation status associated with human disturbance were also examined. Although our research indicated a general ecological integration of both habitats and ecological corridors in the alpine desert ecosystem, increasing human disturbance should not be ignored, which particularly partially undermined the functioning of those ecological corridors linking the nature reserves. Considering disadvantages of prevailing separate administrative structure of nature reserve on the effective conservation of ecological corridors for those endangered ungulates, a coordinative conservation network among these major national nature reserves should be established to ensure the unified trans-boundary conservation efforts and to enhance its overall conservation efficacy by sharing information, knowledge and optimizing conservation resources.

From corridor to region

DEFF Research Database (Denmark)

Jensen, Anne; Jespersen, Per Homann

2006-01-01

The corridor between Oslo and Berlin is by the politicians of the regional authorities in the Scandinavian part of the corridor seen a region with unique qualities and a large innovation and growth potential. In order to explore and develop this potential an In-terreg project has been launched...... this task by applying principles of participative planning and with action research methodology are involving stakeholders in the process of defining, developing and disseminating the idea of the Corridor of Innovation and Cooperation - COINCO....

Spatial Correlation Of Streamflows: An Analytical Approach

Science.gov (United States)

Betterle, A.; Schirmer, M.; Botter, G.

2016-12-01

The interwoven space and time variability of climate and landscape properties results in complex and non-linear hydrological response of streamflow dynamics. Understanding how meteorologic and morphological characteristics of catchments affect similarity/dissimilarity of streamflow timeseries at their outlets represents a scientific challenge with application in water resources management, ecological studies and regionalization approaches aimed to predict streamflows in ungauged areas. In this study, we establish an analytical approach to estimate the spatial correlation of daily streamflows in two arbitrary locations within a given hydrologic district or river basin at seasonal and annual time scales. The method is based on a stochastic description of the coupled streamflow dynamics at the outlet of two catchments. The framework aims to express the correlation of daily streamflows at two locations along a river network as a function of a limited number of physical parameters characterizing the main underlying hydrological drivers, that include climate conditions, precipitation regime and catchment drainage rates. The proposed method portrays how heterogeneity of climate and landscape features affect the spatial variability of flow regimes along river systems. In particular, we show that frequency and intensity of synchronous effective rainfall events in the relevant contributing catchments are the main driver of the spatial correlation of daily discharge, whereas only pronounced differences in the drainage rate of the two basins bear a significant effect on the streamflow correlation. The topological arrangement of the two outlets also influences the underlying streamflow correlation, as we show that nested catchments tend to maximize the spatial correlation of flow regimes. The application of the method to a set of catchments in the South-Eastern US suggests the potential of the proposed tool for the characterization of spatial connections of flow regimes in the

Transportation of Dangerous Goods in Green Transport Corridors - Conclusions from Baltic Sea Region

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Schröder Meike

2016-12-01

Full Text Available The Green Corridor concept represents a cornerstone in the development and implementation of integrated and sustainable transport solutions based on trans-nationality, multi-modality and a high involvement of public and private stakeholders, including the political level. Despite the fact that the Green Transport Corridor (GTC concept is founded on the three dimensions of sustainability with a strong emphasis on environmental aspects, the corridor hubs as well as the whole transport corridors have to find ways to handle and transport dangerous goods by keeping the high sustainability standards.

Climate change and sea ice: Shipping accessibility on the marine transportation corridor through Hudson Bay and Hudson Strait (1980–2014

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Jonathan Andrews

2017-03-01

Full Text Available Shipping traffic has been increasing in Hudson Strait and Hudson Bay and the shipping route through these waters to the Port of Churchill may soon become a federally-designated transportation corridor. A dataset on passive microwave-based sea ice concentration was used to characterize the timing of the ice on the shipping corridor to the Port between 1980 and 2014. Efforts were made to produce results in a readily accessible format for stakeholders of the shipping industry; for example, open water was defined using a sea ice concentration threshold of ≤ 15% and results are presented in terms of real dates instead of anomalies. Between 1980 and 2014, the average breakup date on the corridor was July 4, the average freeze-up date was November 25, and the average length of the open water season was 145 days. However, each of these three variables exhibited significant long-term trends and spatial variability over the 34-year time period. Regression analysis revealed significant linear trends towards earlier breakup (–0.66 days year–1, later freeze-up (+0.52 days year–1, and a longer open water season (+1.14 days year–1 along the shipping corridor between 1980 and 2014. Moreover, the section of the corridor passing through Hudson Strait displayed significantly stronger trends than the two sections in Hudson Bay (i.e., “Hudson Islands” and “Hudson Bay”. As a result, sea ice timing in the Hudson Strait section of the corridor has diverged from the timing in the Hudson Bay sections. For example, the 2010–2014 median length of the open water season was 177 days in Hudson Strait and 153 days in the Hudson Bay sections. Finally, significant linear relationships were observed amongst breakup, freeze-up, and the length of the open water season for all sections of the corridor; correlation analysis suggests that these relationships have greatest impact in Hudson Strait.

Fourth-Order Spatial Correlation of Thermal Light

International Nuclear Information System (INIS)

Wen Feng; Zhang Xun; Sun Jia; Song Jian-Ping; Zhang Yan-Peng; Xue Xin-Xin

2014-01-01

We investigate the fourth-order spatial correlation properties of pseudo-thermal light in the photon counting regime, and apply the Klyshko advanced-wave picture to describe the process of four-photon coincidence counting measurement. We deduce the theory of a proof-of-principle four-photon coincidence counting configuration, and find that if the four randomly radiated photons come from the same radiation area and are indistinguishable in principle, the fourth-order correlation of them is 24 times larger than that when four photons come from different radiation areas. In addition, we also show that the higher-order spatial correlation function can be decomposed into multiple lower-order correlation functions, and the contrast and visibility of low-order correlation peaks are less than those of higher orders, while the resolutions all are identical. This study may be useful for better understanding the four-photon interference and multi-channel correlation imaging

Kolmogorov-Smirnov test for spatially correlated data

Science.gov (United States)

Olea, R.A.; Pawlowsky-Glahn, V.

2009-01-01

The Kolmogorov-Smirnov test is a convenient method for investigating whether two underlying univariate probability distributions can be regarded as undistinguishable from each other or whether an underlying probability distribution differs from a hypothesized distribution. Application of the test requires that the sample be unbiased and the outcomes be independent and identically distributed, conditions that are violated in several degrees by spatially continuous attributes, such as topographical elevation. A generalized form of the bootstrap method is used here for the purpose of modeling the distribution of the statistic D of the Kolmogorov-Smirnov test. The innovation is in the resampling, which in the traditional formulation of bootstrap is done by drawing from the empirical sample with replacement presuming independence. The generalization consists of preparing resamplings with the same spatial correlation as the empirical sample. This is accomplished by reading the value of unconditional stochastic realizations at the sampling locations, realizations that are generated by simulated annealing. The new approach was tested by two empirical samples taken from an exhaustive sample closely following a lognormal distribution. One sample was a regular, unbiased sample while the other one was a clustered, preferential sample that had to be preprocessed. Our results show that the p-value for the spatially correlated case is always larger that the p-value of the statistic in the absence of spatial correlation, which is in agreement with the fact that the information content of an uncorrelated sample is larger than the one for a spatially correlated sample of the same size. ?? Springer-Verlag 2008.

VT Electric Transmission Line Corridors - corridor lines

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The ELTRN layer depicts electric transmission line corridors in Vermont. Various methods have been used to digitize features. The data layer...

Spatial correlation in precipitation trends in the Brazilian Amazon

Science.gov (United States)

Buarque, Diogo Costa; Clarke, Robin T.; Mendes, Carlos Andre Bulhoes

2010-06-01

A geostatistical analysis of variables derived from Amazon daily precipitation records (trends in annual precipitation totals, trends in annual maximum precipitation accumulated over 1-5 days, trend in length of dry spell, trend in number of wet days per year) gave results that are consistent with those previously reported. Averaged over the Brazilian Amazon region as a whole, trends in annual maximum precipitations were slightly negative, the trend in the length of dry spell was slightly positive, and the trend in the number of wet days in the year was slightly negative. For trends in annual maximum precipitation accumulated over 1-5 days, spatial correlation between trends was found to extend up to a distance equivalent to at least half a degree of latitude or longitude, with some evidence of anisotropic correlation. Time trends in annual precipitation were found to be spatially correlated up to at least ten degrees of separation, in both W-E and S-N directions. Anisotropic spatial correlation was strongly evident in time trends in length of dry spell with much stronger evidence of spatial correlation in the W-E direction, extending up to at least five degrees of separation, than in the S-N. Because the time trends analyzed are shown to be spatially correlated, it is argued that methods at present widely used to test the statistical significance of climate trends over time lead to erroneous conclusions if spatial correlation is ignored, because records from different sites are assumed to be statistically independent.

Research notes : are safety corridors really safe? Evaluation of the corridor safety improvement program.

Science.gov (United States)

1998-08-26

High accident frequencies on Oregons highway corridors are of concern to the Oregon Department of Transportation (ODOT). : ODOT adopted the Corridor Safety Improvement Program as part of an overall program of safety improvements using federal and ...

A Geophysical Characterization & Monitoring Strategy for Determining Hydrologic Processes in the Hyporheic Corridor at the Hanford 300-Area

Energy Technology Data Exchange (ETDEWEB)

Slater, Lee; Day-Lewis, Frederick; Lane, John; Versteeg, Roelof; Ward, Anderson; Binley, Andrew; Johnson, Timothy; Ntarlagiannis, Dimitrios

2011-08-31

The primary objective of this research was to advance the prediction of solute transport between the Uranium contaminated Hanford aquifer and the Columbia River at the Hanford 300 Area by improving understanding of how fluctuations in river stage, combined with subsurface heterogeneity, impart spatiotemporal complexity to solute exchange along the Columbia River corridor. Our work explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber-optic distributed temperature sensor (FO-DTS) and time-lapse resistivity monitoring, to improve the conceptual model for how groundwater/surface water exchange regulates uranium transport. We also investigated how resistivity and induced polarization can be used to generate spatially rich estimates of the variation in depth to the Hanford-Ringold (H-R) contact between the river and the 300 Area Integrated Field Research Challenge (IFRC) site. Inversion of the CWEI datasets (a data rich survey containing {approx}60,000 measurements) provided predictions of the distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units along the river corridor was reconstructed. Variation in the depth to the interface between the overlying coarse-grained, high permeability Hanford Formation and the underlying finer-grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, has been resolved along {approx}3 km of the river corridor centered on the IFRC site in the Hanford 300 Area. Spatial variability in the thickness of the Hanford Formation captured in the CWEI datasets indicates that previous studies based on borehole projections and drive-point and multi-level sampling likely overestimate the contributing area for uranium exchange within the Columbia River at the Hanford 300 Area. Resistivity and induced polarization imaging between the river and the 300 Area IFRC further imaged spatial

River Corridors (Jan 2, 2015)

Data.gov (United States)

Vermont Center for Geographic Information — River corridors are delineated to provide for the least erosive meandering and floodplain geometry toward which a river will evolve over time. River corridor maps...

The pair correlation function of spatial Hawkes processes

DEFF Research Database (Denmark)

Møller, Jesper; Torrisi, Giovanni Luca

2007-01-01

Spatial Hawkes processes can be considered as spatial versions of classical Hawkes processes. We derive the pair correlation function of stationary spatial Hawkes processes and discuss the connection to the Bartlett spectrum and other summary statistics. Particularly, results for Gaussian fertility...... rates and the extension to spatial Hawkes processes with random fertility rates are discussed....

Comparing the efficiency of transport routes and corridors

Directory of Open Access Journals (Sweden)

Liviu Gabriel GHIŢULEASA

2011-03-01

Full Text Available In the broader context of the importance granted to accessibility by the European spatial planning policies, comparing the efficiency of European and national transportation routes and corridors constitutes an issue of particular relevance for Romania. In order to resolve it, this paper proposes a methodology based on potential accessibility, determined by the total population served, and the efficiency of the path, by analogy with the least squares method. Both approaches were applied to internal and European routes.

Geospatial and machine learning techniques for wicked social science problems: analysis of crash severity on a regional highway corridor

Science.gov (United States)

Effati, Meysam; Thill, Jean-Claude; Shabani, Shahin

2015-04-01

The contention of this paper is that many social science research problems are too "wicked" to be suitably studied using conventional statistical and regression-based methods of data analysis. This paper argues that an integrated geospatial approach based on methods of machine learning is well suited to this purpose. Recognizing the intrinsic wickedness of traffic safety issues, such approach is used to unravel the complexity of traffic crash severity on highway corridors as an example of such problems. The support vector machine (SVM) and coactive neuro-fuzzy inference system (CANFIS) algorithms are tested as inferential engines to predict crash severity and uncover spatial and non-spatial factors that systematically relate to crash severity, while a sensitivity analysis is conducted to determine the relative influence of crash severity factors. Different specifications of the two methods are implemented, trained, and evaluated against crash events recorded over a 4-year period on a regional highway corridor in Northern Iran. Overall, the SVM model outperforms CANFIS by a notable margin. The combined use of spatial analysis and artificial intelligence is effective at identifying leading factors of crash severity, while explicitly accounting for spatial dependence and spatial heterogeneity effects. Thanks to the demonstrated effectiveness of a sensitivity analysis, this approach produces comprehensive results that are consistent with existing traffic safety theories and supports the prioritization of effective safety measures that are geographically targeted and behaviorally sound on regional highway corridors.

Spatial correlation between weed species densities and soil properties

DEFF Research Database (Denmark)

Walter, Mette; Christensen, Svend; Simmelsgaard, Svend Erik

2002-01-01

The spatial cross-correlation between weed species densities and six soil properties within fields was analysed using cross-semivariograms. The survey was carried out in three successive years in two fields. The most consistent relationship between weed species density (numbers m−2) and soil...... properties was negative cross-correlation between the density of Viola arvensis Murray and clay content. This correlation was found in both fields; however, the range of spatial dependence varied between fields. In one of the fields, the density of Lamium purpureum L. was positively cross......-correlated with the phosphorus content in the soil in all years. The density of Veronica spp. and Poa annua L. was negatively cross-correlated with pH in all three years. Other spatial cross-correlations that were found in this study were inconsistent over time or field site. The densities of some of the weed species were...

Quantifying Km-scale Hydrological Exchange Flows under Dynamic Flows and Their Influences on River Corridor Biogeochemistry

Science.gov (United States)

Chen, X.; Song, X.; Shuai, P.; Hammond, G. E.; Ren, H.; Zachara, J. M.

2017-12-01

Hydrologic exchange flows (HEFs) in rivers play vital roles in watershed ecological and biogeochemical functions due to their strong capacity to attenuate contaminants and process significant quantities of carbon and nutrients. While most of existing HEF studies focus on headwater systems with the assumption of steady-state flow, there is lack of understanding of large-scale HEFs in high-order regulated rivers that experience high-frequency stage fluctuations. The large variability of HEFs is a result of interactions between spatial heterogeneity in hydrogeologic properties and temporal variation in river discharge induced by natural or anthropogenic perturbations. Our 9-year spatially distributed dataset (water elevation, specific conductance, and temperature) combined with mechanistic hydrobiogeochemical simulations have revealed complex spatial and temporal dynamics in km-scale HEFs and their significant impacts on contaminant plume mobility and hyporheic biogeochemical processes along the Hanford Reach. Extended multidirectional flow behaviors of unconfined, river corridor groundwater were observed hundreds of meters inland from the river shore resulting from discharge-dependent HEFs. An appropriately sized modeling domain to capture the impact of regional groundwater flow as well as knowledge of subsurface structures controlling intra-aquifer hydrologic connectivity were essential to realistically model transient storage in this large-scale river corridor. This work showed that both river water and mobile groundwater contaminants could serve as effective tracers of HEFs, thus providing valuable information for evaluating and validating the HEF models. Multimodal residence time distributions with long tails were resulted from the mixture of long and short exchange pathways, which consequently impact the carbon and nutrient cycling within the river corridor. Improved understanding of HEFs using integrated observational and modeling approaches sheds light on

Spatial correlation length of normalized cone data in sand

DEFF Research Database (Denmark)

Firouzianbandpey, Sarah; Griffiths, D. V.; Ibsen, Lars Bo

2014-01-01

The main topic of this study is to assess the anisotropic spatial correlation lengths of a sand layer deposit based on cone penetration testing with pore pressure measurement (CPTu) data. Spatial correlation length can be an important factor in reliability analysis of geotechnical systems, yet it...

Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council

Energy Technology Data Exchange (ETDEWEB)

Kuiper, James A.; Cantwell, Brian J.; Hlava, Kevin J.; Moore, H Robert; Orr, Andrew B.; Zvolanek, Emily A.

2014-02-24

This report, Analysis of Potential Energy Corridors Proposed by the Western Electricity Coordinating Council (WECC), was prepared by the Environmental Science Division of Argonne National Laboratory (Argonne). The intent of WECC’s work was to identify planning-level energy corridors that the Department of Energy (DOE) and its affiliates could study in greater detail. Argonne was tasked by DOE to analyze the WECC Proposed Energy Corridors in five topic areas for use in reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. In compliance with Section 368 of the Energy Policy Act of 2005 (EPAct), the Secretaries of Energy, Agriculture, and the Interior (Secretaries) published a Programmatic Environmental Impact Statement in 2008 to address the proposed designation of energy transport corridors on federal lands in the 11 western states. Subsequently, Records of Decision designating the corridors were issued in 2009 by the Bureau of Land Management (BLM) and the U.S. Forest Service (USFS). The 2012 settlement of a lawsuit, brought by The Wilderness Society and others against the United States, which identified environmental concerns for many of the corridors requires, among other things, periodic reviews of the corridors to assess the need for revisions, deletions, or additions. A 2013 Presidential Memorandum requires the Secretaries to undertake a continuing effort to identify and designate energy corridors. The WECC Proposed Energy Corridors and their analyses in this report provide key information for reviewing and revising existing corridors, as well as designating additional energy corridors in the 11 western states. Load centers and generation hubs identified in the WECC analysis, particularly as they reflect renewable energy development, would be useful in reviewing and potentially updating the designated Section 368 corridor network. Argonne used Geographic Information System (GIS) technology to

Of corridors and chains: translocal developmental impact of academic mobility between China and Germany

NARCIS (Netherlands)

Leung, W.H.M.

2011-01-01

This paper examines the impact of transnational geographical mobility among Chinese and German scholars using the concepts of 'development corridors' and 'development chains'. A temporal-spatial analysis of two case studies – (1) a multi-generation actor-based network of social scientists and (2)

Spatial variability of correlated color temperature of lightning channels

Directory of Open Access Journals (Sweden)

Nobuaki Shimoji

Full Text Available In this paper, we present the spatial variability of the correlated color temperature of lightning channel shown in a digital still image. In order to analyze the correlated color temperature, we calculated chromaticity coordinates of the lightning channels in the digital still image. From results, the spatial variation of the correlated color temperature of the lightning channel was confirmed. Moreover, the results suggest that the correlated color temperature and peak current of the lightning channels are related to each other. Keywords: Lightning, Color analysis, Correlated color temperature, Chromaticity coordinate, CIE 1931 xy-chromaticity diagram

A DATA FIELD METHOD FOR URBAN REMOTELY SENSED IMAGERY CLASSIFICATION CONSIDERING SPATIAL CORRELATION

Directory of Open Access Journals (Sweden)

Y. Zhang

2016-06-01

Full Text Available Spatial correlation between pixels is important information for remotely sensed imagery classification. Data field method and spatial autocorrelation statistics have been utilized to describe and model spatial information of local pixels. The original data field method can represent the spatial interactions of neighbourhood pixels effectively. However, its focus on measuring the grey level change between the central pixel and the neighbourhood pixels results in exaggerating the contribution of the central pixel to the whole local window. Besides, Geary’s C has also been proven to well characterise and qualify the spatial correlation between each pixel and its neighbourhood pixels. But the extracted object is badly delineated with the distracting salt-and-pepper effect of isolated misclassified pixels. To correct this defect, we introduce the data field method for filtering and noise limitation. Moreover, the original data field method is enhanced by considering each pixel in the window as the central pixel to compute statistical characteristics between it and its neighbourhood pixels. The last step employs a support vector machine (SVM for the classification of multi-features (e.g. the spectral feature and spatial correlation feature. In order to validate the effectiveness of the developed method, experiments are conducted on different remotely sensed images containing multiple complex object classes inside. The results show that the developed method outperforms the traditional method in terms of classification accuracies.

Green corridors and network design

DEFF Research Database (Denmark)

Panagakos, George

2016-01-01

The purpose of this chapter is to investigate the relation between the Trans-European Transport Network (TEN-T) and the green corridor concept. First, the need is established for a corridor governance structure that enables the close cooperation among the numerous stakeholders from both the public...

Energy corridors European Union and Neighbouring countries

International Nuclear Information System (INIS)

Van Oostvoorn, F.; Hafner, Manfred; Vailati, Ricardo; Wietschel, Martin

2007-08-01

The ENCOURAGED (Energy corridor optimisation for European markets of gas, electricity and hydrogen) project has been launched in beginning 2005 to identify and assess the economically optimal energy corridors between European Union (EU) and neighbouring countries. The objectives of the project are to: Assess the economic optimal energy (electricity, gas and hydrogen) corridors and related network infrastructure for connecting the EU with its neighbouring countries and regions; Identify, quantify and evaluate the barriers to and potential benefits of building optimal energy corridors connecting the EU with its neighbours; Propose necessary policy measures to implement the recommended energy corridors with a focus on investment and the geopolitical framework; Organise stakeholder workshops and seminars to discuss the results and findings and reach consensus among scientists, stakeholders and non-governmental organizations and validate project results

Long Island Smart Energy Corridor

Energy Technology Data Exchange (ETDEWEB)

Mui, Ming [Long Island Power Authority, Uniondale, NY (United States)

2015-02-04

The Long Island Power Authority (LIPA) has teamed with Stony Brook University (Stony Brook or SBU) and Farmingdale State College (Farmingdale or FSC), two branches of the State University of New York (SUNY), to create a “Smart Energy Corridor.” The project, located along the Route 110 business corridor on Long Island, New York, demonstrated the integration of a suite of Smart Grid technologies from substations to end-use loads. The Smart Energy Corridor Project included the following key features: -TECHNOLOGY: Demonstrated a full range of smart energy technologies, including substations and distribution feeder automation, fiber and radio communications backbone, advanced metering infrastructure (AM”), meter data management (MDM) system (which LIPA implemented outside of this project), field tools automation, customer-level energy management including automated energy management systems, and integration with distributed generation and plug-in hybrid electric vehicles. -MARKETING: A rigorous market test that identified customer response to an alternative time-of-use pricing plan and varying levels of information and analytical support. -CYBER SECURITY: Tested cyber security vulnerabilities in Smart Grid hardware, network, and application layers. Developed recommendations for policies, procedures, and technical controls to prevent or foil cyber-attacks and to harden the Smart Grid infrastructure. -RELIABILITY: Leveraged new Smart Grid-enabled data to increase system efficiency and reliability. Developed enhanced load forecasting, phase balancing, and voltage control techniques designed to work hand-in-hand with the Smart Grid technologies. -OUTREACH: Implemented public outreach and educational initiatives that were linked directly to the demonstration of Smart Grid technologies, tools, techniques, and system configurations. This included creation of full-scale operating models demonstrating application of Smart Grid technologies in business and residential

Spatial Correlation of PAN UWB-MIMO Channel Including User Dynamics

DEFF Research Database (Denmark)

Wang, Yu; Kovacs, Istvan Zsolt; Pedersen, Gert Frølund

. It is found the channel shows spatial correlated wideband power, and spatial uncorrelated complex channel coefficients at different frequencies and delays with respect to a correlation coefficient threshold of 0.7. The Kronecker model is proved not suitable for the investigated scenarios. The MIMO UWB channel......In this paper we present and analyze spatial correlation properties of indoor 4x2 MIMO UWB channels in personal area network (PAN) scenarios. The presented results are based on measurement of radio links between an access point like device and a hand held or belt mounted device with dynamic user...

FINAL PROJECT REPORT: A Geophysical Characterization & Monitoring Strategy for Determining Hydrologic Processes in the Hyporheic Corridor at the Hanford 300-Area

Energy Technology Data Exchange (ETDEWEB)

Lee Slater

2011-08-15

The primary objective of this research was to advance the prediction of solute transport between the Uranium contaminated Hanford aquifer and the Columbia River at the Hanford 300 Area by improving understanding of how fluctuations in river stage, combined with subsurface heterogeneity, impart spatiotemporal complexity to solute exchange along the Columbia River corridor. Our work explored the use of continuous waterborne electrical imaging (CWEI), in conjunction with fiber-optic distributed temperature sensor (FO-DTS) and time-lapse resistivity monitoring, to improve the conceptual model for how groundwater/surface water exchange regulates uranium transport. We also investigated how resistivity and induced polarization can be used to generate spatially rich estimates of the variation in depth to the Hanford-Ringold (H-R) contact between the river and the 300 Area Integrated Field Research Challenge (IFRC) site. Inversion of the CWEI datasets (a data rich survey containing ~60,000 measurements) provided predictions of the distributions of electrical resistivity and polarizability, from which the spatial complexity of the primary hydrogeologic units along the river corridor was reconstructed. Variation in the depth to the interface between the overlying coarse-grained, high permeability Hanford Formation and the underlying finer-grained, less permeable Ringold Formation, an important contact that limits vertical migration of contaminants, has been resolved along ~3 km of the river corridor centered on the IFRC site in the Hanford 300 Area. Spatial variability in the thickness of the Hanford Formation captured in the CWEI datasets indicates that previous studies based on borehole projections and drive-point and multi-level sampling likely overestimate the contributing area for uranium exchange within the Columbia River at the Hanford 300 Area. Resistivity and induced polarization imaging between the river and the 300 Area IFRC further imaged spatial variability in

Measurement of spatial correlation functions using image processing techniques

International Nuclear Information System (INIS)

Berryman, J.G.

1985-01-01

A procedure for using digital image processing techniques to measure the spatial correlation functions of composite heterogeneous materials is presented. Methods for eliminating undesirable biases and warping in digitized photographs are discussed. Fourier transform methods and array processor techniques for calculating the spatial correlation functions are treated. By introducing a minimal set of lattice-commensurate triangles, a method of sorting and storing the values of three-point correlation functions in a compact one-dimensional array is developed. Examples are presented at each stage of the analysis using synthetic photographs of cross sections of a model random material (the penetrable sphere model) for which the analytical form of the spatial correlations functions is known. Although results depend somewhat on magnification and on relative volume fraction, it is found that photographs digitized with 512 x 512 pixels generally have sufficiently good statistics for most practical purposes. To illustrate the use of the correlation functions, bounds on conductivity for the penetrable sphere model are calculated with a general numerical scheme developed for treating the singular three-dimensional integrals which must be evaluated

Developing high-resolution spatial data of migration corridors for avian species of concern in regions of high potential wind development

Energy Technology Data Exchange (ETDEWEB)

Katzner, Todd [West Virginia Univ., Morgantown, WV (United States)

2014-06-15

The future of the US economy, our national security, and our environmental quality all depend on decreasing our reliance on foreign oil and on fossil fuels. An essential component of decreasing this reliance is the development of alternative energy sources. Wind power is among the most important alternative energy sources currently available, and the mid-Atlantic region is a primary focus for wind power development. In addition to being important to the development of wind power, the mid-Atlantic region holds a special responsibility for the conservation of the eastern North America's golden eagles (Aquila chrysaetos). This small population breeds in northeastern Canada, winters in the southern Appalachians, and nearly all of these birds pass through the mid-Atlantic region twice each year. Movement of these birds is not random and, particularly during spring and autumn, migrating golden eagles concentrate in a narrow 30-50 mile wide corridor in central Pennsylvania. Thus, because the fate of these rare birds may depend on responsible management of the habitat they use it is critical to use research to identify ways to mitigate prospective impacts on this and similar raptor species. The goal of this project was to develop high-resolution spatial risk maps showing migration corridors of and habitat use by eastern golden eagles in regions of high potential for wind development. To accomplish this, we first expanded existing models of raptor migration for the eastern USA to identify broad-scale migration patterns. We then used data from novel high-resolution tracking devices to discover routes of passage and detailed flight behavior of individual golden eagles throughout the eastern USA. Finally, we integrated these data and models to predict population-level migration patterns and individual eagle flight behavior on migration. We then used this information to build spatially explicit, probabilistic maps showing relative risk to birds from wind development. This

I-880 Integrated Corridor Management Concept of Operation : Final Submittal: Concept of Operations for the I-880 Corridor in Oakland, California

Science.gov (United States)

2008-03-31

This report describes the draft Concept of Operations that has been developed for the Integrated Corridor Mobility (ICM) program by the I-880 corridor team. The I-880 corridor team has defined this Concept of Operations (ConOps) based on two primary ...

Forest corridors maintain historical gene flow in a tiger metapopulation in the highlands of central India.

Science.gov (United States)

Sharma, Sandeep; Dutta, Trishna; Maldonado, Jesús E; Wood, Thomas C; Panwar, Hemendra Singh; Seidensticker, John

2013-09-22

Understanding the patterns of gene flow of an endangered species metapopulation occupying a fragmented habitat is crucial for landscape-level conservation planning and devising effective conservation strategies. Tigers (Panthera tigris) are globally endangered and their populations are highly fragmented and exist in a few isolated metapopulations across their range. We used multi-locus genotypic data from 273 individual tigers (Panthera tigris tigris) from four tiger populations of the Satpura-Maikal landscape of central India to determine whether the corridors in this landscape are functional. This 45 000 km(2) landscape contains 17% of India's tiger population and 12% of its tiger habitat. We applied Bayesian and coalescent-based analyses to estimate contemporary and historical gene flow among these populations and to infer their evolutionary history. We found that the tiger metapopulation in central India has high rates of historical and contemporary gene flow. The tests for population history reveal that tigers populated central India about 10 000 years ago. Their population subdivision began about 1000 years ago and accelerated about 200 years ago owing to habitat fragmentation, leading to four spatially separated populations. These four populations have been in migration-drift equilibrium maintained by high gene flow. We found the highest rates of contemporary gene flow in populations that are connected by forest corridors. This information is highly relevant to conservation practitioners and policy makers, because deforestation, road widening and mining are imminent threats to these corridors.

Spatial correlation genetic algorithm for fractal image compression

International Nuclear Information System (INIS)

Wu, M.-S.; Teng, W.-C.; Jeng, J.-H.; Hsieh, J.-G.

2006-01-01

Fractal image compression explores the self-similarity property of a natural image and utilizes the partitioned iterated function system (PIFS) to encode it. This technique is of great interest both in theory and application. However, it is time-consuming in the encoding process and such drawback renders it impractical for real time applications. The time is mainly spent on the search for the best-match block in a large domain pool. In this paper, a spatial correlation genetic algorithm (SC-GA) is proposed to speed up the encoder. There are two stages for the SC-GA method. The first stage makes use of spatial correlations in images for both the domain pool and the range pool to exploit local optima. The second stage is operated on the whole image to explore more adequate similarities if the local optima are not satisfied. With the aid of spatial correlation in images, the encoding time is 1.5 times faster than that of traditional genetic algorithm method, while the quality of the retrieved image is almost the same. Moreover, about half of the matched blocks come from the correlated space, so fewer bits are required to represent the fractal transform and therefore the compression ratio is also improved

Methodology for Collision Risk Assessment of an Airspace Flow Corridor Concept

Science.gov (United States)

Zhang, Yimin

This dissertation presents a methodology to estimate the collision risk associated with a future air-transportation concept called the flow corridor. The flow corridor is a Next Generation Air Transportation System (NextGen) concept to reduce congestion and increase throughput in en-route airspace. The flow corridor has the potential to increase throughput by reducing the controller workload required to manage aircraft outside the corridor and by reducing separation of aircraft within corridor. The analysis in this dissertation is a starting point for the safety analysis required by the Federal Aviation Administration (FAA) to eventually approve and implement the corridor concept. This dissertation develops a hybrid risk analysis methodology that combines Monte Carlo simulation with dynamic event tree analysis. The analysis captures the unique characteristics of the flow corridor concept, including self-separation within the corridor, lane change maneuvers, speed adjustments, and the automated separation assurance system. Monte Carlo simulation is used to model the movement of aircraft in the flow corridor and to identify precursor events that might lead to a collision. Since these precursor events are not rare, standard Monte Carlo simulation can be used to estimate these occurrence rates. Dynamic event trees are then used to model the subsequent series of events that may lead to collision. When two aircraft are on course for a near-mid-air collision (NMAC), the on-board automated separation assurance system provides a series of safety layers to prevent the impending NNAC or collision. Dynamic event trees are used to evaluate the potential failures of these layers in order to estimate the rare-event collision probabilities. The results show that the throughput can be increased by reducing separation to 2 nautical miles while maintaining the current level of safety. A sensitivity analysis shows that the most critical parameters in the model related to the overall

GEOMETRIC CONTEXT AND ORIENTATION MAP COMBINATION FOR INDOOR CORRIDOR MODELING USING A SINGLE IMAGE

Directory of Open Access Journals (Sweden)

A. B. Jahromi

2016-06-01

Full Text Available Since people spend most of their time indoors, their indoor activities and related issues in health, security and energy consumption have to be understood. Hence, gathering and representing spatial information of indoor spaces in form of 3D models become very important. Considering the available data gathering techniques with respect to the sensors cost and data processing time, single images proved to be one of the reliable sources. Many of the current single image based indoor space modeling methods are defining the scene as a single box primitive. This domain-specific knowledge is usually not applicable in various cases where multiple corridors are joined at one scene. Here, we addressed this issue by hypothesizing-verifying multiple box primitives which represents the indoor corridor layout. Middle-level perceptual organization is the foundation of the proposed method, which relies on finding corridor layout boundaries using both detected line segments and virtual rays created by orthogonal vanishing points. Due to the presence of objects, shadows and occlusions, a comprehensive interpretation of the edge relations is often concealed. This necessitates the utilization of virtual rays to create a physically valid layout hypothesis. Many of the former methods used Orientation Map or Geometric Context to evaluate their proposed layout hypotheses. Orientation map is a map that reveals the local belief of region orientations computed from line segments, and in a segmented image geometric context uses color, texture, edge, and vanishing point cues to estimate the likelihood of each possible label for all super-pixels. Here, the created layout hypotheses are evaluated by an objective function which considers the fusion of orientation map and geometric context with respect to the horizontal viewing angle at each image pixel. Finally, the best indoor corridor layout hypothesis which gets the highest score from the scoring function will be selected

Correlation of Spatially Filtered Dynamic Speckles in Distance Measurement Application

International Nuclear Information System (INIS)

Semenov, Dmitry V.; Nippolainen, Ervin; Kamshilin, Alexei A.; Miridonov, Serguei V.

2008-01-01

In this paper statistical properties of spatially filtered dynamic speckles are considered. This phenomenon was not sufficiently studied yet while spatial filtering is an important instrument for speckles velocity measurements. In case of spatial filtering speckle velocity information is derived from the modulation frequency of filtered light power which is measured by photodetector. Typical photodetector output is represented by a narrow-band random noise signal which includes non-informative intervals. Therefore more or less precious frequency measurement requires averaging. In its turn averaging implies uncorrelated samples. However, conducting research we found that correlation is typical property not only of dynamic speckle patterns but also of spatially filtered speckles. Using spatial filtering the correlation is observed as a response of measurements provided to the same part of the object surface or in case of simultaneously using several adjacent photodetectors. Found correlations can not be explained using just properties of unfiltered dynamic speckles. As we demonstrate the subject of this paper is important not only from pure theoretical point but also from the point of applied speckle metrology. E.g. using single spatial filter and an array of photodetector can greatly improve accuracy of speckle velocity measurements

Reclaiming deserted corridors: Rights of way as common property resources

International Nuclear Information System (INIS)

Brown, D.T.

1993-01-01

In Canada, power line transmission corridors are administered and maintained by provincial crown utilities. These corridors have fragmented natural habitats, destroyed biota, and disrupted geological and hydrologic systems. The practices used by utilities to maintain their rights-of-way tend to worsen the environmental and social context of the localities affected by the corridors. If the corridors are considered as common resources, and if co-management of these resources is undertaken involving the utilities and the communities affected by the corridors, public rights-of-way would be created which would have environmental benefits. These corridors would have a recreational potential and could be managed so as to reduce considerably the negative impacts presently generated by current right-of-way management practices. The use of local residents in this management process could ensure that the use of the corridors harmonizes with local needs. Among the obstacles to the co-management of these corridors are the badly defined policies of secondary land use, the restrictions on vegetation maintenance in utility corridors, lengthy approvals processes, and concerns about public liability. To make co-management of these corridors a reality, new policy structures and new procedures have to be developed in cooperation with the utilities and the affected communities. 14 refs., 1 fig

Urban Power Line Corridors as Novel Habitats for Grassland and Alien Plant Species in South-Western Finland.

Directory of Open Access Journals (Sweden)

Jussi Lampinen

Full Text Available Regularly managed electric power line corridors may provide habitats for both early-successional grassland plant species and disturbance-dependent alien plant species. These habitats are especially important in urban areas, where they can help conserve native grassland species and communities in urban greenspace. However, they can also provide further footholds for potentially invasive alien species that already characterize urban areas. In order to implement power line corridors into urban conservation, it is important to understand which environmental conditions in the corridors favor grassland species and which alien species. Likewise it is important to know whether similar environmental factors in the corridors control the species composition of the two groups. We conducted a vegetation study in a 43 kilometer long urban power line corridor network in south-western Finland, and used generalized linear models and distance-based redundancy analysis to determine which environmental factors best predict the occurrence and composition of grassland and alien plant species in the corridors. The results imply that old corridors on dry soils and steep slopes characterized by a history as open areas and pastures are especially suitable for grassland species. Corridors suitable for alien species, in turn, are characterized by productive soils and abundant light and are surrounded by a dense urban fabric. Factors controlling species composition in the two groups are somewhat correlated, with the most important factors including light abundance, soil moisture, soil calcium concentration and soil productivity. The results have implications for grassland conservation and invasive alien species control in urban areas.

Comprehensive highway corridor planning with sustainability indicators.

Science.gov (United States)

2011-10-01

"The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pr...

Landscape susceptibility, hazard and risk assessments along pipeline corridors in Canada

Energy Technology Data Exchange (ETDEWEB)

Blais-Stevens, A.; Couture, R.; Page, A. [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada; Koch, J.; Clague, J.J. [Simon Fraser Univ., Burnaby, BC (Canada); Lipovsky, P.S. [Yukon Geological Survey, Whitehorse, YT (Canada)

2010-07-01

This article discussed work that was carried out to inventory landslides and assess hazards along two proposed gas-pipeline routes in the North. Landslide inventories and hazard assessments are necessary to quantify and qualify the risk of environmental impacts from landslides on linear infrastructure. The Yukon Alaska Highway Pipeline and the Mackenzie Gas Project Pipeline, which will both be over 800 kilometres in length, will cross harsh landscapes characterized by permafrost terrain and will be at risk from geological hazards, including landslides with debris flows, earthquakes, subsidence, and permafrost degradation. The work involved inventorying and mapping landslides via aerial photography and field visits to identify the frequency-magnitude relationships for debris flow fans along the route and the creation of qualitative parametric landslide maps for both proposed pipeline corridors. A good correlation was found between actual landslide distribution and the landslide susceptibility maps. For the Mackenzie Valley Pipeline Corridor, most landslides have occurred in fine unconsolidated sediments and shallow slopes. Landslides in the Yukon Alaska Highway Corridor mostly happened in unconsolidated sediments, but a few took place in bedrock with high relief. The preliminary investigation revealed that a slope hazard exists in both corridors and must be taken into account during pipeline development. The results are intended to facilitate better decision-making for planning, constructing, and maintaining safe and economically viable pipeline routes in Northern Canada. The mapping methodology was outlined. 13 refs., 1 tab., 6 figs.

FRACOR-software toolbox for deterministic mapping of fracture corridors in oil fields on AutoCAD platform

Science.gov (United States)

Ozkaya, Sait I.

2018-03-01

Fracture corridors are interconnected large fractures in a narrow sub vertical tabular array, which usually traverse entire reservoir vertically and extended for several hundreds of meters laterally. Fracture corridors with their huge conductivities constitute an important element of many fractured reservoirs. Unlike small diffuse fractures, actual fracture corridors must be mapped deterministically for simulation or field development purposes. Fracture corridors can be identified and quantified definitely with borehole image logs and well testing. However, there are rarely sufficient image logs or well tests, and it is necessary to utilize various fracture corridor indicators with varying degrees of reliability. Integration of data from many different sources, in turn, requires a platform with powerful editing and layering capability. Available commercial reservoir characterization software packages, with layering and editing capabilities, can be cost intensive. CAD packages are far more affordable and may easily acquire the versatility and power of commercial software packages with addition of a small software toolbox. The objective of this communication is to present FRACOR, a software toolbox which enables deterministic 2D fracture corridor mapping and modeling on AutoCAD platform. The FRACOR toolbox is written in AutoLISPand contains several independent routines to import and integrate available fracture corridor data from an oil field, and export results as text files. The resulting fracture corridor maps consists mainly of fracture corridors with different confidence levels from combination of static and dynamic data and exclusion zones where no fracture corridor can exist. The exported text file of fracture corridors from FRACOR can be imported into an upscaling programs to generate fracture grid for dual porosity simulation or used for field development and well planning.

76 FR 34139 - Northeast Corridor Safety Committee; Meeting Postponement

Science.gov (United States)

2011-06-10

.... 2] Northeast Corridor Safety Committee; Meeting Postponement AGENCY: Federal Railroad Administration... announced the first meeting of the Northeast Corridor Safety Committee, a Federal Advisory Committee... future date. DATES: The meeting of the Northeast Corridor Safety Committee scheduled to commence on...

Estimates of spatial correlation in volcanic tuff, Yucca Mountain, Nevada: Yucca Mountain Site Characterization Project

International Nuclear Information System (INIS)

Rautman, C.A.

1991-02-01

The spatial correlation structure of volcanic tuffs at and near the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada, is estimated using samples obtained from surface outcrops and drill holes. Data are examined for four rock properties: porosity, air permeability, saturated hydraulic conductivity, and dry bulk density. Spatial continuity patterns are identified in both lateral and vertical (stratigraphic) dimensions. The data are examined for the Calico Hills tuff stratigraphic unit and also without regard for stratigraphy. Variogram models fitted to the sample data from the tuffs of Calico Hills indicate that porosity is correlated laterally over distances of up to 3000 feet. If air permeability and saturated conductivity values are viewed as semi-interchangeable for purposes of identifying spatial structure, the data suggest a maximum range of correlation of 300 to 500 feet without any obvious horizontal to vertical anisotropy. Continuity exists over vertical distances of roughly 200 feet. Similar variogram models fitted to sample data taken from vertical drill holes without regard for stratigraphy suggest that correlation exists over distances of 500 to 800 feet for each rock property examined. Spatial correlation of rock properties violates the sample-independence assumptions of classical statistics to a degree not usually acknowledged. In effect, the existence of spatial structure reduces the ''equivalent'' number of samples below the number of physical samples. This reduction in the effective sampling density has important implications for site characterization for the Yucca Mountain Project. 19 refs., 43 figs., 5 tabs

Identifying Corridors among Large Protected Areas in the United States.

Directory of Open Access Journals (Sweden)

R Travis Belote

Full Text Available Conservation scientists emphasize the importance of maintaining a connected network of protected areas to prevent ecosystems and populations from becoming isolated, reduce the risk of extinction, and ultimately sustain biodiversity. Keeping protected areas connected in a network is increasingly recognized as a conservation priority in the current era of rapid climate change. Models that identify suitable linkages between core areas have been used to prioritize potentially important corridors for maintaining functional connectivity. Here, we identify the most "natural" (i.e., least human-modified corridors between large protected areas in the contiguous Unites States. We aggregated results from multiple connectivity models to develop a composite map of corridors reflecting agreement of models run under different assumptions about how human modification of land may influence connectivity. To identify which land units are most important for sustaining structural connectivity, we used the composite map of corridors to evaluate connectivity priorities in two ways: (1 among land units outside of our pool of large core protected areas and (2 among units administratively protected as Inventoried Roadless (IRAs or Wilderness Study Areas (WSAs. Corridor values varied substantially among classes of "unprotected" non-core land units, and land units of high connectivity value and priority represent diverse ownerships and existing levels of protections. We provide a ranking of IRAs and WSAs that should be prioritized for additional protection to maintain minimal human modification. Our results provide a coarse-scale assessment of connectivity priorities for maintaining a connected network of protected areas.

76 FR 72029 - Multistate Corridor Operations and Management Program

Science.gov (United States)

2011-11-21

... in the FHWA Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511... Multistate Corridor Operations and Management Program as authorized in 23 U.S.C. 511. This notice clarifies... DEPARTMENT OF TRANSPORTATION Federal Highway Administration Multistate Corridor Operations and...

Spatial-Temporal Similarity Correlation between Public Transit Passengers Using Smart Card Data

Directory of Open Access Journals (Sweden)

Hamed Faroqi

2017-01-01

Full Text Available The increasing availability of public transit smart card data has enabled several studies to focus on identifying passengers with similar spatial and/or temporal trip characteristics. However, this paper goes one step further by investigating the relationship between passengers’ spatial and temporal characteristics. For the first time, this paper investigates the correlation of the spatial similarity with the temporal similarity between public transit passengers by developing spatial similarity and temporal similarity measures for the public transit network with a novel passenger-based perspective. The perspective considers the passengers as agents who can make multiple trips in the network. The spatial similarity measure takes into account direction as well as the distance between the trips of the passengers. The temporal similarity measure considers both the boarding and alighting time in a continuous linear space. The spatial-temporal similarity correlation between passengers is analysed using histograms, Pearson correlation coefficients, and hexagonal binning. Also, relations between the spatial and temporal similarity values with the trip time and length are examined. The proposed methodology is implemented for four-day smart card data including 80,000 passengers in Brisbane, Australia. The results show a nonlinear spatial-temporal similarity correlation among the passengers.

Assessing Accessibility and Transport Infrastructure Inequities in Administrative Units in Serbia’s Danube Corridor Based on Multi-Criteria Analysis and Gis Mapping Tools

Directory of Open Access Journals (Sweden)

Ana VULEVIC

2018-02-01

Full Text Available The Danube Regions, especially the sub-national units of governance, must be ready to play an active role in spatial development policies. A precondition for this is good accessibility and the coordinated development of all transport systems in the Danube corridor. The main contribution of this paper is to provide a multi-criteria model for potential decision making related to the evaluation of transportation accessibility in Serbia’s Danube Corridor. Geographic Information Systems (GIS, based on maps, indicate the existing counties’ transport infrastructures inequities (between well-connected and isolated counties in terms of accessibility to central places. Through the research, relevant indicators have been identifi ed. This provides an outline of transportation perspectives regarding the development achieved and also fosters the increase of transportation accessibility in some peripheral Serbian Danube administrative units – counties (Nomenclature of Territorial Units for Statistics level 3 – NUTS 3.

Continuous-wave spatial quantum correlations of light induced by multiple scattering

DEFF Research Database (Denmark)

Smolka, Stephan; Ott, Johan Raunkjær; Huck, Alexander

2012-01-01

and reflectance. Utilizing frequency-resolved quantum noise measurements, we observe that the strength of the spatial quantum correlation function can be controlled by changing the quantum state of an incident bright squeezed-light source. Our results are found to be in excellent agreement with the developed......We present theoretical and experimental results on spatial quantum correlations induced by multiple scattering of nonclassical light. A continuous-mode quantum theory is derived that enables determining the spatial quantum correlation function from the fluctuations of the total transmittance...... theory and form a basis for future research on, e. g., quantum interference of multiple quantum states in a multiple scattering medium....

Molecular corridors and parameterizations of volatility in the chemical evolution of organic aerosols

Directory of Open Access Journals (Sweden)

Y. Li

2016-03-01

Full Text Available The formation and aging of organic aerosols (OA proceed through multiple steps of chemical reaction and mass transport in the gas and particle phases, which is challenging for the interpretation of field measurements and laboratory experiments as well as accurate representation of OA evolution in atmospheric aerosol models. Based on data from over 30 000 compounds, we show that organic compounds with a wide variety of functional groups fall into molecular corridors, characterized by a tight inverse correlation between molar mass and volatility. We developed parameterizations to predict the saturation mass concentration of organic compounds containing oxygen, nitrogen, and sulfur from the elemental composition that can be measured by soft-ionization high-resolution mass spectrometry. Field measurement data from new particle formation events, biomass burning, cloud/fog processing, and indoor environments were mapped into molecular corridors to characterize the chemical nature of the observed OA components. We found that less-oxidized indoor OA are constrained to a corridor of low molar mass and high volatility, whereas highly oxygenated compounds in atmospheric water extend to high molar mass and low volatility. Among the nitrogen- and sulfur-containing compounds identified in atmospheric aerosols, amines tend to exhibit low molar mass and high volatility, whereas organonitrates and organosulfates follow high O : C corridors extending to high molar mass and low volatility. We suggest that the consideration of molar mass and molecular corridors can help to constrain volatility and particle-phase state in the modeling of OA particularly for nitrogen- and sulfur-containing compounds.

Corridor Length and Patch Colonization by a Butterfly Junonia coenia

Energy Technology Data Exchange (ETDEWEB)

Nick Haddad

2000-06-01

Habitat corridors have been proposed to reduce patch isolation and increase population persistence in fragmented landscapes. This study tested whether patch colonization was increased by the presence and various length corridors. The specific butterfly species tested has been shown to use corridors, however, the results indicate that neither the distance between patches or the presence of a corridor influenced colonization.

An Introduction to Macro- Level Spatial Nonstationarity: a Geographically Weighted Regression Analysis of Diabetes and Poverty.

Science.gov (United States)

Siordia, Carlos; Saenz, Joseph; Tom, Sarah E

2012-01-01

Type II diabetes is a growing health problem in the United States. Understanding geographic variation in diabetes prevalence will inform where resources for management and prevention should be allocated. Investigations of the correlates of diabetes prevalence have largely ignored how spatial nonstationarity might play a role in the macro-level distribution of diabetes. This paper introduces the reader to the concept of spatial nonstationarity-variance in statistical relationships as a function of geographical location. Since spatial nonstationarity means different predictors can have varying effects on model outcomes, we make use of a geographically weighed regression to calculate correlates of diabetes as a function of geographic location. By doing so, we demonstrate an exploratory example in which the diabetes-poverty macro-level statistical relationship varies as a function of location. In particular, we provide evidence that when predicting macro-level diabetes prevalence, poverty is not always positively associated with diabetes.

An experimental test of whether habitat corridors affect pollen transfer.

Energy Technology Data Exchange (ETDEWEB)

Townsend, Patricia A.; Levey, Douglas J.

2005-02-01

Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimental landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however

Metro Conservation Corridors

Data.gov (United States)

Minnesota Department of Natural Resources — The Metro Conservation Corridors (MeCC) grow out of the natural resource analysis work done by the DNR in the late '90's, documented in the Metro Greenprint...

Rail transportation corridor analysis report: Deaf Smith County location in the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

1986-10-01

An environmental data base was developed for the purpose of preliminary siting of potential rail access corridors between existing rail lines and the potential repository site in Deaf Smith County, Texas. The categories of the data base were environmental conditions considered significant in rail line construction and operation. These included land cover, population areas, slope, surface hydrology, cultivated prime agricultural lands, cultural features, and utility rights-of-way. The categories were divided into avoidance, constraint, and opportunity features, and the constraint features were then weighted for environmental impact potential. An environmental screening analysis using the computerized Geographical Information System (GIS) was then performed. The analysis involved applying the GIS overlay process to the various constraint data categories to produce a composite constraint map of the study area. The composite constraint map, color coded for various levels of constraint to corridor siting, was subsequently used as a guide for the selection of a series of alternative corridors. By means of a further application of GIS procedures, the corridor alternatives were statistically analyzed for adherence to corridor selection guidelines. In addition, a supplementary analysis was performed to compare the alternatives in terms of four impact categories: road crossings, construction costs, degree of land disruption, and population impact. The statistical and supplementary impact analyses led to a preliminary selection of a preferred corridor. The corridor assessment process indicated the importance of analyzing alternative trade-offs, as well as the need for more detailed investigation of certain conditions and a detailed comparison of alternatives prior to final corridor siting

The actual relevance of ecological corridors in nature conservation

Directory of Open Access Journals (Sweden)

Ćurčić Nina B.

2013-01-01

Full Text Available The paper considers theoretical and applied foundations of the concept of the ecological corridors in nature conservation. Their relevance comes from recent ecological phenomenon of habitat fragmentation which is rapidly increasing during last decades. Habitat fragmentation is one of the main threats to richness and diversity of wildlife. Ecological corridors can mitigate the loss and fragmentation of habitat. Corridors perform as “bridges” between habitats for species and they provide a flow of the natural or even anthropogenic caused disturbances. In this paper we will present the meaning and significance of ecological corridors in nature conservation, as well as types of ecological corridors and their ecological benefits. Methodological and practical approaches in nature protection system in Serbia are included. [Projekat Ministarstva nauke Republike Srbije, br. 47007 i br. 176008

River Corridor Easements

Data.gov (United States)

Vermont Center for Geographic Information — A River Corridor Easement (RCE) is an area of conserved land adjacent to a river or stream that was conserved to permanently protect the lateral area the river needs...

Characterizing short-range vs. long-range spatial correlations in dislocation distributions

International Nuclear Information System (INIS)

Chevy, Juliette; Fressengeas, Claude; Lebyodkin, Mikhail; Taupin, Vincent; Bastie, Pierre; Duval, Paul

2010-01-01

Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.

Characterizing short-range vs. long-range spatial correlations in dislocation distributions

Energy Technology Data Exchange (ETDEWEB)

Chevy, Juliette, E-mail: juliette.chevy@gmail.com [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)] [Laboratoire Science et Ingenierie des Materiaux et Procedes, Grenoble INP-CNRS-UJF, BP 75, 38402 St. Martin d' Heres Cedex (France); Fressengeas, Claude; Lebyodkin, Mikhail; Taupin, Vincent [Laboratoire de Physique et Mecanique des Materiaux, Universite Paul Verlaine-Metz/CNRS, Ile du Saulcy, 57045 Metz Cedex (France); Bastie, Pierre [Laboratoire de Spectrometrie Physique, BP 87, 38402 St. Martin d' Heres Cedex (France)] [Institut Laue Langevin, BP 156, 38042 Grenoble Cedex 9 (France); Duval, Paul [Laboratoire de Glaciologie et Geophysique de l' Environnement-CNRS, 54 rue Moliere, 38402 St. Martin d' Heres (France)

2010-03-15

Hard X-ray diffraction experiments have provided evidence of a strongly heterogeneous distribution of dislocation densities along the axis of cylindrical ice single crystals oriented for basal slip in torsion creep. The dislocation arrangements showed a complex scale-invariant character, which was analyzed by means of statistical and multifractal techniques. A trend to decreasing autocorrelation of the dislocation distribution was observed as deformation proceeds. At low strain levels, long-range spatial correlations control the distribution, but short-range correlations in relation with cross-slip progressively prevail when strain increases. This trend was reproduced by a model based on field dislocation dynamics, a theory accounting for both long-range elastic interactions and short-range interactions through transport of dislocation densities.

Habitat corridor utilization by the gray mouse lemur, Microcebus ...

African Journals Online (AJOL)

For this, we trapped M. murinus in four forest fragments and mixed tree plantations between the fragments. One of the corridors was ... During four years of study, only one male M.murinus used the Melaleuca corridor, while several M. murinus were caught in the Eucalyptus and the Acacia corridor in 2013. The density of the ...

77 FR 3326 - Northeast Corridor Safety Committee; Notice of Meeting

Science.gov (United States)

2012-01-23

.... 3] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announced the first meeting of the Northeast Corridor Safety Committee, a Federal...

76 FR 32391 - Northeast Corridor Safety Committee; Notice of Meeting

Science.gov (United States)

2011-06-06

.... 1] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee Meeting. SUMMARY: FRA announces the first meeting of the Northeast Corridor Safety Committee, a...

77 FR 20690 - Northeast Corridor Safety Committee; Notice of Meeting

Science.gov (United States)

2012-04-05

.... 4] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety... NECSC is made up of stakeholders operating on the Northeast Corridor (NEC), and the purpose of the...

Economic corridor of industrial development in Indonesia

Science.gov (United States)

Berawi, M. A.; Miraj, P.; Sidqi, H.

2017-12-01

Indonesia as an archipelago country categorize its regional development into six corridors from Sumatra, Java, Kalimantan, Sulawesi, Bali-Nusa Tenggara and Papua-Maluku. Currently, industrial development becomes one of the highest contributing factors to the national economic growth. However, each region in the nation experience inequality of development mainly related to the infrastructure sector. Thus, the research aims to develop a sustainable economic corridor by considering the characteristics and its potential. The research uses a qualitative approach through a desk study, benchmarking and in-depth interview. Location Quotient is used for the method of the analysis tool. The results show each characteristic of every corridor in the country. Sumatera as national plantation and processing industry corridor, Java as cyber technology innovation and services center, Kalimantan as national energy reserves and processing, Sulawesi as national aquaculture and processing industry, Bali - Nusa Tenggara as national eco-tourism center, and Papua - Maluku as national ore mining and processing.

Forests in the biogeographical corridors connecting the Fennoscandian shield and the Russian plain: natural features, contemporary status, environmental significance

Directory of Open Access Journals (Sweden)

A. N. Gromtsev

2016-12-01

Full Text Available The results of long-term research on forests in natural biogeographical corridors (territories with forests, mires, inland lakes and other land categories connecting the largest bodies of water in Northern Europe (Baltic Sea-Gulf of Finland and lakes Ladoga and Onego to the White Sea are reported. These corridors link isolated pieces of the Eurasian taiga biome at the boundary between two of Europe’s physiographic divisions – Fennoscandian Shield and Russian Plain. They facilitate the dispersal and migration of plant and animal species. The straight-line terrestrial stretch between the Gulf of Finland and the White Sea is around 320 km, and it falls into three sections in the southern, middle and northern taiga subzones, respectively. The corridors were characterized and assessed as follows: 1 physiographic (landscape features; 2 key natural characteristics (typological structure, quantitative ratios, spatial arrangement, productivity, etc., present-day condition of forests, including data from forest management inventories of the past decade; 3 overall assessment of the forest cover transformation by human impact; 4 current system of protected areas and protective forests, and its capacity to fulfill the functions of the corridors (sufficiency.

Spatially characterizing visitor use and its association with informal trails in Yosemite Valley meadows.

Science.gov (United States)

Walden-Schreiner, Chelsey; Leung, Yu-Fai

2013-07-01

Ecological impacts associated with nature-based recreation and tourism can compromise park and protected area goals if left unrestricted. Protected area agencies are increasingly incorporating indicator-based management frameworks into their management plans to address visitor impacts. Development of indicators requires empirical evaluation of indicator measures and examining their ecological and social relevance. This study addresses the development of the informal trail indicator in Yosemite National Park by spatially characterizing visitor use in open landscapes and integrating use patterns with informal trail condition data to examine their spatial association. Informal trail and visitor use data were collected concurrently during July and August of 2011 in three, high-use meadows of Yosemite Valley. Visitor use was clustered at statistically significant levels in all three study meadows. Spatial data integration found no statistically significant differences between use patterns and trail condition class. However, statistically significant differences were found between the distance visitors were observed from informal trails and visitor activity type with active activities occurring closer to trail corridors. Gender was also found to be significant with male visitors observed further from trail corridors. Results highlight the utility of integrated spatial analysis in supporting indicator-based monitoring and informing management of open landscapes. Additional variables for future analysis and methodological improvements are discussed.

Spatially Characterizing Visitor Use and Its Association with Informal Trails in Yosemite Valley Meadows

Science.gov (United States)

Walden-Schreiner, Chelsey; Leung, Yu-Fai

2013-07-01

Ecological impacts associated with nature-based recreation and tourism can compromise park and protected area goals if left unrestricted. Protected area agencies are increasingly incorporating indicator-based management frameworks into their management plans to address visitor impacts. Development of indicators requires empirical evaluation of indicator measures and examining their ecological and social relevance. This study addresses the development of the informal trail indicator in Yosemite National Park by spatially characterizing visitor use in open landscapes and integrating use patterns with informal trail condition data to examine their spatial association. Informal trail and visitor use data were collected concurrently during July and August of 2011 in three, high-use meadows of Yosemite Valley. Visitor use was clustered at statistically significant levels in all three study meadows. Spatial data integration found no statistically significant differences between use patterns and trail condition class. However, statistically significant differences were found between the distance visitors were observed from informal trails and visitor activity type with active activities occurring closer to trail corridors. Gender was also found to be significant with male visitors observed further from trail corridors. Results highlight the utility of integrated spatial analysis in supporting indicator-based monitoring and informing management of open landscapes. Additional variables for future analysis and methodological improvements are discussed.

GIS-BASED ANALYSIS FOR ASSESSING LANDSLIDE AND DROUGHT HAZARD IN THE CORRIDOR OF MT. MERAPI AND MT. MERBABU NATIONAL PARK, INDONESIA

Directory of Open Access Journals (Sweden)

Hero Marhaento

2016-04-01

Full Text Available A corridor is an area located between two or more protected areas that are important to support the sustainability of the protected areas. This study is aimed at assessing landslide and drought hazard in the corridor area between Mt. Merapi National Park (MMNP and Mt. Merbabu National Park (MMbNP as a part of the corridor management strategy. The corridor area of MMNP and MMbNP comprises four sub-districts in Central Java Province, namely, Sawangan, Selo, Ampel, and Cepogo. A spatial analysis of ArcGIS 10.1 software was used to assess landslide hazard map and the Thorntwaite-Matter Water Balance approach was used to assess drought hazard map. The results have shown that three villages in Cepogo Sub-district and all villages in Selo Sub-district are highly prone to landslide hazard. Furthermore, two villages in Cepogo Sub-district and four villages in Selo Sub-district are prone to drought hazard. This study suggests that these villages should initiate a program called conservation village model based on disaster mitigation for mitigating future landslide and drought disasters.

Determination of spatial continuity of soil lead levels in an urban residential neighborhood

Energy Technology Data Exchange (ETDEWEB)

Shinn, N.J.; Bing-Canar, J.; Cailas, M.; Peneff, N.; Binns, H.J.

2000-01-01

This study uses geostatistical techniques to model and estimate soil lead levels in an urban, residential neighborhood. Sixty-two composite soil samples in a four-block area of brick and stone homes were obtained. The spatial continuity of soil lead levels was modeled with a semi-variogram, which was then used to estimate lead levels at unsampled locations, a process called kriging. Because soil lead levels were spatially correlated, it is likely that a nonrandom process generated the lead distribution found. This finding signifies the existence of lead sources which were tentatively identified on historical maps of the area and from past traffic volume patterns. The distribution of kriged estimates of soil lead levels provides an explanatory tool for exploring and identifying potential sources and may be useful for targeting urban soil abatement efforts.

Integrated risk management of safety and development on transportation corridors

International Nuclear Information System (INIS)

Thekdi, Shital A.; Lambert, James H.

2015-01-01

Prioritization of investments to protect safety and performance of multi-regional transportation networks from adjacent land development is a key concern for infrastructure agencies, land developers, and other stakeholders. Despite ample literature describing relationships between transportation and land use, no evidence-based methods exist for monitoring corridor needs on a large scale. Risk analysis is essential to the preservation of system safety and capacity, including avoidance of costly retrofits, regret, and belated action. This paper introduces the Corridor Trace Analysis (CTA) for prioritizing corridor segments that are vulnerable to adjacent land development. The method integrates several components: (i) estimation of likelihood of adjacent land development, using influence diagram and rule-based modeling, (ii) characterization of access point density using geospatial methods, and (iii) plural-model evaluation of corridors, monitoring indices of land development likelihood, access point densities, and traffic volumes. The results inform deployment of options that include closing access points, restricting development, and negotiation of agencies and developers. The CTA method is demonstrated on a region encompassing 6000 centerline miles (about 10,000 km) of transportation corridors. The method will be of interest to managers investing in safety and performance of infrastructure systems, balancing safety, financial, and other criteria of concern for diverse stakeholders. - Highlights: • The Corridor Trace Analysis (CTA) method for prioritizing transportation corridors. • The CTA method studies corridors vulnerable to adjacent land development. • The CTA method quantifies the influence of risk scenarios on agency priorities. • The CTA method is demonstrated on 6000 miles of critical transportation corridor

Developing corridor-level truck travel time estimates and other freight performance measures from archived ITS data.

Science.gov (United States)

2009-08-01

The objectives of this research were to retrospectively study the feasibility for using truck transponder data to produce freight corridor performance measures (travel times) and real-time traveler information. To support this analysis, weigh-in-moti...

Mapping High Biomass Corridors for Climate and Biodiversity Co-Benefits

Science.gov (United States)

Jantz, P.; Goetz, S. J.; Laporte, N. T.

2013-12-01

A key issue in global conservation is how climate mitigation activities can secure biodiversity co-benefits. Tropical deforestation releases significant amounts of CO2 to the atmosphere and results in widespread biodiversity loss. The dominant strategy for forest conservation has been protected area designation. However, maintaining biodiversity in protected areas requires ecological exchange with ecosystems in which they are embedded. At current funding levels, existing conservation strategies are unlikely to prevent further loss of connectivity between protected areas and surrounding landscapes. The emergence of REDD+, a mechanism for funding carbon emissions reductions from deforestation in developing countries, suggests an alignment of goals and financial resources for protecting forest carbon, maintaining biodiversity in protected areas, and minimizing loss of forest ecosystem services. Identifying, protecting and sustainably managing vegetation carbon stocks between protected areas can provide both climate mitigation benefits through avoided CO2 emissions from deforestation and biodiversity benefits through the targeted protection of forests that maintain connectivity between protected areas and surrounding ecosystems. We used a high resolution, pan-tropical map of vegetation carbon stocks derived from MODIS, GLAS lidar and field measurements to map corridors that traverse areas of highest aboveground biomass between protected areas. We mapped over 13,000 corridors containing 49 GtC, accounting for 14% of unprotected vegetation carbon stock in the tropics. In the majority of cases, carbon density in corridors was commensurate with that of the protected areas they connect, suggesting significant opportunities for achieving climate mitigation and biodiversity co-benefits. To further illustrate the utility of this approach, we conducted a multi-criteria analysis of corridors in the Brazilian Amazon, identifying high biodiversity, high vegetation carbon stock

Intermodal Logistics Centres and Freight Corridors – Concepts and Trends

Directory of Open Access Journals (Sweden)

Norbert Wagener

2017-09-01

Full Text Available . Background: The development of international freight corridors, as the Trans European Network and new rail and inland shipping corridors in Asia and Africa, require efficient logistics centres along these corridors which serve as intermodal interfaces and provide a variety of different logistics service functions. The definition of the term logistics centre differs between countries and implies different functionalities. Locations are often selected randomly and business models are opportunity driven, especially in highly dynamic and less regulated new emerging economies. In particular Freight Villages as a special form of logistics centres have a high impact on regional development and serve as cargo generator for freight corridors. Consideration of general principles how to establish Freight Villages could improve the effectiveness of these logistics centres along freight corridors. Methods: Based on a literature review a comprehensive and hierarchical definition of logistics centres will be discussed and applied. From experiences in the development of logistics centres in several countries, especially in Germany and Lithuania, challenges and concepts concerning regulatory framework, determination of location and business and financing models are discussed. Results: Concerning the definition of logistics centres a hierarchical definition is applied which comprises different levels of logistics centres depending on the scope of the value adding and the functionality. As general principles for the development of Freight Villages the active role of the state, master planning, objective location finding, participation and co-operation of different stakeholders in the business model and a stepwise scheme for financing are introduced. Major trends for the future development of Freight Villages are the digitalization of supply chains, the application of new intermodal technologies and of innovative telematics systems, solutions for low emission and

Atmospheric pollution in the Tula Industrial Corridor studied using a bio monitor and nuclear analytical techniques

Energy Technology Data Exchange (ETDEWEB)

Martinez C, M. A.; Solis, C.; Andrade, E. [UNAM, Instituto de Fisica, Apdo. Postal 20-364, 01000 Mexico D. F. (Mexico); Beltran H, R. I. [Universidad Autonoma del Estado de Hidalgo, Centro de Investigaciones Quimicas, Carretera Pachuca-Tulancingo Km. 4.5, 42184 Pachuca, Hidalgo (Mexico); Issac O, K. [Universidad Autonoma del Estado de Mexico, Facultad de Medicina, Paseo Tollocan s/n, esq. Jesus Carranza, 50120 Toluca, Estado de Mexico (Mexico); Lucho C, C. A. [Universidad Politecnica de Pachuca, Carretera Pachuca-Cd. Sahagun Km. 20, Hidalgo (Mexico); Lopez R, M. C.; Longoria, L. C. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2011-02-15

This study deals with the application of nuclear analytical techniques to analyze trace elements in the biological monitor Tillandsia usneoides. Biological monitors provides an alternative advantageous way of particulate matter sampling in air pollution studies, since there is no need of special sampling devices, accumulation time can be as long as desired. T. usneoides, which occurs naturally throughout Mexico, was used to monitor air quality of Tula-Vito-Apasco (TVA) industrial corridor at central Mexico. This area is considered one of the critical zones of the country because of atmospheric contaminants high concentration. Particulate matter is regulated by Mexican norms, but its chemical composition is not. Plants were transplanted from a clean environment to four sites at the TVA corridor, and exposed for 12 weeks from February to April 2008. Trace element accumulation of plants was determined by particle induced X-ray emission and neutron activation analysis. Results reveal differences in trace elements distribution among sites in the TVA corridor. Furthermore, anthropogenic elements (S, V) and crustal elements (Ca) in T. usneoides exhibit high levels. Highly toxic elements such as Hg, As and Cr although present at trace levels, showed un enrichment relative to the initial values, when transplanted to the TVA corridor. Results show that monitoring with T. usneoides allows a first approximation of air sources to provide insights of the atmospheric pollution in the TVA corridor. (Author)

Atmospheric pollution in the Tula Industrial Corridor studied using a bio monitor and nuclear analytical techniques

International Nuclear Information System (INIS)

Martinez C, M. A.; Solis, C.; Andrade, E.; Beltran H, R. I.; Issac O, K.; Lucho C, C. A.; Lopez R, M. C.; Longoria, L. C.

2011-01-01

This study deals with the application of nuclear analytical techniques to analyze trace elements in the biological monitor Tillandsia usneoides. Biological monitors provides an alternative advantageous way of particulate matter sampling in air pollution studies, since there is no need of special sampling devices, accumulation time can be as long as desired. T. usneoides, which occurs naturally throughout Mexico, was used to monitor air quality of Tula-Vito-Apasco (TVA) industrial corridor at central Mexico. This area is considered one of the critical zones of the country because of atmospheric contaminants high concentration. Particulate matter is regulated by Mexican norms, but its chemical composition is not. Plants were transplanted from a clean environment to four sites at the TVA corridor, and exposed for 12 weeks from February to April 2008. Trace element accumulation of plants was determined by particle induced X-ray emission and neutron activation analysis. Results reveal differences in trace elements distribution among sites in the TVA corridor. Furthermore, anthropogenic elements (S, V) and crustal elements (Ca) in T. usneoides exhibit high levels. Highly toxic elements such as Hg, As and Cr although present at trace levels, showed un enrichment relative to the initial values, when transplanted to the TVA corridor. Results show that monitoring with T. usneoides allows a first approximation of air sources to provide insights of the atmospheric pollution in the TVA corridor. (Author)

Integrated corridor management : implementation guide and lessons learned.

Science.gov (United States)

2012-02-01

This implementation guide is intended for use by adopters of integrated corridor management (ICM) approaches and strategies to address congestion and travel time reliability issues within specific travel corridors. It introduces the topic of ICM and ...

Operational performance of a congested corridor with lanes dedicated to autonomous vehicle traffic

Directory of Open Access Journals (Sweden)

Zachary Vander Laan

2017-06-01

Full Text Available This paper considers the operational performance impact of autonomous vehicles (AV on a multi-lane freeway corridor with separate lanes dedicated to AV and non-AV traffic. Autonomous vehicle behavior is modeled at the macroscopic level by modifying the fundamental diagram relating hourly traffic flow and vehicle density, a step that is justified by adjusting a parameter from Newell’s car-following model at the microscopic level and transforming back to a macroscopic representation. The model is applied to the I-95 corridor between Washington, DC and Baltimore, MD during the PM peak period, where the impact of introducing a managed AV-only lane is assessed at varying penetration rates of autonomous vehicles. The results show that the overall corridor performance metrics improve with increasing penetration rates up to 30%, 40% or 50% (depending on the underlying assumptions that govern AV behavior, after which the performance deteriorates drastically. Implications of the results are discussed in light of the per-lane and aggregated metrics, and future directions for research are proposed.

Pollination and reproduction of a self-incompatible forest herb in hedgerow corridors and forest patches.

Science.gov (United States)

Schmucki, Reto; de Blois, Sylvie

2009-07-01

Habitat-corridors are assumed to counteract the negative impacts of habitat loss and fragmentation, but their efficiency in doing so depends on the maintenance of ecological processes in corridor conditions. For plants dispersing in linear habitats, one of these critical processes is the maintenance of adequate pollen transfer to insure seed production within the corridor. This study focuses on a common, self-incompatible forest herb, Trillium grandiflorum, to assess plant-pollinator interactions and the influence of spatial processes on plant reproduction in hedgerow corridors compared to forests. First, using pollen supplementation experiments over 2 years, we quantified the extent of pollen limitation in both habitats, testing the prediction of greater limitation in small hedgerow populations than in forests. While pollen limitation of fruit and seed set was common, its magnitude did not differ between habitats. Variations among sites, however, suggested an influence of landscape context on pollination services. Second, we examined the effect of isolation on plant reproduction by monitoring fruit and seed production, as well as pollinator activity and assemblage, in small flower arrays transplanted in hedgerows at increasing distances from forest and from each other. We detected no difference in the proportion of flowers setting fruit or in pollinator activity with isolation, but we observed some differences in pollinator assemblages. Seed set, on the other hand, declined significantly with increasing isolation in the second year of the study, but not in the first year, suggesting altered pollen transfer with distance. Overall, plants in hedgerow corridors and forests benefited from similar pollination services. In this system, plant-pollinator interactions and reproduction seem to be influenced more by variations in resource distribution over years and landscapes than by local habitat conditions.

A Continental-scale River Corridor Model to Synthesize Understanding and Prioritize Management of Water Purification Functions and Ecological Services in Large Basins

Science.gov (United States)

Harvey, J. W.; Gomez-Velez, J. D.; Scott, D.; Boyer, E. W.; Schmadel, N. M.; Alexander, R. B.; Eng, K.; Golden, H. E.; Kettner, A.; Konrad, C. P.; Moore, R. B.; Pizzuto, J. E.; Schwarz, G. E.; Soulsby, C.

2017-12-01

The functional values of rivers depend on more than just wetted river channels. Instead, the river channel exchanges water and suspended materials with adjacent riparian, floodplain, hyporheic zones, and ponded waters such as lakes and reservoirs. Together these features comprise a larger functional unit known as the river corridor. The exchange of water, solutes, and sediments within the river corridor alters downstream water quality and ecological functions, but our understanding of the large-scale, cumulative impacts is inadequate and has limited advancements in sustainable management practices. A problem with traditional watershed, groundwater, and river water quality models is that none of them explicitly accounts for river corridor storage and processing, and the exchanges of water, solutes, and sediments that occur many times between the channel and off-channel environments during a river's transport to the sea. Our River Corridor Working Group at the John Wesley Powell Center is quantifying the key components of river corridor functions. Relying on foundational studies that identified floodplain, riparian, and hyporheic exchange flows and resulting enhancement of chemical reactions at river reach scales, we are assembling the datasets and building the models to upscale that understanding onto 2.6 million river reaches in the U.S. A principal goal of the River Corridor Working group is to develop a national-scale river corridor model for the conterminous U.S. that will reveal, perhaps for the first time, the relative influences of hyporheic, riparian, floodplain, and ponded waters at large spatial scales. The simple but physically-based models are predictive for changing conditions and therefore can directly address the consequences and effectiveness of management actions in sustaining valuable river corridor functions. This presentation features interpretation of useful river corridor connectivity metrics and ponded water influences on nutrient and sediment

Observation of spatial quantum correlations induced by multiple scattering of nonclassical light

DEFF Research Database (Denmark)

Smolka, Stephan; Huck, Alexander; Andersen, Ulrik Lund

2009-01-01

and negative spatial quantum correlations are observed when varying the quantum state incident to the multiple scattering medium, and the strength of the correlations is controlled by the number of photons. The experimental results are in excellent agreement with recent theoretical proposals by implementing......We present the experimental realization of spatial quantum correlations of photons that are induced by multiple scattering of squeezed light. The quantum correlation relates photons propagating along two different light paths through the random medium and is infinite in range. Both positive...... the full quantum model of multiple scattering....

Spatial correlation analysis of urban traffic state under a perspective of community detection

Science.gov (United States)

Yang, Yanfang; Cao, Jiandong; Qin, Yong; Jia, Limin; Dong, Honghui; Zhang, Aomuhan

2018-05-01

Understanding the spatial correlation of urban traffic state is essential for identifying the evolution patterns of urban traffic state. However, the distribution of traffic state always has characteristics of large spatial span and heterogeneity. This paper adapts the concept of community detection to the correlation network of urban traffic state and proposes a new perspective to identify the spatial correlation patterns of traffic state. In the proposed urban traffic network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding correlation of traffic state. Further, the process of community detection in the urban traffic network (named GWPA-K-means) is applied to analyze the spatial dependency of traffic state. The proposed method extends the traditional K-means algorithm in two steps: (i) redefines the initial cluster centers by two properties of nodes (the GWPA value and the minimum shortest path length); (ii) utilizes the weight signal propagation process to transfer the topological information of the urban traffic network into a node similarity matrix. Finally, numerical experiments are conducted on a simple network and a real urban road network in Beijing. The results show that GWPA-K-means algorithm is valid in spatial correlation analysis of traffic state. The network science and community structure analysis perform well in describing the spatial heterogeneity of traffic state on a large spatial scale.

Freight corridor performance measurement system: A framework for South Africa

Directory of Open Access Journals (Sweden)

Jan H. Havenga

2016-11-01

Full Text Available Background: On a national level, South Africa’s freight logistics industry is inefficient. The country ranks 36th out of 40 countries in terms of transport productivity (tonne kilometres as a ratio of gross domestic product, or GDP; the ratio of freight logistics costs to GDP measured 11.1% in 2013, compared to that of developed regions which measures in the order of 9%; and rail tonne-km market share on the two most dense long-distance corridors, namely, GautengDurban and Gauteng-Cape Town, is only 12.8% and 4.4%, respectively, whereas rail is globally acknowledged as a more efficient provider of long-distance freight solutions, given appropriate investments and service commitments. Objectives: A cornerstone of improved national freight logistics performance is the availability of reliable indicators to quantify the efficiency and capacity of the logistics network over the intermediate and long term, thereby enabling an evidence-based policy and investment environment. The objective of this article is to describe the foundation framework (i.e. phase 1 for South Africa’s freight corridor performance measurement system (CPMS. Once populated, the CPMS will be a key generator of indicators to facilitate the systemic management of corridors as a national production factor and thereby contributing to South Africa’s competitiveness. Method: The design of South Africa’s CPMS was informed by desktop research and refined through an extensive stakeholder consultation process. A distinction was made between South Africa’s dedicated bulk corridors and the multi-modal corridors. Results: Facilitating both stakeholder involvement and agreement on key indicators, as well as the eventual development of a system supporting the population, aggregation and dissemination of the CPMS are critical outcomes for the management of corridors as a national production factor. Three overarching corridor indicators were defined, relating to increased throughput

HANFORD SITE RIVER CORRIDOR CLEANUP

International Nuclear Information System (INIS)

BAZZELL, K.D.

2006-01-01

In 2005, the US Department of Energy (DOE) launched the third generation of closure contracts, including the River Corridor Closure (RCC) Contract at Hanford. Over the past decade, significant progress has been made on cleaning up the river shore that bordes Hanford. However, the most important cleanup challenges lie ahead. In March 2005, DOE awarded the Hanford River Corridor Closure Contract to Washington Closure Hanford (WCH), a limited liability company owned by Washington Group International, Bechtel National and CH2M HILL. It is a single-purpose company whose goal is to safely and efficiently accelerate cleanup in the 544 km 2 Hanford river corridor and reduce or eliminate future obligations to DOE for maintaining long-term stewardship over the site. The RCC Contract is a cost-plus-incentive-fee closure contract, which incentivizes the contractor to reduce cost and accelerate the schedule. At $1.9 billion and seven years, WCH has accelerated cleaning up Hanford's river corridor significantly compared to the $3.2 billion and 10 years originally estimated by the US Army Corps of Engineers. Predictable funding is one of the key features of the new contract, with funding set by contract at $183 million in fiscal year (FY) 2006 and peaking at $387 million in FY2012. Another feature of the contract allows for Washington Closure to perform up to 40% of the value of the contract and subcontract the balance. One of the major challenges in the next few years will be to identify and qualify sufficient subcontractors to meet the goal

Energy Futures Synthesis for West-Wide Section 368 Energy Corridors

Energy Technology Data Exchange (ETDEWEB)

O' Neill, Barbara L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gagne, Douglas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cook, Jeffrey J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Greco, Tessa M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-05-01

To comply with Section 368(a) of the Energy Policy Act of 2005 (EPAct), the U.S. Bureau of Land Management (BLM) and the U.S. Forest Service designated 6,000 miles of energy corridors on public and national forest lands in the western United States in 2009. The corridors, commonly referred to as 'West-wide' or 'Section 368' energy corridors, are intended as preferred locations for future siting of electric transmission and distribution lines and for oil, gas, and hydrogen pipelines. In response to a lawsuit filed by several organizations over the corridor designations, the BLM, Forest Service, and the U.S. Department of Energy entered into a Settlement Agreement, directing the formation of the Section 368 Interagency Workgroup to periodically review the energy corridors on a regional basis. In conducting the reviews, the Workgroup identifies new, relevant, existing, publicly available information to make recommendations for revisions, deletions, and additions to the Section 368 energy corridors. This report synthesizes information in available contemporary transmission, pipeline, and energy future studies to inform the regional reviews by providing a snapshot of what the western energy and transmission system will look like generally 10-15 years in the future. After an overview of the western grid implications, the analysis narrows to Region 2 and Region 3 of the BLM Section 368 energy corridors and focuses on the implications of potential developments in the oil, natural gas, and electricity markets in Colorado, New Mexico, Utah, and portions of Arizona and Nevada that could inform the current regional review. This analysis will help inform the Workgroup on potential development within existing corridors and the need for new corridors that have not yet been designated.

Revealing Spatial Variation and Correlation of Urban Travels from Big Trajectory Data

Science.gov (United States)

Li, X.; Tu, W.; Shen, S.; Yue, Y.; Luo, N.; Li, Q.

2017-09-01

With the development of information and communication technology, spatial-temporal data that contain rich human mobility information are growing rapidly. However, the consistency of multi-mode human travel behind multi-source spatial-temporal data is not clear. To this aim, we utilized a week of taxies' and buses' GPS trajectory data and smart card data in Shenzhen, China to extract city-wide travel information of taxi, bus and metro and tested the correlation of multi-mode travel characteristics. Both the global correlation and local correlation of typical travel indicator were examined. The results show that: (1) Significant differences exist in of urban multi-mode travels. The correlation between bus travels and taxi travels, metro travel and taxi travels are globally low but locally high. (2) There are spatial differences of the correlation relationship between bus, metro and taxi travel. These findings help us understanding urban travels deeply therefore facilitate both the transport policy making and human-space interaction research.

REVEALING SPATIAL VARIATION AND CORRELATION OF URBAN TRAVELS FROM BIG TRAJECTORY DATA

Directory of Open Access Journals (Sweden)

X. Li

2017-09-01

Full Text Available With the development of information and communication technology, spatial-temporal data that contain rich human mobility information are growing rapidly. However, the consistency of multi-mode human travel behind multi-source spatial-temporal data is not clear. To this aim, we utilized a week of taxies’ and buses’ GPS trajectory data and smart card data in Shenzhen, China to extract city-wide travel information of taxi, bus and metro and tested the correlation of multi-mode travel characteristics. Both the global correlation and local correlation of typical travel indicator were examined. The results show that: (1 Significant differences exist in of urban multi-mode travels. The correlation between bus travels and taxi travels, metro travel and taxi travels are globally low but locally high. (2 There are spatial differences of the correlation relationship between bus, metro and taxi travel. These findings help us understanding urban travels deeply therefore facilitate both the transport policy making and human-space interaction research.

Planning of transport corridors by use of GIS

DEFF Research Database (Denmark)

Kronbak, Jacob; Moshøj, Claus Rehfeld; Grevy, Bo

1998-01-01

The paper adresses principles for the application of geographical information systems (GIS) as a tool in the planning of transport corridors. Specifically, the paper describes the COPE (corridor planning and evaluation) model that has been developed within the EU 4th FP Strategic Transport projects...

Spatial and temporal correlation in dynamic, multi-electron quantum systems

Energy Technology Data Exchange (ETDEWEB)

Godunov, A.L.; McGuire, J.H.; Shakov, Kh.Kh. [Department of Physics, Tulane University, New Orleans, LA (United States); Ivanov, P.B.; Shipakov, V.A. [Troitsk Institute for Innovation and Fusion Research, Troitsk (Russian Federation); Merabet, H.; Bruch, R.; Hanni, J. [Department of Physics, University of Nevada Reno, Reno, NV (United States)

2001-12-28

Cross sections for ionization with excitation and for double excitation in helium are evaluated in a full second Born calculation. These full second Born calculations are compared to calculations in the independent electron approximation, where spatial correlation between the electrons is removed. Comparison is also made to calculations in the independent time approximation, where time correlation between the electrons is removed. The two-electron transitions considered here are caused by interactions with incident protons and electrons with velocities ranging between 2 and 10 au. Good agreement is found between our full calculations and experiment, except for the lowest velocities, where higher Born terms are expected to be significant. Spatial electron correlation, arising from internal electron-electron interactions, and time correlation, arising from time ordering of the external interactions, can both give rise to observable effects. Our method may be used for photon impact. (author)

Designing Conservation Corridors in Production Landscapes: Assessment Methods, Implementation Issues, and Lessons Learned

Directory of Open Access Journals (Sweden)

Amanda T. Lombard

2010-09-01

Full Text Available Designing broad-scale conservation corridors has become increasingly common as a way of conducting an assessment for achieving targets for the representation and persistence of nature. However, since many of these corridors must traverse agricultural and other production landscapes, planning and implementation are not trivial tasks. Most approaches to conservation assessments in the dynamic world of production landscapes are data-intensive and analytically complex. However, in the real world, donor and other external requirements impose time and budget constraints, and dictate strong stakeholder involvement in the entire planning process. In order to accommodate this, assessments must be rapid, cheap, and the approach and products must be comprehensible and acceptable to stakeholders. Here we describe such an assessment aimed at identifying and implementing a network of conservation corridors in the Gouritz Initiative project domain of South Africa's Cape Floristic Region hotspot. We used empirical data and expert knowledge to identify a corridor network hypothesized to sustain key ecological and evolutionary processes. We also consulted experts to provide a spatially explicit assessment of the opportunity costs of conservation associated with agriculture, the predominant land use in the region. We used these products to identify categories of land requiring different actions and instruments to achieve conservation goals, thereby moving from the "where" to the "how" of conservation. This information was then fed into the collaborative strategy development process for the Gouritz Initiative. Our discussion emphasizes the lessons that we learnt from undertaking this assessment, particularly lessons regarding the implementation of the planning products. We conclude that at the outset of any planning project, a consensus on the vision must be achieved, a detailed social assessment of appropriate institutions must be undertaken, and a learning

Visual quality evaluation of urban commercial streetscape for the development of landscape visual planning system in provincial street corridors in Malang, Indonesia

Science.gov (United States)

Santosa, H.; Ernawati, J.; Wulandari, L. D.

2018-03-01

The visual aesthetic experience in urban spaces is important in establishing a comfortable and satisfying experience for the community. The embodiment of a good visual image of urban space will encourage the emergence of positive perceptions and meanings stimulating the community to produce a good reaction to its urban space. Moreover, to establish a Good Governance in urban planning and design, it is necessary to boost and promote a community participation in the process of controlling the visual quality of urban space through the visual quality evaluation on urban street corridors. This study is an early stage as part of the development of ‘Landscape Visual Planning System’ on the commercial street corridor in Malang. Accordingly, the research aims to evaluate the physical characteristics and the public preferences of the spatial and visual aspects in five provincial road corridors in Malang. This study employs a field survey methods, and an environmental aesthetics approach through semantic differential method. The result of the identification of physical characteristics and the assessment of public preferences on the spatial and visual aspects of the five provincial streets serve as the basis for constructing the 3d interactive simulation scenarios in the Landscape Visual Planning System.

Effects of vegetation, corridor width and regional land use on early successional birds on powerline corridors.

Directory of Open Access Journals (Sweden)

Robert A Askins

Full Text Available Powerline rights-of-way (ROWs often provide habitat for early successional bird species that have suffered long-term population declines in eastern North America. To determine how the abundance of shrubland birds varies with habitat within ROW corridors and with land use patterns surrounding corridors, we ran Poisson regression models on data from 93 plots on ROWs and compared regression coefficients. We also determined nest success rates on a 1-km stretch of ROW. Seven species of shrubland birds were common in powerline corridors. However, the nest success rates for prairie warbler (Dendroica discolor and field sparrow (Spizella pusilla were <21%, which is too low to compensate for estimated annual mortality. Some shrubland bird species were more abundant on narrower ROWs or at sites with lower vegetation or particular types of vegetation, indicating that vegetation management could be refined to favor species of high conservation priority. Also, several species were more abundant in ROWs traversing unfragmented forest than those near residential areas or farmland, indicating that corridors in heavily forested regions may provide better habitat for these species. In the area where we monitored nests, brood parasitism by brown-headed cowbirds (Molothrus ater occurred more frequently close to a residential area. Although ROWs support dense populations of shrubland birds, those in more heavily developed landscapes may constitute sink habitat. ROWs in extensive forests may contribute more to sustaining populations of early successional birds, and thus may be the best targets for habitat management.

Comprehensive highway corridor planning with sustainability indicators : [research summary].

Science.gov (United States)

2013-04-01

The Maryland State Highway Administration (SHA) has initiated major planning : efforts to improve transportation efficiency, safety and sustainability on critical : highway corridors through its Comprehensive Highway Corridor (CHC) program. : It is i...

Variable input parameter influence on river corridor prediction

NARCIS (Netherlands)

Zerfu, T.; Beevers, L.; Crosato, A.; Wright, N.

2015-01-01

This paper considers the erodible river corridor, which is the area in which the main river channel is free to migrate over a period of time. Due to growing anthropogenic pressure, predicting the corridor width has become increasingly important for the planning of development along rivers. Several

Quantifying geomorphic controls on riparian forest dynamics using a linked physical-biological model: implications for river corridor conservation

Science.gov (United States)

Stella, J. C.; Harper, E. B.; Fremier, A. K.; Hayden, M. K.; Battles, J. J.

2009-12-01

In high-order alluvial river systems, physical factors of flooding and channel migration are particularly important drivers of riparian forest dynamics because they regulate habitat creation, resource fluxes of water, nutrients and light that are critical for growth, and mortality from fluvial disturbance. Predicting vegetation composition and dynamics at individual sites in this setting is challenging, both because of the stochastic nature of the flood regime and the spatial variability of flood events. Ecological models that correlate environmental factors with species’ occurrence and abundance (e.g., ’niche models’) often work well in infrequently-disturbed upland habitats, but are less useful in river corridors and other dynamic zones where environmental conditions fluctuate greatly and selection pressures on disturbance-adapted organisms are complex. In an effort to help conserve critical riparian forest habitat along the middle Sacramento River, CA, we are taking a mechanistic approach to quantify linkages between fluvial and biotic processes for Fremont cottonwood (Populus fremontii), a keystone pioneer tree in dryland rivers ecosystems of the U.S. Southwest. To predict the corridor-wide population effects of projected changes to the disturbance regime from flow regulation, climate change, and landscape modifications, we have coupled a physical model of channel meandering with a patch-based population model that incorporates the climatic, hydrologic, and topographic factors critical for tree recruitment and survival. We employed these linked simulations to study the relative influence of the two most critical habitat types--point bars and abandoned channels--in sustaining the corridor-wide cottonwood population over a 175-year period. The physical model uses discharge data and channel planform to predict the spatial distribution of new habitat patches; the population model runs on top of this physical template to track tree colonization and survival on

Training plan : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2013-01-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

Test report : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2015-05-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) : Demonstration Project for the Dallas region. Coordinated corridor operations and management is : predicated on being able to share transportation informa...

Final report : Dallas Integrated Corridor Management (ICM) Demonstration Project.

Science.gov (United States)

2015-08-01

The Dallas Area Rapid Transit (DART) is leading the US-75 Integrated Corridor Management (ICM) Demonstration Project for the Dallas region. Coordinated corridor operations and management is predicated on being able to share transportation information...

Final report: Prototyping a combustion corridor; FINAL

International Nuclear Information System (INIS)

Rutland, Christopher J.; Leach, Joshua

2001-01-01

The Combustion Corridor is a concept in which researchers in combustion and thermal sciences have unimpeded access to large volumes of remote computational results. This will enable remote, collaborative analysis and visualization of state-of-the-art combustion science results. The Engine Research Center (ERC) at the University of Wisconsin - Madison partnered with Lawrence Berkeley National Laboratory, Argonne National Laboratory, Sandia National Laboratory, and several other universities to build and test the first stages of a combustion corridor. The ERC served two important functions in this partnership. First, we work extensively with combustion simulations so we were able to provide real world research data sets for testing the Corridor concepts. Second, the ERC was part of an extension of the high bandwidth based DOE National Laboratory connections to universities

Perceptions of brachyfacial, mesofacial and dolichofacial individuals with regard to the buccal corridor in different facial types

Directory of Open Access Journals (Sweden)

Matheus Melo PITHON

2014-10-01

Full Text Available Objective: Evaluate the esthetic perception and attractiveness of the smile with regard to the buccal corridor in different facial types by brachyfacial, mesofacial and dolichofacial individuals. Material and Methods: The image of a smiling individual with a mesofacial type of face was changed to create three different facial types with five different buccal corridors (2%, 10%, 15%, 22% and 28%. To achieve this effect, a photo editing software was used (Adobe Photoshop, Adobe Systems Inc, San Francisco, CA, EUA. The images were submitted to evaluators with brachyfacial, mesofacial and dolichofacial types of faces, who evaluated the degree of esthetic perception and attractiveness by means of a visual analog scale measuring 70 mm. The differences between evaluators were verified by the Mann-Whitney test. All statistics were performed with a confidence level of 95%. Results: Brachyfacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2% as more attractive. Mesofacial individuals perceived mesofacial and dolichofacial types of faces with buccal corridor of 2%, 10% and 15% as more attractive. Dolichofacial individuals perceived the mesofacial type of face with buccal corridor of 2% as more attractive. Evaluators of the female sex generally attributed higher scores than the male evaluators. Conclusion: To achieve an enhanced esthetic smile it is necessary to observe the patient’s facial type. The preference for narrow buccal corridors is an esthetic characteristic preferred by men and women, and wide buccal corridors are less attractive.

SPATIAL CORRELATION BETWEEN PHYSICAL PROPERTIES OF SOIL AND WEEDS IN TWO MANAGEMENT SYSTEMS

Directory of Open Access Journals (Sweden)

Valter Roberto Schaffrath

2015-02-01

Full Text Available The spatial correlation between soil properties and weeds is relevant in agronomic and environmental terms. The analysis of this correlation is crucial for the interpretation of its meaning, for influencing factors such as dispersal mechanisms, seed production and survival, and the range of influence of soil management techniques. This study aimed to evaluate the spatial correlation between the physical properties of soil and weeds in no-tillage (NT and conventional tillage (CT systems. The following physical properties of soil and weeds were analyzed: soil bulk density, macroporosity, microporosity, total porosity, aeration capacity of soil matrix, soil water content at field capacity, weed shoot biomass, weed density, Commelina benghalensis density, and Bidens pilosa density. Generally, the ranges of the spatial correlations were higher in NT than in CT. The cross-variograms showed that many variables have a structure of combined spatial variation and can therefore be mapped from one another by co-kriging. This combined variation also allows inferences about the physical and biological meanings of the study variables. Results also showed that soil management systems influence the spatial dependence structure significantly.

Bipole III transmission line Henday-Riel: Alternative corridors status report

International Nuclear Information System (INIS)

1991-01-01

As part of expansion plans in the Manitoba Hydro system, it is proposed to build a 850-km high voltage dc transmission line from the Henday converter station on the Nelson River to a new converter station near Winnipeg. A review is provided of work done on the first stage of route selection and environmental assessment for this project. Right-of-way requirements are outlined and environmental impact issues are discussed in the areas of employment and business opportunities, effects on wilderness areas and aesthetics, electric and magnetic field effects, and land use. The four zones, east and west of Lake Winnipeg, that were studied in the selection of potential corridors are described along with the corridor siting criteria. Five discrete corridor alternatives are identified and evaluated. A route east of Lake Winnipeg has been selected as the preferred corridor. Feedback from public consultations will assist in preparation of a final corridor selection study which is to be submitted to federal and provincial environmental review. 12 figs

78 FR 7477 - Multistate Corridor Operations and Management Program

Science.gov (United States)

2013-02-01

... in the Multistate Corridor Operations and Management Program authorized by the Safe, Accountable... projects to improve multimodal transportation system management and operations. This notice seeks... Multistate Corridor Operations and Management (MCOM) programs and projects. The purpose of these investments...

The “Humanitarian” Corridor: A state of exception in times of global migration

Directory of Open Access Journals (Sweden)

Neža Kogovšek Šalamon

2016-06-01

Full Text Available The purpose of the article is to analyse the migration corridor managed by the state authorities on the Balkan migration route in the second half of 2015, understand it from the perspective of the existing legal and institutional frameworks, and show that the corridor was a phenomenon outside of national and European positive law, while at the same time it responded to the requirements of international human rights principles. The corridor was a clear, intentional and coordinated deviation from legal provisions. It amounted to a state of exception, a certain level of state of emergency in which the rules adopted by the national and European legislatures were suspended and replaced by internal instructions or decrees, or even with constantly changing state practices. The analysis involved comparison of a positive normative framework with the actual procedures carried out by the state structures, and identification of discrepancies which were then qualitatively evaluated from the perspective of international standards. Another purpose of the article was to show that the corridor which was also sometimes referred to as a “humanitarian corridor”, only seemed humanitarian since in fact it served a completely different purpose, namely the interests of state authorities for the refugees and migrants to leave their territories as quickly as possible.

Multilevel discretized random field models with 'spin' correlations for the simulation of environmental spatial data

Science.gov (United States)

Žukovič, Milan; Hristopulos, Dionissios T.

2009-02-01

A current problem of practical significance is how to analyze large, spatially distributed, environmental data sets. The problem is more challenging for variables that follow non-Gaussian distributions. We show by means of numerical simulations that the spatial correlations between variables can be captured by interactions between 'spins'. The spins represent multilevel discretizations of environmental variables with respect to a number of pre-defined thresholds. The spatial dependence between the 'spins' is imposed by means of short-range interactions. We present two approaches, inspired by the Ising and Potts models, that generate conditional simulations of spatially distributed variables from samples with missing data. Currently, the sampling and simulation points are assumed to be at the nodes of a regular grid. The conditional simulations of the 'spin system' are forced to respect locally the sample values and the system statistics globally. The second constraint is enforced by minimizing a cost function representing the deviation between normalized correlation energies of the simulated and the sample distributions. In the approach based on the Nc-state Potts model, each point is assigned to one of Nc classes. The interactions involve all the points simultaneously. In the Ising model approach, a sequential simulation scheme is used: the discretization at each simulation level is binomial (i.e., ± 1). Information propagates from lower to higher levels as the simulation proceeds. We compare the two approaches in terms of their ability to reproduce the target statistics (e.g., the histogram and the variogram of the sample distribution), to predict data at unsampled locations, as well as in terms of their computational complexity. The comparison is based on a non-Gaussian data set (derived from a digital elevation model of the Walker Lake area, Nevada, USA). We discuss the impact of relevant simulation parameters, such as the domain size, the number of

Migratory corridors of adult female Kemp’s ridley turtles in the Gulf of Mexico

Science.gov (United States)

Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain-Iverson, Autumn R.; Pena, Jaime; Gamez, Daniel Gomez; Gonzales Diaz Miron, Raul de Jesus; Burchfield, Patrick M.; Martinez, Hector J.; Ortiz, Jaime

2016-01-01

For many marine species, locations of migratory pathways are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to define the migratory corridor used by Kemp's ridley turtles (Lepidochelys kempii) in the Gulf of Mexico. The turtles were tagged after nesting at Padre Island National Seashore, Texas, USA from 1997 to 2014 (PAIS; n = 80); Rancho Nuevo, Tamaulipas, Mexico from 2010 to 2011 (RN; n = 14); Tecolutla, Veracruz, Mexico from 2012 to 2013 (VC; n = 13); and Gulf Shores, Alabama, USA during 2012 (GS; n = 1). The migratory corridor lies in nearshore Gulf of Mexico waters in the USA and Mexico with mean water depth of 26 m and a mean distance of 20 km from the nearest mainland coast. Migration from the nesting beach is a short phenomenon that occurs from late-May through August, with a peak in June. There was spatial similarity of post-nesting migratory pathways for different turtles over a 16 year period. Thus, our results indicate that these nearshore Gulf waters represent a critical migratory habitat for this species. However, there is a gap in our understanding of the migratory pathways used by this and other species to return from foraging grounds to nesting beaches. Therefore, our results highlight the need for tracking reproductive individuals from foraging grounds to nesting beaches. Continued tracking of adult females from PAIS, RN, and VC nesting beaches will allow further study of environmental and bathymetric components of migratory habitat and threats occurring within our defined corridor. Furthermore, the existence of this migratory corridor in nearshore waters of both the USA and Mexico demonstrates that international cooperation is necessary to protect essential migratory habitat for this imperiled species.

CORRIDOR-TYPE BAFFLED MIXING BASIN WITH CROSS POROUS BARRIERS

Directory of Open Access Journals (Sweden)

S. M. Epoyan

2018-02-01

Full Text Available Purpose. The paper hightlights the increase in operational efficiency of corridor-type baffled mixing basin by installing of cross porous barriers made of gravel (or other materials and epoxy resin, grade ED-20 (ED-16 with the hardener polyethylenepolyamine (PEPA, approved by Ukrainian Ministry of Health in systems of utility and drinking water supply. Methodology. The first stage of the experiments was performed on the model of the proposed mixer in scale 1:4 in order to determine the local resistance of the porous barrier, which is made of gravel with a size of 10-15 mm (average diameter 12.5 mm and thickness of 50 mm. The local resistance of the barrier was measured using piezometers installed before and after the porous barrier. The velocity of water motion in the corridor of the mixer was determined depending on the water consumption, incoming on the mixer accordingly to the water meter and by the volumetric method. Findings. In accordance with researches when the water flows at a velocity of 0.1 m/s in the corridor of the mixer, the head losses in the porous barrier is 17 cm (0.17 m, and at a velocity of 0.2 m/s–0.68 m. The resistance coefficient (ξ, which is equal to 333.2 for the investigated barrier, was determined experimentally. It allows determining the head losses in the porous barrier at other velocities of water motion. When the velocity of water motion in the corridors of the mixer is from 0.7 up to 0.5 m/s, head losses increase almost fourfold. The conducted researches allowed to develop a calculation methodology for corridor-type baffled mixing basin with porous polymer-concrete barriers. Originality. Authors developed and investigated the corridor-type baffled mixing basin with porous polymer-concrete barriers. These barriers allow increasing and regulating the intensity and time of reagents mixing with the initial water exactly in the barriers, improving the distribution of the flow through the section of the mixer

78 FR 23815 - Northeast Corridor Safety Committee; Notice of Meeting

Science.gov (United States)

2013-04-22

.... 6] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of the Northeast Corridor Safety Committee (NECSC) Meeting. [[Page 23816

Spatially correlated disorder in striped precursor magnetic modulations

International Nuclear Information System (INIS)

Porta, Marcel; Castan, Teresa; LLoveras, Pol; Planes, Antoni; Saxena, Avadh

2007-01-01

We use a Ginzburg-Landau model that includes long-range dipolar interactions and spatially correlated quenched-in disorder coupled to the local magnetization to study the properties of the precursor magnetic modulations as a function of the characteristics of the disorder. We find that although the modulation pattern is very robust and does not depend on details of the pair correlation function G(r), the scaling behaviour of the characteristic length of the striped magnetic modulations depends on the behaviour of G(r) for small values of r

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

Science.gov (United States)

Gay-Balmaz, François; Holm, Darryl D.

2018-01-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

Science.gov (United States)

Gay-Balmaz, François; Holm, Darryl D.

2018-06-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

River networks as ecological corridors: A coherent ecohydrological perspective

Science.gov (United States)

Rinaldo, Andrea; Gatto, Marino; Rodriguez-Iturbe, Ignacio

2018-02-01

This paper draws together several lines of argument to suggest that an ecohydrological framework, i.e. laboratory, field and theoretical approaches focused on hydrologic controls on biota, has contributed substantially to our understanding of the function of river networks as ecological corridors. Such function proves relevant to: the spatial ecology of species; population dynamics and biological invasions; the spread of waterborne disease. As examples, we describe metacommunity predictions of fish diversity patterns in the Mississippi-Missouri basin, geomorphic controls imposed by the fluvial landscape on elevational gradients of species' richness, the zebra mussel invasion of the same Mississippi-Missouri river system, and the spread of proliferative kidney disease in salmonid fish. We conclude that spatial descriptions of ecological processes in the fluvial landscape, constrained by their specific hydrologic and ecological dynamics and by the ecosystem matrix for interactions, i.e. the directional dispersal embedded in fluvial and host/pathogen mobility networks, have already produced a remarkably broad range of significant results. Notable scientific and practical perspectives are thus open, in the authors' view, to future developments in ecohydrologic research.

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William; Genton, Marc G.

2012-01-01

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Spatially varying cross-correlation coefficients in the presence of nugget effects

KAUST Repository

Kleiber, William

2012-11-29

We derive sufficient conditions for the cross-correlation coefficient of a multivariate spatial process to vary with location when the spatial model is augmented with nugget effects. The derived class is valid for any choice of covariance functions, and yields substantial flexibility between multiple processes. The key is to identify the cross-correlation coefficient matrix with a contraction matrix, which can be either diagonal, implying a parsimonious formulation, or a fully general contraction matrix, yielding greater flexibility but added model complexity. We illustrate the approach with a bivariate minimum and maximum temperature dataset in Colorado, allowing the two variables to be positively correlated at low elevations and nearly independent at high elevations, while still yielding a positive definite covariance matrix. © 2012 Biometrika Trust.

Horizontal Residual Mean Circulation: Evaluation of Spatial Correlations in Coarse Resolution Ocean Models

Science.gov (United States)

Li, Y.; McDougall, T. J.

2016-02-01

Coarse resolution ocean models lack knowledge of spatial correlations between variables on scales smaller than the grid scale. Some researchers have shown that these spatial correlations play a role in the poleward heat flux. In order to evaluate the poleward transport induced by the spatial correlations at a fixed horizontal position, an equation is obtained to calculate the approximate transport from velocity gradients. The equation involves two terms that can be added to the quasi-Stokes streamfunction (based on temporal correlations) to incorporate the contribution of spatial correlations. Moreover, these new terms do not need to be parameterized and is ready to be evaluated by using model data directly. In this study, data from a high resolution ocean model have been used to estimate the accuracy of this HRM approach for improving the horizontal property fluxes in coarse-resolution ocean models. A coarse grid is formed by sub-sampling and box-car averaging the fine grid scale. The transport calculated on the coarse grid is then compared to the transport on original high resolution grid scale accumulated over a corresponding number of grid boxes. The preliminary results have shown that the estimate on coarse resolution grids roughly match the corresponding transports on high resolution grids.

A preliminary assessment of the effectiveness of the Mesoamerican Biological Corridor for protecting potential Baird's tapir (Tapirus bairdii) habitat in Southern Mexico.

Science.gov (United States)

Mendoza, Eduardo; Fuller, Trevon L; Thomassen, Henri A; Buermann, Wolfgang; Ramírez-Mejía, Diana; Smith, Thomas B

2013-03-01

Baird's tapir (Tapirus bairdii) is one of the most emblematic mammals of Mesoamerica, but like other large-bodied animals, it is facing an increasing risk of extinction due primarily to habitat loss. Mexico's 'ortion of the Mesoamerican Biological Corridor (MBC-M) is located in one of the main strongholds for Bairds tapir. To assess the MBC-M's effectiveness for tapir conservation, we estimated the distribution of the species' potential habitat by applying 2 modelling approaches (random forest and Maxent) to a set of uncorrelated environmental variables and a 157-point presence dataset. We calculated the extent of tapir habitat in within the MBC-M and modelled new corridors and conservation areas, which we compared to the MBC-M. Moreover, we assessed deforestation patterns in the region. Twenty-seven percent of highly suitable tapir habitat occurred in protected areas, 15% in corridors and 58.3% was outside the MBC-M and associated reserves. The spatial configuration of the MBC-M was partially concordant with the modelled set of conservation areas and corridors. The main dissimilarity was that the modelled corridors traversed forests in Belize and Guatemala to connect conservation areas. Analyses of deforestation since 1993 and human population density in the vicinity of the MBC-M indicated that future conservation efforts should give particular attention to the Montes Azules-El Triunfo Corridor due to greater habitat threat. The MBC-M has a great potential to play a prominent role in the conservation of tapir habitat but there is an urgent need to implement management plans that reinforce and complement this conservation initiative. © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Wood and Sediment Dynamics in River Corridors

Science.gov (United States)

Wohl, E.; Scott, D.

2015-12-01

Large wood along rivers influences entrainment, transport, and storage of mineral sediment and particulate organic matter. We review how wood alters sediment dynamics and explore patterns among volumes of instream wood, sediment storage, and residual pools for dispersed pieces of wood, logjams, and beaver dams. We hypothesized that: volume of sediment per unit area of channel stored in association with wood is inversely proportional to drainage area; the form of sediment storage changes downstream; sediment storage correlates most strongly with wood load; and volume of sediment stored behind beaver dams correlates with pond area. Lack of data from larger drainage areas limits tests of these hypotheses, but analyses suggest a negative correlation between sediment volume and drainage area and a positive correlation between wood and sediment volume. The form of sediment storage in relation to wood changes downstream, with wedges of sediment upstream from jammed steps most prevalent in small, steep channels and more dispersed sediment storage in lower gradient channels. Use of a published relation between sediment volume, channel width, and gradient predicted about half of the variation in sediment stored upstream from jammed steps. Sediment volume correlates well with beaver pond area. Historically more abundant instream wood and beaver populations likely equated to greater sediment storage within river corridors. This review of the existing literature on wood and sediment dynamics highlights the lack of studies on larger rivers.

77 FR 73734 - Northeast Corridor Safety Committee; Notice of Meeting

Science.gov (United States)

2012-12-11

.... 5] Northeast Corridor Safety Committee; Notice of Meeting AGENCY: Federal Railroad Administration (FRA), Department of Transportation (DOT). ACTION: Announcement of a Northeast Corridor Safety... Committee is made up of stakeholders operating on the [[Page 73735

Out of Africa: the importance of rivers as human migration corridors

Science.gov (United States)

Ramirez, J. A.; Coulthard, T. J.; Rogerson, M.; Barton, N.; Bruecher, T.

2013-12-01

The route and timing of Homo sapiens exiting Africa remains uncertain. Corridors leading out of Africa through the Sahara, the Nile Valley, and the Red Sea coast have been proposed as migration routes for anatomically modern humans 80,000-130,000 years ago. During this time climate conditions in the Sahara were wetter than present day, and monsoon rainfall fed rivers that flowed across the desert landscape. The location and timing of these rivers may have supported human migration northward from central Africa to the Mediterranean coast, and onwards to Europe or Asia. Here, we use palaeoclimate rainfall and a hydrological model to spatially simulate and quantitatively test the existence of three major rivers crossing the Sahara from south to north during the time of human migration. We provide evidence that, given realistic underlying climatology, the well-known Sahabi and Kufrah rivers very likely flowed across modern day Libya and reached the coast. More unexpectedly an additional river crossed the core of the Sahara through Algeria (Irharhar river) and flowed into the Chotts basin. The Irharhar river is unique, because it links locations in central Africa experiencing monsoon climates with temperate coastal Mediterranean environments where food and resources were likely abundant. From an ecological perspective, this little-known corridor may prove to be the most parsimonious migration route. Support for the Irharar as a viable migration corridor is provided by its geographic proximity to middle Stone Age archaeological artefacts found in North Africa. Our new, highly novel approach provides the first quantitative analysis of the likelihood that rivers occurred during the critical period of human migration out of Africa. Simulated probability of surface water in North Africa during the last interglacial and the location of tools and ornaments from the Middle Stone Age.

Hierarchical clustering using correlation metric and spatial continuity constraint

Science.gov (United States)

Stork, Christopher L.; Brewer, Luke N.

2012-10-02

Large data sets are analyzed by hierarchical clustering using correlation as a similarity measure. This provides results that are superior to those obtained using a Euclidean distance similarity measure. A spatial continuity constraint may be applied in hierarchical clustering analysis of images.

A composite likelihood approach for spatially correlated survival data

Science.gov (United States)

Paik, Jane; Ying, Zhiliang

2013-01-01

The aim of this paper is to provide a composite likelihood approach to handle spatially correlated survival data using pairwise joint distributions. With e-commerce data, a recent question of interest in marketing research has been to describe spatially clustered purchasing behavior and to assess whether geographic distance is the appropriate metric to describe purchasing dependence. We present a model for the dependence structure of time-to-event data subject to spatial dependence to characterize purchasing behavior from the motivating example from e-commerce data. We assume the Farlie-Gumbel-Morgenstern (FGM) distribution and then model the dependence parameter as a function of geographic and demographic pairwise distances. For estimation of the dependence parameters, we present pairwise composite likelihood equations. We prove that the resulting estimators exhibit key properties of consistency and asymptotic normality under certain regularity conditions in the increasing-domain framework of spatial asymptotic theory. PMID:24223450

A composite likelihood approach for spatially correlated survival data.

Science.gov (United States)

Paik, Jane; Ying, Zhiliang

2013-01-01

The aim of this paper is to provide a composite likelihood approach to handle spatially correlated survival data using pairwise joint distributions. With e-commerce data, a recent question of interest in marketing research has been to describe spatially clustered purchasing behavior and to assess whether geographic distance is the appropriate metric to describe purchasing dependence. We present a model for the dependence structure of time-to-event data subject to spatial dependence to characterize purchasing behavior from the motivating example from e-commerce data. We assume the Farlie-Gumbel-Morgenstern (FGM) distribution and then model the dependence parameter as a function of geographic and demographic pairwise distances. For estimation of the dependence parameters, we present pairwise composite likelihood equations. We prove that the resulting estimators exhibit key properties of consistency and asymptotic normality under certain regularity conditions in the increasing-domain framework of spatial asymptotic theory.

Concept of operations : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2010-06-01

This concept of operations (Con Ops) for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the US : Department of Transportation Integrated Corridor Management Initiative, which is an innovative research initiative ...

Fracture corridors as seal-bypass systems in siliciclastic reservoir-cap rock successions: Field-based insights from the Jurassic Entrada Formation (SE Utah, USA)

NARCIS (Netherlands)

Ogata, Kei; Senger, Kim; Braathen, Alvar; Tveranger, Jan

2014-01-01

Closely spaced, sub-parallel fracture networks contained within localized tabular zones that are fracture corridors may compromise top seal integrity and form pathways for vertical fluid flow between reservoirs at different stratigraphic levels. This geometry is exemplified by fracture corridors

The role of climatic cycles and trans-Saharan migration corridors in species diversification: Biogeography of Psammophis schokari group in North Africa.

Science.gov (United States)

Gonçalves, Duarte Vasconcelos; Martínez-Freiría, Fernando; Crochet, Pierre-André; Geniez, Philippe; Carranza, Salvador; Brito, José Carlos

2018-01-01

Highlands, hydrographic systems and coastal areas have been hypothesised to form corridors across the hyperarid Sahara desert in North Africa, allowing dispersal and gene flow for non-xeric species. Here we aim to provide a genetic test for the trans-Saharan corridor model, and predict the location and stability of ecological-corridors, by combining phylogeography and palaeoclimatic modelling. The model was the Psammophis schokari (Schokari sand racer) group, fast-moving and widely distributed generalist colubrids occurring mostly in arid and semiarid scrublands. We combined dated phylogenies of mitochondrial and nuclear markers with palaeoclimatic modelling. For the phylogeographic analysis, we used 75 samples of P. schokari and P. aegyptius, and Bayesian and Maximum-Likelihood methods. For the ecological models, we used Maxent over the distribution of P. schokari and West African lineages. Models were projected to past conditions (mid Holocene, Last Glacial Maximum and Last Inter-Glacial) to infer climatic stable areas. Climatic stability was predicted to be mostly restricted to coastal areas and not spatially continuous. A putative temporary trans-Saharan corridor was identified in Eastern Sahara, with a more stable one along the Atlantic coast. Six parapatric lineages were identified within P. schokari, four occurring in North Africa. These likely diverged during the Pliocene. The Tamanraset River might have been a vicariant agent. African lineages may have experienced further subsequent diversification during the late Pleistocene. The main P. schokari refugia were probably located along the northern margins of the Sahara, allowing its North-to-South colonization. Trans-Saharan corridors seem to have played a role in P. schokari biogeography, allowing colonization of central Saharan mountains and Sahel. Some might have worked as refugia, and even the most stable corridors may have sections working as filters, depending on each climatic phase. We expect the use

Correlated density matrix theory of spatially inhomogeneous Bose fluids

International Nuclear Information System (INIS)

Gernoth, K.A.; Clark, J.W.; Ristig, M.L.

1994-06-01

In this paper, the variational Hartree-Jastrow theory of the ground state of spatially inhomogeneous Bose systems is extended to finite temperatures. The theory presented here is a generalization also in the sense that it extends the correlated density matrix approach, formulated previously for uniform Bose fluids, to systems with nonuniform density profiles. The method provides a framework in which the effects of thermal excitations on the spatial structure of a Bose fluid, as represented by the density profile and the two-body distribution functions, may be discussed on the basis on an ab initio microscopic description of the system. Thermal excitations make their appearance through self-consistently determined one-body and two-body potentials which enter the nonlinear, coupled Euler-Lagrange equations for the one-body density and for the pair distribution function. Since back-flow correlations are neglected, the excitations are described by a Feynman eigenvalue equation, suitably generalized to nonzero temperatures. The only external quantities entering the correlated density matrix theory elaborated here are the bare two-body interaction potential and, in actual applications, the boundary conditions to be imposed on the one-body density. 30 refs

High-speed surface transportation corridor : a conceptual framework, final report.

Science.gov (United States)

2009-10-08

Efficient transportation is indispensable for economic growth and prosperity. In this study we propose the development of a high-speed surface corridor and compatible vehicles. We present a conceptual framework for this corridor and vehicle. This pro...

Spatially heterogeneous dynamics investigated via a time-dependent four-point density correlation function

DEFF Research Database (Denmark)

Lacevic, N.; Starr, F. W.; Schrøder, Thomas

2003-01-01

correlation function g4(r,t) and corresponding "structure factor" S4(q,t) which measure the spatial correlations between the local liquid density at two points in space, each at two different times, and so are sensitive to dynamical heterogeneity. We study g4(r,t) and S4(q,t) via molecular dynamics......Relaxation in supercooled liquids above their glass transition and below the onset temperature of "slow" dynamics involves the correlated motion of neighboring particles. This correlated motion results in the appearance of spatially heterogeneous dynamics or "dynamical heterogeneity." Traditional...... two-point time-dependent density correlation functions, while providing information about the transient "caging" of particles on cooling, are unable to provide sufficiently detailed information about correlated motion and dynamical heterogeneity. Here, we study a four-point, time-dependent density...

Control Strategies for Corridor Management

Science.gov (United States)

2016-06-28

Integrated management of travel corridors comprising of freeways and adjacent arterial streets can potentially improve the performance of the highway facilities. However, several research gaps exist in data collection and performance measurement, ana...

Spatial and temporal stability of temperature in the first-level basins of China during 1951-2013

Science.gov (United States)

Cheng, Yuting; Li, Peng; Xu, Guoce; Li, Zhanbin; Cheng, Shengdong; Wang, Bin; Zhao, Binhua

2018-05-01

In recent years, global warming has attracted great attention around the world. Temperature change is not only involved in global climate change but also closely linked to economic development, the ecological environment, and agricultural production. In this study, based on temperature data recorded by 756 meteorological stations in China during 1951-2013, the spatial and temporal stability characteristics of annual temperature in China and its first-level basins were investigated using the rank correlation coefficient method, the relative difference method, rescaled range (R/S) analysis, and wavelet transforms. The results showed that during 1951-2013, the spatial variation of annual temperature belonged to moderate variability in the national level. Among the first-level basins, the largest variation coefficient was 114% in the Songhuajiang basin and the smallest variation coefficient was 10% in the Huaihe basin. During 1951-2013, the spatial distribution pattern of annual temperature presented extremely strong spatial and temporal stability characteristics in the national level. The variation range of Spearman's rank correlation coefficient was 0.97-0.99, and the spatial distribution pattern of annual temperature showed an increasing trend. In the national level, the Liaohe basin, the rivers in the southwestern region, the Haihe basin, the Yellow River basin, the Yangtze River basin, the Huaihe basin, the rivers in the southeastern region, and the Pearl River basin all had representative meteorological stations for annual temperature. In the Songhuajiang basin and the rivers in the northwestern region, there was no representative meteorological station. R/S analysis, the Mann-Kendall test, and the Morlet wavelet analysis of annual temperature showed that the best representative meteorological station could reflect the variation trend and the main periodic changes of annual temperature in the region. Therefore, strong temporal stability characteristics exist for

The Padanian LiMeS. Spatial Interpretation of Local GHG Emission Data

Directory of Open Access Journals (Sweden)

Michèle Pezzagno

2015-04-01

Full Text Available The relevant role of spatial planning in the enforcement of climate change mitigation, managing the development of new low-carbon infrastructures and increasing system-wide efficiencies across sectors, has been addressed at global level (IPCC, 2014 WGIII. In this context, local GHG inventories appear a relevant tool toward the definition of a coherent, inter-sectorial background for local planning, mitigation, and adaptation policies.Taking advantage of consistent GHG emissions data availability in the Lombard context, local maps of direct GHG emissions have been linked with geographic data, including municipal boundaries, population data, and land-use information, produced and organized within the research PRIN 2007 From metropolitan city to metropolitan corridor: the case of the Po Valley Corridor.The results of this mapping exercise have been evaluated on the background of consolidated knowledge about northern Italy urban patterns, including the Linear Metropolitan System – LiMeS – and preliminary observations about characteristics, potential, and limits of the tool are proposed.

Project management plan : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2010-12-01

The Dallas Integrated Corridor Management System Demonstration Project is a multi-agency, de-centralized operation which will utilize a set of regional systems to integrate the operations of the corridor. The purpose of the Dallas ICM System is to im...

Site-occupany of bats in relation to forested corridors

Science.gov (United States)

Chris D Hein; Steven B Castleberry; Karl V. Miller

2009-01-01

Although use of corridors by some wildlife species has been extensively examined, use by bats is poorly understood. From 1 June to 31 August (2004~200S), we used Anabat II detectors to examine bat activity and species occupancy relative to forested corridors on an intensively managed forest landscape in southern South Carolina, USA. We...

Two-particle spatial correlations in superfluid nuclei

International Nuclear Information System (INIS)

Pillet, N.; Berger, J.-F.; Sandulescu, N.; Schuck, P.

2010-01-01

We discuss the effect of pairing on two-neutron space correlations in deformed nuclei. The spatial correlations are described by the pairing tensor in coordinate space calculated in the HFB approach. Calculations are done using the D1S Gogny force. We show that the pairing tensor has a rather small extension in the relative coordinate, a feature observed earlier in spherical nuclei. It is pointed out that in deformed nuclei the coherence length corresponding to the pairing tensor has a pattern similar to what we have found previously in spherical nuclei; that is, it is maximal in the interior of the nucleus and then it decreases rather rapidly in the surface region, where it reaches a minimal value of about 2 fm. This minimal value of the coherence length in the surface is essentially determined by the finite size properties of single-particle states in the vicinity of the chemical potential and has little to do with enhanced pairing correlations in the nuclear surface. It is shown that in nuclei the coherence length is not a good indicator of the intensity of pairing correlations. This feature is contrasted with the situation in infinite matter.

Application of Transaction Costs in Analyzing Transport Corridors Using Multi-Agent-Based Simulation

Directory of Open Access Journals (Sweden)

Lawrence E. Henesey

2006-03-01

Full Text Available In analyzing the freight transportation systems, such as thetransport of intermodal containers, often direct monetary costsassociated with transportation are used to evaluate or determinethe choice of transport corridor. In forming decisions ontransport co"idor choice, this paper proposes that transactioncosts can be considered as an additional determinant in conductingtransport corridor analysis. The application of transactioncosts theory in analyzing the organizations and the transactionsthat occur, assists in indicating as to which governancestructure results in higher efficiencies. Efficiency is seen as eitherthe minimisation on costs or the maximisation of customerservice levels. The use of multi-agent based simulation for modellingthe organisational structure and mechanisms provides anovel approach in understanding the relationships in a regionaltransport co"idor.

Multilevel discretized random field models with 'spin' correlations for the simulation of environmental spatial data

International Nuclear Information System (INIS)

Žukovič, Milan; Hristopulos, Dionissios T

2009-01-01

A current problem of practical significance is how to analyze large, spatially distributed, environmental data sets. The problem is more challenging for variables that follow non-Gaussian distributions. We show by means of numerical simulations that the spatial correlations between variables can be captured by interactions between 'spins'. The spins represent multilevel discretizations of environmental variables with respect to a number of pre-defined thresholds. The spatial dependence between the 'spins' is imposed by means of short-range interactions. We present two approaches, inspired by the Ising and Potts models, that generate conditional simulations of spatially distributed variables from samples with missing data. Currently, the sampling and simulation points are assumed to be at the nodes of a regular grid. The conditional simulations of the 'spin system' are forced to respect locally the sample values and the system statistics globally. The second constraint is enforced by minimizing a cost function representing the deviation between normalized correlation energies of the simulated and the sample distributions. In the approach based on the N c -state Potts model, each point is assigned to one of N c classes. The interactions involve all the points simultaneously. In the Ising model approach, a sequential simulation scheme is used: the discretization at each simulation level is binomial (i.e., ± 1). Information propagates from lower to higher levels as the simulation proceeds. We compare the two approaches in terms of their ability to reproduce the target statistics (e.g., the histogram and the variogram of the sample distribution), to predict data at unsampled locations, as well as in terms of their computational complexity. The comparison is based on a non-Gaussian data set (derived from a digital elevation model of the Walker Lake area, Nevada, USA). We discuss the impact of relevant simulation parameters, such as the domain size, the number of

Mapping mountain torrent hazards in the Hexi Corridor using an evidential reasoning approach

Science.gov (United States)

Ran, Youhua; Liu, Jinpeng; Tian, Feng; Wang, Dekai

2017-02-01

The Hexi Corridor is an important part of the Silk Road Economic Belt and a crucial channel for westward development in China. Many important national engineering projects pass through the corridor, such as highways, railways, and the West-to-East Gas Pipeline. The frequent torrent disasters greatly impact the security of infrastructure and human safety. In this study, an evidential reasoning approach based on Dempster-Shafer theory is proposed for mapping mountain torrent hazards in the Hexi Corridor. A torrent hazard map for the Hexi Corridor was generated by integrating the driving factors of mountain torrent disasters including precipitation, terrain, flow concentration processes, and the vegetation fraction. The results show that the capability of the proposed method is satisfactory. The torrent hazard map shows that there is high potential torrent hazard in the central and southeastern Hexi Corridor. The results are useful for engineering planning support and resource protection in the Hexi Corridor. Further efforts are discussed for improving torrent hazard mapping and prediction.

Collision risk-capacity tradeoff analysis of an en-route corridor model

Directory of Open Access Journals (Sweden)

Ye Bojia

2014-02-01

Full Text Available Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete–continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational environment. A second-order system is established by combining the point mass model and the proportional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally setting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.

What is The Role of Land Value in The Urban Corridor?

Science.gov (United States)

Rakhmatulloh, A. R.; Buchori, I.; Pradoto, W.; Riyanto, B.; Winarendri, J.

2018-02-01

The high movement causes traffic congestion and indicates high movement intensity along the corridor. The higher attraction of the land use will encourage the higher attraction of movement and economic values in the location. This attraction is also affected by the high mobility in the corridor supported by available transport infrastructure. Thus this causes land values become increase significantly. Land use along the corridor can be seen as commercial function because this activity is able to survive in the premium location. The purpose of this research is to identify the effect of land use change toward land values in the commercial corridor. This research used positivistic method with descriptive analysis. The result shows that the land values change in commercial use in the corridor has different pattern of land use change pattern according to physical condition and land use which causes highly economic attraction. The new commercial land is influenced by the distance to city centre or CBD (Central Business District). Land use and public facilities that have local and city scope services do not give the significant impact to land values change.

Site Outcomes Baseline Multi Year Work Plan Volume 1, River Corridor Restoration Baseline

International Nuclear Information System (INIS)

Wintczak, T.M.

2001-01-01

The River Corridor Restoration volume is a compilation of Hanford Site scope, which excludes the approximately 194 km 2 Central Plateau. The River Corridor scope is currently contractually assigned to Fluor Hanford, Bechtel Hanford, inc., DynCorp, and Pacific Northwest National Laboratory, and others. The purpose of this project specification is to provide an overall scoping document for the River Corridor Restoration volume, and to provide a link with the overall Hanford Site River Corridor scope. Additionally, this specification provides an integrated and consolidated source of information for the various scopes, by current contract, for the River Corridor Restoration Baseline. It identifies the vision, mission, and goals, as well as the operational history of the Hanford Site, along with environmental setting and hazards

Characterizing the spatial variations and correlations of large rainstorms for landslide study

Directory of Open Access Journals (Sweden)

L. Gao

2017-09-01

Full Text Available Rainfall is the primary trigger of landslides in Hong Kong; hence, rainstorm spatial distribution is an important piece of information in landslide hazard analysis. The primary objective of this paper is to quantify spatial correlation characteristics of three landslide-triggering large storms in Hong Kong. The spatial maximum rolling rainfall is represented by a rotated ellipsoid trend surface and a random field of residuals. The maximum rolling 4, 12, 24, and 36 h rainfall amounts of these storms are assessed via surface trend fitting, and the spatial correlation of the detrended residuals is determined through studying the scales of fluctuation along eight directions. The principal directions of the surface trend are between 19 and 43°, and the major and minor axis lengths are 83–386 and 55–79 km, respectively. The scales of fluctuation of the residuals are found between 5 and 30 km. The spatial distribution parameters for the three large rainstorms are found to be similar to those for four ordinary rainfall events. The proposed rainfall spatial distribution model and parameters help define the impact area, rainfall intensity and local topographic effects for landslide hazard evaluation in the future.

„Blue-green“ corridors as a tool for mitigation of natural hazards and restoration of urbanized areas: A case study of Belgrade city

Directory of Open Access Journals (Sweden)

Ristić Ratko

2013-01-01

��blue-green“ corridors at different spatial levels. The final goal is the creation of a network of “blue-green” corridors in the territory of Belgrade city, which provides both effective erosion and stream control and environmental and social services.

Long-term results of the corridor operation for atrial fibrillation

NARCIS (Netherlands)

van Hemel, N. M.; Defauw, J. J.; Kingma, J. H.; Jaarsma, W.; Vermeulen, F. E.; de Bakker, J. M.; Guiraudon, G. M.

1994-01-01

To investigate the long-term results of the corridor operation in the treatment of symptomatic atrial fibrillation refractory to drug treatment. The corridor operation is designed to isolate from the left and right atrium a conduit of atrial tissue connecting the sinus node area with the

Hybrid optical CDMA-FSO communications network under spatially correlated gamma-gamma scintillation.

Science.gov (United States)

Jurado-Navas, Antonio; Raddo, Thiago R; Garrido-Balsells, José María; Borges, Ben-Hur V; Olmos, Juan José Vegas; Monroy, Idelfonso Tafur

2016-07-25

In this paper, we propose a new hybrid network solution based on asynchronous optical code-division multiple-access (OCDMA) and free-space optical (FSO) technologies for last-mile access networks, where fiber deployment is impractical. The architecture of the proposed hybrid OCDMA-FSO network is thoroughly described. The users access the network in a fully asynchronous manner by means of assigned fast frequency hopping (FFH)-based codes. In the FSO receiver, an equal gain-combining technique is employed along with intensity modulation and direct detection. New analytical formalisms for evaluating the average bit error rate (ABER) performance are also proposed. These formalisms, based on the spatially correlated gamma-gamma statistical model, are derived considering three distinct scenarios, namely, uncorrelated, totally correlated, and partially correlated channels. Numerical results show that users can successfully achieve error-free ABER levels for the three scenarios considered as long as forward error correction (FEC) algorithms are employed. Therefore, OCDMA-FSO networks can be a prospective alternative to deliver high-speed communication services to access networks with deficient fiber infrastructure.

Motorcycle On-Road Driving Parameters Influencing Fuel Consumption and Emissions on Congested Signalized Urban Corridor

Directory of Open Access Journals (Sweden)

Atthapol Seedam

2017-01-01

Full Text Available This study aims to find the on-road driving parameters influencing fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor. A motorcycle onboard measurement system was developed to measure instantaneously and continuously record on-road driving data, including speed-time profile, emissions, and fuel consumption, by the second. The test motorcycles were driven by 30 sample motorcyclists on a signalized urban corridor in Khon Kaen City, Thailand, to collect their on-road driving behavior during the morning peak period. Cluster analysis was applied to analyze collected driving data and to categorize the drivers by level of fuel consumption and on-road driver behavior. The on-road driving parameter influencing fuel consumption and emissions was then determined. Results revealed that proportion of idle time significantly influenced fuel consumption and emissions of motorcycle driving on a congested signalized urban corridor, though aggressive driving behavior, hard acceleration and deceleration, did not have the same kind of influence.

Grizzly bears and calving caribou: What is the relation with river corridors?

Science.gov (United States)

Young, Donald D.; McCabe, Thomas R.

1998-01-01

Researchers have debated the effect of the Trans-Alaska Pipeline (TAP) and associated developments to caribou (Rangifer tarandus) of the central Arctic herd (CAH) since the 1970s. Several studies have demonstrated that cows and calves of the CAH avoided the TAP corridor because of disturbance associated with the pipeline, whereas others have indicated that female caribou of the CAH avoided riparian habitats closely associated with the pipeline. This avoidance was explained as a predator-avoidance strategy. We investigated the relation between female caribou and grizzly bear (Ursus arctos) use of river corridors on the yet undisturbed calving grounds of the Porcupine caribou herd (PCH) in northeastern Alaska. On the coastal plain, caribou were closer to river corridors than expected (P = 0.038), but bear use of river corridors did not differ from expected (P = 0.740). In the foothills, caribou use of river corridors did not differ from expected (P = 0.520), but bears were farther from rivers than expected (P = 0.001). Our results did not suggest an avoidance of river corridors by calving caribou or a propensity for bears to be associated with riparian habitats, presumably for stalking or ambush cover. We propose that PCH caribou reduce the risks of predation to neonates by migrating to a common calving grounds, where predator swamping is the operational antipredator strategy. Consequently, we hypothesize that nutritional demands, not predator avoidance strategies, ultimately regulate habitat use patterns (e.g., use of river corridors) of calving PCH caribou.

System acceptance test plan : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2013-02-01

The Dallas Area Rapid Transit (DART) is leading the US 75 Integrated Corridor Management (ICM) : Demonstration Project for the Dallas region. Coordinated corridor operations and management is : predicated on being able to share transportation informa...

Accounting for Non-Gaussian Sources of Spatial Correlation in Parametric Functional Magnetic Resonance Imaging Paradigms II: A Method to Obtain First-Level Analysis Residuals with Uniform and Gaussian Spatial Autocorrelation Function and Independent and Identically Distributed Time-Series.

Science.gov (United States)

Gopinath, Kaundinya; Krishnamurthy, Venkatagiri; Lacey, Simon; Sathian, K

2018-02-01

In a recent study Eklund et al. have shown that cluster-wise family-wise error (FWE) rate-corrected inferences made in parametric statistical method-based functional magnetic resonance imaging (fMRI) studies over the past couple of decades may have been invalid, particularly for cluster defining thresholds less stringent than p functions (sACFs) of fMRI data had been modeled incorrectly to follow a Gaussian form, whereas empirical data suggest otherwise. Hence, the residuals from general linear model (GLM)-based fMRI activation estimates in these studies may not have possessed a homogenously Gaussian sACF. Here we propose a method based on the assumption that heterogeneity and non-Gaussianity of the sACF of the first-level GLM analysis residuals, as well as temporal autocorrelations in the first-level voxel residual time-series, are caused by unmodeled MRI signal from neuronal and physiological processes as well as motion and other artifacts, which can be approximated by appropriate decompositions of the first-level residuals with principal component analysis (PCA), and removed. We show that application of this method yields GLM residuals with significantly reduced spatial correlation, nearly Gaussian sACF and uniform spatial smoothness across the brain, thereby allowing valid cluster-based FWE-corrected inferences based on assumption of Gaussian spatial noise. We further show that application of this method renders the voxel time-series of first-level GLM residuals independent, and identically distributed across time (which is a necessary condition for appropriate voxel-level GLM inference), without having to fit ad hoc stochastic colored noise models. Furthermore, the detection power of individual subject brain activation analysis is enhanced. This method will be especially useful for case studies, which rely on first-level GLM analysis inferences.

Optimizing a desirable fare structure for a bus-subway corridor.

Science.gov (United States)

Liu, Bing-Zheng; Ge, Ying-En; Cao, Kai; Jiang, Xi; Meng, Lingyun; Liu, Ding; Gao, Yunfeng

2017-01-01

This paper aims to optimize a desirable fare structure for the public transit service along a bus-subway corridor with the consideration of those factors related to equity in trip, including travel distance and comfort level. The travel distance factor is represented by the distance-based fare strategy, which is an existing differential strategy. The comfort level one is considered in the area-based fare strategy which is a new differential strategy defined in this paper. Both factors are referred to by the combined fare strategy which is composed of distance-based and area-based fare strategies. The flat fare strategy is applied to determine a reference level of social welfare and obtain the general passenger flow along transit lines, which is used to divide areas or zones along the corridor. This problem is formulated as a bi-level program, of which the upper level maximizes the social welfare and the lower level capturing traveler choice behavior is a variable-demand stochastic user equilibrium assignment model. A genetic algorithm is applied to solve the bi-level program while the method of successive averages is adopted to solve the lower-level model. A series of numerical experiments are carried out to illustrate the performance of the models and solution methods. Numerical results indicate that all three differential fare strategies play a better role in enhancing the social welfare than the flat fare strategy and that the fare structure under the combined fare strategy generates the highest social welfare and the largest resulting passenger demand, which implies that the more equity factors a differential fare strategy involves the more desirable fare structure the strategy has.

Optimizing a desirable fare structure for a bus-subway corridor

Science.gov (United States)

Liu, Bing-Zheng; Ge, Ying-En; Cao, Kai; Jiang, Xi; Meng, Lingyun; Liu, Ding; Gao, Yunfeng

2017-01-01

This paper aims to optimize a desirable fare structure for the public transit service along a bus-subway corridor with the consideration of those factors related to equity in trip, including travel distance and comfort level. The travel distance factor is represented by the distance-based fare strategy, which is an existing differential strategy. The comfort level one is considered in the area-based fare strategy which is a new differential strategy defined in this paper. Both factors are referred to by the combined fare strategy which is composed of distance-based and area-based fare strategies. The flat fare strategy is applied to determine a reference level of social welfare and obtain the general passenger flow along transit lines, which is used to divide areas or zones along the corridor. This problem is formulated as a bi-level program, of which the upper level maximizes the social welfare and the lower level capturing traveler choice behavior is a variable-demand stochastic user equilibrium assignment model. A genetic algorithm is applied to solve the bi-level program while the method of successive averages is adopted to solve the lower-level model. A series of numerical experiments are carried out to illustrate the performance of the models and solution methods. Numerical results indicate that all three differential fare strategies play a better role in enhancing the social welfare than the flat fare strategy and that the fare structure under the combined fare strategy generates the highest social welfare and the largest resulting passenger demand, which implies that the more equity factors a differential fare strategy involves the more desirable fare structure the strategy has. PMID:28981508

Regional Ecological Corridors - MLCCS derived 2008

Data.gov (United States)

Minnesota Department of Natural Resources — Identification of potential ecological corridors between the MLCCS derived ecological patches (ear_eco08py3). This was generated using cost / distance analysis,...

ERA Ranger tailings corridor review. Supervising Scientist report 154

International Nuclear Information System (INIS)

Merz, S.K.

2000-01-01

Sinclair Knight Merz (SKM) were commissioned by the Office of the Supervising Scientist on 25 May 2000 to undertake a review and complete a report on the tailings corridor at the ERA Ranger Mine. The objective of the study was to undertake an 'as is' and to some extent historic and look ahead, review of the corridor system sufficient to: assess the current suitability of key aspects of the design; assess the suitability of current operating, maintenance and system development regimes and responsibilities; and record any recommended actions or further investigations arising out of the review; in order to ensure the adequacy of the design, operation and maintenance. The scope of the study report was limited to the corridor itself, its associated sump and sump contents discharge and the branch corridors carrying pipelines to Pit 1. A representative report contents was discussed and agreed with the Office of the Supervising Scientist prior to commencement of the study and this is included as appendix A to this report. The originally agreed content is, with only minor amendment, reflected in this report. The study methodology comprised a review and assessment by SKM of the design of the existing system and current operations documentation and information obtained from investigations on site and discussions with ERA site personnel. Whilst, a number of modifications affecting the corridor are recommended for further consideration, the main findings of the report relate to operating and maintenance practices which should be adopted for the remainder of the mine/mill life

76 FR 29290 - Environmental Impact Statement: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia

Science.gov (United States)

2011-05-20

...: Interstate 64 Hampton Roads Bridge Tunnel Corridor, Virginia AGENCY: Federal Highway Administration (FHWA... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. FOR FURTHER INFORMATION CONTACT... Interstate 64 Hampton Roads Bridge Tunnel (HRBT) corridor in Virginia. The approximate limits of the study...

Limits to benthic feeding by eiders in a vital Arctic migration corridor due to localized prey and changing sea ice

Science.gov (United States)

Lovvorn, James R.; Rocha, Aariel R.; Jewett, Stephen C.; Dasher, Douglas; Oppel, Steffen; Powell, Abby

2015-01-01

Four species of threatened or declining eider ducks that nest in the Arctic migrate through the northeast Chukchi Sea, where anticipated industrial development may require prioritizing areas for conservation. In this nearshore corridor (10–40 m depth), the eiders’ access to benthic prey during the spring is restricted to variable areas of open water within sea ice. For the most abundant species, the king eider (Somateria spectabilis), stable isotopes in blood cells, muscle, and potential prey indicate that these eiders ate mainly bivalves when traversing this corridor. Bivalves there were much smaller than the same taxa in deeper areas of the northern Bering Sea, possibly due to higher mortality rates caused by ice scour in shallow water; future decrease in seasonal duration of fast ice may increase this effect. Computer simulations suggested that if these eiders forage for >15 h/day, they can feed profitably at bivalve densities >200 m−2 regardless of water depth or availability of ice for resting. Sampling in 2010–2012 showed that large areas of profitable prey densities occurred only in certain locations throughout the migration corridor. Satellite data in April–May over 13 years (2001–2013) indicated that access to major feeding areas through sea ice in different segments of the corridor can vary from 0% to 100% between months and years. In a warming and increasingly variable climate, unpredictability of access may be enhanced by greater effects of shifting winds on unconsolidated ice. Our results indicate the importance of having a range of potential feeding areas throughout the migration corridor to ensure prey availability in all years. Spatial planning of nearshore industrial development in the Arctic, including commercial shipping, pipeline construction, and the risk of released oil, should consider these effects of high environmental variability on the adequacy of habitats targeted for conservation.

Probing heterogeneous dynamics from spatial density correlation in glass-forming liquids.

Science.gov (United States)

Li, Yan-Wei; Zhu, You-Liang; Sun, Zhao-Yan

2016-12-01

We numerically investigate the connection between spatial density correlation and dynamical heterogeneity in glass-forming liquids. We demonstrate that the cluster size defined by the spatial aggregation of densely packed particles (DPPs) can better capture the difference between the dynamics of the Lennard-Jones glass model and the Weeks-Chandler-Andersen truncation model than the commonly used pair correlation functions. More interestingly, we compare the mobility of DPPs and loosely packed particles, and we find that high local density correlates well with slow dynamics in systems with relatively hard repulsive interactions but links to mobile ones in the system with soft repulsive interactions at one relaxation time scale. Our results show clear evidence that the above model dependence behavior stems from the hopping motion of DPPs at the end of the caging stage due to the compressive nature of soft repulsive spheres, which activates the dynamics of DPPs in the α relaxation stage.

Carbon monoxide levels measured in major commuting corridors covering different landuse and roadway microenvironments in Hong Kong

Science.gov (United States)

Chan, L. Y.; Liu, Y. M.; Lee, S. C.; Chan, C. Y.

Vehicle exhaust is the major source of pollutant in modern cities. About half of Hong Kong residents are living in suburban or rural areas. They need to traverse through tunnels, highways, urban street canyons and other road conditions in different landuse areas when they traverse to work in urban centres or new towns. Also, there is increasing traffic, especially trucks across the border between Hong Kong and mainland China via several border highways. This study helps us in assessing the exposure level of suburban and cross border commuters. Carbon monoxide (CO) is used as a tracer for traffic emission. An experimental vehicle traversing major commuting corridors were used to measure CO levels in different landuse and roadway microenvironments including tunnels and highways. The air samples were taken simultaneously at the outside and inside of a travelling vehicle. Result indicates that the pattern of fluctuation of the out-vehicle and in-vehicle CO level vary with different landuse areas. The variation pattern of in-vehicle CO level is closely related to that of out-vehicle level. The effects of the out-vehicle CO concentration on the in-vehicle CO concentration under different roadway conditions in various landuse categories are examined. There is an indication that external air pollutants penetrated into the in-vehicle compartment through car body cracks, ventilation system. From our observation, the exhaust of a nearby petrol vehicle contributed significantly to the in-vehicle CO level. The use of low standard of diesel fuel from Shenzhen in mainland China leads to higher CO level near border area.

Carbon stock corridors to mitigate climate change and promote biodiversity in the tropics

Science.gov (United States)

Jantz, Patrick; Goetz, Scott; Laporte, Nadine

2014-02-01

A key issue in global conservation is how biodiversity co-benefits can be incorporated into land use and climate change mitigation activities, particularly those being negotiated under the United Nations to reduce emissions from tropical deforestation and forest degradation. Protected areas have been the dominant strategy for tropical forest conservation and they have increased substantially in recent decades. Avoiding deforestation by preserving carbon stored in vegetation between protected areas provides an opportunity to mitigate the effects of land use and climate change on biodiversity by maintaining habitat connectivity across landscapes. Here we use a high-resolution data set of vegetation carbon stock to map corridors traversing areas of highest biomass between protected areas in the tropics. The derived corridors contain 15% of the total unprotected aboveground carbon in the tropical region. A large number of corridors have carbon densities that approach or exceed those of the protected areas they connect, suggesting these are suitable areas for achieving both habitat connectivity and climate change mitigation benefits. To further illustrate how economic and biological information can be used for corridor prioritization on a regional scale, we conducted a multicriteria analysis of corridors in the Legal Amazon, identifying corridors with high carbon, high species richness and endemism, and low economic opportunity costs. We also assessed the vulnerability of corridors to future deforestation threat.

Esthetic effect of the buccal corridor size and amount of tooth-gingival display on smile attractiveness in two student population

Directory of Open Access Journals (Sweden)

Hooman Zarif Najafi

2015-05-01

Full Text Available 3- Dentist   Background and Aims: An attractive, well-balanced smile is a paramount treatment objective of the modern orthodontic therapy. The purpose of this study was to determine the effects of the buccal corridor size and tooth-gingival display on the smile esthetics as perceived by two groups of the students.   Materials and Methods: A colored image of a woman frontal posed smile was selected. The image was altered digitally to produce different buccal corridor sizes (6%, 12.5% and 20% and different tooth-gingival displays (maxillary central incisors and 2 mm of gingival, maxillary central incisors and dental papilla and 80% of the maxillary central incisors. The different buccal corridor sizes and tooth-gingival displays were combined to produce 9 images. These altered images were rated by 120 medical and dental students using Visual Analogue Scale (VAS. Data were analyzed using Mann-Whitney test, Pairwise comparison LSD test, Repeated measure MANOVA and ICC (Intraclass Correlation Coefficient.   Results: The smile which had the buccal corridor size of 12.5% and complete incisor display without gingival display received the highest rates among the nine smile images in the dental students group. But in the medical students group the smile with the buccal corridor size of 12.5% and 2 mm gingival display, received the highest rates among the nine smile images. There was no significant difference in judging between the male and female raters for the both groups (P>0.05. The dental students were more critical about the increasing of the gingival display.   Conclusion: In the treatment procedure that may lead to the combination of wide buccal corridor and more tooth-gingival show, more caution should be considered.

Small mammal populations in a restored stream corridor

International Nuclear Information System (INIS)

Wike, L.D.

2000-01-01

An opportunity to study the response of a small mammal community to restoration of a riparian wetland was provided by the Pen Branch project at the Savannah River Site (SRS). Live trapping of small mammals was conducted on six transects at Pen Branch in 1996 and 1998 and at three transects at Meyer's Branch, an unimpacted stream at SRS, in 1997 and 1998. Distributions of rates of capture of the four most common species were both spatially and temporally uneven. Kruskal-Wallis one-way analysis of variance found no significant differences in the relationship of capture rates between species and between treatment and both the within-stream control and Meyers Branch. Habitat use and movement within stream corridors appears to be dependent primarily on species, with age and sex perhaps contributing to preference and distance moved. The lack of differences in capture rates related to transect or treatment may be due to the close proximity of sample transects relative to the movement potential of the species sampled

Valuation of travel time savings for intercity travel: The Madrid-Barcelona corridor

DEFF Research Database (Denmark)

Roman, Concepcion; Carlos Martin, Juan; Espino, Raquel

2014-01-01

We derive values of travel time savings (VOT) for the Madrid-Barcelona corridor, linking the two largest cities in Spain, based on the estimation of discrete choice models among the main public transport services in the corridor: air transport, high speed rail (HSR) and bus. The new HSR alternative...... (which started to operate in February 2008) competes directly with one of the densest airline domestic markets in the world, and its introduction produced substantial improvements in level of service, achieving reductions in travel time of more than 50% over the conventional train. A specifically...... to provide useful information to quantify users' benefits during the lifespan of a given project. We found, as expected, that HSR and air transport users exhibit substantially higher values for saving travel time than bus travellers. Also as expected, savings of waiting time are more valued than savings...

China Pakistan Economic Corridor (CPEC): Benefits For Pakistan And Comparison With Suez And Panama Canals

Science.gov (United States)

2017-12-01

ECONOMIC CORRIDOR (CPEC): BENEFITS FOR PAKISTAN AND COMPARISON WITH SUEZ AND PANAMA CANALS by Hanif Ullah Khan December 2017 Thesis...DATE December 2017 3. REPORT TYPE AND DATES COVERED Master’s thesis 4. TITLE AND SUBTITLE CHINA PAKISTAN ECONOMIC CORRIDOR (CPEC): BENEFITS FOR...The China Pakistan Economic Corridor (CPEC) is part of China’s “One Belt, One Road” initiative and joins two major economic corridors: The Silk Road

Effect of spatially correlated noise on coherence resonance in a network of excitable cells

International Nuclear Information System (INIS)

Kwon, Okyu; Jo, Hang-Hyun; Moon, Hie-Tae

2005-01-01

We study the effect of spatially correlated noise on coherence resonance (CR) in a Watts-Strogatz small-world network of Fitz Hugh-Nagumo neurons, where the noise correlation decays exponentially with distance between neurons. It is found that CR is considerably improved just by a small fraction of long-range connections for an intermediate coupling strength. For other coupling strengths, an abrupt change in CR occurs following the drastic fracture of the clustered structures in the network. Our study shows that spatially correlated noise plays a significant role in the phenomenon of CR reinforcing the role of the clustered structure of the system

Quantum diffraction and interference of spatially correlated photon pairs and its Fourier-optical analysis

International Nuclear Information System (INIS)

Shimizu, Ryosuke; Edamatsu, Keiichi; Itoh, Tadashi

2006-01-01

We present one- and two-photon diffraction and interference experiments involving parametric down-converted photon pairs. By controlling the divergence of the pump beam in parametric down-conversion, the diffraction-interference pattern produced by an object changes from a quantum (perfectly correlated) case to a classical (uncorrelated) one. The observed diffraction and interference patterns are accurately reproduced by Fourier-optical analysis taking into account the quantum spatial correlation. We show that the relation between the spatial correlation and the object size plays a crucial role in the formation of both one- and two-photon diffraction-interference patterns

Value of semi-open corridors for simultaneously connecting open and wooded habitats: a case study with ground beetles.

Science.gov (United States)

Eggers, Britta; Matern, Andrea; Drees, Claudia; Eggers, Jan; Härdtle, Werner; Assmann, Thorsten

2010-02-01

To counteract habitat fragmentation, the connectivity of a landscape should be enhanced. Corridors are thought to facilitate movement between disconnected patches of habitat, and linear strips of habitat connecting isolated patches are a popular type of corridor. On the other hand, the creation of new corridors can lead to fragmentation of the surrounding habitat. For example, heathland corridors connect patches of heathland and alternatively hedgerows connect patches of woodland. Nevertheless, these corridors themselves also break up previously connected patches of their surrounding habitat and in so doing fragment another type of habitat (heathland corridors fragment woodlands and woodland strips or hedgerows fragment heathlands). To overcome this challenge we propose the use of semi-open habitats (a mixture of heathland and woodland vegetation) as conservation corridors to enable dispersal of both stenotopic heathland and woodland species. We used two semi-open corridors with a mosaic of heathland and woody vegetation to investigate the efficiency of semi-open corridors for species dispersal and to assess whether these corridors might be a suitable approach for nature conservation. We conducted a mark-recapture study on three stenotopic flightless carabid beetles of heathlands and woodlands and took an inventory of all the carabid species in two semi-open corridors. Both methodological approaches showed simultaneous immigration of woodland and heathland species in the semi-open corridor. Detrended correspondence analysis showed a clear separation of the given habitats and affirmed that semi-open corridors are a good strategy for connecting woodlands and heathlands. The best means of creating and preserving semi-open corridors is probably through extensive grazing.

Identification of functional corridors with movement characteristics of brown bears on the Kenai Peninsula, Alaska

Science.gov (United States)

Graves, T.A.; Farley, S.; Goldstein, M.I.; Servheen, C.

2007-01-01

We identified primary habitat and functional corridors across a landscape using Global Positioning System (GPS) collar locations of brown bears (Ursus arctos). After deriving density, speed, and angular deviation of movement, we classified landscape function for a group of animals with a cluster analysis. We described areas with high amounts of sinuous movement as primary habitat patches and areas with high amounts of very directional, fast movement as highly functional bear corridors. The time between bear locations and scale of analysis influenced the number and size of corridors identified. Bear locations should be collected at intervals ???6 h to correctly identify travel corridors. Our corridor identification technique will help managers move beyond the theoretical discussion of corridors and linkage zones to active management of landscape features that will preserve connectivity. ?? 2007 Springer Science+Business Media, Inc.

The Western Energy Corridor Initiative: Unconventional Fuel Development Issues, Impacts, and Management Assessment

Science.gov (United States)

Wolfsberg, A.; Hagood, M.; Pasqualini, D.; Wood, T.; Wilson, C.; Witkowski, M.; Levitt, D.; Pawar, R.; Keating, G.; Ziock, H.

2008-12-01

The United States is increasingly dependent on imported oil and gas; commodities for which other nations are competing and for which future supply may be inadequate to support our transportation fuel needs. Therefore, a renewed interest in 'harder-to-get' unconventional fuels has emerged in both industry and government with directed focus on world class hydrocarbon resources within a corridor extending from Canada southward through the Rocky Mountain States. Within this Western Energy Corridor, co-located with significant conventional hydrocarbon and renewable energy resources, lie some of the world's richest unconventional hydrocarbon resources in oil shales, oil sands and coal for coal-to-liquid conversion. However, development of these resources poses substantial environmental concerns as well as increasing competition for limited resources of water and habitat. With large-scale energy development in the predominantly rural region, local communities, infrastructures, and economies will face increasing demands for roads, electricity, law enforcement, labor, and other support services. The Western Energy Corridor Initiative (WECI) seeks to develop an integrated assessment of the impacts of unconventional fuel development, the interrelationships of planned energy developments in different basins, and the resultant demands placed on the region. This initial WECI study focuses on two of the most important current issues for industry, regulators, and stakeholders -- the assessment of carbon and water resources issues, impacts, and management strategies. Through scenario analyses using coupled systems and process level models, this study investigates the viability of integrated development of multiple energy resources in a carbon neutral and environmentally acceptable manner, and the interrelationships of various energy resource development plans. The modeling framework is designed to extend to include infrastructure, employment, training, fiscal and economic demands

The role of green corridors for wildlife conservation in urban landscape: A literature review

International Nuclear Information System (INIS)

Aziz, H A; Rasidi, M H

2014-01-01

Green corridors are an attempt to mitigate negative effects of the built environment of cities and towns. The corridors act as conservation for rapidly extreme intervention and development of the urban environment. Most importantly, it enables dispersal movement of animals within city areas. Issues relate to wildlife conservation in urban areas has been studied for many years and thus, the research makes a review for how the green corridors contribute to the conservation of urban wildlife. This study reviews groups of articles in disciplines of urban landscape planning and biology conservation to discuss the relationship between elements of green corridors and urban wildlife dispersal movement behaviour in Malaysian context. Accordingly, this research is purposely studied to give understanding on how green corridors contribute to the animals' ability of moving and dispersing within the built-up areas. In advance, it is found that there are three factors contribute to the capability of colonization among urban wildlife which are individual, physical and social factor. Green corridor has been defined as one of the physical factor that influence urban wildlife behaviour movement. Consequently, safety area indicating to animals species for traversing in any time such as at night can be defined as the primary potential corridor

Dynamic habitat corridors for marine predators; intensive use of a coastal channel by harbour seals is modulated by tidal currents.

Science.gov (United States)

Hastie, Gordon D; Russell, Deborah J F; Benjamins, Steven; Moss, Simon; Wilson, Ben; Thompson, Dave

2016-01-01

Previous studies have found that predators utilise habitat corridors to ambush prey moving through them. In the marine environment, coastal channels effectively act as habitat corridors for prey movements, and sightings of predators in such areas suggest that they may target these for foraging. Unlike terrestrial systems where the underlying habitat structure is generally static, corridors in marine systems are in episodic flux due to water movements created by tidal processes. Although these hydrographic features can be highly complex, there is generally a predictable underlying cyclic tidal pattern to their structure. For marine predators that must find prey that is often patchy and widely distributed, the underlying temporal predictability in potential foraging opportunities in marine corridors may be important drivers in their use. Here, we used data from land-based sightings and 19 harbour seals ( Phoca vitulina ) tagged with high-resolution GPS telemetry to investigate the spatial and temporal distribution patterns of seals in a narrow tidal channel. These seals showed a striking pattern in their distribution; all seals spent a high proportion of their time around the narrowest point of the channel. There was also a distinctive tidal pattern in the use of the channel; sightings of seals in the water peaked during the flood tide and were at a minimum during the ebb tide. This pattern is likely to be related to prey availability and/or foraging efficiency driven by the underlying tidal pattern in the water movements through the channel. To maximise foraging efficiency, predators often make use of narrow constrictions in habitat to intercept prey using these corridors for movement. In the marine environment, narrow channels may act as corridors, and sightings of predators suggest that they may target these for foraging. Despite this, there is little information on how individual predators use such areas. Here, we investigate how individual harbour seals use a

The value of corridor in flat as place attachment in the life of the dwellers

Science.gov (United States)

Arifin, Lilianny; Widigdo, Wanda K.; Juniwati, Anik; Mintorogo, Danny

2017-06-01

Place attachment has been examined extensively in the behavioral and architecture studies over the past two decades. In the production of housing, designers mainly focus on the quality of the physical components. Place attachment is just the form of connection between a person and the environmental setting. However, it was challenging for this study to grasp the aspects of meanings and attachment, both in the level of personal, community and natural environment contexts, which are not adequately considered in the design process. In this study, three-dimensional model of personal and community attachments to their corridor in the flat was conceptually and empirically examined. The aim is to test an integrated approach to measuring place attachment at the corridor in flat in understanding the values of locations in the life of the dwellers. Sample cases included the examination of attachment to the hallway in three units located in Surabaya, Indonesia. It found out that the value of corridor as a place was affected by the daily experience of the places, social bonding, neighborhood interaction, and landscape values.

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks

Science.gov (United States)

Bistra Dilkina; Rachel Houtman; Carla P. Gomes; Claire A. Montgomery; Kevin S. McKelvey; Katherine Kendall; Tabitha A. Graves; Richard Bernstein; Michael K. Schwartz

2016-01-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a...

What Do They Have in Common? Drivers of Streamflow Spatial Correlation and Prediction of Flow Regimes in Ungauged Locations

Science.gov (United States)

Betterle, A.; Radny, D.; Schirmer, M.; Botter, G.

2017-12-01

The spatial correlation of daily streamflows represents a statistical index encapsulating the similarity between hydrographs at two arbitrary catchment outlets. In this work, a process-based analytical framework is utilized to investigate the hydrological drivers of streamflow spatial correlation through an extensive application to 78 pairs of stream gauges belonging to 13 unregulated catchments in the eastern United States. The analysis provides insight on how the observed heterogeneity of the physical processes that control flow dynamics ultimately affect streamflow correlation and spatial patterns of flow regimes. Despite the variability of recession properties across the study catchments, the impact of heterogeneous drainage rates on the streamflow spatial correlation is overwhelmed by the spatial variability of frequency and intensity of effective rainfall events. Overall, model performances are satisfactory, with root mean square errors between modeled and observed streamflow spatial correlation below 10% in most cases. We also propose a method for estimating streamflow correlation in the absence of discharge data, which proves useful to predict streamflow regimes in ungauged areas. The method consists in setting a minimum threshold on the modeled flow correlation to individuate hydrologically similar sites. Catchment outlets that are most correlated (ρ>0.9) are found to be characterized by analogous streamflow distributions across a broad range of flow regimes.

Extending Correlation Filter-Based Visual Tracking by Tree-Structured Ensemble and Spatial Windowing.

Science.gov (United States)

Gundogdu, Erhan; Ozkan, Huseyin; Alatan, A Aydin

2017-11-01

Correlation filters have been successfully used in visual tracking due to their modeling power and computational efficiency. However, the state-of-the-art correlation filter-based (CFB) tracking algorithms tend to quickly discard the previous poses of the target, since they consider only a single filter in their models. On the contrary, our approach is to register multiple CFB trackers for previous poses and exploit the registered knowledge when an appearance change occurs. To this end, we propose a novel tracking algorithm [of complexity O(D) ] based on a large ensemble of CFB trackers. The ensemble [of size O(2 D ) ] is organized over a binary tree (depth D ), and learns the target appearance subspaces such that each constituent tracker becomes an expert of a certain appearance. During tracking, the proposed algorithm combines only the appearance-aware relevant experts to produce boosted tracking decisions. Additionally, we propose a versatile spatial windowing technique to enhance the individual expert trackers. For this purpose, spatial windows are learned for target objects as well as the correlation filters and then the windowed regions are processed for more robust correlations. In our extensive experiments on benchmark datasets, we achieve a substantial performance increase by using the proposed tracking algorithm together with the spatial windowing.

High spatial correspondence at a columnar level between activation and resting state fMRI signals and local field potentials.

Science.gov (United States)

Shi, Zhaoyue; Wu, Ruiqi; Yang, Pai-Feng; Wang, Feng; Wu, Tung-Lin; Mishra, Arabinda; Chen, Li Min; Gore, John C

2017-05-16

Although blood oxygenation level-dependent (BOLD) fMRI has been widely used to map brain responses to external stimuli and to delineate functional circuits at rest, the extent to which BOLD signals correlate spatially with underlying neuronal activity, the spatial relationships between stimulus-evoked BOLD activations and local correlations of BOLD signals in a resting state, and whether these spatial relationships vary across functionally distinct cortical areas are not known. To address these critical questions, we directly compared the spatial extents of stimulated activations and the local profiles of intervoxel resting state correlations for both high-resolution BOLD at 9.4 T and local field potentials (LFPs), using 98-channel microelectrode arrays, in functionally distinct primary somatosensory areas 3b and 1 in nonhuman primates. Anatomic images of LFP and BOLD were coregistered within 0.10 mm accuracy. We found that the point spread functions (PSFs) of BOLD and LFP responses were comparable in the stimulus condition, and both estimates of activations were slightly more spatially constrained than local correlations at rest. The magnitudes of stimulus responses in area 3b were stronger than those in area 1 and extended in a medial to lateral direction. In addition, the reproducibility and stability of stimulus-evoked activation locations within and across both modalities were robust. Our work suggests that the intrinsic resolution of BOLD is not a limiting feature in practice and approaches the intrinsic precision achievable by multielectrode electrophysiology.

Universal Spatial Correlation Functions for Describing and Reconstructing Soil Microstructure

Science.gov (United States)

Skvortsova, Elena B.; Mallants, Dirk

2015-01-01

Structural features of porous materials such as soil define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, or gas exchange between biologically active soil root zone and atmosphere) and solute transport. To characterize soil microstructure, conventional soil science uses such metrics as pore size and pore-size distributions and thin section-derived morphological indicators. However, these descriptors provide only limited amount of information about the complex arrangement of soil structure and have limited capability to reconstruct structural features or predict physical properties. We introduce three different spatial correlation functions as a comprehensive tool to characterize soil microstructure: 1) two-point probability functions, 2) linear functions, and 3) two-point cluster functions. This novel approach was tested on thin-sections (2.21×2.21 cm2) representing eight soils with different pore space configurations. The two-point probability and linear correlation functions were subsequently used as a part of simulated annealing optimization procedures to reconstruct soil structure. Comparison of original and reconstructed images was based on morphological characteristics, cluster correlation functions, total number of pores and pore-size distribution. Results showed excellent agreement for soils with isolated pores, but relatively poor correspondence for soils exhibiting dual-porosity features (i.e. superposition of pores and micro-cracks). Insufficient information content in the correlation function sets used for reconstruction may have contributed to the observed discrepancies. Improved reconstructions may be obtained by adding cluster and other correlation functions into reconstruction sets. Correlation functions and the associated stochastic reconstruction algorithms introduced here are universally applicable in soil science, such as for soil classification

Spatial Correlation in the Ambient Core Noise Field of a Turbofan Engine

Science.gov (United States)

Miles, Jeffrey Hilton

2012-01-01

An acoustic transfer function relating combustion noise and turbine exit noise in the presence of enclosed ambient core noise is investigated using a dynamic system model and an acoustic system model for the particular turbofan engine studied and for a range of operating conditions. Measurements of cross-spectra magnitude and phase between the combustor and turbine exit and auto-spectra at the turbine exit and combustor are used to show the presence of indirect and direct combustion noise over the frequency range of 0 400 Hz. The procedure used evaluates the ratio of direct to indirect combustion noise. The procedure used also evaluates the post-combustion residence time in the combustor which is a factor in the formation of thermal NOx and soot in this region. These measurements are masked by the ambient core noise sound field in this frequency range which is observable since the transducers are situated within an acoustic wavelength of one another. An ambient core noise field model based on one and two dimensional spatial correlation functions is used to replicate the spatially correlated response of the pair of transducers. The spatial correlation function increases measured attenuation due to destructive interference and masks the true attenuation of the turbine.

Streamlining Transportation Corridors Planning Processes and Validating the Application of Commercial Remote Sensing and Spatial Information (CRS-SI) Technologies for Environmental Impact Assessments

Science.gov (United States)

2008-02-05

The new US DOT RITA program has selected MSU for addressing corridor planning and environmental assessment in new and innovative ways that can be compared to traditional approaches. Our primary focus is on the application and validation of new and in...

The Effect of Spatial Interference Correlation and Jamming on Secrecy in Cellular Networks

KAUST Repository

Ali, Konpal S.

2017-06-02

Recent studies on secure wireless communication have shed light on a scenario where interference has a desirable impact on network performance. Particularly, assuming independent interference-power fluctuations at the eavesdropper and the receiver, opportunistic secure-information transfer can occur on the legitimate-link. However, interference is spatially correlated due to the common set of interfering sources, which may diminish the opportunistic-secure-spectrum-access (OSSA) probability. We study and quantify the effect of spatial interference correlation on OSSA in cellular-networks and investigate the potential of full-duplex jamming (FDJ) solutions. The results highlight the scenarios where FDJ improves OSSA performance.

The Effect of Spatial Interference Correlation and Jamming on Secrecy in Cellular Networks

KAUST Repository

Ali, Konpal S.; Elsawy, Hesham; Haenggi, Martin; Alouini, Mohamed-Slim

2017-01-01

Recent studies on secure wireless communication have shed light on a scenario where interference has a desirable impact on network performance. Particularly, assuming independent interference-power fluctuations at the eavesdropper and the receiver, opportunistic secure-information transfer can occur on the legitimate-link. However, interference is spatially correlated due to the common set of interfering sources, which may diminish the opportunistic-secure-spectrum-access (OSSA) probability. We study and quantify the effect of spatial interference correlation on OSSA in cellular-networks and investigate the potential of full-duplex jamming (FDJ) solutions. The results highlight the scenarios where FDJ improves OSSA performance.

Effects of corridors on home range sizes and interpatch movements of three small mammal species.

Energy Technology Data Exchange (ETDEWEB)

Mabry, Karen, E.; Barrett, Gary, W.

2002-04-30

Mabry, K.E., and G.W. Barrett. 2002. Effects of corridors on home range sizes and interpatch movements of three small mammal species. Landscape Ecol. 17:629-636. Corridors are predicted to benefit populations in patchy habitats by promoting movement, which should increase population densities, gene flow, and recolonization of extinct patch populations. However, few investigators have considered use of the total landscape, particularly the possibility of interpatch movement through matrix habitat, by small mammals. This study compares home range sizes of 3 species of small mammals, the cotton mouse, old field mouse and cotton rat between patches with and without corridors. Corridor presence did not have a statistically significant influence on average home range size. Habitat specialization and sex influenced the probability of an individual moving between 2 patches without corridors. The results of this study suggest that small mammals may be more capable of interpatch movement without corridors than is frequently assumed.

Utilisation of spatial and temporal correlations in positron emission tomography

International Nuclear Information System (INIS)

Sureau, F.

2008-06-01

In this thesis we propose, implement, and evaluate algorithms improving spatial resolution in reconstructed images and reducing data noise in positron emission tomography imaging. These algorithms have been developed for a high resolution tomograph (HRRT) and applied to brain imaging, but can be used for other tomographs or studies. We first developed an iterative reconstruction algorithm including a stationary and isotropic model of resolution in image space, experimentally measured. We evaluated the impact of such a model of resolution in Monte-Carlo simulations, physical phantom experiments and in two clinical studies by comparing our algorithm with a reference reconstruction algorithm. This study suggests that biases due to partial volume effects are reduced, in particular in the clinical studies. Better spatial and temporal correlations are also found at the voxel level. However, other methods should be developed to further reduce data noise. We then proposed a maximum a posteriori de-noising algorithm that can be used for dynamic data to de-noise temporally raw data (sino-grams) or reconstructed images. The a priori modeled the coefficients in a wavelet basis of all the signals without noise (in an image or sinogram). We compared this technique with a reference de-noising method on replicated simulations. This illustrates the potential benefits of our approach of sinogram de-noising. (author)

Requirements Definition for ORNL Trusted Corridors Project

Energy Technology Data Exchange (ETDEWEB)

Walker, Randy M [ORNL; Hill, David E [ORNL; Smith, Cyrus M [ORNL; DeNap, Frank A [ORNL; White, James D [ORNL; Gross, Ian G [ORNL; Gorman, Bryan L [ORNL; Hively, Lee M [ORNL; Abercrombie, Robert K [ORNL

2008-02-01

The ORNL Trusted Corridors Project has several other names: SensorNet Transportation Pilot; Identification and Monitoring of Radiation (in commerce) Shipments (IMR(ic)S); and Southeastern Transportation Corridor Pilot (SETCP). The project involves acquisition and analysis of transportation data at two mobile and three fixed inspection stations in five states (Kentucky, Mississippi, South Carolina, Tennessee, and Washington DC). Collaborators include the State Police organizations that are responsible for highway safety, law enforcement, and incident response. The three states with fixed weigh-station deployments (KY, SC, TN) are interested in coordination of this effort for highway safety, law enforcement, and sorting/targeting/interdiction of potentially non-compliant vehicles/persons/cargo. The Domestic Nuclear Detection Office (DNDO) in the U.S. Department of Homeland Security (DHS) is interested in these deployments, as a Pilot test (SETCP) to identify Improvised Nuclear Devices (INDs) in highway transport. However, the level of DNDO integration among these state deployments is presently uncertain. Moreover, DHS issues are considered secondary by the states, which perceive this work as an opportunity to leverage these (new) dual-use technologies for state needs. In addition, present experience shows that radiation detectors alone cannot detect DHS-identified IND threats. Continued SETCP success depends on the level of integration of current state/local police operations with the new DHS task of detecting IND threats, in addition to emergency preparedness and homeland security. This document describes the enabling components for continued SETCP development and success, including: sensors and their use at existing deployments (Section 1); personnel training (Section 2); concept of operations (Section 3); knowledge discovery from the copious data (Section 4); smart data collection, integration and database development, advanced algorithms for multiple sensors, and

Requirements Definition for ORNL Trusted Corridors Project

International Nuclear Information System (INIS)

Walker, Randy M; Hill, David E; Smith, Cyrus M; DeNap, Frank A; White, James D; Gross, Ian G; Gorman, Bryan L; Hively, Lee M; Abercrombie, Robert K

2008-01-01

The ORNL Trusted Corridors Project has several other names: SensorNet Transportation Pilot; Identification and Monitoring of Radiation (in commerce) Shipments (IMR(ic)S); and Southeastern Transportation Corridor Pilot (SETCP). The project involves acquisition and analysis of transportation data at two mobile and three fixed inspection stations in five states (Kentucky, Mississippi, South Carolina, Tennessee, and Washington DC). Collaborators include the State Police organizations that are responsible for highway safety, law enforcement, and incident response. The three states with fixed weigh-station deployments (KY, SC, TN) are interested in coordination of this effort for highway safety, law enforcement, and sorting/targeting/interdiction of potentially non-compliant vehicles/persons/cargo. The Domestic Nuclear Detection Office (DNDO) in the U.S. Department of Homeland Security (DHS) is interested in these deployments, as a Pilot test (SETCP) to identify Improvised Nuclear Devices (INDs) in highway transport. However, the level of DNDO integration among these state deployments is presently uncertain. Moreover, DHS issues are considered secondary by the states, which perceive this work as an opportunity to leverage these (new) dual-use technologies for state needs. In addition, present experience shows that radiation detectors alone cannot detect DHS-identified IND threats. Continued SETCP success depends on the level of integration of current state/local police operations with the new DHS task of detecting IND threats, in addition to emergency preparedness and homeland security. This document describes the enabling components for continued SETCP development and success, including: sensors and their use at existing deployments (Section 1); personnel training (Section 2); concept of operations (Section 3); knowledge discovery from the copious data (Section 4); smart data collection, integration and database development, advanced algorithms for multiple sensors, and

Seasonal Dynamics of River Corridor Exchange Across the Continental United States

Science.gov (United States)

Gomez-Velez, J. D.; Harvey, J. W.; Scott, D.; Boyer, E. W.; Schmadel, N. M.

2017-12-01

River corridors store and convey mass and energy from landscapes to the ocean, altering water quality and ecosystem functioning at the local, reach, and watershed scales. As water moves through river corridors from headwaters streams to coastal estuaries, dynamic exchange between the river channel and its adjacent riparian, floodplain, and hyporheic zones, combined with ponded waters such as lakes and reservoirs, results in the emergence of hot spots and moments for biogeochemical transformations. In this work, we used the model Networks with EXchange and Subsurface Storage (NEXSS) to estimate seasonal variations in river corridor exchange fluxes and residence times along the continental United States. Using a simple routing scheme, we translate these estimates into a cumulative measure of river corridor connectivity at the watershed scale, differentiating the contributions of hyporheic zones, floodplains, and ponded waters. We find that the relative role of these exchange subsystems changes seasonally, driven by the intra-seasonal variability of discharge. In addition, we find that seasonal variations in discharge and the biogeochemical potential of hyporheic zones are out of phase. This behavior results in a significant reduction in hyporheic water quality functions during high flows and emphasizes the potential importance of reconnecting floodplains for managing water quality during seasonal high flows. Physical parameterizations of river corridor processes are critical to model and predict water quality and to sustainably manage water resources under present and future socio-economic and climatic conditions. Parsimonious models like NEXSS can play a key role in the design, implementation, and evaluation of sustainable management practices that target both water quantity and quality at the scale of the nation. This research is a product of the John Wesley Powell Center River Corridor Working Group.

Monte Carlo power iteration: Entropy and spatial correlations

International Nuclear Information System (INIS)

Nowak, Michel; Miao, Jilang; Dumonteil, Eric; Forget, Benoit; Onillon, Anthony; Smith, Kord S.; Zoia, Andrea

2016-01-01

Highlights: • We show that the entropy function might be misleading in criticality simulations. • We interpret the spatial fluctuations of the fission chains in terms of the key parameters of the simulated system. • We show that the behavior of the entropy function is related to the theory of neutron clustering. - Abstract: The behavior of Monte Carlo criticality simulations is often assessed by examining the convergence of the so-called entropy function. In this work, we shall show that the entropy function may lead to a misleading interpretation, and that potential issues occur when spatial correlations induced by fission events are important. We will support our analysis by examining the higher-order moments of the entropy function and the center of mass of the neutron population. Within the framework of a simplified model based on branching processes, we will relate the behavior of the spatial fluctuations of the fission chains to the key parameters of the simulated system, namely, the number of particles per generation, the reactor size and the migration area. Numerical simulations of a fuel rod and of a whole core suggest that the obtained results are quite general and hold true also for real-world applications.

Effects of weighting schemes on the identification of wildlife corridors generated with least-cost methods

Science.gov (United States)

Sean A. Parks; Kevin S. McKelvey; Michael K. Schwartz

2012-01-01

The importance of movement corridors for maintaining connectivity within metapopulations of wild animals is a cornerstone of conservation. One common approach for determining corridor locations is least-cost corridor (LCC) modeling, which uses algorithms within a geographic information system to search for routes with the lowest cumulative resistance between target...

Optimal Corridor Selection for a Road Space Management Strategy: Methodology and Tool

Directory of Open Access Journals (Sweden)

Sushant Sharma

2017-01-01

Full Text Available Nationwide, there is a growing realization that there are valuable benefits to using the existing roadway facilities to their full potential rather than expanding capacity in a traditional way. Currently, state DOTs are looking for cost-effective transportation solutions to mitigate the growing congestion and increasing funding gaps. Innovative road space management strategies like narrowing of multiple lanes (three or more and shoulder width to add a lane enhance the utilization while eliminating the costs associated with constructing new lanes. Although this strategy (among many generally leads to better mobility, identifying optimal corridors is a challenge and may affect the benefits. Further, there is a likelihood that added capacity may provide localized benefits, at the expense of system level performance measures (travel time and crashes because of the relocation of traffic operational bottlenecks. This paper develops a novel transportation programming and investment decision method to identify optimal corridors for adding capacity in the network by leveraging lane widths. The methodology explicitly takes into consideration the system level benefits and safety. The programming compares two conflicting objectives of system travel time and safety benefits to find an optimal solution.

Vegetation Changes along the Qinghai-Tibet Plateau Engineering Corridor Since 2000 Induced by Climate Change and Human Activities

Directory of Open Access Journals (Sweden)

Yi Song

2018-01-01

Full Text Available The Qinghai-Tibet (QT Plateau Engineering Corridor is located in the hinterland of the QT Plateau, which is highly sensitive to global climate change. Climate change causes permafrost degradation, which subsequently affects vegetation growth. This study focused on the vegetation dynamics and their relationships with climate change and human activities in the region surrounding the QT Plateau Engineering Corridor. The vegetation changes were inferred by applying trend analysis, the Mann-Kendall trend test and abrupt change analysis. Six key regions, each containing 40 nested quadrats that ranged in size from 500 × 500 m to 20 × 20 km, were selected to determine the spatial scales of the impacts from different factors. Cumulative growing season integrated enhanced vegetation index (CGSIEVI values were calculated for each of the nested quadrats of different sizes to indicate the overall vegetation state over the entire year at different spatial scales. The impacts from human activities, a sudden increase in precipitation and permafrost degradation were quantified at different spatial scales using the CGSIEVI values and meteorological data based on the double mass curve method. Three conclusions were derived. First, the vegetation displayed a significant increasing trend over 23.6% of the study area. The areas displaying increases were mainly distributed in the Hoh Xil. Of the area where the vegetation displayed a significant decreasing trend, 72.4% was made up of alpine meadows. Second, more vegetation, especially the alpine meadows, has begun to degenerate or experience more rapid degradation since 2007 due to permafrost degradation and overgrazing. Finally, an active layer depth of 3 m to 3.2 m represents a limiting depth for alpine meadows.

VT Electric Transmission Line Corridors - substation points

Data.gov (United States)

Vermont Center for Geographic Information — (Link to Metadata) The ELTRN layer depicts electric transmission line corridors in Vermont. Various methods have been used to digitize features. The data layer...

Tools for Multimode Quantum Information: Modulation, Detection, and Spatial Quantum Correlations

DEFF Research Database (Denmark)

Lassen, Mikael Østergaard; Delaubert, Vincent; Janousek, Jirí

2007-01-01

We present here all the tools required for continuous variable parallel quantum information protocols based on spatial multi-mode quantum correlations and entanglement. We describe techniques for encoding and detecting this quantum information with high efficiency in the individual modes. We use ...

Correlation of spatial climate/weather maps and the advantages of using the Mahalanobis metric in predictions

Science.gov (United States)

Stephenson, D. B.

1997-10-01

The skill in predicting spatially varying weather/climate maps depends on the definition of the measure of similarity between the maps. Under the justifiable approximation that the anomaly maps are distributed multinormally, it is shown analytically that the choice of weighting metric, used in defining the anomaly correlation between spatial maps, can change the resulting probability distribution of the correlation coefficient. The estimate of the numbers of degrees of freedom based on the variance of the correlation distribution can vary from unity up to the number of grid points depending on the choice of weighting metric. The (pseudo-) inverse of the sample covariance matrix acts as a special choice for the metric in that it gives a correlation distribution which has minimal kurtosis and maximum dimension. Minimal kurtosis suggests that the average predictive skill might be improved due to the rarer occurrence of troublesome outlier patterns far from the mean state. Maximum dimension has a disadvantage for analogue prediction schemes in that it gives the minimum number of analogue states. This metric also has an advantage in that it allows one to powerfully test the null hypothesis of multinormality by examining the second and third moments of the correlation coefficient which were introduced by Mardia as invariant measures of multivariate kurtosis and skewness. For these reasons, it is suggested that this metric could be usefully employed in the prediction of weather/climate and in fingerprinting anthropogenic climate change. The ideas are illustrated using the bivariate example of the observed monthly mean sea-level pressures at Darwin and Tahitifrom 1866 1995.

75 FR 70962 - California Green Trade Corridor Transportation Investment Generating Economic Recovery (TIGER)

Science.gov (United States)

2010-11-19

... DEPARTMENT OF TRANSPORTATION Maritime Administration [Docket Number 2010-0103] California Green Trade Corridor Transportation Investment Generating Economic Recovery (TIGER) AGENCY: Department of... California Green Trade Corridor Transportation Investment Generating Economic Recovery (TIGER) grant. An...

Understanding structure of urban traffic network based on spatial-temporal correlation analysis

Science.gov (United States)

Yang, Yanfang; Jia, Limin; Qin, Yong; Han, Shixiu; Dong, Honghui

2017-08-01

Understanding the structural characteristics of urban traffic network comprehensively can provide references for improving road utilization rate and alleviating traffic congestion. This paper focuses on the spatial-temporal correlations between different pairs of traffic series and proposes a complex network-based method of constructing the urban traffic network. In the network, the nodes represent road segments, and an edge between a pair of nodes is added depending on the result of significance test for the corresponding spatial-temporal correlation. Further, a modified PageRank algorithm, named the geographical weight-based PageRank algorithm (GWPA), is proposed to analyze the spatial distribution of important segments in the road network. Finally, experiments are conducted by using three kinds of traffic series collected from the urban road network in Beijing. Experimental results show that the urban traffic networks constructed by three traffic variables all indicate both small-world and scale-free characteristics. Compared with the results of PageRank algorithm, GWPA is proved to be valid in evaluating the importance of segments and identifying the important segments with small degree.

Spatial Correlation Characterization of a Full Dimension Massive MIMO System

KAUST Repository

Nadeem, Qurrat-Ul-Ain

2017-02-07

Elevation beamforming and Full Dimension MIMO (FD-MIMO) are currently active areas of research and standardization in 3GPP LTE-Advanced. FD-MIMO utilizes an active antenna array system (AAS), that provides the ability of adaptive electronic beam control over the elevation dimension, resulting in a better system performance as compared to the conventional 2D MIMO systems. FD-MIMO is more advantageous when amalgamated with massive MIMO systems, in that it exploits the additional degrees of freedom offered by a large number of antennas in the elevation. To facilitate the evaluation of these systems, a large effort in 3D channel modeling is needed. This paper aims at providing a summary of the recent 3GPP activity around 3D channel modeling. The 3GPP proposed approach to model antenna radiation pattern is compared with the ITU approach. A closed-form expression is then worked out for the spatial correlation function (SCF) for channels constituted by individual antenna elements in the array by exploiting results on spherical harmonics and Legendre polynomials. The proposed expression can be used to obtain correlation coefficients for any arbitrary 3D propagation environment. Simulation results corroborate and study the derived spatial correlation expression. The results are directly applicable to the analysis of future 5G 3D massive MIMO systems.

Modelling the distribution of fish accounting for spatial correlation and overdispersion

DEFF Research Database (Denmark)

Lewy, Peter; Kristensen, Kasper

2009-01-01

correlation between observations. It is therefore possible to predict and interpolate unobserved densities at any location in the area. This is important for obtaining unbiased estimates of stock concentration and other measures depending on the distribution in the entire area. Results show that the spatial...

Integrated corridor management : implementation guide and lessons learned (final report version 2.0).

Science.gov (United States)

2015-09-01

This implementation guide is intended for use by adopters of integrated corridor management (ICM) approaches and strategies to address congestion and travel time reliability issues within specific travel corridors. It introduces the topic of ICM and ...

Nitrogen retention in river corridors: European perspective

Energy Technology Data Exchange (ETDEWEB)

Haycock, N [Dept. of Agriculture and Water Management, Silsoe College, Cranfield Institute of Technology (United Kingdom); Pinay, G [CERR/CNRS, Toulouse (France); Walker, Charles [SBEG, Inst. of Ecology, Lund Univ. (Sweden)

1993-01-01

The problem of nitrogen pollution in European surface- and groundwaters has become a focus of recent European and Scandinavian directives, with legislation calling for a 50% reduction of N losses by the years 1995 and 2000, respectively. This paper provides a conceptual framework upon which management strategies to reduce losses of diffuse nitrogen pollution to surface waters may be based. The control of nitrogen pollution may take place through an increase in the complexity of the landscape, not throughout the catchment area, but rather in specific zones, the river corridor in particular. Within river corridors, riparian areas have been recognized globally for their value as nutrient removal ''buffer systems''. Studies have identified vegetation uptake and microbial denitrification as the primary mechanisms responsible for N removal in these systems. For these processes to function optimally on an annual basis, both vegetation and water regime must be managed. The establishment and management of riparian buffer zones in suitable places within river corridors, will provide a stable and sustainable water-protection function. This will complement future nitrogen input control strategies, needed for both the long-term protection of groundwater and surface waters in Europe as a whole, and for the proposed 50% reduction in nitrogen loading to the Baltic and North Sea coastal waters by the turn of the century. 52 refs, 5 figs

Attractive Mobile Corridors - The Power of Light Rail Infrastructures

DEFF Research Database (Denmark)

Olesen, Mette; Lassen, Claus

2013-01-01

Light rail is a popular tool in urban development strategies in many European cities. One argument for choosing a rail-based solution is that it signals stability to investors and will attract development and investments in the corridor. The choice of corridor in the various light rail cities...... and redistributes urban space. Furthermore light rail is not only a physical infrastructure but also an infrastructure of power that is carefully planned and designed creating both mental and physical patterns of mobilities and immobilities. Hence it is important to underline that mobility systems, such as light...

How green are the TEN-T core network corridors?

DEFF Research Database (Denmark)

Panagakos, George; Psaraftis, Harilaos N.

defining this concept, identified the characteristics that distinguish a green corridor from an otherwise efficient one. The main thesis of this paper is that the „core network corridors‟ of the new TEN-T guidelines exhibit all these qualities and the vision of a green corridor network in Europe is close...... to reality. To support this thesis, and in continuation of the work of SuperGreen, the paper examines the proposed new „guidelines‟ for the development of the TEN-T after presenting a brief history of transport network development in Europe....

Transport Improvements and Impacts on Land Use Dynamics and Economic Development: Evidence for the Dublin-Belfast Corridor

DEFF Research Database (Denmark)

Williams, Brendan; Foley, Walter; Shahumyan, Harutyun

2016-01-01

Transport infrastructure improvements are frequently dealt without adequate consideration of land use management issues. Theoretically this would not appear to be consistent with urban economic theory which prioritises the critical role that transportation plays in all urban economic spatial land...... and planning systems need to be better aligned. In this paper we examine policy evolution and recent policy outcomes and trends in the Belfast-Dublin corridor in light of the major infrastructure investment which occurred based upon official data within the time period mid 1990s (when many investments...... commenced) to 2012 (completion and use of those investments). It will investigate recent trends in terms of emerging economic development patterns since the creation of the M1 motorway and improved rail links. The research will incorporate spatial analytic modelling of current and future development trends...

Effect of spatially correlated noise on stochastic synchronization in globally coupled FitzHugh-Nagumo neuron systems

Directory of Open Access Journals (Sweden)

Yange Shao

2014-01-01

Full Text Available The phenomenon of stochastic synchronization in globally coupled FitzHugh-Nagumo (FHN neuron system subjected to spatially correlated Gaussian noise is investigated based on dynamical mean-field approximation (DMA and direct simulation (DS. Results from DMA are in good quantitative or qualitative agreement with those from DS for weak noise intensity and larger system size. Whether the consisting single FHN neuron is staying at the resting state, subthreshold oscillatory regime, or the spiking state, our investigation shows that the synchronization ratio of the globally coupled system becomes higher as the noise correlation coefficient increases, and thus we conclude that spatial correlation has an active effect on stochastic synchronization, and the neurons can achieve complete synchronization in the sense of statistics when the noise correlation coefficient tends to one. Our investigation also discloses that the noise spatial correlation plays the same beneficial role as the global coupling strength in enhancing stochastic synchronization in the ensemble. The result might be useful in understanding the information coding mechanism in neural systems.

Managing the spatial properties and photon correlations in squeezed non-classical twisted light

Science.gov (United States)

Zakharov, R. V.; Tikhonova, O. V.

2018-05-01

Spatial photon correlations and mode content of the squeezed vacuum light generated in a system of two separated nonlinear crystals is investigated. The contribution of both the polar and azimuthal modes with non-zero orbital angular momentum is analyzed. The control and engineering of the spatial properties and degree of entanglement of the non-classical squeezed light by changing the distance between crystals and pump parameters is demonstrated. Methods for amplification of certain spatial modes and managing the output mode content and intensity profile of quantum twisted light are suggested.

Ergodic channel capacity of spatial correlated multiple-input multiple-output free space optical links using multipulse pulse-position modulation

Science.gov (United States)

Wang, Huiqin; Wang, Xue; Cao, Minghua

2017-02-01

The spatial correlation extensively exists in the multiple-input multiple-output (MIMO) free space optical (FSO) communication systems due to the channel fading and the antenna space limitation. Wilkinson's method was utilized to investigate the impact of spatial correlation on the MIMO FSO communication system employing multipulse pulse-position modulation. Simulation results show that the existence of spatial correlation reduces the ergodic channel capacity, and the reception diversity is more competent to resist this kind of performance degradation.

Spatial correlation of the ionsphere total electron content at the equatorial anomaly crest

International Nuclear Information System (INIS)

Huang, Y.

1984-01-01

The spatial correlation of the ionospheric total electron content (TEC) at the equatorial anomaly crest was studied by recording Faraday rotation angle of the ETS-II geostationary satellite at Lunping and Kaohsiung whose subionospheric points are located at 23.0 0 N, 121.0 0 N, and 20.9 0 N, 121.1 0 E, respectively, and are about 280 km apart. The results show that the spatial correlation of TEC at the equatorial crest region is smaller than that at other places. The day-to-day variabilities of TEC differences between two subionospheric points are quite large. The day-to-day variabilities of the fountain effect seem to play an important role

Transit space: The corridor Berlin–Moscow and German-Polish border to Poznan

Directory of Open Access Journals (Sweden)

Wilfried Hackenbroich

2004-01-01

Full Text Available Transit space is about the infrastructure investigations concerning the spatial order of the “corridor” Berlin–Moscow and the most dynamic part of the “corridor” from the German-Polish Border to Poznan. It is based on the research conducted during the Bauhaus Kolleg V, “Transit Spaces: Transitional Cities in Eastern Europe” 2003/04 in the Bauhaus Dessau Foundation. The corridor between Berlin and Moscow is one example for a new spatial order within the postsocialism of Eastern Europe, and the flow of capital and goods, migrant streams, the EU expansion, communication networks and the development of the infrastructure holding it together. Transit economies and multilayered new allocation policies result from the shifting of the EU to the East, and cause new spatial structures and differentiations. Beyond the national borders, new invisible but effective spatial barriers and frontiers have emerged. The case studies, along the two lane transit road from the German Polish border to Poznan reveal an intense sequence of service stations, 24 hour bars, night clubs, restaurants and hotels. Complex service stations were built and placed – like pearls on a chain – along new goods traffic axes at so far undeveloped territories. They are nodes in the network of a global flow of goods, information and products of daily use. This article investigates the conditions and prospects of this new area within the European development.

Green corridors and their possible impact on the European supply chain

DEFF Research Database (Denmark)

Panagakos, George; Psaraftis, Harilaos N.; Holte, Even Ambros

2015-01-01

The purpose of this chapter is to present the concept of green corridors and analyse their possible impact on the supply chain. The basis of this material is work conducted in the context of the EU SuperGreen project and therefore the geographical setting of the chapter is Europe. The general...... objective of the SuperGreen project has been to support the development of sustainable transport networks by fulfilling requirements covering environmental, technical, economic, social and spatial planning aspects. The chapter deals only with surface freight transport, including maritime transport, noting...... employed in Europe, and describes the performance monitoring methodology developed by SuperGreen. The deep sea service linking China to Europe is compared to the trans-Siberian rail link between Beijing and Duisburg as an example. Finally, the new transport infrastructure policy of the European Union...

The significance of the Danube ecological corridor in the proceedings of implementing ecological networks in Serbia

Directory of Open Access Journals (Sweden)

Filipović Dejan

2015-01-01

Full Text Available With the modern processes for exploiting land people have altered the original appearance of areas and created cultural environments. The remaining natural environments, whether protected or not, take up a relatively small portion of space and represent isolated islands which in itself can not be sufficient for the preservation of biodiversity or for the fulfillment of national, regional or international goals and commitments related to their preservation. In order to secure the preservation of biodiversity, the strengthening of integrity and the natural processes, such as animal migrations, succession of vegetation and evolution processes, the communication between natural habitats is imperative. Ecological corridors, as integral elements of ecological networks, ensure the preservation of vital ecological interactions by providing a connection between different habitats or areas. Depending on a range of factors, from the fulfillment of demands of different species to the connecting of regions, corridors of local, sub-regional, regional and international importance are identified. The Danube ecological corridor is one of the most significant corridors of international importance which encompasses a large number of habitats which are part of the natural watercourse of the corridor. There are numerous protected areas in the Danube coastal area on Serbia's territory which present themselves as central areas for forming the ecological network, such as: Gornje Podunavlje, Karađorđevo, Fruška Gora, Titelski Breg hill, Kovalski rit marsh, Dunavski loess bluffs, the Sava mouth, Labudovo okno, Deliblato sands, Đerdap and Mala Vrbica. The diverse and mosaic vegetation of the floodplain, as well as the consistency of the protected areas within the Danube corridor have a direct influence on the quality and functionality of this corridor. The goal of this paper is to show the significance of the Danube ecological corridor in the process of implementing

'Level-level correlation and absorption in nuclear reactions'

International Nuclear Information System (INIS)

Hussein, M.S.

Level-level correlation (LLC) in nuclear reactions is discussed in general and it is shown that in the presence of LLC, N sub(μ) = Σ/g μa/ 2 > divided by gamma μ T tilde, where T tilde is the average absorption in the eigen channels [pt

Nearest neighbor imputation using spatial-temporal correlations in wireless sensor networks.

Science.gov (United States)

Li, YuanYuan; Parker, Lynne E

2014-01-01

Missing data is common in Wireless Sensor Networks (WSNs), especially with multi-hop communications. There are many reasons for this phenomenon, such as unstable wireless communications, synchronization issues, and unreliable sensors. Unfortunately, missing data creates a number of problems for WSNs. First, since most sensor nodes in the network are battery-powered, it is too expensive to have the nodes retransmit missing data across the network. Data re-transmission may also cause time delays when detecting abnormal changes in an environment. Furthermore, localized reasoning techniques on sensor nodes (such as machine learning algorithms to classify states of the environment) are generally not robust enough to handle missing data. Since sensor data collected by a WSN is generally correlated in time and space, we illustrate how replacing missing sensor values with spatially and temporally correlated sensor values can significantly improve the network's performance. However, our studies show that it is important to determine which nodes are spatially and temporally correlated with each other. Simple techniques based on Euclidean distance are not sufficient for complex environmental deployments. Thus, we have developed a novel Nearest Neighbor (NN) imputation method that estimates missing data in WSNs by learning spatial and temporal correlations between sensor nodes. To improve the search time, we utilize a k d-tree data structure, which is a non-parametric, data-driven binary search tree. Instead of using traditional mean and variance of each dimension for k d-tree construction, and Euclidean distance for k d-tree search, we use weighted variances and weighted Euclidean distances based on measured percentages of missing data. We have evaluated this approach through experiments on sensor data from a volcano dataset collected by a network of Crossbow motes, as well as experiments using sensor data from a highway traffic monitoring application. Our experimental

Spatial- and Time-Correlated Detection of Fission Fragments

Directory of Open Access Journals (Sweden)

Platkevic M.

2012-02-01

Full Text Available With the goal to measure angular correlations of fission fragments in rare fission decay (e.g. ternary and quaternary fission, a multi-detector coincidence system based on two and up to four position sensitive pixel detectors Timepix has been built. In addition to the high granularity, wide dynamic range and per pixel signal threshold, these devices are equipped with per pixel energy and time sensitivity providing more information (position, energy, time, enhances particle-type identification and selectivity of event-by-event detection. Operation of the device with the integrated USB 2.0 based readout interface FITPix and the control and data acquisition software tool Pixelman enables online visualization and flexible/adjustable operation for a different type of experiments. Spatially correlated fission fragments can be thus registered in coincidence. Similarly triggered measurements are performed using an integrated spectrometric module with analogue signal chain electronics. The current status of development together with demonstration of the technique with a 252Cf source is presented.

Africa's Oesophageal Cancer Corridor: Geographic Variations in Incidence Correlate with Certain Micronutrient Deficiencies.

Directory of Open Access Journals (Sweden)

Torin Schaafsma

Full Text Available The aetiology of Africa's easterly-lying corridor of squamous cell oesophageal cancer is poorly understood. Micronutrient deficiencies have been implicated in this cancer in other areas of the world, but their role in Africa is unclear. Without prospective cohorts, timely insights can instead be gained through ecological studies.Across Africa we assessed associations between a country's oesophageal cancer incidence rate and food balance sheet-derived estimates of mean national dietary supplies of 7 nutrients: calcium (Ca, copper (Cu, iron (Fe, iodine (I, magnesium (Mg, selenium (Se and zinc (Zn. We included 32 countries which had estimates of dietary nutrient supplies and of better-quality GLOBCAN 2012 cancer incidence rates. Bayesian hierarchical Poisson lognormal models were used to estimate incidence rate ratios for oesophageal cancer associated with each nutrient, adjusted for age, gender, energy intake, phytate, smoking and alcohol consumption, as well as their 95% posterior credible intervals (CI. Adult dietary deficiencies were quantified using an estimated average requirements (EAR cut-point approach.Adjusted incidence rate ratios for oesophageal cancer associated with a doubling of mean nutrient supply were: for Fe 0.49 (95% CI: 0.29-0.82; Mg 0.58 (0.31-1.08; Se 0.40 (0.18-0.90; and Zn 0.29 (0.11-0.74. There were no associations with Ca, Cu and I. Mean national nutrient supplies exceeded adult EARs for Mg and Fe in most countries. For Se, mean supplies were less than EARs (both sexes in 7 of the 10 highest oesophageal cancer ranking countries, compared to 23% of remaining countries. For Zn, mean supplies were less than the male EARs in 8 of these 10 highest ranking countries compared to in 36% of other countries.Ecological associations are consistent with the potential role of Se and/or Zn deficiencies in squamous cell oesophageal cancer in Africa. Individual-level analytical studies are needed to elucidate their causal role in this

Dynamic network expansion, contraction, and connectivity in the river corridor of mountain stream network

Science.gov (United States)

Ward, A. S.; Schmadel, N.; Wondzell, S. M.

2017-12-01

River networks are broadly recognized to expand and contract in response to hydrologic forcing. Additionally, the individual controls on river corridor dynamics of hydrologic forcing and geologic setting are well recognized. However, we currently lack tools to integrate our understanding of process dynamics in the river corridor and make predictions at the scale of river networks. In this study, we develop a perceptual model of the river corridor in mountain river networks, translate this into a reduced-complexity mechanistic model, and implement the model in a well-studied headwater catchment. We found that the river network was most sensitive to hydrologic dynamics under the lowest discharges (Qgauge managers of water resources who need to estimate connectivity and flow initiation location along the river corridor over broad, unstudied catchments.

I-15 integrated corridor management : system requirements.

Science.gov (United States)

2011-07-01

This document is intended as a listing and discussion of the Requirements for the I-15 Integrated Corridor Management System : (ICMS) Demonstration Project in San Diego. This document describes what the system is to do (the functional requirements), ...

RISK CORRIDORS AND REINSURANCE IN HEALTH INSURANCE MARKETPLACES: Insurance for Insurers

OpenAIRE

LAYTON, TIMOTHY J.; MCGUIRE, THOMAS G.; SINAIKO, ANNA D.

2016-01-01

In order to encourage entry and lower prices, most regulated markets for health insurance include policies that seek to reduce the uncertainty faced by insurers. In addition to risk adjustment of premiums paid to plans, the Health Insurance Marketplaces established by the Affordable Care Act implement reinsurance and risk corridors. Reinsurance limits insurer costs associated with specific individuals, while risk corridors protect against aggregate losses. Both tighten the insurer's distribut...

Assessing Anthropogenic Influence and Edge Effect Influence on Forested Riparian Buffer Spatial Configuration and Structure: An Example Using Lidar Remote Sensing Methods

Science.gov (United States)

Wasser, L. A.; Chasmer, L. E.

2012-12-01

Forested riparian buffers (FRB) perform numerous critical ecosystem services. However, globally, FRB spatial configuration and structure have been modified by anthropogenic development resulting in widespread ecological degradation as seen in the Gulf of Mexico and the Chesapeake Bay. Riparian corridors within developed areas are particularly vulnerable to disturbance given two edges - the naturally occurring stream edge and the matrix edge. Increased edge length predisposes riparian vegetation to "edge effects", characterized by modified physical and environmental conditions at the interface between the forested buffer and the adjacent landuse, or matrix and forest fragment degradation. The magnitude and distance of edge influence may be further influenced by adjacent landuse type and the width of the buffer corridor at any given location. There is a need to quantify riparian buffer spatial configuration and structure over broad geographic extents and within multiple riparian systems in support of ecologically sound management and landuse decisions. This study thus assesses the influence of varying landuse types (agriculture, suburban development and undeveloped) on forested riparian buffer 3-dimensional structure and spatial configuration using high resolution Light Detection and Ranging (LiDAR) data collected within a headwater watershed. Few studies have assessed riparian buffer structure and width contiguously for an entire watershed, an integral component of watershed planning and restoration efforts such as those conducted throughout the Chesapeake Bay. The objectives of the study are to 1) quantify differences in vegetation structure at the stream and matrix influenced riparian buffer edges, compared to the forested interior and 2) assess continuous patterns of changes in vegetation structure throughout the buffer corridor beginning at the matrix edge and ending at the stream within buffers a) of varying width and b) that are adjacent to varying landuse

Transportation policy and governance in the northeast corridor : an overview of major public agencies.

Science.gov (United States)

2009-08-01

One of the most consistent topics of discussion about the Northeast Corridor (hereafter : NEC or the Corridor), particularly the central portion between Boston and Washington, : D.C., is the viability and efficiency of its transportation ...

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement

Directory of Open Access Journals (Sweden)

Newman Justin T

2011-05-01

Full Text Available Abstract Background Percutaneous sacro-iliac (SI screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Methods Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Results Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%. The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069. In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99 having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal, compared to male counterparts (n = 245; P P = 0.06, implying S2 as a safe surgical corridor of choice in patients with sacral dysmorphia. Conclusions These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients

The level of spatial orientation of basketball players aged 14 years

Directory of Open Access Journals (Sweden)

Pomeschikova I. P.

2012-03-01

Full Text Available The article studies the performance level of the spatial orientation of the basketball teams' pre-basic training, which was determined by standard methods. The study involved 12 athletes for 14 years with four years basketball. Teacher testing conducted to determine the allowed level of basketball and to determine the spatial relationship between the rates of the various manifestations of this ability. The level of spatial orientation of sportsmen evaluated according to the 8 test, methodology suggested V.A. Romanenko, L.P. Sergienko, V.I. Lyakh.

Correlation of spatial climate/weather maps and the advantages of using the Mahalanobis metric in predictions

OpenAIRE

Stephenson, D. B.

2011-01-01

he skill in predicting spatially varying weather/climate maps depends on the definition of the measure of similarity between the maps. Under the justifiable approximation that the anomaly maps are distributed multinormally, it is shown analytically that the choice of weighting metric, used in defining the anomaly correlation between spatial maps, can change the resulting probability distribution of the correlation coefficient. The estimate of the numbers of degrees of freedom based on the var...

Wild felid species richness affected by a corridor in the Lacandona forest, Mexico

Directory of Open Access Journals (Sweden)

Gil–Fernández, M.

2017-02-01

Full Text Available Wild felids are one of the most vulnerable species due to habitat loss caused by fragmentation of ecosystems. We analyzed the effect of a structural corridor, defined as a strip of vegetation connecting two habitat patches, on the richness and habitat occupancy of felids on three sites in Marqués de Comillas, Chiapas, one with two isolated forest patches, the second with a structural corridor, and the third inside the Montes Azules Biosphere Reserve. We found only two species (L. pardalis and H. yagouaroundi in the isolated forest patches, five species in the structural corridor, and four species inside the Reserve. The corridor did not significantly affect occupancy, but due to the low detection rates, further investigation is needed to rule out differences. Our results highlight the need to manage habitat connectivity in the remaining forests in order to preserve the felid community of Marqués de Comillas, Chiapas, México.

Louisiana Speaks Regional Vision Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_vision_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the primary and secondary transit corridors included in the Louisiana Speaks Regional Plan Vision. This network accommodates a...

3D spatially-adaptive canonical correlation analysis: Local and global methods.

Science.gov (United States)

Yang, Zhengshi; Zhuang, Xiaowei; Sreenivasan, Karthik; Mishra, Virendra; Curran, Tim; Byrd, Richard; Nandy, Rajesh; Cordes, Dietmar

2018-04-01

Local spatially-adaptive canonical correlation analysis (local CCA) with spatial constraints has been introduced to fMRI multivariate analysis for improved modeling of activation patterns. However, current algorithms require complicated spatial constraints that have only been applied to 2D local neighborhoods because the computational time would be exponentially increased if the same method is applied to 3D spatial neighborhoods. In this study, an efficient and accurate line search sequential quadratic programming (SQP) algorithm has been developed to efficiently solve the 3D local CCA problem with spatial constraints. In addition, a spatially-adaptive kernel CCA (KCCA) method is proposed to increase accuracy of fMRI activation maps. With oriented 3D spatial filters anisotropic shapes can be estimated during the KCCA analysis of fMRI time courses. These filters are orientation-adaptive leading to rotational invariance to better match arbitrary oriented fMRI activation patterns, resulting in improved sensitivity of activation detection while significantly reducing spatial blurring artifacts. The kernel method in its basic form does not require any spatial constraints and analyzes the whole-brain fMRI time series to construct an activation map. Finally, we have developed a penalized kernel CCA model that involves spatial low-pass filter constraints to increase the specificity of the method. The kernel CCA methods are compared with the standard univariate method and with two different local CCA methods that were solved by the SQP algorithm. Results show that SQP is the most efficient algorithm to solve the local constrained CCA problem, and the proposed kernel CCA methods outperformed univariate and local CCA methods in detecting activations for both simulated and real fMRI episodic memory data. Copyright © 2017 Elsevier Inc. All rights reserved.

Swift fox survey along Heartland Expressway Corridor.

Science.gov (United States)

2015-05-01

The swift fox (Vulpes velox) is a small canid classified as endangered within the : state of Nebraska. Future construction of the Heartland Expressway Corridor (HEC), a : 300 km road expansion project in the panhandle of the state, may impact the res...

The present condition and projection of construction of railway net of the Danube-Morava corridor

Directory of Open Access Journals (Sweden)

Vemić Mirčeta

2005-01-01

Full Text Available The railway net of the Danube-Morava corridor, together with the road net represent the central section of the Pan-European transport corridor X. According to the traffic and economic standards, the railway net represents the second main traffic direction of this corridor as the area-functioning system of the territory of Serbia. Main railway lines have favourable positions as they are located along prominent geographical features, namely river valleys thus enabling considerable flow of goods, passengers and information. The paper presents some characteristics of the present condition of the railway net, its functioning and safety, with certain ideas of its future construction and expected exploitation till 2015. Traffic infrastructure represents the initial factor of overall development of a state and its connection with the surrounding countries. It is considered to be of strategic importance for a country to built railway net. Improvement and additional construction of railway lines is of the greatest priority for the purpose of enlargement of overall mobility and quality of life of population, to make urban areas closer, to improve connections, functions efficiency and level of services of railway system, reduction of negative influence on other economic systems and human environment, better safety etc.

US-75 ICM system as-built design : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2015-05-01

This As-Built document for the US-75 Integrated Corridor Management (ICM) Program has been developed as part of the US Department of Transportation Integrated Corridor Management Initiative. The basic premise behind the ICM initiative is that indepen...

Siliguri: A Geopolitical Manoeuvre Corridor in the Eastern Himalayan Region for China and India

Directory of Open Access Journals (Sweden)

Hasan Yaser Malik

2015-12-01

Full Text Available Siliguri Corridor being part of Indian West Bengal is a diplomatic manoeuvre place located between Nepal, Bhutan, Bangladesh, India’s Seven Sister States and Chumbi Hills in the Eastern Himalayan Region. Being located at the crossroads and centrally situated between all the neighbouring countries the landlocked Siliguri has an especially economic and political value for the regional countries. The corridor being in close proximity to China and India’s Seven Sister States has added to the diplomatic mosaic of the Eastern Himalayan Region. The region consists of beautiful landscape, mountains and rivers which not only add to topographical diversity but also demographic mixture. Despite its geopolitical significance the area could not advance for not only being a northeastern border region but also for being a gateway to the Seven Sister States. Peripheral development of Siliguri Corridor is one of the reasons for illegal practices like smuggling and terrorism. In year 2002 Nepal, Bhutan and Bangladesh discussed a proposal to form a free trade corridor to simplify the goods transportation through Siliguri Corridor but no such pact could be concluded that would have avoided the activities like smuggling and terrorism mainly through economic and diplomatic ventures.

Prevalence of sacral dysmorphia in a prospective trauma population: Implications for a "safe" surgical corridor for sacro-iliac screw placement.

Science.gov (United States)

Hasenboehler, Erik A; Stahel, Philip F; Williams, Allison; Smith, Wade R; Newman, Justin T; Symonds, David L; Morgan, Steven J

2011-05-10

Percutaneous sacro-iliac (SI) screw fixation represents a widely used technique in the management of unstable posterior pelvic ring injuries and sacral fractures. The misplacement of SI-screws under fluoroscopic guidance represents a critical complication for these patients. This study was designed to determine the prevalence of sacral dysmorphia and the radiographic anatomy of surgical S1 and S2 corridors in a representative trauma population. Prospective observational cohort study on a consecutive series of 344 skeletally mature trauma patients of both genders enrolled between January 1, 2007, to September 30, 2007, at a single academic level 1 trauma center. Inclusion criteria included a pelvic CT scan as part of the initial diagnostic trauma work-up. The prevalence of sacral dysmorphia was determined by plain radiographic pelvic films and CT scan analysis. The anatomy of sacral corridors was analyzed on 3 mm reconstruction sections derived from multislice CT scan, in the axial, coronal, and sagittal plane. "Safe" potential surgical corridors at S1 and S2 were calculated based on these measurements. Radiographic evidence of sacral dysmorphia was detected in 49 patients (14.5%). The prevalence of sacral dysmorphia was not significantly different between male and female patients (12.2% vs. 19.2%; P = 0.069). In contrast, significant gender-related differences were detected with regard to radiographic analysis of surgical corridors for SI-screw placement, with female trauma patients (n = 99) having significantly narrower corridors at S1 and S2 in all evaluated planes (axial, coronal, sagittal), compared to male counterparts (n = 245; P dysmorphia. These findings emphasize a high prevalence of sacral dysmorphia in a representative trauma population and imply a higher risk of SI-screw misplacement in female patients. Preoperative planning for percutaneous SI-screw fixation for unstable pelvic and sacral fractures must include a detailed CT scan analysis to determine

Landuse Types within Channel Corridor and River Channel Morphology of River Ona, Ibadan, Nigeria

Directory of Open Access Journals (Sweden)

Olutoyin Fashae

2017-12-01

Full Text Available The importance of river a corridor warrants a well thought out and balanced management approach because it helps in improving or maintaining water quality, protecting wetlands, etc. Hence, this study seeks to identify major landuse types within the River Ona Corridor; examine the impact of these landuse types within the River Ona corridor on its channel morphology and understand the risk being posed by these landuse types. The study is designed by selecting two reaches of six times the average width from each of the four major landuse types that exist along the river corridor. This study revealed that along the downstream section of Eleyele Dam of River Ona, natural forest stabilizes river channel banks, thereby presenting a narrow and shallow width and depth respectively but the widest of all is found at the agricultural zones.

New York in the new world economy : the I-90 corridor study : final report

Science.gov (United States)

2002-12-01

The I-90 Corridor in upstate New York is a classic example of the de-industrialization of the Northeastern United States. With few exceptions, all counties along the corridor have experienced marked declined in manufacturing employment over the past ...

78 FR 73559 - Moose-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton...

Science.gov (United States)

2013-12-06

...-Wilson Corridor Comprehensive Management Plan, Environmental Impact Statement, Grand Teton National Park... is preparing a Comprehensive Management Plan and Environmental Impact Statement (EIS) for the Moose...; (2) distinguish the corridor's fundamental and other important resources and values; (3) clearly...

A Model for Assessing Pedestrian Corridors. Application to Vitoria-Gasteiz City (Spain

Directory of Open Access Journals (Sweden)

Javier Delso

2017-03-01

Full Text Available From a mobility perspective, walking is considered to be the most sustainable transport mode. One of the consequences of motor-oriented urban configuration on pedestrian mobility is urban fragmentation, which affects sustainability in cities. In this paper, we use a natural-based approach to landscape fragmentation and connectivity (inherited from landscape ecology for pedestrian mobility planning. Our aim is to design a useful methodology to identify priority pedestrian corridors, and to assess the effects of implementing barrier-free pedestrian corridors in the city. For this purpose, we developed a method that integrates Geographical Information Systems (GIS network analysis with kernel density methods, which are commonly used for designating habitat corridors. It was applied to Vitoria-Gasteiz (Spain. Pedestrian mobility was assessed by comparison of travel times between different scenarios. Results show that the implementation of pedestrian corridors reduces travel time by approximately 6%. Thus, an intervention in a small percentage of the city’s street network could considerably reduce pedestrian travel times. The proposed methodology is a useful tool for urban and transport planners to improve pedestrian mobility and manage motorised traffic.

The spatial characteristics and pollution levels of metals in urban street dust of Beijing, China

International Nuclear Information System (INIS)

Tang, Rongli; Ma, Keming; Zhang, Yuxin; Mao, Qizheng

2013-01-01

Highlights: ·We explored the pollution characters of metals in street dust of Beijing. ·Area-source pollution and point-source pollution exist simultaneously. ·We identified the spatial autocorrelation intensities and ranges of metals. ·Metal pollution anomalies were identified by cluster and outlier analyses. ·Urban activities strongly influence the distributions of metals. - Abstract: The components and concentrations of metals in street dust are indictors of environmental pollution. To explore the pollution levels of Cd, Cr, Cu, Mn, Ni and Pb in street dust and their spatial distribution characteristics, 220 dust samples were collected in a grid pattern from urban street surfaces in Beijing. Multivariate statistics and spatial analyses were adopted to investigate the associations between metals and to identify their pollution patterns. In comparison with the soil background values, elevated metal concentrations were found, except those for Mn and Ni. The results of the geo-accumulation index (I geo ) and the potential ecological risk index (Er i ) of the metals revealed the following orders: Cd > Cu > Cr > Pb > Ni > Mn and Cd > Cu > Pb > Cr > Ni. Levels of I geo ranging from 0 to 5 were found and about 80% of the samples were below the moderately polluted level. The Er i values of single elements were within the low ecological risk level in most sampling sites. Most of the metals in the street dust of Beijing were statistically significantly correlated. It is hard to clearly identify the sources of each metal in the street dust since local environments are very complex. Cadmium, Cu, Cr, Mn and Pb showed medium spatial autocorrelations within the sampling region. Similar spatial distribution patterns were observed for Cu, Cr and Pb, and these metals had relatively high spatial variabilities and were enriched in the center of the city with several peaks scattered in the suburbs. Metal pollution anomalies were identified by using cluster and outlier analyses

A spatial scan statistic for nonisotropic two-level risk cluster.

Science.gov (United States)

Li, Xiao-Zhou; Wang, Jin-Feng; Yang, Wei-Zhong; Li, Zhong-Jie; Lai, Sheng-Jie

2012-01-30

Spatial scan statistic methods are commonly used for geographical disease surveillance and cluster detection. The standard spatial scan statistic does not model any variability in the underlying risks of subregions belonging to a detected cluster. For a multilevel risk cluster, the isotonic spatial scan statistic could model a centralized high-risk kernel in the cluster. Because variations in disease risks are anisotropic owing to different social, economical, or transport factors, the real high-risk kernel will not necessarily take the central place in a whole cluster area. We propose a spatial scan statistic for a nonisotropic two-level risk cluster, which could be used to detect a whole cluster and a noncentralized high-risk kernel within the cluster simultaneously. The performance of the three methods was evaluated through an intensive simulation study. Our proposed nonisotropic two-level method showed better power and geographical precision with two-level risk cluster scenarios, especially for a noncentralized high-risk kernel. Our proposed method is illustrated using the hand-foot-mouth disease data in Pingdu City, Shandong, China in May 2009, compared with two other methods. In this practical study, the nonisotropic two-level method is the only way to precisely detect a high-risk area in a detected whole cluster. Copyright © 2011 John Wiley & Sons, Ltd.

Correlation of Salivary Glucose Level with Blood Glucose Level in Diabetes Mellitus

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Arati S. Panchbhai

2012-07-01

Full Text Available Objectives: There is alarming rise in number of people with diabetes mellitus over these years. If glucose in saliva is linked to glucose in blood it can be used to detect diabetes mellitus at an early stage. The present study is undertaken with the aim to assess the correlation of salivary glucose level with blood glucose level in people with diabetes mellitus. Material and Methods: For investigations, 2 sets of samples of people with diabetes and the age and sex matched non-diabetic subjects were recruited. The salivary glucose was analyzed in unstimulated whole saliva samples using glucose oxidase method. Pearson’s correlation coefficient test was applied to assess the correlation between salivary glucose level and blood glucose level. Results: The significant (P < 0.05 positive correlation of salivary glucose level and fasting blood glucose level was observed in people with uncontrolled diabetes in both the sets of samples.Conclusions: Although study suggests some potential for saliva as a marker in monitoring of diabetes mellitus, there are many aspects that need clarification before we reach to a conclusion.

Developing transit-oriented corridors: insights from Tokyo

NARCIS (Netherlands)

Chorus, P.; Bertolini, L.

2016-01-01

Various studies have pointed out that a successful integration of public transport and land use requires plans covering the entire metropolitan region that are consistent over a long period of time. The proposition that is explored in this article is that railway corridors can offer an effective

Panel data models with spatial correlation: Estimation theory and an empirical investigation of the United States wholesale gasoline industry

Science.gov (United States)

Kapoor, Mudit

The first part of my dissertation considers the estimation of a panel data model with error components that are both spatially and time-wise correlated. The dissertation combines widely used model for spatial correlation (Cliff and Ord (1973, 1981)) with the classical error component panel data model. I introduce generalizations of the generalized moments (GM) procedure suggested in Kelejian and Prucha (1999) for estimating the spatial autoregressive parameter in case of a single cross section. I then use those estimators to define feasible generalized least squares (GLS) procedures for the regression parameters. I give formal large sample results concerning the consistency of the proposed GM procedures, as well as the consistency and asymptotic normality of the proposed feasible GLS procedures. The new estimators remain computationally feasible even in large samples. The second part of my dissertation employs a Cliff-Ord-type model to empirically estimate the nature and extent of price competition in the US wholesale gasoline industry. I use data on average weekly wholesale gasoline price for 289 terminals (distribution facilities) in the US. Data on demand factors, cost factors and market structure that affect price are also used. I consider two time periods, a high demand period (August 1999) and a low demand period (January 2000). I find a high level of competition in prices between neighboring terminals. In particular, price in one terminal is significantly and positively correlated to the price of its neighboring terminal. Moreover, I find this to be much higher during the low demand period, as compared to the high demand period. In contrast to previous work, I include for each terminal the characteristics of the marginal customer by controlling for demand factors in the neighboring location. I find these demand factors to be important during period of high demand and insignificant during the low demand period. Furthermore, I have also considered spatial

Transitions in pedestrian fundamental diagrams of straight corridors and T-junctions

International Nuclear Information System (INIS)

Zhang, J; Klingsch, W; Schadschneider, A; Seyfried, A

2011-01-01

Many observations of pedestrian dynamics, including various self-organization phenomena, have been reproduced successfully by different models. But the empirical databases for quantitative calibration are still insufficient, e.g. the fundamental diagram as one of the most important relationships displays non-negligible differences among various studies. To improve this situation, experiments in straight corridors and T-junctions are performed. Four different measurement methods are defined to study their effects on the fundamental diagram. It is shown that they have minor influences for ρ −2 but only the Voronoi method is able to resolve the fine structure of the fundamental diagram. This enhanced measurement method permits us to observe the occurrence of a boundary-induced phase transition. For corridors of different widths we found that the specific flow concept works well for ρ −2 . Moreover, we illustrate the discrepancies between the fundamental diagrams of a T-junction and a straight corridor

Integrating occupancy modeling and interview data for corridor identification: A case study for jaguars in Nicaragua

Science.gov (United States)

Zeller, K.A.; Nijhawan, S.; Salom-Perez, R.; Potosme, S.H.; Hines, J.E.

2011-01-01

Corridors are critical elements in the long-term conservation of wide-ranging species like the jaguar (Panthera onca). Jaguar corridors across the range of the species were initially identified using a GIS-based least-cost corridor model. However, due to inherent errors in remotely sensed data and model uncertainties, these corridors warrant field verification before conservation efforts can begin. We developed a novel corridor assessment protocol based on interview data and site occupancy modeling. We divided our pilot study area, in southeastern Nicaragua, into 71, 6. ??. 6 km sampling units and conducted 160 structured interviews with local residents. Interviews were designed to collect data on jaguar and seven prey species so that detection/non-detection matrices could be constructed for each sampling unit. Jaguars were reportedly detected in 57% of the sampling units and had a detection probability of 28%. With the exception of white-lipped peccary, prey species were reportedly detected in 82-100% of the sampling units. Though the use of interview data may violate some assumptions of the occupancy modeling approach for determining 'proportion of area occupied', we countered these shortcomings through study design and interpreting the occupancy parameter, psi, as 'probability of habitat used'. Probability of habitat use was modeled for each target species using single state or multistate models. A combination of the estimated probabilities of habitat use for jaguar and prey was selected to identify the final jaguar corridor. This protocol provides an efficient field methodology for identifying corridors for easily-identifiable species, across large study areas comprised of unprotected, private lands. ?? 2010 Elsevier Ltd.

Composition and abundance of small mammal communities in forest fragments and vegetation corridors in Southern Minas Gerais, Brazil

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Andréa O. Mesquita

2012-09-01

Full Text Available Habitat fragmentation leads to isolation and reduce habitat areas, in addition to a series of negative effects on natural populations, affecting richness, abundance and distribution of animal species. In such a text, habitat corridors serve as an alternative for connectivity in fragmented landscapes, minimizing the effects of structural isolation of different habitat areas. This study evaluated the richness, composition and abundance of small mammal communities in forest fragments and in the relevant vegetation corridors that connect these fragments, located in Southern Minas Gerais, Southeastern Brazil. Ten sites were sampled (five forest fragments and five vegetation corridors using the capture-mark-recapture method, from April 2007-March 2008. A total sampling effort of 6 300 trapnights resulted in 656 captures of 249 individuals. Across the 10 sites sampled, 11 small mammal species were recorded. Multidimensional scaling (MDS ordinations and ANOSIM based on the composition of small mammal communities within the corridor and fragment revealed a qualitative difference between the two environments. Regarding abundance, there was no significant difference between corridors and fragments. In comparing mean values of abundance per species in each environment, only Cerradomys subflavus showed a significant difference, being more abundant in the corridor environment. Results suggest that the presence of several small mammal species in the corridor environment, in relatively high abundances, could indicate corridors use as habitat, though they might also facilitate and/or allow the movement of individuals using different habitat patches (fragments.

Establishment of a National ecological network to conserve biodiversity. Pros and cons of ecological corridors Establishment of a National ecological network to conserve biodiversity. Pros and cons of ecological corridors

Directory of Open Access Journals (Sweden)

Laurent Bergès, Philip Roche and Catherine Avon

2011-03-01

Full Text Available Ecological corridors are a fundamental element in the National ecological network approved by the Grenelle environmental agreement in order to reduce ecosystem damage caused by fragmentation of the natural habitat zones of species. How can their effectiveness be evaluated? This article sums up current knowledge on their pros and cons.Fragmentation of natural habitats is considered one of the main causes of biodiversity loss. One of the proposed solutions to limit the effects of fragmentation is to restore ecological connectivity by creating ecological corridors between zones containing natural habitats. The concept remains controversial among scientists, but now serves as the basis for one of the operational projects of the Grenelle environmental agreements in the form of the National ecological network. After examining the ecological concepts justifying the political goal and presenting the various ecological roles of corridors, we briefly discuss their overall advantages and disadvantages. Then, we look closely at the methodological difficulties in detecting a corridor effect. Finally, we recommend a close partnership between research and policy to design biodiversity monitoring and evaluation systems in the different land-management plans.

U.S.--Canada international mobility and trade corridor

Science.gov (United States)

2002-05-01

Public and private stakeholders in Washington State and British Columbia established the international mobility and trade corridor (IMTC) partnership. The IMTC is a coalition of over 60 U.S. and Canadian business and government entities whose mission...

Habitat suitability and movement corridors of grey wolf (Canis lupus) in Northern Pakistan

Science.gov (United States)

Kabir, Muhammad; Hameed, Shoaib; Ali, Hussain; Bosso, Luciano; Din, Jaffar Ud; Bischof, Richard; Redpath, Steve

2017-01-01

Habitat suitability models are useful to understand species distribution and to guide management and conservation strategies. The grey wolf (Canis lupus) has been extirpated from most of its historic range in Pakistan primarily due to its impact on livestock and livelihoods. We used non-invasive survey data from camera traps and genetic sampling to develop a habitat suitability model for C. lupus in northern Pakistan and to explore the extent of connectivity among populations. We detected suitable habitat of grey wolf using a maximum entropy approach (Maxent ver. 3.4.0) and identified suitable movement corridors using the Circuitscape 4.0 tool. Our model showed high levels of predictive performances, as seen from the values of area under curve (0.971±0.002) and true skill statistics (0.886±0.021). The main predictors for habitat suitability for C. lupus were distances to road, mean temperature of the wettest quarter and distance to river. The model predicted ca. 23,129 km2 of suitable areas for wolf in Pakistan, with much of suitable habitat in remote and inaccessible areas that appeared to be well connected through vulnerable movement corridors. These movement corridors suggest that potentially the wolf range can expand in Pakistan’s Northern Areas. However, managing protected areas with stringent restrictions is challenging in northern Pakistan, in part due to heavy dependence of people on natural resources. The habitat suitability map provided by this study can inform future management strategies by helping authorities to identify key conservation areas. PMID:29121089

Spatial Decomposition of Translational Water–Water Correlation Entropy in Binding Pockets

Science.gov (United States)

2015-01-01

A number of computational tools available today compute the thermodynamic properties of water at surfaces and in binding pockets by using inhomogeneous solvation theory (IST) to analyze explicit-solvent simulations. Such methods enable qualitative spatial mappings of both energy and entropy around a solute of interest and can also be applied quantitatively. However, the entropy estimates of existing methods have, to date, been almost entirely limited to the first-order terms in the IST’s entropy expansion. These first-order terms account for localization and orientation of water molecules in the field of the solute but not for the modification of water–water correlations by the solute. Here, we present an extension of the Grid Inhomogeneous Solvation Theory (GIST) approach which accounts for water–water translational correlations. The method involves rewriting the two-point density of water in terms of a conditional density and utilizes the efficient nearest-neighbor entropy estimation approach. Spatial maps of this second order term, for water in and around the synthetic host cucurbit[7]uril and in the binding pocket of the enzyme Factor Xa, reveal mainly negative contributions, indicating solute-induced water–water correlations relative to bulk water; particularly strong signals are obtained for sites at the entrances of cavities or pockets. This second-order term thus enters with the same, negative, sign as the first order translational and orientational terms. Numerical and convergence properties of the methodology are examined. PMID:26636620

Mapping urban porosity and roughness characteristics as a mean of defining urban ventilation corridors

Science.gov (United States)

Wicht, Marzena; Wicht, Andreas; Osińska-Skotak, Katarzyna

2017-10-01

Cities can be characterized with the roughest aerodynamic boundaries, which results in the enhanced turbulent motion and increased drag effect. This leads to reduced wind speeds and directly increases negative effects of living within urban areas. Urban Heat Island, decreased air quality or densely built-up residential/industrial areas occur in many cities, both in temperate and tropical regions, and are included in these negative effects. This case study investigates Warsaw, the capital of Poland, representing a dense, urban environment, located in the temperate zone. It suffers from immense air pollution levels, as well as Urban Heat Island, and the local government is seeking ways to resolve these issues. Among many mitigation techniques, air restoration and exchange system were suggested as appropriate measures, as they address many of the aforementioned issues. The essential elements of such system are ventilation corridors. This paper describes mapping these corridors utilizing the morphometric methods of urban roughness aided by remote sensing data. We focus especially on the terrain topology and texture of single elements, including high vegetation canopy layer. This study considers DSM and different porosity of obstacles, deriving a new outlook at the morphometric methods as a way to improve them. The mapped areas of low roughness characteristics might be appointed as ventilation corridors and play a crucial role in air restoration and exchange system. They may also be included in further planning processes by the local government as preservation areas.

Quantum metrology subject to spatially correlated Markovian noise: restoring the Heisenberg limit

International Nuclear Information System (INIS)

Jeske, Jan; Cole, Jared H; Huelga, Susana F

2014-01-01

Environmental noise can hinder the metrological capabilities of entangled states. While the use of entanglement allows for Heisenberg-limited resolution, the largest permitted by quantum mechanics, deviations from strictly unitary dynamics quickly restore the standard scaling dictated by the central limit theorem. Product and maximally entangled states become asymptotically equivalent when the noisy evolution is both local and strictly Markovian. However, temporal correlations in the noise have been shown to lift this equivalence while fully (spatially) correlated noise allows for the identification of decoherence-free subspaces. Here we analyze precision limits in the presence of noise with finite correlation length and show that there exist robust entangled state preparations which display persistent Heisenberg scaling despite the environmental decoherence, even for small correlation length. Our results emphasize the relevance of noise correlations in the study of quantum advantage and could be relevant beyond metrological applications. (paper)

Considering built environment and spatial correlation in modeling pedestrian injury severity.

Science.gov (United States)

Prato, Carlo G; Kaplan, Sigal; Patrier, Alexandre; Rasmussen, Thomas K

2018-01-02

This study looks at mitigating and aggravating factors that are associated with the injury severity of pedestrians when they have crashes with another road user and overcomes existing limitations in the literature by focusing attention on the built environment and considering spatial correlation across crashes. Reports for 6,539 pedestrian crashes occurred in Denmark between 2006 and 2015 were merged with geographic information system resources containing detailed information about the built environment and exposure at the crash locations. A linearized spatial logit model estimated the probability of pedestrians sustaining a severe or fatal injury conditional on the occurrence of a crash with another road user. This study confirms previous findings about older pedestrians and intoxicated pedestrians being the most vulnerable road users and crashes with heavy vehicles and in roads with higher speed limits being related to the most severe outcomes. This study provides novel perspectives by showing positive spatial correlations of crashes with the same severity outcomes and emphasizing the role of the built environment in the proximity of the crash. This study emphasizes the need for thinking about traffic calming measures, illumination solutions, road maintenance programs, and speed limit reductions. Moreover, this study emphasizes the role of the built environment, because shopping areas, residential areas, and walking traffic density are positively related to a reduction in pedestrian injury severity. Often, these areas have in common a larger pedestrian mass that is more likely to make other road users more aware and attentive, whereas the same does not seem to apply to areas with lower pedestrian density.

The n-level spectral correlations for chaotic systems

International Nuclear Information System (INIS)

Nagao, Taro; Mueller, Sebastian

2009-01-01

We study the n-level spectral correlation functions of classically chaotic quantum systems without time-reversal symmetry. According to Bohigas, Giannoni and Schmit's universality conjecture, it is expected that the correlation functions are in agreement with the prediction of the circular unitary ensemble (CUE) of random matrices. A semiclassical resummation formalism allows us to express the correlation functions as sums over pseudo-orbits. Using an extended version of the diagonal approximation on the pseudo-orbit sums, we derive the n-level correlation functions identical to the n x n determinantal correlation functions of the CUE.

A spatial database of bedding attitudes to accompany Geologic map of the greater Denver area, Front Range Urban Corridor, Colorado

Science.gov (United States)

Trimble, Donald E.; Machette, Michael N.; Brandt, Theodore R.; Moore, David W.; Murray, Kyle E.

2003-01-01

This digital map shows bedding attitude symbols display over the geographic extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette 1973-1977 and published in 1979 (U.S. Geological Survey Map I-856-H) under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999), was digitized under the USGS Front Range Infrastructure Resources Project (see cross-reference). In general, the mountainous areas in the west part of the map exhibit various igneous and metamorphic bedrock units of Precambrian age, major faults, and fault brecciation zones at the east margin (5-20 km wide) of the Front Range. The eastern and central parts of the map (Colorado Piedmont) depict a mantle of unconsolidated deposits of Quaternary age and interspersed outcroppings of Cretaceous or Tertiary-Cretaceous sedimentary bedrock. The Quaternary mantle is comprised of eolian deposits (quartz sand and silt), alluvium (gravel, sand, and silt of variable composition), colluvium, and few landslides. At the mountain front, north-trending, dipping Paleozoic and Mesozoic sandstone, shale, and limestone bedrock formations form hogbacks and intervening valleys.

Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: Implications for resilience

Science.gov (United States)

Gothe, Emma; Sandin, Leonard; Allen, Craig R.; Angeler, David G.

2014-01-01

The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

Attention to Hierarchical Level Influences Attentional Selection of Spatial Scale

Science.gov (United States)

Flevaris, Anastasia V.; Bentin, Shlomo; Robertson, Lynn C.

2011-01-01

Ample evidence suggests that global perception may involve low spatial frequency (LSF) processing and that local perception may involve high spatial frequency (HSF) processing (Shulman, Sullivan, Gish, & Sakoda, 1986; Shulman & Wilson, 1987; Robertson, 1996). It is debated whether SF selection is a low-level mechanism associating global…

Linking Spatial Structure and Community-Level Biotic Interactions through Cooccurrence and Time Series Modeling of the Human Intestinal Microbiota.

Science.gov (United States)

de Muinck, Eric J; Lundin, Knut E A; Trosvik, Pål

2017-01-01

The gastrointestinal (GI) microbiome is a densely populated ecosystem where dynamics are determined by interactions between microbial community members, as well as host factors. The spatial organization of this system is thought to be important in human health, yet this aspect of our resident microbiome is still poorly understood. In this study, we report significant spatial structure of the GI microbiota, and we identify general categories of spatial patterning in the distribution of microbial taxa along a healthy human GI tract. We further estimate the biotic interaction structure in the GI microbiota, both through time series and cooccurrence modeling of microbial community data derived from a large number of sequentially collected fecal samples. Comparison of these two approaches showed that species pairs involved in significant negative interactions had strong positive contemporaneous correlations and vice versa, while for species pairs without significant interactions, contemporaneous correlations were distributed around zero. We observed similar patterns when comparing these models to the spatial correlations between taxa identified in the adherent microbiota. This suggests that colocalization of microbial taxon pairs, and thus the spatial organization of the GI microbiota, is driven, at least in part, by direct or indirect biotic interactions. Thus, our study can provide a basis for an ecological interpretation of the biogeography of the human gut. IMPORTANCE The human gut microbiome is the subject of intense study due to its importance in health and disease. The majority of these studies have been based on the analysis of feces. However, little is known about how the microbial composition in fecal samples relates to the spatial distribution of microbial taxa along the gastrointestinal tract. By characterizing the microbial content both in intestinal tissue samples and in fecal samples obtained daily, we provide a conceptual framework for how the spatial

A Strategic Market Analysis of the Open Market Corridor

National Research Council Canada - National Science Library

Clark

2003-01-01

... and an overall marketing strategy for the Open Market Corridor. Through comprehensive literature review and information gathering a focused analysis of a specific potential customer Naval Supply Systems Command (NAVSUP...

Road-corridor planning in the EIA procedure in Spain. A review of case studies

Energy Technology Data Exchange (ETDEWEB)

Loro, Manuel, E-mail: manuel.loro@upm.es [Department of Urban and Regional Planning and Environment, Civil Engineering School, Universidad Politécnica de Madrid, Prof. Aranguren s/n, 28040 Madrid (Spain); Transport Research Centre (TRANSyT-UPM) Universidad Politécnica de Madrid, ETSI Caminos, Canales y Puertos, Prof. Aranguren s/n, 28040 Madrid (Spain); Centro de investigación del transporte, TRANSyT-UPM, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Prof. Aranguren s/n, 28040 Madrid (Spain); Arce, Rosa M., E-mail: rosa.arce.ruiz@upm.es [Department of Urban and Regional Planning and Environment, Civil Engineering School, Universidad Politécnica de Madrid, Prof. Aranguren s/n, 28040 Madrid (Spain); Transport Research Centre (TRANSyT-UPM) Universidad Politécnica de Madrid, ETSI Caminos, Canales y Puertos, Prof. Aranguren s/n, 28040 Madrid (Spain); Centro de investigación del transporte, TRANSyT-UPM, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Prof. Aranguren s/n, 28040 Madrid (Spain); Ortega, Emilio, E-mail: e.ortega@upm.es [Transport Research Centre (TRANSyT-UPM) Universidad Politécnica de Madrid, ETSI Caminos, Canales y Puertos, Prof. Aranguren s/n, 28040 Madrid (Spain); Centro de investigación del transporte, TRANSyT-UPM, ETSI Caminos, Canales y Puertos, Universidad Politécnica de Madrid, Prof. Aranguren s/n, 28040 Madrid (Spain); Department of Construction and Rural Roads, Forestry Engineering School, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); and others

2014-01-15

The assessment of different alternatives in road-corridor planning must be based on a number of well-defined territorial variables that serve as decision making criteria, and this requires a high-quality preliminary environmental assessment study. In Spain the formal specifications for the technical requirements stipulate the constraints that must be considered in the early stages of defining road corridors, but not how they should be analyzed and ranked. As part of the feasibility study of a new road definition, the most common methodology is to establish different levels of Territorial Carrying Capacity (TCC) in the study area in order to summarize the territorial variables on thematic maps and to ease the tracing process of road-corridor layout alternatives. This paper explores the variables used in 22 road-construction projects conducted by the Ministry of Public Works that were subject to the Spanish EIA regulation and published between 2006 and 2008. The aim was to evaluate the quality of the methods applied and the homogeneity and suitability of the variables used for defining the TCC. The variables were clustered into physical, environmental, land-use and cultural constraints for the purpose of comparing the TCC values assigned in the studies reviewed. We found the average quality of the studies to be generally acceptable in terms of the justification of the methodology, the weighting and classification of the variables, and the creation of a synthesis map. Nevertheless, the methods for assessing the TCC are not sufficiently standardized; there is a lack of uniformity in the cartographic information sources and methodologies for the TCC valuation. -- Highlights: • We explore 22 road-corridor planning studies subjected to the Spanish EIA regulation. • We analyze the variables selected for defining territorial carrying capacity. • The quality of the studies is acceptable (methodology, variable weighting, mapping). • There is heterogeneity in the

Integrated corridor management : phase I, concept development and foundational research. Task 3.4, identify integrated corridor management institutional strategies and administration

Science.gov (United States)

2006-04-12

Task 3 involves overall foundational research to further the understanding of various aspects of Integrated Corridor Management (ICM) and to identify integration issues needed to evaluate the feasibility of the ICM initiative. The focus of Task 3.4 a...

ON THE FORMATION OF «ECONOMIC CORRIDOR SILK ROAD»: STATUS, PROBLEMS AND PROSPECTS

Directory of Open Access Journals (Sweden)

Rashid K. Alimov

2013-01-01

Full Text Available The author analyzes the status and prospect of Tajik-Chinese relations in the context of the initiative of the President of the PRC on establishing of an economic corridor the Silk Road. A detailed characteristic of expected challenges and benefits for countries of Central Asia and China is given. Special attention is spent on the possibilities of developing of relations between Tajikistan and China, that have risen to the level of strategic partnership.

The change in spatial distribution of upper trapezius muscle activity is correlated to contraction duration.

Science.gov (United States)

Farina, Dario; Leclerc, Frédéric; Arendt-Nielsen, Lars; Buttelli, Olivier; Madeleine, Pascal

2008-02-01

The aim of the study was to confirm the hypothesis that the longer a contraction is sustained, the larger are the changes in the spatial distribution of muscle activity. For this purpose, surface electromyographic (EMG) signals were recorded with a 13 x 5 grid of electrodes from the upper trapezius muscle of 11 healthy male subjects during static contractions with shoulders 90 degrees abducted until endurance. The entropy (degree of uniformity) and center of gravity of the EMG root mean square map were computed to assess spatial inhomogeneity in muscle activation and changes over time in EMG amplitude spatial distribution. At the endurance time, entropy decreased (mean+/-SD, percent change 2.0+/-1.6%; Pgrid) root mean square was positively correlated with the shift in the center of gravity (R(2)=0.51, P<0.05). Moreover, the shift in the center of gravity was negatively correlated to both initial and final (at the endurance) entropy (R(2)=0.54 and R(2)=0.56, respectively; P<0.01 in both cases), indicating that subjects with less uniform root mean square maps had larger shift of the center of gravity over time. The spatial changes in root mean square EMG were likely due to spatially-dependent changes in motor unit activation during the sustained contraction. It was concluded that the changes in spatial muscle activity distribution play a role in the ability to maintain a static contraction.

Integrated corridor management (ICM) knowledge and technology transfer (KTT).

Science.gov (United States)

2014-01-01

The ICM approach involves aggressive, : proactive integration of infrastructure : along major corridors so that : transportation professionals can fully : leverage all existing modal choices : and assets. ICM helps transportation : leaders improve tr...

MOSAIC : Model of Sustainability and Integrated Corridors : [research summary].

Science.gov (United States)

2015-02-01

In order to improve transportation, environmental, and livability : conditions for Maryland residents and visitors, the Maryland : State Highway Administration (SHA) initiated planning efforts to : improve critical highway corridors and promote susta...

How bicycle level of traffic stress correlate with reported cyclist accidents injury severities: A geospatial and mixed logit analysis.

Science.gov (United States)

Chen, Chen; Anderson, Jason C; Wang, Haizhong; Wang, Yinhai; Vogt, Rachel; Hernandez, Salvador

2017-11-01

Transportation agencies need efficient methods to determine how to reduce bicycle accidents while promoting cycling activities and prioritizing safety improvement investments. Many studies have used standalone methods, such as level of traffic stress (LTS) and bicycle level of service (BLOS), to better understand bicycle mode share and network connectivity for a region. However, in most cases, other studies rely on crash severity models to explain what variables contribute to the severity of bicycle related crashes. This research uniquely correlates bicycle LTS with reported bicycle crash locations for four cities in New Hampshire through geospatial mapping. LTS measurements and crash locations are compared visually using a GIS framework. Next, a bicycle injury severity model, that incorporates LTS measurements, is created through a mixed logit modeling framework. Results of the visual analysis show some geospatial correlation between higher LTS roads and "Injury" type bicycle crashes. It was determined, statistically, that LTS has an effect on the severity level of bicycle crashes and high LTS can have varying effects on severity outcome. However, it is recommended that further analyses be conducted to better understand the statistical significance and effect of LTS on injury severity. As such, this research will validate the use of LTS as a proxy for safety risk regardless of the recorded bicycle crash history. This research will help identify the clustering patterns of bicycle crashes on high-risk corridors and, therefore, assist with bicycle route planning and policy making. This paper also suggests low-cost countermeasures or treatments that can be implemented to address high-risk areas. Specifically, with the goal of providing safer routes for cyclists, such countermeasures or treatments have the potential to substantially reduce the number of fatalities and severe injuries. Published by Elsevier Ltd.

Time-varying correlations in global real estate markets: A multivariate GARCH with spatial effects approach

Science.gov (United States)

Gu, Huaying; Liu, Zhixue; Weng, Yingliang

2017-04-01

The present study applies the multivariate generalized autoregressive conditional heteroscedasticity (MGARCH) with spatial effects approach for the analysis of the time-varying conditional correlations and contagion effects among global real estate markets. A distinguishing feature of the proposed model is that it can simultaneously capture the spatial interactions and the dynamic conditional correlations compared with the traditional MGARCH models. Results reveal that the estimated dynamic conditional correlations have exhibited significant increases during the global financial crisis from 2007 to 2009, thereby suggesting contagion effects among global real estate markets. The analysis further indicates that the returns of the regional real estate markets that are in close geographic and economic proximities exhibit strong co-movement. In addition, evidence of significantly positive leverage effects in global real estate markets is also determined. The findings have significant implications on global portfolio diversification opportunities and risk management practices.

Statewide GIS mapping of recurring congestion corridors : final report.

Science.gov (United States)

2009-07-01

Recurring congestion occurs when travel demand reaches or exceeds the available roadway : capacity. This project developed an interactive geographic information system (GIS) map of the : recurring congestion corridors (labeled herein as hotspots) in ...

Conservation Lands and Preserves, Private - Volusia County Conservation Corridor

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — The Volusia Conservation Corridor (VCC) is a mosaic of contiguous parcels of land, approximately 55,000 acres in size, which sits essentially in the middle of the...

Quantifying spatial scaling patterns and their local and regional correlates in headwater streams: implications for resilience

Directory of Open Access Journals (Sweden)

Emma Göthe

2014-09-01

Full Text Available The distribution of functional traits within and across spatiotemporal scales has been used to quantify and infer the relative resilience across ecosystems. We use explicit spatial modeling to evaluate within- and cross-scale redundancy in headwater streams, an ecosystem type with a hierarchical and dendritic network structure. We assessed the cross-scale distribution of functional feeding groups of benthic invertebrates in Swedish headwater streams during two seasons. We evaluated functional metrics, i.e., Shannon diversity, richness, and evenness, and the degree of redundancy within and across modeled spatial scales for individual feeding groups. We also estimated the correlates of environmental versus spatial factors of both functional composition and the taxonomic composition of functional groups for each spatial scale identified. Measures of functional diversity and within-scale redundancy of functions were similar during both seasons, but both within- and cross-scale redundancy were low. This apparent low redundancy was partly attributable to a few dominant taxa explaining the spatial models. However, rare taxa with stochastic spatial distributions might provide additional information and should therefore be considered explicitly for complementing future resilience assessments. Otherwise, resilience may be underestimated. Finally, both environmental and spatial factors correlated with the scale-specific functional and taxonomic composition. This finding suggests that resilience in stream networks emerges as a function of not only local conditions but also regional factors such as habitat connectivity and invertebrate dispersal.

Louisiana Speaks Transportation Option B Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_b_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

Louisiana Speaks Transportation Option C Transit Corridors, UTM Zone 15N NAD 83, Louisiana Recovery Authority (2007), [louisiana_speaks_transportation_option_c_transit_corridors

Data.gov (United States)

Louisiana Geographic Information Center — This GIS shapefile data illustrates the regional, subregional, and local transit corridors included in the Louisiana Speaks Regional Plan community growth option of...

The Effect of Velocity Correlation on the Spatial Evolution of Breakthrough Curves in Heterogeneous Media

Science.gov (United States)

Massoudieh, A.; Dentz, M.; Le Borgne, T.

2017-12-01

In heterogeneous media, the velocity distribution and the spatial correlation structure of velocity for solute particles determine the breakthrough curves and how they evolve as one moves away from the solute source. The ability to predict such evolution can help relating the spatio-statistical hydraulic properties of the media to the transport behavior and travel time distributions. While commonly used non-local transport models such as anomalous dispersion and classical continuous time random walk (CTRW) can reproduce breakthrough curve successfully by adjusting the model parameter values, they lack the ability to relate model parameters to the spatio-statistical properties of the media. This in turns limits the transferability of these models. In the research to be presented, we express concentration or flux of solutes as a distribution over their velocity. We then derive an integrodifferential equation that governs the evolution of the particle distribution over velocity at given times and locations for a particle ensemble, based on a presumed velocity correlation structure and an ergodic cross-sectional velocity distribution. This way, the spatial evolution of breakthrough curves away from the source is predicted based on cross-sectional velocity distribution and the connectivity, which is expressed by the velocity transition probability density. The transition probability is specified via a copula function that can help construct a joint distribution with a given correlation and given marginal velocities. Using this approach, we analyze the breakthrough curves depending on the velocity distribution and correlation properties. The model shows how the solute transport behavior evolves from ballistic transport at small spatial scales to Fickian dispersion at large length scales relative to the velocity correlation length.

Investigation of spatial correlation in MR images of human cerebral white matter using geostatistical methods

International Nuclear Information System (INIS)

Keil, Fabian

2014-01-01

Investigating the structure of human cerebral white matter is gaining interest in the neurological as well as in the neuroscientific community. It has been demonstrated in many studies that white matter is a very dynamic structure, rather than a static construct which does not change for a lifetime. That means, structural changes within white matter can be observed even on short timescales, e.g. in the course of normal ageing, neurodegenerative diseases or even during learning processes. To investigate these changes, one method of choice is the texture analysis of images obtained from white matter. In this regard, MRI plays a distinguished role as it provides a completely non-invasive way of acquiring in vivo images of human white matter. This thesis adapted a statistical texture analysis method, known as variography, to quantify the spatial correlation of human cerebral white matter based on MR images. This method, originally introduced in geoscience, relies on the idea of spatial correlation in geological phenomena: in naturally grown structures near things are correlated stronger to each other than distant things. This work reveals that the geological principle of spatial correlation can be applied to MR images of human cerebral white matter and proves that variography is an adequate method to quantify alterations therein. Since the process of MRI data acquisition is completely different to the measuring process used to quantify geological phenomena, the variographic analysis had to be adapted carefully to MR methods in order to provide a correctly working methodology. Therefore, theoretical considerations were evaluated with numerical samples in a first, and validated with real measurements in a second step. It was shown that MR variography facilitates to reduce the information stored in the texture of a white matter image to a few highly significant parameters, thereby quantifying heterogeneity and spatial correlation distance with an accuracy better than 5

Introduction: translocal development, development corridors and development chains.

NARCIS (Netherlands)

Zoomers, E.B.; Westen, A.C.M. van

2011-01-01

This paper offers an introduction to this Special Issue of International Development Planning Review. It uses the concepts of translocal development, development corridors and development chains to secure a better grasp of what development means in the context of globalisation and how ‘local

Sacroiliac secure corridor: analysis for safe insertion of iliosacral screws

Directory of Open Access Journals (Sweden)

Henrique Alves Cruz

2013-08-01

Full Text Available OBJECTIVE: Posterior pelvic lesions, especially of the sacral-iliac joint, have high mortality and morbidity risks. Definitive fixation is necessary for the joint stabilization, and one option is the sacral percutaneous pinning with screws. Proximity to important structures to this region brings risks to the fixation procedure; therefore, it is important to know the tridimensional anatomy of the pelvis posterior region. Deviations of the surgeon's hand of four degrees may target the screws to those structures; dimorphisms of the upper sacrum and a poor lesion reduction may redound in a screw malpositioning. This study is aimed to evaluate the dimensions of a safe surgical corridor for safe sacroiliac screw insertion and relations with age and sex of the patients. METHOD: One hundred randomly selected pelvis CTs of patients with no pelvic diseases, seen at a tertiary care teaching Hospital. Measurements were made by computer and the safest area for screw insertion was calculated by two methods. The results were expressed in mm (not in degrees, in order to be a further surgical reference. RESULTS: There was a significant size difference in the analyzed sacral vertebra, differing on a wider size in men than in women. There was no significant statistical difference between vertebral size and age. By both methods, a safe area for screw insertion could be defined. CONCLUSION: Age does not influence the width of the surgical corridor. The surgeon has a safe corridor considered narrower when inserting screws in a female pelvis than when in a male one. However, as the smallest vertebra found (feminine was considered for statics, it was concluded that this corridor is 20 mm wide in any direction, taking as a reference the centrum of the vertebra.

Regional Disparities in Education Attainment Level in the European Union: A Spatial Approach

Directory of Open Access Journals (Sweden)

Chocholatá Michaela

2017-10-01

Full Text Available This article deals with the analysis of education attainment level across the 252 NUTS 2 regions of the European Union (EU with consideration of the spatial aspect. Since the individual EU regions cannot be seen as isolated, the main aim of this article is to assess the impact of location on the education attainment level (percentage of population aged 25–64 with at least upper secondary education during the period 2007–2015, as well as to investigate the impact of regional growth 2014/2007 on the education attainment level in 2015. The spatial analysis proved the existence of positive spatial autocorrelation and persistence of disparities in education attainment level across EU regions during the analysed period. The results of econometric analysis confirmed the expected positive impact of economic growth on education attainment level as well as the necessity to incorporate the spatial dimension into the model.

Frequency and spatial correlation functions in a fading communication channel through the ionosphere

International Nuclear Information System (INIS)

Liu, C.H.; Yeh, K.C.

1975-01-01

Equations for the two-frequency two-position mutual coherence functions are derived under the usual parabolic and Markov approximations. These equations are then solved numerically. It is shown that the mutual coherence functions occur naturally in the study of pulse distortion through a random communication channel and in the investigation of signal correlations. Contour plots of correlation functions show the possibility of having equal values at two frequency separations for a given spatial separation. This behavior is explainable in terms of overlapping Fresnel zones

California air transportation study: A transportation system for the California Corridor of the year 2010

Science.gov (United States)

1989-01-01

To define and solve the problems of transportation in the California Corrider in the year 2010, the 1989 California Polytechnic State University Aeronautical Engineering Senior Design class determined future corridor transportation needs and developed a system to meet the requirements. A market study, which included interpreting travel demand and gauging the future of regional and national air travel in and out of the corridor, allowed the goals of the project to be accurately refined. Comprehensive trade-off studies of several proposed transporation systems were conducted to determine which components would form the final proposed system. Preliminary design and further analysis were performed for each resulting component. The proposed system consists of three vehicles and a special hub or mode mixer, the Corridor Access Port (CAP). The vehicles are: (1) an electric powered aircraft to serve secondary airports and the CAP; (2) a high speed magnetic levitation train running through the CAP and the high population density areas of the corridor; and (3) a vertical takeoff and landing tilt rotor aircraft to serve both intercity and intrametropolitan travelers from the CAP and city vertiports. The CAP is a combination and an extension of the hub, mode mixer, and Wayport concepts. The CAP is an integrated part of the system which meets the travel demands in the corridor, and interfaces with interstate and international travel.

Spatial transcriptomics: paving the way for tissue-level systems biology.

Science.gov (United States)

Moor, Andreas E; Itzkovitz, Shalev

2017-08-01

The tissues in our bodies are complex systems composed of diverse cell types that often interact in highly structured repeating anatomical units. External gradients of morphogens, directional blood flow, as well as the secretion and absorption of materials by cells generate distinct microenvironments at different tissue coordinates. Such spatial heterogeneity enables optimized function through division of labor among cells. Unraveling the design principles that govern this spatial division of labor requires techniques to quantify the entire transcriptomes of cells while accounting for their spatial coordinates. In this review we describe how recent advances in spatial transcriptomics open the way for tissue-level systems biology. Copyright © 2017 Elsevier Ltd. All rights reserved.

33 CFR 334.770 - Gulf of Mexico and St. Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor...

Science.gov (United States)

2010-07-01

... Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor, Tyndall Air Force Base, Fla.; restricted.... Andrew Sound, south of East Bay, Fla., Tyndall Drone Launch Corridor, Tyndall Air Force Base, Fla... referred to as the “Tyndall Drone Launch Corridor.” (b) The regulations. (1) Military usage of areas is...

Langevin Dynamics with Spatial Correlations as a Model for Electron-Phonon Coupling

Science.gov (United States)

Tamm, A.; Caro, M.; Caro, A.; Samolyuk, G.; Klintenberg, M.; Correa, A. A.

2018-05-01

Stochastic Langevin dynamics has been traditionally used as a tool to describe nonequilibrium processes. When utilized in systems with collective modes, traditional Langevin dynamics relaxes all modes indiscriminately, regardless of their wavelength. We propose a generalization of Langevin dynamics that can capture a differential coupling between collective modes and the bath, by introducing spatial correlations in the random forces. This allows modeling the electronic subsystem in a metal as a generalized Langevin bath endowed with a concept of locality, greatly improving the capabilities of the two-temperature model. The specific form proposed here for the spatial correlations produces a physical wave-vector and polarization dependency of the relaxation produced by the electron-phonon coupling in a solid. We show that the resulting model can be used for describing the path to equilibration of ions and electrons and also as a thermostat to sample the equilibrium canonical ensemble. By extension, the family of models presented here can be applied in general to any dense system, solids, alloys, and dense plasmas. As an example, we apply the model to study the nonequilibrium dynamics of an electron-ion two-temperature Ni crystal.

76 FR 56471 - Meeting of the John H. Chafee Blackstone River Valley National Heritage Corridor Commission

Science.gov (United States)

2011-09-13

...] Meeting of the John H. Chafee Blackstone River Valley National Heritage Corridor Commission AGENCY: National Heritage Corridor Commission, John H. Chafee Blackstone River Valley, National Park Service... Advisory Committee Act, 5 U.S.C. Appendix, that the John H. Chafee Blackstone River Valley National...

A GIS-based spatial correlation analysis for ambient air pollution and AECOPD hospitalizations in Jinan, China.

Science.gov (United States)

Wang, Wenqiao; Ying, Yangyang; Wu, Quanyuan; Zhang, Haiping; Ma, Dedong; Xiao, Wei

2015-03-01

Acute exacerbations of COPD (AECOPD) are important events during disease procedure. AECOPD have negative effect on patients' quality of life, symptoms and lung function, and result in high socioeconomic costs. Though previous studies have demonstrated the significant association between outdoor air pollution and AECOPD hospitalizations, little is known about the spatial relationship utilized a spatial analyzing technique- Geographical Information System (GIS). Using GIS to investigate the spatial association between ambient air pollution and AECOPD hospitalizations in Jinan City, 2009. 414 AECOPD hospitalization cases in Jinan, 2009 were enrolled in our analysis. Monthly concentrations of five monitored air pollutants (NO2, SO2, PM10, O3, CO) during January 2009-December 2009 were provided by Environmental Protection Agency of Shandong Province. Each individual was geocoded in ArcGIS10.0 software. The spatial distribution of five pollutants and the temporal-spatial specific air pollutants exposure level for each individual was estimated by ordinary Kriging model. Spatial autocorrelation (Global Moran's I) was employed to explore the spatial association between ambient air pollutants and AECOPD hospitalizations. A generalized linear model (GLM) using a Poisson distribution with log-link function was used to construct a core model. At residence, concentrations of SO2, PM10, NO2, CO, O3 and AECOPD hospitalization cases showed statistical significant spatially clustered. The Z-score of SO2, PM10, CO, O3, NO2 at residence is 15.88, 13.93, 12.60, 4.02, 2.44 respectively, while at workplace, concentrations of PM10, SO2, O3, CO and AECOPD hospitalization cases showed statistical significant spatially clustered. The Z-score of PM10, SO2, O3, CO at workplace is 11.39, 8.07, 6.10, and 5.08 respectively. After adjusting for potential confounders in the model, only the PM10 concentrations at workplace showed statistical significance, with a 10 μg/m(3) increase of PM10 at

Safe corridors for K-wiring in phalangeal fractures

Directory of Open Access Journals (Sweden)

C Rex

2015-01-01

Conclusion: K-wiring through the safe corridor has proved to yield the best clinical results because of least tethering of soft tissues as evidenced by performing "on-table active finger movement test" at the time of surgery. We strongly recommend K-wiring through safe portals in all phalangeal fractures.

I-15 integrated corridor management system : project management plan.

Science.gov (United States)

2011-06-01

The Project Management Plan (PMP) assists the San Diego ICM Team by defining a procedural framework for : management and control of the I-15 Integrated Corridor Management Demonstration Project, and development and : deployment of the ICM System. The...

A Study of the Groundwater Level Spatial Variability in the Messara Valley of Crete

Science.gov (United States)

Varouchakis, E. A.; Hristopulos, D. T.; Karatzas, G. P.

2009-04-01

The island of Crete (Greece) has a dry sub-humid climate and marginal groundwater resources, which are extensively used for agricultural activities and human consumption. The Messara valley is located in the south of the Heraklion prefecture, it covers an area of 398 km2, and it is the largest and most productive valley of the island. Over-exploitation during the past thirty (30) years has led to a dramatic decrease of thirty five (35) meters in the groundwater level. Possible future climatic changes in the Mediterranean region, potential desertification, population increase, and extensive agricultural activity generate concern over the sustainability of the water resources of the area. The accurate estimation of the water table depth is important for an integrated groundwater resource management plan. This study focuses on the Mires basin of the Messara valley for reasons of hydro-geological data availability and geological homogeneity. The research goal is to model and map the spatial variability of the basin's groundwater level accurately. The data used in this study consist of seventy (70) piezometric head measurements for the hydrological year 2001-2002. These are unevenly distributed and mostly concentrated along a temporary river that crosses the basin. The range of piezometric heads varies from an extreme low value of 9.4 meters above sea level (masl) to 62 masl, for the wet period of the year (October to April). An initial goal of the study is to develop spatial models for the accurate generation of static maps of groundwater level. At a second stage, these maps should extend the models to dynamic (space-time) situations for the prediction of future water levels. Preliminary data analysis shows that the piezometric head variations are not normally distributed. Several methods including Box-Cox transformation and a modified version of it, transgaussian Kriging, and Gaussian anamorphosis have been used to obtain a spatial model for the piezometric head. A

Spatial Skill Profile of Mathematics Pre-Service Teachers

Science.gov (United States)

Putri, R. O. E.

2018-01-01

This study is aimed to investigate the spatial intelligence of mathematics pre-service teachers and find the best instructional strategy that facilitates this aspect. Data were collected from 35 mathematics pre-service teachers. The Purdue Spatial Visualization Test (PSVT) was used to identify the spatial skill of mathematics pre-service teachers. Statistical analysis indicate that more than 50% of the participants possessed spatial skill in intermediate level, whereas the other were in high and low level of spatial skill. The result also shows that there is a positive correlation between spatial skill and mathematics ability, especially in geometrical problem solving. High spatial skill students tend to have better mathematical performance compare to those in two other levels. Furthermore, qualitative analysis reveals that most students have difficulty in manipulating geometrical objects mentally. This problem mostly appears in intermediate and low-level spatial skill students. The observation revealed that 3-D geometrical figures is the best method that can overcome the mentally manipulation problem and develop the spatial visualization. Computer application can also be used to improve students’ spatial skill.

Spatially Correlated, Single Nanomaterial-Level Structural and Optical Profiling of Cu-Doped ZnO Nanorods Synthesized via Multifunctional Silicides

Directory of Open Access Journals (Sweden)

Johnson Truong

2018-04-01

Full Text Available We demonstrate a straightforward and effective method to synthesize vertically oriented, Cu-doped ZnO nanorods (NRs using a novel multipurpose platform of copper silicide nanoblocks (Cu3Si NBs preformed laterally in well-defined directions on Si. The use of the surface-organized Cu3Si NBs for ZnO NR growth successfully results in densely assembled Cu-doped ZnO NRs on each NB platform, whose overall structures resemble thick bristles on a brush head. We show that Cu3Si NBs can uniquely serve as a catalyst for ZnO NRs, a local dopant source of Cu, and a prepatterned guide to aid the local assembly of the NRs on the growth substrate. We also ascertain the crystalline structures, optical properties, and spectroscopic signatures of the Cu-doped ZnO NRs produced on the NBs, both at each module of NRs/NB and at their ensemble level. Subsequently, we determine their augmented properties relative to the pristine form of undoped ZnO NRs and the source material of Cu3Si NBs. We provide spatially correlated structural and optical data for individual modules of Cu-doped ZnO NRs assembled on a Cu3Si NB by resolving them along the different positions on the NB. Ensemble-averaged versus individual behaviors of Cu-doped ZnO NRs on Cu3Si NBs are then compared. We further discuss the potential impact of such ZnO-derived NRs on their relatively unexplored biological and biomedical applications. Our efforts will be particularly useful when exploiting each integrated module of self-aligned, Cu-doped ZnO NRs on a NB as a discretely addressable, active element in solid-state sensors and miniaturized luminescent bioprobes.

Delineating and identifying long-term changes in the whooping crane (Grus americana) migration corridor

Science.gov (United States)

Pearse, Aaron T.; Rabbe, Matt; Juliusson, Lara M.; Bidwell, Mark T.; Craig-Moore, Lea; Brandt, David; Harrell, Wade C.

2018-01-01

Defining and identifying changes to seasonal ranges of migratory species is required for effective conservation. Historic sightings of migrating whooping cranes (Grus americana) have served as sole source of information to define a migration corridor in the Great Plains of North America (i.e., Canadian Prairies and United States Great Plains) for this endangered species. We updated this effort using past opportunistic sightings from 1942–2016 (n = 5,055) and more recent (2010–2016) location data from 58 telemetered birds (n = 4,423) to delineate migration corridors that included 50%, 75%, and 95% core areas. All migration corridors were well defined and relatively compact, with the 95% core corridor averaging 294 km wide, although it varied approximately ±40% in width from 170 km in central Texas to 407 km at the international border of the United States and Canada. Based on historic sightings and telemetry locations, we detected easterly movements in locations over time, primarily due to locations west of the median shifting east. This shift occurred from northern Oklahoma to central Saskatchewan at an average rate of 1.2 km/year (0.3–2.8 km/year). Associated with this directional shift was a decrease in distance of locations from the median in the same region averaging -0.7 km/year (-0.3–-1.3 km/year), suggesting a modest narrowing of the migration corridor. Changes in the corridor over the past 8 decades suggest that agencies and organizations interested in recovery of this species may need to modify where conservation and recovery actions occur. Whooping cranes showed apparent plasticity in their migratory behavior, which likely has been necessary for persistence of a wetland-dependent species migrating through the drought-prone Great Plains. Behavioral flexibility will be useful for whooping cranes to continue recovery in a future of uncertain climate and land use changes throughout their annual range.

Spatial and statistical methods for correlating the interaction between groundwater contamination and tap water exposure in karst regions

Science.gov (United States)

Padilla, I. Y.; Rivera, V. L.; Macchiavelli, R. E.; Torres Torres, N. I.

2016-12-01

Groundwater systems in karst regions are highly vulnerable to contamination and have an enormous capacity to store and rapidly convey pollutants to potential exposure zones over long periods of time. Contaminants in karst aquifers used for drinking water purposes can, therefore, enter distributions lines and the tap water point of use. This study applies spatial and statistical analytical methods to assess potential correlations between contaminants in a karst groundwater system in northern Puerto Rico and exposure in the tap water. It focuses on chlorinated volatile organic compounds (CVOC) and phthalates because of their ubiquitous presence in the environment and the potential public health impacts. The work integrates historical data collected from regulatory agencies and current field measurements involving groundwater and tap water sampling and analysis. Contaminant distributions and cluster analysis is performed with Geographic Information System technology. Correlations between detection frequencies and contaminants concentration in source groundwater and tap water point of use are assessed using Pearson's Chi Square and T-Test analysis. Although results indicate that correlations are contaminant-specific, detection frequencies are generally higher for total CVOC in groundwater than tap water samples, but greater for phthalates in tap water than groundwater samples. Spatial analysis shows widespread distribution of CVOC and phthalates in both groundwater and tap water, suggesting that contamination comes from multiple sources. Spatial correlation analysis indicates that association between tap water and groundwater contamination depends on the source and type of contaminants, spatial location, and time. Full description of the correlations may, however, need to take into consideration variable anthropogenic interventions.

Flow distributions and spatial correlations in human brain capillary networks

Science.gov (United States)

Lorthois, Sylvie; Peyrounette, Myriam; Larue, Anne; Le Borgne, Tanguy

2015-11-01

The vascular system of the human brain cortex is composed of a space filling mesh-like capillary network connected upstream and downstream to branched quasi-fractal arterioles and venules. The distribution of blood flow rates in these networks may affect the efficiency of oxygen transfer processes. Here, we investigate the distribution and correlation properties of blood flow velocities from numerical simulations in large 3D human intra-cortical vascular network (10000 segments) obtained from an anatomical database. In each segment, flow is solved from a 1D non-linear model taking account of the complex rheological properties of blood flow in microcirculation to deduce blood pressure, blood flow and red blood cell volume fraction distributions throughout the network. The network structural complexity is found to impart broad and spatially correlated Lagrangian velocity distributions, leading to power law transit time distributions. The origins of this behavior (existence of velocity correlations in capillary networks, influence of the coupling with the feeding arterioles and draining veins, topological disorder, complex blood rheology) are studied by comparison with results obtained in various model capillary networks of controlled disorder. ERC BrainMicroFlow GA615102, ERC ReactiveFronts GA648377.

Movements and corridors of African elephants in relation to protected areas

Science.gov (United States)

Douglas-Hamilton, I.; Krink, T.; Vollrath, F.

2005-04-01

Understanding how mammals satisfy their need for space in fragmenting ecosystems is crucial for ecosystem conservation. Using state-of-the-art global positioning system (GPS) technology we tracked 11 focal African elephants (Loxodonta africana) in Kenya at 3-hourly fix intervals and collected between 34 and 406 days per individual. Our recordings gave a high spatio-temporal resolution compared to previous studies and allowed novel insights into range use. The actual ranges of the tracked elephants are smaller than usually represented. Moreover, the ranges in our sample were complex and not confined to officially designated protected areas, except where fenced. All the unfenced elephants in our sample had distinct `home sectors' linked by `travel' corridors. Within each home sector the elephants concentrated in favourite `core zones'. Such core zones tended to lie in protected areas whereas corridors typically crossed unprotected range. Elephants moved significantly faster along corridors than elsewhere in their range, which suggests awareness of danger outside the protected area. We conclude that understanding the complex use of an animal's range is crucial for conservation planning aiming to balance animal interests with those of human beings that co-habit in their range.

Using niche-modelling and species-specific cost analyses to determine a multispecies corridor in a fragmented landscape

Science.gov (United States)

Zurano, Juan Pablo; Selleski, Nicole; Schneider, Rosio G.

2017-01-01

Misiones, Argentina, contains the largest remaining tract of Upper Paraná Atlantic Forest ecoregion; however, ~50% of native forest is unprotected and located in a mosaic of plantations, agriculture, and pastures. Existing protected areas are becoming increasingly isolated due to ongoing habitat modification. These factors, combined with lower than expected regional carnivore densities, emphasize the need to understand the effect of fragmentation on animal movement and connectivity between protected areas. Using detection dogs and genetic analyses of scat, we collected data on jaguars (Panthera onca), pumas (Puma concolor), ocelots (Leopardus pardalis), oncillas (Leopardus tigrinus), and bush dogs (Speothos venaticus) across habitats that varied in vegetation, disturbance, human proximity, and protective status. With MaxEnt we evaluated habitat use, habitat suitability, and potential species richness for the five carnivores across northern-central Misiones, Argentina. Through a multifaceted cost analysis that included unique requirements of each carnivore and varying degrees of overlap among them, we determined the optimal location for primary/secondary corridors that would link the northern-central zones of the Green Corridor in Misiones and identified areas within these corridors needing priority management. A secondary analysis, comparing these multispecies corridors with the jaguar’s unique requirements, demonstrated that this multispecies approach balanced the preferences of all five species and effectively captured areas required by this highly restricted and endangered carnivore. We emphasize the potential importance of expanding beyond a single umbrella or focal species when developing biological corridors that aim to capture the varied ecological requirements of coexisting species and ecological processes across the landscape. Detection dogs and genetic analyses of scat allow data on multiple species to be collected efficiently across multiple habitat

Empowerment Zones and Enterprise Districts - MDC_TargetUrbanAreaCorridor

Data.gov (United States)

NSGIC Local Govt | GIS Inventory — A polygon feature class of Miami-Dade County, Targeted Urban Area Corridors. This coverage was created for the Office of Community & Economic Development (OCED)...

Investigation of spatial correlation in MR images of human cerebral white matter using geostatistical methods

Energy Technology Data Exchange (ETDEWEB)

Keil, Fabian

2014-03-20

Investigating the structure of human cerebral white matter is gaining interest in the neurological as well as in the neuroscientific community. It has been demonstrated in many studies that white matter is a very dynamic structure, rather than a static construct which does not change for a lifetime. That means, structural changes within white matter can be observed even on short timescales, e.g. in the course of normal ageing, neurodegenerative diseases or even during learning processes. To investigate these changes, one method of choice is the texture analysis of images obtained from white matter. In this regard, MRI plays a distinguished role as it provides a completely non-invasive way of acquiring in vivo images of human white matter. This thesis adapted a statistical texture analysis method, known as variography, to quantify the spatial correlation of human cerebral white matter based on MR images. This method, originally introduced in geoscience, relies on the idea of spatial correlation in geological phenomena: in naturally grown structures near things are correlated stronger to each other than distant things. This work reveals that the geological principle of spatial correlation can be applied to MR images of human cerebral white matter and proves that variography is an adequate method to quantify alterations therein. Since the process of MRI data acquisition is completely different to the measuring process used to quantify geological phenomena, the variographic analysis had to be adapted carefully to MR methods in order to provide a correctly working methodology. Therefore, theoretical considerations were evaluated with numerical samples in a first, and validated with real measurements in a second step. It was shown that MR variography facilitates to reduce the information stored in the texture of a white matter image to a few highly significant parameters, thereby quantifying heterogeneity and spatial correlation distance with an accuracy better than 5

vegetation biomass prediction in the cattle corridor of uganda

African Journals Online (AJOL)

Prof. Adipala Ekwamu

3Ministry of Water and Environment, Climate Change Unit, P. O. Box 2811, Kampala, Uganda ... (r=0.99). Precipitation has influenced vegetative biomass in the cattle corridor as there is a positive .... since they are cloud free (Campbell, 2006).

A new maximum likelihood blood velocity estimator incorporating spatial and temporal correlation

DEFF Research Database (Denmark)

Schlaikjer, Malene; Jensen, Jørgen Arendt

2001-01-01

and space. This paper presents a new estimator (STC-MLE), which incorporates the correlation property. It is an expansion of the maximum likelihood estimator (MLE) developed by Ferrara et al. With the MLE a cross-correlation analysis between consecutive RF-lines on complex form is carried out for a range...... of possible velocities. In the new estimator an additional similarity investigation for each evaluated velocity and the available velocity estimates in a temporal (between frames) and spatial (within frames) neighborhood is performed. An a priori probability density term in the distribution...... of the observations gives a probability measure of the correlation between the velocities. Both the MLE and the STC-MLE have been evaluated on simulated and in-vivo RF-data obtained from the carotid artery. Using the MLE 4.1% of the estimates deviate significantly from the true velocities, when the performance...

Impact of Non-Idealities System on Spatial Correlation in a Multi-Probe Based MIMO OTA Setup

DEFF Research Database (Denmark)

Fan, Wei; Nielsen, Jesper Ødum; Carreño, Xavier

2013-01-01

MIMO OTA testing methodologies are being intensively investigated by CTIA and 3GPP, where a multi-probe anechoic chamber based solution is an important candidate for future standardized testing. In this paper, the probes located on an OTA ring are used to reproduce the channel spatial information....... This paper investigates the extent to which we can emulate the channel spatial characteristics inside the test zone where the device under test is located. The focus is on performance deterioration introduced by system non-idealities on spatial correlation emulation in practical MIMO OTA test systems....

Atmospheric ventilation corridors and coefficients for pollution plume ...

African Journals Online (AJOL)

This study presents a comparative investigation of atmospheric ventilation corridors and coefficients for gaseous pollution plume released from an isolated industrial facility into the ambient air of the host community in Ile-Ife suburb, southwest Nigeria. For the months of September to December in the year 2012 and 2013, ...

Spatial modeling of households' knowledge about arsenic pollution in Bangladesh.

Science.gov (United States)

Sarker, M Mizanur Rahman

2012-04-01

Arsenic in drinking water is an important public health issue in Bangladesh, which is affected by households' knowledge about arsenic threats from their drinking water. In this study, spatial statistical models were used to investigate the determinants and spatial dependence of households' knowledge about arsenic risk. The binary join matrix/binary contiguity matrix and inverse distance spatial weight matrix techniques are used to capture spatial dependence in the data. This analysis extends the spatial model by allowing spatial dependence to vary across divisions and regions. A positive spatial correlation was found in households' knowledge across neighboring districts at district, divisional and regional levels, but the strength of this spatial correlation varies considerably by spatial weight. Literacy rate, daily wage rate of agricultural labor, arsenic status, and percentage of red mark tube well usage in districts were found to contribute positively and significantly to households' knowledge. These findings have policy implications both at regional and national levels in mitigating the present arsenic crisis and to ensure arsenic-free water in Bangladesh. Copyright © 2012 Elsevier Ltd. All rights reserved.

MOSAIC : Model Of Sustainability And Integrated Corridors, phase 3 : comprehensive model calibration and validation and additional model enhancement.

Science.gov (United States)

2015-02-01

The Maryland State Highway Administration (SHA) has initiated major planning efforts to improve transportation : efficiency, safety, and sustainability on critical highway corridors through its Comprehensive Highway Corridor : (CHC) program. This pro...

Impact of spatially correlated pore-scale heterogeneity on drying porous media

Science.gov (United States)

Borgman, Oshri; Fantinel, Paolo; Lühder, Wieland; Goehring, Lucas; Holtzman, Ran

2017-07-01

We study the effect of spatially-correlated heterogeneity on isothermal drying of porous media. We combine a minimal pore-scale model with microfluidic experiments with the same pore geometry. Our simulated drying behavior compares favorably with experiments, considering the large sensitivity of the emergent behavior to the uncertainty associated with even small manufacturing errors. We show that increasing the correlation length in particle sizes promotes preferential drying of clusters of large pores, prolonging liquid connectivity and surface wetness and thus higher drying rates for longer periods. Our findings improve our quantitative understanding of how pore-scale heterogeneity impacts drying, which plays a role in a wide range of processes ranging from fuel cells to curing of paints and cements to global budgets of energy, water and solutes in soils.

Spatial correlation characterization of a uniform circular array in 3D MIMO systems

KAUST Repository

Nadeem, Qurrat-Ul-Ain; Kammoun, Abla; Debbah, Merouane; Alouini, Mohamed-Slim

2016-01-01

In this paper, we consider a uniform circular array (UCA) of directional antennas at the base station (BS) and the mobile station (MS) and derive an exact closed-form expression for the spatial correlation present in the 3D multiple-input multiple-output (MIMO) channel constituted by these arrays. The underlying method leverages the mathematical convenience of the spherical harmonic expansion (SHE) of plane waves and the trigonometric expansion of Legendre and associated Legendre polynomials. In contrast to the existing results, this generalized closed-form expression is independent of the form of the underlying angular distributions and antenna patterns. Moreover, the incorporation of the elevation dimension into the antenna pattern and channel model renders the proposed expression extremely useful for the performance evaluation of 3D MIMO systems in the future. Verification is achieved with the help of simulation results, which highlight the dependence of the spatial correlation on channel and array parameters. An interesting interplay between the mean angle of departure (AoD), angular spread and the positioning of antennas in the array is demonstrated. © 2016 IEEE.

Spatial correlation characterization of a uniform circular array in 3D MIMO systems

KAUST Repository

Nadeem, Qurrat-Ul-Ain

2016-08-11

In this paper, we consider a uniform circular array (UCA) of directional antennas at the base station (BS) and the mobile station (MS) and derive an exact closed-form expression for the spatial correlation present in the 3D multiple-input multiple-output (MIMO) channel constituted by these arrays. The underlying method leverages the mathematical convenience of the spherical harmonic expansion (SHE) of plane waves and the trigonometric expansion of Legendre and associated Legendre polynomials. In contrast to the existing results, this generalized closed-form expression is independent of the form of the underlying angular distributions and antenna patterns. Moreover, the incorporation of the elevation dimension into the antenna pattern and channel model renders the proposed expression extremely useful for the performance evaluation of 3D MIMO systems in the future. Verification is achieved with the help of simulation results, which highlight the dependence of the spatial correlation on channel and array parameters. An interesting interplay between the mean angle of departure (AoD), angular spread and the positioning of antennas in the array is demonstrated. © 2016 IEEE.

Spatial Vertical Directionality and Correlation of Low-Frequency Ambient Noise in Deep Ocean Direct-Arrival Zones

Directory of Open Access Journals (Sweden)

Qiulong Yang

2018-01-01

Full Text Available Wind-driven and distant shipping noise sources contribute to the total noise field in the deep ocean direct-arrival zones. Wind-driven and distant shipping noise sources may significantly and simultaneously affect the spatial characteristics of the total noise field to some extent. In this work, a ray approach and parabolic equation solution method were jointly utilized to model the low-frequency ambient noise field in a range-dependent deep ocean environment by considering their calculation accuracy and efficiency in near-field wind-driven and far-field distant shipping noise fields. The reanalysis databases of National Center of Environment Prediction (NCEP and Volunteer Observation System (VOS were used to model the ambient noise source intensity and distribution. Spatial vertical directionality and correlation were analyzed in three scenarios that correspond to three wind speed conditions. The noise field was dominated by distant shipping noise sources when the wind speed was less than 3 m/s, and then the spatial vertical directionality and vertical correlation of the total noise field were nearly consistent with those of distant shipping noise field. The total noise field was completely dominated by near field wind generated noise sources when the wind speed was greater than 12 m/s at 150 Hz, and then the spatial vertical correlation coefficient and directionality pattern of the total noise field was approximately consistent with that of the wind-driven noise field. The spatial characteristics of the total noise field for wind speeds between 3 m/s and 12 m/s were the weighted results of wind-driven and distant shipping noise fields. Furthermore, the spatial characteristics of low-frequency ambient noise field were compared with the classical Cron/Sherman deep water noise field coherence function. Simulation results with the described modeling method showed good agreement with the experimental measurement results based on the vertical line

Spatial Vertical Directionality and Correlation of Low-Frequency Ambient Noise in Deep Ocean Direct-Arrival Zones

Science.gov (United States)

Yang, Qiulong; Yang, Kunde; Cao, Ran; Duan, Shunli

2018-01-01

Wind-driven and distant shipping noise sources contribute to the total noise field in the deep ocean direct-arrival zones. Wind-driven and distant shipping noise sources may significantly and simultaneously affect the spatial characteristics of the total noise field to some extent. In this work, a ray approach and parabolic equation solution method were jointly utilized to model the low-frequency ambient noise field in a range-dependent deep ocean environment by considering their calculation accuracy and efficiency in near-field wind-driven and far-field distant shipping noise fields. The reanalysis databases of National Center of Environment Prediction (NCEP) and Volunteer Observation System (VOS) were used to model the ambient noise source intensity and distribution. Spatial vertical directionality and correlation were analyzed in three scenarios that correspond to three wind speed conditions. The noise field was dominated by distant shipping noise sources when the wind speed was less than 3 m/s, and then the spatial vertical directionality and vertical correlation of the total noise field were nearly consistent with those of distant shipping noise field. The total noise field was completely dominated by near field wind generated noise sources when the wind speed was greater than 12 m/s at 150 Hz, and then the spatial vertical correlation coefficient and directionality pattern of the total noise field was approximately consistent with that of the wind-driven noise field. The spatial characteristics of the total noise field for wind speeds between 3 m/s and 12 m/s were the weighted results of wind-driven and distant shipping noise fields. Furthermore, the spatial characteristics of low-frequency ambient noise field were compared with the classical Cron/Sherman deep water noise field coherence function. Simulation results with the described modeling method showed good agreement with the experimental measurement results based on the vertical line array deployed near

Spatial variation of mercury levels in nesting Bonelli's eagles from Southwest Portugal: effects of diet composition and prey contamination

International Nuclear Information System (INIS)

Palma, Luis; Beja, Pedro; Tavares, Paula C.; Monteiro, Luis R.

2005-01-01

Mercury (Hg) was determined in adult Bonelli's eagles (Hieraaetus fasciatus) and their avian prey, from samples of feathers collected between 1992 and 2001 at the nesting sites of 21 pairs in Southwest Portugal. Eagle Hg levels showed great variation, reflecting primarily differences in diet composition and food chain biomagnification. Concentrations were positively correlated with the dietary proportion of insectivorous and omnivorous birds (e.g. egrets, corvids and thrushes), with very low levels for pairs feeding mainly on herbivores (e.g. rabbits, pigeons and partridges). Differences in prey contamination among breeding territories added to dietary effects in determining variation of Hg levels in eagles, shaping a spatial pattern that was largely consistent with a source of contamination in a coal-burning power-plant lying upwind of the study area. Despite this presumed contamination, Hg levels seemed to be of little concern to this eagle population, though there might be subtle deleterious effects on the reproductive output of a few pairs. This study emphasizes the need to account for dietary effects when biomonitoring Hg contamination using birds of prey. - The effects of diet composition and prey contamination added up to determine the spatial variation of Hg levels in breeding Bonelli's eagles

Temporal scaling and spatial statistical analyses of groundwater level fluctuations

Science.gov (United States)

Sun, H.; Yuan, L., Sr.; Zhang, Y.

2017-12-01

Natural dynamics such as groundwater level fluctuations can exhibit multifractionality and/or multifractality due likely to multi-scale aquifer heterogeneity and controlling factors, whose statistics requires efficient quantification methods. This study explores multifractionality and non-Gaussian properties in groundwater dynamics expressed by time series of daily level fluctuation at three wells located in the lower Mississippi valley, after removing the seasonal cycle in the temporal scaling and spatial statistical analysis. First, using the time-scale multifractional analysis, a systematic statistical method is developed to analyze groundwater level fluctuations quantified by the time-scale local Hurst exponent (TS-LHE). Results show that the TS-LHE does not remain constant, implying the fractal-scaling behavior changing with time and location. Hence, we can distinguish the potentially location-dependent scaling feature, which may characterize the hydrology dynamic system. Second, spatial statistical analysis shows that the increment of groundwater level fluctuations exhibits a heavy tailed, non-Gaussian distribution, which can be better quantified by a Lévy stable distribution. Monte Carlo simulations of the fluctuation process also show that the linear fractional stable motion model can well depict the transient dynamics (i.e., fractal non-Gaussian property) of groundwater level, while fractional Brownian motion is inadequate to describe natural processes with anomalous dynamics. Analysis of temporal scaling and spatial statistics therefore may provide useful information and quantification to understand further the nature of complex dynamics in hydrology.

Correlations of hair level with salivary level in cortisol and cortisone.

Science.gov (United States)

Zhang, Quan; Chen, Zheng; Chen, Shenghuo; Yu, Tian; Wang, Juxia; Wang, Weiwen; Deng, Huihua

2018-01-15

Contrary findings exist on the consistency between hair cortisol and salivary cortisol in assessing the basal activity of the hypothalamic-pituitary-adrenal (HPA) axis. The mismatches in temporal characteristic and the indices of hair and salivary cortisol might be potential reasons for the inconsistency. The aim of this study was to investigate the consistency between hair and salivary levels in cortisol and cortisone by directly examining the correlation between hair level and salivary level with different temporal characteristics (acute, short-term and long-term levels) and reflecting different HPA functions (basal level and reactivity level) in the well-matched time span. A longitudinal design within a five-week period was conducted in a sample of 44 healthy female college students (mean age: 18.8yrs.; age range: 18-22yrs) of Han nationality with the exclusion criteria, such as use of oral contraceptives or glucocorticoids and bleached hairs, etc. Four saliva samples (awakening, awakening+30min, awakening+4h and awakening+9h) were collected from an identical participant on three separate days with an interval of one week and 1-cm hair segment nearest to the scalp was collected two weeks later after completing saliva collection. Cortisol and cortisone in saliva and hair were simultaneously measured with high performance liquid chromatography tandem mass spectrometry. There were significantly moderate correlations in cortisol and cortisone between hair level and three-day average of single-day salivary level, but low to moderate correlations between hair level and single-point and single-day salivary level. Hair cortisol and cortisone were unrelated to single-day level and three-day average of diurnal slope and cortisol awakening response of salivary cortisol and cortisone, respectively. The considerable consistency between hair level and long-term salivary level in cortisol and cortisone implies that cortisol and cortisone in hair are valid biomarkers of

Integrative Spatial Data Analytics for Public Health Studies of New York State.

Science.gov (United States)

Chen, Xin; Wang, Fusheng

2016-01-01

Increased accessibility of health data made available by the government provides unique opportunity for spatial analytics with much higher resolution to discover patterns of diseases, and their correlation with spatial impact indicators. This paper demonstrated our vision of integrative spatial analytics for public health by linking the New York Cancer Mapping Dataset with datasets containing potential spatial impact indicators. We performed spatial based discovery of disease patterns and variations across New York State, and identify potential correlations between diseases and demographic, socio-economic and environmental indicators. Our methods were validated by three correlation studies: the correlation between stomach cancer and Asian race, the correlation between breast cancer and high education population, and the correlation between lung cancer and air toxics. Our work will allow public health researchers, government officials or other practitioners to adequately identify, analyze, and monitor health problems at the community or neighborhood level for New York State.

Using the Normalized Differential Wetness Index to Scale Leaf Area Index, Create Three-Dimensional Classification Maps, and Scale Seasonal Evapotranspiration Depletions in Canopies Along the Middle Rio Grande Riparian CorridorCorridor

Science.gov (United States)

McDonnell, D. E.; Cleverly, J. R.; Dahm, C. N.; Coonrod, J. A.

2005-12-01

This research creates temporally and spatially explicit data layers of vegetation, leaf area index (LAI), three dimensional (3D) vegetation classification maps, and seasonal evapotranspiration (ET) depletions along the middle Rio Grande riparian corridor. The first part of this work produces two dimensional (2D) classification maps of native and non-native canopy vegetation using temporal patterns and the decision tree classifier in ENVI 4.0 (Research Systems Inc. Boulder, Colorado). The second part of this work correlates the normalized differential wetness index (NDWI) with field measurements of plant area index (PAI), stem area index (SAI), and leaf area index (LAI) using the LAI-2000 Plant Canopy Analyzer (PCA) (LICOR Inc., Lincoln, Nebraska). SAI is measured in winter to capture only branches and stems. PAI is measured during the growing season. Field measurements taken within 10 days of image capture dates provide adequate correlations though the closer the dates the better the correlation. LAI represents the surface area of active green leafy vegetation. NDWI correlates with both PAI and estimated LAI in both Tamarisk chinensis and Populus deltoides ssp. Wislizeni sites better than the more traditional normalized differential vegetation index (NDVI). This study also suggests that winter PCA measurements approximate SAI which should be subtracted from PAI in woody vegetation like T. chinensis and Salix exigua stands. The results show that correcting for leaf geometry by multiplying T. chinensis areas with cylindrical cladophylls by pi and the remaining flat leaf vegetation by two yields the best relationship between NDWI and total LAI. The 2Dclassification maps can be placed on top of relief maps of LAI to produce 3D classification maps. The final part of this research scales ET from four 3D eddy covariance towers located in two T. chinensis and two P. deltoides study sites. ET is regressed with LAI, percent daylight (PD), and average hourly incoming net

Ray-Based Statistical Propagation Modeling for Indoor Corridor Scenarios at 15 GHz

Directory of Open Access Journals (Sweden)

Qi Wang

2016-01-01

Full Text Available According to the demands for fifth-generation (5G communication systems, high frequency bands (above 6 GHz need to be adopted to provide additional spectrum. This paper investigates the characteristics of indoor corridor channels at 15 GHz. Channel measurements with a vector network analyzer in two corridors were conducted. Based on a ray-optical approach, a deterministic channel model covering both antenna and propagation characteristic is presented. The channel model is evaluated by comparing simulated results of received power and root mean square delay spread with the corresponding measurements. By removing the impact of directional antennas from the transmitter and receiver, a path loss model as well as small-scale fading properties for typical corridors is presented based on the generated samples from the deterministic model. Results show that the standard deviation of path loss variation is related to the Tx height, and placing the Tx closer to the ceiling leads to a smaller fluctuation of path loss.

76 FR 65561 - Multistate Corridor Operations and Management Program

Science.gov (United States)

2011-10-21

... participation in the Multistate Corridor Operations and Management (MCOM) Program authorized by the Safe... transportation system management and operations. This notice seeks applications for available fiscal year (FY... system management and operations. Since the MCOM program is funded by the DOT Intelligent Transportation...

Spatial Organization and Molecular Correlation of Tumor-Infiltrating Lymphocytes Using Deep Learning on Pathology Images

Directory of Open Access Journals (Sweden)

Joel Saltz

2018-04-01

Full Text Available Summary: Beyond sample curation and basic pathologic characterization, the digitized H&E-stained images of TCGA samples remain underutilized. To highlight this resource, we present mappings of tumor-infiltrating lymphocytes (TILs based on H&E images from 13 TCGA tumor types. These TIL maps are derived through computational staining using a convolutional neural network trained to classify patches of images. Affinity propagation revealed local spatial structure in TIL patterns and correlation with overall survival. TIL map structural patterns were grouped using standard histopathological parameters. These patterns are enriched in particular T cell subpopulations derived from molecular measures. TIL densities and spatial structure were differentially enriched among tumor types, immune subtypes, and tumor molecular subtypes, implying that spatial infiltrate state could reflect particular tumor cell aberration states. Obtaining spatial lymphocytic patterns linked to the rich genomic characterization of TCGA samples demonstrates one use for the TCGA image archives with insights into the tumor-immune microenvironment. : Tumor-infiltrating lymphocytes (TILs were identified from standard pathology cancer images by a deep-learning-derived “computational stain” developed by Saltz et al. They processed 5,202 digital images from 13 cancer types. Resulting TIL maps were correlated with TCGA molecular data, relating TIL content to survival, tumor subtypes, and immune profiles. Keywords: digital pathology, immuno-oncology, machine learning, lymphocytes, tumor microenvironment, deep learning, tumor-infiltrating lymphocytes, artificial intelligence, bioinformatics, computer vision

Designs of Optoelectronic Trinary Signed-Digit Multiplication by use of Joint Spatial Encodings and Optical Correlation

Science.gov (United States)

Cherri, Abdallah K.

1999-02-01

Trinary signed-digit (TSD) symbolic-substitution-based (SS-based) optical adders, which were recently proposed, are used as the basic modules for designing highly parallel optical multiplications by use of cascaded optical correlators. The proposed multiplications perform carry-free generation of the multiplication partial products of two words in constant time. Also, three different multiplication designs are presented, and new joint spatial encodings for the TSD numbers are introduced. The proposed joint spatial encodings allow one to reduce the SS computation rules involved in optical multiplication. In addition, the proposed joint spatial encodings increase the space bandwidth product of the spatial light modulators of the optical system. This increase is achieved by reduction of the numbers of pixels in the joint spatial encodings for the input TSD operands as well as reduction of the number of pixels used in the proposed matched spatial filters for the optical multipliers.

A Climatology of Derecho-Producing Mesoscale Convective Systems in the Central and Eastern United States, 1986-95. Part I: Temporal and Spatial Distribution.

Science.gov (United States)

Bentley, Mace L.; Mote, Thomas L.

1998-11-01

In 1888, Iowa weather researcher Gustavus Hinrichs gave widespread convectively induced windstorms the name "derecho". Refinements to this definition have evolved after numerous investigations of these systems; however, to date, a derecho climatology has not been conducted.This investigation examines spatial and temporal aspects of derechos and their associated mesoscale convective systems that occurred from 1986 to 1995. The spatial distribution of derechos revealed four activity corridors during the summer, five during the spring, and two during the cool season. Evidence suggests that the primary warm season derecho corridor is located in the southern Great Plains. During the cool season, derecho activity was found to occur in the southeast states and along the Atlantic seaboard. Temporally, derechos are primarily late evening or overnight events during the warm season and are more evenly distributed throughout the day during the cool season.

A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management

Directory of Open Access Journals (Sweden)

Tianxin Li

2015-10-01

Full Text Available Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = −0.8267, p = 0.0017 and CAT (r = −0.89, p = 0.0002 activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants.

Influence of the freight transnational rail liner service on the train scheduling in case of major corridors

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Mihaela POPA

2013-01-01

Full Text Available In this paper we discuss several consequences of the freight transnational rail liner service on the rail corridor capacity. The Northern part of the IVth TEN-T corridor on Romanian territory has specific feature related to the passenger flows connecting important Romanian demographic and economic clusters, on one side, and on the other side, to its diagonal crossing aspect, from the Western border to the Constanta port, connecting the Central Europe countries to the Black Sea regions, which means that there are a lot of expectation in terms of this corridor rail capacity: this corridor will, be for a long time further, the single and first completed continuous upgraded and modernised rail corridor. Its utilization will necessarily be heterogeneously planned (meaning for passengers rapid trains and freight rapid trains, from domestic/internal market, but especially for external market of Romania. In this paper, we consider a simple mathematical model for the calculus of capacity in two different cases: for a homogeneous utilization, meaning that all trains have the same running speeds and for heterogeneous utilization, when the passenger trains have the higher speed and hence, the higher priority over the freight trains, even if some of them are freight transnational liner service. Special feature of liner rail service has to be considered (fixed schedule, no stops for passenger train advance. We draw several useful possible solutions to be considered in order to preserve the active corridor capacity, and to assure a smooth flow for the transnational liner services, which ultimately will enhance the rail attractiveness.

Performance evaluation of concrete railroad ties on the northeast corridor.

Science.gov (United States)

2014-03-01

Simpson Gumpertz & Heger Inc. conducted an investigation into the factors that caused widespread failure in prestressed concrete : railroad ties on the Northeast Corridor. The problem was apparent in ties manufactured and installed circa 19941998....

A landscape perspective of the stream corridor invasion and habitat characteristics of an exotic (Dioscorea oppositifolia) in a pristine watershed in Illinois

Science.gov (United States)

Thomas, J.R.; Middleton, B.; Gibson, D.J.

2006-01-01

The spatial distribution of exotics across riparian landscapes is not uniform, and research elaborating the environmental constraints and dispersal behavior that underlie these patterns of distribution is warranted. This study examined the spatial distribution, growth patterns, and habitat constraints of populations of the invasive Dioscorea oppositifolia in a forested stream corridor of a tributary of Drury Creek in Giant City State Park, IL. The distribution of D. oppositifolia was determined at the watershed scale mainly by floodplain structure and connectivity. Populations of D. oppositifolia were confined to the floodplain, with overbank flooding from the stream. Dioscorea oppositifolia probably originates in disturbed areas upstream of natural corridors, and subsequently, the species disperses downstream into pristine canyons or ravines via bulbils dispersing in the water. In Giant City State Park, populations of D. oppositifolia were distributed on the floodplain across broad gradients of soil texture, light, slope, and potential radiation. The study also examined the longevity of bulbils in various micro-environments to illuminate strategies for the management of the species in invaded watersheds. After 1 year, the highest percentages of bulbils were viable under leaves, and much lower percentages were viable over leaves, in soil, and in the creek (76.0??6.8, 21.2??9.6, 21.6??3.6, and 5.2??5.2%), respectively. This study suggests that management procedures that reduce leaf litter on the forest floor (e.g., prescribed burning) could reduce the number of bulbils of D. oppositifolia stored in the watershed. ?? Springer 2006.

Soil erosion evolution and spatial correlation analysis in a typical karst geomorphology using RUSLE with GIS

Science.gov (United States)

Zeng, Cheng; Wang, Shijie; Bai, Xiaoyong; Li, Yangbing; Tian, Yichao; Li, Yue; Wu, Luhua; Luo, Guangjie

2017-07-01

Although some scholars have studied soil erosion in karst landforms, analyses of the spatial and temporal evolution of soil erosion and correlation analyses with spatial elements have been insufficient. The lack of research has led to an inaccurate assessment of environmental effects, especially in the mountainous area of Wuling in China. Soil erosion and rocky desertification in this area influence the survival and sustainability of a population of 0.22 billion people. This paper analyzes the spatiotemporal evolution of soil erosion and explores its relationship with rocky desertification using GIS technology and the revised universal soil loss equation (RUSLE). Furthermore, this paper analyzes the relationship between soil erosion and major natural elements in southern China. The results are as follows: (1) from 2000 to 2013, the proportion of the area experiencing micro-erosion and mild erosion was at increasing risk in contrast to areas where moderate and high erosion are decreasing. The area changes in this time sequence reflect moderate to high levels of erosion tending to convert into micro-erosion and mild erosion. (2) The soil erosion area on the slope, at 15-35°, accounted for 60.59 % of the total erosion area, and the corresponding soil erosion accounted for 40.44 %. (3) The annual erosion rate in the karst region decreased much faster than in the non-karst region. Soil erosion in all of the rock outcrop areas indicates an improving trend, and dynamic changes in soil erosion significantly differ among the various lithological distribution belts. (4) The soil erosion rate decreased in the rocky desertification regions, to below moderate levels, but increased in the severe rocky desertification areas. The temporal and spatial variations in soil erosion gradually decreased in the study area. Differences in the spatial distribution between lithology and rocky desertification induced extensive soil loss. As rocky desertification became worse, the erosion

Soil erosion evolution and spatial correlation analysis in a typical karst geomorphology using RUSLE with GIS

Directory of Open Access Journals (Sweden)

C. Zeng

2017-07-01

Full Text Available Although some scholars have studied soil erosion in karst landforms, analyses of the spatial and temporal evolution of soil erosion and correlation analyses with spatial elements have been insufficient. The lack of research has led to an inaccurate assessment of environmental effects, especially in the mountainous area of Wuling in China. Soil erosion and rocky desertification in this area influence the survival and sustainability of a population of 0.22 billion people. This paper analyzes the spatiotemporal evolution of soil erosion and explores its relationship with rocky desertification using GIS technology and the revised universal soil loss equation (RUSLE. Furthermore, this paper analyzes the relationship between soil erosion and major natural elements in southern China. The results are as follows: (1 from 2000 to 2013, the proportion of the area experiencing micro-erosion and mild erosion was at increasing risk in contrast to areas where moderate and high erosion are decreasing. The area changes in this time sequence reflect moderate to high levels of erosion tending to convert into micro-erosion and mild erosion. (2 The soil erosion area on the slope, at 15–35°, accounted for 60.59 % of the total erosion area, and the corresponding soil erosion accounted for 40.44 %. (3 The annual erosion rate in the karst region decreased much faster than in the non-karst region. Soil erosion in all of the rock outcrop areas indicates an improving trend, and dynamic changes in soil erosion significantly differ among the various lithological distribution belts. (4 The soil erosion rate decreased in the rocky desertification regions, to below moderate levels, but increased in the severe rocky desertification areas. The temporal and spatial variations in soil erosion gradually decreased in the study area. Differences in the spatial distribution between lithology and rocky desertification induced extensive soil loss. As rocky desertification

Spatial dependence and correlation of rainfall in the Danube catchment and its role in flood risk assessment.

Science.gov (United States)

Martina, M. L. V.; Vitolo, R.; Todini, E.; Stephenson, D. B.; Cook, I. M.

2009-04-01

The possibility that multiple catastrophic events occur within a given timespan and affect the same portfolio of insured properties may induce enhanced risk. For this reason, in the insurance industry it is of interest to characterise not only the point probability of catastrophic events, but also their spatial structure. As far as floods are concerned it is important to determine the probability of having multiple simultaneous events in different parts of the same basin: in this case, indeed, the loss in a portfolio can be significantly different. Understanding the spatial structure of the precipitation field is a necessary step for the proper modelling of the spatial dependence and correlation of river discharge. Several stochastic models are available in the scientific literature for the multi-site generation of precipitation. Although most models achieve good performance in modelling mean values, temporal variability and inter-site dependence of extremes are still delicate issues. In this work we aim at identifying the main spatial characteristics of the precipitation structure and then at analysing them in a real case. We consider data from a large network of raingauges in the Danube catchment. This catchment is a good example of a large-scale catchment where the spatial correlation of flood events can radically change the effect in term of flood damage.

Thermal Comfort At The Street Corridor Around Public Places, Case Study Alun-Alun Malang City

Directory of Open Access Journals (Sweden)

Erna Winansih

2016-01-01

Full Text Available Malang as the second largest city in East Java province become crowded recently. The congestion almost happens everyday. The scenery of the street corridor is full of iron stacks. It is said that Malang city is less comfortable and less walkable. The decrease of this environment encourages to conduct the study (Q.S. 16:90, Q.S. 96:1-5, Q.S. 30:41. The study aimed to analyze the thermal comfort at pedestrian ways around Malang city squares, the street corridor of Merdeka Alun-Alun (MAA and the Tugu Alun-Alun (TAA. The temperature and relative humidity were measured by multinorm instrument. The THI (Temperature Humidity Index method was used to analyze the thermal comfort. The results showed that the THI average at TAA (27 were more comfortable than at MAA (27,5. The south side of the MAA corridor became the most comfortable with the THI value of 26,4, which the side covered by trees canopy (Q.S. 7:58. It needs to conduct next research (Q.S. 13:11, because of the change of the activities at these street corridors.

Mobile Robot Navigation in a Corridor Using Visual Odometry

DEFF Research Database (Denmark)

Bayramoglu, Enis; Andersen, Nils Axel; Poulsen, Niels Kjølstad

2009-01-01

Incorporation of computer vision into mobile robot localization is studied in this work. It includes the generation of localization information from raw images and its fusion with the odometric pose estimation. The technique is then implemented on a small mobile robot operating at a corridor...

Database on Aims and Visions in the COINCO Corridor

DEFF Research Database (Denmark)

2005-01-01

This database contains aims and visions regarding overall regional development as well as more specific aims and visions related to transport and infrastructure in the Corridor Oslo-Göteborg-Copenhagen-Berlin. The sources used for this database are the most essential planning documents from Denmark...

Detecting subnetwork-level dynamic correlations.

Science.gov (United States)

Yan, Yan; Qiu, Shangzhao; Jin, Zhuxuan; Gong, Sihong; Bai, Yun; Lu, Jianwei; Yu, Tianwei

2017-01-15

The biological regulatory system is highly dynamic. The correlations between many functionally related genes change over different biological conditions. Finding dynamic relations on the existing biological network may reveal important regulatory mechanisms. Currently no method is available to detect subnetwork-level dynamic correlations systematically on the genome-scale network. Two major issues hampered the development. The first is gene expression profiling data usually do not contain time course measurements to facilitate the analysis of dynamic relations, which can be partially addressed by using certain genes as indicators of biological conditions. Secondly, it is unclear how to effectively delineate subnetworks, and define dynamic relations between them. Here we propose a new method named LANDD (Liquid Association for Network Dynamics Detection) to find subnetworks that show substantial dynamic correlations, as defined by subnetwork A is concentrated with Liquid Association scouting genes for subnetwork B. The method produces easily interpretable results because of its focus on subnetworks that tend to comprise functionally related genes. Also, the collective behaviour of genes in a subnetwork is a much more reliable indicator of underlying biological conditions compared to using single genes as indicators. We conducted extensive simulations to validate the method's ability to detect subnetwork-level dynamic correlations. Using a real gene expression dataset and the human protein-protein interaction network, we demonstrate the method links subnetworks of distinct biological processes, with both confirmed relations and plausible new functional implications. We also found signal transduction pathways tend to show extensive dynamic relations with other functional groups. The R package is available at https://cran.r-project.org/web/packages/LANDD CONTACTS: yunba@pcom.edu, jwlu33@hotmail.com or tianwei.yu@emory.eduSupplementary information: Supplementary data

Permafrost Distribution along the Qinghai-Tibet Engineering Corridor, China Using High-Resolution Statistical Mapping and Modeling Integrated with Remote Sensing and GIS

Directory of Open Access Journals (Sweden)

Fujun Niu

2018-02-01

Full Text Available Permafrost distribution in the Qinghai-Tibet Engineering Corridor (QTEC is of growing interest due to the increase in infrastructure development in this remote area. Empirical models of mountain permafrost distribution have been established based on field sampled data, as a tool for regional-scale assessments of its distribution. This kind of model approach has never been applied for a large portion of this engineering corridor. In the present study, this methodology is applied to map permafrost distribution throughout the QTEC. After spatial modelling of the mean annual air temperature distribution from MODIS-LST and DEM, using high-resolution satellite image to interpret land surface type, a permafrost probability index was obtained. The evaluation results indicate that the model has an acceptable performance. Conditions highly favorable to permafrost presence (≥70% are predicted for 60.3% of the study area, declaring a discontinuous permafrost distribution in the QTEC. This map is useful for the infrastructure development along the QTEC. In the future, local ground-truth observations will be required to confirm permafrost presence in favorable areas and to monitor permafrost evolution under the influence of climate change.

Spatially resolved D-T(2) correlation NMR of porous media.

Science.gov (United States)

Zhang, Yan; Blümich, Bernhard

2014-05-01

Within the past decade, 2D Laplace nuclear magnetic resonance (NMR) has been developed to analyze pore geometry and diffusion of fluids in porous media on the micrometer scale. Many objects like rocks and concrete are heterogeneous on the macroscopic scale, and an integral analysis of microscopic properties provides volume-averaged information. Magnetic resonance imaging (MRI) resolves this spatial average on the contrast scale set by the particular MRI technique. Desirable contrast parameters for studies of fluid transport in porous media derive from the pore-size distribution and the pore connectivity. These microscopic parameters are accessed by 1D and 2D Laplace NMR techniques. It is therefore desirable to combine MRI and 2D Laplace NMR to image functional information on fluid transport in porous media. Because 2D Laplace resolved MRI demands excessive measuring time, this study investigates the possibility to restrict the 2D Laplace analysis to the sum signals from low-resolution pixels, which correspond to pixels of similar amplitude in high-resolution images. In this exploratory study spatially resolved D-T2 correlation maps from glass beads and mortar are analyzed. Regions of similar contrast are first identified in high-resolution images to locate corresponding pixels in low-resolution images generated with D-T2 resolved MRI for subsequent pixel summation to improve the signal-to-noise ratio of contrast-specific D-T2 maps. This method is expected to contribute valuable information on correlated sample heterogeneity from the macroscopic and the microscopic scales in various types of porous materials including building materials and rock. Copyright © 2014 Elsevier Inc. All rights reserved.

Frequency and Wavevector Dependence of the Atomic Level Stress-Stress Correlation Function in a Model Supercooled Liquid

Science.gov (United States)

Levashov, Valentin A.; Morris, James R.; Egami, Takeshi

2012-02-01

Temporal and spatial correlations among the local atomic level shear stresses were studied for a model liquid iron by molecular dynamics simulation [PRL 106,115703]. Integration over time and space of the shear stress correlation function F(r,t) yields viscosity via Green-Kubo relation. The stress correlation function in time and space F(r,t) was Fourier transformed to study the dependence on frequency, E, and wave vector, Q. The results, F(Q,E), showed damped shear stress waves propagating in the liquid for small Q at high and low temperatures. We also observed additional diffuse feature that appears as temperature is reduced below crossover temperature of potential energy landscape at relatively low frequencies at small Q. We suggest that this additional feature might be related to dynamic heterogeneity and boson peaks. We also discuss a relation between the time-scale of the stress-stress correlation function and the alpha-relaxation time of the intermediate self-scattering function S(Q,E).

Parametric level correlations in random-matrix models

International Nuclear Information System (INIS)

Weidenmueller, Hans A

2005-01-01

We show that parametric level correlations in random-matrix theories are closely related to a breaking of the symmetry between the advanced and the retarded Green functions. The form of the parametric level correlation function is the same as for the disordered case considered earlier by Simons and Altshuler and is given by the graded trace of the commutator of the saddle-point solution with the particular matrix that describes the symmetry breaking in the actual case of interest. The strength factor differs from the case of disorder. It is determined solely by the Goldstone mode. It is essentially given by the number of levels that are strongly mixed as the external parameter changes. The factor can easily be estimated in applications

Hot Spots and Hot Times: Wildlife Road Mortality in a Regional Conservation Corridor

Science.gov (United States)

Garrah, Evelyn; Danby, Ryan K.; Eberhardt, Ewen; Cunnington, Glenn M.; Mitchell, Scott

2015-10-01

Strategies to reduce wildlife road mortality have become a significant component of many conservation efforts. However, their success depends on knowledge of the temporal and spatial patterns of mortality. We studied these patterns along the 1000 Islands Parkway in Ontario, Canada, a 37 km road that runs adjacent to the St. Lawrence River and bisects the Algonquin-to-Adirondacks international conservation corridor. Characteristics of all vertebrate road kill were recorded during 209 bicycle surveys conducted from 2008 to 2011. We estimate that over 16,700 vertebrates are killed on the road from April to October each year; most are amphibians, but high numbers of birds, mammals, and reptiles were also found, including six reptiles considered at-risk in Canada. Regression tree analysis was used to assess the importance of seasonality, weather, and traffic on road kill magnitude. All taxa except mammals exhibited distinct temporal peaks corresponding to phases in annual life cycles. Variations in weather and traffic were only important outside these peak times. Getis-Ord analysis was used to identify spatial clusters of mortality. Hot spots were found in all years for all taxa, but locations varied annually. A significant spatial association was found between multiyear hot spots and wetlands. The results underscore the notion that multi-species conservation efforts must account for differences in the seasonality of road mortality among species and that multiple years of data are necessary to identify locations where the greatest conservation good can be achieved. This information can be used to inform mitigation strategies with implications for conservation at regional scales.

Spatial correlations of Diceroprocta apache and its host plants: Evidence for a negative impact from Tamarix invasion

Science.gov (United States)

Ellingson, A.R.; Andersen, D.C.

2002-01-01

1. The hypothesis that the habitat-scale spatial distribution of the Apache cicada Diceroprocta apache Davis is unaffected by the presence of the invasive exotic saltcedar Tamarix ramosissima was tested using data from 205 1-m2 quadrats placed within the flood-plain of the Bill Williams River, Arizona, U.S.A. Spatial dependencies within and between cicada density and habitat variables were estimated using Moran's I and its bivariate analogue to discern patterns and associations at spatial scales from 1 to 30 m.2. Apache cicadas were spatially aggregated in high-density clusters averaging 3 m in diameter. A positive association between cicada density, estimated by exuvial density, and the per cent canopy cover of a native tree, Goodding's willow Salix gooddingii, was detected in a non-spatial correlation analysis. No non-spatial association between cicada density and saltcedar canopy cover was detected.3. Tests for spatial cross-correlation using the bivariate IYZ indicated the presence of a broad-scale negative association between cicada density and saltcedar canopy cover. This result suggests that large continuous stands of saltcedar are associated with reduced cicada density. In contrast, positive associations detected at spatial scales larger than individual quadrats suggested a spill-over of high cicada density from areas featuring Goodding's willow canopy into surrounding saltcedar monoculture.4. Taken together and considered in light of the Apache cicada's polyphagous habits, the observed spatial patterns suggest that broad-scale factors such as canopy heterogeneity affect cicada habitat use more than host plant selection. This has implications for management of lower Colorado River riparian woodlands to promote cicada presence and density through maintenance or creation of stands of native trees as well as manipulation of the characteristically dense and homogeneous saltcedar canopies.

Building Coverage Ratio at the Eastern Corridor of Jalan Ir. H. Djuanda Bandung

Science.gov (United States)

Megayanti, T.; Widaningsih, L.; Minggra, R.; Dewi, N. I. K.

2018-01-01

Historically in the Colonial period, the Corridor of Jalan Ir. H. Juanda or better known as Jalan Dago was designed as a residential area. As the high development of commercial activity along of Bandung City, almost all of buildings in this area are turned its’ function to supported commercial activity. The change is shown in many aspects from the shape of the building and even occur in changing the old building into a new one due to a high intensity of this commercial activity. This paper investigates the use of Building Coverage Ratio regulation related to functional change in the Corridor of Jalan Ir. H. Juanda Bandung. The aim is to what extent the regulations related to Building Coverage area are implemented. This study used a descriptive qualitative method by conducting observation to identify buildings on the Corridor by dividing it into three segments. The results show quantitatively there is a lot of irrelevancies to Building Coverage Ratio regulation which is shown in the second and third segment. Most of the building in the first segment has in compliance with the regulation. However, to build a harmony in characters of City corridor is not only created by Building Coverage Ratio but also others parameters such as the land use, the shape of buildings, façade, and design concept. Thus, it is highly recommended to create a detail regulation regarding those parameters.

Sea-level changes on multiple spatial scales: estimates and contributing processes

NARCIS (Netherlands)

Frederikse, T.

2018-01-01

Being one of the major consequences of anthropogenic climate change, sea level rise forms a threat for many coastal areas and their inhabitants. Because all processes that cause sea-level changes have a spatially-varying fingerprint, local sea-level changes deviate substantially from the global

Discrete capacity limits and neuroanatomical correlates of visual short-term memory for objects and spatial locations.

Science.gov (United States)

Konstantinou, Nikos; Constantinidou, Fofi; Kanai, Ryota

2017-02-01

Working memory is responsible for keeping information in mind when it is no longer in view, linking perception with higher cognitive functions. Despite such crucial role, short-term maintenance of visual information is severely limited. Research suggests that capacity limits in visual short-term memory (VSTM) are correlated with sustained activity in distinct brain areas. Here, we investigated whether variability in the structure of the brain is reflected in individual differences of behavioral capacity estimates for spatial and object VSTM. Behavioral capacity estimates were calculated separately for spatial and object information using a novel adaptive staircase procedure and were found to be unrelated, supporting domain-specific VSTM capacity limits. Voxel-based morphometry (VBM) analyses revealed dissociable neuroanatomical correlates of spatial versus object VSTM. Interindividual variability in spatial VSTM was reflected in the gray matter density of the inferior parietal lobule. In contrast, object VSTM was reflected in the gray matter density of the left insula. These dissociable findings highlight the importance of considering domain-specific estimates of VSTM capacity and point to the crucial brain regions that limit VSTM capacity for different types of visual information. Hum Brain Mapp 38:767-778, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Using 3D spatial correlations to improve the noise robustness of multi component analysis of 3D multi echo quantitative T2 relaxometry data.

Science.gov (United States)

Kumar, Dushyant; Hariharan, Hari; Faizy, Tobias D; Borchert, Patrick; Siemonsen, Susanne; Fiehler, Jens; Reddy, Ravinder; Sedlacik, Jan

2018-05-12

We present a computationally feasible and iterative multi-voxel spatially regularized algorithm for myelin water fraction (MWF) reconstruction. This method utilizes 3D spatial correlations present in anatomical/pathological tissues and underlying B1 + -inhomogeneity or flip angle inhomogeneity to enhance the noise robustness of the reconstruction while intrinsically accounting for stimulated echo contributions using T2-distribution data alone. Simulated data and in vivo data acquired using 3D non-selective multi-echo spin echo (3DNS-MESE) were used to compare the reconstruction quality of the proposed approach against those of the popular algorithm (the method by Prasloski et al.) and our previously proposed 2D multi-slice spatial regularization spatial regularization approach. We also investigated whether the inter-sequence correlations and agreements improved as a result of the proposed approach. MWF-quantifications from two sequences, 3DNS-MESE vs 3DNS-gradient and spin echo (3DNS-GRASE), were compared for both reconstruction approaches to assess correlations and agreements between inter-sequence MWF-value pairs. MWF values from whole-brain data of six volunteers and two multiple sclerosis patients are being reported as well. In comparison with competing approaches such as Prasloski's method or our previously proposed 2D multi-slice spatial regularization method, the proposed method showed better agreements with simulated truths using regression analyses and Bland-Altman analyses. For 3DNS-MESE data, MWF-maps reconstructed using the proposed algorithm provided better depictions of white matter structures in subcortical areas adjoining gray matter which agreed more closely with corresponding contrasts on T2-weighted images than MWF-maps reconstructed with the method by Prasloski et al. We also achieved a higher level of correlations and agreements between inter-sequence (3DNS-MESE vs 3DNS-GRASE) MWF-value pairs. The proposed algorithm provides more noise

Diffuse correlation tomography reveals spatial and temporal difference in blood flow changes among murine femoral grafts

Science.gov (United States)

Han, Songfeng; Proctor, Ashley R.; Benoit, Danielle S. W.; Choe, Regine

2017-07-01

Diffuse correlation tomography was utilized to noninvasively monitor 3D blood flow changes in three types of healing mouse femoral grafts. Results reveal the spatial and temporal difference among the groups.

Multi-Modal Traveler Information System - GCM Corridor Architecture Functional Requirements

Science.gov (United States)

1997-11-17

The Multi-Modal Traveler Information System (MMTIS) project involves a large number of Intelligent Transportation System (ITS) related tasks. It involves research of all ITS initiatives in the Gary-Chicago-Milwaukee (GCM) Corridor which are currently...

The spatial distribution of LGR5+ cells correlates with gastric cancer progression.

Directory of Open Access Journals (Sweden)

Eva Simon

Full Text Available In this study we tested the prevalence, histoanatomical distribution and tumour biological significance of the Wnt target protein and cancer stem cell marker LGR5 in tumours of the human gastrointestinal tract. Differential expression of LGR5 was studied on transcriptional (real-time polymerase chain reaction and translational level (immunohistochemistry in malignant and corresponding non-malignant tissues of 127 patients comprising six different primary tumour sites, i.e. oesophagus, stomach, liver, pancreas, colon and rectum. The clinico-pathological significance of LGR5 expression was studied in 100 patients with gastric carcinoma (GC. Non-neoplastic tissue usually harboured only very few scattered LGR5(+ cells. The corresponding carcinomas of the oesophagus, stomach, liver, pancreas, colon and rectum showed significantly more LGR5(+ cells as well as significantly higher levels of LGR5-mRNA compared with the corresponding non-neoplastic tissue. Double staining experiments revealed a coexpression of LGR5 with the putative stem cell markers CD44, Musashi-1 and ADAM17. Next we tested the hypothesis that the sequential changes of gastric carcinogenesis, i.e. chronic atrophic gastritis, intestinal metaplasia and invasive carcinoma, are associated with a reallocation of the LGR5(+ cells. Interestingly, the spatial distribution of LGR5 changed: in non-neoplastic stomach mucosa, LGR5(+ cells were found predominantly in the mucous neck region; in intestinal metaplasia LGR5(+ cells were localized at the crypt base, and in GC LGR5(+ cells were present at the luminal surface, the tumour centre and the invasion front. The expression of LGR5 in the tumour centre and invasion front of GC correlated significantly with the local tumour growth (T-category and the nodal spread (N-category. Furthermore, patients with LGR5(+ GCs had a shorter median survival (28.0±8.6 months than patients with LGR5(- GCs (54.5±6.3 months. Our results show that LGR5 is

The analog computation and contrast test of leaked electromagnetic noise in the klystron corridor

International Nuclear Information System (INIS)

Tao Xiaoping; Wang Guicheng

2001-01-01

In order to obtain a better understand of the characteristics and location of noise source, the leaked electromagnetic noise in the klystron corridor of NSRL has been analogously calculated. The computational method and formula of high frequency leaked noise of the modulator were given. On-the-spot contrast tests have been made on the base of analog computation. The contrast test results show reasonableness of analog computation and whereby offer a theoretic base for reducing noise leakage in corridor

The Comoros Show the Earliest Austronesian Gene Flow into the Swahili Corridor.

Science.gov (United States)

Brucato, Nicolas; Fernandes, Veronica; Mazières, Stéphane; Kusuma, Pradiptajati; Cox, Murray P; Ng'ang'a, Joseph Wainaina; Omar, Mohammed; Simeone-Senelle, Marie-Claude; Frassati, Coralie; Alshamali, Farida; Fin, Bertrand; Boland, Anne; Deleuze, Jean-Francois; Stoneking, Mark; Adelaar, Alexander; Crowther, Alison; Boivin, Nicole; Pereira, Luisa; Bailly, Pascal; Chiaroni, Jacques; Ricaut, François-Xavier

2018-01-04

At the dawn of the second millennium, the expansion of the Indian Ocean trading network aligned with the emergence of an outward-oriented community along the East African coast to create a cosmopolitan cultural and trading zone known as the Swahili Corridor. On the basis of analyses of new genome-wide genotyping data and uniparental data in 276 individuals from coastal Kenya and the Comoros islands, along with large-scale genetic datasets from the Indian Ocean rim, we reconstruct historical population dynamics to show that the Swahili Corridor is largely an eastern Bantu genetic continuum. Limited gene flows from the Middle East can be seen in Swahili and Comorian populations at dates corresponding to historically documented contacts. However, the main admixture event in southern insular populations, particularly Comorian and Malagasy groups, occurred with individuals from Island Southeast Asia as early as the 8 th century, reflecting an earlier dispersal from this region. Remarkably, our results support recent archaeological and linguistic evidence-based suggestions that the Comoros archipelago was the earliest location of contact between Austronesian and African populations in the Swahili Corridor. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

River-corridor habitat dynamics, Lower Missouri River

Science.gov (United States)

Jacobson, Robert B.

2010-01-01

Intensive management of the Missouri River for navigation, flood control, and power generation has resulted in substantial physical changes to the river corridor. Historically, the Missouri River was characterized by a shifting, multithread channel and abundant unvegetated sandbars. The shifting channel provided a wide variety of hydraulic environments and large areas of connected and unconnected off-channel water bodies.Beginning in the early 1800s and continuing to the present, the channel of the Lower Missouri River (downstream from Sioux City, Iowa) has been trained into a fast, deep, single-thread channel to stabilize banks and maintain commercial navigation. Wing dikes now concentrate the flow, and revetments and levees keep the channel in place and disconnect it from the flood plain. In addition, reservoir regulation of the Missouri River upstream of Yankton, South Dakota, has substantially changed the annual hydrograph, sediment loads, temperature regime, and nutrient budgets.While changes to the Missouri River have resulted in broad social and economic benefits, they have also been associated with loss of river-corridor habitats and diminished populations of native fish and wildlife species. Today, Missouri River stakeholders are seeking ways to restore some natural ecosystem benefits of the Lower Missouri River without compromising traditional economic uses of the river and flood plain.

Early environmental planning: A process for power line corridor selection

International Nuclear Information System (INIS)

Haagenstad, T.; Bare, C.M.

1998-01-01

Los Alamos National Laboratory (LANL) conducted an environmental planning study in the fall of 1997 to help determine the best alternative for upgrading the Laboratory's electrical power system. Alternatives considered included an on-site power generation facility and two corridors for a 10-mile-long 115-kV power line. This planning process was conducted prior to the formal National Environmental Policy Act (NEPA) review. The goals were to help select the best proposed action, to recommend modifications and mitigation measures for each alternative for a more environmentally sound project, and to avoid potential delays once the formal Department of Energy review process began. Significant constraints existed from a planning perspective, including operational issues such as existing outdoor high explosives testing areas, as well as environmental issues including threatened and endangered species habitats, multiple archeological sites, contaminated areas, and aesthetics. The study had to be completed within 45 days to meet project schedule needs. The process resulted in a number of important recommendations. While the construction and operation of the on-site power generation facility could have minimal environmental impacts, the need for a new air quality permit would create severe cost and schedule constraints for the project. From an environmental perspective, construction and operation of a power line within either corridor was concluded to be a viable alternative. However, impacts with either corridor would have to be reduced through specific recommended alignment modifications and mitigation measures

Developing guidelines for incorporating managing demand into WSDOT planning and programming: transportation demand management guidance for corridor planning studies.

Science.gov (United States)

2016-02-01

The Washington State Department of Transportation (WSDOT) regional planning programs address current and forecasted deficiencies of State highways through the conduct of corridor studies. This Guidance for the conduct of corridor planning studies is ...

Many-body correlation effects in the spatially separated electron and hole layers in the coupled quantum wells

Energy Technology Data Exchange (ETDEWEB)

Babichenko, V.S. [RRC Kurchatov Institute, Kurchatov Sq., 1, 123182 Moscow (Russian Federation); Polishchuk, I.Ya., E-mail: iyppolishchuk@gmail.com [RRC Kurchatov Institute, Kurchatov Sq., 1, 123182 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700, 9, Institutskii per., Dolgoprudny, Moscow Region (Russian Federation)

2014-11-15

The many-body correlation effects in the spatially separated electron and hole layers in the coupled quantum wells are investigated. A special case of the many-component electron–hole system is considered. It is shown that if the hole mass is much greater than the electron mass, the negative correlation energy is mainly determined by the holes. The ground state of the system is found to be the 2D electron–hole liquid with the energy smaller than the exciton phase. It is shown that the system decays into the spatially separated neutral electron–hole drops if the initially created charge density in the layers is smaller than the certain critical value n{sub eq}.

New strategies for maintaining post-seismic operations of lifeline corridors.

Science.gov (United States)

2014-10-01

This project furthered the development of three strategies that could positively impact maintaining post-seismic operations of lifeline corridors. In Year 1, most of the focus : was on the development of the three individual strategies. In Year 2, a ...

Delivery of workshops on corridor management and preservation in Texas.

Science.gov (United States)

2010-12-01

This report summarizes the delivery and outcome of a series of workshops conducted at 23 Texas : Department of Transportation (TxDOT) districts across the state on corridor management and preservation : in Texas. The workshops served as follow-up imp...

Pavement and riparian forest shape the bird community along an urban river corridor

Directory of Open Access Journals (Sweden)

Christopher J.W. McClure

2015-07-01

Full Text Available Knowledge of habitat use by animals within urban-riparian corridors during the breeding season is important for conservation, yet remains understudied. We examined the bird community along an urban-riparian corridor through metropolitan Boise, Idaho and predicted that occupancy of individual species and species richness would be greater in forested areas than in urbanized areas. We surveyed birds throughout the summers of 2009 and 2010 and quantified the m2 of each cover-type within 50-m, 100-m, and 200-m buffers surrounding each survey location using satellite imagery. Occupancy modeling revealed that eight of 14 species analyzed were positively associated with riparian forest, and no species avoided forest. Species richness was negatively associated with the amount of paved surface within 100 m of a survey site with richness declining by more than two species for every hectare of paved surface. Most associations with cover-types–especially riparian forest–were at ⩾100 m. Therefore, the riparian forest within 100 m of a given site along an urban-riparian corridor should be the most important for maintaining species richness.

Spatial variability in alluvium properties at a low-level nuclear waste site

International Nuclear Information System (INIS)

Istok, J.D.; Blout, D.O.; Barker, L.; Johnejack, K.R.; Hammermeister, D.P.

1994-01-01

Geological and statistical models for the spatial variability of soil properties are needed to predict field-scale water flow and solute transport but only limited information is currently available on unsaturated soils below the root zone. Spatial variability of selected physical and hydrologic properties was quantified for fine- and coarse-grained alluvial deposits at a low-level nuclear waste disposal site on the Nevada Test Site. Gravimetric water content (w), bulk density (ρ b ), saturated hydraulic conductivity (K a ), and particle-size distribution were determined for vertical and horizontal core specimens and bulk samples collected from 183-m-long horizontal transects in two existing waste disposal trenches located on a single alluvial fan. The transects were approximately aligned parallel and perpendicular to the principal direction of sediment transport. Properties were modeled as either normally or lognormally distributed random variables. Sample coefficients of variation were smallest for ρ b and largest for log(K a ); a weak correlation was identified between log(K a ) and the grain-size parameter d 10 . Particle-size distributions for the fine- and coarse-grained materials were different and significant differences in the natural logarithm of saturated hydraulic conductivity, log(K a ), existed between coarse and fine layers in an excavation aligned with the principal direction of alluvium deposition but not in a perpendicular direction. 37 refs., 7 figs., 11 tabs

Studi Hubungan Budaya dengan Aglomerasi Ekonomi (North-South Corridor Di Jawa Timur

Directory of Open Access Journals (Sweden)

Rachmad Kresna Sakti

2012-05-01

Full Text Available ABSTRACT   There are two things that commonly identify economic activitivities spacially such as concentration and imbalance.  East Java has two concentration poles of Java economic activities spacially. One of the concentration areas in East Java is in Surabaya, and that concentration activity is called North-South Corridor which is close to temple/ archeological site in East Java. Based on the fact, this research answers some questions like (1 Is there any interaction between culture dimension (the people and economic dimension? (2 How does culture dimension interacts with economic dimension? The aims of the research are (a To know the interaction between culture dimension (the people and economic dimension partially and cumulatively, so there will be North-South Corridor in East Java; (b To know the flow of mechanism from the detail of culture dimension interacting with economic dimension. The research was done outside North-South Corridor  area in East Java. The result of the research shows (1 there is a relationship between culture and economic dimension. It can be showed from the difference of each economic subject both inside and outside North-South Corridor in facing Hofstede Culture; (2 the difference of culture is formed by the environment of area inside and outside North-South Corridor.   Keywords: North-South Corridor, culture, economic concentration   ABSTRAKS   Terdapat dua hal yang seringkali menjadi ciri menonjol dari kegiatan perekonomian secara spasial, yaitu adanya konsentrasi dan ketimpangan. Di Pulau Jawa Terdapat dua kutub konsentrasi kegiatan ekonomi di Jawa secara spasial. Salah satunya wilayah konsentrasi kegiatan ekonomi di Surabaya Jawa Timur. Konsentrasi kegiatan tersebut dikenal dengan koridor utara – selatan. Menariknya koridor Utara-Selatan berhimpit dengan letak situs purbakala/candi di Jawa Timur.  Berpijak pada kesenjangan realita tersebut, penelitan ini berusaha menjawab pertanyaan berikut, (1 apakah

76 FR 78641 - Cedar Creek Wind Energy, LLC, Milford Wind Corridor Phase I, LLC; Notice of Filing

Science.gov (United States)

2011-12-19

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. RC11-1-002; Docket No. RC11-2-002] Cedar Creek Wind Energy, LLC, Milford Wind Corridor Phase I, LLC; Notice of Filing Take...) June 16, 2011 Order.\\1\\ \\1\\ Cedar Creek Wind Energy, LLC and Milford Wind Corridor Phase I, LLC, 135...

Dynamique institutionnelle des transferts de gestion dans le corridor ...

African Journals Online (AJOL)

Ten years after their creation, the operation of the community-based natural resource management policy named 'transfert de gestion' – the 1996 GELOSE law (applied to any kind of natural resources), and the 2001 GCF decree (only applied to forests) - remains little understood. The forest corridor linking Ranomafana and ...

The Correlation Between Schizophrenic Patients' Level of Internalized Stigma and Their Level of Hope.

Science.gov (United States)

Olçun, Zeynep; Şahin Altun, Özlem

2017-08-01

The aim of this study is to determine the correlation between schizophrenic patients' level of internalized stigma and their level of hope. The population of the study consisted of patients who had been diagnosed with schizophrenia and also met the study inclusion criteria. The study sample selection from the population was not further divided; the study was conducted with 76 patients. The data of the study were collected using a personal information form, the Internalized Stigma of Mental Illness (ISMI) Scale, and Herth Hope Scale. The patients' mean score on the Internalized Stigma Scale was 72.78±16.05. Their score on the Hope Scale is 50.36±11.91. A significant negative correlation was found between the total mean scores of ISMI and the Herth Hope Scale (r=-0.360, pHope Scale (r=0.510, phope levels were found to be moderate. A significant negative correlation was found between internalized stigma and hope. This study also found a significant positive correlation between the stigma resistance of patients and their hope levels. Copyright © 2017 Elsevier Inc. All rights reserved.

Low-Carbon Transportation Oriented Urban Spatial Structure: Theory, Model and Case Study

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Yuyao Ye

2017-12-01

Full Text Available Optimising the spatial structure of cities to promote low-carbon travel is a primary goal of urban planning and construction innovation in the low-carbon era. There is a need for basic research on the structural characteristics that help to reduce motor traffic, thereby promoting energy conservation. We first review the existing literature on the influence of urban spatial structure on transport carbon dioxide emissions and summarise the influence mechanisms. We then present two low-carbon transportation oriented patterns of urban spatial structure including the traditional walking city and the modern transit metropolis, illustrated by case studies. Furthermore, we propose an improved model Green Transportation System Oriented Development (GTOD, which is an extension of traditional transit-oriented development (TOD and includes the additional features of a walking city and an emphasis on the integration of land use with a green transportation system, consisting of the public transportation and non-auto travel system. A compact urban form, effective mix of land use and appropriate scale of block are the basic structural features of a low-carbon transportation city. However, these features are only effective at promoting low-carbon transportation when integrated with the green traffic systems. Proper integration of the urban structural system with the green space system is also required. The optimal land use/transportation integration strategy is to divide traffic corridors with wedge-shaped green spaces and limit development along the transit corridors. This strategy forms the basis of the proposed urban structural model to promote low-carbon transportation and sustainable urban growth management.

Stimulus Type, Level of Categorization, and Spatial-Frequencies Utilization: Implications for Perceptual Categorization Hierarchies

Science.gov (United States)

Harel, Assaf; Bentin, Shlomo

2009-01-01

The type of visual information needed for categorizing faces and nonface objects was investigated by manipulating spatial frequency scales available in the image during a category verification task addressing basic and subordinate levels. Spatial filtering had opposite effects on faces and airplanes that were modulated by categorization level. The…

Tree-level correlations in the strong field regime

Science.gov (United States)

Gelis, François

2017-09-01

We consider the correlation function of an arbitrary number of local observables in quantum field theory, in situations where the field amplitude is large. Using a quasi-classical approximation (valid for a highly occupied initial mixed state, or for a coherent initial state if the classical dynamics has instabilities), we show that at tree level these correlations are dominated by fluctuations at the initial time. We obtain a general expression of the correlation functions in terms of the classical solution of the field equation of motion and its derivatives with respect to its initial conditions, that can be arranged graphically as the sum of labeled trees where the nodes are the individual observables, and the links are pairs of derivatives acting on them. For 3-point (and higher) correlation functions, there are additional tree-level terms beyond the quasi-classical approximation, generated by fluctuations in the bulk.

Winter Responses of Forest Birds to Habitat Corridors and Gaps

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Colleen Cassady St. Clair

1998-12-01

Full Text Available Forest fragmentation and habitat loss may disrupt the movement or dispersal of forest-dwelling birds. Despite much interest in the severity of these effects and ways of mitigating them, little is known about actual movement patterns in different habitat types. We studied the movement of wintering resident birds, lured by playbacks of mobbing calls, to compare the willingness of forest birds to travel various distances in continuous forest, along narrow corridors (fencerows, and across gaps in forest cover. We also quantified the willingness of Black-capped Chickadees (Poecile atricapillus to cross gaps when alternative forested detour routes were available. All species were less likely to respond to the calls as distance increased to 200 m, although White-breasted Nuthatches (Sitta carolinensis and Hairy Woodpeckers (Picoides villosus were generally less likely to respond than chickadees and Downy Woodpeckers (P. pubescens. Chickadees were as likely to travel in corridors as in continuous forest, but were less likely to cross gaps as the gap distance increased. The other species were less willing to travel in corridors and gaps relative to forest, and the differences among habitats also increased with distance. For chickadees, gap-crossing decisions in the presence of forested detours varied over the range of distances that we tested, and were primarily influenced by detour efficiency (the length of the shortcut relative to the available detour. Over short distances, birds used forested detours, regardless of their efficiency. As absolute distances increased, birds tended to employ larger shortcuts in the open when detour efficiency was low or initial distance in the open was high, but they limited their distance from the nearest forest edge to 25 m. Thus, chickadees were unwilling to cross gaps of > 50 m when they had forested alternatives, yet they sometimes crossed gaps as large as 200 m when no such choice existed. Our results suggest that

Quantum correlations induced by multiple scattering of quadrature squeezed light

DEFF Research Database (Denmark)

Lodahl, Peter

2006-01-01

Propagating quadrature squeezed light through a multiple scattering random medium is found to induce pronounced spatial quantum correlations that have no classical analogue. The correlations are revealed in the number of photons transported through the sample that can be measured from the intensity...... fluctuations of the total transmission or reflection. In contrast, no pronounced spatial quantum correlations appear in the quadrature amplitudes where excess noise above the shot noise level is found....

On the role of spatial phase and phase correlation in vision, illusion, and cognition.

Science.gov (United States)

Gladilin, Evgeny; Eils, Roland

2015-01-01

Numerous findings indicate that spatial phase bears an important cognitive information. Distortion of phase affects topology of edge structures and makes images unrecognizable. In turn, appropriately phase-structured patterns give rise to various illusions of virtual image content and apparent motion. Despite a large body of phenomenological evidence not much is known yet about the role of phase information in neural mechanisms of visual perception and cognition. Here, we are concerned with analysis of the role of spatial phase in computational and biological vision, emergence of visual illusions and pattern recognition. We hypothesize that fundamental importance of phase information for invariant retrieval of structural image features and motion detection promoted development of phase-based mechanisms of neural image processing in course of evolution of biological vision. Using an extension of Fourier phase correlation technique, we show that the core functions of visual system such as motion detection and pattern recognition can be facilitated by the same basic mechanism. Our analysis suggests that emergence of visual illusions can be attributed to presence of coherently phase-shifted repetitive patterns as well as the effects of acuity compensation by saccadic eye movements. We speculate that biological vision relies on perceptual mechanisms effectively similar to phase correlation, and predict neural features of visual pattern (dis)similarity that can be used for experimental validation of our hypothesis of "cognition by phase correlation."

On the role of spatial phase and phase correlation in vision, illusion and cognition

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Evgeny eGladilin

2015-04-01

Full Text Available Numerous findings indicate that spatial phase bears an important cognitive information. Distortion of phase affects topology of edge structures and makes images unrecognizable. In turn, appropriately phase-structured patterns give rise to various illusions of virtual image content and apparent motion. Despite a large body of phenomenological evidence not much is known yet about the role of phase information in neural mechanisms of visual perception and cognition. Here, we are concerned with analysis of the role of spatial phase in computational and biological vision, emergence of visual illusions and pattern recognition. We hypothesize that fundamental importance of phase information for invariant retrieval of structural image features and motion detection promoted development of phase-based mechanisms of neural image processing in course of evolution of biological vision. Using an extension of Fourier phase correlation technique, we show that the core functions of visual system such as motion detection and pattern recognition can be facilitated by the same basic mechanism. Our analysis suggests that emergence of visual illusions can be attributed to presence of coherently phase-shifted repetitive patterns as well as the effects of acuity compensation by saccadic eye movements. We speculate that biological vision relies on perceptual mechanisms effectively similar to phase correlation, and predict neural features of visual pattern (dissimilarity that can be used for experimental validation of our hypothesis of 'cognition by phase correlation'.

Energy transport corridors: the potential role of Federal lands in states identified by the Energy Policy Act of 2005, section 368(b).

Energy Technology Data Exchange (ETDEWEB)

Krummel, J.; Hlohowskyj, I.; Kuiper, J.; Kolpa, R.; Moore, R.; May, J.; VanKuiken, J.C.; Kavicky, J.A.; McLamore, M.R.; Shamsuddin, S. (Decision and Information Sciences); ( EVS)

2011-09-01

On August 8, 2005, the President signed the Energy Policy Act of 2005 (EPAct) into law. In Subtitle F of EPAct, Congress set forth various provisions that would change the way certain federal agencies (Agencies) coordinate to authorize the use of land for a variety of energy-related purposes. As part of Subtitle F of EPAct, Section 368 addresses the issue of energy transportation corridors on federal land for oil, gas, and hydrogen pipelines, as well as electricity transmission and distribution facilities. Because of the critical importance of improving the nation's electrical transmission grid, Congress recognized that electricity transmission issues should receive added attention when the Agencies address corridor location and analysis issues. In Section 368, Congress specifically directed the Agencies to consider the need for upgraded and new facilities to deliver electricity: In carrying out [Section 368], the Secretaries shall take into account the need for upgraded and new electricity transmission and distribution facilities to (1) improve reliability; (2) relieve congestion; and (3) enhance capability of the national grid to deliver electricity. Section 368 does not require the Agencies to consider or approve specific projects, applications for rights-of-way (ROWs), or other permits within designated energy corridors. Importantly, Section 368 does not direct, license, or otherwise permit any on-the-ground activity of any sort. If an applicant is interested in obtaining an authorization to develop a project within any corridor designated under Section 368, the applicant would have to apply for a ROW authorization and applicable permits. The Agencies would consider each application by applying appropriate project-specific reviews under requirements of laws and related regulations, including, but not limited to, the National Environmental Policy Act (NEPA), the Clean Water Act, the Clean Air Act, Section 7 of the Endangered Species Act (ESA), and Section

Correlation between FSH, LH and prolactin serum levels. [Radioimmunoassay of hormones

Energy Technology Data Exchange (ETDEWEB)

Krause, W [Giessen Univ. (Germany, F.R.)

1978-01-01

In 188 males FSH, LH, and prolactin serum levels determined by radioimmunoassay from a single blood sample were found to be closely correlated. No correlation appeared to testosterone levels. The same correlation is observed, if serum levels of FSH, LH, and prolactin are measured after stimulation with LH-RH and TRH. In order to explain the close correlation, in five young men hormone levels were measured at 2-min-intervals over a period of 2 hours. Peaks of prolactin often correspond to those of FSH and LH, and a statistical correlation was found in two cases between FSH and prolactin. Results suggest a common releasing mechanism, which is superposed to the main mediating mechanism.

APPLING REMOTE SENSING TECHNIQUE TO MONITORING SPATIAL EXPANSION OF IMPORTANT CITIES IN CHINA-INDOCHINA PENINSULA ECONOMIC CORRIDOR

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J. Li

2017-09-01

Full Text Available Since twentieth Century, the process of economic globalization has made great progress, and Southeast Asia has developed rapidly under the background of international industrial transferring. In this paper, the 6 important nodes cities in China - Indochina Peninsula along the economic corridor are took as study area. The main data is time series Landsat data. The method of object-oriented random forest classification was used to extract the classification results of study area from 2000 to 2015. The urban expansion of the node cities was evaluated by calculating the expansion speed of the impervious surface and the landscape pattern metrics. The results indicated that the method of object oriented random forest classification can effectively extract the urban impervious surface. the overall accuracy is over 81 %, and the Kappa coefficient is over 0.82. In the past 15 years, the expansion speed of Vientiane city was fastest in 6 countries. The area of urban impervious surface expanded 8 times than that of 2000.The pattern of expansion is summarized as “gather first-diffuse then”, “diffuse first-gather then” and “gather”. Overall, the process of urbanization of these cities are still in the rising period.

Synaptic Correlates of Low-Level Perception in V1.

Science.gov (United States)

Gerard-Mercier, Florian; Carelli, Pedro V; Pananceau, Marc; Troncoso, Xoana G; Frégnac, Yves

2016-04-06

The computational role of primary visual cortex (V1) in low-level perception remains largely debated. A dominant view assumes the prevalence of higher cortical areas and top-down processes in binding information across the visual field. Here, we investigated the role of long-distance intracortical connections in form and motion processing by measuring, with intracellular recordings, their synaptic impact on neurons in area 17 (V1) of the anesthetized cat. By systematically mapping synaptic responses to stimuli presented in the nonspiking surround of V1 receptive fields, we provide the first quantitative characterization of the lateral functional connectivity kernel of V1 neurons. Our results revealed at the population level two structural-functional biases in the synaptic integration and dynamic association properties of V1 neurons. First, subthreshold responses to oriented stimuli flashed in isolation in the nonspiking surround exhibited a geometric organization around the preferred orientation axis mirroring the psychophysical "association field" for collinear contour perception. Second, apparent motion stimuli, for which horizontal and feedforward synaptic inputs summed in-phase, evoked dominantly facilitatory nonlinear interactions, specifically during centripetal collinear activation along the preferred orientation axis, at saccadic-like speeds. This spatiotemporal integration property, which could constitute the neural correlate of a human perceptual bias in speed detection, suggests that local (orientation) and global (motion) information is already linked within V1. We propose the existence of a "dynamic association field" in V1 neurons, whose spatial extent and anisotropy are transiently updated and reshaped as a function of changes in the retinal flow statistics imposed during natural oculomotor exploration. The computational role of primary visual cortex in low-level perception remains debated. The expression of this "pop-out" perception is often assumed

Smile attractiveness related to buccal corridor space in 3 different facial types: A perception of 3 ethnic groups of Malaysians.

Science.gov (United States)

Nimbalkar, Smita; Oh, Yih Y; Mok, Reei Y; Tioh, Jing Y; Yew, Kai J; Patil, Pravinkumar G

2018-03-16

Buccal corridor space and its variations greatly influence smile attractiveness. Facial types are different for different ethnic populations, and so is smile attractiveness. The subjective perception of smile attractiveness of different populations may vary in regard to different buccal corridor spaces and facial patterns. The purpose of this study was to determine esthetic perceptions of the Malaysian population regarding the width of buccal corridor spaces and their effect on smile esthetics in individuals with short, normal, and long faces. The image of a smiling individual with a mesofacial face was modified to create 2 different facial types (brachyfacial and dolicofacial). Each face form was further modified into 5 different buccal corridors (2%, 10%, 15%, 22%, and 28%). The images were submitted to 3 different ethnic groups of evaluators (Chinese, Malay, Indian; 100 each), ranging between 17 and 21 years of age. A visual analog scale (50 mm in length) was used for assessment. The scores given to each image were compared with the Kruskal-Wallis test, and pairwise comparison was performed using the Mann-Whitney U test (α=.05). All 3 groups of evaluators could distinguish gradations of dark spaces in the buccal corridor at 2%, 10%, and 28%. Statistically significant differences were observed among 3 groups of evaluators in esthetic perception when pairwise comparisons were performed. A 15% buccal corridor was found to score esthetically equally within 3 face types by all 3 groups of evaluators. The Indian population was more critical in evaluation than the Chinese or Malay populations. In a pairwise comparison, more significant differences were found between long and short faces and the normal face; the normal face was compared with long and short faces separately. The width of the buccal corridor space influences smile attractiveness in different facial types. A medium buccal corridor (15%) is the esthetic characteristic preferred by all groups of evaluators

Collective behavior in the spatial spreading of obesity

Science.gov (United States)

Gallos, Lazaros K.; Barttfeld, Pablo; Havlin, Shlomo; Sigman, Mariano; Makse, Hernán A.

2012-06-01

Obesity prevalence is increasing in many countries at alarming levels. A difficulty in the conception of policies to reverse these trends is the identification of the drivers behind the obesity epidemics. Here, we implement a spatial spreading analysis to investigate whether obesity shows spatial correlations, revealing the effect of collective and global factors acting above individual choices. We find a regularity in the spatial fluctuations of their prevalence revealed by a pattern of scale-free long-range correlations. The fluctuations are anomalous, deviating in a fundamental way from the weaker correlations found in the underlying population distribution indicating the presence of collective behavior, i.e., individual habits may have negligible influence in shaping the patterns of spreading. Interestingly, we find the same scale-free correlations in economic activities associated with food production. These results motivate future interventions to investigate the causality of this relation providing guidance for the implementation of preventive health policies.

Identification of priority conservation areas and potential corridors for jaguars in the Caatinga biome, Brazil.

Science.gov (United States)

Morato, Ronaldo Gonçalves; Ferraz, Katia Maria Paschoaletto Micchi de Barros; de Paula, Rogério Cunha; de Campos, Cláudia Bueno

2014-01-01

The jaguar, Panthera onca, is a top predator with the extant population found within the Brazilian Caatinga biome now known to be on the brink of extinction. Designing new conservation units and potential corridors are therefore crucial for the long-term survival of the species within the Caatinga biome. Thus, our aims were: 1) to recognize suitable areas for jaguar occurrence, 2) to delineate areas for jaguar conservation (PJCUs), 3) to design corridors among priority areas, and 4) to prioritize PJCUs. A total of 62 points records of jaguar occurrence and 10 potential predictors were analyzed in a GIS environment. A predictive distributional map was obtained using Species Distribution Modeling (SDM) as performed by the Maximum Entropy (Maxent) algorithm. Areas equal to or higher than the median suitability value of 0.595 were selected as of high suitability for jaguar occurrence and named as Priority Jaguar Conservation Units (PJCU). Ten PJCUs with sizes varying from 23.6 km2 to 4,311.0 km2 were identified. Afterwards, we combined the response curve, as generated by SDM, and expert opinions to create a permeability matrix and to identify least cost corridors and buffer zones between each PJCU pair. Connectivity corridors and buffer zone for jaguar movement included an area of 8.884,26 km2 and the total corridor length is about 160.94 km. Prioritizing criteria indicated the PJCU representing c.a. 68.61% of the total PJCU area (PJCU # 1) as of high priority for conservation and connectivity with others PJCUs (PJCUs # 4, 5 and 7) desirable for the long term survival of the species. In conclusion, by using the jaguar as a focal species and combining SDM and expert opinion we were able to create a valid framework for practical conservation actions at the Caatinga biome. The same approach could be used for the conservation of other carnivores.

Operations and maintenance plan : Dallas Integrated Corridor Management (ICM) demonstration project.

Science.gov (United States)

2014-01-01

This Operations and Maintenance (O&M) Plan describes how the Integrated Corridor Management System (ICMS) will be used in daily transportation operations and maintenance activities. The Plan addresses the activities needed to effectively operate the ...

Dispersal Ecology Informs Design of Large-Scale Wildlife Corridors.

Science.gov (United States)

Benz, Robin A; Boyce, Mark S; Thurfjell, Henrik; Paton, Dale G; Musiani, Marco; Dormann, Carsten F; Ciuti, Simone

Landscape connectivity describes how the movement of animals relates to landscape structure. The way in which movement among populations is affected by environmental conditions is important for predicting the effects of habitat fragmentation, and for defining conservation corridors. One approach has been to map resistance surfaces to characterize how environmental variables affect animal movement, and to use these surfaces to model connectivity. However, current connectivity modelling typically uses information on species location or habitat preference rather than movement, which unfortunately may not capture dispersal limitations. Here we emphasize the importance of implementing dispersal ecology into landscape connectivity, i.e., observing patterns of habitat selection by dispersers during different phases of new areas' colonization to infer habitat connectivity. Disperser animals undertake a complex sequence of movements concatenated over time and strictly dependent on species ecology. Using satellite telemetry, we investigated the movement ecology of 54 young male elk Cervus elaphus, which commonly disperse, to design a corridor network across the Northern Rocky Mountains. Winter residency period is often followed by a spring-summer movement phase, when young elk migrate with mothers' groups to summering areas, and by a further dispersal bout performed alone to a novel summer area. After another summer residency phase, dispersers usually undertake a final autumnal movement to reach novel wintering areas. We used resource selection functions to identify winter and summer habitats selected by elk during residency phases. We then extracted movements undertaken during spring to move from winter to summer areas, and during autumn to move from summer to winter areas, and modelled them using step selection functions. We built friction surfaces, merged the different movement phases, and eventually mapped least-cost corridors. We showed an application of this tool by

Correlation of Cognitive Abilities Level, Age and Ranks in Judo

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Kraček Stanislav

2016-11-01

Full Text Available The aim of this paper is to ascertain the correlation between selected cognitive abilities, age and performance of judokas according to ranking. The study group consisted of judokas in the age group 18 ± 2.4 years. The Stroop Color-Word Test - Victoria Version (VST was the instrument used to determine the level of cognitive abilities. The data obtained were measured by the Pearson Correlation (r correlation test. The results of the study show an associative relationship of indirect correlation (p < 0.01 between age and all of the three categories of the Stroop test. This is an indirect correlation, so the higher the age, the lower the time (better performance of the probands in the Stroop test. There was no statistically significant correlation between performance in the categories of the Stroop test and rankings. The outcomes show that the level of selected cognitive abilities depends on age, but the level of the selected cognitive abilities does not affect the ranking of the judokas.

Endemic and threatened tetrapods in the restingas of the biodiversity corridors of Serra do Mar and of the central da Mata Atlântica in Eastern Brazil

OpenAIRE

Rocha, C. F. D; Van Sluys, M; Bergallo, H. G.; Alves, M. A. S.

2005-01-01

Biodiversity corridors comprise a mosaic of land uses connecting fragments of natural forest across a landscape. Two such corridors have been established along the eastern coast of Brazil: the Serra do Mar and the Central da Mata Atlântica corridors, along which most of the coastal plains are restinga areas. In this study, we analyze the present status of the endemic and endangered terrestrial vertebrates of both corridors. We sampled 10 restingas in both corridors, recording species of amphi...

Socio-economic factors of bacillary dysentery based on spatial correlation analysis in Guangxi Province, China.

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Chengjing Nie

Full Text Available BACKGROUND: In the past decade, bacillary dysentery was still a big public health problem in China, especially in Guangxi Province, where thousands of severe diarrhea cases occur every year. METHODS: Reported bacillary dysentery cases in Guangxi Province were obtained from local Centers for Diseases Prevention and Control. The 14 socio-economic indexes were selected as potential explanatory variables for the study. The spatial correlation analysis was used to explore the associations between the selected factors and bacillary dysentery incidence at county level, which was based on the software of ArcGIS10.2 and GeoDA 0.9.5i. RESULTS: The proportion of primary industry, the proportion of younger than 5-year-old children in total population, the number of hospitals per thousand persons and the rates of bacillary dysentery incidence show statistically significant positive correlation. But the proportion of secondary industry, per capital GDP, per capital government revenue, rural population proportion, popularization rate of tap water in rural area, access rate to the sanitation toilets in rural, number of beds in hospitals per thousand persons, medical and technical personnel per thousand persons and the rate of bacillary dysentery incidence show statistically significant negative correlation. The socio-economic factors can be divided into four aspects, including economic development, health development, medical development and human own condition. The four aspects were not isolated from each other, but interacted with each other.

Spatial variations of storm runoff pollution and their correlation with land-use in a rapidly urbanizing catchment in China.

Science.gov (United States)

Qin, Hua-Peng; Khu, Soon-Thiam; Yu, Xiang-Ying

2010-09-15

The composition of land use for a rapidly urbanizing catchment is usually heterogeneous, and this may result in significant spatial variations of storm runoff pollution and increase the difficulties of water quality management. The Shiyan Reservoir catchment, a typical rapidly urbanizing area in China, is chosen as a study area, and temporary monitoring sites were set at the downstream of its 6 sub-catchments to synchronously measure rainfall, runoff and water quality during 4 storm events in 2007 and 2009. Due to relatively low frequency monitoring, the IHACRES and exponential pollutant wash-off simulation models are used to interpolate the measured data to compensate for data insufficiency. Three indicators, event pollutant loads per unit area (EPL), event mean concentration (EMC) and pollutant loads transported by the first 50% of runoff volume (FF50), were used to describe the runoff pollution for different pollutants in each sub-catchment during the storm events, and the correlations between runoff pollution spatial variations and land-use patterns were tested by Spearman's rank correlation analysis. The results indicated that similar spatial variation trends were found for different pollutants (EPL or EMC) in light storm events, which strongly correlate with the proportion of residential land use; however, they have different trends in heavy storm events, which correlate with not only the residential land use, but also agricultural and bare land use. And some pairs of pollutants (such as COD/BOD, NH(3)-N/TN) might have the similar source because they have strong or moderate positive spatial correlation. Moreover, the first flush intensity (FF50) varies with impervious land areas and different interception ratio of initial storm runoff volume should be adopted in different sub-catchments. Copyright 2010 Elsevier B.V. All rights reserved.

Spatial correlations in intense ionospheric scintillations - comparison between numerical computation and observation

International Nuclear Information System (INIS)

Kumagai, H.

1987-01-01

The spatial correlations in intense ionospheric scintillations were analyzed by comparing numerical results with observational ones. The observational results were obtained by spaced-receiver scintillation measurements of VHF satellite radiowave. The numerical computation was made by using the fourth-order moment equation with fairly realistic ionospheric irregularity models, in which power-law irregularities with spectral index 4, both thin and thick slabs, and both isotropic and anisotropic irregularities, were considered. Evolution of the S(4) index and the transverse correlation function was computed. The numerical result that the transverse correlation distance decreases with the increase in S(4) was consistent with that obtained in the observation, suggesting that multiple scattering plays an important role in the intense scintillations observed. The anisotropy of irregularities proved to act as if the density fluctuation increased. This effect, as well as the effect of slab thickness, was evaluated by the total phase fluctuations that the radiowave experienced in the slab. On the basis of the comparison, the irregularity height and electron-density fluctuation which is necessary to produce a particular strength of scintillation were estimated. 30 references

Evaluating the effect of sampling and spatial correlation on ground-water travel time uncertainty coupling geostatistical, stochastic, and first order, second moment methods

International Nuclear Information System (INIS)

Andrews, R.W.; LaVenue, A.M.; McNeish, J.A.

1989-01-01

Ground-water travel time predictions at potential high-level waste repositories are subject to a degree of uncertainty due to the scale of averaging incorporated in conceptual models of the ground-water flow regime as well as the lack of data on the spatial variability of the hydrogeologic parameters. The present study describes the effect of limited observations of a spatially correlated permeability field on the predicted ground-water travel time uncertainty. Varying permeability correlation lengths have been used to investigate the importance of this geostatistical property on the tails of the travel time distribution. This study uses both geostatistical and differential analysis techniques. Following the generation of a spatially correlated permeability field which is considered reality, semivariogram analyses are performed upon small random subsets of the generated field to determine the geostatistical properties of the field represented by the observations. Kriging is then employed to generate a kriged permeability field and the corresponding standard deviation of the estimated field conditioned by the limited observations. Using both the real and kriged fields, the ground-water flow regime is simulated and ground-water travel paths and travel times are determined for various starting points. These results are used to define the ground-water travel time uncertainty due to path variability. The variance of the ground-water travel time along particular paths due to the variance of the permeability field estimated using kriging is then calculated using the first order, second moment method. The uncertainties in predicted travel time due to path and parameter uncertainties are then combined into a single distribution

Green Infrastructure and Ecological Corridors: A Regional Study Concerning Sardinia

Directory of Open Access Journals (Sweden)

Ignazio Cannas

2018-04-01

Full Text Available We propose a methodological approach to identify a multifunctional green infrastructure (GI on the basis of four values (conservation value, natural value, recreation value and anthropic heritage that represent many functions (biodiversity conservation, supply of ecosystem services, recreation, identity building performed by the landscape. By taking the Italian region of Sardinia as a case study, we argue that the methodology can support the making of landscape plans as understood in the European Landscape Convention. Moreover, we propose and implement a methodology to identify ecological corridors (ECs connecting Natura 2000 sites (N2Ss, based on the prioritization of functional land patches related to their suitability to ecosystem services delivery, paying particular attention to biodiversity maintenance and enhancement, and taking Sardinia as spatial regional context. The methodology consists of two steps: (i identifying the most suitable patches to be included in ECs on the basis of their connectivity, that is, on their negative attitude towards contributing to landscape fragmentation; (ii assessing, through a discrete-choice-model, the suitability of these ECs to be included in a regional GI, starting from the territorial taxonomy based on biodiversity characteristics related to N2Ss, habitat suitability, and recreational and landscape potentials.

Transport Corridors in the Russian Integration Projects, the Case of the Eurasian Economic Union

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Olga A. Podberezkina

2015-01-01

Full Text Available The article discusses the political importance of transport corridors in terms of the development of integration projects in the post-Soviet space. The world is witnessing the formation of a single market and transport and communication infrastructure, which intensifies competition among regional and world leaders, both states and non-state actors, such as businesses, markets over the routes of transporting goods. In the medium and long term the value of the control over the transport routes will increase due to the dynamics of economic development in the Asia-Pacific region. Competition for the development of projects of international transport corridors (ITC between the leading countries in the region will increase, because the ITC entail the formation of a common political space, the reduction of tariff and customs barriers, which provides easy access to the markets of countries linked by ITCs and creates the preconditions for economic integration. The growing political importance of ITC is reflected in the fact that global leaders such as China, the US, the EU, are trying to create their own versions of international land transport corridors connecting Europe and Asia. China is trying to promote their transport project "Economic Belt Silk Road" European countries develop cooperation on ITC TRACECA with other countries of Eurasia. US also embody their interests through the implementation of the project by the ITC in Afghanistan. Transport corridors in Russia are seen as a way to integrate it into the global transportation system and logistics space. To do this, Russia needs to develop Eurasian transport corridors through its territory. As a result of the implementation of transport projects Russia will be able to ensure the transit of goods from China to Europe, which has a positive impact on the economic development of the regions through which they pass. Development of international transportation through Russia will unite many of the

Multi-Modal Traveler Information System - GCM Corridor Architecture Interface Control Requirements

Science.gov (United States)

1997-10-31

The Multi-Modal Traveler Information System (MMTIS) project involves a large number of Intelligent Transportation System (ITS) related tasks. It involves research of all ITS initiatives in the Gary-Chicago-Milwaukee (GCM) Corridor which are currently...

Research on the quality of the wine grapes in corridor area of China

Directory of Open Access Journals (Sweden)

Guo Cheng

2015-03-01

Full Text Available The corridor area of Gansu Province is one of the most important wine grape growing regions in China, and this strip of land results in a significant difference in terms of terroir between its regions. Chemical composition and antioxidant capacity of the main wine grape varieties (Vitis vinifera L. cultivated in the corridor area of Gansu Province in northwest China were compared. Three regions (Zhangye, Wuwei, and Jiayuguan were selected to explain the influence of soil and climate conditions on the quality of wine grapes. This study aims to investigate the effect of different regions on berry composition and antioxidant capacity, providing a general evaluation of red and white wine grapes quality in the corridor area of China. The results showed that ‘Merlot’ grapes grown in Zhangye had the best quality among the different varieties in the three regions of Gansu evaluated. The moderate temperature and nitrogen deficiency were associated with improved fruit quality. It was identified that the most suitable grape variety from Zhangye is ‘Merlot’, and that ‘Cabernet Sauvignon’ and ‘Italian Resling’ are the most suitable varieties from Wuwei and Jiayuguan, respectively.

A Correlational Study of Seven Projective Spatial Structures with Regard to the Phases of the MOON^

Science.gov (United States)

Wellner, Karen Linette

1995-01-01

This study investigated the relationship between projective spatial structures and the ability to construct a scientific model. In addition, gender-related performance and the influence of prior astronomy experience on task success were evaluated. Sixty-one college science undergraduates were individually administered Piagetian tasks to assess for projective spatial structures and the ability to set up a phases of the moon model. The spatial tasks included: (a) Mountains task (coordination of perspectives); (b) Railroad task (size and intervals of objects with increasing distance); (c) Telephone Poles task (masking and ordering objects); and (d) Shadows task (spatial relationships between an object and its shadow, dependent upon the object's orientation). Cramer coefficient analyses indicated that significant relationships existed between Moon task and spatial task success. In particular, the Shadows task, requiring subjects to draw shadows of objects in different orientations, proved most difficult and was most strongly associated with with a subject's understanding of lunar phases. Chi-square tests for two independent samples were used to analyze gender performance differences on each of the Ave tasks. Males performed significantly better at a.05 significance level in regard to the Shadows task and the Moon task. Chi-square tests for two independent samples showed no significant difference in Moon task performance between subjects with astronomy or Earth science coursework, and those without such science classroom experience. Overall, only six subjects passed all seven projective spatial structure tasks. Piaget (1967) contends that concrete -operational spatial structures must be established before an individual is able to develop formal-operational patterns of thinking. The results of this study indicate that 90% of the interviewed science majors are still operating at the concrete-operational level. Several educational implications were drawn from this study

Spatial correlation of conductive filaments for multiple switching cycles in CBRAM

KAUST Repository

Pey, K. L.

2014-06-01

Conducting bridge random access memory (CBRAM) is one of the potential technologies being considered for replacement of Flash memory for non-volatile data storage. CBRAM devices operate on the principle of nucleation and rupture of metallic filaments. One key concern for commercializing this technology is the question of variability which could arise due to nucleation of multiple filaments across the device at spatially different locations. The spatial spread of the filament location may cause long tails at the low and high percentile regions for the switching parameter distribution as the new filament that nucleates may have a completely different shape and size. It is therefore essential to probe whether switching in CBRAM occurs every time at the same filament location or whether there are other new filaments that could nucleate during repeated cycling with some spatial correlation (if any) to the original filament. To investigate this issue, we make use of a metal-insulator-semiconductor (M-I-S) transistor test structure with Ni as the top electrode and HfOx/SiOx as the dielectric stack. In-situ stressing using a nano-tip on the M-I-S stack is performed and the filament is imaged in real-time using a high resolution transmission electron microscope (TEM). We also extract the location of the filament (LFIL) along the channel of the transistor after the nucleation stage using the weighted proportion of the source and drain currents. © 2014 IEEE.

An assessment of the natural gas supply potential of the south energy corridor from the Caspian Region to the EU

International Nuclear Information System (INIS)

Mavrakis, Dimitrios; Thomaidis, Fotios; Ntroukas, Ioannis

2006-01-01

Security and diversification of EU energy supply underlines the importance of an energy corridor bridging the natural gas reserves of the broader Caspian Region with the EU consumption centers. This paper examines the supply potential of this corridor, the major natural gas fields and the already existing networks. An assessment of the supply cost up to the Turkish borders is carried out, while the case of Egypt as a future supplier is also investigated. Conclusions review the prospects for the construction of the considered energy corridor

Time-averaged currents in the Northeast Corridor Reserve during November 2013.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — A 2D numerical model, CMS-Flow, was implemented for the Northeast Corridor Reserve (NECR) using a telescoping grid. Tide and wind forcing was provided to the model...

Density dependence of the fine-differential disturbed gamma-gamma-spatial correlation in gaseous 111InI-sources

International Nuclear Information System (INIS)

Schuetter, K.

1985-01-01

An instrument for measuring a time-differential disturbed angular correlation was developed. Using this instrument the disturbance of the spatial correlation of the γ-quanta of the 171-245 keV γ-γ-cascade in 111 Cd was examined in dependence of the density of the gaseous 111 InI-systems and the time difference between the emission of the both γ-quanta. (BBOE)

Visual Form Perception Can Be a Cognitive Correlate of Lower Level Math Categories for Teenagers

Science.gov (United States)

Cui, Jiaxin; Zhang, Yiyun; Cheng, Dazhi; Li, Dawei; Zhou, Xinlin

2017-01-01

Numerous studies have assessed the cognitive correlates of performance in mathematics, but little research has been conducted to systematically examine the relations between visual perception as the starting point of visuospatial processing and typical mathematical performance. In the current study, we recruited 223 seventh graders to perform a visual form perception task (figure matching), numerosity comparison, digit comparison, exact computation, approximate computation, and curriculum-based mathematical achievement tests. Results showed that, after controlling for gender, age, and five general cognitive processes (choice reaction time, visual tracing, mental rotation, spatial working memory, and non-verbal matrices reasoning), visual form perception had unique contributions to numerosity comparison, digit comparison, and exact computation, but had no significant relation with approximate computation or curriculum-based mathematical achievement. These results suggest that visual form perception is an important independent cognitive correlate of lower level math categories, including the approximate number system, digit comparison, and exact computation. PMID:28824513

Fractal analytical approach of urban form based on spatial correlation function

International Nuclear Information System (INIS)

Chen, Yanguang

2013-01-01

Highlights: ► Many fractal parameter relations of cities can be derived by scaling analysis. ► The area-radius scaling of cities suggests a spatial correlation function. ► Spectral analysis can be used to estimate fractal dimension values of urban form. ► The valid range of fractal dimension of urban form comes between 1.5 and 2. ► The traditional scale concept will be replaced by scaling concept in geography. -- Abstract: Urban form has been empirically demonstrated to be of scaling invariance and can be described with fractal geometry. However, the rational range of fractal dimension value and the relationships between various fractal indicators of cities are not yet revealed in theory. By mathematical deduction and transform (e.g., Fourier transform), I find that scaling analysis, spectral analysis, and spatial correlation analysis are all associated with fractal concepts and can be integrated into a new approach to fractal analysis of cities. This method can be termed ‘3S analyses’ of urban form. Using the 3S analysis, I derived a set of fractal parameter equations, by which different fractal parameters of cities can be linked up with one another. Each fractal parameter has its own reasonable extent of values. According to the fractal parameter equations, the intersection of the rational ranges of different fractal parameters suggests the proper scale of the fractal dimension of urban patterns, which varies from 1.5 to 2. The fractal dimension equations based on the 3S analysis and the numerical relationships between different fractal parameters are useful for geographers to understand urban evolution and potentially helpful for future city planning

Reducing the impact of speed dispersion on subway corridor flow.

Science.gov (United States)

Qiao, Jing; Sun, Lishan; Liu, Xiaoming; Rong, Jian

2017-11-01

The rapid increase in the volume of subway passengers in Beijing has necessitated higher requirements for the safety and efficiency of subway corridors. Speed dispersion is an important factor that affects safety and efficiency. This paper aims to analyze the management control methods for reducing pedestrian speed dispersion in subways. The characteristics of the speed dispersion of pedestrian flow were analyzed according to field videos. The control measurements which were conducted by placing traffic signs, yellow marking, and guardrail were proposed to alleviate speed dispersion. The results showed that the methods of placing traffic signs, yellow marking, and a guardrail improved safety and efficiency for all four volumes of pedestrian traffic flow, and the best-performing control measurement was guardrails. Furthermore, guardrails' optimal position and design measurements were explored. The research findings provide a rationale for subway managers in optimizing pedestrian traffic flow in subway corridors. Copyright © 2017. Published by Elsevier Ltd.

Spatial and temporal variability of drought in the arid region of China and its relationships to teleconnection indices

Science.gov (United States)

Wang, Huaijun; Chen, Yaning; Pan, Yingping; Li, Weihong

2015-04-01

We studied the drought patterns in the arid region of northwestern China between 1960 and 2010 using the Palmer Drought Severity Index (PDSI). The general evolution of drought was obtained by empirical orthogonal function (EOF), rotated empirical orthogonal function (REOF), the Mann-Kendall test, and the continuous wavelet transform method. Additionally, relationships between rotated principal component time series (RPCs) and seven selected climate indices were analyzed. The results showed that: (1) Four moisture-related spatial patterns (North Xinjiang, western South Xinjiang, Central Xinjiang, and the Hexi Corridor) were objectively defined by REOF analysis. These patterns are related to distinct geographical areas and are associated with distinct temporal variations. (2) The PDSI increased significantly in most regions of Xinjiang, while decreased in the eastern Hexi Corridor. The significant 4-8 year band is the major period band for the annual and seasonal PDSI derived. (3) The seasonal REOFs (RPCs) and EOFs (PCs) have consistent spatial distribution patterns with the annual REOF. The seasonal trends of PDSI are also the same as the annual PDSI trends, indicating space-time consistency between annual PDSI and seasonal PDSI. (4) The drought evolution in this region is affected by the area of northern hemisphere polar vortex, the Arctic Oscillation, and the North Atlantic Oscillation. In addition, the changes of drought in South Xinjiang and the Hexi Corridor may also be associated with the Tibetan Plateau High. Changes in drought pattern are expected to have a strong impact on the economic livelihood of the region, especially for agricultural production.

Enhancing spatial detection accuracy for syndromic surveillance with street level incidence data

Directory of Open Access Journals (Sweden)

Alemi Farrokh

2010-01-01

Full Text Available Abstract Background The Department of Defense Military Health System operates a syndromic surveillance system that monitors medical records at more than 450 non-combat Military Treatment Facilities (MTF worldwide. The Electronic Surveillance System for Early Notification of Community-based Epidemics (ESSENCE uses both temporal and spatial algorithms to detect disease outbreaks. This study focuses on spatial detection and attempts to improve the effectiveness of the ESSENCE implementation of the spatial scan statistic by increasing the spatial resolution of incidence data from zip codes to street address level. Methods Influenza-Like Illness (ILI was used as a test syndrome to develop methods to improve the spatial accuracy of detected alerts. Simulated incident clusters of various sizes were superimposed on real ILI incidents from the 2008/2009 influenza season. Clusters were detected using the spatial scan statistic and their displacement from simulated loci was measured. Detected cluster size distributions were also evaluated for compliance with simulated cluster sizes. Results Relative to the ESSENCE zip code based method, clusters detected using street level incidents were displaced on average 65% less for 2 and 5 mile radius clusters and 31% less for 10 mile radius clusters. Detected cluster size distributions for the street address method were quasi normal and sizes tended to slightly exceed simulated radii. ESSENCE methods yielded fragmented distributions and had high rates of zero radius and oversized clusters. Conclusions Spatial detection accuracy improved notably with regard to both location and size when incidents were geocoded to street addresses rather than zip code centroids. Since street address geocoding success rates were only 73.5%, zip codes were still used for more than one quarter of ILI cases. Thus, further advances in spatial detection accuracy are dependant on systematic improvements in the collection of individual

Introduction to the transverse spatial correlations in spontaneous parametric down-conversion through the biphoton birth zone

International Nuclear Information System (INIS)

Schneeloch, James; Howell, John C

2016-01-01

As a tutorial to the spatial aspects of spontaneous parametric downconversion (SPDC), we present a detailed first-principles derivation of the transverse correlation width of photon pairs in degenerate collinear SPDC. This width defines the size of a biphoton birth zone, the region where the signal and idler photons are likely to be found when conditioning on the position of the destroyed pump photon. Along the way, we discuss the quantum-optical calculation of the amplitude for the SPDC process, as well as its simplified form for nearly collinear degenerate phase matching. Following this, we show how this biphoton amplitude can be approximated with a double-Gaussian wavefunction, and give a brief discussion of the measurement statistics (and subsequent convenience) of such double-Gaussian wavefunctions. Next, we use this approximation to get a simplified estimation of the transverse correlation width, and compare it to more accurate calculations as well as experimental results. We then conclude with a discussion of the concept of a biphoton birth zone, using it to develop intuition for the tradeoff between the first-order spatial coherence and bipohoton correlations in SPDC. (tutorial)

Spatial correlation in 3D MIMO channels using fourier coefficients of power spectrums

KAUST Repository

Nadeem, Qurrat-Ul-Ain

2015-03-01

In this paper, an exact closed-form expression for the Spatial Correlation Function (SCF) is derived for the standardized three-dimensional (3D) multiple-input multiple-output (MIMO) channel. This novel SCF is developed for a uniform linear array of antennas with non-isotropic antenna patterns. The proposed method resorts to the spherical harmonic expansion (SHE) of plane waves and the trigonometric expansion of Legendre and associated Legendre polynomials to obtain a closed-form expression for the SCF for arbitrary angular distributions and antenna patterns. The resulting expression depends on the underlying angular distributions and antenna patterns through the Fourier Series (FS) coefficients of power azimuth and elevation spectrums. The novelty of the proposed method lies in the SCF being valid for any 3D propagation environment. Numerical results validate the proposed analytical expression and study the impact of angular spreads on the correlation. The derived SCF will help evaluate the performance of correlated 3D MIMO channels in the future. © 2015 IEEE.

Correlated Raman micro-spectroscopy and scanning electron microscopy analyses of flame retardants in environmental samples: a micro-analytical tool for probing chemical composition, origin and spatial distribution.

Science.gov (United States)

Ghosal, Sutapa; Wagner, Jeff

2013-07-07

We present correlated application of two micro-analytical techniques: scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and Raman micro-spectroscopy (RMS) for the non-invasive characterization and molecular identification of flame retardants (FRs) in environmental dusts and consumer products. The SEM/EDS-RMS technique offers correlated, morphological, molecular, spatial distribution and semi-quantitative elemental concentration information at the individual particle level with micrometer spatial resolution and minimal sample preparation. The presented methodology uses SEM/EDS analyses for rapid detection of particles containing FR specific elements as potential indicators of FR presence in a sample followed by correlated RMS analyses of the same particles for characterization of the FR sub-regions and surrounding matrices. The spatially resolved characterization enabled by this approach provides insights into the distributional heterogeneity as well as potential transfer and exposure mechanisms for FRs in the environment that is typically not available through traditional FR analysis. We have used this methodology to reveal a heterogeneous distribution of highly concentrated deca-BDE particles in environmental dust, sometimes in association with identifiable consumer materials. The observed coexistence of deca-BDE with consumer material in dust is strongly indicative of its release into the environment via weathering/abrasion of consumer products. Ingestion of such enriched FR particles in dust represents a potential for instantaneous exposure to high FR concentrations. Therefore, correlated SEM/RMS analysis offers a novel investigative tool for addressing an area of important environmental concern.

Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor.

Science.gov (United States)

Kessel, Steven T; Hondorp, Darryl W; Holbrook, Christopher M; Boase, James C; Chiotti, Justin A; Thomas, Michael V; Wills, Todd C; Roseman, Edward F; Drouin, Richard; Krueger, Charles C

2018-01-01

Population structure, distribution, abundance and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations are an important aspect of the ecology of highly mobile animals, allowing populations to exploit spatially or temporally distributed food and space resources. This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes. Over 6 years (2011-2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 years battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use. Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assigned to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 "contingents" (spatiotemporally segregated subgroups). Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

Divergent migration within lake sturgeon (Acipenser fulvescens) populations: Multiple distinct patterns exist across an unrestricted migration corridor

Science.gov (United States)

Kessel, Steven T.; Hondorp, Darryl W.; Holbrook, Christopher; Boase, James C.; Chiotti, Justin A.; Thomas, Michael V.; Wills, Todd C.; Roseman, Edward; Drouin, Richard; Krueger, Charles C.

2018-01-01

Population structure, distribution, abundance, and dispersal arguably underpin the entire field of animal ecology, with consequences for regional species persistence, and provision of ecosystem services. Divergent migration behaviours among individuals or among populations is an important aspect of the ecology of highly-mobile animals, allowing populations to exploit spatially- or temporally-distributed food and space resources.This study investigated the spatial ecology of lake sturgeon (Acipenser fulvescens) within the barrier free Huron-Erie Corridor (HEC), which connects Lake Huron and Lake Erie of the North American Laurentian Great Lakes.Over six years (2011 – 2016), movements of 268 lake sturgeon in the HEC were continuously monitored across the Great Lakes using acoustic telemetry (10 yr battery life acoustic transmitters). Five distinct migration behaviours were identified with hierarchical cluster analysis, based on the phenology and duration of river and lake use.Lake sturgeon in the HEC were found to contain a high level of intraspecific divergent migration, including partial migration with the existence of residents. Specific behaviours included year-round river residency and multiple lake-migrant behaviours that involved movements between lakes and rivers. Over 85% of individuals were assign to migration behaviours as movements were consistently repeated over the study, which suggested migration behaviours were consistent and persistent in lake sturgeon. Differential use of specific rivers or lakes by acoustic-tagged lake sturgeon further subdivided individuals into 14 “contingents” (spatiotemporally segregated subgroups).Contingents associated with one river (Detroit or St. Clair) were rarely detected in the other river, which confirmed that lake sturgeon in the Detroit and St. Clair represent two semi-independent populations that could require separate management consideration for their conservation. The distribution of migration behaviours

A cell-based study on pedestrian acceleration and overtaking in a transfer station corridor

Science.gov (United States)

Ji, Xiangfeng; Zhou, Xuemei; Ran, Bin

2013-04-01

Pedestrian speed in a transfer station corridor is faster than usual and sometimes running can be found among some of them. In this paper, pedestrians are divided into two categories. The first one is aggressive, and the other is conservative. Aggressive pedestrians weaving their way through crowd in the corridor are the study object of this paper. During recent decades, much attention has been paid to the pedestrians' behavior, such as overtaking (also deceleration) and collision avoidance, and that continues in this paper. After sufficiently analyzing the characteristics of pedestrian flow in transfer station corridor, a cell-based model is presented in this paper, including the acceleration (also deceleration) and overtaking analysis. Acceleration (also deceleration) in a corridor is fixed according to Newton's Law and then speed calculated with a kinematic formula is discretized into cells based on the fuzzy logic. After the speed is updated, overtaking is analyzed based on updated speed and force explicitly, compared to rule-based models, which herein we call implicit ones. During the analysis of overtaking, a threshold value to determine the overtaking direction is introduced. Actually, model in this paper is a two-step one. The first step is to update speed, which is the cells the pedestrian can move in one time interval and the other is to analyze the overtaking. Finally, a comparison between the rule-based cellular automata, the model in this paper and data in HCM 2000 is made to demonstrate our model can be used to achieve reasonable simulation of acceleration (also deceleration) and overtaking among pedestrians.

Biomass and nutrient allocation strategies in a desert ecosystem in the Hexi Corridor, northwest China.

Science.gov (United States)

Zhang, Ke; Su, YongZhong; Yang, Rong

2017-07-01

The allocation of biomass and nutrients in plants is a crucial factor in understanding the process of plant structures and dynamics to different environmental conditions. In this study, we present a comprehensive scaling analysis of data from a desert ecosystem to determine biomass and nutrient (carbon (C), nitrogen (N), and phosphorus (P)) allocation strategies of desert plants from 40 sites in the Hexi Corridor. We found that the biomass and levels of C, N, and P storage were higher in shoots than in roots. Roots biomass and nutrient storage were concentrated at a soil depth of 0-30 cm. Scaling relationships of biomass, C storage, and P storage between shoots and roots were isometric, but that of N storage was allometric. Results of a redundancy analysis (RDA) showed that soil nutrient densities were the primary factors influencing biomass and nutrient allocation, accounting for 94.5% of the explained proportion. However, mean annual precipitation was the primary factor influencing the roots biomass/shoots biomass (R/S) ratio. Furthermore, Pearson's correlations and regression analyses demonstrated that although the biomass and nutrients that associated with functional traits primarily depended on soil conditions, mean annual precipitation and mean annual temperature had greater effects on roots biomass and nutrient storage.

A synthesis of hydrochemistry with an integrated conceptual model for groundwater in the Hexi Corridor, northwestern China

Science.gov (United States)

Wang, Liheng; Dong, Yanhui; Xu, Zhifang

2017-09-01

Although many studies have investigated the recharge and evolution of groundwater in the Hexi Corridor, northwestern (NW) China, they describe individual sites such as Jinchang, Jiuquan, Dunhuang, and others. Considering the similarity of these sites, a systematic review of the entire Hexi Corridor is lacking. This paper compares and summarizes previous studies in the Hexi Corridor to provide a regional perspective of the isotopic characteristics and hydrochemical composition of groundwater. In unconfined aquifers, groundwater is recharged by snow and ice melt water from the Qilian Mountains; local precipitation can be neglected. Therefore, the groundwater belongs to a unique hydrological cycle model in the Hexi Corridor, referred to as snow and ice melt water-groundwater system. The dominant anion species changes from HCO3- in front of the mountains to SO42- in the middle basin and Cl- at the basin boundary along the groundwater flow direction, and TDS increases gradually owing to evaporation. A major hydrogeochemical process is the dissolution of minerals from the aquifer in the recharge area changing to cation exchange reactions in the discharge area. Confined groundwater was recharged mainly in the late Pleistocene and middle Holocene at colder temperatures than those of modern times; thus, it is non-renewable. In addition to dissolution, the hydrochemical composition of confined groundwater is also affected by cation exchange reactions. The hydrogeochemical categories of the confined groundwater are simple and stable. In the present study, a conceptual model is established on the basis of the analyses presented, which has important implications for water resource management in the Hexi Corridor. The inter-basin water allocation program should continue in order to achieve optimal utilization of water resources, but groundwater exploitation should be limited as much as possible. Additionally, on the basis of the review and integration of previous research, the

Geodynamical Evolution of the En echelon Basins in the Hexi Corridor: Implications From 3-D Numerical Modeling

Science.gov (United States)

Li, W.; Shi, Y.; Zhang, H.; Cheng, H.

2017-12-01

The Hexi Corridor, located between the Alax block and the Caledon fold belt in the North Qilian Mountains, is the forefront area of northward thrust of the Tibet Plateau. Most notably, this active tectonic region consists of a series of faults and western-northwest trending Cenozoic basins. Therefore, it's a pivotal part in terms of recording tectonic pattern of the Tibet Plateau and also demonstrating the northward growth of Tibetan Plateau. In order to explain the mechanism of formation and evolution of the paired basins in the Hexi Corridor and based on the visco-elasticity-plasticity constitutive relation, we construct a 3-D finite element numerical model, including the Altun Tagh fault zone, the northern Qilian Shan-Hexi corridor faults system and the Haiyuan fault zone in northeast of the Tibet Plateau.The boundary conditions are constrained by GPS observations and fault slip rate provided by field geology, with steady rate of deformation of north-south compression and lateral shear along the approximately east-west strike fault zones.In our numerical model, different blocks are given different mechanical features and major fault zones are assumed mechanical weak zones. The long-term (5Ma) accumulation of lithospheric stress, displacement and fault dislocation of the Hexi Corridor and its adjacent regions are calculated in different models for comparison. Meanwhile, we analyze analyzed how the crustal heterogeneity affecting the tectonic deformations in this region. Comparisons between the numerical results and the geological observations indicate that under compression-shear boundary conditions, heterogeneous blocks of various scales may lead to the development of en echelon faults and basins in the Hexi corridor. And the ectonic deformation of Alax and the North Qilian Mountains are almost simultaneous, which may be earlier than the initiation of en echelon basins in the Hexi Corridor and the faults between the en echelon basins. Calculated horizontal and

Cooperative Business Structures for Green Transport Corridors

Directory of Open Access Journals (Sweden)

Prause Gunnar

2017-10-01

Full Text Available In its White Paper on “A Sustainable Future of Transport”, the European Commission promoted the idea of green transport corridors (GTCs by establishing trans-shipment routes with concentration of freight traffic between major hubs. GTCs reduce environmental and climate impact of the traffic on these relatively long distances of transport while increasing safety and efficiency with the application of sustainable logistics solutions. The Baltic Sea Region (BSR enjoys a vanguard position in the development and realisation of green transport concepts within Europe.

Garden State Parkway Corridor : ITS early deployment planning study : strategic deployment plan

Science.gov (United States)

1997-12-01

This Strategic Deployment Plan describes ways of improving travel within the Garden : State Parkway Corridor using intelligent transportation systems (ITS) and without : constructing additional roadway lanes. Travel improvements will be possible with...

Spatial and temporal correlation between beach and wave processes: implications for bar-berm sediment transition

Science.gov (United States)

Joevivek, V.; Chandrasekar, N.; Saravanan, S.; Anandakumar, H.; Thanushkodi, K.; Suguna, N.; Jaya, J.

2018-06-01

Investigation of a beach and its wave conditions is highly requisite for understanding the physical processes in a coast. This study composes spatial and temporal correlation between beach and nearshore processes along the extensive sandy beach of Nagapattinam coast, southeast peninsular India. The data collection includes beach profile, wave data, and intertidal sediment samples for 2 years from January 2011 to January 2013. The field data revealed significant variability in beach and wave morphology during the northeast (NE) and southwest (SW) monsoon. However, the beach has been stabilized by the reworking of sediment distribution during the calm period. The changes in grain sorting and longshore sediment transport serve as a clear evidence of the sediment migration that persevered between foreshore and nearshore regions. The Empirical Orthogonal Function (EOF) analysis and Canonical Correlation Analysis (CCA) were utilized to investigate the spatial and temporal linkages between beach and nearshore criterions. The outcome of the multivariate analysis unveiled that the seasonal variations in the wave climate tends to influence the bar-berm sediment transition that is discerned in the coast.

Spatial and temporal correlation between beach and wave processes: implications for bar-berm sediment transition

Science.gov (United States)

Joevivek, V.; Chandrasekar, N.; Saravanan, S.; Anandakumar, H.; Thanushkodi, K.; Suguna, N.; Jaya, J.

2017-06-01

Investigation of a beach and its wave conditions is highly requisite for understanding the physical processes in a coast. This study composes spatial and temporal correlation between beach and nearshore processes along the extensive sandy beach of Nagapattinam coast, southeast peninsular India. The data collection includes beach profile, wave data, and intertidal sediment samples for 2 years from January 2011 to January 2013. The field data revealed significant variability in beach and wave morphology during the northeast (NE) and southwest (SW) monsoon. However, the beach has been stabilized by the reworking of sediment distribution during the calm period. The changes in grain sorting and longshore sediment transport serve as a clear evidence of the sediment migration that persevered between foreshore and nearshore regions. The Empirical Orthogonal Function (EOF) analysis and Canonical Correlation Analysis (CCA) were utilized to investigate the spatial and temporal linkages between beach and nearshore criterions. The outcome of the multivariate analysis unveiled that the seasonal variations in the wave climate tends to influence the bar-berm sediment transition that is discerned in the coast.

The Information Content of Corridor Volatility Measures During Calm and Turmoil Periods

Directory of Open Access Journals (Sweden)

Elyas Elyasiani

2017-12-01

Full Text Available Measurement of volatility is of paramount importance in finance because of the effects on risk measurement and risk management. Corridor implied volatility measures allow us to disentangle the volatility of positive returns from that of negative returns, providing investors with additional information beyond standard market volatility. The aim of the paper is twofold. First, to propose different types of corridor implied volatility and some combinations of them as risk indicators, in order to provide useful information about investors’ sentiment and future market returns. Second, to investigate their usefulness in prediction of market returns under different market conditions (with a particular focus on the subprime crisis and the European debt crisis. The data set consists of daily index options traded on the Italian market and covers the 2005–2014 period. We find that upside corridor implied volatility measure embeds the highest information content about contemporaneous market returns, claiming the superiority of call options in measuring current sentiment in the market. Moreover, both upside and downside volatilities can be considered as barometers of investors’ fear. The volatility measures proposed have forecasting power on future returns only during high volatility periods and in particular during the European debt crisis. The explanatory power on future market returns improves when two of the proposed volatility measures are combined together in the same model.

Mapping end-stage renal disease (ESRD: spatial variations on small area level in northern France, and association with deprivation.

Directory of Open Access Journals (Sweden)

Florent Occelli

Full Text Available Strong geographic variations in the incidence of end-stage renal disease (ESRD are observed in developed countries. The reasons for these variations are unknown. They may reflect regional inequalities in the population's sociodemographic characteristics, related diseases, or medical practice patterns. In France, at the district level, the highest incidence rates have been found in the Nord-Pas-de-Calais region. This area, with a high population density and homogeneous healthcare provision, represents a geographic situation which is quite suitable for the study, over small areas, of spatial disparities in the incidence of ESRD, together with their correlation with a deprivation index and other risk factors.The Renal Epidemiology and Information Network is a national registry, which lists all ESRD patients in France. All cases included in the Nord-Pas-de-Calais registry between 2005 and 2011 were extracted. Adjusted and smoothed standardized incidence ratio (SIR was calculated for each of the 170 cantons, thanks to a hierarchical Bayesian model. The correlation between ESRD incidence and deprivation was assessed using the quintiles of Townsend index. Relative risk (RR and credible intervals (CI were estimated for each quintile.Significant spatial disparities in ESRD incidence were found within the Nord-Pas-de-Calais region. The sex- and age-adjusted, smoothed SIRs varied from 0.66 to 1.64. Although no correlation is found with diabetic or vascular nephropathy, the smoothed SIRs are correlated with the Townsend index (RR: 1.18, 95% CI [1.00-1.34] for Q2; 1.28, 95% CI [1.11-1.47] for Q3; 1.30, 95% CI [1.14-1.51] for Q4; 1.44, 95% CI [1.32-1.74] for Q5.For the first time at this aggregation level in France, this study reveals significant geographic differences in ESRD incidence. Unlike the time of renal replacement care, deprivation is certainly a determinant in this phenomenon. This association is probably independent of the patients' financial

Multiview Bayesian Correlated Component Analysis

DEFF Research Database (Denmark)

Kamronn, Simon Due; Poulsen, Andreas Trier; Hansen, Lars Kai

2015-01-01

are identical. Here we propose a hierarchical probabilistic model that can infer the level of universality in such multiview data, from completely unrelated representations, corresponding to canonical correlation analysis, to identical representations as in correlated component analysis. This new model, which...... we denote Bayesian correlated component analysis, evaluates favorably against three relevant algorithms in simulated data. A well-established benchmark EEG data set is used to further validate the new model and infer the variability of spatial representations across multiple subjects....

Learning to echolocate in sighted people: a correlational study on attention, working memory and spatial abilities.

Science.gov (United States)

Ekkel, M R; van Lier, R; Steenbergen, B

2017-03-01

Echolocation can be beneficial for the orientation and mobility of visually impaired people. Research has shown considerable individual differences for acquiring this skill. However, individual characteristics that affect the learning of echolocation are largely unknown. In the present study, we examined individual factors that are likely to affect learning to echolocate: sustained and divided attention, working memory, and spatial abilities. To that aim, sighted participants with normal hearing performed an echolocation task that was adapted from a previously reported size-discrimination task. In line with existing studies, we found large individual differences in echolocation ability. We also found indications that participants were able to improve their echolocation ability. Furthermore, we found a significant positive correlation between improvement in echolocation and sustained and divided attention, as measured in the PASAT. No significant correlations were found with our tests regarding working memory and spatial abilities. These findings may have implications for the development of guidelines for training echolocation that are tailored to the individual with a visual impairment.

Planar spatial correlations, anisotropy, and specific surface area of stationary random porous media

International Nuclear Information System (INIS)

Berryman, J.G.

1998-01-01

An earlier result of the author showed that an anisotropic spatial correlation function of a random porous medium could be used to compute the specific surface area when it is stationary as well as anisotropic by first performing a three-dimensional radial average and then taking the first derivative with respect to lag at the origin. This result generalized the earlier result for isotropic porous media of Debye et al. [J. Appl. Phys. 28, 679 (1957)]. The present article provides more detailed information about the use of spatial correlation functions for anisotropic porous media and in particular shows that, for stationary anisotropic media, the specific surface area can be related to the derivative of the two-dimensional radial average of the correlation function measured from cross sections taken through the anisotropic medium. The main concept is first illustrated using a simple pedagogical example for an anisotropic distribution of spherical voids. Then, a general derivation of formulas relating the derivative of the planar correlation functions to surface integrals is presented. When the surface normal is uniformly distributed (as is the case for any distribution of spherical voids), our formulas can be used to relate a specific surface area to easily measurable quantities from any single cross section. When the surface normal is not distributed uniformly (as would be the case for an oriented distribution of ellipsoidal voids), our results show how to obtain valid estimates of specific surface area by averaging measurements on three orthogonal cross sections. One important general observation for porous media is that the surface area from nearly flat cracks may be underestimated from measurements on orthogonal cross sections if any of the cross sections happen to lie in the plane of the cracks. This result is illustrated by taking the very small aspect ratio (penny-shaped crack) limit of an oblate spheroid, but holds for other types of flat surfaces as well

Recent Positioning Techniques for Efficient Port Operations and Development of Suez Canal Corridor

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Ahmed Elhattab

2016-12-01

Full Text Available The current developments in positioning techniques and communication technology have great impact on both construction and operations of ports. The majority of positioning systems for marine traffic are satellite based such as GPS. Virtual Reference Station is one of the recent high precision techniques for GNSS positioning which can be used for smart and efficient port.The advantages of using virtual reference station technique in different port operation and construction have been discussed in this paper. To apply this technique in Suez Canal corridor zone, a design of Continuously Operating Reference Station network has been proposed. This network can be utilized during different construction and operations phases of Suez Canal Corridor project.  

Triple collocation-based estimation of spatially correlated observation error covariance in remote sensing soil moisture data assimilation

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Wu, Kai; Shu, Hong; Nie, Lei; Jiao, Zhenhang

2018-01-01

Spatially correlated errors are typically ignored in data assimilation, thus degenerating the observation error covariance R to a diagonal matrix. We argue that a nondiagonal R carries more observation information making assimilation results more accurate. A method, denoted TC_Cov, was proposed for soil moisture data assimilation to estimate spatially correlated observation error covariance based on triple collocation (TC). Assimilation experiments were carried out to test the performance of TC_Cov. AMSR-E soil moisture was assimilated with a diagonal R matrix computed using the TC and assimilated using a nondiagonal R matrix, as estimated by proposed TC_Cov. The ensemble Kalman filter was considered as the assimilation method. Our assimilation results were validated against climate change initiative data and ground-based soil moisture measurements using the Pearson correlation coefficient and unbiased root mean square difference metrics. These experiments confirmed that deterioration of diagonal R assimilation results occurred when model simulation is more accurate than observation data. Furthermore, nondiagonal R achieved higher correlation coefficient and lower ubRMSD values over diagonal R in experiments and demonstrated the effectiveness of TC_Cov to estimate richly structuralized R in data assimilation. In sum, compared with diagonal R, nondiagonal R may relieve the detrimental effects of assimilation when simulated model results outperform observation data.

Thermal Comfort at the Street Corridor Around Public Places, Case Study Alun-Alun Malang City

OpenAIRE

Winansih, Erna; Antariksa, Antariksa; Surjono, Surjono; Leksono, Amin Setyo

2015-01-01

Malang as the second largest city in East Java province become crowded recently. The congestion almost happens everyday. The scenery of the street corridor is full of iron stacks. It is said that Malang city is less comfortable and less walkable. The decrease of this environment encourages to conduct the study (Q.S. 16:90, Q.S. 96:1-5, Q.S. 30:41). The study aimed to analyze the thermal comfort at pedestrian ways around Malang city squares, the street corridor of Merdeka Alun-Alun (MAA) and t...

The Suitability of Different Nighttime Light Data for GDP Estimation at Different Spatial Scales and Regional Levels

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Zhaoxin Dai

2017-02-01

Full Text Available Nighttime light data offer a unique view of the Earth’s surface and can be used to estimate the spatial distribution of gross domestic product (GDP. Historically, using a simple regression function, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP/OLS has been used to correlate regional and global GDP values. In early 2013, the first global Suomi National Polar-orbiting Partnership (NPP visible infrared imaging radiometer suite (VIIRS nighttime light data were released. Compared with DMSP/OLS, they have a higher spatial resolution and a wider radiometric detection range. This paper aims to study the suitability of the two nighttime light data sources for estimating the GDP relationship between the provincial and city levels in Mainland China, as well as of different regression functions. First, NPP/VIIRS nighttime light data for 2014 are corrected with DMSP/OLS data for 2013 to reduce the background noise in the original data. Subsequently, three regression functions are used to estimate the relationship between nighttime light data and GDP statistical data at the provincial and city levels in Mainland China. Then, through the comparison of the relative residual error (RE and the relative root mean square error (RRMSE parameters, a systematical assessment of the suitability of the GDP estimation is provided. The results show that the NPP/VIIRS nighttime light data are better than the DMSP/OLS data for GDP estimation, whether at the provincial or city level, and that the power function and polynomial models are better for GDP estimation than the linear regression model. This study reveals that the accuracy of GDP estimation based on nighttime light data is affected by the resolution of the data and the spatial scale of the study area, as well as by the land cover types and industrial structures of the study area.

Hydrologic indicators of hot spots and hot moments of mercury methylation potential along river corridors

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Singer, Michael B.; Harrison, Lee R.; Donovan, Patrick M.; Blum, Joel D.; Marvin-DiPasquale, Mark C.

2016-01-01

The biogeochemical cycling of metals and other contaminants in river-floodplain corridors is controlled by microbial activity responding to dynamic redox conditions. Riverine flooding thus has the potential to affect speciation of redox-sensitive metals such as mercury (Hg). Therefore, inundation history over a period of decades potentially holds information on past production of bioavailable Hg. We investigate this within a Northern California river system with a legacy of landscape-scale 19th century hydraulic gold mining. We combine hydraulic modeling, Hg measurements in sediment and biota, and first-order calculations of mercury transformation to assess the potential role of river floodplains in producing monomethylmercury (MMHg), a neurotoxin which accumulates in local and migratory food webs. We identify frequently inundated floodplain areas, as well as floodplain areas inundated for long periods. We quantify the probability of MMHg production potential (MPP) associated with hydrology in each sector of the river system as a function of the spatial patterns of overbank inundation and drainage, which affect long-term redox history of contaminated sediments. Our findings identify river floodplains as periodic, temporary, yet potentially important, loci of biogeochemical transformation in which contaminants may undergo change during limited periods of the hydrologic record. We suggest that inundation is an important driver of MPP in river corridors and that the entire flow history must be analyzed retrospectively in terms of inundation magnitude and frequency in order to accurately assess biogeochemical risks, rather than merely highlighting the largest floods or low-flow periods. MMHg bioaccumulation within the aquatic food web in this system may pose a major risk to humans and waterfowl that eat migratory salmonids, which are being encouraged to come up these rivers to spawn. There is a long-term pattern of MPP under the current flow regime that is likely to be

Effects of fading and spatial correlation on node selection for estimation in Wireless Sensor Networks

KAUST Repository

Al-Murad, Tamim M.

2010-06-01

In densely deployed sensor networks, correlation among measurements may be high. Spatial sampling through node selection is usually used to minimize this correlation and to save energy consumption. However because of the fading nature of the wireless channels, extra care should be taken when performing this sampling. In this paper, we develop expressions for the distortion which include the channel effects. The asymptotic behavior of the distortion as the number of sensors or total transmit power increase without bound is also investigated. Further, based on the channel and position information we propose and test several node selection schemes.

Bidirectional recovery patterns of Mojave Desert vegetation in an aqueduct pipeline corridor after 36 years: I. Perennial shrubs and grasses

Science.gov (United States)

Berry, Kristin H.; Weigand, James F.; Gowan, Timothy A.; Mack, Jeremy S.

2015-01-01

We studied recovery of 21 perennial plant species along a severely disturbed aqueduct corridor in a Larrea tridentata-Ambrosia dumosa plant alliance in the Mojave Desert 36 years after construction. The 97-m wide corridor contained a central dirt road and buried aqueduct pipeline. We established transects at 0 m (road verge), 20 m and 40 m into the disturbance corridor, and at 100 m in undisturbed habitat (the control). Although total numbers of shrubs per transect did not vary significantly with distance from the verge, canopy cover of shrubs, species richness, and species diversity were higher in the control than at the verge and other distances. Canopy cover of common shrubs (Ericameria nauseosa, Ambrosia salsola, A. dumosa, L. tridentata, Grayia spinosa) and perennial grasses (Elymus elymoides, Poa secunda) also varied significantly by location. Discriminant analysis clearly separated the four distances based on plant composition. Patterns of recovery were bidirectional: secondary succession from the control into the disturbance corridor and inhibition from the verge in the direction of the control. Time estimated for species composition to resemble the control is dependent on location within the disturbance corridor and could be centuries at the road verge. Our findings have applications to other deserts.

Spatial modulation of the Fermi level by coherent illumination of undoped GaAs

Science.gov (United States)

Nolte, D. D.; Olson, D. H.; Glass, A. M.

1989-11-01

The Fermi level in undoped GaAs has been modulated spatially by optically quenching EL2 defects. The spatial gradient of the Fermi level produces internal electric fields that are much larger than fields generated by thermal diffusion alone. The resulting band structure is equivalent to a periodic modulation-doped p-i-p structure of alternating insulating and p-type layers. The internal fields are detected via the electro-optic effect by the diffraction of a probe laser in a four-wave mixing geometry. The direct control of the Fermi level distinguishes this phenomenon from normal photorefractive behavior and introduces a novel nonlinear optical process.

Identification of priority conservation areas and potential corridors for jaguars in the Caatinga biome, Brazil.

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Ronaldo Gonçalves Morato

Full Text Available The jaguar, Panthera onca, is a top predator with the extant population found within the Brazilian Caatinga biome now known to be on the brink of extinction. Designing new conservation units and potential corridors are therefore crucial for the long-term survival of the species within the Caatinga biome. Thus, our aims were: 1 to recognize suitable areas for jaguar occurrence, 2 to delineate areas for jaguar conservation (PJCUs, 3 to design corridors among priority areas, and 4 to prioritize PJCUs. A total of 62 points records of jaguar occurrence and 10 potential predictors were analyzed in a GIS environment. A predictive distributional map was obtained using Species Distribution Modeling (SDM as performed by the Maximum Entropy (Maxent algorithm. Areas equal to or higher than the median suitability value of 0.595 were selected as of high suitability for jaguar occurrence and named as Priority Jaguar Conservation Units (PJCU. Ten PJCUs with sizes varying from 23.6 km2 to 4,311.0 km2 were identified. Afterwards, we combined the response curve, as generated by SDM, and expert opinions to create a permeability matrix and to identify least cost corridors and buffer zones between each PJCU pair. Connectivity corridors and buffer zone for jaguar movement included an area of 8.884,26 km2 and the total corridor length is about 160.94 km. Prioritizing criteria indicated the PJCU representing c.a. 68.61% of the total PJCU area (PJCU # 1 as of high priority for conservation and connectivity with others PJCUs (PJCUs # 4, 5 and 7 desirable for the long term survival of the species. In conclusion, by using the jaguar as a focal species and combining SDM and expert opinion we were able to create a valid framework for practical conservation actions at the Caatinga biome. The same approach could be used for the conservation of other carnivores.

Spatial variation of mercury levels in nesting Bonelli's eagles from Southwest Portugal: effects of diet composition and prey contamination

Energy Technology Data Exchange (ETDEWEB)

Palma, Luis [CCMAR, Universidade do Algarve, FCMA, Campus de Gambelas, 8005-139 Faro (Portugal)]. E-mail: lpalma@ualg.pt; Beja, Pedro [CCMAR, Universidade do Algarve, FCMA, Campus de Gambelas, 8005-139 Faro (Portugal); ERENA, Av. Visconde Valmor, 11-3, 1000-289 Lisbon (Portugal); Tavares, Paula C. [IMAR, Universidade dos Acores, Departamento de Pescas e Oceanografia, Cais Sta. Cruz, 9901-862 Horta (Portugal); Monteiro, Luis R. [IMAR, Universidade dos Acores, Departamento de Pescas e Oceanografia, Cais Sta. Cruz, 9901-862 Horta (Portugal)

2005-04-01

Mercury (Hg) was determined in adult Bonelli's eagles (Hieraaetus fasciatus) and their avian prey, from samples of feathers collected between 1992 and 2001 at the nesting sites of 21 pairs in Southwest Portugal. Eagle Hg levels showed great variation, reflecting primarily differences in diet composition and food chain biomagnification. Concentrations were positively correlated with the dietary proportion of insectivorous and omnivorous birds (e.g. egrets, corvids and thrushes), with very low levels for pairs feeding mainly on herbivores (e.g. rabbits, pigeons and partridges). Differences in prey contamination among breeding territories added to dietary effects in determining variation of Hg levels in eagles, shaping a spatial pattern that was largely consistent with a source of contamination in a coal-burning power-plant lying upwind of the study area. Despite this presumed contamination, Hg levels seemed to be of little concern to this eagle population, though there might be subtle deleterious effects on the reproductive output of a few pairs. This study emphasizes the need to account for dietary effects when biomonitoring Hg contamination using birds of prey. - The effects of diet composition and prey contamination added up to determine the spatial variation of Hg levels in breeding Bonelli's eagles.

Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

Science.gov (United States)

Bi, Qifang; Azman, Andrew S; Satter, Syed Moinuddin; Khan, Azharul Islam; Ahmed, Dilruba; Riaj, Altaf Ahmed; Gurley, Emily S; Lessler, Justin

2016-02-01

Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets) near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs) to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98), type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00), and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00) exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a cholera endemic

Micro-scale Spatial Clustering of Cholera Risk Factors in Urban Bangladesh.

Directory of Open Access Journals (Sweden)

Qifang Bi

2016-02-01

Full Text Available Close interpersonal contact likely drives spatial clustering of cases of cholera and diarrhea, but spatial clustering of risk factors may also drive this pattern. Few studies have focused specifically on how exposures for disease cluster at small spatial scales. Improving our understanding of the micro-scale clustering of risk factors for cholera may help to target interventions and power studies with cluster designs. We selected sets of spatially matched households (matched-sets near cholera case households between April and October 2013 in a cholera endemic urban neighborhood of Tongi Township in Bangladesh. We collected data on exposures to suspected cholera risk factors at the household and individual level. We used intra-class correlation coefficients (ICCs to characterize clustering of exposures within matched-sets and households, and assessed if clustering depended on the geographical extent of the matched-sets. Clustering over larger spatial scales was explored by assessing the relationship between matched-sets. We also explored whether different exposures tended to appear together in individuals, households, and matched-sets. Household level exposures, including: drinking municipal supplied water (ICC = 0.97, 95%CI = 0.96, 0.98, type of latrine (ICC = 0.88, 95%CI = 0.71, 1.00, and intermittent access to drinking water (ICC = 0.96, 95%CI = 0.87, 1.00 exhibited strong clustering within matched-sets. As the geographic extent of matched-sets increased, the concordance of exposures within matched-sets decreased. Concordance between matched-sets of exposures related to water supply was elevated at distances of up to approximately 400 meters. Household level hygiene practices were correlated with infrastructure shown to increase cholera risk. Co-occurrence of different individual level exposures appeared to mostly reflect the differing domestic roles of study participants. Strong spatial clustering of exposures at a small spatial scale in a