Deviation Map Research Articles

A Vehicle License Plate Recognition System Using Morphological ROI (Region of Interest) Map Generated from Morphology Operation

In this paper, morphology features are used to improve license plate region and Morphological ROI (MROI) map that consists of a standard deviation map of open and close images is proposed. Unlike conventional morphology techniques, MROI map is used to improve the detection of license plate in a complex background. Furthermore, distribution of the MROI map was analyzed to determine a threshold level, generate binary code images, and finally, determine the vehicle license plate region by using the features of the plate such as aspect ratio and vertical edge intensity. The proposed method could improve the error rate by approximately 4-7% depending on the pattern of the images.

Diagnostic Ability of Retinal Nerve Fiber Layer Thickness Deviation Map for Localized and Diffuse Retinal Nerve Fiber Layer Defects.

Purpose. To evaluate the diagnostic ability of the retinal nerve fiber layer (RNFL) deviation map for glaucoma with localized or diffuse RNFL defects. Methods. Eyes of 139 glaucoma patients and 165 healthy subjects were enrolled. All participants were imaged with Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA). A RNFL defect was defined as at least 10 contiguous red (<1% level) superpixels in RNFL deviation map. The area, location, and angular width of RNFL defects were automatically measured. We compared sensitivities, specificities, and area under the receiver operating characteristic curves (AUCs) of RNFL deviation map and circumpapillary RNFL thickness for localized and diffuse RNFL defects. Subgroup analysis was performed according to the severity of glaucoma. Results. For localized defects, the area of RNFL defects (AUC, 0.991; sensitivity, 97%; specificity, 90%) in deviation map showed a higher diagnostic performance (p = 0.002) than the best circumpapillary RNFL parameter (inferior RNFL thickness; AUC, 0.914; sensitivity, 79%; specificity, 92%). For diffuse defects, there was no significant difference between the RNFL deviation map and circumpapillary RNFL parameters. In mild glaucoma with localized defect, RNFL deviation map showed a better diagnostic performance than circumpapillary RNFL measurement. Conclusions. RNFL deviation map is a useful tool for evaluating glaucoma regardless of localized or diffuse defect type and has advantages over circumpapillary RNFL measurement for detecting localized RNFL defects.

Bus bays inventory using a terrestrial laser scanning system

This article presents the use of laser scanning technology for the assessment of bus bay geo-location. Ground laser scanning is an effective tool for collecting three-dimensional data. Moreover, the analysis of a point cloud dataset can be a source of a lot of information. The authors have outlined an innovative use of data collection and analysis using the TLS regarding information on the flatness of bus bays. The results were finalized in the form of colour three-dimensional maps of deviations and pavement type.

Geospatial analysis of census data for targeting new businesses using geoeconomics

Geoeconomics plays a vital role in encouraging goods and services on newmarketplaces. Selecting a “sweet-spot” for new businesses is one of the biggest challenges fornew entrepreneurs, enterprises, and investors, especially in the restaurant industry. This paperaims to present a novel geospatial methodological approach for new businesses using censusdata to answer an important business question: Where I should start my new Asian cuisinerestaurant? State and zip code tabulation area (ZCTA) level data on race and income,downloaded from the US census website, were applied for the analysis. ArcGIS software wasused as a geospatial analytics tool for hotspot analysis and for producing maps. Based on thestate level standard deviation map, California was found to have the second-highest relativeAsian population as gauged by the standard deviation (Std. Dev.) from the mean (1.5-2.5 Std.Dev.), after Hawaii (&gt;2.5 Std. Dev.), and followed by New Jersey, New York, Nevada, andWashington. The state of California was selected for further investigation. Seventeen of 58counties were found to be Asian community hotspots in California. A majority (48%, 854 of 1763)of the ZCTA were found to be Asian community hotspots in these zip codes in this state, andthis was statistically significant. Only 9% (163 of 1763) of the ZCTA were not statisticallysignificant Asian community hotspots, while 43% of the ZCTA were found to be statisticallysignificant coldspots of Asian communities in California. Among the 17 hotspot counties of Asiancommunities, 14 were also derived as hotspots of mean income. The road layer map revealedthat these ZCTAs are well connected to major roads in the state. New entrepreneurs,enterprises, and investors, those who are willing to open and or invest in new restaurants, butare not sure about the location, could target hotspot ZCTAs in these counties for Asian cuisine.Integrating ArcGIS with census data for producing maps of statistically significant potentialbusiness locations could be used as an important decision-making tool for opening newbusinesses.

Part Accuracy Management by Topological Mapping of Deviations

Despite modern manufacturing processes are characterized by a continuously increasing accuracy, geometric deviations inherently appear on every manufactured part so, for quality-aware companies, it is essential to control and to manage them. This paper introduces a new type of part geometrical model, namely the part topological map, in connection with a new approach in part accuracy management. The part topological map enables a global analytical &amp; synthetic approach of the problems related to tolerancing domain and a generalization of the “part accuracy” concept. The part geometry is seen as a stand-alone ensemble of surfaces dimensionally related, unitary and with its own shape, dimensions and position. The real geometry has also a global, unitary deviation, characterized through deviation features. Each component surface is represented in a particular manner, unrolled, while its deviation features are assessed by using series expansion of the deviations corresponding to a cloud of measured points. A method for effectively realizing the topological map of a part deviation and a numerical exercise to illustrate the method application in a concrete case are also included.

Prevalence of Split Nerve Fiber Layer Bundles in Healthy People Imaged with Spectral Domain Optical Coherence Tomography.

Objectives: The presence of retinal nerve fiber layer (RNFL) split bundles was recently described in normal eyes scanned using scanning laser polarimetry and by histologic studies. Split bundles may resemble RNFL loss in healthy eyes. The aim of our study was to determine the prevalence of nerve fiber layer split bundles in healthy people.Materials and Methods: We imaged 718 eyes of 359 healthy persons with the spectral domain optical coherence tomography in this cross-sectional study. All eyes had intraocular pressure of 21 mmHg or less, normal appearance of the optic nerve head, and normal visual fields (Humphrey Field Analyzer 24-2 full threshold program). In our study, a bundle was defined as ‘split’ when there is localized defect not resembling a wedge defect in the RNFL deviation map with a symmetrically divided RNFL appearance on the RNFL thickness map. The classification was performed by two independent observers who used an identical set of reference examples to standardize the classification.Results: Inter-observer consensus was reached in all cases. Bilateral superior split bundles were seen in 19 cases (5.29%) and unilateral superior split was observed in 15 cases (4.16%). In 325 cases (90.52%) there was no split bundle.Conclusion: Split nerve fiber layer bundles, in contrast to single nerve fiber layer bundles, are not common findings in healthy eyes. In eyes with normal optic disc appearance, especially when a superior RNFL defect is observed in RNFL deviation map, the RNLF thickness map and graphs should also be examined for split nerve fiber layer bundles.

Global Atmospheric Dynamics Investigated by Using Hilbert Frequency Analysis

The Hilbert transform is a well-known tool of time series analysis that has been widely used to investigate oscillatory signals that resemble a noisy periodic oscillation, because it allows instantaneous phase and frequency to be estimated, which in turn uncovers interesting properties of the underlying process that generates the signal. Here we use this tool to analyze atmospheric data: we consider daily-averaged Surface Air Temperature (SAT) time series recorded over a regular grid of locations covering the Earth’s surface. From each SAT time series, we calculate the instantaneous frequency time series by considering the Hilbert analytic signal. The properties of the obtained frequency data set are investigated by plotting the map of the average frequency and the map of the standard deviation of the frequency fluctuations. The average frequency map reveals well-defined large-scale structures: in the extra-tropics, the average frequency in general corresponds to the expected one-year period of solar forcing, while in the tropics, a different behaviour is found, with particular regions having a faster average frequency. In the standard deviation map, large-scale structures are also found, which tend to be located over regions of strong annual precipitation. Our results demonstrate that Hilbert analysis of SAT time-series uncovers meaningful information, and is therefore a promising tool for the study of other climatological variables.

Sexual Dimorphism of the Human Tibia through Time: Insights into Shape Variation Using a Surface-Based Approach.

In this paper we present a three-dimensional (3D) morphometrical assessment of human tibia sexual dimorphism based on whole bone digital representation. To detect shape–size and shape differences between sexes, we used geometric morphometric tools and colour-coded surface deviation maps. The surface-based methodology enabled analysis of sexually dimorphic features throughout the shaft and articular ends of the tibia. The overall study dataset consisted of 183 3D models of adult tibiae from three Czech population subsets, dating to the early medieval (9–10th century) (N = 65), early 20th century (N = 61) and 21st-century (N = 57). The time gap between the chronologically most distant and contemporary datasets was more than 1200 years. The results showed that, in all three datasets, sexual dimorphism was pronounced. There were some sex-dimorphic characteristics common to all three samples, such as tuberosity protrusion, anteriorly bowed shaft and relatively larger articular ends in males. Diachronic comparisons also revealed substantial shape variation related to the most dimorphic area. Male/female distinctions showed a consistent temporal trend regarding the location of dimorphic areas (shifting distally with time), while the maximal deviation between male and female digitized surfaces fluctuated and reached the lowest level in the 21st-century sample. Sex determination on a whole-surface basis yielded the lowest return of correct sex assignment in the 20th-century group, which represented the lowest socioeconomic status. The temporal variation could be attributed to changes in living conditions, the decreasing lower limb loading/labour division in the last 12 centuries having the greatest effect. Overall, the results showed that a surface-based approach is successful for analysing complex long bone geometry.

Chemical zoning and lattice distortion in uraninite from Olympic Dam, South Australia

Compositionally zoned uraninite from the Olympic Dam iron oxide-copper-gold deposit is rarely preserved, but represents an early product of in situ transformation of primary uraninite. Electron backscatter diffraction data (inverse pole figure, image quality, and grain reference orientation deviation mapping) reveal formation of zoned uraninite to be the result of a sequence of superimposed effects rather than from primary growth mechanisms alone. This is the first known microstructural analysis of uraninite showing crystal-plastic deformation of uraninite via formation and migration of defects and dislocations into tilt boundaries. Defining grain-scale characteristics and microstructural features in radiogenically modified minerals like uraninite carries implications in better understanding the processes involved in their formation, highlights limitations in the use of uraninite for U-Pb chemical ages, as well as for constraining the incorporation and release of daughter radioisotopes, especially where zoning, porosity, fractures, and microstructures are present.

PLANETARY CAUSTIC PERTURBATIONS OF A CLOSE-SEPARATION PLANET ON MICROLENSING

ABSTRACT Most planetary events discovered up to date by the planetary caustic of close-separation planets have low-mass ratios. In next-generation microlensing experiments with a wider field of view and a higher cadence, it is possible to obtain densely covered planetary signals induced by the planetary caustic of close-separation planets without missing events. Therefore, the planetary caustic perturbation of close-separation planets would be the more important channel to detect low-mass exoplanets in the next generation of microlensing surveys. In this paper, we investigate the theoretical properties and detection conditions for the planetary caustic perturbation of close-separation planets. To find the properties of the planetary caustic perturbation, we construct deviation maps by subtracting the single-lensing magnification of the lens star from the planetary lensing magnification for various lensing parameters. We find that each deviation area of the positive and negative perturbations disappears at the same normalized source radius according to a given deviation threshold regardless of mass ratio but disappears at a different normalized source radius according to the separation. We also estimate the upper limit of the normalized source radius to detect the planetary caustic perturbation. We find simple relations between the upper limit of the normalized source radius and the lensing parameters. From the relations, we obtain an analytic condition for the theoretical detection limit of the planet, which shows that we can sufficiently discover a planet with a sub-Earth-mass for typical microlensing events. Therefore, we conclude that our planet-detection condition of can be used as an important criteria for maximal planet detections, considering the source type and the photometric accuracy and expect that a number of low-mass planets will be added from the next-generation microlensing experiments.

3D Model Optimization of Four-Facet Drill for 3D Drilling Simulation

Abstract The article is focused on optimization of four-facet drill for 3D drilling numerical modelling. For optimization, the process of reverse engineering by PowerShape software was used. The design of four-facet drill was created in NumrotoPlus software. The modified 3D model of the drill was used in the numerical analysis of cutting forces. Verification of the accuracy of 3D models for reverse engineering was implemented using the colour deviation maps. The CAD model was in the STEP format. For simulation software, 3D model in the STEP format is ideal. STEP is a solid model. Simulation software automatically splits the 3D model into finite elements. The STEP model was therefore more suitable than the STL model.

Characteristics of Retinal Nerve Fiber Layer Defect in Nonglaucomatous Eyes With Type II Diabetes.

To investigate the characteristics of retinal nerve fiber layer (RNFL) defects associated with type II diabetes. Forty nonglaucomatous eyes with type II diabetes and 54 eyes with early open angle glaucoma that exhibited a localized RNFL defect and 42 eyes from age- and sex-matched nondiabetic, nonglaucomatous controls were imaged with red-free fundus photography and optical coherence tomography (Cirrus HD-OCT, Carl Zeiss Meditec). The area under the receiver operating characteristic curves of eyes with diabetes was compared with that of eyes with glaucoma. When an RNFL defect on fundus photographs was identified in the quadrant, clock-hour, temporal-superior-nasal-inferior-temporal (TSNIT), deviation, and thickness maps, it was considered a true detection. In eyes with diabetes, the RNFL defects were located more frequently in the superior hemisphere than they were in those with glaucoma (P < 0.001). The angular locations of RNFL defects in eyes with diabetes (56.1 ± 12.7°) were significantly farther from the fovea compared with those in glaucoma (44.3 ± 17.3°; P < 0.001); in addition, the width of RNFL defects in diabetes (5.1 ± 2.3°) was significantly narrower than those in glaucoma (20.8 ± 12.3°; P < 0.001). The best parameter discriminating RNFL defects in diabetes from those in glaucoma was width of RNFL defect (0.955), followed by rim area (0.844), and average RNFL (0.791). The thickness map showed a sensitivity (70%) and specificity (69.1%), superior to those of all other maps in eyes with diabetes. The narrow width and identification of RNFL defect in thickness map obtained with Cirrus HD-OCT seems to be an effective tool for detecting RNFL defects in diabetes.

Apport Des Images Satellites MODIS Dans L’étude De L’évolution De La Végétation Forestière De l’Est Algérien

The monitoring of forest dynamics is needed to better quantify the intensity of climate change and their impacted on forest resources of Algeria. The NDVI (Normalized Difference Vegetation Index) was often used to take this step. It is considered a fluctuating parameter in space and in time, very used today to measure the physiological activity of plants and characterize the vigor of vegetation. In this study we tried to characterize the one hand the spatial and temporal variability of NDVI of forest ecosystems of eastern Algeria and also spatially identify via statistical calculations the stressed forest parcels where chlorophyll activity leaves shows fluctuations and anomalies. The data used are those of the spectral index NDVI MODIS sensor for detecting photosynthetic signal returned by the tree canopy. It appears from this study that the vegetative activity of the forest ecosystems of eastern Algeria is always strong in the coastal massifs and decreases according to a latitudinal gradient oriented approximately North-South. In terms of the ecosystems, this activity is greater for deciduous stands than for softwoods. Moreover, the mapping of the standard deviation of NDVI allowed us, first, to spatially discriminate stressed forest parcels that are considered priorities for the establishment of effective conservation strategy and, secondly, to identify the most threatened tree species that requires a rapid response and collaboration between the institutions concerned to protect it.

Mapping dominant runoff processes: an evaluation of different approaches using similarity measures and synthetic runoff simulations

Abstract. The identification of landscapes with similar hydrological behaviour is useful for runoff and flood predictions in small ungauged catchments. An established method for landscape classification is based on the concept of dominant runoff process (DRP). The various DRP-mapping approaches differ with respect to the time and data required for mapping. Manual approaches based on expert knowledge are reliable but time-consuming, whereas automatic GIS-based approaches are easier to implement but rely on simplifications which restrict their application range. To what extent these simplifications are applicable in other catchments is unclear. More information is also needed on how the different complexities of automatic DRP-mapping approaches affect hydrological simulations. In this paper, three automatic approaches were used to map two catchments on the Swiss Plateau. The resulting maps were compared to reference maps obtained with manual mapping. Measures of agreement and association, a class comparison, and a deviation map were derived. The automatically derived DRP maps were used in synthetic runoff simulations with an adapted version of the PREVAH hydrological model, and simulation results compared with those from simulations using the reference maps. The DRP maps derived with the automatic approach with highest complexity and data requirement were the most similar to the reference maps, while those derived with simplified approaches without original soil information differed significantly in terms of both extent and distribution of the DRPs. The runoff simulations derived from the simpler DRP maps were more uncertain due to inaccuracies in the input data and their coarse resolution, but problems were also linked with the use of topography as a proxy for the storage capacity of soils. The perception of the intensity of the DRP classes also seems to vary among the different authors, and a standardised definition of DRPs is still lacking. Furthermore, we argue not to use expert knowledge for only model building and constraining, but also in the phase of landscape classification.

The use of close-range photogrammetry in zooarchaeology: Creating accurate 3D models of wolf crania to study dog domestication

Close-range photographic techniques - including photogrammetry - are becoming common tools for constructing three-dimensional (3D) models of artifacts, particularly in archaeological research. Whether models obtained through photogrammetry can be used for zooarchaeological studies requires a systematic examination. In the context of research into dog domestication, we explore whether 3D models of wolf crania, obtained through a photogrammetric approach, accurately describe the original cranium in term of colouration, texture and most importantly, geometry.To answer this question, we compared the topology of 3D models obtained with a high-resolution surface scanner (used as reference geometry) with models reconstructed from the same five wolf crania using photogrammetry. The pairs of models were then compared using both a visual, qualitative and two quantitative approaches. The latter, a geometric comparison computed the deviation map between the pairs of 3D models, which was then followed by a 3D landmark based geometric morphometric approach using corresponding analyses.Our results demonstrate that photogrammetry can produce 3D models with visually satisfying levels of morphological detail in terms of texture, colouration and geometry. In addition, the quantitative comparison of the models revealed an average distance between the two surfaces of 0.088mm with an average standard deviation of 0.53mm. The geometric morphometric analyses revealed the same degree of measurement error for the two series of scans (2.04% and 1.95%), with only 6.31% of the morphometric variation being due to the acquisition technique. Photogrammetry, therefore, offers a low cost, easily portable and simple to perform alternative to traditional surface scanning, affording advantages that make it a highly useful tool for zooarchaeological research.

Ganglion cell analysis at acute episode of nonarteritic anterior ischemic optic neuropathy to predict irreversible damage. A prospective study.

To assess the capability of ganglion cell-inner plexiform layer (GCIPL) thickness analysis by optical coherence tomography (OCT) to detect early neuronal loss in nonarteritic anterior ischemic optic neuropathy (NAION). Sixteen patients with unilateral NAION participated in this prospective study. Complete ophthalmologic evaluation including visual acuity, visual field (VF) test, and spectral domain optical coherence tomography (SD-OCT) of peripapillary retinal nerve fiber layer (pRNFL) and GCIPL thickness were performed in the acute phase (within 1week: 2.7 ± 2.1days) and at 2weeks, 1month, 3 and 6months after diagnosis. The mean time elapsed from acute episode to irreversible damage detection by GCIPL and pRNFL analysis was registered. Correlations between the GCIPL thinning and functional parameters such as best-corrected visual acuity (BCVA) and visual field indices [mean deviation (MD) and visual field index (VFI)] in acute and chronic phase were also analyzed. NAION eyes showed a significant thinning of the mean GCIPLminimum (min) compared to the unaffected eyes as early as 2.2days after symptoms onset (p = 0.017) and at each follow-up visit. (p ≤ 0.003). The mean GCIPL average (av) was also thinner in NAION eyes compared to uninvolved eyes at 1 (p = 0.003), 3 (p = 0.002) and 6months (p < 0.001). At the acute phase, 100% of NAION eyes showed significant pRNFL thickening, while abnormal thinning was evident in GCIPLav, GCIPLmin, and GCIPL deviation map analysis in 31.3, 56.3, and 62.5% of NAION eyes. The abnormal thinning rates increased to 43.8, 75, and 81.3% at 2weeks and to 62.5, 100, and 100% at 1month, respectively. At 2weeks, GCIPLmin thickness significantly correlated with both acute and chronic BCVA, MD, and VFI. Furthermore, the mean superior and inferior GCIPL thicknesses at 2weeks associated with corresponding mean inferior and superior hemifield MD at 6months. GCIPL analysis by SD-OCT can be considered as a useful biomarker to establish ganglion cell damage. GCIPL min and GCIPL deviation map are abnormally thinner in 56.3 % and 62.5 % of eyes at presentation, respectively. Therefore, both parameters are abnormally thinned in more than 50 % of eyes at presentation. At 2 weeks, GCIPL min thickness significantly correlated with chronic BCVA, MD and VFI; therefore, GCIPL min thickness can predict final visual dysfunction.

Accuracy of Intraoral Digital Impressions for Whole Upper Jaws, Including Full Dentitions and Palatal Soft Tissues.

Intraoral digital impressions have been stated to meet the clinical requirements for some teeth-supported restorations, though fewer evidences were proposed for larger scanning range. The aim of this study was to compare the accuracy (trueness and precision) of intraoral digital impressions for whole upper jaws, including the full dentitions and palatal soft tissues, as well as to determine the effect of different palatal vault height or arch width on accuracy of intraoral digital impressions. Thirty-two volunteers were divided into three groups according to the palatal vault height or arch width. Each volunteer received three scans with TRIOS intraoral scanner and one conventional impression of whole upper jaw. Three-dimensional (3D) images digitized from conventional gypsum casts by a laboratory scanner were chose as the reference models. All datasets were imported to a specific software program for 3D analysis by "best fit alignment" and "3D compare" process. Color-coded deviation maps showed qualitative visualization of the deviations. For the digital impressions for palatal soft tissues, trueness was (130.54±33.95)μm and precision was (55.26±11.21)μm. For the digital impressions for upper full dentitions, trueness was (80.01±17.78)μm and precision was (59.52±11.29)μm. Larger deviations were found between intraoral digital impressions and conventional impressions in the areas of palatal soft tissues than that in the areas of full dentitions (p<0.001). Precision of digital impressions for palatal soft tissues was slightly better than that for full dentitions (p = 0.049). There was no significant effect of palatal vault height on accuracy of digital impressions for palatal soft tissues (p>0.05), but arch width was found to have a significant effect on precision of intraoral digital impressions for full dentitions (p = 0.016). A linear correlation was found between arch width and precision of digital impressions for whole upper jaws (r = 0.326, p = 0.034 for palatal soft tissues and r = 0.485, p = 0.002 for full dentitions). It was feasible to use the intraoral scanner to obtain digital impressions for whole upper jaws. Wider dental arch contributed to lower precision of an intraoral digital impression. It should be confirmed in further studies that whether accuracy of digital impressions for whole upper jaws is clinically acceptable.

Maps of averaged spectral deviations from soil lines and their comparison with traditional soil maps

The analysis of 34 cloudless fragments of Landsat 5, 7, and 8 images (1985–2014) on the territory of Plavsk, Arsen’evsk, and Chern districts of Tula oblast has been performed. It is shown that bare soil surface on the RED–NIR plots derived from the images cannot be described in the form of a sector of spectral plane as it can be done for the NDVI values. The notion of spectral neighborhood of soil line (SNSL) is suggested. It is defined as the sum of points of the RED–NIR spectral space, which are characterized by spectral characteristics of the bare soil applied for constructing soil lines. The way of the SNSL separation along the line of the lowest concentration density of points on the RED–NIR spectral space is suggested. This line separates bare soil surface from vegetating plants. The SNSL has been applied to construct soil line (SL) for each of the 34 images and to delineate bare soil surface on them. Distances from the points with averaged RED–NIR coordinates to the SL have been calculated using the method of moving window. These distances can be referred to as averaged spectral deviations (ASDs). The calculations have been performed strictly for the SNSL areas. As a result, 34 maps of ASDs have been created. These maps contain ASD values for 6036 points of a grid used in the study. Then, the integral map of normalized ASD values has been built with due account for the number of points participating in the calculation (i.e., lying in the SNSL) within the moving window. The integral map of ASD values has been compared with four traditional soil maps on the studied territory. It is shown that this integral map can be interpreted in terms of soil taxa: the areas of seven soil subtypes (soddy moderately podzolic, soddy slightly podzolic, light gray forest. gray forest, dark gray forest, podzolized chernozems, and leached chernozems) belonging to three soil types (soddy-podzolic, gray forest, and chernozemic soils) can be delineated on it.

Linking land subsidence over the Yellow River delta, China, to hydrocarbon exploitation using multi-temporal InSAR

The Yellow River delta, the second largest oil and gas base of China, has been subsiding due to the combination effects of human and natural factors. Increasing anthropogenic activities, like hydrocarbon exploitation, accelerate the subsidence, gradually threatening the stability of infrastructures and causing the inhabitants more vulnerable to natural hazards. Interferometric synthetic aperture radar (InSAR) techniques can measure ground movements in high resolution. The purpose of this study is to map the spatial and temporal variations in surface deformation over the Yellow River delta using a Small Baseline Subset InSAR technique and to assess the role of hydrocarbon exploitation in subsidence. The Stanford Method for Persistent Scatterers/Multi-Temporal InSAR (StaMPS/MTI) package is employed to process ENVISAT ASAR images collected from 2007 to 2010. InSAR-derived surface deformation measurements are then compared to geological and petroleum geologic data, oil field data and hydrocarbon reservoir inversion information to address the causes of the observed subsidence. Spirit leveling data and standard deviation maps are used to verify the InSAR results and measurement accuracy. Consistent results of the two descending tracks indicate subsidence up to 40 mm/yr over oil field. The time-series deformation manifests that subsidence area and peak broaden over time and subsidence rate are approximately constant in Shikou oil field, while the rate decreases in Dongying oil field since 2009. Moreover, our results indicate that the land subsidence pattern is concentrated in hydrocarbon exploration field and has a good consistency with faults distributions. In addition, a multiple finite prolate ellipsoid sources model is implemented to model the InSAR-derived deformation in Shikou oil field. The model manifests that land subsidence and hydrocarbon exploitation can be quantitatively linked to each other. The intimate connection of surface deformation with reservoir change suggests that land subsidence over oil field in the Yellow River delta is primarily caused by hydrocarbon exploitation. The results provide new insights into the land subsidence mechanism in the Yellow River delta.

Acute ganglion cell loss during rapid visual recovery in optic neuritis.

To report dynamic changes in the retinal ganglion cell layer (GCL) and visual function in acute and chronic optic neuritis (ON). Sixteen eyes (15 patients) with acute ON were followed for 3.5 to 31months (average, 10.2). The best-corrected visual acuity (BCVA) and thickness of the GCL plus the inner plexiform layer (GCL+IPL) were measured 4 to 13 times between baseline and the final visit using the ganglion cell analysis software in the Cirrus HD-OCT [high-definition optical coherence tomography] instrument. Goldmann perimetry was performed at baseline and at the final visit. The thickness of the GCL+IPL at baseline was within normal limits in the affected (80.4 ± 4.9 microns) and unaffected fellow eyes (80.5 ± 5.0 microns). Rapid thinning to 69 ± 7.3 microns occurred during month 1 in the affected eyes, slowing during month 2, and then reaching a minimum level (63.6 ± 8.7 microns). In contrast, BCVA was lowest (mean ± standard deviation logarithm of the minimum angle of resolution, -1.29 ± 0.96) in 11 eyes at baseline, increased markedly to -0.15 ± 0.37 during month 1, and reached a maximum level (-0.18 ± 0.19) during month 2 and (-0.02 ± 0.23) at the final visit. The BCVA in the other five eyes fluctuated during month 1, increased markedly during month 2, and then reached a maximum plateau (-0.07 ± 0.20). The patterns of visual field defects at baseline were varied, and were determinants of BCVA. The visual field largely recovered in 11 eyes, but small central scotomas in four eyes and an enlarged blind spot in one eye remained at the final visit. Eyes with the least GCL+IPL thinning at month 1 or 2 had the least depression in the final deviation map. In acute ON, the progression toward irreversible ganglion cell loss occurs rapidly during months 1 and 2. In contrast, visual function recovers rapidly during the same period. Remodeling of the neural network may occur between the photoreceptors and the reduced numbers of ganglion cells during the first months of ON. The small number of residual ganglion cells appears to compensate for the initial visual dysfunction.