Autonomic load balancing of flow monitors

In monitoring flows at routers for flow analysis or deep packet inspection, the monitor calculates hash values from the flow ID of each packet arriving at the input port of the router. Therefore, the monitors must update the flow table at the transmission line rate, so high-speed and high-cost memory, such as SRAM, is used for the flow table. This requires the monitors to limit the monitoring target to just some of the flows. However, if the monitors randomly select the monitoring targets, multiple routers on the route will sometimes monitor the same flow, or no monitors will monitor a flow. To maximize the number of monitored flows in the entire network, the monitors must select the monitoring targets while maintaining a balanced load among them. We propose an autonomous load-balancing method where monitors exchange information on monitor load only with adjacent monitors. Numerical evaluations using the actual traffic matrix of Internet2 show that the proposed method improves the total monitored flow count by about 50% compared with that of independent sampling. Moreover, we evaluate the load-balancing effect on 36 backbone networks of commercial ISPs.     

An architecture framework for an adaptive extensible processor

To improve the performance of embedded processors, an effective technique is collapsing critical computation subgraphs as application-specific instruction set extensions and executing them on custom functional units. The problem with this approach is the immense cost and the long times required to design a new processor for each application. As a solution to this issue, we propose an adaptive extensible processor in which custom instructions (CIs) are generated and added after chip-fabrication. To support this feature, custom functional units are replaced by a reconfigurable matrix of functional units (FUs). A systematic quantitative approach is used for determining the appropriate structure of the reconfigurable functional unit (RFU). We also introduce an integrated framework for generating mappable CIs on the RFU. Using this architecture, performance is improved by up to 1.33, with an average improvement of 1.16, compared to a 4-issue in-order RISC processor. By partitioning the configuration memory, detecting similar/subset CIs and merging small CIs, the size of the configuration memory is reduced by 40%.     

Fabrication of 5.8‐in. OTFT‐driven flexible color AMOLED display using dual protection scheme for organic semiconductor patterning

Abstract— A 5.8‐in. wide‐QQVGA flexible color active‐matrix organic light‐emitting‐diode (AMOLED) display consisting of organic thin‐film transistors (OTFTs) and phosphorescent OLEDs was fabricated on a plastic film. To reduce the operating voltage of the OTFTs, Ta₂O₅ with a high dielectric constant was employed as a gate insulator. Pentacene was used for the semiconductor layer of the OTFTs. This layer was patterned by photolithography and dry‐etched using a dual protection layer of poly p‐xylylene and SiO₂ film. Uniform transistor performance was achieved in the OTFT backplane with QQVGA pixels. The RGB emission layers of the pixels were formed by vacuum deposition of phosphorescent small molecules. The resulting display could clearly show color moving images even when it was bent and operated at a low driving voltage (below 15 V).     

High aspect ratio fabrication method using O2 RIE and electroplating

A polyimide-based process for the fabrication of vertical structures with high aspect ratio has been developed. O₂ reactive ion etching (O₂ RIE) has been employed in the polyimide processing. Achieved etching characteristics of the O₂ RIE system are: 4.0 m/min etching rate, 15 aspect ratio, 75 m etching depth. Polyimide has excellent chemical and thermal properties which makes it a good building material for micromachines. Polyimide could be also used as molds for electroplating. Electroplated copper structures were formed in the polyimide molds and metal gears were fabricated by these fabrication technologies. New possibilities for micromachining were opened by the use of O₂ RIE and electroplating.This work was supported by Japanese ministry of Education Science and Culture under a grant-in-Aid No. 03102001.     

High-rate Decoupled Water Electrolysis System Integrated with α-MoO3 as a Redox Mediator with Fast Anhydrous Proton Kinetics

Hydrogen is a promising alternative to fossil fuels that can reduce greenhouse gas emissions. Decoupled water electrolysis system using a reversible proton storage redox mediator, where the oxygen evolution reaction and hydrogen evolution reaction are separated in time and space, is an effective approach to producing hydrogen gas with high purity, high flexibility, and low cost. To realize fast hydrogen production in such a system, a redox mediator capable of releasing protons rapidly is required. Herein, α-MoO₃, with an ultrafast proton transfer property that can be explained by a dense hydrogen bond network in the lattice oxygen arrays of HxMoO₃, is examined as a high-rate redox mediator for fast hydrogen production in acidic electrolytes. The α-MoO₃ redox mediator shows both a large capacity of 204 mAh g⁻¹ and fast hydrogen production at a current rate of 10 A cm⁻²(≈153 A g⁻¹), outperforming most of the previously reported solid-state redox mediators.     

Frequency Stability Improvement of a Two-Mode Stabilized 633-nm He-Ne Laser

The red side (lower-frequency) mode of a two-mode stabilized 633-nm He-Ne laser has been locked to the hyperfine structure of the P() line of (127)I(2) by means of frequency modulation spectroscopy enhanced by an external optical cavity. Both the red side and blue side (higher-frequency) modes of the laser exhibit a frequency stability of 2.3 x 10(-11) tau(-1/2). In addition, the frequency fluctuations of the blue side mode are detected by a Fabry-Perot cavity and compensated through an acousto-optic frequency shifter. The short-term stability of better than 3 x 10(-11) is attained for integration times of between 2 x 10(-3) and 2 x 10(-1) s.     

Development of a pulse control-type MEMS microrobot with a hardware neural network

This article presents the micro-electro-mechanical systems (MEMS) microrobot which demonstrates locomotion controlled by hardware neural networks (HNN). The size of the microrobot fabricated by the MEMS technology is 4 × 4 × 3.5 mm. The frame of the robot is made of silicon wafer, and it is equipped with a rotary-type actuator, a link mechanism, and six legs. The rotary-type actuator generates rotational movement by applying an electrical current to artificial muscle wires. The locomotion of the microrobot is obtained by the rotation of the rotary-type actuator. As in a living organism, the HNN realized robot control without using any software programs, A/D converters, or additional driving circuits. A central pattern generator (CPG) model was implemented as an HNN system to emulate the locomotion pattern. The MEMS microrobot emulated the locomotion method and the neural networks of an insect with the rotary-type actuator, the link mechanism, and the HNN. The microrobot performed forward and backward locomotion, and also changed direction by inputting an external trigger pulse. The locomotion speed was 0.325 mm/s and the step width was 1.3 mm.     

Effects of plastic strain amplitudes on non-proportional cyclic plasticity

Summary A series of plastic strain controlled cyclic tests was performed to facilitate the modelling of cyclic plasticity under general multiaxial loading conditions. The tests were carried out by applying combined axial force and torque to thin-walled tubular specimens of type 316 stainless steel at room temperature. Torsional and circular cycles of the equivalent plastic strain amplitude (von Mises type) ofe ^p /2=0.1, 0.2 and 0.4% were specified.The results showed that the cyclic hardening under the circular cycles is 1.5–1.8 times as large as that under the torsional cycles of the same value ofe ^p /2 in the saturated state. It was also observed that, in the case of torsional cycles, these saturated values are not affected by the sequence of plastic strain cycles in the past, while in the case of circular cycles, they are affected by the cycles of larger amplitudes. Furthermore, it was elucidated that this memory effect depends only on the cycles of the largest amplitude in the past.With 12 Figures     

Identification of chemical oviposition stimulants from rice grain forSitophilus zeamais motschulsky (Coleoptera,Curculionidae)

Chemical components stimulating oviposition bySitophilus zeamais in rice grain were isolated from rice bran and were found to be a mixture of ferulates, diglycerides, and free sterols. Oviposition preference of the species can be induced by synergistic action of these compounds.