We propose a hardware operating system kernel (HOSK), which schedules tasks, controls semaphores, and pre-fetches contexts, as a hardware coprocessor in multiprocessor systems. A multiprocessor system can substantially reduce multithreading overheads by using the HOSK together with simplified RISC processors that do not include hardware for multithreading. We implemented an efficient HOSK which requires about 14 ∼ 25K gates. The experimental results show that the multithreading overheads with a HOSK can be reduced to less than 1 percent. Preliminary efforts confirm that this approach is a feasible solution for minimizing the hardware complexity of a multi-processor system.
The fitted parameters for the analytic function used to specify doping- and temperature-dependent low-field mobilities for In0.53Ga0.47As is described in this paper. The developed model was compared with other mobility models as well as measured Hall data from periodical literature and very good agreement is observed. The result of this work was used to develop an In0.53Ga0.47As interdigitated lateral p-i-n photodiode (ILPP) model and good correlation was obtained when compared with the experimentally developed device. The results of this work would be useful in the development of In0.53Ga0.47As-based devices using commercial device simulation packages.
A simple resistance-to-time converter is presented for interfacing resistive bridge sensors. It consists of two voltage comparators, a ramp voltage generator, and two logic gates. A prototype circuit built using discrete components exhibit a conversion sensitivity amounting to 2832.4µs/Ω over the resistance deviation range of 0-2Ω and a linearity error less than 0.005%. Power dissipation of the converter is 15.57mW.
To assist the diagnosis and analysis of heart disease, we introduce a template matching based method to detect the apical four-chamber (A4C) image plane in the three-dimensional echocardiographic (3DE) dataset. Firstly, a typical A4C image is selected as the template. Secondly, a series of cross-sections are extracted from a 3DE image. Finally, by a histogram-based retrieval, the cross-section most similar to the template is retrieved as the A4C image in this 3DE image. With low computational complexity and easy implementation, this method can detect the A4C image plane in 3DE images of different subjects by only one template image.
The computation burden and the huge memory size of the head-related transfer function (HRTF) database challenge the practical application of 3D sound system. This paper therefore proposes a novel method which employs principal components analysis and vector quantization jointly to reduce the size of HRTF set in 3D sound system. Numerical experiment results demonstrate that the proposed method can save the storage space greatly with little localization performance degradation.
Red and blue color purities and transmittances of transmissive display by MEMS (micro electro mechanical system) etalon (Fabry-Perot interferometer) have been greatly improved by changing reflecting electrode materials. 22% and 63% relative color purity deviation (CPD) reduction, and 27% and 255% transmittance improvement were achieved on red and blue pixels, respectively. The definition of relative CPD also provided a simple and fast way to judge two colors' purities from a target point on CIE 1931 Chromaticity Diagram without measurement of their luminance.
Direct measurements of propagation delay of single-flux-quantum (SFQ) circuits were performed using SFQ double-oscillator time-to-digital converters. The propagation delay of several SFQ logic gates in our cell library named CONNECT were measured in picosecond resolution. Small discrepancy in the propagation delay of picosecond level was observed between measurement and circuit simulation results. The discrepancy is well explained assuming the parasitic inductance around shunt resistors of Josephson junctions.
This paper describes novel small-area low-power regenerator to efficiently drive long on-chip dynamic interconnects. The proposed regenerator requires smaller device count, occupies smaller silicon area, adds less parasitic capacitance to the line, and consumes less power consumption with higher switching speed than conventional regenerators. Comparison results in a 0.18-um CMOS technology indicate that the proposed regenerator achieves up to 65% improvement on power-delay product with up to 56% reduction on silicon area.
This paper presents an efficient memory access interface architecture for H.264/AVC encoder. In the implementation of H.264/AVC encoder, the bandwidth compression of frame memory becomes a challenging issue due to some bandwidth intensive coding tools, such as multiple frames motion estimation, deblocking filter and INTRA mode decision. In this work, by analyzing the memory access patterns of each coding function module of H.264/AVC, an efficient memory access method for the Direct Memory Access (DMA) module is proposed. The proposed method carefully designed an efficient memory mapping method to decrease the memory response delay. Simulation results show that over 50% memory access cycles can be saved by using proposed method.
We propose a total-internal-reflection optical switch with a Bragg reflector waveguide. Slowing light in a Bragg reflector waveguide gives us an extremely large change in the equivalent refractive index of the waveguide, which is increased by a factor of more than 10 near a cut-off wavelength. Slowing light is caused by the giant waveguide dispersion of a Bragg reflector waveguide. The proposed structure enables a large bending angle of over 40 degrees even for reasonable refractive index changes of waveguide materials. The calculated result shows a possibility of large-scale and compact cross-bar waveguide optical switches.
Crosstalk repair by gate sizing often increases the noise on adjacent wires, and results in cyclical iterations of noise repair. We propose a Delayed Actively Body-bias Controlled (D-ABC) SOI scheme for crosstalk noise repair by providing delayed forward bias to drivers. The delay between gate and body suppresses the crosstalk noise on adjacent wires. The proposed D-ABC SOI scheme has reduced the crosstalk noise by 48.5%, with 4.3% increase in the crosstalk noise on adjacent wires.