Brain potentials after clicking a mouse: a new psychophysiological approach to human-computer interaction

As a first step in developing a new psychophysiological technique to assess mental workload in human-computer interaction (HCI), we recorded event-related brain potentials for visual stimuli triggered by voluntary mouse clicks. Twelve university students clicked a mouse button at their own pace. Each click triggered 1 of 3 alphabetic letters assigned to frequent standard, rare target, and rare nontarget stimuli. Counting target stimuli was required. Both rare stimuli elicited a P3 (P300) wave, the amplitude of which was larger when the stimuli were triggered by mouse clicks than when the same stimuli were presented automatically without mouse clicks. Postmotor potentials associated with clicking were small in amplitude (<2 microV) and did not temporally overlap with the P3. The findings suggest that the P3 can be recorded for a computer's response to the user's intentional action and may be used as a measure of perceptual-central processing resources allocated to the HCI task. Actual or potential applications of this research include the evaluation of the user's attentional state during HCI byrecording brain potentials in the "mouse click" or action-perception paradigm.     

Preparation and characterization of Ni-C composite films

Ni-C composite films were prepared using a codeposition method, their structure and electrical properties were investigated. Depending on experimental conditions, two typical structures are found for as-deposited Ni-C films: i) amorphous Ni-C alloy film; ii) granular film with Ni₃C granules and inter-granule amorphous carbon. The amorphous Ni-C films show ohmic conduction behaviour with very high resistivity. On the other hand, granular films with high carbon content show semiconductive characteristics. The electrical property and conduction behaviour are correlated with the film structure. Besides, the crystallization behaviour of the amorphous Ni-C film was also studied.     

A new self-alignment technology using bridged base electrode forsmall-scaled AlGaAs/GaAs HBT's

The fabrication and characterization of a new self-aligned HBT utilizing bridged base-electrode technology (BBT) are presented. This new technology simplifies the fabrication process and relaxes the limitations in device size scaling, thus decreasing the emitter size to 1 μm×1 μm. In spite of a large junction periphery area ratio, a good current gain of more than 10 is obtained in an HBT with an emitter size of 1 μm×1 μm. A series of fabricated HBTs shows excellent high-speed performance. The highest values of f_T =90 GHz and f_max=63 GHz are obtained in an HBT with an emitter size of 1 μm×5 μm. The realization of HBTs with small emitters and excellent high-frequency characteristics demonstrates the effectiveness of this new technology     

Electrochemical characterization of the electrical deposition of Co and properties of deposited films using amorphous ribbons as substrate

Both nonelectrically deposited Co‐P and Co‐Fe‐B and electrically deposited Co films were prepared on rapid‐quenched amorphous alloy ribbons. These Co‐based alloy deposits exhibited characteristic polycrystalline structures, surface morphology, and magnetic properties, which were dependent on the species of the amorphous substrates. The electrochemical polarization measurements of substrate electrodes revealed that the electrocatalysis of substrates (e.g., for the anodic oxidation of reducing agent) thoroughly interpreted the deposition potential and the rate of nonelectrical deposition, and the overpotential of electrical deposition were dependent on alloy element of substrate. These electrochemical parameters influence the initial step of deposition, and hence determine the structural and magnetic properties of the deposits obtained. Furthermore, a basic study of the electrical deposition processes on an amorphous ribbon substrate has been carried out in connection with the structural and magnetic properties of the deposits. © 2000 Scripta Technica, Electr Eng Jpn, 130(4): 17–25, 2000     

Improved AlGaAs/GaAs HBT performance by InGaAs emitter cap layer

The effects of the emitter resistance reduction on the DC and high-frequency characteristics in an AIGaAs/GaAs HBT with an InGaAs emitter cap layer are investigated. In fabricated devices, a transconductance per unit area of 16mS/?m2 and a cutoff frequency of 80 GHz have been achieved.     

22 GHz 1/4 frequency divider using AlGaAs/GaAs HBTs

A divide-by-four frequency divider using AIGaAs/GaAs HBTs with GalnAs/GaAs emitter cap layers was designed and fabricated. A maximum toggle frequency of 22.15 GHz was obtained at a power supply voltage of 9 V and a total power dissipation of 712 mW. The minimum input signal power was under 0dBm and the free-running frequency was as high as 20 GHz.     

A new self-aligned AlGaAs/GaAs HBT based on refractory emitter andbase electrodes

A self-alignment technique for AlGaAs/GaAs heterojunction bipolar transistors (HBTs) using refractory metal film, W, as the emitter and base electrodes is presented. A nonalloyed contact formation combined with selective reactive ion etching of W or WSi_x against GaAs and SiO₂ produces a self-aligned structure. An emitter contact that is thermally stable is obtained by using a Zn diffusion process to make the extrinsic base contact layer. An f_T value as high as 82 GHz was obtained. The self-alignment technique combined with the Zn diffusion process will achieve a much higher f_T if a thinner base HBT structure is used     

奥氏体不锈钢的高频离子氮化

本文介绍一种只用高频产生等离子体的氮化方法(简称高频离子氮化法)。找出比较合适的氮-氢气体比例及合适气压、温度的氮化工艺参数。获得高的表面硬度(HV 1575左右)和较厚的氮化层(85μm)。初步分析了影响氮化层性质的一些因素。     

Self-aligned AlGaAs/GaAs HBT with InGaAs emitter cap layer

A new self-aligned AlGaAs/GaAs HBT with an InGaAs emitter cap layer is presented. This HBT has nonalloyed ohmic contacts to the emitter and base that are formed simultaneously and in a self-aligned manner. The low emitter contact resistance of 1.4×10-7 ?cm2 and the high transconductance per unit area of 3.3 mS/?m2 demonstrate the effectiveness of this structure.