225 results
Search Results
2. An Approach to Guidance Motion by Gait-Training Equipment in Semipassive Walking.
- Author
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Nakano, Keisuke and Murakami, Toshiyuki
- Subjects
BIRTH rate ,MOTION ,WALKING ,GAIT disorders ,WHEELCHAIRS ,GEOMETRY - Abstract
Recently, population aging and declining birth rate have become very serious, and people who lack walking capability have truly increased in Japan. To address this issue, gait training has become a requirement for them. Although some training systems have been researched in the past, a training system that entails guidance of walking has not been researched well. This paper focuses on guidance of walking, and it is aimed to develop a training system that utilizes the activity and passivity of the trainee. In addition, rhythmic walking, which takes walking stability and trainee safety into account, is aimed for. In this paper, an improved electric wheelchair is used as gait-training equipment (GTE); then, the trainee is towed by the GTE, and walking is guided. In this paper, a targeted walking cycle is predefined, and the GTE must distinguish the cycle in order to guide walking. Therefore, this paper uses the center of gravity (COG) of the trainee as the index. Thus, the GTE tows the trainee when the swing leg moves more forward than the stance leg; then, rhythmic walking can be guided. In addition, this paper proposes a method to control the GTE by a proportional-differential controller based on virtual compliance that is composed of mass, spring, and damper. The gait training can be safely achieved by deciding the desired position and velocity of the GTE from the tow force through virtual compliance. In this paper, the validity of the proposed method is verified by numerical simulation and experiment. The validity of the proposed system is verified by using a four-link robot whose geometric expression is known as the trainee; then, the application of the proposed method will be extended to a human trainee by only adjusting the parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
3. Guest Editorial Special section on the 2022 International Symposium on Semiconductor Manufacturing.
- Author
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Moriya, Tsuyoshi
- Subjects
SEMICONDUCTOR manufacturing ,SEMICONDUCTOR devices ,SEMICONDUCTOR technology ,ARTIFICIAL intelligence ,MACHINE learning ,CURRENT good manufacturing practices - Abstract
Since its beginning in 1992 in Japan, International Symposium on Semiconductor Manufacturing (ISSM) has provided unique opportunities to share the best practices of semiconductor manufacturing technologies for professionals. At the symposiums, semiconductor manufacturing professionals discussed the technologies developed to meet the worldwide requirements for advanced manufacturing. It is becoming crucial to re-examine semiconductor manufacturing in terms of fundamental principles to improve the performance of semiconductor devices. Moreover, utilizing artificial intelligence and machine learning technologies to improve semiconductor manufacturing have become a new challenge. These manufacturing technology challenges are showing the need for drastic revolutionary concept and stronger collaborative efforts to find solutions to the precompetitive challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. Current Observation Results of Downward Negative Flashes at Tokyo Skytree From 2012 to 2018.
- Author
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Miki, Toru, Saito, Mikihisa, Shindo, Takatoshi, and Ishii, Masaru
- Subjects
LIGHTNING protection ,TOWERS ,DESIGN protection ,LIGHTNING - Abstract
Direct observation of lightning current is a fundamental approach to evaluating lightning parameters, which are among the most basic factors for the lightning protection design of various grounded objects. However, for a tall grounded structure, upward lightning flashes initiated from the top of the structure have usually been observed, and the direct observation results of downward flashes have been limited. We developed and installed a pair of Rogowski coils at Tokyo Skytree, which is a 634-m-high freestanding broadcasting tower in Japan (35.71°N, 139.81°E), and have conducted direct observation of lightning flashes striking the tower. As of November 2018, 70 lightning flashes striking the tower, 26 downward and 44 upward, have been observed since the end of February 2012. In this paper, we focus on the downward negative flashes that occurred at the tower for seven years from 2012 to 2018 and report on the observed results of typical waveform parameters of lightning stroke currents in comparison with other observed results on downward negative flashes. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Detection of Lightning Damage on Wind Turbine Blades Using the SCADA System.
- Author
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Matsui, Takuto, Yamamoto, Kazuo, Sumi, Shinichi, and Triruttanapiruk, Nawakun
- Subjects
SUPERVISORY control & data acquisition systems ,WIND damage ,WIND turbine blades ,LIGHTNING ,SUPERVISORY control systems ,WIND turbines - Abstract
In recent years, there have been several reports of blade damage caused by lightning strikes on wind turbines. A few of these accidents have resulted in more serious secondary damage owing to the continued rotation of the damaged blades. To prevent the initial damage from spreading in this manner, wind farms in the regions of Japan vulnerable to winter lightning were required to introduce lightning detection systems, which can accurately detect when lightning strikes the wind turbine and then immediately stop the rotation of the blades. Normally, when the system detects a lightning strike to a wind turbine and stops operation, the process of restarting is initiated only after the soundness of the blades is confirmed by visual inspection. However, in bad weather, it is often difficult to check the soundness of the blade visually, and the resulting delay in the restart process prolongs the downtime and reduces the availability of the wind turbine. In this paper, we report the results of using the supervisory control and data acquisition (SCADA) system data to check the soundness of the blades after a lightning strike to resume operations more quickly, thereby increasing up-time. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
6. Guest Editorial to the Special Issue on Therapeutic Ultrasound: Current Status and Future Directions.
- Author
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Ebbini, Emad S.
- Subjects
MEDICAL imaging systems - Abstract
An introduction to the journal is presented in which the editor discusses an article on the results of the binary feedback control system, an article on the correlation of cavitation and temperature rise in therapeutic ultrasound, and the International Symposium on Therapeutic Ultrasound (ISTU) to be held on June 2010 in Tokyo, Japan.
- Published
- 2010
- Full Text
- View/download PDF
7. Development of Transmitter and Receiver With Set Partitioning 64APSK Coded Modulation Designed on Basis of Channel Capacity.
- Author
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Koizumi, Yuki, Suzuki, Yoichi, Kojima, Masaaki, Yokohata, Kazunori, and Sujikai, Hisashi
- Subjects
MODULATION coding ,ADDITIVE white Gaussian noise ,ULTRAHIGH definition television ,PHASE shift keying ,TRANSMITTERS (Communication) - Abstract
In this paper, we present a prototype transmitter and receiver with set partitioning (SP)-64 amplitude and phase shift keying (APSK) coded modulation we developed for expanding satellite transmission capacity. SP-multi-level coded modulation is a transmission scheme that can improve noise immunity by properly combining a modulation scheme, bit allocation, and error-correction codes. We designed SP-64APSK coded modulation on the basis of channel capacity for expanding satellite transmission capacity. We confirmed that it has higher robustness to additive white Gaussian noise (AWGN) than DVB-S2X’s 64APSK modulation with Gray mapping through computer simulation. We also developed a prototype transmitter and receiver to implement our SP-64APSK coded modulation and evaluated its transmission performances in an AWGN channel and in a non-linear channel simulating 12-GHz-band satellite transponder characteristics. We describe the method of designing our SP-64APSK coded modulation through computer simulation, the modulation/demodulation process, and transmission performances of the prototype transmitter and receiver. We also indicate that 8K ultra-high definition television (UHDTV) with an encoded bit rate of 150 Mbps can be transmitted using the prototype within 34.5 MHz, which is the bandwidth of a single transponder for satellite broadcasting in Japan. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Electrical Fatality Rate by Industry in Japan, 1974–2003.
- Author
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Ichikawa, Norimitsu
- Subjects
ELECTRIC shock ,INDUSTRIES ,ELECTRICAL injuries ,INDUSTRIAL safety ,ELECTRIC lines ,PREVENTION - Abstract
Fatal accidents caused by electric shock have been occurring since electricity was first introduced. Overall, the number of fatal accidents is decreasing. However, the decrease in the number of fatalities has slowed in recent years. A statistical study is needed to reconsider the preventive measures against these accidents. In this paper, the trend of fatalities by accident type and industry in Japan is studied statistically. These results show that the electric fatality rates differ by industry. The fatalities in the construction and the electrical-construction industries make up approximately 60% of the total fatalities. In addition, the accident type is most frequently contact with electrical lines by either the human body or a tool. In these industries, the elimination of fatal accidents from shocks is an important subject. These results will be helpful in preventing fatal accidents by electric shock. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
9. Sensitivity Analysis of Multifrequency MIMP SAR Data From Rice Paddies.
- Author
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Arii, Motofumi, Yamada, Hiroyoshi, Kojima, Shoichiro, and Ohki, Masato
- Subjects
SYNTHETIC aperture radar ,SENSITIVITY analysis ,STRUCTURE-activity relationships ,SURFACE scattering - Abstract
The determination of the accurate composition ratio of scattering mechanisms (volume scattering, double-bounce scattering, and surface scattering) within a radar backscatter is essential to validate current polarimetric decomposition techniques. Multiincidence angle and multipolarimetric synthetic aperture radar (MIMP SAR) observations at the X- and L-bands were applied to rice paddies at late vegetative stage in Niigata City in Japan in 2014 and 2016, respectively. In this paper, multifrequency MIMP SAR analysis is introduced based on the observation results. The approach, combined with theoretical characterization of the data by a discrete scatterer model, showed that rice panicles affect the backscatter from rice paddies. Contrary to expectation, an effect of transmissivity by using different bands is not obvious. The similar level of copolarization (HH and VV) backscatter at X- and L-bands could be explained by the effective size of rice panicles. They are the most characteristic scatters in rice paddy field with respect to multiple frequency polarimetric sensing. In addition, HV shows a distinct sensitivity to the mean orientation angle and the size of panicles regardless of the wavelength. The mean orientation angle affects the polarimetric randomness under azimuthal symmetry, whereas the size of panicles directly affects the attenuation of the volume scattering from the grains. The multifrequency MIMP SAR analysis also indicated the importance of considering the backscatter and attenuation in the interpretation of the backscattering cross section from vegetated fields. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
10. A Study of a Large Bipolar Lightning Event Observed at the Säntis Tower.
- Author
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Azadifar, Mohammad, Rubinstein, Marcos, Rachidi, Farhad, Rakov, Vladimir A., Diendorfer, Gerhard, Schulz, Wolfgang, and Pavanello, Davide
- Subjects
LIGHTNING ,TOWERS ,ELECTRIC fields ,SENSITIVITY analysis ,STROKE ,THUNDERSTORMS - Abstract
An unusual negative lightning flash was recorded at the Säntis Tower on June 15, 2012. The flash did not contain an initial continuous current typical of upward negative lightning, which is the most common type of event at the Säntis Tower. The flash contained four strokes, the last three of which were normal while the current associated with the first stroke resembled a Gaussian pulse with an unusually high peak value of 102.3 kA, a long risetime of 28.4 μs, and a pulsewidth of 53.8 μs, which was followed by an opposite polarity overshoot with a peak value of 8.5 kA. Our current records suggest the involvement of a long upward connecting positive leader in response to the approaching downward negative leader in the formation of this flash. Lightning location system (LLS) data indicate that a positive cloud-to-ground stroke occurred 1 ms prior to the first stroke of the flash. In this paper, we present a detailed description of the data associated with this event. Moreover, both a return stroke model and an M-component model are used to reproduce the far-field waveform of this bipolar stroke. The simulations result in a radiated electric field waveform that is similar to those of large bipolar events (LBEs) observed in winter thunderstorms in Japan. A sensitivity analysis of the used simulation models reveals that, by proper selection of the input parameters, all field waveform characteristics, except for the positive half-cycle width, can be made to fall in the range of LBE field characteristics reported in Japan. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
11. Experience of Numerical Protective Relays Operating in an Environment With High-Frequency Switching Surge in Japan.
- Author
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Matsumoto, Toshio, Kurosawa, Yasuhiro, Usui, Masaji, Yamashita, Koji, and Tanaka, Taisei
- Subjects
ELECTRIC relays ,ELECTRIC power system protection ,ELECTRIC transients ,ELECTRICAL engineering - Abstract
This paper intends to provide general information about the experiences of numerical relay operation under many different kinds of surges from switchyards in Japan. The main focus of this paper is to investigate the immunity of numerical relays against a switching surge with relatively high frequency in a gas-insulated substation that is considered to be severe for the relay's correct operation. It is concluded that the reliability of today's numerical relays in Japan against the switching surge is almost sufficient due to the effectiveness of the immunity test standard adopted and countermeasures against the switching surge in Japan. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
12. Results of All ITER TF Full-Size Joint Sample Tests in Japan.
- Author
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Kajitani, Hideki, Imagawa, Shinsaku, Obana, Tetsuhiro, Takada, Suguru, Hamaguchi, Shinji, Chikaraishi, Hirotaka, Nakamoto, Mio, Yamane, Minoru, Yoshizawa, Kazumi, Uno, Yasuhiro, Matsui, Kunihiro, Koizumi, Norikiyo, and Nakahira, Masataka
- Subjects
ELECTROMAGNETIC forces ,MAGNETIC fields ,COOLDOWN ,WARMUP ,AUTHORSHIP collaboration ,NATIONAL competency-based educational tests - Abstract
Nine toroidal field (TF) coils have been developed in Japan for the international thermonuclear experimental reactor (ITER). The joint resistance of TF coil should satisfy the requirement of smaller than 3 nano-ohm at 2 T of external magnetic field and 68 kA of transport current. Full-size joint sample (FSJS) tests were performed for joint development and for TF coil manufacture, as part of the process control. 11 FSJS tests are conducted in total. FSJS tests were conducted with assistance from a test faculty in the National Institute for Fusion Science as reported in a previous paper. All FSJS tests successfully satisfied the requirement of resistance less than 3 nΩ at 2 T. Additionally, the TF coil joints are subjected to cyclic electromagnetic force and warm-up/cool-down during the ITER operation. The authors investigated the joint performance for the abovementioned influence. The results showed no degradation in the joint resistance. Thus, the TF joint developed in Japan was qualified successfully. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Guest Editorial Special Section on the 2020 International Symposium on Semiconductor Manufacturing.
- Subjects
SEMICONDUCTOR manufacturing ,ARTIFICIAL intelligence ,SEMICONDUCTOR technology ,SEMICONDUCTOR devices ,MACHINE learning ,CONFERENCES & conventions - Abstract
Since its beginning in 1992 in Japan, International Symposium on Semiconductor Manufacturing (ISSM) has provided unique opportunities to share the best practices of semiconductor manufacturing technologies for professionals. At the symposiums, semiconductor manufacturing professionals discussed the technologies developed to meet the worldwide requirements for advanced manufacturing. It is becoming crucial to re-examine semiconductor manufacturing in terms of fundamental principles to improve the performance of semiconductor devices. Moreover, utilizing artificial intelligence and machine learning technologies to improve semiconductor manufacturing have become a new challenge. These manufacturing technology challenges are showing the need for drastic revolutionary concept and stronger collaborative efforts to find solutions to the precompetitive challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. Correlation Between Maximum Temperature Increase and Peak SAR with Different Average Schemes and Masses.
- Author
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Hirata, Akimasa, Fujimoto, Masaki, Asano, Takayuki, Jianqing Wang, Fujiwara, Osamu, and Shiozawa, Toshiyuki
- Subjects
GREEN'S functions ,BRAIN ,DIFFERENTIAL equations - Abstract
Abstract-This paper investigates the correlation between max- imum temperature increases and peak spatial-average specific ab- sorption rates (SARs), calculated by different average schemes and masses. For evaluating the effect of mass on the correlation prop- erly, a three-dimensional Green's function is presented. From our computational investigation, no best average mass for peak spatial- average SAR exist from the aspect of the correlation with maximum temperature increase. This is attributed to the frequency dependent penetration depth of EM waves. Maximum temperature increase in the head including the pinna is reasonably correlated with peak spatial-average SARs for most average schemes and masses consid- ered in this paper. Maximum temperature increase in the head only (excluding the pinna) is reasonably correlated with peak 1O-g SARs for the average schemes considered in this paper. The rationale for this result is explained using the Green's function. The point to be stressed here is that the slope correlating them is largely dependent on the average scheme and mass. Additionally, good agreement is observed in the slopes obtained by using two head models, which have been developed at Osaka University and Nagoya Institute of Technology. However, weak correlation is observed for the brain, which is caused by the difference of the positions where peak SAR and maximum temperature increase appear. The 95th percentile values of the slope correlating maximum temperature increases in the head or brain and peak spatial-average SAR are quantified for different average schemes and masses. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
15. Ice Cloud Properties From Himawari-8/AHI Next-Generation Geostationary Satellite: Capability of the AHI to Monitor the DC Cloud Generation Process.
- Author
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Letu, Husi, Nagao, Takashi M., Nakajima, Takashi Y., Riedi, Jerome, Ishimoto, Hiroshi, Baran, Anthony J., Shang, Huazhe, Sekiguchi, Miho, and Kikuchi, Maki
- Subjects
GEOSTATIONARY satellites ,ICE clouds ,METEOROLOGICAL satellites ,OPTICAL measurements ,LIGHT scattering ,REPRODUCTION - Abstract
The Japan Meteorological Agency (JMA) successfully launched the Himawari-8 (H-8) new-generation geostationary meteorological satellite with the Advanced Himawari Imager (AHI) sensor on October 7, 2014. The H-8/AHI level-2 (L2) operational cloud property products were released by the Japan Aerospace Exploration Agency during September 2016. The Voronoi light scattering model, which is a fractal ice particle habit, was utilized to develop the retrieval algorithm called “Comprehensive Analysis Program for Cloud Optical Measurement” (CAPCOM-INV)-ice for the AHI ice cloud product. In this paper, we describe the CAPCOM-INV-ice algorithm for ice cloud products from AHI data. To investigate its retrieval performance, retrieval results were compared with 2000 samples of the ice cloud optical thickness and effective particle radius values. Furthermore, AHI ice cloud products are evaluated by comparing them with the MODIS collection-6 (C6) products. As an experiment, cloud property retrievals from AHI measurements, with an observation interval time of 2.5 min and ground-based rainfall observation radar data (the latter of which is supplied by the JMA, with a 1-km grid mesh), are used to investigate the generation processes of deep convective (DC) cloud in the vicinity of the Kyushu island, Japan. It revealed that AHI measurements have the capability of monitoring the growth processes, including variation of the cloud properties and the precipitation in the DC cloud. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
16. A Full Reference Quality Metric for Compressed Video Based on Mean Squared Error and Video Content.
- Author
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Bhat, Abharana, Kannangara, Sampath, Zhao, Yafan, and Richardson, Iain
- Subjects
VIDEO coding ,HIGH resolution imaging ,MEAN square algorithms ,IMAGE quality analysis ,VIDEO compression - Abstract
Visual quality of compressed video sequences depends on factors including spatial texture content and cognition-based factors such as prior knowledge and task in hand. The MOSp metric is a full reference objective quality metric which predicts perceived quality of sequences with video compression-induced impairments based on the spatial texture content and the mean squared error between original and compressed video sequences. In this paper, we extend the MOSp metric to incorporate cognition-based factors to identify regions in a video scene that attract human attention. The proposed metric has been tested on a variety of multimedia sequences of common intermediate format resolution compressed at a wide range of bitrates using the H.264/AVC coding standard. This metric shows a higher correlation with mean opinion score (MOS) than popular metrics, such as peak signal-to noise ratio, National Telecommunications and Information Administration/Institute for Telecommunication Sciences video quality metric, PSNRplus, and the Yonsei University metric. Results also show that by extending the MOSp metric to incorporate cognition-based factors such as skin information, its correlation with subjective scores (MOS) can be significantly improved in video content where humans are present. This algorithm is particularly useful for real-time quality estimation of multimedia sequences with block-based video compression-induced impairments because all the parameters of the metric can be calculated automatically with a modest amount of processing overhead. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
17. Field Measurement on Simple Vehicle-Mounted Antenna System Using a Geostationary Satellite.
- Author
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Basari, Saito, Kazuyuki, Takahashi, Masaharu, and Ito, Koichi
- Subjects
ANTENNAS (Electronics) ,MOBILE communication systems ,MARKET segmentation ,GEOSTATIONARY satellites - Abstract
This paper presents a field measurement of a simple antenna system mounted on a vehicle by utilizing a geostationary test satellite called Engineering Test Satellite VIII (ETS-VIII). Our developed antenna system is compact, lightweight, and promising for low-cost production. The antenna system is constructed by a 16-cm patch array antenna, which has simple satellite tracking that is controlled by a control unit as the vehicle's bearing is updated from a navigation system in real time. A Global Positioning System (GPS) module is utilized for the navigation system to provide accurate information of the vehicle's position and bearing during traveling. A control unit is provided as antenna-beam control and measured-data acquisition. We thoroughly examine the developed system in field measurements under open field areas and blockage areas in order to evaluate the propagation characteristics caused by utility poles, pedestrian overpasses, and vegetation-covered roads. In this measurement, the received signal power and the average bit error rate (BER) are simultaneously retrieved. Steadily received levels and average BER are satisfactorily attained during satellite tracking in open field areas. Moreover, the fade characteristics and average BER performance are also investigated during signal blockage. The results show that different environments give different degrees of attenuation, which affects the BER performance in terms of fade depth. Ultimately, our proposed antenna system can contribute to the design of future cost-effective mobile satellite communications. [ABSTRACT FROM PUBLISHER]
- Published
- 2010
- Full Text
- View/download PDF
18. Evaluation of Improved Lightning Stroke Current Waveform Using Advanced Statistical Method.
- Author
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Okabe, Shigemitsu and Takami, Jun
- Subjects
LIGHTNING protection ,ELECTRIC spark gaps ,ELECTRIC insulators & insulation ,POLARIZATION (Electricity) - Abstract
The peak current amplitude and front duration of lightning stroke current waveforms have conventionally been evaluated independently, and severe waveform assumptions are usually adopted in the current of lightning insulation designs. If lightning stroke waveform conditions are optimized, lightning insulation specifications of power facilities can be further rationalized. This paper proposes a new statistical technique to better evaluate lightning stroke current waveforms. The characteristics of lightning stroke current waveforms (i.e., that peak amplitudes correlate with front durations) are taken into account in this technique. The proposed technique was validated with various statistical tests. The front duration currently used in the design of the ultra-high-voltage system in Japan is 1.0 μs, but the potentially more accurate value of 1.7 μs was found when waveforms were evaluated with the proposed technique, and overvoltage analyses of gas-insulated switchgear show that overvoltages decrease with longer front duration. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
19. Development of Evaluation Techniques for Air Lines in 3.5- and 1.0-mm Line Sizes.
- Author
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Horibe, Masahiro, Shida, Masaaki, and Komiyama, Koji
- Subjects
AIRLINE industry ,ELECTRIC distortion ,COMMERCIAL aeronautics ,TESTING laboratories ,CALIBRATION - Abstract
This paper summarizes the calibration of precision coaxial air lines in a 3.5-mm line size. The standard system of the National Metrology Institute of Japan (NMU) is used to accurately obtain mechanical measurements of the diameters and lengths of lines. Length compression of approximately 6.0 μm and diameter distortions caused by connections with specified torques have been observed in 3.5-mm air lines. A small insertion loss in the millimeter-wave frequency range has also been detected. Furthermore, NMIJ has established standards for scattering parameters in the frequency range up to 110 GHz for coaxial air lines in the 1.0-mm line size by the enhancement of mechanical measurement systems. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
20. On Load—Frequency Regulation With Time Delays: Design and Real-Time Implementation.
- Author
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Bevrani, Hassan and Hiyama, Takashi
- Subjects
FREQUENCIES of oscillating systems ,PID controllers ,MATRIX inequalities ,TIME delay systems ,ITERATIVE methods (Mathematics) ,ALGORITHMS - Abstract
This paper addresses a robust decentralized proportional-integral (P1) control design for power system load- frequency regulation with communication delays. In the proposed methodology, the P1-based load-frequency control (LFC) problem is reduced to a static output feedback control synthesis for a multiple-delay system. The proposed control method gives a suboptimal solution using a developed iterative linear matrix inequalities algorithm via the mixed H
2 /H∞ control technique. The control strategy is suitable for LFC applications that usually employ the PI control. To demonstrate the efficiency of the proposed control strategy, an experimental study has been performed at the Research Laboratory, Kyushu Electric Power Company, Japan. [ABSTRACT FROM AUTHOR]- Published
- 2009
- Full Text
- View/download PDF
21. JT-60SA Toroidal Field Magnet System.
- Author
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Pizzuto, A., Semeraro, L., Zani, L., Bayetti, P., Cucchiaro, A., Decool, P., della Corte, A., Di Zenobio, A., Dolgetta, N., Duchateau, J. L., Fietz, W. H., Heller, R., Hertout, P., Kikuchi, M., Kizu, K., Lacroix, B., Muzzi, L., Nicollet, S., Polli, G. M., and Portafaix, C.
- Subjects
SUPERCONDUCTORS ,CRYOTRONS ,MAGNETICS ,MAGNETS ,MAGNETISM ,SOLENOIDS ,ELECTROMAGNETS - Abstract
The Broader Approach agreement between Europe and Japan includes the construction of a fully superconducting tokamak, the JT-60 Super Advanced (JT-60SA), as a satellite experiment to ITER. In particular, the whole Toroidal Field magnet system, described in this paper, will be provided to Japan by the EU. All the TF coil main constituents, i.e. conductor, winding pack, joints, casing, current leads, are here presented and discussed as well as the design criteria adopted to fulfil the machine requirements. The results of the analyses performed by the EU and JA to define and assess the TF magnet system conceptual design are reported and commented. Future work plan is also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
22. A New Design for JT-6OSA Toroidal Field Coils Conductor and Joints.
- Author
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Zani, L., Pizzuto, A., Semeraro, L., Ciazynski, D., Cucchiaro, A., Decool, P., della Corte, A., Di Zenobio, A., Dolgetta, N., Duchateau, J.-l., Hertout, P., Kikuchi, M., Lacroix, B., Molinie, F., Muzzi, L., Nicollet, S., Petrizzi, L., Portafaix, C., Ramogida, G., and Roccella, S.
- Subjects
MANUFACTURED products ,BUSINESS logistics ,INDUSTRIAL management ,MARITIME shipping ,FREIGHT & freightage - Abstract
The upgrade of JT-60U to JT-60 Super Advanced (JT-60SA), a fully superconducting tokamak, will be performed in the framework of the Broader Approach (BA) agreement between Europe (EU) and Japan. In particular, the Toroidal Field (TF) system, which includes 18 coils, is foreseen to be procured by France, Italy and Germany. This work covers activities from design and manufacturing to shipping to Japan. The present paper is mainly devoted to the analyses that lead to the conductor design and to the technical specifications of the joints for the JT-60SA TF coils. The conductor geometry is described, which is derived from Cable-In-Conduit concept and adapted to the actual JT-60SA tokamak operating conditions, principally the ITER-like scenario. The reported simulations and calculations are particularly dealing with the stability analysis and the power deposition during normal and off-normal conditions (AC losses, nuclear heating). The final conductor solution was selected through a trade-off between scientific approach and industrial technical orientation. Besides, the TF system connections layout is shown, derived from the industrially assessed twin-box concept, together with the associated thermo-hydraulic calculations ensuring a proper temperature margin. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
23. Automatic Reconstruction of Building Objects From Multiaspect Meter-Resolution SAR Images.
- Author
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Feng Xu and Ya-Qiu Jin
- Subjects
SYNTHETIC aperture radar ,OPTICAL resolution ,BUILDING repair ,IMAGING systems ,IMAGE processing - Abstract
Reconstruction of 3-D objects from multiaspect high-resolution synthetic aperture radar (SAR) images is of great importance for SAR technology applications. In this paper, simple building objects are modeled as cuboids, and an approach for automatic reconstruction of 3-D building objects from multiaspect SAR images in meter resolution is developed. The edge detector of constant false alarm rate and a Hough transform technique for parallel line segment pairs are first employed to extract the parallelogram-like image of the building walls in SAR images. A set of probability density functions is presented to describe the object images and their multiaspect coherence. The maximum-likelihood estimation of an object is then derived from its multiaspect object images. A hybrid priority criterion is defined to evaluate the reliability of the reconstruction result. An automatic reconstruction algorithm is further developed to match object images of different aspects and, finally, to reconstruct the building objects. Besides, an iterative method is proposed for the coregistration of multiaspect building images. Four-aspect simulated images of a virtual scene and four-aspect Pi-SAR images over the campus of Tohoku University, Japan, are investigated. Reconstruction of building objects from their multiaspect images shows the fidelity of the whole process chain and the feasibility of 3-D objects automatic reconstruction from multiaspect SAR images. At last, a practical application that is based on spaceborne meter-resolution SAR is proposed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
24. FDTD-Derived Correlation of Maximum Temperature Increase and Peak SAR in Child and Adult Head Models Due to Dipole Antenna.
- Author
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Fujimoto, Masaki, Hirata, Akimasa, Jianqing Wang, Fujiwara, Osamu, and Shiozawa, Toshiyuki
- Subjects
DIPOLE antennas ,ANTENNAS (Electronics) ,ELECTRONICS - Abstract
This paper investigates the correlation between the peak specific absorption rate (SAR) and the maximum temperature increase in head models of adults and children due to a dipole antenna. Much attention is paid to the effect of variation of electrical and thermal constants on the correlation for the child models, since these constants of child tissues are different from those of adult tissues. For investigating these correlations thoroughly, a total of 1400 situations are considered for the following six models: 3-year-old child, 7-year-old child, and adult models developed at the Nagoya Institute of Technology and the Osaka the University. The numerical results are analyzed on the basis of statistics. We find that the maximum temperature increases in the head can be estimated linearly in terms of peak SAR averaged over 1- or 10-g of tissue. In particular, no clear difference is observed between the adult and child models in terms of the slopes correlating the maxi- mum temperature increase with the peak SAR. Also, the effect of electrical and thermal constants of tissue on these correlation is found to be marginal. Further, we discuss possible maximum temperature increases in the head and brain for SAR limits prescribed in safety guidelines. For the adult model developed at the Osaka Univ., these are found to be 0.26°C and 0.10°C at the SAR value of 1.6 W/kg for 1-g cubic tissue and 0.59°C and 0.21 °C at the SAR value of 2.0 W/kg for 10-g cubic tissue. Similarly, for the 3-year-old child model at Osaka Univ., these are 0.23°C and 0.11 °C for the value of 1-g SAR and 0.53°C and 0.20°C for the value of 10-g SAR. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
25. The Operational Phase of Negative Ion Beam Systems on JT-60U and LHD.
- Author
-
Grisham, Larry R.
- Subjects
ELECTRON beams ,ION sources ,STELLARATORS ,PLASMA devices ,ELECTRON accelerators - Abstract
This paper reviews the operational phase of the negative-ion-based neutral beam systems on the JT-60U tokamak in Naka, Japan and the large helical device (LHD) stellarator in Toki, Japan. These systems were the first high power negative ion beam systems to be deployed for any application, and thus represented large advances in the state of the art for negative ion sources and accelerators, especially since the ions used were hydrogen and deuterium, which have only a modest electron affinity. This paper re- views the systems, the principal problems encountered, and the improvements they engendered, as well as the progress of these systems to the present time. The role of neutral beams in fusion is also discussed, and some of the contributions of the negative ion systems to the physics programs of JT-60U and LHD are briefly reviewed. These systems have been central to the success of JT-60U and LHD, and the knowledge gained about their characteristics should provide a strong basis for the development of the next generation of negative-ion-based neutral beams for ITER and other large fusion devices. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
26. Dual-Band Circularly Polarized Equilateral Triangular-Patch Array Antenna for Mobile Satellite.
- Author
-
Sumantyo, Josaphat Tetuko Sri, Ito, Koichi, and Takahashi, Masaharu
- Subjects
ANTENNAS (Electronics) ,TELECOMMUNICATION satellites ,TELECOMMUNICATION systems ,PROTOTYPES ,COMPUTER simulation - Abstract
The Japan Aerospace Exploration Agency will launch the Engineering Test Satellite VIII (ETS-VIII) in 2006 to support the next generation of mobile satellite communications covering the area of Japan (beam coverage El = 38° to 58°). In this paper, a satellite-tracking left-handed circularly polarized triangular-patch array antenna is developed for ground applications. The targeted minimum gain of the antenna is set to 5 dBic at the central elevation angle (El = 48°), in the Tokyo area, for applications using data transfer of around a hundred kbps. The antenna is composed of three equilateral triangular patches for both reception and transmission units operating at 2.50 and 2.65 GHz frequency bands, respectively. The antenna was simulated by method of moments (MoM) analysis, and measurement of the fabricated antenna was performed to confirm the simulation results. The measurement results show that the frequency characteristics and the 5-dBic gain coverage in the conical-cut plane of the fabricated antenna satisfy the specifications for ETS-VIII. A prototype of the proposed antenna system is employed in outdoor experiments using a pseudosatellite and shows good performance from El = 38° to 58°. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
27. Global Survey and Statistics of Radio-Frequency Interference in AMSR-E Land Observations.
- Author
-
Njoku, Eni G., Ashcroft, Peter, Chan, Tsz K., and Li, Li
- Subjects
SURVEYS ,STATISTICS ,MICROWAVES ,ARTIFICIAL satellites - Abstract
Radio-frequency interference (RFI) is an increasingly serious problem for passive and active microwave sensing of the Earth. To satisfy their measurement objectives, many spaceborne passive sensors must operate in unprotected bands, and future sensors may also need to operate in unprotected bands. Data from these sensors are likely to be increasingly contaminated by RFI as the spectrum becomes more crowded. In a previous paper we reported on a preliminary investigation of RFI observed over the United States in the 6.9-GHz channels of the Advanced Microwave Scanning Radiometer (AMSR-E) on the Earth Observing System Aqua satellite. Here, we extend the analysis to an investigation of RFI in the 6.9- and 10.7-GHz AMSR-E channels over the global land domain and for a one-year observation period. The spatial and temporal characteristics of the RFI are examined by the use of spectral indices. The observed RI?! at 6.9 GHz is most densely concentrated in the United States, Japan, and the Middle East, and is sparser in Europe, while at 10.7 GHz the RFI is concentrated mostly in England, Italy, and Japan. Classification of RFI using means and standard deviations of the spectral indices is effective in identifying strong RFI. In many cases, however, it is difficult, using these indices, to distinguish weak RFI from natural geophysical variability. Geophysical retrievals using RFI-filtered data may therefore contain residual errors due to weak RFI. More robust radiometer designs and continued efforts to protect spectrum allocations will be needed in future to ensure the viability of spaceborne passive microwave sensing. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
28. Contents of Large Current Flashes Among All the Lightnings Measured on Transmission Lines.
- Author
-
Udo, T.
- Subjects
LIGHTNING ,ELECTRIC lines - Abstract
Examines the results of lightning current measurement on transmission lines in Japan. Publication of the characteristics of lightning current amplitude in papers written on the issue; Methods used for conducting field investigations of lightning current in Japan; Results of lightning current measurement using magnetic links on transmission lines.
- Published
- 1998
- Full Text
- View/download PDF
29. The Asia-Pacific context for technology management.
- Author
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Liker, Jeffrey K., Gibson, David V., and Wu, Yenchun
- Subjects
TECHNOLOGY ,ECONOMIC history - Abstract
Describes the technology management in the Asia-Pacific region. Statistical portrait of the Asia-Pacific economies; Research issues concerning the management of technology in the region; Details on the Japanese technology management.
- Published
- 1998
- Full Text
- View/download PDF
30. Guest Editorial Special Section on the 2018 International Symposium on Semiconductor Manufacturing.
- Author
-
Moriya, Tsuyoshi
- Subjects
SEMICONDUCTOR manufacturing ,SEMICONDUCTOR devices ,CONFERENCES & conventions ,SEMICONDUCTOR technology ,CURRENT good manufacturing practices - Abstract
Since its beginning in 1992 in Japan, International Symposium on Semiconductor Manufacturing (ISSM) has provided unique opportunities to share the best practices of semiconductor manufacturing technologies for professionals. At the symposiums, semiconductor manufacturing professionals discussed the technologies developed to meet the worldwide requirements for advanced manufacturing. It is becoming crucial to re-examine semiconductor manufacturing in terms of fundamental principles to improve the performance of semiconductor devices. Moreover, utilizing artificial intelligence technologies to improve semiconductor manufacturing have become a new challenge. These manufacturing technology challenges are showing the need for drastic revolutionary concept and stronger collaborative efforts to find solutions to the precompetitive challenges. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Special Section on the International Symposium on Semiconductor Manufacturing.
- Author
-
OTSUKA, NOBUHIRO and UCHINO, TOSHIYUKI
- Subjects
CONFERENCES & conventions ,SEMICONDUCTOR industry ,MANUFACTURING processes - Abstract
Information about the 17th International Symposium on Semiconductor Manufacturing held in Tokyo, Japan from October 27 to 29, 2008 is presented. Highlights include the discussion on the yield enhancement and clean technology, which has been considered an essential technical area of semiconductor manufacturing. Further, it was also said to have given emphasis on the new dry and wet combined equipment having the capacity of addressing the issues on process performance and cost-control.
- Published
- 2009
- Full Text
- View/download PDF
32. Guest Editorial Special Issue on Electrical Discharges in Vacuum.
- Author
-
Morimiya, Osami and Struve, Kenneth W.
- Subjects
CONFERENCES & conventions ,ELECTRIC insulators & insulation ,MICROELECTRONICS ,VACUUM ,ASSOCIATIONS, institutions, etc. - Abstract
Information about the twenty-second International Insulation in International Symposium on Discharge and Electrical Insulation in Vacuum (ISDEIV) which was held in Marsue, Japan on September 25-29, 2006 is presented. The symposium was hosted by the Vacuum Society of Japan. The conference was significantly altered to include developing vacuum microelectronics devices, surface modification technologies and other new vacuum plasma applications.
- Published
- 2007
- Full Text
- View/download PDF
33. 36th European Conference on Optical Communication [ECOC 2010 Conference Report].
- Author
-
NERI, FABIO
- Subjects
CONFERENCES & conventions ,OPTICAL communications ,TRADE shows - Abstract
The article focuses on the highlights of the 36th annual European Conference on Optical Communication (ECOC) held in Turin, Italy in September 2010. The goals of ECOC include the dissemination of new research results, the education of engineering and business leaders and the exhibition of optical fiber communication and networking products. Speakers at the event included Masataka Nagazawa of Tohoku University in Japan, who discussed developments related to optical communication technologies.
- Published
- 2011
- Full Text
- View/download PDF
34. Development of Structures for ITER Toroidal Field Coil in Japan.
- Author
-
Iguchi, M., Chida, Y., Takano, K., Kawano, K., Saito, T., Nakajima, H., Koizumi, N., Minemura, T., Ogata, H., Ogawa, T., Oosemochi, K., Niimi, K., and Tokai, D.
- Subjects
GAS tungsten arc welding ,GAS metal arc welding ,TOKAMAKS ,FRACTURE toughness - Abstract
JAEA has conducted qualification and rationalization activities in Japan since March 2009 in order to rationalize manufacturing procedure of ITER toroidal field coil (TFC) structures. These following activities has been performed: qualification of structural materials and qualification and development of welding procedure according to the JSME code constituted for fusion devices, demonstration of the manufacturing method and procedures through manufacture of 1 m mock-ups and full-scale segments of TFC structure. From results of these activities, JAEA confirmed quality of materials and weld joints of gas tungsten arc welding and gas metal arc welding. In addition, JAEA obtained knowledge of welding deformation of actual TFC structures. This paper describes results of these qualification and development activities for ITER TFC structure. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
35. Final Design of the Quench Protection Circuits for the JT-60SA Superconducting Magnets.
- Author
-
Gaio, Elena, Maistrello, Alberto, Coffetti, Alberto, Gargano, Teresa, Perna, Mauro, Novello, Luca, Coletti, Alberto, Matsukawa, Makoto, and Yamauchi, Kunihito
- Subjects
DIRECT currents ,TOKAMAKS ,HYBRID integrated circuits ,CONCEPTUAL design ,ELECTRIC potential - Abstract
This paper describes the detailed design of the quench protection circuits (QPCs) for the superconducting toroidal field (TF) and poloidal field (PF) magnets of the satellite tokamak JT-60SA, which will be installed in Naka, Japan. The nominal currents to be interrupted and the maximum reapplied voltages are 25.7 kA and 2.8 kV for the TF QPCs and 20 kA and 5 kV for the PF QPCs. The innovative solution proposed in the QPC design is based on a hybrid circuit breaker (CB) composed of a mechanical bypass switch for conducting the continuous current, in parallel to a static CB for current interruption. The main choices of the final design are presented and discussed, either to confirm or to update and complete the study performed at the conceptual design level. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
36. Characteristics of Negative Flashes With Multiple Ground Strike Points Located by the Japanese Lightning Detection Network.
- Author
-
Matsui, Michihiro, Michishita, Koji, and Yokoyama, Shigeru
- Subjects
LIGHTNING ,ELECTROMAGNETIC compatibility ,ELECTROMAGNETIC waves ,FAULT location (Engineering) ,PARTIAL discharges ,OVERVOLTAGE - Abstract
Approximately 50% of natural lightning flashes make multiple contacts on the ground. Lightning-induced voltage by nearby lightning stroke is the major cause of overvoltage. The electromagnetic waves emitted by lightning flashes with multiple ground strike points (GSPs) increase new risks to damage electronics information devices located in the vicinity of the GSPs. Therefore, it is very important for electromagnetic compatibility engineering to clarify the characteristics of lightning flashes with multiple GSPs. We have observed lightning discharges over the whole area of Japan detected by the Japanese Lightning Detection Network (JLDN). Specifically, we analyzed negative cloud-to-ground (CG) flashes observed by JLDN within 80 km of Sagamihara in summer. We investigated the median location accuracy of the JLDN in the observation area to evaluate characteristics of spatial distribution of subsequent strokes hitting the GSPs. The median location accuracy varied between 0.2 and 0.4 km in the observed area. The mean multiplicity of negative CG flash observed by JLDN was 3.5. The average inter-stroke interval of new ground contact (NGC) strokes was longer than that of pre-existing channel (PEC) strokes. The ratio of peak current to the first return stroke was higher in the NGC than that in the PECs. Some of flashes hit the ground at several points. The mean number of GSPs was 2.0 per flash, with the mean number of 1.6 subsequent strokes per a GSP. Furthermore, the number of strokes per a GSP has not been previously reported. We also observed that the subsequent strokes altered between different GSPs. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
37. A Relaxed Matrix Inversion Method for Retrieving Water Constituent Concentrations in Case II Waters: The Case of Lake Kasumigaura, Japan.
- Author
-
Yang, Wei, Matsushita, Bunkei, Chen, Jin, and Fukushima, Takehiko
- Subjects
MATRIX inversion ,ARTIFICIAL satellites ,COMPOSITION of water ,REMOTE sensing ,REFLECTANCE spectroscopy ,AERIAL photography in geography - Abstract
The matrix inversion method (MIM) is an effective algorithm for estimating water constituent concentrations in case II waters. To apply this method, appropriate and accurate specific inherent optical properties (SIOPs) for each constituent in water are essential. However, many routine observations of lake water quality do not in fact provide SIOPs, thus limiting the application of the MIM. In this paper, an alternative MIM method based on linear matrix inversion theory was proposed to relax the requirement of SIOPs measurement. For this, so-called ESIOPs (Estimated SIOPs) were first derived by an unusual application of MIM based on adequate calibration samples; then the water constituent concentrations for the whole study area were retrieved by the standard application of MIM based on the derived ESIOPs. For each calibration sample, measurement of the reflectance spectrum and corresponding water constituent concentrations, which can be obtained from periodical satellite data and routine field surveys, is required. The performance of the proposed method was evaluated using the simulation data from Hydrolight and three MEdium Resolution Imaging Spectrometer Instrument (MERIS) images. The results showed that this method yielded satisfactory estimations of the water constituent concentrations for the noise-contaminated simulation data sets. For MERIS data in our study area (Lake Kasumigaura, Japan), the average bias (mean normalized bias or MNB) and relative random uncertainty (normalized root mean square error, or NRMS) were in the range of -11.2% to 3.4% and 4.8% to 29.7% for each water constituent concentration. These findings imply that the algorithm proposed in this study is theoretically reasonable and practically applicable. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
38. Game of Risk Communications—The Case of a Japanese Carmaker.
- Author
-
Umehara, Eiichi and Ohta, Toshizumi
- Subjects
AUTOMOBILE industry ,RISK communication ,DECISION making ,GAME theory ,NASH equilibrium ,SENSITIVITY analysis ,TRAFFIC accidents - Abstract
In this paper, game models for risk information disclosure—which interpret user payoff structures according to March and Simon's theory of satisficing decision making and interpret a carmaker's payoff structures according to Tversky and Kahneman's cumulative prospect theory—are developed. This risk information disclosure game is used to analyze the recall of products by a carmaker. The transitions made from one game to another correspond to the carmaker's subjective risk assessment of the probability that nondisclosure will be discovered by the user. The user's claims hasten the carmaker's change from a nondisclosure game to another kind of game. The role of a guardian agent in fault information disclosure is examined. The presence of an agent caused the carmaker playing the game to change from nondisclosure to disclosure mode. From the viewpoint of operational cost, the risk information disclosure in an environment where a permanent guardian agent is always active is considered to be effective in achieving good risk communications. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
39. Test Results of a 30 m HTS Cable for Yokohama Project.
- Author
-
Masuda, T., Yumura, H., Ohya, M., Ashibe, Y., Watanabe, M., Minamino, T., Ito, H., Honjo, S., Mimura, T., Kitoh, Y., and Noguchi, Y.
- Subjects
ELECTRIC power ,TEMPERATURE measurements ,HIGH temperature superconductors ,ELECTRIC cables ,ELECTRIC power transmission ,ELECTRIC fault location ,THERMODYNAMIC cycles - Abstract
HTS cable demonstration project supported by Ministry of Economy, Trade and Industry (METI) and New Energy and Industrial Technology Development Organization (NEDO) has started in Japan. The target of this project is to operate a 66 kV, 200 MVA HTS cable in the live network of Tokyo Electric Power Company in order to demonstrate its reliability and stable operation. The design of the HTS cable with DI-BSCCO has been completed as well as those of a termination and a joint. A 30-meter HTS cable system with terminations, a joint and a cooling system was installed in SEI facility to confirm their design and performance. Various tests as voltage tests, nominal and over current tests, heat cycle tests, heat loss measurements and so on were conducted and it is verified that the cable has good performances as design. This paper describes the design and test results of a 30-meter HTS cable, and discusses required test items of HTS cables. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
40. Optimization of Rotor of Actual IPM Motor Using ON/OFF Method.
- Author
-
Takahashi, Norio, Yamada, Takaya, Shimose, Satoshi, and Miyagi, Daisuke
- Subjects
ROTORS ,PERMANENT magnet motors ,OPTIMAL designs (Statistics) ,MAGNETIC circuits ,TORQUE ,MATHEMATICAL variables ,MOTOR design & construction - Abstract
For the design of an Interior Permanent Magnet (IPM) motor with small torque ripple and large driving torque, the optimal design method called the ON/OFF method is attractive, because a new magnetic circuit, which we could not imagined beforehand, may be obtained. In this paper, a non-parametric optimization technique to find a new magnetic circuit which minimizes a torque ripple and maximizes a driving torque of IPM motor is examined. The effectiveness of the ON/OFF method for the optimal design of a motor is examined by applying it to the design of the verification model of the IPM motor established by the technical committee of IEE of Japan. Factors affecting torque ripple and driving torque of the obtained optimal motor core are also discussed. [ABSTRACT FROM PUBLISHER]
- Published
- 2011
- Full Text
- View/download PDF
41. A 5.8 GHz Integrated CMOS Dedicated Short Range Communication Transceiver for the Korea/Japan Electronic Toll Collection System.
- Author
-
Kwon, Kuduck, Choi, Jaeyoung, Choi, Jeongki, Hwang, Yongseok, Lee, Kwyro, and Ko, Jinho
- Subjects
COMPLEMENTARY metal oxide semiconductors ,RADIO transmitter-receivers ,TOLLS ,INTEGRATED circuits ,QUADRATURE domains ,VOLTAGE-controlled oscillators - Abstract
In this paper, a RF front-end of the 5.8 GHz integrated CMOS dedicated short range communication (DSRC) transceiver for the Korea/Japan electronic toll collection system is presented. The receiver uses low-IF conversion architecture for high sensitivity and low-power consumption while the transmitter uses direct up-conversion architecture for its simple structure and reliability. To solve image problem in the low-IF receiver, 10 MHz IF and 40 MHz IF are chosen for Korean and Japanese DSRC standards, respectively, since they make no image signals exist in image band. A single-quadrature mixer with the proposed transconductor-type quadrature generator in RF signal path is also adopted which has accurate quadrature characteristic in 5.8 GHz frequency. [ABSTRACT FROM PUBLISHER]
- Published
- 2010
- Full Text
- View/download PDF
42. Parallel Computing of Magnetic Field for Rotating Machines on the Earth Simulator.
- Author
-
Nakano, Tomohito, Kawase, Yoshihiro, Yamaguchi, Tadashi, Nakamura, Masanori, Nishikawa, Noriaki, and Uehara, Hitoshi
- Subjects
MAGNETIC fields ,FINITE element method ,ROTATING machinery ,PARALLEL computers ,SUPERCOMPUTERS - Abstract
We developed a parallel computing method of the magnetic field for rotating machines by using the 3-D finite element method (FEM) with edge elements. In this paper, we describe the outline of the developed method and an optimization of the method for the Earth simulator, which is a vector-type parallel supercomputer in Japan. Moreover, the performance of the proposed method running on the Earth simulator is quantitatively clarified. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
43. Mechanical Analysis of the JT-60SA TF Coils.
- Author
-
Nannini, M., Portafaix, C., Decool, P., Dolgetta, N., Zani, L., and Barabaschi, P.
- Subjects
NUCLEAR fusion ,MATHEMATICAL optimization ,PRESSURE ,STRAINS & stresses (Mechanics) - Abstract
The mission of the JT-60SA Tokamak, which will be built in Japan, is to contribute to the early realization of fusion energy in support and supplement of the ITER program. The JT-60SA project is part of the broader approach for fusion energy. In 2008, due to a design change of the TF cross section, and following the redefinition of the global JT-60SA features, mechanical analyses were redone. The first 2D and 3D mechanical analyses were performed on the current TF design, providing useful information on the pros and cons of the new design. For the 2D analysis, the critical area of the inner leg cross section in the location of the equatorial plane was meshed to study the effect of in plane loads. The analysis includes checking the peak field applied to the conductors and the stress on each of the components of the winding pack cross section, in particular in the insulation which is a critical component. The stress in winding pack cross section is due to the accumulation of cool down strain, "in plane" Lorentz forces and to the quench pressure. Both magnetic and mechanical analyses are performed with the ANSYS V11.0 code. In this paper, we present the main steps of the 2D and 3D FEM calculations which were developed by CEA and used in the following analyses. Associated statements concerning possible TF design optimization with respect to cost, feasibility or risk are also presented. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
44. Design and Construction of FFAG Magnets for the ERIT System at KURRI.
- Author
-
Okabe, Kota, Uesugi, Tomonori, Kuriyama, Yasutoshi, Planche, Thomas, Lagrange, Jean-Baptiste, Ishi, Yoshihiro, Sakai, Izumi, and Mori, Yoshiharu
- Subjects
PARTICLE accelerator design & construction ,MAGNETS ,NEUTRON sources ,NEUTRON capture therapy ,MAGNETIC fields - Abstract
As an intense neutron source for the boron neutron capture therapy system, a FFAG storage ring with Energy/emittance Recovery Internal Target (ERIT) has been developed in the Kyoto University Research Reactor Institute (KURRI). In order to develop storage ring for ERIT scheme, the spiral sector and radial sector FFAG rings were designed and compared about performance in ERIT system. The 3-dimensional magnetic fields of these magnets were calculated with the field analysis code, TOSCA. The pole shape of magnet was carefully optimized checking the betatron tune. Tunes were computed by means of tracking simulations in field maps based on TOSCA models. In this paper, the FFAG magnet design for ERIT system and the construction of FFAG ring in KURRI are described. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
45. Analysis of Quench Propagation in the ITER Poloidal Field Conductor Insert (PFCI).
- Author
-
Zanino, Roberto, Bonifetto, Roberto, and Richard, Laura Savoldi
- Subjects
SUPERCONDUCTORS ,NIOBIUM ,NUCLEAR fusion ,SUPERCONDUCTING magnets ,ELECTRIC coils - Abstract
We analyse the issues of quench propagation in the NbTi Poloidal Field Conductor Insert (PFCI), recently tested at JAEA Naka, Japan. The simulation tools Mithrandir, already validated against data from previous Nb3Sn Insert Coils, and M3, implementing a more detailed thermal-hydraulic description of the CICC cross section, are used. The results of the analysis are reported in the paper and compared with experimental data, with particular attention to NbTi versus Nb3Sn features and to the effects of different model assumptions. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
46. Intermag Asia 2005 Publication Chairs' Preface.
- Author
-
Tarnopolsky, Giora, Muraoka, Hiroaki, and Matsui, Masaaki
- Subjects
CONFERENCES & conventions ,MAGNETICS ,ARCHIVES ,MAGNETISM ,INTELLECTUAL cooperation - Abstract
The article presents information on the International Magnetics Conference 2005 held in Nagoya, Japan. The conference was of outstanding scientific and technical quality. Altogether there were 1058 presentations given at the conference. These were strictly selected by the Program Committee from the 1527 digests and nominations that were submitted. After the conference, a total of 817 manuscripts were submitted for consideration for publication in this volume. This was a much heavier burden than anticipated for the editors of Intermag 2005. In order to avoid any delays, two publications teams were set up: Higashi and Nishi.
- Published
- 2005
- Full Text
- View/download PDF
47. Lightning Electric Field Characteristics Associated With Transmission-Line Faults in Winter.
- Author
-
Ishii, Masaru and Saito, Mikihisa
- Subjects
ELECTROMAGNETIC fields ,ELECTRIC fields ,MECHANICAL engineering ,POWER transmission - Abstract
In this paper, lightning electric field waveforms related to notable power transmission-line faults in winter along the coastline of the Sea of Japan were examined. Most of the wave- forms of the observed electromagnetic field changes, which were more than five times as intense as an average negative return- stroke fields, are inferred to be associated with upward lightning discharges. Lightning discharges that produce such characteristic waveforms are termed ground-to-cloud flashes, and properties of the associated electric field waveforms are examined. These lightning discharges in winter distribute around the coastline of the Sea of Japan in different ways depending on their polarities. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
48. Installation and Test Programme of the ITER Poloidal Field Conductor Insert (PFCI) in the ITER Test Facility at JAEA Naka.
- Author
-
Nunoya, Yoshihiko, Takahashi, Yoshikazu, Hamada, Kazuya, Isono, Takaaki, Matsui, Kunihiro, Oshikiri, Masayuki, Nabara, Yoshihiro, Hemmi, Tsutomu, Nakajima, Hideo, Kawano, Katsumi, Tsutsumi, Fumiaki, Takano, Katsutoshi, Uno, Yasuhiro, Koizumi, Norikiyo, Okuno, Kiyoshi, Baker, William, Salpietro, Ettore, Rajainmaki, Hannu, Sborchia, Carlo, and Mitchell, Neil
- Subjects
ELECTRICAL conductors ,MAGNETIC circuits ,SUPERCONDUCTIVITY ,JOINTS (Engineering) - Abstract
ITER PFCI has been manufactured in the Europe and installed into the ITER Test Facility in Naka, Japan. The conductor is NbTi cable-in-conduit conductor with thick square stainless steel jacket and almost identical with the design of the ITER PF coils. The main objective of this test is the characterization of the conductor and joints at the conditions relevant to the ITER PF coil operation. Intermediate joint is located in the winding at relatively high field to examine its performance. The main items in the PFCI test program are thermo-hydraulic test, DC mode test, cyclic test and pulse mode test. The PFCI and CSMC were successfully cooled down to cryogenic temperature within 450 hours. The test of the PFCI was performed from May to August 2008. The key technology of the installation, the test methods and procedures, and some preliminary results of cool-down are described in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
49. Improvement of the Voltage Dependence of High-Voltage AC—DC Transfer Differences at the NMIJ.
- Author
-
Fujiki, Hiroyuki
- Subjects
CALIBRATION ,PHYSICAL measurements ,CASCADE converters ,ELECTRIC potential ,STANDARDIZATION ,ELECTRIC resistors ,HEATING ,ELECTRIC insulators & insulation ,PERMITTIVITY - Abstract
A new ac-dc comparator system of 20-1000 V has been developed at the National Metrology Institute of Japan (NMLJ) for the calibration of ac-dc thermal voltage converters (TVCs), which are used as national ac-dc transfer standards. The ac-dc transfer differences of high-voltage transfer standards were evaluated by a traditional step-up procedure. The voltage dependence of the ac-dc transfer difference was observed in the earlier step-up procedures over 300 V, as reported by the latest international intercomparison. The experimental results for high- voltage TVCs with several different range resistors at the NMU suggest that the voltage dependence may primarily be caused by input connectors of range resistors and the change in the resistance value of the resistor and TVC modules due to heating from resistors. This paper describes the voltage dependence improvement of ac-dc transfer differences over 300 V at the NMLJ. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
50. Strategic Capabilities and Radical Innovation: An Empirical Study in Three Countries.
- Author
-
Di Benedetto, C. Anthony, DeSardo, Wayne S., and Song, Michael
- Subjects
INNOVATION management ,REGRESSION analysis ,TECHNOLOGICAL innovations ,INFORMATION technology ,MARKETING ,BINOMIAL distribution - Abstract
This paper examines strategic capabilities as drivers of the development and launch of radical innovations. We construct a theoretical framework relating five strategic capabilities (mar- keting, market linking, technology, information technology, and management-related capabilities) to radical innovation. From this framework, we derive hypotheses concerning a division's propensity to engage in radical innovation. Using empirical data derived from a research study of 376 firms in the United States, Japan, and China, we apply analysis of variance and negative binomial distribution (NBD) regression techniques to test our hypotheses. We find evidence that, overall, technology and information technology capabilities are significantly and positively related to radical product innovation. We also find some significant differences among the three country samples concerning drivers of radical innovation. Marketing capability is more significantly and positively related to radical innovation in the United States than in Japan; and, in China, the only capability that is significantly and positively related to radical innovation is technology. All of the findings completely or partially support our research hypotheses. We conclude with a discussion of the managerial implications of our findings, and directions for future research. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
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