Multimedia Signal Processors: An Architectural Platform with Algorithmic Compilation

Novel algorithmic features of multimedia applications and advances in VLSI technologies are driving forces behind the new multimedia signal processors. We propose an architecture platform which could provide high performance and flexibility, and would require less external I/O and memory access. It is comprised of array processors to be used as the hardware accelerator and RISC cores to be used as the basis of the programmable processor. It is a hierarchical and scalable architecture style which facilitates the hardware-software codesign of multimedia signal processing circuits and systems. While some control-intensive functions can be implemented using programmable CPUs, other computation-intensive functions can rely on hardware accelerators.To compile multimedia algorithms, we also present an operation placement and scheduling scheme suitable for the proposed architectural platform. Our scheme addresses data reusability and exploits local communication in order to avoid the memory/communication bandwidth bottleneck, which leads to faster program execution. Our method shows a promising performance: a linear speed-up of 16 times can be achieved for the block-matching motion estimation algorithm and the true motion tracking algorithm, which have formed many multimedia applications (e.g., MPEG-2 and MPEG-4).     

Low-voltage BiCMOS dynamic minimum circuit using a parallelcomparison algorithm for fuzzy controllers

The authors present a low-voltage BiCMOS dynamic minimum circuit using a parallel comparison algorithm for VLSI implementation of fuzzy controllers. Using low-voltage BiCMOS dynamic circuits and a parallel comparison algorithm, a four-4-bit-input minimum circuit designed, based on a 1μm BiCMOS technology, shows a 9.5ns comparison time, which is a ×2.5 improvement in speed as compared to that based on CMOS technology     

Molecular Orbital Calculations on 2, 4, 6-Trinitrotoluene

Three ab initio calculations (HF/6-3IG, HF/6-3IG*, and HF/6-3IG**) on 2,4,6-trinitrotoluene were made, The results compare well with xray data, except dihedral angles of NO₂ relative to the plane of the benzene ring. The deviations are attributed to packing forces and steric effects in the crystal. The most stable structure was a torsional angle 10° of the methyl top with the benzene ring, unlike toluene. The rotational barriers of the methyl top and the 4-nitro group are small. Hydrogen bonding, dipole moments and total atomic charges arc calculated.     

Broadcast digital subscriber lines

The adoption of asymmetrical digital subscriber lines (ADSL) technology in conjunction with the broadcast digital subscriber lines (BDSL) proposed in this paper could provide a cost effective solution for the introduction of digital video services in the near term. BDSL provides the same digital broadcast video programs to all subscribers through existing twisted pair telephone loops. In this paper, the basics of telephone loop-based digital subscriber lines are first discussed. Then the potential of BDSL is explored in the twisted pair loop plant near end crosstalk (NEXT), far end crosstalk (FEXT), and white noise environment. The capability of BDSL is examined with different serving areas and transmit power levels. The possibility of using orthogonal quadrature amplitude modulation (QAM) to implement a zero guard-band BDSL system is studied. Computer BDSL performance simulations are then presented. The combination of high-bit-rate digital subscriber lines (HDSL), ADSL, and BDSL can provide telephone subscribers many digital broadband services     

A soft switching active snubber optimized for IGBT's in singleswitch unity power factor three-phase diode rectifiers

This paper describes a soft switching active snubber for an IGBT operating in a single switch unity power factor three-phase diode rectifier. The soft switching snubber circuit provides zero-voltage turn-off for the main switch. The high turn-off losses of the IGBT due to current tailing are reduced by zero-voltage switching. This allows the circuit to be operated at very high switching frequencies with regulated DC output voltage, high quality input current and unity input power factor. Simulation and experimental results are included     

单片InGaAs／InP PIN PD阵列

文章简要地介绍了ＩｎＧａＡｓ／ＩｎＰ ＰＩＮ ＰＤ阵列的制作现状及其应用和发展趋势。     

Applications of ultrashort pulse propagation in Bragg gratings forwavelength-division multiplexing and code-division multiple access

We discuss theoretical and experimental studies on the propagation of ultrashort pulses through fiber Bragg gratings. We also consider several applications in optical communications to be found by combining ultrashort pulses and fiber Bragg gratings: a multiwavelength source for wavelength-division-multiplexed systems and a means for implementing optical code-division multiple access     

COIL中BHP浓度对发生O_2(~1△)的影响

本文实验研究了BHP的浓度对产生O2（1△）的影响。实验结果表明：当BHP浓度大于3.5M时，Cl2利用率以及O2（1△）的产率将不依赖于BHP浓度的变化而变化，同时，实验结果表明，使用低浓度的BHP对COIL的操作是可行的。     

红外热成象技术在股骨头坏死疾病针刺疗法中的应用

红外热成象技术可以有效地用于股骨头坏死疾病的诊断和针刺治疗效果的评价，效果优于其它常规方法。     

铜蒸汽激光器双闸流管触发系统的研究

研制成用于钢蒸汽激光器的双间流管触发系统。用两个闸流管并联进行交替触发，总输入电功率达7．8kW。低功率运行时，激光器的效率为0．6％与单间流管激光器的效率一致。