In this paper, we base on region-based disk layout and propose a data placement technique and it associated disk scheduling policy for providing periodical video broadcast services. We present a quantitative study and design algorithms, while still maintains the quality of service, for (1) placing video data on disk, and (2) simultaneously serving of maximum number of broadcast channels with minimal data buffer. We also develop a model that relates disk device characteristics to maximizing the disk utilization.
In this article, the new multi-polarity helix transform for ternary logic functions has been introduced. In addition, an extended dual polarity property that had been used to optimize Kronecker and quaternary Fixed-Polarity Reed-Muller (FPRM) expressions has been applied to generate efficiently the multi-polarity helix transform over GF(3). The experimental results for the transform are compared with the well known ternary Reed-Muller transform and it was found that the helix transform is quite efficient in terms of non-zero spectral coefficients and corresponding memory storage.
This paper describes optical frequency comb generation using optical single-sideband modulation technique. We can obtain optical frequency shift using the singnal-sideband modulator consisting of four optical phase modulators, where the frequency shift is precisely equal to that of an rf-signal fed to the modulator. A series of optical spectral components can be generated by using an optical fiber loop having an optical single-sideband modulator.
A φ0.8mm micro-solid propellant rocket array thruster for simple attitude control of a 10kg class micro-spacecraft was tested in vacuum. The micro-thruster uses boron/potassium nitrate propellant (NAB), because NAB has ignition temperature as low as 500°C, and easily start to burn in vacuum. For a half of the rockets, an ignition aid (RK) was also loaded. Ignition was succeeded in vacuum with NAB + RK and NAB. The maximum impulse thrust of 4.6 × 10-4 Ns, which is approximately a half of our requirement, was obtained with NAB. Compared to NAB, NAB + RK generated lower impulse thrust. The success rate of ignition was as low as 30%, although RK was used. These results suggest that RK has no benefit for the ignition of NAB, and other kinds of ignition aid should be found.
A-10Gbit/s lightwave transport system over a-50km large effective area fiber (LEAF) tranmission based on vertical cavity surface emitting laser (VCSEL) and semiconductor optical amplifier (SOA) with external light injection technique is proposed and demonstrated. Improved bit error rate (BER) performance was observed under direct modulation of 10Gbit/s, attributed to the LEAF to reduce the total fiber dispersion and SOA light injection technique to suppress the SOA-induced distortion. This demonstrated lightwave transport system is very attractive for the 10Gbit/s backbone applications, which can inter-operate with high-speed optical communication networks.
We propose a high-performance inductor based on the concept of a high-impedance surface (or artificial magnetic conductor). The inductor is shielded from the silicon substrate by a high-impedance surface consisting of a lumped capacitor and inductor. Theoretical calculations comparing the proposed inductor with a conventional inductor shielded by an ordinary metal surface show that the resonant frequency and quality factor (Q) in the millimeter-wave region are higher for the proposed inductor.