Showing papers by "Mitsubishi Electric published in 2004"

Robust Real-Time Face Detection

Abstract: This paper describes a face detection framework that is capable of processing images extremely rapidly while achieving high detection rates. There are three key contributions. The first is the introduction of a new image representation called the “Integral Image” which allows the features used by our detector to be computed very quickly. The second is a simple and efficient classifier which is built using the AdaBoost learning algorithm (Freund and Schapire, 1995) to select a small number of critical visual features from a very large set of potential features. The third contribution is a method for combining classifiers in a “cascade” which allows background regions of the image to be quickly discarded while spending more computation on promising face-like regions. A set of experiments in the domain of face detection is presented. The system yields face detection performance comparable to the best previous systems (Sung and Poggio, 1998; Rowley et al., 1998; Schneiderman and Kanade, 2000; Roth et al., 2000). Implemented on a conventional desktop, face detection proceeds at 15 frames per second.

Thermal annealing effects on Ni/Au based Schottky contacts on n-GaN and AlGaN/GaN with insertion of high work function metal

Abstract: Recent progress in GaN based high electron mobility transistors (HEMTs) has revealed them to be strong candidates for future high power devices with high frequency operation. In order to extract and utilize the favorable GaN material properties, however, there is still a lot to be investigated. Reduction of the gate leakage current is one of the key issues to be solved for their further improvement. A high work function metal such as Pt, Ir, Pd or Mo was inserted to the conventional Ni/Au Schottky contact to n-GaN and AlGaN/GaN epilayers, and the Schottky diodes were studied in detail with respect to the thermal annealing in nitrogen ambient. The electrical characteristics were found to be changed by the thermal treatment in each device. A drastic improvement was attained in the Ni/Pt(Ir)/Au system whereas degradation occurred in Ni/Mo/Au by RTA at 500 °C for 5 min. These phenomena were confirmed to be dependent on the work function of each inserted metal. The role of Ni in the Ni/Pt/Au system was also investigated, and it was found to be essential in obtaining better electrical performance in comparison with the diodes without Ni, such as Pt/Au or Ir/Au Schottky electrodes. The AlGaN/GaN HEMTs were fabricated using Ni/Pt/Au gate contacts. Reduction of the gate leakage current by as much as four orders of magnitude was successfully recorded by thermal annealing without degrading the transconductance of the transistor, and it was concluded that this technique was promising for high power AlGaN/GaN HEMT electronics.

3D television system and method

Abstract: A three-dimensional television system includes an acquisition stage, a display stage and a transmission network. The acquisition stage includes multiple video cameras configured to acquire input videos of a dynamically changing scene in real-time. The display stage includes a three-dimensional display unit configured to concurrently display output videos generated from the input videos. The transmission network connects the acquisition stage to the display stage.

Likelihood-maximizing beamforming for robust hands-free speech recognition

Abstract: Speech recognition performance degrades significantly in distant-talking environments, where the speech signals can be severely distorted by additive noise and reverberation. In such environments, the use of microphone arrays has been proposed as a means of improving the quality of captured speech signals. Currently, microphone-array-based speech recognition is performed in two independent stages: array processing and then recognition. Array processing algorithms, designed for signal enhancement, are applied in order to reduce the distortion in the speech waveform prior to feature extraction and recognition. This approach assumes that improving the quality of the speech waveform will necessarily result in improved recognition performance and ignores the manner in which speech recognition systems operate. In this paper a new approach to microphone-array processing is proposed in which the goal of the array processing is not to generate an enhanced output waveform but rather to generate a sequence of features which maximizes the likelihood of generating the correct hypothesis. In this approach, called likelihood-maximizing beamforming, information from the speech recognition system itself is used to optimize a filter-and-sum beamformer. Speech recognition experiments performed in a real distant-talking environment confirm the efficacy of the proposed approach.

A study on eddy-current losses in rotors of surface permanent magnet synchronous machines

Abstract: In this paper, we investigate the Eddy current (EC) losses in the rotors of surface permanent-magnet (PM) synchronous machines, which have concentrated armature windings. By the finite-element method (FEM) analysis, it is clear that the EC losses in rotors are apparently different at rated currents if the pole and slot combinations are different. The distribution of the EC density in the rotor is closely related with the asynchronous components of the armature magnetomotive force (MMF). If the armature MMF has a low order of spatial harmonic components, which is not synchronous with the rotor, the EC losses are of large amounts.

43.3: Summary of Moving Picture Response Time (MPRT) and Futures

Abstract: Moving Picture Response Time (MPRT) measurement method has discussed with several companies since 2001. The basic MPRT is designed to represent and quantify the visual perception of moving images across an AM-LCD screen for PC monitor and TV applications. MPRT measurement method takes into account three basic LCD panel characteristics: the capacitive-hold-type brightness variations, brightness level dependent transition times and a liquid crystal response time including gray scales transition. This measurement system incorporates the synchronously moving some combined gray scale test patterns and the evaluation of the pattern edge brightness changes. MPRT keyword is for only liquid crystal display. But this measurement method can be used to specify new index parameter that is motion blur characteristics on each display devices (PDP, CRT and etc).

Power amplifier unit, communication terminal and control method of power amplifier unit

Abstract: A power amplifier unit having a power amplifier which can be used efficiently without causing any trouble in operation. A control section (11) makes a decision based on an estimated output power level whether the power amplifier is in a first period performing low power output operation or in a second period performing high power output operation. During the first period, a DC/DC converter (2) is brought into active state and a power supply voltage Vdd2 is supplied as the operating power supply voltage of an HPA (1). During the second period, activation/inactivation of the DC/DC converter (2) and on/off of a switch (3) are controlled based on a power supply voltage level VM detected by an operating power supply voltage detecting circuit (13) and one of the power supply voltage Vdd2 or a power supply voltage Vdd3 is supplied as the operating power supply voltage.

21.5-dBm power-handling 5-GHz transmit/receive CMOS switch realized by voltage division effect of stacked transistor configuration with depletion-layer-extended transistors (DETs)

Abstract: This paper reports a 21.5-dBm power-handling 5-GHz transmit/receive CMOS switch utilizing the depletion-layer-extended transistor (DET), which possesses high effective substrate resistance and enables the voltage division effect of the stacked transistor configuration to work in the CMOS switch. Furthermore, low insertion losses of 0.95 and 1.44 dB are accomplished at 5 GHz in the transmit and receive modes, respectively, with the benefit of the insertion-loss improvement effects in the DET. At the same time, high isolations of more than 22 dB were obtained at 5 GHz in the transmit and receive modes with the adoption of the shunt/series type circuit.

Dual-band-rejection filter for distortion reduction in RF transmitters

Abstract: A novel concept of dual-band-rejection filter (DBRF) is proposed with its circuit synthesis procedure and examples of its realization with dielectric resonators and microstrip resonators. A DBRF can make two closely spaced rejection bands and a passband between them, with lower loss than a bandpass filter having the same number of resonators and the same frequency selectivity just around the passband. The DBRF can be synthesized by applying novel frequency-variable transformations to a prototype LPF, and its physical size can be smaller than a simple cascade of two conventional band-rejection filters with different rejection bands. The DBRF can be especially applicable to distortion reduction filter in RF transmitters.

Exploiting Depth Discontinuities for Vision-Based Fingerspelling Recognition

Abstract: We present a novel method for automatic fingerspelling recognition which is able to discriminate complex hand configurations with high amounts of finger occlusions. Such a scenario, while common in most fingerspelling alphabets, presents a challenge for vision methods due to the low intensity variation along important shape edges in the hand image. Our approach is based on a simple and cheap modification of the capture setup: a multi-flash camera is used with flashes strategically positioned to cast shadows along depth discontinuities in the scene, allowing efficient and accurate hand shape extraction. We then use a shift and scale invariant shape descriptor for fingerspelling recognition, demonstrating great improvement over methods that rely on features acquired by traditional edge detection and segmentation algorithms.

Deployable antenna with 10-m maximum diameter for space use

Abstract: This paper describes a large deployable antenna which is used at L-, C-, and Ka-bands on an artificial satellite in space. The main reflector with 10-m maximum diameter is formed using the tensioned truss concept which was proposed by one of the authors. The mechanical structure of the antenna is briefly explained and a more detailed description given of the electrical design of the antenna and the verification method of electrical characteristics. This antenna was successfully launched and deployed in space in 1997 and is used for a Space VLBI mission.

Bilarge neutrino mixing and μ − τ permutation symmetry for two-loop radiative mechanism

Abstract: The presence of approximate electron number conservation and $\ensuremath{\mu}\ensuremath{-}\ensuremath{\tau}$ permutation symmetry of ${S}_{2}$ is shown to naturally provide bilarge neutrino mixing. First, the bimaximal neutrino mixing together with ${U}_{e3}=0$ is guaranteed to appear owing to ${S}_{2},$ and then, the bilarge neutrino mixing together with $|{U}_{e3}|\ensuremath{\ll}1$ arises as a result of a tiny violation of ${S}_{2}.$ The observed mass hierarchy of $\ensuremath{\Delta}{m}_{\ensuremath{\bigodot}}^{2}$ $\ensuremath{\ll}$ $\ensuremath{\Delta}{m}_{\mathrm{atm}}^{2}$ is subject to another tiny violation of the electron number conservation. This scenario is realized in a specific model based on ${\mathrm{SU}(3)}_{L}\ifmmode\times\else\texttimes\fi{}{U(1)}_{N}$ with two-loop radiative mechanism for neutrino masses. The radiative effects from heavy leptons contained in lepton triplets generate the bimaximal structure, and those from charged leptons, which break ${S}_{2},$ generate the bilarge structure together with $|{U}_{e3}|\ensuremath{\ll}1.$ To suppress dangerous flavor-changing neutral current interactions due to Higgs exchanges especially for quarks, this ${S}_{2}$ symmetry is extended to a discrete ${Z}_{8}$ symmetry, which also ensures the absence of a one-loop radiative mechanism.

Retransmission control method and communications device

Abstract: A retransmission control method comprising: generating N parity check matrices; generating a generator matrix containing a check symbol generator matrix contained in the first parity check matrix; transmitting the codeword generated by using the generator matrix to another communications device; generating, when the communications device receives a NAK in response to the codeword, a first additional parity by using the second parity check matrix; and retransmitting the first additional parity to the another communications device

Motor control apparatus

Abstract: A motor control apparatus capable of protecting a motor from overheat while changing smoothly a motor output characteristic as a function of time lapse and mitigating overhead involved in arithmetic operation includes a current command value generator for generating current command values for a motor ( 1 ) having a polyphase winding, and motor current value detecting circuits ( 3 u, 3 v ) for detecting motor current values (iu, iv), to drive the motor ( 1 ) on the basis of the motor current values and current command values The apparatus further includes a PWM inverter ( 4 ) for driving the motor ( 1 ) and a microcontroller ( 5 ) for controlling the PWM inverter ( 4 ) The microcontroller ( 5 ) limits the motor current values in dependence on integrated values of function values determined by fitting transformed current values determined through predetermined coordinate transformation of the phase currents (iu, iv, iw) to a predetermined function

Effects of a Novel Gaseous Antioxidative System Containing a Rosemary Extract on the Oxidation Induced by Nitrogen Dioxide and Ultraviolet Radiation

Abstract: Rosemary is commonly used as a spice and a flavoring agent in food processing. Although the antioxidative properties of its extracts have been investigated, there have been few reports on the volatile components of rosemary. We designed a novel antioxidative system which can generate the volatile constituents in the gaseous phase from a rosemary extract and evaluated the gaseous antioxidative activities against both lipid peroxidation and cell death induced by nitrogen dioxide and ultraviolet radiation. The antioxidative effects of the major volatile components on the oxidation of linoleic acid induced by azo compounds were also investigated in a solution. The volatile components in the novel antioxidative system suppressed the Jurkat cell death induced by nitrogen dioxide and the intracellular formation of reactive oxygen species in fibroblast cells induced by ultraviolet radiation. 1,8-Cineole among the volatile components exerted an antioxidative effect against the oxidation of linoleic acid in a solution induced by azo compounds and ultraviolet radiation. These data suggest that the volatile constituents of a rosemary extract had antioxidative properties and that gaseous exposure antioxidant is a promising method for promoting health.

Distortion compensating apparatus

Abstract: A distortion compensating apparatus comprising an IQ unbalance compensation efficient calculation part (31) for calculating, from the correlation value between a transmitted signal and a feedback signal, an IQ unbalance compensation efficient with which to compensate the IQ unbalance in a quadrature modulation part (23); and an IQ unbalance compensation part (21) for compensating, by use of the IQ unbalance compensation efficient, the IQ unbalance of a distortion-compensated signal, which is outputted by a distortion compensation part (11), to output the IQ unbalance compensated signal to the quadrature modulation part (23).

Base station, mobile communication terminal equipment, and primary cell determination method

Abstract: A base station receives a signal transmitted from a mobile station, estimates the state of the radio uplink, and receives state information indicating the state of the radio downlink measured by the mobile station. When the uplink quality and the downlink quality satisfy scheduling grant conditions set up in advance, the base station is allowed to carry out scheduling for the mobile station. In contrast, the base station is not allowed to carry out the scheduling for any terminal in which a link imbalance has occurred. Therefore, the throughput of the whole system increases.

Stereoscopic image display device

Abstract: PROBLEM TO BE SOLVED: To provide a stereoscopic image display which prevents occurrence of ghost caused by response delay of a liquid crystal and prevents occurrence of luminance non-uniformity. SOLUTION: A gradation value conversion table for compensating for delay of a response by accelerating a response speed of the liquid crystal to a gradation change by intensifying a gradation voltage for image display of a latest field and giving it to a liquid crystal display panel 28 as a compensated gradation voltage is prepared for each of gate lines of the liquid crystal display panel 28, thereby compensating for a gradation value to change an application voltage in accordance with the time from data write to ON of a light source. COPYRIGHT: (C)2006,JPO&NCIPI

A lower troposphere Radar: 1.3-GHz active phased-array type wind profiler with RASS

Abstract: We have developed an atmospheric radar (wind profiler) for lower tropospheric observations (Lower Troposphere Radar: LTR), based on the 1357.5-MHz boundary layer radar (BLR), which we previously developed mainly for observations of the atmospheric boundary layer. System gain of this radar is improved due to newly developed large-sized active phased-array antenna, active transmitting modules with higher output power, and pulse compression technique. It has the following functions: an antenna gain of 33 dBi is obtained with a 4 m × 4 m active phased array antenna which has 96 antenna subelements, a peak output power of 2 kW is obtained by 24 active transmitting modules, and maximum S/N is improved 8 times by using a pulse compression technique which uses 8-bit optimized coding developed by Spano and Ghebrebrhan (1996c). The LTR is the first active phased-array 1.3 GHz-band wind profiler radar. It is possible to vary the beam direction by electronically steering the zenith angle within 45°. Atmospheric winds in the lower troposphere, including the atmospheric boundary layer, are obtained with high time and height resolutions in real time. Observations of atmospheric temperature are also possible using the radio acoustic sounding system (RASS) technique with speaker horns. We have confirmed LTR’s potential as a reliable tool for atmospheric observations, using simultaneous observation results with the MU (Middle and Upper atmosphere) radar, a Doppler sodar, and a radiosonde.

Motion-based text input

Abstract: A method generates input text with a pointing device at a distance from a writing surface. Motion information of a mobile coordinate frame of the pointing device is sensed relative to a stationary coordinate frame of the writing surface using a motion sensor configured to track motion of the pointing device. The input text is then determined from the motion information. A projection of a track of the motion of the pointing device on the writing surface can also be determined from the motion information, and the track can be displayed on the writing surface as the input text.

Base station and radio terminal

Abstract: A base station for a wireless LAN system has physical layers corresponding to channels, and a MAC layer. The physical layers each transmits and receives a radio signal conforming to an IEEE 802.11 standard using a corresponding channel. When transmitting, the MAC layer divides an entire data frame conforming to the standard from a head of the data frame, in accordance with a transmission rate of each physical layer, and allots the divided data frame to the physical layers so that burst times of the channels are substantially equal. When receiving, the MAC layer combines data frames received via channels through operations opposite to those performed when transmitting.

Design of superconducting combined function magnets for the 50 GeV proton beam line for the J-PARC neutrino experiment

Abstract: Superconducting combined function magnets will be utilized for the 50 GeV-750 kW proton beam line for the J-PARC neutrino experiment and an R&D program has been launched at KEK. The magnet is designed to provide a combined function with a dipole field of 2.59 T and a quadrupole field of 18.7 T/m in a coil aperture of 173.4 mm. A single layer coil is proposed to reduce the fabrication cost and the coil arrangement in the 2D cross-section results in left-right asymmetry. This paper reports the design study of the magnet.

70-GHz-spaced 40/spl times/42.7 Gb/s transpacific transmission over 9400 km using prefiltered CSRZ-DPSK signals, all-Raman repeaters, and symmetrically dispersion-managed fiber spans

Abstract: 70-GHz-spaced 40/spl times/42.7 Gb/s prefiltered carrier-suppressed return-to-zero differential phase-shift keying (CSRZ-DPSK) signals have been transmitted over transpacific distances for the first time, using all-Raman repeaters with two pump-wavelengths, dispersion-managed fiber commercially available in volume, and an ETDM receiver. In this paper, first, in order to enhance the spectral efficiency, the impact of bandlimitation to a CSRZ-DPSK signal was experimentally investigated in comparison to a conventional CSRZ-on-off-keying (OOK) signal, and we found that the bandlimitation tolerance of CSRZ-DPSK signal was smaller than that of CSRZ-OOK signal in back-to-back condition. We also confirmed that the prefiltering CSRZ-DPSK signal with up to 65 GHz bandlimitation potentially had better transmission performance than the prefiltered CSRZ-OOK signal. In addition, we found that, although the nonlinear transmission penalty was increased by bandlimitation, this penalty for CSRZ-DPSK signal was smaller than that for CSRZ-OOK signal. Through this study, long-term stability of the transmission performance was also evaluated with low-speed signal polarization scrambling without using any polarization mode dispersion (PMD) compensation.

Thermal micro pumps for a loop-type micro channel

Abstract: We have developed thermal micro pumps for a loop-type micro channel, realizing an active micro heat transport device capable of highly efficient cooling. The thermal micro pumps make use of the time change in the vapor pressure of the working fluid as the driving force for fluid circulation. Because it has no mechanically moving elements, it is highly reliable and moreover is effective in preventing the deterioration of the heat transport rate due to miniaturization. First we fabricated an experimental loop-type micro channel with one thermal micro pump as the basic study. The circulation rate of the fluid was confirmed to be 2 mm/s at the heat calorific power of 0.7 W (2 Hz). In order to improve the circulation rate of the fluid, we set up a system with two thermal micro pumps within one loop to repeat evaporation and concentration alternately in the micro channel so as to enable the absorption of the volume change within the micro channel. Further, we made improvements not only to enable the use of the difference in the channel resistance between the valves but also the difference in the capillary diameter. We fabricated a U-shaped double loop micro channel, which has a width of 600 μm, a depth of 120 μm and a channel length of 220 mm. We confirmed a flow rate of 12.5 mm/s at the driving frequency of 1 Hz, enabling a heat transport of 0.16 W.

A technique for noninvasive respiratory gated radiation treatment system based on a real time 3D ultrasound image correlation: a phantom study.

Abstract: This paper proposes a new respiratory gated radiation treatment system that allows real-time tumor localization while avoiding invasive operation to a patient. The proposed system employs a three-dimensional (3D) ultrasound device, a 3D digital localizer, and a real-time image processing system. At the planning time, CT and 3D ultrasound reference data are simultaneously acquired under a breath-hold condition. At the treatment time, ultrasound data on three orthogonal planes are acquired and transferred to the image processing system on a real-time basis. Subsequently, normalized image correlation indices using the reference and the real-time ultrasound data are calculated for the three orthogonal planes after performing real-time coordinate transform using the 3D digital localizer attached to an ultrasound probe. Prior to the system execution, the coordinate transform matrices are partially calculated using an ultrasound calibration phantom and the 3D digital localizer. A trigger pulse to a linac can be generated when the normalized image correlation index exceeds a predetermined threshold level. Experiments have been carried out using a moving-target phantom that simulates a patient respiratory motion. We have observed that the variation of the calculated real-time correlation index synchronizes with the periodical motion of the moving-target, suggesting that real-time localization for a moving tumor is feasible with the proposed system.

Display orientation adjustment apparatus

Abstract: A movable part 10 of a display orientation adjustment apparatus H is attached to a rear surface of a display, and pivotably supported by a base 20, and its pivotal motion is restricted by a stopper 50 within a permissible range. If the movable part 10 is pivoted beyond the restricted range by a pivoting force of a predetermined magnitude or greater, the stopper 50 is released. Therefore, even if the display is pivoted inadvertently beyond the permissible range of the pivotal motion, breakage of components thereof would never take place, and its normal state of use can easily be restored.

High efficiency feed-forward amplifier using RF predistortion linearizer and the modified Doherty amplifier

Abstract: The prototype model of the high efficiency feed-forward amplifier using RF predistortion linearizer and the modified Doherty amplifier is developed, and the performance of the developed amplifier is examined experimentally. The efficiency of 13.6% with the output power of 45W is achieved under the condition that ACLR (Adjacent Channel Leakage Power Ratio) is -55 dBc in 3 GPP test method at room temperature of +25/spl deg/C. This is the top level performance among the previously reported feed-forward amplifiers for cellular base stations. In concerning with the modified Doherty amplifier, which is the key component to enhance the efficiency of feed-forward amplifier, the design method and its performance is described in detail.