Pattern Edge Research Articles

Evaluation of cellular plasticity in the collecting duct during recovery from lithium-induced nephrogenic diabetes insipidus

The cellular morphology of the collecting duct is altered by chronic lithium treatment. We have previously shown that lithium increases the fraction of type-A intercalated cells and lowers the fraction of principal cells along the collecting duct. Moreover, type-A intercalated cells acquire a long-row distribution pattern along the tubules. In the present study, we show that these morphological changes reverse progressively after discontinuation of lithium and finally disappear after 19 days from lithium suspension. In this time frame we have identified for the first time, in vivo, a novel cellular type positive for both intercalated and principal cells functional markers, as recognized by colabeling with H(+)-ATPase/aquaporin-4 (AQP4) and anion exchanger-1 (AE-1)/AQP2 and Foxi1/AQP4. This cell type is mainly present after 6 days of lithium washout, and it disappears in parallel with the long-row pattern of the type-A intercalated cells. It usually localizes either in the middle or at the edge of the long-row pattern. Its ultrastructure resembles the intercalated cells as shown both by differential interference contrast and by electron microscopy. The time course of appearance, the localization along the collecting duct, and the ultrastructure suggest that the cells double labeled for principal and intercalated cells markers could represent a transition element driving the conversion of intercalated cells into principal cells.

The influence of network structure on neuronal dynamics

Understanding the influence of network structure on neural dynamics is a fundamental step toward deciphering brain function, yet presents many challenges. We show how networks may be described in terms of the occurrences of certain patterns of edges, and how the frequency of these motifs (see Figure ​Figure1)1) impacts global dynamics. Through analysis and simulation of neuronal networks, we have found that two edge directed paths (two-chains) have the most dramatic effect on dynamics. Our analytic results are based on equations for mean population activity and correlations that we derive using path integrals and moment hierarchy expansions. These equations reveal the primary ways in which the network motifs influence dynamics. For example, the equations indicate that the propensity of a network to globally synchronize increases with the prevalence of two-chains, and we verify this result with network simulations. Finally, we present ongoing work investigating when these second-order equations break down, and how they might be corrected by higher order approximations to the network structure, such as the prevalence of three edge chains beyond that predicted by the two-chains. Figure 1 The four second order edge motifs of reciprocal, convergent, divergent, and causal connections. The frequency of these motifs determine the second order statistics, or correlations, among the network connections.

Controlled buckling behavior of patterned oxide structures on compliant substrates for flexible optoelectronics

There is currently a great interest to design and fabricate novel flexible devices for solar cell, solid-state lighting, biomedical and energy harvesting applications. Such devices require the use of electrode components. Desired electrodes must exhibit structural integrity, low electrical resistivity and, in most cases, high optical transparency in the visible range.Despite growing efforts to replace them, transparent conducting oxide layers deposited on polymer substrates are still enjoying a dominant role as the electrode component. This is because of their excellent combination of electrical and optical properties. However, their performance when they are subjected to externally-applied mechanical stresses is limited. Such performance has been extensively investigated for the case of continuous brittle oxide films on polymer substrates. However, there is relatively little work reported to date on the mechanical behavior of patterned conducting layers on compliant substrates.In this study we report on the mechanical behavior of various patterned indium tin oxide shapes and sizes on polyethylene terephthalate. Micron-sized shapes include squares, circles, and zigzag-based structures. Controlled buckling experiments are performed in-situ using an optical microscope in order to monitor critical strains and potential failure mechanisms. In addition, ITO electrical resistance changes are continuously monitored during deformation. Furthermore, ex-situ characterization of the tested surfaces using scanning electron microscopy is conducted. Higher crack onset values are observed for the smaller size patterns. Also, square-shaped patterns are found to exhibit the lowest crack onset values. SEM observations suggest cracking-driven and buckling-driven delamination during ITO tensile and compressive buckling mode respectively. In both cases, failure is observed to initiate from the pattern edges.

Microstructural analysis of InGaN/GaN epitaxial layers of metal organic chemical vapor deposition on c-plane of convex patterned sapphire substrate

The microstructures of the P-GaN (250nm)/GaN cap (~35nm)/7 pairs of InGaN/GaN MQWs (multi-quantum wells)/n-GaN (3 μm)/HT (high temperature)-GaN (3 μm)/LT (low temperature)-GaN buffer (5nm) on c-plane convex patterned sapphire substrate were analyzed using transmission electron microscopy (TEM). High density of dislocations in the LT-GaN buffer layer at both flat and convex patterned regions was observed to form. At the flat region, some of high dislocations formed at LT-GaN buffer grew over, bended to from stair-like dislocations extended along the edge of the convex pattern and then transformed to TDs (threading dislocations) extending through the InGaN/GaN epitaxial layers. However, few TDs reached the top of the epitaxial layers. Quantitative analysis revealed that the dislocation density has been drastically reduced to ~106 cm−2, reducing formation of V-defects at the 7 pairs of multi-quantum-wells near the surface.

Inclusional association as studied by the drying dissipative structure. Part 2. Drying pattern of n-alkyltrimethylammonium bromide

Macro- and microscopic drying patterns were observed on a cover glass and a watch glass during the course of dryness of aqueous solutions of a series of n-alkyltrimethylammonium bromides (alkyl: n-decyl, n-dodecyl, n-tetradecyl, and n-hexadecyl). The broad rings formed at the outside edges of the macroscopic patterns. Size of the initial liquid on the substrates, d i, that of the final broad ring, d f, and the ratio, d f/d i, changed as the surfactant concentration changed, and there appeared a bending point in each curve, which was found to correspond to the critical micelle concentration (cmc) of the surfactant. The cmc values evaluated from the d i, d f, and d f/d i values agreed well with the reference values reported previously. Cooperative drying processes of the convection, sedimentation, and solidification were supported. Microscopic drying patterns such as rod-like, dendritic, and granule-like patterns were observed, and they changed as a function of the carbon number of the alkyl groups, surfactant concentration, and the distance from the center of the pattern.

Si-Passivation of Epitaxial SiGe: Kinetics and Impact on Morphology

In this work a process was developed to passivate epitaxial SiGe on Si (001) substrates by a very thin Si layer. The Si-passivation was characterized in terms of deposition kinetics and of impact on the SiGe morphology during annealing. Different passivation durations allowed determining the time-dependence of the deposited thickness. A non-linear behavior was found resulting in a non-constant growth rate which decreases rapidly during the first seconds of passivation. Concerning the morphology of annealed SiGe, we showed that it can be strongly influenced by Si-passivation. The undulations appearing due to strain relaxation decrease in amplitude with increasing passivation duration until disappearance. In contrast, the morphology observed at the pattern edge, caused by thermal rounding, was not stabilized with similar passivation and annealing conditions.

English

The ultimate goal of agricultural spraying application system is to put the correct amount of pesticides, in the correct place, at the correct time to reduce the pest to a level below the economic threshold in order to improve agricultural production. A spray patternator was fabricated for the selection of a suitable nozzle to have uniform distribution of the spray liquid. Experiments were conducted on a spray patternator through two types of spray nozzles (even flat fan nozzle TPE for banding application and standard flat fan nozzle TP for broadcasting application). Spray distribution was determined and compared by using single nozzle, at a height of 0.5 m under laboratory conditions. In addition, this paper examined the effect of spray fan angles 65 and 80° and liquid pressures 200 and 300 kPa on the spray distribution. The best distribution of the spray application was obtained by using banding nozzles, whereas the broadcasting nozzle gave an uneven spray distribution with a high peak just below the nozzle centre and taper off towards the edges of the spray pattern. For the two nozzle types tested, results revealed that increasing nozzle angle and pressure reduce the value of the coefficient of variation CV%. Key words: Static spray distribution, nozzle, patternator, coefficient of variation (CV).

Nonpolar a-GaN epilayers with reduced defect density using patterned r-plane sapphire substrates

Nonpolar a-GaN films were grown on patterned r-plane sapphire substrate (r-PSS) with hemispherical shape pattern by metalorganic chemical vapor deposition. Dislocations originating from the side edge of hemisphere patterns in flat sapphire substrate region were inclined to ~±60°. The initial GaN was elongated along the ridges of the hemisphere pattern and showed different crystal orientations. This was laterally overgrown by fast deposition from the flat sapphire substrate region. Defects in the a-GaN films on the hemisphere patterns were significantly reduced, because of the inclination of the defects and the epitaxial lateral overgrowth. In addition, additional defects such as voids and zigzag shaped prismatic stacking faults (PSFs) were generated on the top of the r-PSS. For the a-GaN films on the r-PSS, the densities of the basal stacking faults and partial dislocations were reduced to 8.0×105cm−1 and 8.4×109cm−2, respectively. Consequently, the nonpolar a-GaN films on the hemispherical r-PSS exhibited superior crystal quality with reduced defect density, even though additional PSFs were formed on the r-PSS.

Investigation of the Influence of Tyre Geometry on the Aerodynamics of Passenger Cars

It is well known that wheels are responsible for a significant amount of the total aerodynamic drag of passenger vehicles. Tyres, and mostly rims, have been the subject of research in the automotive industry for the past years, but their effect and interaction with each other and with the car exterior is still not completely understood. This paper focuses on the use of CFD to study the effects of tyre geometry (tyre profile and tyre tread) on road vehicle aerodynamics. Whenever possible, results of the numerical computations are compared with experiments. More than sixty configurations were simulated. These simulations combined different tyre profiles, treads, rim designs and spoke orientation on two car types: a sedan and a sports wagon. Two tyre geometries were obtained directly from the tyre manufacturer, while a third geometry was obtained from our database and represents a generic tyre which covers different profiles of a given tyre size. All geometries were deformed based on measured wind tunnel data under a defined load and rotating conditions of 100 kph. Results have shown that the main grooves consistently lead to a decrease of both drag and lift. The edge pattern however, did not show a clear trend for drag and lift with respect to the different configurations studied, although its influence was always more noticeable on the sports wagon. The larger profile of the generic tyre resulted in higher drag and lift values with relation to the tyres obtained from the manufacturer. For a given rim, a drag difference was observed between two tyre geometries with same profile but different tyre tread. These findings lead to the conclusion that tyre profile, as well as tyre pattern, are important to consider. These results were confirmed by wind tunnel tests. In conclusion, the work of aerodynamic optimization of rims cannot be separated from the tyre itself.

움직임 벡터의 정규화 및 에지의 패턴 분석을 이용한 복수 영상 기반 초해상도 영상 생성 기법

본 논문에서는 움직임 벡터의 정규화 및 윤곽선(edge)의 패턴 분석을 이용한 새로운 복수영상 기반의 초해상도(super resolution) 영상 생성 기법을 제안한다. 기존의 복수영상 기반의 초해상도 기법의 경우 입력 동영상을 구성하는 각 영상 간 부화소(sub-pixel) 단위의 움직임과 병진이동(global translation)만이 발생한다고 가정하여 기법의 적용이 제한적이다. 또한 이러한 제한에 강한 단일영상 기반의 초해상도 영상 생성 기법의 경우 보간 시 사용할 수 있는 정보량이 제한적이라는 단점이 있다. 본 논문에서는 기존 기법의 단점인 부화소 단위의 움직임에 대한 제한을 움직임 벡터의 정규화 기법을 통해 해결하고, 윤곽선 패턴 분석을 기반으로 한 2*2 블록 단위의 움직임 추정을 통해 병진이동에 대한 제한을 해결하였다. 또한 실험을 통하여 제안하는 기법이 기존의 이중선형(bi-linear)보간법, 단일영상과 복수영상 기반 초해상도 기법보다 우수하다는 것을 확인하였다. In this paper, we propose multi-frame based super resolution algorithm by using motion vector normalization and edge pattern analysis. Existing algorithms have constraints of sub-pixel motion and global translation between frames. Thus, applying of algorithms is limited. And single-frame based super resolution algorithm by using discrete wavelet transform which robust to these problems is proposed but it has another problem that quantity of information for interpolation is limited. To solve these problems, we propose motion vector normalization and edge pattern analysis for 2*2 block motion estimation. The experimental results show that the proposed algorithm has better performance than other conventional algorithms.

Edge pattern based demosaicking algorithm of color filter array

An efficient adaptive approximation demosaicking algorithm based on the sampled edge pattern was presented for mosaic images from Bayer color filter array. The proposed algorithm determined edge patterns by four nearest green values surrounding the green interpolation location. Then according to the edge patterns, different adaptive interpolation steps were applied. Simulations on 12 Kodak photos and 15 IMAX high-quality images showed that the proposed method outperformed the other four demosaicking methods (bilinear, effective color interpolation, Lu’s method and Chen’s method) for average color peak signal to noise ratios and maintained a relatively low complexity owing to constant color-difference interpolation step and a reasonable terminating condition of iteration.

Ant algorithms for image feature extraction

This paper extends on previous work in applying an ant algorithm to image feature extraction, focusing on edge pattern extraction, as well as the broader study of self-organisation mechanisms in digital image environments. A novel method of distributed adaptive thresholding is introduced to the ant algorithm, which enables automated distributed adaptive thresholding across the swarm. This technique is shown to increase performance of the algorithm, and furthermore, eliminates the requirement for a user set threshold, allowing the algorithm to autonomously adapt an appropriate threshold for a given image, or data set. Additionally this approach is extended to allow for simultaneous multiple-swarm multiple-feature extraction, as well as dynamic adaptation to changing imagery.

2A1-J07 エッジパターン特徴とハイライト特徴を用いた机上透明物体認識(ロボットビジョン(1))

This paper describes a method of recognition for transparent objects on the desk, using a monocular camera. First, we apply a machine leaning-based method using edge patterns to the transparent desktop object recognition. Edge patterns which appear in the local area of the image are represented by a probabilistic topic model. Edge pattern features indicating presences of specific edge patterns, are used for training a Support Vector Machine (SVM) binary classifier, which dscriminates between transparent objects and backgrounds. Then, we try to detect transparent objects in desk scenes using the classifier. Next, we define a highlight pattern feature describing highlight regions of objects. Highlight pattern features are represented by binarization of highlighted pixel ratio in local areas, and combined with edge pattern features to enhance the previous method. Finally, combined features are tested in cross-validation and object detection and shown to be superior to the previous edge pattern features.

Habitat Edge Contrast as an Indicator to Prioritize Sites for Ecological Restoration at the Landscape Scale

Forest restoration at the landscape level has required the development of criteria and methods to prioritize sites of restoration. In this study, we analyzed the spatial patterns of habitat contrast edge to prioritize sites for restoration in a protected area in southern Chile. The edge contrast index (ECON) was estimated and mapped for each pairwise combination of habitat type, based on community composition and structure ecological variables. Correlation length, as a measure of landscape connectivity, was calculated to analyze the effect of restoring high-contrast edge zones on focal habitat continuity. Approximately, 20% of the landscape area was composed of patches of high-contrast habitat edge (ECON ≥50%). Out of the total edge length, 91% corresponded to high-contrast edges between the focal habitat and forest plantations of Eucalyptus globulus and Pinus radiata and stands invaded by Acacia spp. Only 9% corresponded to low-contrast edges (< 0.5) with natural forests. The highest ECON corresponded to patches both invaded by alien species (80-90%) and planted with exotic tree species (60-70%) that were adjacent to the focal habitat patches. Zones of high contrast that were dissecting the focal habitat patches were prioritized for restoration. The correlation length increased from 1,822 to 2,211 m for the current and the restoration scenario, respectively. Landscape planning should strive to reduce edges between suitable and unsuitable habitats, taking into account edge sensitivity of forest-dependent species and the spread of invasive species.

科尔沁沙地家榆林的种子散布及幼苗更新

家榆是典型的风播植物, 在科尔沁沙地可以形成单一优势种林地。通过对林缘和孤立树不同方向从树基部向外的有序取样与林下和林窗的随机取样调查, 分析了家榆林下和林窗不同生境的种子沉降和幼苗分布特征、林缘和孤立树种子散布方向的差异性与规律性。结果表明, 家榆种子密度在林下生境阴坡和阳坡明显大于丘顶和丘底, 在林窗生境丘顶明显大于丘底。家榆向周围不同方向种子散布的距离和累积数量均有较大差异, 其中林缘和孤立树均以当地多逆风频率的西南方向最近, 累积数量也最少;孤立树以多顺风频率的东北方向最远, 累积数量也最多。林缘和孤立树共6个方向断面从树基部向外单位面积种子数量频度均适合于韦伯分布和对数-正态分布(<em>X_(α)</em>²<0.500)密度函数, 具有相同的种子散布格局。家榆幼苗密度在林下阴坡明显大于阳坡, 林下和林窗均为丘顶明显大于丘底。林缘19 m 内家榆幼苗呈连续分布。在科尔沁沙地, 如果不加限制或人为扰动, 家榆林不仅可以很好地进行自然更新, 而且可以在适宜的沙地生境逐渐扩大其分布空间。

Target Design and Recognition for 2-D Localization of Indoor Mobile Robots Using a Laser Sensor

Indoor mobile robots (IMR) can work autonomously if they have the capability to perform localization. This paper presents a design of a target that is used for laser sensor based IMR localization and an algorithm for recognizing the target in a noisy environment from the laser sensor measurements. An onboard laser sensor mounted on top of a rotary actuator is used to scan the entire front area of the IMR. The distance measurements obtained from the laser sensor are then be used to detect the uniquely designed target based on edge detection and pattern recognition techniques. This recognized target can then be used as a fiducial marker (whose global positions are known) to localize the IMR, i.e., to obtain estimates of the vehicle pose and location in a 2-D indoor environment. The target recognition method and hence the designed target is validated with experimental results.

형태학적 영상처리를 이용한 어체 측정 시스템 개발에 관한 연구

To manage, sort, and grade fishery resources, it is necessary to measure their morphometric characteristics. This labor-intensive task involves performing repetitive operations on land and on a research vessel. To reduce the amount of labor required, a vision-based automatic measurement system (VAMS) for the measurement of morphometric characteristics of flatfish, such as total length (TL), body width (BW), and body height (BH), has been developed as part of a database management system for fishery resources management. This system can also measure the mass (M) of flatfish. In the present study, we describe a morphological image processing algorithm for the measurement of certain characteristics of flatfish. This algorithm, which involves preprocessing, edge pattern matching, and edge point detection, is effective in cases where the flatfish being measured has a deformed tail and is randomly oriented. The satisfactory performance of the proposed algorithm is also demonstrated by means of experiments involving the measurement of the BW, TL and BH of a flatfish when it is straightened (BW : 117mm, TL : 329mm, BH : 24.5mm), when its tail is deformed, and when it is randomly oriented.

An Effective Approach to Achieve a Spin Gapless Semiconductor–Half‐Metal–Metal Transition in Zigzag Graphene Nanoribbons: Attaching A Floating Induced Dipole Field via π–π Interactions

AbstractUnder first‐principles computations, a simple strategy is identified to modulate the electronic and magnetic properties of zigzag graphene nanoribbons (zGNRs). This strategy takes advantage of the effect of the floating dipole field attached to zGNRs via π–π interactions. This dipole field is induced by the acceptor/donor functional groups, which decorate the ladder‐structure polydiacetylene derivatives with an excellent delocalized π‐conjugated backbone. By tuning the acceptor/donor groups, –C≡C– number, and zGNR width, greatly enriched electronic and magnetic properties, e.g., spin gapless semiconducting, half‐metallic, and metallic behaviors, with the antiferromagnetic−ferromagnetic conversion can be achieved in zGNRs with perfect, 57‐reconstructed, and partially hydrogenated edge patterns.

Inflammatory Myofibroblastic Tumor of Lung – Computed Tomographic Features in 20 Patients

Aim: To study the salient characteristic computed tomographic findings of inflammatory myofibroblastic tumor of lung. Materials and methods: We retrospectively reviewed the CT examinations of twenty histopathologically confirmed cases of inflammatory myofibroblastic tumor of lung and analyzed the involvement, predominant location, pattern of presentation, shape, edge, pattern and degree of enhancement and any atypical findings in those cases. Results: Fourteen cases presented as pulmonary nodules among which twelve as solitary while two cases as multiple pulmonary nodules. Six cases presented as masses. The location was in the parenchyma of the lung among all cases except two masses that were predominantly mediastinal and endobronchial respectively. All nodules demonstrated mild enhancement except one nodule showed moderate and another one marked enhancement. Four masses demonstrated mild enhancement whearas one showed moderate and another marked enhancement. Pleural surface abutting was noticed in one nodule and two masses. Stippled calcification was present in one mass while necrosis was noticed in two other cases that presented as mass. Mass were associated with consolidation in one and as cavity in another case. Conclusion: Although diagnosis of inflammatory myofibroblastic tumor of lung cannot be confirmed radiologically, certain features as presence of nodules or masses that enhance mildly in a patient with equivocal clinical and radiological presentation warrants its inclusion in the differential diagnosis. NJR I VOL 2 I ISSUE 1 18-24 Jan-June, 2012 DOI: http://dx.doi.org/10.3126/njr.v2i1.6974

SideKnot: Edge bundling for uncovering relation patterns in graphs

The node-link diagram is an intuitive way to depict a graph and present relationships between entities. Addressing the visual clutter induced by edge crossing and node-edge overlapping is a challenging task as the size of graph outgrows the visualization space. Many edge bundling methods are proposed to disclose high-level edge patterns. Though previous methods can successfully reveal the skeleton graph structure, the relation patterns at the individual node level can be overlooked. In addition, most edge bundling algorithms are computationally complex, which prevents them from scaling up for extremely large graphs. In this article, we extend SideKnot, an efficient edge bundling method to cluster and knot edges at the node side. Our proposed method is light, runs faster than most existing algorithms, and can reveal the relation patterns at the individual node level. Our results show that SideKnot can disclose a node's standing in the graph as well as the directional connection patterns to its peers.