A QoS-aware routing mechanism for multi-channel multi-interface ad-hoc networks

To accommodate real-time multimedia application while satisfying application QoS requirements in a wireless ad-hoc network, we need QoS control mechanisms. In this paper, we propose a new routing mechanism to support real-time multimedia communication by efficiently utilize the limited wireless network capacity. Our mechanism considers a wireless ad-hoc network composed of nodes equipped with multiple network interfaces to each of which a different wireless channel can be assigned. By embedding information about channel usage in control messages of OLSRv2, each node obtains a view of topology and bandwidth information of the whole network. Based on the obtained information, a source node determines a logical path with the maximum available bandwidth to satisfy application QoS requirements. Through simulation experiments, we confirmed that our proposal effectively routed multimedia packets over a logical path avoiding congested links. As a result, the load on a network is well distributed and the network can accommodate more sessions than QOLSR. We also conducted practical experiments using wireless ad-hoc relay nodes with four network interfaces and verified the practicality of our proposal.     

Gold Nanoparticle and Gold Nanorod Embedded PEDOT:PSS Thin Films as Organic Thermoelectric Materials

We report the thermoelectric properties of organic–inorganic hybrid thin films composed of conductive polymer, poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and inorganic gold nanomaterials. Two kinds of material with different shapes, namely rod-shaped gold nanorods (AuNRs) and spherical gold nanoparticles (AuNPs), were used in this study. The PEDOT:PSS/AuNR hybrid films showed an enhancement in electrical conductivity (σ ≈ 2000 S cm^?1) and concurrently a decrease in the Seebeck coefficient (S ≈ 12 μV K^?1) with increase in the AuNR concentration. This behavior indicates the presence of the hybrid effect of AuNR on the thermoelectric properties. From scanning electron microscopy (SEM) observation of the highly concentrated PEDOT:PSS/AuNR hybrid films, the formation of a percolated structure of AuNRs was confirmed, which probably contributed to the large enhancement in σ. For the highly concentrated PEDOT:PSS/AuNP films, a dense distribution of AuNPs in the film was also observed, but this did not lead to a major change in the σ value, probably due to the less conductive connections between NPs. This suggests that one-dimensional particles with larger aspect ratio (rods and wires) are favorable nanocomponents for development of highly conductive hybrid materials.     

Detection of spicules on mammogram based on skeleton analysis

Existence of spicules is one of important clues of malignant tumors. This paper presents a new image processing method for the detection of spicules on mammogram. Spicules can be recognized as line patterns radiating from the center of tumor. To detect such characteristic patterns, line skeletons and a modified Hough transform are proposed. Line skeleton processing is effective in enhancing spinal axes of spicules and in reducing the other skeletons. The modified Hough transform is applied to line skeletons and radiating line structures are obtained. Experiments were made to test the performance of the proposed method. The system was designed using 19 training images, for which one normal case was recognized to be star-shaped. The other case were recognized correctly. Another experiments using 34 test images were also performed. The correct classification rate was 74%. These results shows the effectiveness of the proposed method.     

Numerical analysis of coupled transport and reaction phenomena in an anode-supported flat-tube solid oxide fuel cell

Heat and mass transfer with electrochemical reaction in an anode-supported flat-tube solid oxide fuel cell (FT-SOFC) is studied by means of three-dimensional numerical simulation. The distributions of the reaction fields in the anode-supported FT-SOFC are found to be similar to those in the planar SOFC with co-flow arrangement. However, in comparison with the latter, the concentration and activation overpotentials of the former can be reduced by additional reactant diffusion through the porous rib of the fuel channel. Parametric survey reveals that, for a fixed activation overpotential model, the output voltage can be improved by increasing the pore size of anode, while the cross-sectional geometry has smaller effect on the cell performance. Based on the results of three-dimensional simulation, we also develop a simplified numerical model of anode-supported FT-SOFC, which takes into account the concentration gradients in the thick anode of complex cross-sectional geometry. The simplified model can sufficiently predict the output voltage as well as the distributions of temperature and current density with very low computational cost. Thus, it can be used as a powerful tool for surveying wide range of anode-supported FT-SOFC design parameters.     

InxGa1−xAs ohmic contacts to n-type GaAs with a tungsten nitride barrier

Significant reduction of the contact resistance of In_0.7Ga_0.3As/Ni/W contacts (which were previously developed by sputtering in our laboratory) was achieved by depositing a W₂N barrier layer between the Ni layer and W layer. The In_0.7Ga_0.3 As/Ni/W₂N/W contact prepared by the radio-frequency sputtering technique showed the lowest contact resistance of 0.2 Ωmm after annealing at 550°C for 10 s. This contact also provided a smooth surface, good reproducibility, and excellent thermal stability at 400°C. The polycrystalline W₂N layer was found to suppress the In diffusion to the contact surface, leading to improvement of the surface morphology and an increase in the total area of the In_xGa−As between metal and the GaAs substrate. These improvements are believed to reduce the contact resistance.     

Formation of a step-free InAs quantum well selectively grown on a GaAs (111)B substrate

We investigated the possibility of forming a step-free quantum well structure. A step-free InAs monolayer was grown on a selectively grown mesa by controlling surface phases with in-situ monitoring of surface photo-absorption. We selectively grew a GaAs buffer at 800°C and cooled the sample keeping the (2×2)-like As stabilized surface. Atomic force microscopy (AFM) observation demonstrated that fully step-free surfaces were formed on the 8 μm wide mesa. Then, a monolayer-thick InAs was formed on this step-free surface and this InAs layer was capped by GaAs under the (2×2)-like condition. The quantum level of the step-free InAs layer was evaluated by spatially resolved photoluminescence (μPL) measurement. Uniform PL intensity and the lack of a double layer peak indicated the formation of a step-free InAs quantum well, which was in good agreement with AFM observation.     

氟伐他汀对2型糖尿病合并高胆固醇血症患者的抗氧化作用

目的调查氟伐他汀对2型糖尿病合并高胆固醇血症患者体内氧化压力的影响以及与降脂作用的相关性。方法糖尿病合并高脂血症患者41例,男21例,女20例,平均年龄（56．7±6．0）岁,均在日本弘前大学附属医院收集。每晚服用20mg氟伐他汀,于用药前及用药后4、8、12周分别测定血浆中低密度脂蛋白（LDL）,LDL size、LHPO、TBARS的动态变化。结果血浆LHPO,TBARS、LDL—C在用药的第8周（分别为19．4±8．1 vs43.3±13．1nmol／mg LDLpm;5．33±0．97vs8．83±1．11nmol／mL;125±9vs157±12mg／dL,P〈0．05）和12周（分别为14．4±5．1vs43．3±13．1nmol／mg LDLpro;2．3±0．3vs8．83±1．11nmol／mL;131±5vs157±12mg／dL,P〈0．05）明显降低,LDL size无统计学差异。结论氟伐他汀能够显著降低患者血中的LHPO、TBARS、LDL,表明对2型糖尿病合并高脂血症患者有抗氧化作用．且与其抗血脂的作用相关．     

Influence of stimulated Brillouin scattering on nonlinear distortion in SCM video transmission

It is shown analytically that nonlinear distortions are induced by stimulated Brillouin scattering in subcarrier multiplexed systems. They are expressed as a function of the additional loss of the transmission fibre which is induced by stimulated Brillouin scattering. Experimental results well support the theoretical conclusions.<>     

Spatial mapping of electronic states in κ-(BEDT-TTF)2X using infrared reflectivity

We review our recent work on spatial inhomogeneity of the electronic states in the strongly correlated molecular conductors κ-(BEDT-TTF)₂X. Spatial mapping of infrared spectra (SMIS) is used for imaging the distribution of the local electronic states. In molecular materials, the infrared response of the specific molecular vibration mode with a strong electron–molecular vibration coupling can reflect the electronic states via the change in the vibration frequency. By spatially mapping the frequency shift of the molecular vibration mode, an electronic phase separation has been visualized near the first-order Mott transition in the bandwidth-controlled organic conductor κ-(BEDT-TTF)₂Cu[N(CN)₂]Br. In addition to reviewing SMIS of the phase separation, we briefly mention the electronic and optical properties of κ-(BEDT-TTF)₂X.