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Rapid develop ment of the mult imedia and the associated technologies urge the processing of a huge database of video clips. The processing efficiency depends on the search methodologies utilized in the video processing system. Use of inappropriate search methodologies may make the processing system ineffective. Hence, an effective video retrieval system is an essential pre-requisite for searching relevant videos from a huge collection of videos. In this paper, an effective content based video retrieval system based on some dominant features such as motion, color and edge is proposed. The system is evaluated using the video clips of format MPEG-2 and then precision-recall is determined for the test clip.

Numerous metrics describing landscape patterns have been used to explain landscape-scale habitat selection by birds. The myriad metrics, their complexity, and inconsistent responses to them by birds have led to a lack of clear recommendations for managing land for desired species. The amount of a target land cover type in the landscape (percentage cover) often has been a useful indicator of the likelihood of species occurrence or of habitat selection; is it also a more adequate and parsimonious measure for explaining species distributions than patch size or more complex measures of landscape configuration? We examined responses of 6 woodland-interior bird species to the percentage tree cover within prescribed areas and to patch size, edge density, and other metrics. We examined responses in 2 landscapes: a mixed woodland-savanna and an eastern deciduous forest. For these 6 species, percentage tree cover explained bird occurrence as well as or better than other measures in both study areas. We the...

This case study was conducted to quantify the effects of urban greenspace patterns on particle matter (PM) concentration in Zhengzhou, China by using redundancy and variation partitioning analysis. Nine air-quality monitoring stations (AQMS) were selected as the central points. Six distances of 1 km, 2 km, 3 km, 4 km, 5 km, and 6 km were selected as the side lengths of the squares with each AQMS serving as the central point, respectively. We found: (1) the fine size of PM (PM2.5) and coarse size of PM (PM10) among four seasons showed significant differences; during winter, the concentration of PM2.5 and PM10 were both highest, and PM2.5 and PM10 concentration in summer were lowest. (2) To effectively reduce the PM2.5 pollution, the percentage of greenspace, the differences in areas among greenspace patches, and the edge complexity of greenspace patches should be increased at distances of 2 km and 3 km. To effectively reduce PM10, the percentage of greenspace at a distance of 4 km, the edge density at distances of 2 km and 4 km, and the average area of greenspace patches at a distance of 1 km should be increased. (3) Greenspace pattern significantly affected PM2.5 at a distance of 3 km, and PM10 at a distance of 4 km. From shorter distance to longer distance, the proportion of variance explained by greenspace showed a decline–increase–decline–increase trend for PM2.5, and a decline–increase–decline trend for PM10. At shorter distances, the composition of greenspace was more effective in reducing the PM pollution, and the configuration of greenspace played a more important role at longer distances. The results should lead to specific guidelines for more cost-effective and environmentally sound greenspace planning.

A study is presented showing how three state-of-the-art algorithms from the Face Recognition Vendor Test 2006 (FRVT 2006) are effected by factors related to face images and people. The recognition scenario compares highly controlled images to images taken of people as they stand before a camera in settings such as hallways and outdoors in front of buildings. A Generalized Linear Mixed Model (GLMM) is used to estimate the probability an algorithm successfully verifies a person conditioned upon the factors included in the study. The factors associated with people are: Gender, Race, Age and whether they wear Glasses. The factors associated with images are: the size of the face, edge density and region density. The setting, indoors versus outdoors, is also a factor. Edge density can change the estimated probability of verification dramatically, for example from about 0.15 to 0.85. However, this effect is not consistent across algorithm or setting. This finding shows that simple measurable factors are capable of characterizing face quality; however, these factors typically interact with both algorithm and setting.

A method for constructing protein semantic networks using MEDLINE abstracts is proposed. The publications retrieved by the context search for protein names (relevant) and the related publications were used. The proposed method is based on estimation of semantic connectivity between proteins. The connectivity score was calculated as a function of the number of relevant or related papers found for a pair of proteins. This score was used to construct a semantic network for 150 human proteins belonging to five different metabolic pathways. Analysis of the network demonstrated that the proteins involved in associated molecular processes formed the subgraphs with a high edge density.

Every 3-graph in which no four vertices are independent and no four vertices span precisely three edges must have edge density $\geq4/9(1-o(1))$. This bound is tight. The proof is a rather elaborate application of Cauchy-Schwarz-type arguments presented in the framework of flag algebras. We include further demonstrations of this method by re-proving a few known tight results about hypergraph Turan densities and significantly improving numerical bounds for several problems for which the exact value is not known yet.

In this study, the quantification method of the cutting-edge density is proposed because of its close relation to the grinding mechanism. The cutting-edge density depends upon not only the grain distribution but also the thickness of effective cutting-edge layer. Therefore, the quantification of the cutting-edge density requires measuring not only the profile but also the grinding force. The thickness of effective cutting-edge layer can be determined based on the grain distribution, the grinding force and the stiffness of a grinding wheel. From applied result of the proposed method for the actual grinding process, the cutting-edge density and the effective cutting-edges layer is determined appropriately corresponding to the change in the working surface condition.

For a fixed ρ ∈ [0, 1], what is (asymptotically) the minimal possible density g3(ρ) of triangles in a graph with edge density ρ? We completely solve this problem by proving thatwhere$t\df \lfloor 1/(1-\rho)\rfloor$is the integer such that$\rho\in\bigl[ 1-\frac 1t,1-\frac 1{t+1}\bigr]$.

We introduce a new variant of Szemer\'edi's regularity lemma which we call the "sparse regular approximation lemma" (SRAL). The input to this lemma is a graph $G$ of edge density $p$ and parameters $\epsilon, \delta$, where we think of $\delta$ as a constant. The goal is to construct an $\epsilon$-regular partition of $G$ while having the freedom to add/remove up to $\delta |E(G)|$ edges. As we show here, this weaker variant of the regularity lemma already suffices for proving the graph removal lemma and the hypergraph regularity lemma, which are two of the main applications of the (standard) regularity lemma. This of course raises the following question: can one obtain quantitative bounds for SRAL that are significantly better than those associated with the regularity lemma? Our first result answers the above question affirmatively by proving an upper bound for SRAL given by a tower of height $O(\log 1/p)$. This allows us to reprove Fox's upper bound for the graph removal lemma. Our second result is a matching lower bound for SRAL showing that a tower of height $\Omega(\log 1/p)$ is unavoidable. We in fact prove a more general multicolored lower bound which is essential for proving lower bounds for the hypergraph regularity lemma.

Effects of scale on relationships between organisms and their environment are of considerable contemporary interest. We evaluated Breeding Bird Survey data and landscape measures derived from aerial photographs to examine how relationships changed over a continuous range of 16 spatial scales. Analyses incorporated 1985–1994 data (average number of birds/stop/yr) for eight flycatcher species (Tyrannidae) for each of 50 stops on 198 Breeding Bird Survey transects in the Central Plains. Associations of bird abundances with landscape variables changed gradually with small changes in scale. Edge density had significant associations with abundances of Eastern Phoebes (Sayornis phoebe), Great Crested Flycatchers (Myiarchus crinitus), and Western Kingbirds (Tyrannus verticalis) suggesting this landscape characteristic is important for certain breeding flycatcher species. Fractal dimension and principal component II, the latter reflecting amounts of closed forest versus open country, exhibited the highest...

The Turán density $\pi(\cal F)$ of a family $\cal F$ of $r$-graphs is the limit as $n\to\infty$ of the maximum edge density of an $\cal F$-free $r$-graph on $n$ vertices. Erdős [Israel J. Math, 2 (1964):183—190] proved that no Turán density can lie in the open interval $(0,r!/r^r)$. Here we show that any other open subinterval of $[0,1]$ avoiding Turán densities has strictly smaller length. In particular, this implies a conjecture of Grosu [arXiv:1403.4653, 2014].

Wheel structure has a critical influence on grinding performance especially active cuttingedge density. Experiments were carried out to find out the relationshipbetween active and staticcutting edge density. It was found that there are many more active cutting edges in grinding thanexpected based on chip thickness formulae mainly due to wheel deflection in grinding.

A novel image-based defect identification and coding technique has been proposed for fluted ingots, which are used for the production of locomotive wheels. The edge density map has been used for defect identification and an object-based coding approach has been applied for the storage of defective ingots. The complete scheme has been implemented in one of the integrated steel plants of India.

Given 0 < p < 1, we prove that a pseudorandom graph G with edge density p and sufficiently large order has the following property: Consider any red/blue-coloring of the edges of G and let r denote the proportion of edges which have the color red. Then there is a Hamilton cycle C so that the proportion of red edges of C is close to r. The analogue also holds for perfect matchings instead of Hamilton cycles. We also prove a bipartite version which is used elsewhere to give a minimum-degree condition for the existence of a Hamilton cycle in a 3-uniform hypergraph.

High triangularity regimes, approaching double null, have become more important recently. H-mode access and edge stability are affected by the close proximity of the second X-point to the last closed flux surface, but more experimental evidence is needed. Inter-machine comparisons of MAST with ASDEX Upgrade (AUG) and NSTX confirm the reduction of the H-mode power threshold in the true double null configuration (C-DN), first reported on MAST. A more negative radial edge electric field in L-mode observed on MAST and ASDEX Upgrade may be connected to the improved H-mode access. About twice the power density is needed on MAST to achieve edge pressures similar to AUG in L- and H-modes. However, on MAST the pressure is dominated by the edge density in H-mode. So far, in single null (SN) ELMs have not been observed on MAST with neutral beam heating powers PNBI ≤ 2 MW, due to the different edge profiles in SN H-mode. This is supported by the modelling of the stability of the measured edge profiles against ideal peeling–ballooning.

The behavior of several landscape pattern metrics were tested against various pattern scenarios generated by neutral landscape models, including number of classes, scale-map extent, scale-resolution, class proportion, aggregation level-RULE, and aggregation level-SimMap. The results demonstrate that most of the metrics are sensitive to certain pattern scenarios, yet are not sensitive to others; therefore, none of them is appropriate for all aspects of a landscape pattern. Despite these limitations, some of these metrics are recommended for future use, which include total number of patches, average patch size, total edge density, double-logged fractal, contagion, and aggregation index. Special attention should be paid to the relationships between metric values and ecological processes rather than the numbers themselves. es.

This paper explores an addition to theory in urban geography pertaining to spatio‐temporal dynamics. Remotely sensed data on the historical extent of urban areas were used in a spatial metrics analysis of geographical form of towns and cities in the Central Valley of California (USA). Regularities in the spatio‐temporal pattern of urban growth were detected and characterized over a hundred year period. To test hypotheses about variation over geographical scale, multiple spatial extents were used in examining a set of spatial metric values including an index of contagion, the mean nearest neighbor distance, urban patch density and edge density. Through changes in these values a general temporal oscillation between phases of diffusion and coalescence in urban growth was revealed. Analysis of historical datasets revealed preliminary evidence supporting an addition to the theory of urban growth dynamics, one alluded to in some previous research, but not well developed. The empirical results and findings provi...

Estimates of survival and cause-specific mortality of white-tailed deer (Odocoileus virginianus) fawns are important to population management. We quantified cause-specific mortality, survival rates, and habitat characteristics related to fawn survival in a forested landscape and an agricultural landscape in central Pennsylvania. We captured and radiocol-lared neonatal (

Given an undirected graph G=(V,E) and a nonempty subset X⊆V, the edge density of X is given by ρ(X)=|V||EX|/|X||V⧹X|, where EX is the set of all edges with one end in X and the other end in V⧹X. It is known that the algebraic connectivity of G, denoted by a(G), satisfies a(G)⩽minX⊆Vρ(X). In this paper we study the graphs G for which equality holds in the above inequality.

Although cell reshaping is fundamental to the mechanics of epithelia, technical barriers have prevented the methods of mechanics from being used to investigate it. These barriers have recently been overcome by the cell-based finite element formulation of Chen and Brodland. Here, parameters to describe the fabric of an epithelium in terms of cell shape and orientation and cell edge density are defined. Then, rectangular "patches" of model epithelia having various initial fabric parameters are generated and are either allowed to anneal or are subjected to one of several patterns of in-plane deformation. The simulations show that cell reshaping lags the deformation history, that it is allayed by cell rearrangement and that it causes the epithelium as a whole to exhibit viscoelastic mechanical properties. Equations to describe changes in cell shape due to annealing and in-plane deformation are presented.

We show that, for a natural notion of quasirandomness in $k$-uniform hypergraphs, any quasirandom $k$-uniform hypergraph on $n$ vertices with constant edge density and minimum vertex degree $\Omega(n^{k-1})$ contains a loose Hamilton cycle. We also give a construction to show that a $k$-uniform hypergraph satisfying these conditions need not contain a Hamilton $\ell$-cycle if $k-\ell$ divides $k$. The remaining values of $\ell$ form an interesting open question., Comment: 18 pages. Accepted for publication in Random Structures & Algorithms

We study the lower tail large deviation problem for subgraph counts in a random graph. Let $X_H$ denote the number of copies of $H$ in an Erd\H{o}s-R\'enyi random graph $\mathcal{G}(n,p)$. We are interested in estimating the lower tail probability $\mathbb{P}(X_H \le (1-\delta) \mathbb{E} X_H)$ for fixed $0 < \delta < 1$. Thanks to the results of Chatterjee, Dembo, and Varadhan, this large deviation problem has been reduced to a natural variational problem over graphons, at least for $p \ge n^{-\alpha_H}$ (and conjecturally for a larger range of $p$). We study this variational problem and provide a partial characterization of the so-called "replica symmetric" phase. Informally, our main result says that for every $H$, and $0 < \delta < \delta_H$ for some $\delta_H > 0$, as $p \to 0$ slowly, the main contribution to the lower tail probability comes from Erd\H{o}s-R\'enyi random graphs with a uniformly tilted edge density. On the other hand, this is false for non-bipartite $H$ and $\delta$ close to 1., Comment: 15 pages, 5 figures, 1 table

A traffic states detection method is proposed to represent the road traffic conditions accurately and reduce labor intensive monitoring work in this paper. The edge of image, which is named as edge characteristic, is applied to describe the number of vehicles running on the road, and the average density of vehicle edge pixels is used to substitute the road occupation ratio. Meanwhile block matching method is used for estimating the speed of traffic flow. According the extracted feature parameters, a classifier is designed to classify the traffic states in three categories (congested, slow, and smooth). The experimental results showed the proposed algorithm is robust. Keywords-Traffic state detection; Traffic flow speed; Block matching; Vehicle edge density; Background subtract

We study the asymptotics of large simple graphs constrained by the limiting density of edges and the limiting subgraph density of an arbitrary fixed graph $H$. We prove that, for all but finitely many values of the edge density, if the density of $H$ is constrained to be slightly higher than that for the corresponding Erd\H{o}s-R\'enyi graph, the typical large graph is bipodal with parameters varying analytically with the densities. Asymptotically, the parameters depend only on the degree sequence of $H$.

The effect of the electron temperature ( T e ) on the edge particle transport in the pedestal is analyzed during the density build-up after the L-H transition. Electron cyclotron resonance heating was used to vary the pedestal temperature during the density evolution between subsequent H-mode phases. Although the pedestal T e and its gradients could be varied by a factor of 2, almost no change in the edge density evolution is observed within the measurement uncertainties. ASTRA was used to interpret the measurements and to analyze the dependence of the pedestal particle transport on the T e profile. Thermo-diffusion seems to play a minor role in the pedestal.

The use of medical images by medical practitioners has increased to an extent that computers have become a necessity in the image processing and analysis. This research investigates if the Edge density and Local Directional Pattern can be used to characterize medical images. The performance of the Edge density and Local Directional Pattern features is assessed by finding their accuracy to retrieve images of the same group from a database. The combination of the Edge density and Local Directional Pattern features has shown to produce good results in both, classification of medical images and image retrieval. For the classification using the nearest neighbor and 5-nearest neighbor techniques yielded 98.2 % and 99.6 % classification success rates respectively and 99.4 % for image retrieval. The results achieved in this research work are comparable to other approaches used in literature.

A feature of human viewpoint movement in reading English has been pointed out from the psychological aspect, namely, that the first viewpoint on the word concentrates at the center of the word. This paper focuses on the three factors that seem to induce the above feature of viewpoint movement in reading English, which are the use of foveal vision, the use of the edge density of letters (characters), and the use of the space between words. The movement of the viewpoint is realized on a computer, and the major factor responsible for the feature that the viewpoint concentrates at the center of the word is examined. The attention region is defined in realizing viewpoint movement that is restricted. The viewpoint is actually moved for the cases where each of the three factors is followed or not followed, and the features of viewpoint movement are examined. The features of viewpoint movement realized on the basis of each factor are compared to those of previously reported human viewpoint movement. Based on the comparison, it is shown that the three factors are actually inducing the feature that the viewpoint concentrates at the center of the word. By varying the size of the attention region, the effect on the viewpoint movement is examined, and it is shown that the size of the attention region is the factor that manifests the features of human viewpoint movement. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 85(8): 34–43, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.10064

Although both the transport barriers in the plasma interior and edge, namely internal transport barrier (ITB) and H-mode, are simultaneously required to sustain high-β and improved confinement in steady state, experimental observations suggest that theL-H transition and ITB formation are independent phenomena with different formation conditions, and they often exhibit apparent contradictions to each other. Accordingly, the compatibility conditions of edge and internal barrier formation have been investigated in JT-60U. The L-H threshold power is substantially increased in strong ITB plasmas, and high-performance discharges often persist in L-mode. On the other hand, the ITB formation power increases in H-mode plasmas. It was found, however, that the L-H transition criteria expressed in terms of the edge quantities are similar in plasmas with and without the ITB, and the edge density is extremely low in strong ITB plasmas. It has also been demonstrated in JT-60U that the controlled degradation of the ITB quality, in terms of the changes of toroidal torque input, results in an increase of edge density and induces theL-H transition. Therefore, the quality of ITB modifies the L-H transition threshold power, indicating that the additional `hidden' parameter is present in ITB plasmas. Other approaches of dynamically controlling the L-H transition in ITB plasmas, such as the triangularity ramp developed in JT-60U, are also discussed in this paper.

High-confinement (H-mode) plasma was achieved by injecting frozen deuterium pellets in the experimental advanced superconducting tokamak (EAST). Interesting phenomena of the simple and two-stage low–high confinement (L–H) transitions are observed in EAST with radio frequency heating after pellet injection. The results of the L–H transitions induced by pellets are discussed in detail with different theories. It is found that pellet injection in EAST can reduce the power threshold of the H-mode. Furthermore, the pellet-induced edge density gradient is an important parameter affecting the L–H transition. This investigation would be useful for the analysis of the feasibility of H-mode access by pellet injection in future devices, such as ITER.

A model is presented for the calculation of the characteristic scale lengths from transport considerations in the edge pedestal region of high confinement (H-mode) plasmas. The model is based on the requirements of heat and particle removal through the edge. Atomic physics effects on edge density and temperature gradient scale lengths are taken into account. An empirical fit for the width of the edge pedestal transport barrier is employed. Model problem calculations indicate that the model predicts the magnitudes and some trends of characteristic gradient scale lengths observed in current experiments.

A remarkable reduction of the L-H threshold power was observed in JT-60U under the W-shaped pumped divertor geometry, in comparison with the results for the previous open divertor. The density range was extended to 0.6nGWL ( = Ip/πa2), where a stronger than linear density dependence was found. A reduction of the radiation power and edge temperature as well as a nonlinear increase in edge density were also observed. The poloidal distribution of the neutral particle density was first examined in this work, and it was found that compression of neutral particles near the X-point or loss of homogeneity on a flux surface produced by the modification of the divertor geometry may be an influential determinant of the L-H threshold power.

Recently, there has been increased interest in the ratio nS/nC, where nS and nC are the separatrix and pedestal densities, respectively. A semi-empirical model for this ratio is proposed which puts particular emphasis on the role of edge physics. The empirical elements of the model and the detailed comparison with data rely on the extensive edge density database established at ASDEX Upgrade. The derived scaling can be cast into a form where nS/nC is essentially determined by the proximity to the Greenwald limit.

The effect of tokamak toroidal geometry on producing edge density and parallel flow asymmetries and its influence on Marfe localization are studied. In the presence of a large poloidal rotation, the density asymmetry is peaked at the high field side of tokamak edge and this becomes the seed of a condensation process, which triggers a Marfe there finally.

Steady-state H-modes have been obtained on TdeV both with ECRH and Lower Hybrid heating. Power thresholds are comparable with those predicted by the ITER scaling laws. A very pronounced threshold in edge density is observed, below which no L–H transitions occur. H–L transitions occur at significantly lower values of edge density. When the edge density exceeds the threshold, H-modes are produced both with an outboard limiter and with the divertor baffle within one density scrape-off layer of the separatrix. In the former case, confinement was degraded, in the latter, it was improved.

A meaningful interpretation of landscape metrics is possible only when the limitations of each measure are fully understood, the range of attainable values is known, and the user is aware of potential shifts in the range of values due to characteristics of landscape patches. To examine the behavior of landscape metrics, we generated artificial landscapes that mimicked fragmentation processes while controlling the size and shape of patches in the landscape and the mode of disturbance growth. We developed nine series of increasingly fragmented landscapes and used these to investigate the behavior of edge density, contagion, mean nearest neighbor distance, mean proximity index, perimeter-area fractal dimension, and mass fractal dimension. We found that most of the measures were highly correlated, especially contagion and edge density, which had a near-perfect inverse correspondence. Many of the measures were linearly-associated with increasing disturbance until the proportion of disturbance on the landscape was approximately 0.40, with non-linear associations at higher proportions. None of the measures was able to differentiate between landscape patterns characterized by dispersed versus aggregated patches. The highest attainable value of each measure was altered by either patch size or shape, and in some cases, by both attributes. We summarize our findings by discussing the utility of each metric.

What is the probability that the number of triangles in $\mathcal{G}_{n,p}$, the Erd\H{o}s-R\'enyi random graph with edge density $p$, is at least twice its mean? Writing it as $\exp[- r(n,p)]$, already the order of the rate function $r(n,p)$ was a longstanding open problem when $p=o(1)$, finally settled in 2012 by Chatterjee and by DeMarco and Kahn, who independently showed that $r(n,p)\asymp n^2p^2 \log (1/p)$ for $p \gtrsim \frac{\log n}n$; the exact asymptotics of $r(n,p)$ remained unknown. The following variational problem can be related to this large deviation question at $p\gtrsim \frac{\log n}n$: for $\delta>0$ fixed, what is the minimum asymptotic $p$-relative entropy of a weighted graph on $n$ vertices with triangle density at least $(1+\delta)p^3$? A beautiful large deviation framework of Chatterjee and Varadhan (2011) reduces upper tails for triangles to a limiting version of this problem for fixed $p$. A very recent breakthrough of Chatterjee and Dembo extended its validity to $n^{-\alpha}\ll p \ll 1$ for an explicit $\alpha>0$, and plausibly it holds in all of the above sparse regime. In this note we show that the solution to the variational problem is $\min\{\frac12 \delta^{2/3}\,,\, \frac13 \delta\}$ when $n^{-1/2}\ll p \ll 1$ vs. $\frac12 \delta^{2/3}$ when $n^{-1} \ll p\ll n^{-1/2}$ (the transition between these regimes is expressed in the count of triangles minus an edge in the minimizer). From the results of Chatterjee and Dembo, this shows for instance that the probability that $\mathcal{G}_{n,p}$ for $ n^{-\alpha} \leq p \ll 1$ has twice as many triangles as its expectation is $\exp[-r(n,p)]$ where $r(n,p)\sim \frac13 n^2 p^2\log(1/p)$. Our results further extend to $k$-cliques for any fixed $k$, as well as give the order of the upper tail rate function for an arbitrary fixed subgraph when $p\geq n^{-\alpha}$., Comment: 15 pages

Landscape ecology studies on pest control have focused mainly on annual crops and natural enemies, whereas more studies measuring pest pressure on perennial crops are needed. The relationships between the abundance and damage by Bactrocera oleae (Rossi) and different landscape indices were analyzed using data gathered by a regional network during 2009, 2010 and 2011 in Jaén, Spain. Eleven indices of landscape composition and configuration calculated at six different spatial scales (radii of 500, 600, 750, 1000, 1500 and 2000m) were used in correlation analyses. Significant correlations between abundance and some indices were observed primarily during Julian days 236-264 (24 August to 21 September) 2010. These correlations were negative with edge density, the Shannon landscape diversity index and the number of patches, and were positive with patch size standard deviation and mean patch size. Linear mixed-effects models were used to identify the indices most strongly related to the abundance of olive flies. These indices were mean patch size, edge density at 500-750m and the Shannon landscape diversity index, as well as the number of patches at 1000-2000m. These results suggest that greater landscape complexity may contribute to reduced numbers of B. oleae. More studies are needed to establish how to reduce olive fruit fly damage. © 2013 The Royal Entomological Society.

Measurements were carried out of saccadic eye movements made during brief (3 s) examination of images which the observer was asked to identify. Each image was identified in three forms: low-pass filtered, high-pass filtered, and unfiltered. The analysis of the eye-movement patterns was based on the locations of fixations made during examination of the images, for which purpose a least-squares measure of similarity between two sets of locations was introduced. It is shown that there is a high degree of similarity between fixations made by the same observer to the different versions of a given image and that for a given image there is a high degree of similarity between fixations made by the eighteen observers who participated in the experiments. The similarities are greater for the initial 1.5 s than for the full viewing period of 3 s. The similarity between the locations of fixations and those of selected image features such as local contrast, high-spatial-frequency content, and edge density was also examined. It is shown that there is only weak similarity between the locations of fixations and those of any given local image feature, and the tendency of observers to fixate centrally on the image is identified as the principal reason for the low similarity values. It is shown that if the nonuniform distribution of eye movements is taken into account, significant similarities are found between the locations of fixations and those of certain image features, such as edge density.

The spectrum of n = 0 Alfven modes is calculated analytically and numerically in cylindrical and toroidal geometries. It includes global Alfven eigenmodes (GAEs) and surface modes (SMs) of the fast magnetoacoustic wave. These modes are not induced by toroidicity. The n = 0 GAEs owe their existence to shear. The frequency spacing between different radial and poloidal modes and the correlation of eigenfrequencies with changes in the edge density are examined and found to be in complete agreement with experimental observations of what have been named the 'Alfven frequency modes' (AFMs) so far (Chang, Z., et al., Nucl. Fusion 35 (1995) 1469). Although the eigenfrequency is related to the edge density, the n = 0 GAEs (AFMs) are not necessarily edge localized.

The chiral Tomonaga–Luttinger model is obtained as the low-energy limit of the Chern–Simons theory for fractional quantum Hall effect systems with ν=1/ φ for odd φ . In particular, we recover the Kac-Moody algebra for the creation and annihilation operators of the edge density waves and the bosonization formula for the electronic operator at the edge.

Percolation describes the sudden emergence of large-scale connectivity as edges are added to a lattice or random network. In the Bohman-Frieze-Wormald model (BFW) of percolation, edges sampled from a random graph are considered individually and either added to the graph or rejected provided that the fraction of accepted edges is never smaller than a decreasing function with asymptotic value of $\ensuremath{\alpha}$, a constant. The BFW process has been studied as a model system for investigating the underlying mechanisms leading to discontinuous phase transitions in percolation. Here we focus on the regime $\ensuremath{\alpha}\ensuremath{\in}[0.6,0.95]$ where it is known that only one giant component, denoted ${\mathrm{C}}_{1}$, initially appears at the discontinuous phase transition. We show that at some point in the supercritical regime ${\mathrm{C}}_{1}$ stops growing and eventually a second giant component, denoted ${\mathrm{C}}_{2}$, emerges in a continuous percolation transition. The delay between the emergence of ${\mathrm{C}}_{1}$ and ${\mathrm{C}}_{2}$ and their asymptotic sizes both depend on the value of $\ensuremath{\alpha}$ and we establish by several techniques that there exists a bifurcation point ${\ensuremath{\alpha}}_{c}=0.763\ifmmode\pm\else\textpm\fi{}0.002$. For $\ensuremath{\alpha}\ensuremath{\in}[0.6,{\ensuremath{\alpha}}_{c})$, ${\mathrm{C}}_{1}$ stops growing the instant it emerges and the delay between the emergence of ${\mathrm{C}}_{1}$ and ${\mathrm{C}}_{2}$ decreases with increasing $\ensuremath{\alpha}$. For $\ensuremath{\alpha}\ensuremath{\in}({\ensuremath{\alpha}}_{c},0.95]$, in contrast, ${\mathrm{C}}_{1}$ continues growing into the supercritical regime and the delay between the emergence of ${\mathrm{C}}_{1}$ and ${\mathrm{C}}_{2}$ increases with increasing $\ensuremath{\alpha}$. As we show, ${\ensuremath{\alpha}}_{c}$ marks the minimal delay possible between the emergence of ${\mathrm{C}}_{1}$ and ${\mathrm{C}}_{2}$ (i.e., the smallest edge density for which ${\mathrm{C}}_{2}$ can exist). We also establish many features of the continuous percolation of ${\mathrm{C}}_{2}$ including scaling exponents and relations.

Numerical simulations of L-mode plasma turbulence in the Scrape Off Layer of MAST are presented. Relevant features of the boundary plasma, such as the thickness of the density layer or the statistics of the fluctuations are related to the edge density and temperature, plasma current and parallel connection length. It is found that the density profile is weakly affected by the edge density, it broadens when the current or the temperature are decreased while the connection length has the opposite effect. The statistics of the turbulence is relatively insensitive to variations of all the edge parameters and show a certain degree of universality. Effective transport coefficients are calculated for several plasma conditions and display a strong nonlinear dependence on the parameters and on the radial variable. Finally, it is shown how the perpendicular particle fluxes in the Scrape Off Layer are related to the edge parameters., Comment: 21 pages, 6 figures

We study the number of $k$-element sets $A \subset \{1,\ldots,N\}$ with $|A + A| \leq K|A|$ for some (fixed) $K > 0$. Improving results of the first author and of Alon, Balogh, Samotij and the second author, we determine this number up to a factor of $2^{o(k)} N^{o(1)}$ for most $N$ and $k$. As a consequence of this and a further new result concerning the number of sets $A \subset \mathbf{Z}/N\mathbf{Z}$ with $|A +A| \leq c |A|^2$, we deduce that the random Cayley graph on $\mathbf{Z}/N\mathbf{Z}$ with edge density~$\frac{1}{2}$ has no clique or independent set of size greater than $\big( 2 + o(1) \big) \log_2 N$, asymptotically the same as for the Erd\H{o}s-R\'enyi random graph. This improves a result of the first author from 2003 in which a bound of $160 \log_2 N$ was obtained. As a second application, we show that if the elements of $A \subset \mathbf{N}$ are chosen at random, each with probability $1/2$, then the probability that $A+A$ misses exactly $k$ elements of $\mathbf{N}$ is equal to $\big( 2 + o(1) \big)^{-k/2}$ as $k \to \infty$., Comment: 30 pages, to appear in Combinatorica. Minor changes made following helpful suggestions by the referees