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Volume 127, Issue 1
Displaying 1-14 of 14 articles from this issue
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Special Issue on Technology 2007 : Reviews & Forecasts
Special Issue Review
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Yukihiko Sato2007 Volume 127 Issue 1 Pages 2-3
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSEngineering education is significantly changing in recent years. This article describes contemporary topics related to the engineering education. First of all, introduction of the Japanese accreditation system for engineering education and its influence are explained. New methods for engineering education using information technology and their usefulness are summarized. Finally, the social responsibility of engineers and problem of decrease in the interest of young people in the engineering are pointed out.View full abstractDownload PDF (199K) -
Katsumi Hattori, Masashi Hayakawa2007 Volume 127 Issue 1 Pages 4-6
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSDespite its extreme importance and years of efforts, practical short-term earthquake prediction still remains to be achieved in future. However, earthquake- related electromagnetic phenomena are recently considered as a promising candidate for short-term earthquake prediction. There have been accumulated a lot of evidences of precursory signatures in a wide frequency range (DC-VHF). In this paper, the state of the art and research progress of seismo-electromagnetics are summarized.View full abstractDownload PDF (1004K) -
Ken Yukimura2007 Volume 127 Issue 1 Pages 7-8
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThe plasma-ion processing of three-dimensional components tends to expand various fields from microelectronics to environmental industries. The recent trend is not only surface modification by thin film prepared by reactive deposition using a metallic plasma source generated in reactive gases, but also deep layer ion-penetration of the component using thermal diffusion. The substrates are immersed in the plasma and are pulse-biased with a low voltage. This article introduces the plasma-ion processing for three dimensional components, and its merits and drawbacks, and examples of the applications are also shown.View full abstractDownload PDF (186K) -
Redy Mardiana, Toshio Iguchi, Tomoo Ushio, Zen-Ichiro Kawasaki2007 Volume 127 Issue 1 Pages 9-12
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThis paper describes a novel single-frequency algorithm to estimate the vertical profiles of drop size distribution (DSD) of rainfall. The algorithm, which does not rely on the surface echoes, is proposed to be adopted in the TRMM precipitation radar (PR). The basic principle is to seek the DSD that can not only reproduce the radar reflectivity profiles at a given wavelength but also the path attenuation that is used for the constraints prior to deriving the DSD profile. The algorithm adjusts the estimate of attenuation factor at the surface iteratively until this estimate retrieves the reflectivity factor that is equal to the original measured reflectivity factor. The algorithm is applied to the spaceborne TRMM/PR radar data. The comparison between the results derived from the Hitschfeld-Bordan (HB) method, Surface Reference Technique (SRT), current TRMM method, and the proposed method is presented and discussed.View full abstractDownload PDF (304K) -
Kazuhiko Horioka2007 Volume 127 Issue 1 Pages 13-14
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSHigh energy density plasmas driven by pulse power devices are of interest from the point view of their application to formations of extreme conditions. Dense plasmas are produced using pulse-power driven exploding wire discharges in water. Experimental results show that the plasma is tamped and stabilized by the surrounding water and it cylindrically evolves through a strongly coupled state. A shock-heated, high temperature plasma is produced in a compact pulse power device. Results show that extremely strong shock waves can be produced in the device. At low initial pressure condition, the shock Mach number reaches 250 that exceed well a criterion of radiative shock waves.View full abstractDownload PDF (586K) -
Toshiki Nakano2007 Volume 127 Issue 1 Pages 15-16
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSResent trends on the resarch activities of electrical-discharge-related technologies are summarized as well as the policies of the technical committee on electrical discharges (TC-ED) of IEEJ. First, the present situation of electrical discharge research is mentioned by referring to the major subjects which TC-ED is responsible to cover. As an example of the increasingly widespread use of electrical dischrge technologies, vacuum electrical insulation in a neutral beam injection system of the Interrnational Thermonuclear Experimental Reactor (ITER) device is presented.View full abstractDownload PDF (437K) -
Shinichi Takahashi2007 Volume 127 Issue 1 Pages 17-18
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThe technology trends in light applications and visual science are introduced in field such as medical treatment, media devices for information processing of visual sense, light sources and their measurement, application of infrared light, and advanced lithography.View full abstractDownload PDF (212K) -
Katsunori Shida2007 Volume 127 Issue 1 Pages 19-20
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSInstrumentation and measurements play a very important role for the research and development in the science and engineering fields. Recently the objectives of instrumentation have expanded to not only the industrial and scientific requirement, but also needs in all fields of social life including medical and welfare, environment, and disaster and security, etc. In recent years, intelligent and multifunctional measurements have been also studied in imitating the sensing functions of the human.View full abstractDownload PDF (413K) -
Naohiro Hozumi2007 Volume 127 Issue 1 Pages 21-23
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThis article reports the state-of-art of TC-DEI ( Technical Committee of Dielectrics and Electrical Insulation of IEEJ) activities. The activities are basically based on those of 8-10 investigation committees under TC-DEI. Recent activities are categorized into four functions. We are trying to expand our field of activity. Relating three topics are described in the article.View full abstractDownload PDF (410K) -
Yasuzo Tanaka2007 Volume 127 Issue 1 Pages 24-26
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSProgress in fuel cell technologies is reviewed for this special issue. In the diversified society, the fuel cell technology is a significant and most promising field. The fuel cell technologies provide many variations for our uses and possibilities for our lives. Especially, some technological battles in the PEFC, SOFC and DMFC are excitedly interested us.View full abstractDownload PDF (483K) -
Satoshi Sugimoto2007 Volume 127 Issue 1 Pages 27-28
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThe aerosol deposition method (ADM) is effective for the preparation of thick films with high deposition rate. We applied this method to fabricate NiZn ferrite or Sm-Fe-N films, which are used for microwave absorbers or permanent magnets, respectively. In this article, the magnetic properties of Sm-Fe-N thick films fabricated by the ADM are introduced and the possibility of the ADM for the fabrication process with high deposition rate is discussed.View full abstractDownload PDF (383K)
Special Issue Paper
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Rudi Kurnianto, Yoshinobu Murakami, Masayuki Nagao, Naohiro Hozumi, Yo ...2007 Volume 127 Issue 1 Pages 29-34
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSA nano-composite material of magnesium oxide (MgO) added to a low-density polyethylene (LDPE) was subjected to electrical tree breakdown investigation. The LDPE without nano-fillers was lower in breakdown voltage than the LDPE added with nano-fillers. The breakdown voltage was increased by increase of nano-filler concentrations in LDPE. This result much coincided with the result on tree inception voltage which was increased when the concentration of filler in LDPE was increased. It is considered that fillers would create such an obstruction to the tree bridging the counter electrode. However, even the tree had bridged the plate electrode; the breakdown was not always immediately to occur. There would be so-called time-lag between “bridging” and “final breakdown”. The time-lag to breakdown was increased with the nano-filler concentrations in LDPE. It is considered that the polymer nano-composites are more resistive against partial discharges than their base material.View full abstractDownload PDF (1881K)
Paper
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Influence of Non-uniform Distribution of Grains on Noise Absorption Characteristics of ZnO VaristorsMahmudul Kabir, Masafumi Suzuki, Noboru Yoshimura2007 Volume 127 Issue 1 Pages 35-40
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSNoise absorbing process of Zinc Oxide (ZnO) varistors was analyzed by using equivalent circuit of the sample varistors. Equivalent circuit for the ZnO varistor was proposed by considering the microstructure of a special type of varistor made for the experimental purpose. We considered every grain between the internal electrodes and made an equivalent circuit. The circuit's parameters were determined by PSpice circuit simulator. We regarded a portion of the internal electrode and made a uniform model with a non-uniform model. A dc motor was connected with these models in parallel to investigate the effects of the non-uniformity of the ZnO grains in noise absorbing characteristics of a varistor. Comparing to the uniform model, resonance occurred in the non-uniform model while absorbing noise, and thus the absorption of noise of the model was deteriorated. Transient current was calculated for each grains of these models to investigate the effect the deterioration of noise absorbing characteristics. Localized current was found in the non-uniform model when resonance occurred to absorb transient voltage from our calculations.View full abstractDownload PDF (1032K) -
Hisashi Ishikawa, Katsumi Hattori, Ichiro Takahashi, Yoichi Noda, Tosh ...2007 Volume 127 Issue 1 Pages 41-47
Published: 2007
Released on J-STAGE: April 01, 2007
JOURNAL FREE ACCESSThe variations of geoelectrical potential differences in Hakuba area, Nagano Prefecture, Japan have been investigated. The noises originated from the DC-driven trains were found to contaminate the natural geoelectrical potential data. The most intense influence of trains occurred when the train was running nearby measuring dipoles. The gradient of the potential was deflected towards the railways and/or the position of the train, exhibiting a certain correlation between the power supply data at substation and the geoelectrical potential data at measuring sites. Extracting the high correlation part (r > 0.7), “idealized” train noise can be computed by the least square method. The reduction of train noise by more than 60 % was achieved by subtracting the idealized noise from observed data.View full abstractDownload PDF (2268K)
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