Kabushiki Kaisha Yaskawa Denki and Nagaoka University | Date: 2014-10-08
A matrix converter according to an embodiment includes a power converter having a plurality of bidirectional switches, a controller configured to control the power converter, and a current detector configured to detect a current flowing to an output side of the power converter. The controller extracts a high-frequency component contained in the current detected by the current detector, adjusts an output current reference on the basis of the high-frequency component, and controls the power converter on the basis of the adjusted output current reference.
PASCO Corporation and Nagaoka University | Date: 2011-08-03
It is aimed to enable analyzing vegetation growth conditions at multiple times of a year accurately using radar images obtainable from a flying body such as artificial satellites, etc. A plurality of radar images of a ground surface of a same target area, which have been taken at multiple times of a year by a radar device mounted on a flying body, are acquired. The acquired plurality of radar images is stored in a map database. While using as a criterion image a radar image of the plurality of radar images stored in the map database, taken at a predetermined time in the multiple times of a year, other radar images than the criterion image of the plurality of radar images, taken at other times than the predetermined time in the multiple times of a year, are aligned with the criterion image, respectively. Then, backscatter coefficients of specified areas in the plurality of radar images are extracted. Based on a backscatter coefficient of a specified area in the criterion image of the plurality of radar images stored in the map database, backscatter coefficients of other radar images than the criterion image of the plurality of radar images are calibrated. And, based on a correlation between backscatter coefficients of radar images and growth values of vegetation shown in the radar images, growth values of vegetation shown in other radar images than the criterion image of the plurality of radar images, whose backscatter coefficients have been calibrated in the calibrating step, are calculated using the calibrated backscatter coefficients.
Daihen Corporation, Kyoto University and Nagaoka University | Date: 2010-06-16
The PWM signal generator of the present invention generates a first pulse waveform in which a first on-time T_(1) calculated by a first on-time calculator (401) is used as an on-duration, and a second pulse waveform in which a second on-time T_(2), calculated by a second on-time calculator (402) when a preset delay time has elapsed from the start of the calculation of the first on-time T_(1), is used as an on-duration. Also, a PWM signal generator (413) generates a PWM signal on the basis of a composite pulse in which the generated first pulse waveform and second pulse waveform are combined, and the first on-time calculator (401) calculates the first on-time T_(1) at the end of the composite pulse waveform.
Nagaoka University and Nippon Electrical Glass Co. | Date: 2011-03-16
The crystallized glass according to the present invention contains a LiVOPO_(4) crystal. The LiVOPO_(4) crystal is preferably a -LiVOPO_(4) crystal. In addition, the crystallized glass according to the present invention preferably contains a composition of Li_(2)O: 25-60%, V_(2)O_(5): 20-40% and P_(2)O_(5): 20-40% in terms of mol%. The crystallized glass according to the present invention is suitable as a positive electrode material for lithium ion secondary batteries. The present invention provides a substance suitable as a positive electrode material for a lithium secondary battery having good battery properties and a method for producing the substance.
Daihatsu Motor Co. and Nagaoka University | Date: 2016-09-28
A power generation system includes: a heat source having a temperature being changed over time; a flow passage through which a heat medium heated by the heat source passes; a power generation device including a power generation element and a first electrode, the power generation element being electrically polarized by temperature change thereof depending on temperature change of the heat medium, the first electrode extracting electric power from the power generation element; a temperature detection device being disposed on an upstream side relative to the power generation device in the flow passage and detecting the temperature of the heat medium; a voltage application device that applies voltage to the power generation element; and a control device that activates the voltage application device when the temperature increase of the heat medium has been detected and deactivates the voltage application unit when the temperature decrease of the heat medium has been detected.
Honma T.,Nagaoka University |
Togashi T.,Nagaoka University |
Ito N.,Nagaoka University |
Komatsu T.,Nagaoka University
Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan | Year: 2012
New cathode candidate Na 2FeP 2O 7 for rechargeable sodium ion second battery was successfully prepared by glass-ceramics method. The precursor glass, which is same composition in Na 2FeP 2O 7, was prepared by melt-quenching method. Na 2FeP 2O 7 was obtained by heat treatment of precursor glass powder with 10% glucose addition as reduction agent of Fe 3+ at 620°C for 3 h in electric furnace. Na 2FeP 2O 7 has triclinic P1-structure with a = 0.64061 nm, b = 0.938893 nm, c = 1.09716 nm, α = 64.5381°, β = 86.0580°, γ = 73.0619°. By means of electrochemical chargedischarge testing, Na 2FeP 2O 7 exhibits 2.9V, 88mAh/g, in which is 90% for the theoretical capacity during 2.03.8V cut-off voltages. Na 2FeP 2O 7 ceramics has the potential for the safety cathode candidate for the sodium ion battery with a low materials cost. © 2012 The Ceramic Society of Japan. All rights reserved.
Nagaoka University | Date: 2012-09-05
The light from the light source of the broadband light is reflected by VIPA so that reflection distance changes step by step. In VIPA, the light that phase changed is generated depending on the depth of the step. Interference profile is measured by this reflected light and optical path length modulator by synthetic light with the generated light frequency comb. The interferometer does not have a movable scanning mechanism, and the operation of the Fourier transform is unnecessary.Thus, it has the measurement of the short time. Also, measurement of the measurement of the coaxial tomography and the one-dimensional dislocation of the depth direction is possible. The measurement of the two-dimensional dislocation of the depth direction is possible.
Nagaoka University | Date: 2013-03-06
Every depth of the measurement object measures energy structural information, refractive index, transmittance, reflectance other than property information of (as for the resolution several microns), e.g., space information at the same time. A spectrum measurement device receives a reference wave propagating in a reference path and a measurement wave propagating in a measurement path having a start point same as a start point of the reference path, and derives a spectrum of the measurement wave. The space information of the measuring object, energy structural information, refractive index, transmittance, a reflective index using spectrum measurement device are derived.
Nagaoka University | Date: 2012-09-05
It detects the relative phase of two measured signals using two reference signals. The relative phase detector 1 comprises reference signal generator 11, beat signal processor 12 and detecting element 13. As for reference signal generator 11, a frequency interval generates two reference signals which are the same as the frequency interval of the measured signal of two above. The beat signal processor 12 generates two beat signals from the reference signal of two measured signals and two above, and generation does the multiplication signal of these two beat signals. It removes constant decided by detection system from the DC component of the multiplication signal, and detecting element 13 detects the relative phase of two measured signals.
Sanden Corporation and Nagaoka University | Date: 2013-08-28
The present invention provides a magnesium alloy member and a method for manufacturing a magnesium alloy member capable of achieving a mechanical strength and a high-temperature fatigue strength sufficient to apply them to mechanical parts of a compressor for automotive air conditioners. The invention also provides a compressor for air conditioners using, as a mechanical part thereof, a magnesium alloy equipped with a necessary mechanical strength and high-temperature fatigue strength. More specifically, a magnesium alloy member is formed by subjecting a cast material of a magnesium alloy containing, on the basis of mass%, from 0.3% to 10% calcium (Ca), from 0.2% to 15% aluminum (Al), and from 0.05% to 1.5% manganese (Mn), and containing calcium (Ca) and aluminum (Al) at a calcium/aluminum mass ratio of from 0.6 to 1.7, with the balance being magnesium (Mg) and inevitable impurities to plastic working (extrusion processing) at from 250C to 500C. This makes it possible to obtain a magnesium alloy member having a room-temperature 0.2% proof stress of 300 MPa or more and a 150C fatigue strength of 100 MPa or greater. The magnesium alloy member used for the formation of mechanical parts of a compressor for automotive air conditioners contributes to a reduction in the weight of the compressor.