Background Layer Research Articles

Codeposited pentacene:perfluoropentacene grown on SiO2: A microstructural study by transmission electron microscopy

The structure and morphology of codeposited pentacene (PEN, C22H14) and perfluoropentacene (PFP, C22F14) grown with mixing ratios of [2:1], [1.1] and [1:2] on SiO2 substrates were investigated by means of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. Electron diffraction experiments showed the presence of a mixed phase consisting of PEN and PFP with similar lattice parameters for all samples. The electron diffraction pattern of the mixed phase exhibits a rather similar symmetry as the one of pure PEN in [001] orientation. This suggests that the crystalline structure of the mixed phase and of pure PEN should be very similar. However, the lattice spacing of the mixed phase is slightly larger in some directions than the one of pure PEN. SEM, scanning TEM (STEM) and dark field imaging reveal a change in morphology for different PEN:PFP mixing ratios during growth. In the case of PFP excess, PFP fibers on a background layer formed by the mixed phase are observed. The equimolecular mixture of PEN and PFP exhibits a structure consisting of fiber-like structures. With excess of PEN a grainy structure with contributions of pure PEN and of the mixed phase is found with a grain size in the range of (10−60) nm.

Screen Content Image Segmentation Using Robust Regression and Sparse Decomposition

This paper considers how to separate text and/or graphics from smooth background in screen content and mixed document images and proposes two approaches to perform this segmentation task. The proposed methods make use of the fact that the background in each block is usually smoothly varying and can be modeled well by a linear combination of a few smoothly varying basis functions, while the foreground text and graphics create sharp discontinuity. The algorithms separate the background and foreground pixels by trying to fit background pixel values in the block into a smooth function using two different schemes. One is based on robust regression, where the inlier pixels will be considered as background, while remaining outlier pixels will be considered foreground. The second approach uses a sparse decomposition framework where the background and foreground layers are modeled with a smooth and sparse components respectively. These algorithms have been tested on images extracted from HEVC standard test sequences for screen content coding, and are shown to have superior performance over previous approaches. The proposed methods can be used in different applications such as text extraction, separate coding of background and foreground for compression of screen content, and medical image segmentation.

A hierarchical polymer brush coating with dual-function antibacterial capability

Bacterial infections are problematic in many healthcare-associated devices. Antibacterial surfaces integrating the strength of bacteria repellent and bactericidal functions exhibit an encouraging efficacy in tackling this problem. Herein, a hierarchical dual-function antibacterial polymer brush coating that integrates an antifouling bottom layer with a bactericidal top layer is facilely constructed via living photograft polymerization. Excellent resistance to bacterial attachment is correlated with the antifouling components, and good bactericidal activity is afforded by the bactericidal components, and therefore the hierarchical coating shows an excellent long-term antibacterial capability. In addition, due to the presence of the hydrophilic background layer, the hierarchical surface has the greatly improved biocompatibility, as shown by the suppression of platelet adhesion and activation, the inhibition of erythrocyte adhesion and damage, and low toxicity against mammalian cells. The hierarchical polymer brush system provides the basis for the development of long-term antibacterial and biocompatible surfaces.

A hierarchical polymer brush coating with dual-function antibacterial capability

Bacterial infections are problematic in many healthcare-associated devices. Antibacterial surfaces integrating the strength of bacteria repellent and bactericidal functions exhibit an encouraging efficacy in tackling this problem. Herein, a hierarchical dual-function antibacterial polymer brush coating that integrates an antifouling bottom layer with a bactericidal top layer is facilely constructed via living photograft polymerization. Excellent resistance to bacterial attachment is correlated with the antifouling components, and good bactericidal activity is afforded by the bactericidal components, and therefore the hierarchical coating shows an excellent long-term antibacterial capability. In addition, due to the presence of the hydrophilic background layer, the hierarchical surface has the greatly improved biocompatibility, as shown by the suppression of platelet adhesion and activation, the inhibition of erythrocyte adhesion and damage, and low toxicity against mammalian cells. The hierarchical polymer brush system provides the basis for the development of long-term antibacterial and biocompatible surfaces.

Improved TV Algorithm Based on Adaptive Multiplier for Interference Hyperspectral Image Decomposition

Interference Hyperspectral Images (IHI) data acquired by Interference Hyperspectral Imaging Spectrometer exhibit many vertical interference stripes. The above characteristics will affect the application of dictionary learning and compressed sensing theory used on IHI data. According to the special characteristics of IHI data, many algorithms are proposed to separate the interference stripes layers and the background layers of IHI data in 2015, but the interference stripes layers are still not clean enough and the ideal background layers without interference stripes are also difficult to be obtained. In this paper, an improved total variation (TV) algorithm based on adaptive multiplier is proposed for IHI data decomposition. The value of the Lagrange multiplier is adaptive according to the unidirectional characteristics of IHI data. The proposed algorithm is used on Large Spatially Modulated Interference Spectral (LSMIS) images and is proved to provide better experimental results than the current algorithms both visually and quantitatively.

The Modality of Artistic Objects

Nicolai Hartmann describes how artistic objects arise through the interplay between a material foreground and immaterial background. In this paper, I show how the layered structure also prevents the modal imbalance inherent in artistic objects from violating the intermodal laws of the real. The real law of intermodal implication specifies that real possibility cannot extend beyond real necessity. I begin by explicating the real intermodal laws and describing how they give the real sphere its characteristic narrowness and determinateness. Hartmann describes artistic objects as entailing a possibility that extends beyond real necessity. This intermodal imbalance does not, however, threaten the hegemony of the real intermodal laws, because only its foreground layer is fully situated within the real sphere of being. Its background layer has components that belong to the ideal sphere governed by the ideal modes. For the ideal modes, the law of intermodal implication only holds in one direction so that what is necessary must be actual and what is actual must be possible. Since this relation of implication is not reciprocal for the ideal modes, ideal possibility implies neither ideal actuality nor ideal necessity.

Parameter‐adaptive nighttime image enhancement with multi‐scale decomposition

As a challenging problem, image enhancement plays an important role in computer vision applications and has been widely studied. As one of the most difficult issues of image enhancement, outdoor nighttime image enhancement suffers from noise amplification easily. To solve this problem, this study proposes a parameter‐adaptive nighttime image enhancement method with multi‐scale decomposition. The main contributions of this work are threefold. First, the authors find out that noises in different scales are various, and their method decomposes an input image into three high‐frequency layers and a background layer accordingly. Second, the authors’ method enhances each high‐frequency layer using adaptive parameters based on the characteristics of noises. Third, the proposed method maps the background layer to make it suitable to present details. Experiment results demonstrate that the proposed method can suppress noises as well as improve details effectively.

Hierarchical Polymer Brushes with Dominant Antibacterial Mechanisms Switching from Bactericidal to Bacteria Repellent.

Although polycationic surfaces have high antimicrobial efficacies, they suffer from high toxicity to mammalian cells and severe surface accumulation of dead bacteria. For the first time, we propose a surface-initiated photoiniferter-mediated polymerization (SI-PIMP) strategy of constructing a "cleaning" zwitterionic outer layer on a polycationic bactericidal background layer to physically hinder the availability of polycationic moieties for mammalian cells in aqueous service. In dry conditions, the polycationic layer exerts the contact-active bactericidal property toward the adherent bacteria, as the zwitterionic layer collapses. In aqueous environment, the zwitterionic layer forms a hydration layer to significantly inhibit the attachment of planktonic bacteria and the accumulation of dead bacteria, while the polycationic layer kills bacteria occasionally deposited on the surface, thus preserving the antibacterial capability for a long period. More importantly, the zwitterionic hydrated layer protects the mammalian cells from toxicity induced by the bactericidal background layer, and therefore hierarchical antibacterial surfaces present much better biocompatibility than that of the naked cationic references. The dominant antibacterial mechanism of the hierarchical surfaces can switch from the bactericidal efficacy in dry storage to the bacteria repellent capability in aqueous service, showing great advantages in the infection-resistant applications.

A Background Layer in Aesthetic Experience: Cross‐cultural Affective Symbolism

This study explored the role of affective/physiognomic perception in emotion perception, and its contribution to meaning construction in the absence of any representation. Following Werner's microgenetic paradigm, by peeling away the fossilized representational level in the drawings, we attempted to link both the “subjective” emotion experience of the artists, articulated in line‐drawings that functioned as the spectators’ perceptual stimulus. Subsequently, a cross‐cultural study was performed using 12 non‐representational, emotion drawings as experimental stimuli of the emotion at hand, to investigate any correspondence of feeling between spectators (152 Canadian, 48 Greek, and 72 Japanese participants) and emotions expressed in the drawings. The results suggested a relative congruence of feeling reflected in the gross classification of the stimuli, and coordination in the organization of perceived affect across cultures. Mood‐state and mood‐trait played differential roles in recognition accuracy. Greeks showed impaired classification for negative drawings, not modifying internal structures accordingly to external constraints, and being oversensitive to subjective arousal in the aversive ambiguous stimuli. Japanese coped with aversion in an implicit aesthetic manner, being task oriented while not flattening the experiential impact of the stimuli. Canadians were not insensitive to body cues, but their impact was overridden by the salience of the attended object.

Application of plume analysis to build land use regression models from mobile sampling to improve model transferability

Mobile monitoring of traffic-related air pollutants was conducted in Pittsburgh, PA. The data show substantial spatial variability of particle-bound polycyclic aromatic hydrocarbons (PB-PAH) and black carbon (BC). This variability is driven in large part by pollutant plumes from high emitting vehicles (HEVs). These plumes contribute a disproportionately large fraction of the near-road exposures of PB-PAH and BC. We developed novel statistical models to describe the spatial patterns of PB-PAH and BC exposures. The models consist of two layers: a plume layer to describe the contributions of high emitting vehicles using a near-roadway kernel, and an urban-background layer that predicts the spatial pattern of other sources using land use regression. This approach leverages unique information content of highly time resolved mobile monitoring data and provides insight into source contributions. The two-layer model describes 76% of observed PB-PAH variation and 61% of BC variation. On average, HEVs contribute at least 32% of outdoor PB-PAH and 14% of BC. The transferability of the models was examined using measurements from 36 hold-out validation sites. The plume layer performed well at validation sites, but the background layer showed little transferability due to the large difference in land use between the city and outer suburbs.

Inorganic fouling of an anaerobic membrane bioreactor treating leachate from the organic fraction of municipal solid waste (OFMSW) and a polishing aerobic membrane bioreactor

The treatment of leachate (Average TCOD=11.97g/L, 14.4% soluble) from the organic fraction of municipal solid waste was investigated using a Submerged Anaerobic Membrane BioReactor (SAMBR), followed by an aerobic membrane bioreactor (AMBR) to polish this effluent. This paper investigated the exact nature and composition of the inorganic precipitate in each of the reactors in the process. The flux decreased due to precipitation of calcium as monohydrocalcite (CaCO3·H2O) containing traces of metals onto the SAMBR membrane because of high CO2 partial pressures. Precipitation of calcium in the AMBR was also observed due to a higher pH. In this case, phosphorus also precipitated with calcium in two different phases: the background layer contained calcium, oxygen, carbon and small amounts of phosphorus (2–6.7%), while flakes containing calcium, oxygen and higher amounts of phosphorus (10–17%) were probably hydroxyapatite (Ca5(PO4)3OH).

Kirchhoff prestack migration using the suppressed wave equation estimation of traveltime (SWEET) algorithm in VTI media

This paper examines anisotropic prestack Kirchhoff migration. We used pseudo-acoustic wave equations in the complex frequency domain to describe the wave propagation in a vertical transversely isotropic (VTI) medium. Both amplitudes and traveltimes were calculated efficiently using the suppressed wave equation estimation of traveltime (SWEET) algorithm. The accuracy of the traveltimes obtained with the SWEET algorithm was verified by comparing the traveltime contours simulated with the anisotropic elastic wave equation using a staggered-grid method. Finally, we tested our migration algorithm using the two-dimensional HESS VTI model. We correctly imaged the shape of both the salt and background layer structures. We also reduced the numerical artefacts compared to the isotropic technique.

Self-Assembled Nanoparticle Arrays on Chemical Nanopatterns Prepared Using Block Copolymer Lithography.

We present a high-throughput and inexpensive fabrication approach that uses self-assembled block copolymer (BCP) films as templates to generate dense nanoscale chemical patterns of polymer brushes for the selective immobilization of Au nanoparticles (NPs). A cross-linked random copolymer mat that contains styrene and methyl methacrylate units serves both as a base layer for perpendicular assembly of nanoscale domains of poly(styrene-block-methyl methacrylate) (PS-b-PMMA) films and as a nonadsorbing background layer that surrounds the chemical patterns. The selective removal of the PMMA block and the underlying mat via oxygen plasma etching generates binding sites which are then functionalized with poly(2-vinylpyridine) (P2VP) brushes. Au NPs with a diameter of 13 nm selectively immobilize on the patterned P2VP brushes. An essential aspect in fabricating high quality chemical patterns is the superior behavior of methyl methacrylate containing cross-linked mats in retaining their chemistry during the grafting of P2VP brushes. The use of BCPs with different molecular weights and volume fractions allows for preparation of chemical patterns with different geometries, sizes, and pitches for generating arrays of single particles that hold great promise for applications that range from molecular sensing to optical devices.

Usability in 4D AR: Visualising Multi-temporal Real-time Geo-data in Augmented Reality Environments

Even though advantages of 3D visualisation of multi-temporal geo-data versus 2D approaches have been widely proven, the particular pertaining challenge of real-time visualisation of geo-data in mobile Digital Earth applications has not been thoroughly tackled so far. In the emerging field of Augmented Reality (AR), research needs comprise finding the optimal information density, the interplay between orientation data in the background and other information layers, using the appropriate graphical variables for display, or selecting real-time base data with adequate quality and suitable spatial accuracy. In this paper we present a concept for integrating real-time data into 4D (three spatial dimensions plus time) AR environments, i.e., data with “high” spatial and temporal variations. We focus on three research challenges: 1.) high-performance integration of real-time data into AR; 2.) usability design in terms of displaying spatio-temporal developments and the interaction with the application; and 3.) design considerations regarding reality vs. virtuality, visualisation complexity and information density. We validated our approach in a prototypical application and extracted several limitations and future research areas including natural feature recognition, the cross-connection of (oftentimes monolithic) AR interface developments and well-established cartographic principles, or fostering the understanding of the temporal context in dynamic 4D Augmented Reality environments.

Optimization of Background Information and Layer Thickness for Improved Accuracy of Water-Vapor Profile Retrieval from Ground-Based Microwave Radiometer Measurements at K-Band

Ground-based microwave radiometers operating at frequencies near the 22.235 GHz (K-band) water vapor absorption line have been used extensively for remote sensing of water vapor in the troposphere, both the integrated amount and its profile. This paper explores the potential to use ground-based, zenith-pointing K-band radiometer measurements along with optimized background data sets consisting of radiosonde profiles to detect dynamic changes and gradients in water vapor profiles. To explore this capability, the HUMidity EXperiment 2011 (HUMEX11) was conducted at the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Site near Lamont, OK, USA. This enables the choice of appropriate retrieval parameters to monitor temporal changes in atmospheric water vapor profiles. The results of this study illustrate that in a retrieval algorithm both the choice of the size of the background data set measured near the radiometer measurement time and the choice of atmospheric layer thickness affect the ability to remotely sense dynamic changes in water vapor. In general, it is found that background data sets of larger size provide better accuracy in a statistical sense but inhibit the ability to detect gradients.

Convective boundary layer evolution from lidar backscatter and its relationship with surface aerosol concentration at a location of a central China megacity

AbstractBased on the 1 min backscatter ratio R profiles from the all‐day lidar measurements in Wuhan, China (30.5°N, 114.4°E), hourly convective boundary layer (CBL) height was calculated with the variance method. The calculated CBL height sequence displays the regular diurnal cycle of the CBL top. The prevalent mixing process within the CBL is also revealed. During the CBL growth period, the backscatter ratio R falls visibly with increasing altitude and has large variance within the CBL, suggesting that more abundant aerosol particles from lower altitudes are being transported upward and being mixed with the local background or advected aerosol layers. During the CBL quasistationary period, R tends to be vertically uniform, and its variance reaches a daytime minimum within the CBL, indicating that the vertical homogenization of aerosol particles produced by the convectively driven mixing reaches its maximum. During the afternoon and early evening transition period, the vertical uniformity of R weakens and the variance enlarges again, implying that the reduced convectively driven mixing fails to maintain a high vertical homogeneity. When the 1 min R profiles were plotted together in terms of each 1 h interval, the fluctuating R curves at heights around the CBL top looked like a “node”, representing the structure of the entrainment zone between the CBL and the free troposphere. The moving node depicts the evolution of the entrainment zone. The diurnal variation of the CBL height shows an obvious seasonal dependence which coincides with the annual variation of the local surface temperature. The surface fine particle concentration generally has a more complex diurnal cycle than that expected from the CBL‐dilution/CBL‐accumulation effect. But, it shows a strong annual variation which is out of phase with respect to that of the monthly mean maximum CBL height. This tends to suggest that the seasonal behavior of the surface fine particle concentration mainly depends on the seasonal variation in available volume (determined by the CBL height) for aerosol dispersion.

Improved morphological component analysis for interference hyperspectral image decomposition

Due to the special imaging principle, lots of vertical interference stripes exist in the frames of the IHI (interference hyperspectral image) data, which will affect the result of compressed sensing theory or other traditional compression algorithms used on IHI data. In this paper, MCA (morphological component analysis) algorithm is adopted to separate the interference stripes layers and the background layers, and an IMCA (improved MCA) algorithm is proposed according to the characteristics of the IHI data, dictionary learned from the LSMIS (Large Spatially Modulated Interference Spectral Image) data is used to sparsely represent the stripes layers instead of traditional basis, and the condition of iteration convergence is improved. The experimental results prove that the proposed IMCA algorithm can get better results than the traditional MCA, and also can meet the convergence conditions much faster than the traditional MCA.

Improved MCA–TV algorithm for interference hyperspectral image decomposition

The technology of interference hyperspectral imaging, which can get the spectral and spatial information of the observed targets, is a very powerful technology in the field of remote sensing. Due to the special imaging principle, there are many position-fixed interference fringes in each frame of the interference hyperspectral image (IHI) data. This characteristic will affect the result of compressed sensing theory and traditional compression algorithms used on IHI data. According to this characteristic of the IHI data, morphological component analysis (MCA) is adopted to separate the interference fringes layers and the background layers of the LSMIS (Large Spatially Modulated Interference Spectral Image) data, and an improved MCA and Total Variation (TV) combined algorithm is proposed in this paper. An update mode of the threshold in traditional MCA is proposed, and the traditional TV algorithm is also improved according to the unidirectional characteristic of the interference fringes in IHI data. The experimental results prove that the proposed improved MCA–TV (IMT) algorithm can get better results than the traditional MCA, and also can meet the convergence conditions much faster than the traditional MCA.

Depths, migration rates and environmental associations of acoustic scattering layers in the Gulf of California

The ecology in the Gulf of California has undergone dramatic changes over the past century, including the emergence of Humboldt squid (Dosidicus gigas) as a dominant predator. In the face of these changes, we compare the ubiquitous and ecologically important concentrations of mid-water organisms that comprise acoustic scattering layers to published results, describing their occurrence in detail and showing that they remain similar to features described 50 years previously. To classify scattering layers in the region, we applied an automatic detection algorithm to shipboard echosounder data from four cruises. We consistently detected a broad (>200m) background layer with a mean daytime bottom boundary depth of 463±56m (night: 434±66m), a near-surface layer with mean daytime bottom depth of 43±40m (night: 61±38m), and a main migrating layer with mean bottom depth of 333±76m (night: 54±27m). Diel vertical migration rates for dusk ascents reached a maximum, on average, of 8.6±3.1cms−1, and dawn descents averaged a maximum of 6.9±2.4cms−1. Deep scattering layers were often found concurrent with regions of severe hypoxia and we used environmental data to test for the association of scattering layer boundaries with environmental parameter values. Although results were inconsistent, we found scattering layer depths to be more highly associated with temperature and density than with oxygen. These results suggest that the recent success of D. gigas in the Gulf of California is not likely to be attributable to the effects of shoaling oxygen minimum zones on acoustic scattering layers.

MRC 기반의 영상 부호화를 위한 분수령 알고리즘을 이용한 효과적인 신호 채움 기법

Mixed raster content 모델 기반의 영상 부호화는 전경과 배경 레이어에 빈 영역인 don't care region (DCR)이 발생하게 되며, 이 영역에 대한 신호 채움 방식에 따라 전체적인 부호화 성능이 큰 영향을 받게 된다. DCR을 채우기 위한 대부분의 기존 기법들은 홀 주변 기존 영역의 특성을 효율적으로 이용하지 않아 신호 채움 후에도 기존 신호 영역에 존재하던 고주파 성분이 반영될 뿐 아니라, DCR 경계에서의 신호 불연속으로 인해 고주파 성분이 추가적으로 발생한다는 문제점을 갖고 있다. 이 문제를 해결하기 위해 본 논문은 우선순위 기반의 적응적 영역 확장법을 이용한 새로운 DCR 채움 알고리즘을 제안한다. 제안 알고리즘은 분수령 알고리즘을 이용하여 DCR의 각 홀 픽셀에 대한 신호 특성을 판단한 후, 이를 토대로 영역 채움의 우선순위를 결정한다. 이 우선 순위를 기반으로 영역 확장을 수행함으로써 고주파 성분을 포함하고 있는 영역의 확장이 최소화되어 전체적인 부호화 효율이 향상될 수 있다. 실험 결과를 통해 제안 알고리즘이 비교 대상 알고리즘에 비해 효율적인 신호 채움으로 우수한 부호화 성능을 가짐을 보인다. Image coding based on mixed raster content model generates don't care regions (DCR) in foreground and background layers, and its overall coding performance is greatly affected by region filling methods for DCRs. Most conventional methods for DCR filling fail in utilizing the local signal properties in hole regions and thus the high frequency components in non-DCR regions are reflected into DCR after signal filling. In addition, further high frequency components are induced to the filled signal because of signal discontinuities in the boundary of DCR. To solve this problem, a new DCR filling algorithm using the priority-based adaptive region growing is proposed in this paper. The proposed method uses the watershed algorithm and the flooding priority of each pixel for region filling is determined from the degree of smoothness in the neighborhood area. By growing the filled region into DCR based on the computed priority, the expansion of high-textured area can be minimized which can improve the overall coding performance. Experimental results show that the proposed method outperforms conventional algorithms.