This paper presents an asynchronous implementation of ARM9 processor, AEM32. We introduce an adaptive pipeline structure that makes the pipeline depth dynamically. We employ a parallel processing control based on datapath splitting to execute the instruction fed into the pipeline in parallel when they have different datapath. AEM32 is synthesized using a 0.35-µm CMOS cell library. Simulation results show that our implementation had 2.6 times higher performance than the asynchronous counterpart, AMULET3i. In terms of Et2, AEM32 shows 3 times higher efficiency than the other counterpart, ARM966HS.
The adjusting truncation-point strategy is applied to enhance the Rate-Distortion (R-D) embedding performance by rearranging the positions of truncation points which are associated with the refinement passes, with steepest rate distortion slope. Experimental results show that compared with JPEG2000 the proposed scheme reduces the number of not feasible truncation points to more than 50%, provides a finer embedded bitstream and achieves an improvement of PSNR ranging from 0dB to 0.10dB in a wide bitrate range.
A new architecture allowing an increase of the photocurrent of a photovoltaic cell fabricated with a CMOS 0.18µm process is described. This cell has been designed specifically to power the onboard electronics of a 400µm × 600µm untethered microrobot propelled by magnetotactic bacteria (MTB). Four cascaded cells of an area of 200µm × 200µm each, provide a short circuit current of 70µA and an open voltage of 0.48V from a 555nm 150 Watts commercial incandescent bulb. Experimental results show a power/area of the photocell of ∼ 110pW/µm2.
In this paper, we propose a new load impedance measurement system based on time-frequency domain reflectometry. The proposed system was able to measure the load impedances that were realized with using various terminal resistors and connected at the end of a cable. The experimental results show that the proposed system allows us to know where the connected terminal resistor is on the cable, and how much the impedance of the terminal resistor is. Through real experiments, it is possible for the proposed system to acquire more accurate results in wide range of impedance than conventional commercial time domain reflectometry instrument.
A novel hierarchical k-nearest neighbor classification method using the feature and observation space information is proposed. The present method performs a fine classification when a pair of the spatial coordinate of the observation data in the observation space and its corresponding feature vector in the feature space is provided.
As a new diluted magnetic semiconductor, vanadium-doped ZnSe is theoretically predicted to induce ferromagnetism above room temperature without carrier doping. Vanadium-doped ZnSe was epitaxially grown on (100) GaAs substrate by metal-organic vapor phase epitaxial method in an atmospheric pressure. As a dopant source of vanadium, triethoxyvanadyl was used. The influences of molar supply ratio of dimethylzinc to dimethylselenide on crystallinity were investigated in order to research the optimum vanadium-doping condition. The crystal growth condition of vanadium-doped ZnSe changed from epitaxial growth to polycrystal growth at molar supply ratio between 1.2 and 1.5.