Skew correction of business card images acquired in PDA

An efficient algorithm for rotational skew correction of business card images acquired in a PDA (personal digital assistant) camera is presented. The proposed method is composed of four parts: block adaptive binarisation (BAB), stripe generation, skew angle calculation and image rotation. In BAB, an input image is binarised block by block so as to lessen the effects of irregular illumination and shadow over the input image. In stripe generation, character string clusters are generated merging adjacent characters and their strings, and then only clusters useful for skew angle calculation are output as stripes. In skew angle calculation, the direction angles of the stripes are calculated using their central moments and then the skew angle of the input image is determined averaging the direction angles. In image rotation, the input image is rotated by the skew angle. Experimental results show that the proposed method yields root mean square error of 0.44/spl deg/ for test images of several types of business cards acquired by a PDA under various surrounding conditions.     

Soluble processed low-voltage and high efficiency blue phosphorescent organic light-emitting devices using small molecule host systems

We report low voltage driving and highly efficient blue phosphorescence organic light emitting diodes (PHOLEDs) fabricated by soluble process. A soluble small molecule mixed host system consisting of hole transporting 4,4’,4’’ tris(N-carbazolyl)triphenylamine (TCTA) and bipolar carrier transporting 2,6-bis(3-(carbazol-9-yl)phenyl)pyridine (26DCzPPy) exhibits high solubility with smooth surface properties. Moreover, this small molecule host shows the smoothest morphological property similar to a vacuum deposited amorphous film. A low driving voltage of 5.4 V at 1000 cd/m² and maximum external quantum efficiency 14.6% obtained in the solution processed blue PHOLEDs are useful for large area low cost manufacturing.     

Design and analysis of cooperative wireless data access algorithms in multi-radio wireless networks

In the future, most mobile nodes will have multiple radio interfaces, and this feature can be exploited to reduce the transmission cost in wireless data access applications. In this work, we propose cooperative poll-each-read (CoopPER) and cooperative callback (CoopCB) wireless data access algorithms with strong consistency in multi-radio wireless networks. In addition, we investigate CoopPER and CoopCB in heterogeneous wireless networks where CoopPER and CoopCB nodes are mixed. Extensive simulations are done to show the effects of access-to-update ratio, data access pattern, cache size, and cooperation range. Simulation results demonstrate that CoopPER and CoopCB can significantly reduce the expensive transmission cost over wireless links.     

Ultrathin Sticker‐Type ZnO Thin Film Transistors Formed by Transfer Printing via Topological Confinement of Water‐Soluble Sacrificial Polymer in Dimple Structure

To create ultrathin sticker‐type electronic devices that can be attached to unconventional substrates, it is highly desirable to develop printable membrane‐type electronics on a handling substrate and then transfer the printing to a target surface. A facile method is presented for high‐efficiency transfer printing by controlling the interfacial adhesion between a handling substrate and an ultrathin substrate in a systematic manner under mild conditions. A water‐soluble sacrificial polymer layer is employed on a dimpled handling substrate, which enables the topological confinement of the polymer residue inside and near the dimples during the etching and drying processes to reduce the interfacial adhesion gently, creating a high yield of transfer printing in a deterministic manner. As an example of an electronic device that was created using this method, a highly flexible sticker‐type ZnO thin film transistor was successfully developed with a thickness of 13 μm including a printable ultrathin substrate, which can be attached to various substrates, such as paper, plastic, and stickers.     

CARD资源发现架构在无线传感网络中的性能研究

(西北工业大学计算机学院,陕西西安,710072)【摘要】CARD架构适用于大规模、高查询率、每次查询的数据传输量较小的Ad-hoc网络,它的核心目标是降低网络资源发现能耗,延长网络生命周期。文章首先介绍了CARD架构的结构;然后,建立了该架构的数学模型,该模型以无线传感器网络为目标场景,并推导出CARD架构的能耗和查询成功率与各个参数之间的函数关系;最后,根据该模型对CARD架构的能耗和查询成功率进行了理论分析,为CARD架构的参数选择提供了可靠的依据,并为对架构的进一步优化打下了坚实基础。     

Neuro-Glia-Vascular-on-a-Chip System to Assess Aggravated Neurodegeneration via Brain Endothelial Cells upon Exposure to Diesel Exhaust Particles

Air pollution induces neurodegeneration, including cognitive deficits, neuroinflammation, and disruption of the blood–brain barrier. The mechanisms underlying air pollution-mediated neurodegeneration have not yet been fully elucidated given the limited knowledge on intercellular interactions. A brain-on-a-chip platform is presented comprising neurons, glia, and brain endothelial cells (bECs; neuro-glia-vascular, NGV) and diesel exhaust particle (DEP)-induced neurodegeneration is evaluated with a particular focus on the intercellular interactions. DEP exposure in the NGV model yields Alzheimer's disease-like signatures, including amyloid beta accumulation, tau phosphorylation, hydrogen peroxide (H₂O₂)/reactive oxygen species (ROS) production, and neuronal cell death. bEC-secreted granulocyte-macrophage colony-stimulating factor (GM-CSF) stimulates microglial activation and the overproduction of H₂O₂/ROS in microglia, suggesting that the bEC-microglia-neuron is a neurodegeneration cascade. Pharmacological inhibition at each step of the cascade, including GM-CSF neutralization, microglial activation suppression, and ROS scavenging, prohibits neurodegeneration in the NGV model. Therefore, intercellular interactions should be further studied of air pollution-induced neurodegeneration.     

Double S-Shaped Polarization – Voltage Curve and Negative Capacitance from Al2O3-Hf0.5Zr0.5O2-Al2O3 Triple-Layer Structure

The negative capacitance (NC) effect, recently discovered in a fluorite-based ferroelectric thin film, has attracted great attention as a rescue to overcome the scaling limitations of the conventional memory and logic devices of highly integrated circuits. The NC effect manifesting an S-shaped polarization–voltage (P–V) curve is initially interpreted by a 1-dimensional Landau Ginzburg Devonshire (LGD) model. However, a series of recent studies have found that this effect can also be explained by the inhomogeneous stray field energy (ISE) model. In this study, by extending the ISE model in the ferroelectric (FE)-dielectric (DE) layered structure, an analytical model that considers the influence of the interfacial screening charge distribution is presented. This model showed that the NC effect in the FE-DE heterostructure can be manifested in various forms other than a single S-shaped P–V curve. In particular, a double S-shaped P–V curve is expected from the fully compensated anti-parallel domain structure, confirmed experimentally in the actual Al₂O₃/(Hf_0.5Zr_0.5)O₂/Al₂O₃ triple-layer structure. Furthermore, to reveal the origin of the double S-shaped P–V curve, a multidomain LGD model is presented. It is confirmed that this phenomenon is attributed to the evolution of inhomogeneous stray field energy.     

Epoxy/BaTiO/sub 3/ composite films and pastes for high dielectric constant and low-tolerance embedded capacitors fabrication in organic substrates

Epoxy/BaTiO/sub 3/ composite embedded capacitor films (ECFs) were newly designed for high dielectric constant and low-tolerance (less than /spl plusmn/5%) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of a specially formulated epoxy resin and latent curing agent, and in terms of a coating process, a comma roll coating method is used for uniform film thickness in large area. The dielectric constant of ECF in high frequency range (0.5/spl sim/3 GHz) is measured using the cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. The dielectric constant is calculated by observing the frequencies of the resonant cavity modes. Calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of the epoxy matrix. The dielectric relaxation of barium titanate (BaTiO/sub 3/: BT) powder is not observed within measured frequency. An alternative material for embedded capacitor fabrication is epoxy/BaTiO/sub 3/ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming a capacitor partially in the desired part. However, the screen printing makes surface irregularities during mask peel-off. Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, a dielectric layer with improved thickness uniformity is successfully demonstrated. Using epoxy/BaTiO/sub 3/ composite ECP, a dielectric constant of 63 and specific capacitance of 5.1 nF/cm/sup 2/ were achieved.     

Small molecule interlayer for solution processed phosphorescent organic light emitting device

Using a 4,4′,4′′-tris(N-carbazolyl)-triphenylamine (TCTA) small molecule interlayer, we have fabricated efficient green phosphorescent organic light emitting devices by solution process. Significantly a low driving voltage of 3.0 V to reach a luminance of 1000 cd/m² is reported in this device. The maximum current and power efficiency values of 27.2 cd/A and 17.8 lm/W with TCTA interlayer (thickness 30 nm) and 33.7 cd/A and 19.6 lm/W with 40 nm thick interlayer are demonstrated, respectively. Results reveal a way to fabricate the phosphorescent organic light emitting device using TCTA small molecule interlayer by solution process, promising for efficient and simple manufacturing.