Using Sorted Switching Median Filter to remove high-density impulse noises

We propose a novel Sorted Switching Median Filter (i.e. SSMF) for effectively denoising extremely corrupted images while preserving the image details. The center pixel is considered as “uncorrupted” or “corrupted” noise in the detecting stage. The corrupted pixels that possess more noise-free surroundings will have higher processing priority in the SSMF sorting and filtering stages to rescue the heavily noisy neighbors. Five noise models are considered to assess the performance of the proposed SSMF algorithm. Several extensive simulation results conducted on both grayscale and color images with a wide range (from 10% to 90%) of noise corruption clearly show that the proposed SSMF substantially outperforms all other existing median-based filters.     

Soldering of solution-processed organic vertical transistor and light-emitting diode on separate glass substrates by tin micro-balls

The vertical organic space-charge-limited transistor made of P3HT and small-molecule phosphorescent organic light-emitting diode (OLED) are made on two separate glass substrate by blade coating, then soldered vertically together by tin balls with 40 μm diameter. The soldering is done by hot wind of 150 °C for 5 min Contact resistance is only 10 Ω. The vertical transistor is annealed at 150 °C for 5 min before soldering to enhance the output current up to 25 mA/cm² and give high thermal stability. Both OLED and the annealed vertical transistor are not affected by the soldering process. The vertical transistor has 1/4 of the OLED area and turns on the bottom-emission white OLED up to 300 cd/m² and orange OLED up to 600 cd/m². The entire operation is within 8 V. OLED and transistor array can therefore be made on separate glass substrates then soldered together to form the display.     

Structure‐Properties Relationship in Iron Oxide‐Reduced Graphene Oxide Nanostructures for Li‐Ion Batteries

Non‐aqueous sol‐gel routes involving the reaction of metal oxide precursors in organic solvents (e.g., benzyl alcohol) at moderate temperature and pressure, offer advantages such as high purity, high reproducibility and the ability to control the crystal growth without the need of using additional ligands. In this paper, a study carried out on a series of iron oxide/reduced graphene oxide composites is presented to elucidate a structure‐properties relationship leading to an improved electrochemical performance of such composites. Moreover, it is demonstrated that the easy production of the composites in a variety of temperature and composition ranges, allows a fine control over the final particles size, density and distribution. The materials obtained are remarkable in terms of the particle's size homogeneity and dispersion onto the reduced graphene oxide surface. Moreover, the synthesis method used to obtain the graphene oxide clearly affects the performances of the final composites through the control of the restacking of the reduced graphene oxide sheets. It is shown that a homogeneous and less defective reduced graphene oxide enables good electrochemical performances even at high current densities (over 500 mAh/g delivered at current densities as high as 1600 mA/g). The electrochemical properties of improved samples reach the best compromise between specific capacity, rate capability and cycle stability reported so far.     

Bacterial pyomyositis: MRI and clinical correlation

OBJECTIVE: To characterize the findings of magnetic resonance imaging (MRI) of bacterial pyomyositis (PM) and correlate these data with the clinical information. MATERIALS AND METHODS: Eighty-one patients were diagnosed with PM in our institute between 1997 and 2003. Of these, 40 patients (21 male, 19 female; mean age, 53 years) also underwent MRI examination. The clinical manifestation underlying medical problems and the characteristics of MRI were analyzed. Thirty of the patients received surgical intervention or image-guided drainage/aspiration of the abscess along with administration of antibiotics, while the remaining 10 patients were promptly treated solely with antibiotics. RESULTS: Thirty-one of 40 patients had underlying medical problems. These involved diabetes mellitus (DM, n = 16), malignancies including cervical cancer, prostate cancer, non-Hodgkin's lymphoma and acute lymphocytic leukemia (n = 10, one case also had DM), autoimmune disease or asthma with long-term steroid usage (n = 4, one case also had DM), liver cirrhosis (n = 2) and chronic renal insufficiency (n = 1). Four patients had no abscess formation at presentation (invasive or early purulent stage), while the remaining 36 cases presented with at least one abscess (purulent stage). Patients older than 40 years or DM patients tended to have larger abscess(s) (P < .05). Gadolinium-enhanced images demonstrated either thick (n = 12) or thin rim enhancement (n = 24) of the abscess wall. For those 10 patients promptly treated solely with antibiotics, nine demonstrated thin rim enhancement of the abscess (P < .05). CONCLUSION: Magnetic resonance imaging plays an important role in the early recognition of bacterial PM. By precisely demarcating the extent of the disease, MRI can allow planning prompt antibiotic treatment combined with or without interventional procedures.     

A Versatile Fluoro‐Containing Low‐Bandgap Polymer for Efficient Semitransparent and Tandem Polymer Solar Cells

The versatility of a fluoro‐containing low band‐gap polymer, poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b’]dithiophene)‐alt‐4,7‐(5‐fluoro‐2,1,3‐benzothia‐diazole)] (PCPDTFBT) in organic photovoltaics (OPVs) applications is demonstrated. High boiling point 1,3,5‐trichlorobenzene (TCB) is used as a solvent to manipulate PCPDTFBT:[6,6]‐phenyl‐C₇₁‐butyric acid methyl ester (PC₇₁BM) active layer morphology to obtain high‐performance single‐junction devices. It promotes the crystallization of PCPDTFBT polymer, thus improving the charge‐transport properties of the active layer. By combining the morphological manipulation with interfacial optimization and device engineering, the single‐junction device exhibits both good air stability and high power‐conversion efficiency (PCE, of 6.6%). This represents one of the highest PCE values for cyclopenta[2,1‐b;3,4‐b’]dithiophene (CPDT)‐based OPVs. This polymer is also utilized for constructing semitransparent solar cells and double‐junction tandem solar cells to demonstrate high PCEs of 5.0% and 8.2%, respectively.     

Raman and infrared spectra, conformational stability, ab initio calculations and assignment of fundamentals for 1-bromo-3-fluoropropane

The infrared and Raman spectrum of 1-bromo-3-fluoropropane is reported in the gas, liquid, amorphous solid and annealed polycrystalline states. Only one of the five possible conformers is stable in the crystal, designated the C conformer. The disordered phases show the presence of several other conformers of higher energy, due entirely to conformers designated B and D. Ab initio calculations were performed as rhf/4-31g*/MIDI-4*, rhf/6-31g* and mp2/6-31g* (both frozen core and full electron correlation) for all five conformers. The scaled harmonic force field obtained using the mp2 = full/6-31g* level of the theory is reported for the most stable conformer together with an assignment of fundamentals and potential energy distributions for local symmetry coordinates. Selected computational results are reported for all conformers together with scaled and unscaled wavenumbers and infrared and Raman intensities. The temperature dependent Raman spectrum is reported from room temperature to -100 degrees C. Only three of the five possible conformers can be identified in this spectrum, and there is no evidence of the other two. The energy differences between conformers in the liquid phase were found experimentally to be 132+/-27, 232+/-46 and 106+/-30 cm(-1), respectively between the D and C, B and C and D and B conformers. These differences are substantially less than the differences calculated ab initio at the highest level of the theory used, suggesting that energy differences were decreased by large dipole-dipole interactions present in the liquid but not in the gas.     

Structural determination of sphingomyelin by tandem mass spectrometry with electrospray ionization

Alkaline metal adduct ions of sphingomyelin were formed by electrospray ionization in positive ion mode. Under low energy collisionally activated dissociation (CAD), the product ion spectra yield abundant fragment ions representative of both long chain base and fatty acid which permit unequivocal determination of the structure. Tandem spectra obtained by constant neutral loss scanning permit identification of sphingomyelin class and specific long chain base subclass in the mixture. The fragmentation pathways under CAD were proposed, and were further confirmed by source CAD tandem mass spectrometry. The total analysis of sphingomyelin mixtures from bovine brain, bovine erythrocytes, and chicken egg yolk is also presented.     

Characterization of phosphatidylinositol, phosphatidylinositol-4-phosphate, and phosphatidylinositol-4,5-bisphosphate by electrospray ionization tandem mass spectrometry: A mechanistic study

Structural characterization of phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PI-4P), and phosphatidylinositol-4,5-bisphosphate (PI-4,5-P2) by collisionally activated dissociation (CAD) tandem mass spectrometry with electrospray ionization is described. In negative ion mode, the major fragmentation pathways under low energy CAD for PI arise from neutral loss of free fatty acid substituents ([M - H - RxCO2H]-) and neutral loss of the corresponding ketenes ([M - H - R'xCH=C=O]-), followed by consecutive loss of the inositol head group. The intensities of the ions arising from neutral loss of the sn-2 substituent as a free fatty acid ([M - H - R2CO2H]-) or as a ketene ([M - H - R'2CH=C=O] ) are greater than those of ions reflecting corresponding losses of the sn-1 substutient. This is consistent with our recent finding that ions reflecting those losses arise from charge-driven processes that occur preferentially at the sn-2 position. These features permit assignment of the position of the fatty acid substituents on the glycerol backbone. Nucleophilic attack of the anionic phosphate onto the C-1 or the C-2 of the glycerol to which the fatty acids attached expels sn-1 (R1CO2-) or sn-2 (R2CO2-) carboxylate anion, respectively. This pathway is sterically more favorable at sn-2 than at sn-1. However, further dissociations of [M - H - RxCO2H - inositol] , [M - H - RxCO2H]-, and [M - H - RxCH=C=O]- precursor ions also yield RxCO2- ions, whose abundance are affected by the collision energy applied. Therefore, relative intensities of the RxCO2- ions in the spectrum do not reflect their positions on the glycerol backbone and determination of their regiospecificities based on their ion intensities is not reliable. The spectra also contain specific ions at m/z 315, 279, 259, 241, and 223, reflecting the inositol head group. The last three ions are also observed in the tandem spectra of the [M - H]- ions of phosphatidylinositol monophosphate (PI-P) and phosphatidylinositol bisphosphate (PI-P2), in addition to the ions at m/z 321 and 303, reflecting the doubly phosphorylated inositol ions. The PI-P2 also contains unique ions at m/z 401 and 383 that reflect the triply phosphorylated inositol ions. The [M - H]- ions of PI-P and PI-P2 undergo fragmentation pathways similar to that of PI upon CAD. However, the doubly charged ([M - 2H]2-) molecular ions undergo fragmentation pathways that are typical of the [M - H]- ions of glycerophosphoethanolamine, which are basic. These results suggest that the further deprotonated gaseous [M - 2H]2 ions of PI-P and PI-P2 are basic precursors.     

A seamless handoff scheme for IEEE 802.11 wireless networks

The advance of computer network technologies such as IEEE 802.11 wireless local area network has made it possible for users to connect to Internet almost anywhere. A mobile node (MN) is likely to move between different base stations while running applications. The IETF has defined the Mobile IP (MIP) to allow MNs to maintain their communication uninterrupted while roaming across different IP subnets. However, the mechanisms defined in MIP may cause undesired connection disruptions or packet losses, which will significantly degrade the quality of real‐time applications. It is an important and challenging issue to support seamless handoff management. To achieve seamless handoff, we propose a unified scheme to address application quality degradation. Our main contribution is the concept and implementation of utilising buffering and resending method to eliminate the packet losses while keeping the end‐to‐end delay of real‐time traffic flow in an acceptable value. The NS‐2 simulation results show that our proposed scheme can significantly maintain application quality during layer‐2 and ‐3 handoffs. Copyright © 2011 John Wiley & Sons, Ltd.