Showing papers by "Mitsubishi Electric published in 2010"

Fully secure functional encryption: attribute-based encryption and (hierarchical) inner product encryption

Abstract: We present two fully secure functional encryption schemes: a fully secure attribute-based encryption (ABE) scheme and a fully secure (attribute-hiding) predicate encryption (PE) scheme for inner-product predicates. In both cases, previous constructions were only proven to be selectively secure. Both results use novel strategies to adapt the dual system encryption methodology introduced by Waters. We construct our ABE scheme in composite order bilinear groups, and prove its security from three static assumptions. Our ABE scheme supports arbitrary monotone access formulas. Our predicate encryption scheme is constructed via a new approach on bilinear pairings using the notion of dual pairing vector spaces proposed by Okamoto and Takashima.

Fully secure functional encryption with general relations from the decisional linear assumption

Abstract: This paper presents a fully secure functional encryption scheme for a wide class of relations, that are specified by nonmonotone access structures combined with inner-product relations. The security is proven under a well-established assumption, the decisional linear (DLIN) assumption, in the standard model. The proposed functional encryption scheme covers, as special cases, (1) key-policy and ciphertext-policy attribute-based encryption with non-monotone access structures, and (2) (hierarchical) predicate encryption with inner-product relations and functional encryption with non-zero inner-product relations.

Image encoding device, image decoding device, image encoding method, and image decoding method

Abstract: An encoding device includes a color component separating unit for separating an input bit stream for the respective color components, a block dividing unit for dividing an input color component signal into blocks to generate a signal of an encoding unit area, a predicted image generating unit for generating a predicted image for the signal, a determining unit for determining a prediction mode used for encoding according to a prediction efficiency of the predicted image, a prediction error encoding unit for encoding a difference between the predicted image corresponding to the prediction mode determined by the determining unit and the input color component signal, and an encoding unit for variable length-coding the prediction mode, an output from the prediction error encoding unit, and a color component identification flag indicating the color component to which the input bit stream belongs as a result of the color component separation.

The glitch PUF: a new delay-PUF architecture exploiting glitch shapes

Abstract: In this paper we propose a new Delay-PUF architecture that is expected to solve the current problem of Delay-PUF that it is easy to predict the relation between delay information and generated information. Our architecture exploits glitches that behave non-linearly from delay variation between gates and the characteristic of pulse propagation of each gate. We call this architecture Glitch PUF. In this paper, we present a concrete structure of Glitch PUF. We then show the evaluation results on the randomness and statistical properties of Glitch PUF. In addition, we present a simple scheme to evaluate Delay-PUFs by simulation at the design stage. We show the consistency of the evaluation results for real chips and those by simulation for Glitch PUF.

Speech recognition apparatus

Abstract: There are included a speech recognition unit (3) that speech-recognizes an input speech; a speech recognition dictionary (4) in which the words of the speech-recognized input speech are registered; a response speech data storage unit (6) that stores recorded speech data of the words registered in the speech recognition dictionary (4); an interaction control unit (7) that, when the speech recognition unit (3) speech-recognizes words registered in the speech recognition dictionary (4), acquires, from the response speech data storage unit (6), the recorded speech data corresponding to those words; a reproduction noise reduction unit (8) that performs a process to reduce the noises included in the recorded speech data acquired by the interaction control unit (7) from the response speech data storage unit (6); an amplitude adjustment unit (9) that adjusts the amplitude of the recorded speech data, in which the noises have been reduced by the reproduction noise reduction unit (8), to a predetermined speech level of amplitude; and a speech reproduction unit (10) that reproduces the recorded speech data outputted, for reproduction, by the amplitude adjustment unit (9)

IEEE 1901 access system: An overview of its uniqueness and motivation

Abstract: In 2005 the IEEE P1901 Working Group began standardization activities for broadband over power line networks. The process is now in its final stages, and the latest P1901 draft standard is available for sale to the public. The standard is designed to meet both in-home multimedia and utility application requirements including smart grid. The utility requirements and the resulting features that support those requirements were clustered together and form the basis of what is referred to as the utility access cluster. This article explains the aspects of P1901 power line communication technologies designed to address the access cluster. The differences between access and in-home applications, including addressing methods, clock synchronization, smart repetition, quality of service, power saving, and other access unique mechanisms, are also explained.

Light source device

Abstract: Included are, a module fixing body having a plurality of mounting holes into which laser modules are fitted and accommodated, respectively; an electricity-supplying member having an end provided with electricity-supplying terminals, which are connected to electricity-receiving terminals of the laser module accommodated in the mounting hole; and a cooling member that cools each of the laser modules. A groove in which the electricity-supplying member is accommodated is formed in a surface of the module fixing body, and the cooling member is closely arranged on the surface of the module fixing body.

Industrial robot system

Abstract: Provided is an industrial robot system which enables a reduction in an installation/adjustment period, and an increase in a no-error continuous operation period, and includes an action planning section (4) for temporary halts, an error-inducing-task restraining section (5), a section (6) for teaching task, an operation mastering section (7), a hand library (8), an optimum-task-operation generating section (11), a specific task library (9), an error-recovery-task teaching section (12), an error recovery library (10), a finger-eye-camera measurement section (32), a three-dimensional recognition section (33), a controller (30), a manipulator (31), and a universal hand contained in a manipulation device group (34)

Induction cooking device

Abstract: Disclosed is an induction cooking device which is provided with a center coil wound in a planar shape, a plurality of peripheral coils positioned on the periphery of the center coil, a plurality of power supply circuits for supplying high-frequency current independently to the center coil and each of the peripheral coils, a detection means for detecting the state of placement when the item to be heated is placed above the center coil and each peripheral coil, and a drive controller for controlling the power supply circuits so that the high-frequency current is selectively supplied to the center coil and each peripheral coil in accordance with the state of placement of the item to be heated which is detected by the detection means. This induction cooking device can suppress the generation of unneeded magnetic flux, which does not contribute to heating, and provide very efficient heating in response to the state of placement of a pot (different size or shape of the pot, and the positional offset of the pot in place) above each coil by using the center coil and the plurality of peripheral coils.

Flow rate measuring apparatus

Abstract: A flow rate measuring apparatus includes: a flow rate detecting device placed in an intake passage; a detection circuit for outputting an analog signal varying depending on the flow rate; a conversion circuit for converting the analog signal to a digital signal; a temperature detecting device for detecting an ambient temperature; and a correction circuit for primarily correcting the digital signal using a gain and/or an offset (correction coefficient) that can set the temperature coefficient in any appropriate way. The gain and/or the offset vary depending on the temperature coefficient set in any appropriate way and the ambient temperature detected by the temperature detecting device. Also, a plurality of the gains and/or the offsets are set depending on the flow rate, allowing the temperature characteristic error in flow rate measurement to be reduced.

Control apparatus for an internal combustion engine

Abstract: A control apparatus for an internal combustion engine includes: an abnormal combustion detection unit for detecting an abnormal combustion due to self-ignition occurring; a pre-ignition determination unit for detecting abnormal combustion occurrence timing based on abnormal combustion detection information to determine whether or not the abnormal combustion is the pre-ignition based on comparison between pre-ignition determination timing and the abnormal combustion occurrence timing; a heat-source pre-ignition determination unit for determining whether the pre-ignition is the heat-source pre-ignition or the compression pre-ignition based on comparison between the abnormal combustion occurrence timing set by the pre-ignition determination timing and heat-source pre-ignition determination timing; a first avoidance unit for avoiding the heat-source pre-ignition in a case where the pre-ignition is determined as the heat-source pre-ignition; and a second avoidance unit for avoiding the compression pre-ignition in a case where the pre-ignition is determined as the compression pre-ignition.

Display device and method for manufacturing same

Abstract: Disclosed is a display device having improved display quality, reliability and the like, wherein the concentration of a stress in a curved display panel is suppressed. Specifically disclosed is a display device (50) which comprises a display panel (52), an adhesive layer (308) and a supporting substrate (302). The adhesive layer (308) is provided on the display panel (52). The supporting substrate (302) is configured of a member that is provided with a curved surface (304) in advance. The display panel (52) is bonded to the curved surface (304) of the supporting substrate (302) by the adhesive layer (308). The supporting substrate (302) supports the display panel (52) in such a manner that the display panel (52) has a curved shape along the curved surface (304).

Electric power steering control device

Abstract: An electric power steering control device includes: a vibration extracting filter for performing filter processing on a rotation speed of a motor to reduce a gain on a low frequency side so as to output a vibration-component signal; a current variable gain map for detecting a current flowing through the motor as a first state quantity so as to calculate a current variable gain based on the current; a rotation-speed variable gain map for detecting the rotation speed of the motor as a second state quantity so as to calculate a rotation-speed variable gain based on the rotation speed; a correction mechanism calculating a vibration suppression current; and current controller calculating a target current so as to control the current flowing through the motor.

Fabrication of Terahertz Planar Metamaterials Using a Super-Fine Ink-Jet Printer

Abstract: Super-fine ink-jet (SIJ) printing technology is applied to the fabrication of terahertz metamaterials. A silver film is fabricated using an SIJ printer with silver paste ink, and it is confirmed that the film behaves as a good conductor in the terahertz frequency region. Then, basic terahertz metamaterials such as metal wire-grid structures and split-ring resonators are printed on high-resistivity silicon substrates. The terahertz responses of the printed samples agree with those expected from their structures. SIJ printing is one of the ideal methods for fabricating terahertz metamaterials owing to its rapidity, simplicity, flexibility, and sufficient accuracy.

A review of OFDMA and single-carrier FDMA

Abstract: The debate on OFDM vs. single-carrier (SC) transmission started back in the 1980s at the time of the European Digital Audio Broadcasting (DAB) and Digital Video Broadcasting (DVB) projects. The same questions arose later in wireless communications, and OFDM transmission with TDMA was adopted in the IEEE 802.11a specifications for wireless local area networks and by the WiMAX Forum for fixed WiMAX systems. Later, orthogonal frequency-division multiple access (OFDMA) was adopted by the WiMAX Forum for mobile WiMAX systems and more recently by the 3GPP for the downlink of Long Term Evolution (LTE) systems. In contrast, single-carrier FDMA was adopted for the uplink of LTE. In this overview paper, we will review these historic developments and give some recent results on OFDMA and Single-Carrier FDMA.

Development and field experiences of stabilization system using 34MW NAS batteries for a 51MW wind farm

Abstract: Wind turbines (WTs) are considered to be one of effective approach to solve global warming and energy issues. However, the output of WTs depends on the weather conditions and the natural environment, which cause large fluctuations in the output power, leading to insufficient of frequency adjustment capacity of the power grid. Several methods have been examined to compensate for such large fluctuations using batteries. In this paper, we describe the development of the world's largest constant output stabilization system using 34 MW sodium sulfur (NAS) batteries for a 51 MW wind farm at Futamata in the Tohoku district of Japan, as well as our field experiences indicating excellent operating performance.

Multi-screen display device

Abstract: There has been a problem of displacement of luminance and chromaticity among multiple screens due to a temperature change and a temporal change of a light source of the screen. The present invention provides a multi-screen display device including a plurality of image display devices, in which one master device and one or a plurality of slave devices communicable with the master device are included, each of the image display devices is provided with a DMD that modulates light of a light source, a screen that projects an image by modulated output light of the DMD, and an RGB luminance sensor that detects luminance of light from the DMD in an off-state, to output a luminance detection value, the master device is provided with a setting part that sets a luminance setting value unified among the plurality of image display devices based on a value in accordance with the luminance detection values, and each image display device is further provided with a luminance/chromaticity corrector that controls luminance/chromaticity of an image displayed on the screen based on the luminance setting value.

Method for manufacturing silicon carbide semiconductor device

Abstract: An object of the invention is to provide a method for manufacturing a silicon carbide semiconductor device having constant characteristics with reduced variations in forward characteristics. The method for manufacturing the silicon carbide semiconductor device according to the invention includes the steps of: (a) preparing a silicon carbide substrate; (b) forming an epitaxial layer on a first main surface of the silicon carbide substrate; (c) forming a protective film on the epitaxial layer; (d) forming a first metal layer on a second main surface of the silicon carbide substrate; (e) applying heat treatment to the silicon carbide substrate at a predetermined temperature to form an ohmic junction between the first metal layer and the second main surface of the silicon carbide substrate; (f) removing the protective film; (g) forming a second metal layer on the epitaxial layer; and (h) applying heat treatment to the silicon carbide substrate at a temperature from 400° C. to 600° C. to form a Schottky junction of desired characteristics between the second metal layer and the epitaxial layer.

Gate drive circuit

Abstract: A gate drive circuit includes a turn-on circuit having an upper limiter for receiving a gate drive signal. The upper limiter has an output terminal. The turn-on circuit also has a transistor having a base connected to the output terminal of the upper limiter. In addition, the terminal has a terminal connected to a gate of a power switching device. The upper limiter limits a voltage input to the base of the transistor to not exceed a first predetermined value.

A triple-concatenated FEC using soft-decision decoding for 100 Gb/s optical transmission

Abstract: We propose a novel triple-concatenated forward error correction for 100Gb/s transmission. Simulation shows that a net coding gain of 10.8dB is obtained by a soft-decision LPDC code concatenated with the enhanced FEC listed in G.975.1.

Charging control apparatus

Abstract: Disclosed is a charging control apparatus including: a communication unit 9 that communicates with a charge vehicle 3; an electric fee table 7 in which data that indicates a change of an electric fee with the elapse of time of a system power 4 is set; and a charging schedule processing unit 8 that acquires from the charge vehicle 3 a residual capacity of a battery 27 installed in the charge vehicle 3 via the communication unit 9, and plans a charging schedule to charge the battery 27 from the residual capacity of the battery 27 to a predetermined charge amount at the cheapest electric fee by a predetermined date and time, based on the electric fee table 7.

Rotor of permanent magnet embedded motor, blower, and compressor

Abstract: A rotor of a permanent magnet embedded motor includes a rotor iron core formed by stacking a predetermined number of magnetic steel sheets punched into predetermined shapes, a plurality of permanent-magnet insertion holes formed along an outer circumferential portion of the rotor iron core and each including permanent-magnet end-portion cavities on its both ends, a plurality of permanent magnets inserted into the permanent-magnet insertion holes, and a plurality of slits formed in the outer-peripheral side iron core portion outside of each permanent-magnet insertion holes, wherein a distance between a first slit present in a radial direction of each of the end portions of the permanent magnets and a second slit, which is adjacent to the first slit and closer to the center of its magnetic pole, is smaller than a distance between those slits other than the first and second slits.

Dc-dc power conversion apparatus

Abstract: A DC/DC power conversion apparatus includes a reactor connected to a DC power supply and a DC voltage conversion section connected to the reactor. The DC voltage conversion section includes a plurality of switching devices, a charge-discharge capacitor which is charged or discharged by ON/OFF operations of the switching devices, a plurality of diodes which provide a charging route and a discharging route for the charge-discharge capacitor. The DC/DC power conversion apparatus also includes a smoothing capacitor on an output side, which is connected to the DC voltage conversion section and including a plurality of voltage division capacitors connected in series to each other, and a switching device for voltage equalization provided on a connection line provided between the negative terminal of the charge-discharge capacitor and a connection point between the voltage division capacitors.

Semiconductor light-emitting element and method for manufacturing the same

Abstract: A semiconductor light-emitting element comprises: a semiconductor substrate; a semiconductor laminated structure including a first conductivity-type semiconductor layer, an active layer, a second conductivity-type semiconductor layer, and a contact layer that are sequentially laminated on the semiconductor substrate; a ridge portion in an upper portion of the semiconductor laminated structure; a channel portion adjoining opposite sides of the ridge portion; a terrace portion adjoining opposite sides of the channel portion and, with the channel portion, sandwiching the ridge portion; a first insulating film covering the channel portion and having openings on the ridge portion and the terrace portion; a single-layer adhesive layer on the first insulating film; a Pd electrode on the ridge portion and a part of the single-layer adhesive layer and electrically connected to the contact layer of the ridge portion; and a second insulating layer covering a portion not covered by the Pd electrode of the single-layer adhesive layer, and the terrace portion.

On a Global Complexity Bound of the Levenberg-Marquardt Method

Abstract: In this paper, we investigate a global complexity bound of the Levenberg-Marquardt method (LMM) for the nonlinear least squares problem. The global complexity bound for an iterative method solving unconstrained minimization of φ is an upper bound to the number of iterations required to get an approximate solution, such that ‖∇φ(x)‖≤e. We show that the global complexity bound of the LMM is O(e −2).

Dc / dc power converter

Abstract: Disclosed is a DC/DC power converter wherein mean power consumption can be reduced over a wide range of DC voltage ratios. A control circuit (120) changes a switching frequency (f) at which IGBTs (S1-S4) are turned ON/OFF in accordance with a voltage ratio (k) on the basis of the following equations, so that the magnitude (ΔI) of the current ripple flowing in a reactor (Lc) is a prescribed fixed value irrespective of the voltage ratio (k) (k = V2 / V1) of the DC voltage conversion. When 1 ≦ k ＜ 2: f = (V1 / (2 × L × ΔI)) × (k - 1) × (2 - k) / k When k ＞ 2: f = (V1 / (2 × L × ΔI)) × (k - 2) / k

Random Walk Based Routing Protocol for Wireless Sensor Networks

Abstract: In recent years, design of wireless sensor networks using methodologies and mechanisms from other disciplines has gained popularity for addressing many networking aspects and providing more flexible and robust algorithms. We address in this paper the problem of random walk to model routing for data gathering in wireless sensor networks. While at first glance, this approach may seem to be overly simplistic and highly inefficient, many encouraging results that prove its comparability with other approaches have been obtained over the years. In this approach, a packet generated from a given sensor node performs a random motion until reaching a sink node where it is collected. The objective of this paper is to give an analytical model to evaluate the performance of the envisioned routing scheme with special attention to two metrics: the mean system data gathering delay and the induced spatial distribution of energy consumption. The main result shows that this approach achieves acceptable performance for applications without too stringent QoS requirements provided that the ratio of sink nodes over the total number of sensor nodes is carefully tuned.

Refrigerating cycle apparatus

Abstract: A refrigerating cycle apparatus is obtained that can determine excess/shortage of a refrigerant amount in a refrigerating circuit at high precision even if a factor such as a heat exchanger whose refrigerant amount is difficult to calculate exists. The refrigerating cycle apparatus according to the present invention includes one heat source unit or more, one utilization unit or more, a refrigerating circuit constituted by the heat source unit and utilization unit, a storage part which stores an appropriate refrigerant amount of a refrigerant to be charged in the refrigerating circuit and a correction coefficient which corrects a liquid refrigerant amount such that calculation of the refrigerant amount of each constituent element of the refrigerating circuit is equal to the appropriate refrigerant amount, a measurement part which detects an operation state amount in each constituent element of the refrigerating circuit, a calculation part which calculates the refrigerant amount of each constituent element of the refrigerating circuit based on the operation state amount by using the correction coefficient, a comparison part which compares the appropriate refrigerant amount with a calculative refrigerant amount calculated by the calculation part, and a determination part which determines excess/shortage of the refrigerant amount charged in the refrigerating circuit based on a comparison result of the comparison part.

Mulit-screen display device

Abstract: A multi-screen display device of the present invention includes a master liquid crystal display device and one or more slave liquid crystal display devices which are mutually communicable with each other. Each of the liquid crystal display devices includes an LCD panel, a brightness sensor, brightness adjustment value adjustment means, and backlight control means. The brightness sensor is provided on a rear face side of the LCD panel, and detects the brightness of a backlight. The brightness adjustment value adjustment means adjusts a brightness adjustment value based on a result of comparison between a brightness measured by the brightness sensor and target brightness. The backlight control means adjusts the brightness of the LCD panel by controlling a time period for lighting the backlight based on the brightness adjustment value. The master liquid crystal display device further has target brightness adjustment means for receiving the brightness adjustment values from the slave liquid crystal display devices and adjusting the target brightness based on the brightness adjustment values of all of said liquid crystal display devices including the master liquid crystal display device itself.