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Blu-ray disc (BD)/digital versatile disc (DVD)/compact disc (CD) compatible optical pickup supporting Blu-ray 4times read/write has been developed. To achieve 4times speed for BD, a one-lens-type objective lens was adopted to ensure stability for high-speed tracking servo control. Optical system, signal characteristics, and actuator vibration characteristics of the developed pickup are presented.

There has been a considerable amount of research done into the detection and evaluation of human emotions from implicit communication channels, including facial expressions. However, most studies have extracted facial features for some specific emotions in specific situations. This paper describes a real time emotion diagnosis system, which can judge the emotions of a video game player from his/her facial expression and navigate him/her by voice feed-backing messages. Criteria for classifying six emotions were established using a time sequential subjective evaluation of the subject's emotions as well as the time sequential analysis of the subject's facial expressions. A voice feed-back system for game players was constructed by using the above mentioned emotion criteria, emotion diagnosis algorithm and synthesized voice generation software.

There has been a considerable amount of research done into the detection and evaluation of human emotions from implicit communication channels, including facial expressions. However, most studies have extracted facial features for some specific emotions in specific situations. This paper describes a system which can judge the emotions of an e-Learning user from his/her facial expression and biometrical signals. Criteria for classifying eight emotions were established using a time sequential subjective evaluation of the subject’s emotions as well as the time sequential analysis of the subject’s facial expressions and biometrical signals. The coincidence ratio between the discriminated emotions based upon the criteria of emotion diagnosis and the time sequential subjective evaluation of emotions for 10 e-Learning subjects was 74%. When only the facial expressions were taken into account, the coincidence ratio was 68%. These results confirm the effectiveness of the multi-modal emotion diagnosis.

Achromatic 180° -phase shift is demonstrated to null the polychromatic light emitted from on axial direction in order to detect the light emitted from off-axial source. Nulling of the polychromatic light over 300 nm bandwidth is shown by simple experiment.

A novel CoWP cap integration technology for lower leakage current and improved dielectric reliability is proposed for porous low-k/Cu interconnects, NH3 plasma treatment before SiCN deposition reduces leakage current and improves dielectric reliability such as time-dependent dielectric break-down (TDDB) of CoWP capped Cu interconnects. The TDDB lifetime much longer than 10 years is obtained. Moreover, the leakage current less than IE-14A/mm is obtained by low-k top (LKT) dielectric structure combined with the NH3 plasma treatment. In addition, 10% lower RC product is obtained by the LKT structure with CoWP cap

There have been a lot of researches on the detection/estimation of human emotions from facial expressions. However, most of them have extracted facial features for some specific emotions from the still pictures of artificial actions or performances. This paper describes facial tracking for e-learning support robot which can estimate a emotion of e-learning user from his/her facial expression in real-time; (1) the criteria of the facial expression to classify the eight emotions was obtained by the time sequential subjective evaluation on the emotions as well as the time sequential analysis of a facial expression by image processing. (2) The coincidence ratio between the discriminated emotions based upon the criteria of emotion diagnosis and the time sequential subjective evaluation on emotions for ten e-learning subjects was 69%. (3) Then, the possibility of the real time emotion diagnosis robot to support e-learning was confirmed by the facial image processing at the 15 frame/sec. rate as well as the simple emotion diagnosis algorithm based upon the Mahalonobis distance

A novel resistivity measurement technique has been proposed for scaled-down Cu interconnects viewing the high-reliability automobile applications. This technique enables to detect the interconnect resistivity dependence on impurity concentration, free from dimension dependence. Using this technique, we investigated impacts of impurity concentration on three types of Cu interconnects: 1) CoWP cap; 2) PECVD self-aligned barrier (PSAB); and 3) CuAl interconnects and clarified the tradeoffs between resistivity and reliability. We have found that CoWP cap shows not only high-reliability but also an outstanding efficiency in suppression of resistance increase due to impurity-induced scattering, indicating that it is the most viable candidate for automobile applications in 32nm generation and beyond

This paper presents an analysis of roundoff error accumulation in the direct realization of a logarithmic-arithmetic digital filter and formulas for computing the ratio of the rms value of the roundoff error and that of the output signal of the digital filter. It is shown that for the case of the stochastic input, the theoretical error to signal ratio is less using logarithmic number systems as compared to using floating-point number systems. The theoretical results of the roundoff error analysis were verified in simulation experi ments. The experimental results also show that the logarithmic number system gives filtering performance superior to that of a floating-point system of equivalent word length and range and that the limitation in implementing digital filters with logarithmic number system is a function of the range of the numbers which may be represented.

A new structure InGaAs/InP MQW bistable laser-diode with a sub-waveguide for light injection is demonstrated. Very small sensitivity dependence on input light wavelength (28 nm of 3 dB bandwidth) and high isolation of input versus output ( over 30 dB) are observed.

A parallel algorithm for the n-task-n-person assignment problem is presented in this paper. The proposed algorithm is based on the artificial neural network model where a large number of simple processing elements are used. Through a large number of simulation runs, it was empirically shown that the state of the system can converge to the solution within a hundred iteration steps regardless of the problem size n. The proposed algorithm using n/sup 2/ processing elements requires computational bounds of a nearly O(1) time.

Many optical interconnection technologies have been proposed, most of which can be broadly classified as either guided-wave or free-space type optics. Guided-wave optic interconnections using optical fibers or waveguides can be practically implemented because they match with conventional fiber-optic transmission technology. By contrast, free-space optic interconnections can carry large amounts of data in the form of two-dimensional optical patterns, though they are more difficult to integrate. In this paper, we propose a new class of optical interconnections, in which a two-dimensional optical pattern is directly transmitted through a multimode fiber or waveguide. It could offer both the advantages of the flexiblity of guided-wave optics and the massive parallelism of free-space optics. Although direct image transmission utilizing phase conjugation has been proposed', a viable implementation has yet to be realized because of the practical difficulty of preparing two identical fibers for transmission. However, use of a phase conjugation mirror (PCM) with an image-input function enables guided-wave optic interconnection for optical patterns, as shown in Fig. 1. With this approach, reference and object light from the receiver site are conveyed to the transmitter through a single-mode and a multimode waveguide, respectively. When the reference beam is perpendicularly incident on the PCM, the conjugated wave is reflected and transmitted back through the multimode waveguide. When an interference pattern on the PCM is modulated by the optical data pattern, the optical pattern input on the PCM can be reconstructed at the receiver site through an imaging lens because the phase distortion of returned beam through the multimode waveguide is compensated. . The interconnection proposed above has been experimentally demonstrated using a multimode fiber (1 mm in diameter by 200 mm in length) and an optically-addressed spatial light modulator (SLM). The SLM2, consisting of an a-Si:H photoconductor and a ferroelectric liquid crystal (FLC), acts as a PCM with an image-input function. Two coherent beams from a He-Ne laser were incident on the photoconductor via the FLC to record the interference pattern3. The optical pattern to be transmitted was focused on the photoconductor with another incoherent light source. The pattern illumination modulated the interference pattern on the SLM since the interference pattern were erased in the illuminated regions. One result of the experiment is shown in Fig. 2. The intensities of the coherent beams and data illumination light are 0.5 mW/cm*. This interconnection technology could also be applied for reconfigurable interconnection among processors and memories, where parallel access to optical storage would support a huge throughput capacity4. Switchable parallel access from two receiver sites to the same optical data has been demonstrated, as shown in Fig. 3. A He-Ne laser beam is split into three beams. One is a reference beam, and the others are object beams which are separately sent to the SLM through a fiber and a shutter. Two shutters (Sl,S2) are placed in the path of each object beam for access switching. Experimental results are shown in Fig. 4., where the optical data were readout by CCD sensor configured for each fiber. And the same data pattern was also readout by both sensors simultaneously. The significant implication is that multiple processors can access the same memory in parallel at the same time. In conclusion, we have proposed a guided-wave optic interconnection for optical patterns that uses a spatial light modulator which acts as a phase conjugation mirror with an image-input function. This technology could have a wide range of applications, including parallel access to optical memories from multiple processors.

A new on-line identification method of suspension force and magnetic unbalance pull force parameters in buried-type IPM bearingless motors has been presented in this paper. The suspension force parameters depend on the current condition, because armature reaction and magnetic saturation in the stator teeth often occur in this type of machines. Moreover, the magnetic unbalance pull force also generates due to the small airgap, which are also dependent on the current. Thus, it is necessary that these parameters are accurately identified so that the rotor shaft is stably supported. An on-line parameter identification method has been proposed. It is possible that the parameters are accurately identified by a simple experiment. It is confirmed that the suspension force decoupling tests accurately identifies the parameters. The obtained parameters by the proposed method are compared with the FEM results and discussed. The proposed on-line identification method is good enough to realize stable magnetic suspension

Copper (Cu) damascene interconnects with a cobalt tungsten phosphorus (CoWP) capping layer were developed using an alkaline-metal-free electrodes plating process without palladium (Pd) catalyst activation. The wafer contamination level after processing is consistent with requirements for present LSI fabrication lines. Within wafer CoWP deposition uniformity is high and interconnects wire resistance increases by less than 5% after deposition. Electromigration (EM) testing shows no failures after two thousand hours and stress induced voiding (SIV) testing shows no failure after three thousand hours. This EM result is a 2 order or magnitude improvement over a non CoWP process.

As a basic study of a fiber optic power transmission system, characteristics of a photovoltaic (PV) cell for high-intensity laser light were investigated. The energy conversion efficiency much higher than that for solar light was experimentally confirmed. As a degradation factor of the energy conversion efficiency of the PV cell, the effect of the heat caused by the laser was clarified. We showed that a heat radiator could effectively suppress the temperature increase and maintain the high conversion efficiency. We also clarified that the minute value of series resistance of the PV cell could degrade the PV cell characteristics.

We demonstrate, for the first time, optical response of a side-injection light-controlled bistable laser diode (SILC-BLD) buried with semi-insulating InP using hydride vapor phase epitaxy (HVPE). The buried surface around both the and oriented mesas is flat. The bistable operation is obtained by applying control voltage to the saturable absorption region. The modulation bandwidth, f/sub 3dB/, for the injected optical signal is over 3.5 GHz.

Smart pixels incorporating vertical-cavity surface-emitting lasers (VCSELs) have shown great potential for use in optical computing systems and photonic switching networks because the integration of the VCSEL makes optical circuits easy to construct. We have developed integration with a VCSEL, MESFETs, and a metal-semiconductor-metal (MSM) photodetector. In this device, both NOR- and OR-types of operation can be performed with the same circuit. The device operated at a high contrast ratio of more than 30 dB with optical gain. It also showed the 3-dB bandwidth of 220 MHz with 300-/spl mu/W input power. We recently proposed a novel structure that uses three-dimensional integration of the compound semiconductor thin-film and a silicon circuit. The VCSEL and photodetector layers are bonded onto a silicon circuit using polyimide. This method does not require any alignment before wafer bonding. The fabrication process for the photonic circuit is the same technology that is used in our monolithic integrated smart pixel, so it facilitates a wafer-scale fabrication process. To demonstrate this technology, we fabricated an MSM photodetector on a silicon substrate.

Calculation of the electric field induced into an inhomogeneous medium by time-varying magnetic fields is very complicated. Therefore results of magnetic nerve stimulation are not always predictable. Previously proposed inhomogeneous models composed of a nonconducting medium and an electrolyte solution are appropriate only for nerves adjacent to bony structures. In this report, the authors propose a new inhomogeneous model which is appropriate for nerves far from bone. The model consists of double troughs. The outside and inside troughs are filled with saline solutions of 0.1% and 0.9%, respectively. The electric fields induced into this model by a figure-eight coil are measured, and its first spatial derivatives are calculated. Unlike those induced into a homogeneous model, they shift towards a 0.9% solution.

Summary form only given. Digital optical signal regeneration with a SILC-BLD markedly improves the bit error rate of the degraded optical signals. The diode cannot only regenerates the signal but also converts the signal wavelength at the same time without wavelength filters and isolators.

Digital free-space photonic switches that digitally regenerate optical signals at each stage are suitable for constructing a compact large-scale switching fabric. In a previous report, we demonstrated a single-stage, two-input, two-output, digital free-space photonic switch that uses an exciton absorption reflection switch (EARS). It provides optically controllable switching with optical signal regeneration. In this paper, we present the experimental results for a two-stage digital free-space photonic switch that uses cascaded EARS arrays and relay lens optics. The relay lens optics provides the low loss coupling between EARS arrays necessary for high-speed switching.

Stable polarized light emission from VCSELs grown on [311]B substrates by MOCVD has been achieved under CW and dynamic operations, in contrast with VCSELs on [100] substrates. A polarization extinction ratio of 9 dB under zero-biased modulation was obtained. The fabricated VCSELs consisted of Si-doped DBR, three GaAs/AlGaAs quantum well active region sandwiched between one-wavelength thick AlGaAs spacer layers, and a C-doped DBR.

This report describes a 1.3-/spl mu/m surface-normal asymmetric Fabry-Perot modulator using the Wannier-Stark effect of an InP/InGaAsP superlattice. The extinction ratio of 11.6 dB is achieved at 14 V. The insertion loss is 9.9 dB. This is the first time an extinction ratio of over 10 dB has been obtained in surface-normal optical modulators operating at 1.3 /spl mu/m.

In the development of advanced information systems, such as parallel processing computers and ATM switching systems, the speed and capacity of board-mountable processors and switches will increase considerably through advances in VLSI technology. VCSEL based smart pixels will be the key devices to interconnect the VLSI chips, with high throughput at both the inter- and intra-board level. The technical issues involved in applying VCSEL based smart pixels to parallel optical interconnection systems are discussed from the viewpoint of their system applications.

The differences of muscle responses to magnetic nerve stimulation with different coil current waveforms were predicted using cable theory and investigated on the median nerve in a human subject. The mono- and biphasic coil current whose time derivatives were bi- and triphasic with the equivalent 1st phase were compared concerning (1) the excitation threshold, (2) latency and (3) amplitude of compound muscle action potentials (CMAPs). The effect of different coil current directions, proximal or distal, at the intersection of a figure-eight coil were also considered. The combinations of the coil current waveforms and directions were termed MONO-PROX, MONO-DIST, BI-PROX and BI-DIST, where MONO- and BI-corresponded to monophasic and biphasic, and PROX and DIST to proximal and distal, respectively. The results in man were that (1) the excitation threshold was the lowest with BI-DTST, (2) the latencies with MONO-PROX and BI-PROX were equivalent to each other, and (3) the amplitudes of CMAPs with BIPROX and BI-DIST were almost equivalent and larger than with the others. The results in man were generally consistent with predictions, except for the evaluation of "cathode distal" effect.

We investigated the possibility of selective stimulation of cervical nerve roots in healthy subjects. The skin surface on the anterior neck was divided into 12 portions of 2 cm/spl times/2 cm each. Each portion was stimulated magnetically with a figure-eight coil. Induced eddy currents were downward. M-waves of the infraspinatus, the deltoid, the biceps brachii, the triceps brachii, the extensor digitorum communis, the flexor carpi ulnaris, the abductor pollicis brevis, and the abductor digiti minimi were monitored. The stimulation of some specific portions evoked M-waves of only the infraspinatus and the deltoid. The infraspinatus and the deltoid are innervated predominantly by the 5th cervical nerve, so these results suggest that the 5th cervical nerve root was selectively stimulated with a figure-eight coil.

This paper describes a smart recognition system which performs character matching by replacing speech parameters with the five Japanese vowels and a few consonant categories. The proposed algorithm can make speaker-independent voice recognition. The algorithm has an advantage over the conventional speaker-independent word recognition system because it can reduce the required memory to about 0.5% of the conventional algorithm for storing the reference templates and for the instruction set, and can be performed even in a low-speed processor. We implemented this recognition algorithm in a fixed-point, 20 MIPS digital signal processor board with a 9-k/spl times/16-bit on-chip RAM. Recognition experiments using 20 Japanese city names had a 90.3% accuracy. Such an accuracy is good enough for a voice control system.

Summary form only given. In future communication systems with more than a 100 Gbit/s data rate, all-optical signal processing will be important. We have proposed a time-space-conversion optical signal processing that uses an arrayed waveguide grating (AWG) and demonstrated pulse train generation using an amplitude filter. The AWG system can provide a wide time window, compatibility with fiber optics, and compactness. In this study, we report the differential processing of short pulses using AWG with a phase-only filter in order to test the feasibility of extending the AWG system to ultra-high-speed communication.

The paper proposes a new fault tolerant communication scheme for real-time operations and three new interconnection networks to construct a fault tolerant multi-processor system for pipeline processings. The proposed communication scheme using bank memory switching technique has an advantage to make a fault tolerant pipeline system so that it can detect any failure caused in a processing element of the system. In addition, it can overcome conventional problems caused in interconnection circuits to data flow with one direction such as a pipeline processing. >

The oil-filled pressure-compensated Silver-Zinc Battery System was developed and applied for practical use as a power source of the 2,000m Deep Submergence Research Vehicle"SHINKAI 2000"(DSV-2K). The battery system is made up of 2 main units, each consisting of 72 cells. After successful tests on cells and one main unit, the battery system practically used in the DSV-2K served satisfactorily for almost one year under the no-maintenance conditions and showed the good performance as was expected. The structure, designe considerations and test results are summarized hereunder.