COMMISSION E 02

COMMISSION E : Electromagnetic Noise and Interference (Nov. '98 - Oct. '01)

Edited by Zen Kawasaki

Activities of Commission E in Japan can be roughly categorized into major six subjects, and those are lightning physics, Sprites/Elves, Electromagnetic waves related with earthquakes, Electromagnetic noise in wireless communications, Electromagnetic noise related with printed circuit boards and EMC related with electrical power engineering. The first three subjects are natural phenomena, and the latter three seem to be man made issues. That is why this Activity Report consists of six sessions from E1 to E6.

E1. Lightning Physics

One of the most current topics in the research field of lightning physics is the VHF/UHF source location, which is believed to highly depend on the charge distribution inside the thundercloud. To make VHF/UHF source location two different principles are well known. The one is the Time of Arrival (TOA) technique, and the experimental system named LDAR (Lightning Detection and Ranging) has been operating in U.S. The other one is based on the technique of interferometory, and has been accomplished as an operational and commercially available system by a French organization. Under this situation, University of Tokyo lightning research group has been concerned with the TOA technique, and Lightning Research Group of Osaka University (LRGOU) has been engaged in the interferometers. Both groups have been conducting filed campaigns independently at the Hokuriku Coast, where they can observe the lightning activity during winter thunderstorms. Lightning activity during winter thunderstorms was discovered in mid 70s, and since then many related researchers have been paying their attention on its unique features. Both UT and OU groups are quite vigorous and productive. UT group has presented the possible interpretations on the initiation of lightning discharges during winter thunderstorms by observing with their TOA system. LRGOU has partly revealed the positive charge distributions, which can contribute positive cloud-to-ground discharges with long continuing currents.
Optical observation of lightning flashes is another interesting issue in this filed. Central Research Institute of Electrical Power Industry (CRIEPI) has contributed for developing an optical measuring system based on CCD matrix with high speed A/D converters for all CCD components. They name this ALPS (Automatic Lightning Progression measuring System), and the function is equivalent to a digital flaming camera and/or a streak camera. They have achieved the sub micro-second time resolution, and they have mainly operated this for the upward triggered lightning from tall constructions. The main objective of their observations is to understand the mechanism of upward initiated lightning discharges to design the protection of power apparatus. ALPS are widely operated by other organizations, like Gifu University, and Suzuka Technical Collage. CRIEPI and Gifu University have collaborated campaigns with Florida University. In Florida they have been concerned with the rockets triggered lightning instead of upward initiate lightning from tall constructions.
LRGOU has been concerned with TRMM/LIS (Tropical Rainfall Measuring Mission/ Lightning Imaging Sensor) as one of principal investigators. LRGOU has discovered following three items. The first issue is lightning activity during El-Nino period over west Indonesia is higher than the normal period instead of less precipitation. The second issue is the immigration of winter thunderstorm activity over the Pacific Ocean at mid latitude. The last issue is that the relation ship between lightning activity and snow depth observer by TRMM PR is uniform. The analysis of TRMM/LIS observations are on going.
The Fifth International Workshop on Physics of Lighting (5^th IWPL) was held from September 10 through 13, 2001, in Nagoya. This workshop was organized by Prof. Nakamura, Nagoya Institute of technology.

(Z.-I. Kawasaki)

E2. Sprites/elves-related study in Japan

E2-1 Optical Observations
Japanese groups have been conducting ground-based and aircraft observations since 1995. Tohoku University developed a hi-speed multi-anode array photometer (MAP) that has 16 channels in vertical direction. Using 2 MAPs with two different color filters, the electron energies producing sprites and elves were estimated. A hi-speed CCD camera, a near-infrared CCD camera and an image-intensified CCD camera were also operated in US and Japan. A hi-speed photometer operated by Tohoku University found elves in 1995. Japanese groups also took important roles in discoveries of sprites and/or elves in Japan, Australia and the Mediterranean. The stored data sets are now under detail analysis
Projects:
Colorado (1995 1999): Tohoku University
The international observation campaign has been conducted since 1994 at Yucca Ridge Field Station (YRFS) in Colorado, US. Tohoku University group participated in the campaign in 1995 1999 with several optical instruments as well as an ULF receiver.
Japan (1998 present): Tohoku University, University of Electro-Communications
Tohoku University started the ground based optical observation at two sites in Japan in December 1998. Every winter season activity of sprites and elves was confirmed.
Australia (1996-present): Osaka University
International observation team including New Zealand, Australia and Japan found sprites in Australia during a summer lightning campaign.
Mediterranean (1999): ISAS
The Leonid meteor shower campaign using an aircraft was conducted by an international science team in November 1999. Japanese scientist caught some sprites and elves with a high resolution TV camera over the Mediterranean Sea.
Results:
Discovery of elves (1995)
Four channel hi-speed photometer found new optical emission appearing with a horizontal extent over 200 km.
Time delay of optical emissions from causative CG
Hi-speed measurement with photometers revealed the relationship between the time delay of sprites emissions from the causative cloud to ground (CG) discharge. According to the result, the sprites can be classified into three types.
Vertical motion of sprites
MAP data showed that the appearance of sprites and vertical motion of sprites are closely related.
Quantitative measurements of luminosity with photometers
Well-calibrated photometers enable us to examine the absolute luminosity of optical emissions precisely, suggesting 1000 times as bright as what we considered before.
Height estimation of elves
Assuming thin optical layer of elves, the emission height are calculated precisely to be ~90 km.
Characteristics of sprite hal
Characteristics of sprite halo , such as dimensions, luminosity, motion and color, were investigated in detail for the first time with photometric and imaging data. Estimation of electron energy
Measurement by MAPs with two broad band filters enable us to estimate the electron energy of sprites, elves and sprite halo with a high temporal resolution. The results show sometimes over 15 eV for sprites.
Discovery of sprites in Australia (1997)
Sprites were imaged outside North America for the first time in summer Australia.
Discovery of sprites and elves induce by winter storms (1998)
Winter sprites and elves were found for the first time in Japan. Also the precise height and horizontal distribution of elements for one sprites event were calculated by triangulation from two sites.
Discover of sprites and elves over the Mediterranean (1999)
From aircraft flying for the Leonid campaign, activities of sprites and elves were identified in the European area for the first time. The elves imaged showed considerably long life, 10 times of normal elves life times.
Discovery of sprites appearing over the Pacific Ocean (2000)
During the winter sprites campaign in Japan sprites were observed at a distance of >500 km from the closest coast of Japan. Their feature seems something different from sprites near the west cost of Japan in the same season.
Morphology of summer and winter sprites
Characteristics of sprites and elves in summer US and in winter Japan were compared carefully. Sprites features look quite different, though no clear difference was found for elves.

E2-2 Electromagnetic Wave Observations
Electromagnetic measurements in the frequency range of VLF, ELF and ULF have been conducted by two Japanese groups.
Projects:
Colorado (ULF: 1995 - 1999): Tohoku University
During the summer campaigns at YRFS in Colorado, a set of searchcoil magnetometer for ULF waves were employed.
Japan (VLF: 1998- present, ELF 2001 - present): University of Electro-Communications, Tohoku University
VLF receivers have been operated in Japan continuously by Univ. Electro-Communications. The Schumann resonance (~8Hz) in ELF range is recorded by a searchcoil magnetometer (the same type installed at Syowa) installed at Onagawa observatory in Miyagi by Tohoku University.
Antarctica (2000 - present):
ELF searchcoil magnetometer systems installed at Syowa station, Antarctica, started data acquisition in 2000. The sensor has sensitivity in the frequency range of 0.5 150 (or 400) Hz and the sampling rate is 1 kHz (or 400Hz).
Results:
Determination of location for CG producing Q-burst
Using Q-burst data obtained by ELF receiver at Syowa and at Onagawa, the location of CG that produces sprites can be determined by triangulation. The accuracy is ~400 km or better.
Estimation of charge moment
Charge moments of sprites occurring in Japan, US and other regions in the world, has been derived from ELF observation in Japan and Antarctica.
Discovery of ULF emissions associated with sprites
ULF recording in the summer observation campaign at YRFS, Colorado resulted in finding of transient ULF waves induced by sprites-related discharge phenomena.

E2-3 Numerical Simulation
Two groups in Japan have performed numerical simulations to investigate the mechanisms of sprites, sprite halo and elves.
Projects:
Full wave (1996 present): Kanazawa University
Using a workstation network linking several tens of machines, the full wave simulation has been conducted.
Quasi electro static model (2001 present): Tohoku University
Numerical simulation based on the Quasi electrostatic model has been started.
Results:
Full wave simulation
Considering magnetic filed effect at the ionospheric height, the calculation suggests modulation of elves form. The dynamics of the sprite halo were also reproduced.
- Seasonal change of sprite halo feature
Effect of vertical profile of electron density in summer and winter seasons are examined, suggesting height variation of optical emissions.
E2-4 Summary of International Collaboration
In many cases sprites/elves study has been carried out by international collaboration. Here we summarize the projects and participated universities / institutes working with Japanese groups for sprites/elves research.
Projects:
Colorado Summer Campaign
FMA research Inc., Stanford Univ., Utah State Univ., Univ. Alaska (US), etc
Leonid Meteor Shower observation
NASA, Utah State Univ. (US), etc
Japan Winter Campaign
Stanford Univ. (US)
Student exchange
Utah State Univ. (US)
ELF Observation
Frankfurt Univ., Duke Univ., Univ. Alaska (US), National Chung Kong Univ. (Taiwan)
International Meeting in Japan:
AP-RASC and get together in Sendai [August 2001]
Participants from Germany, Taiwan, Israel, USA, and New Zealand

E2-5 Future Projects
Some future projects of sprites/elves study are now going or under planning in Japan collaborating with many countries.
Spacecraft Missions
- ROCSAT-2/ISUAL (development of instruments: 1998 present)
Taiwan will launch ROCSAT-2 spacecraft with sprites instrument unit (ISUAL) in 2003. Tohoku University is developing Array Photometer which measures vertical motion of sprites/elves/jets at two colors.
- Ground support of spacecraft mission
Space shuttle mission planned by Israel will be launched in July 2002. Japanese groups supports from ground with optical and ELF measurements.
ELF global network
To monitor the global activity of sprites and CG discharges, global network of ELF magnetometrs will be employed continuously in Antarctica, Japan, and Germany.
Polar region
The discovery of winter sprites in Japan strongly suggests the existence of sprites and elves in polar region where aurora appears in the winter season.
Equatorial region
Equatorial area of Asia is one of the most active regions for lightning. Collaborative study with atmospheric radar will be fruitful.

(Y. Takahashi)

E3. EM waves related with earthquakes
After the Kobe Earthquake disaster in Japan (January 14, 1995), Japanese government established the special research programs to investigate short-term earthquake prediction in 1996. These programs included RIKEN (The Institute of Physical and Chemical Research) international frontier research group on earthquakes and NASDA (National Space Development Agency of Japan) remote sensing frontier research, which investigated electromagnetic effects associated with earthquakes. RIKEN project deals with earthquake-related electromagnetic effects occurred under the ground at lower frequency (mainly DC-ULF) phenomena and NASDAs one treats those occurred in atmosphere or ionosphere at higher frequency (VLF, HF). These projects terminated on March, 2002. Over the last five years, especially the last three years, Japan or Japanese researchers did outstanding contributions to earthquake related electromagnetics. First, they set up network station system in Japan. Also sophisticated stations have been installed not only in Japan but also Kamchatka, Russia. Second, RIKEN and NASDA frontier groups organized several international workshops in Japan, two in the last three years and member of these groups organized many sessions in the international conferences. These contributions extend the population with interest in earthquake related electromagnetic phenomena. For example, India started their own frontier project toward the short-term prediction of a large earthquake. And Taiwan will start this September. The third a lot of papers were published.
For these three years, the papers corresponding to moderately large (M6 class) earthquakes such as 1999 Iwate-Ken Nairiku Hokubu EQ, 2000 Izu Islands Swarm, and so on have been published. They have much convincing evidence in ULF geomagnetic changes, abnormal signal changes in VLF transmitter signal, geoelectric potential differences, borehole antenna analysis, Ionsopheric disturbances, and so on.
The important point to find out is to recognition or separation of earthquake related electromagnetic signals in the methodology. In general, electromagnetic signals associated with earthquakes are considered to be weaker and the principle component analysis and polarization analysis have been proposed and developed in ULF geomagnetic approach. As for VLF subionospheric phenomena, significant changes in terminator time are found be appeared a few days before the earthquake. Direction finding method of this field is also highly required.
The perturbation in the ionospheric or the subionospheric data suggests that there are coupling process between Lithosphere, Atmosphere and Ionosphere. That is the forth important findings.
It is expected that a convincing scenarios for the generation of earthquake related electromagnetic phenomena will be proposed soon based on the detailed observation.

(K. Hattori)

E4. EM Noise and Interference in Wireless Communications Systems

As the increase of the demands for mobile communications services, many kinds of wireless communications systems have been developed. In wireless communications systems, a transmitter transmits signal through open space, and a receiver receives it. This means that the transmitter emits the electromagnetic waves in open space, and the receiver receives the electromagnetic waves radiated from any radiation source. As the increase of the wireless communications systems, electromagnetic environment in open space becomes complex, and then electromagnetic compatibility concerning wireless communications systems becomes important issue. Though there are many considerable research activities related with electromagnetic compatibility concerning wireless communications systems, we intend to pay our attention on some special topics to review these three-year's activities and introduce them.

E4-1 Measurements and Statistics of Man-made Noise and Interference
Measurements of radio frequency unnecessary electromagnetic wave (man-made noise or interference) remain to be one of the basic research theme, and the measurements of electromagnetic waves radiated from electrical apparatus, automobiles have been reported in many papers. In addition, since wireless communications systems also become to be noise (interference) sources for another kinds of wireless communications systems, electromagnetic wave emitted from wireless communications systems have been measured. Especially, because of the widespread use of 2.4 GHz band wireless communications systems such as IEEE 802.11b wireless LAN systems and Bluetooth, many efforts to measure the electromagnetic waves radiated from IEEE 802.11b wireless LAN systems, Blutooth and ISM apparatus such as microwave ovens have been done.
In wireless communications systems, since the man-made noise (interference) radiated from electrical apparatus or other wireless communications systems propagates multipath channel from the noise (interference) source to the receiver, the statistics of noise (interference) observed at the receivers point are different from those observed at noise (interference) source point. Propagation of man-made noise (interference) emitted from ISM apparatus or 2.4 GHz band wireless LAN systems through indoor environment has also been discussed in several papers.

E4-2 Effect of Man-made Noise and Interference on the Performance of Wireless Communications Systems
In wireless communications systems, it is well-known that the man-made noise (interference) radiated from electrical apparatus degrades the performance of wireless communications systems. In unlicensed radio frequency bands such as 2.4 GHz radio frequency band, since many kinds of wireless communications systems are operated in same radio frequency bands. Therefore, if these wireless communications systems exist on same place, each wireless communication system degrades the performance other wireless communication system. Although there are many kinds of wireless communications systems subject to man-made noise (interference), IEEE 802.11b wireless LAN systems and Bluetooth have taking a great attention, as it provides the unlicensed wireless communications services using ISM radio frequency band. Several paper reports the effect of man-made noise emitted from microwave ovens on the throughput performance of IEEE 802.11b wireless LAN system and Bluetooth. In addition, some papers discuss the co-existence of IEEE 802.11b wireless LAN system and Blutooth, and reports the effect of mutual interference on the performance of each wireless communication system.

E4-3 Improvement of the Performance of Wireless Communications Systems against Man-made Noise and Interference
As the increase of the wireless communications systems and electrical apparatus, unnecessary electromagnetic wave radiated from electrical apparatus and wireless communications systems becomes more serious problem. In order to establish the electromagnetic compatibility concerning wireless communications systems, several methods have been proposed. For example, in 2.4 GHz band wireless communications systems, in order to establish the co-existence of IEEE 802.11b wireless LAN systems, Bluetooth and ISM apparatus, the propagation control technique using adaptive array antenna have been proposed. Similarly, electromagnetic wave absorber which control the propagation paths of man-made noise, interference and desired signal, have been proposed. These techniques have taking an great attention to overcome the effect of unnecessary man-made noise (interference) and to establish the electromagnetic compatibility in wireless communications systems.

(S. Miyamoto)

E5. EM Noise related with Print Circuit Boards

Excitation mechanisms of radiated emission from high-speed digital systems have been investigated and considerably understood in recent years. Some topics are common mode generation caused by imperfect ground planes in printed circuit boards (PCBs), radiation from bent transmission lines on PCBs, crosstalk from high-speed signal lines to a victim line acting as an EMI antenna, and radio frequency (RF) noise on power supply interconnections such as power bus noise related to resonance of power and ground planes in multilayer PCBs. To suppress the EMI, some noise reduction techniques have been proposed, and have been studied theoretically and experimentally. In this section, these topics on excitation and radiation mechanisms and noise reduction techniques are reviewed.
Electromagnetic susceptibility, or immunity, is another concern related to PCB and electronic system design. Some papers were published on immunity of semiconductor devices and PCBs. In the last part of this section some papers related to device immunity and immunity test methods are reviewed.
Common mode current due to relatively narrow ground return path on a PCB causes strong radiated emission. Influence of ground width to common mode current and emission spectrum were investigated [Oka et al., 1999]. The mechanism of the common mode generation was explained with the unbalance factor of a transmission line called current division factor. Connection of transmission lines having different current division factors generates common-mode excitation source voltage, which is proportional to the difference of the factor [Watanabe, et al., 2000]. High impedance connection of ground planes causes common mode current on a PCB. Dependence on ground structure and its connection to far-field emission was investigated experimentally [Sasabe et al., 2000.11]. Far-field emission was estimated from measured common-mode current and also from FDTD simulation [Sasabe et al., 2000.12, 2001.9], and good agreement with measured field was demonstrated. For the purpose of evaluating immunity of printed circuits, the authors also analyzed the conversion from common-mode to differential-mode on a PCB [Sasabe et al., 2000.4].
Radiation from bent transmission lines was evaluated and dependence of radiation on the curve shape and bend shape was estimated with FDTD method and the method of moments (MoM) [Takahashi, et al., 1999] [Lee, et al., 2000]. Transmission line impedance of a printed line and its near-field were simulated with FDTD method [Kasuga, et al., 2000]. Resonance of a transmission line may cause strong emission, and the resonance frequency is affected by metallic structures close to the line. The effect of a metal plate near a microstrip line to its resonance frequency was simulated with MoM [Sakurai, et al., 2000]. These traditional methods are effective to investigate electromagnetic characteristics of printed circuit structures, though they consume computational resources. As a new approach, the fuzzy inference method was applied to analyze transmission line characteristics [Tayarani and Kami, 2001].
Crosstalk plays a very important role not only in the signal integrity problems but also in the emission problems. Crosstalk from a high-speed signal line to a victim line may cause strong emission even though the signal speed on the victim line is slow. Hence, in design of PCB, we need some guidelines for controlling the crosstalk. For that purpose crosstalk on parallel printed traces was evaluated [Takahashi, et al., 1999], and radiated emission from a PCB was also evaluated for coupling between a low frequency signal trace and a digital signal trace [Oka, et al., 2000]. In some applications such as wireless terminals, coupling between an antenna or RF analog circuits and high-speed digital circuits may cause serious problems in design. The coupling between a monopole antenna and a strip line in a shielding case with slits was investigated numerically with FDTD method and the results were compared with measured ones [Fukasawa, et al., 2000].
For reducing EMI and unintended coupling through lines, ferrite materials are often used. However, the details of their frequency characteristics or loading effects have not been well understood yet. The noise reduction effect of ferrite beads was evaluated with an equivalent circuit [Miyashita, et al., 1999]. More precise matrix-form expression of the load effect of a ferrite core was given [Samir, et al., 2000], in which a practical method for determining the equivalent parameters was given by measuring the scattering parameters. The expression of the load effect of a ferrite was used to analyze crosstalk on parallel two-wire lines [Fujiwara, et al., 2001] and to evaluate far-field radiation and its reduction effect in relation to the position of a ferrite [Maekawa, et al., 2001]. Loading effect of a noise suppression component as a function of loading position was investigated theoretically and experimentally for PCBs exposed to external electromagnetic field [Yamamoto, et al., 2000]. Magnetic film tape was investigated as a counterpart of ferrite cores for noise reduction on cables [Mori and Senda, 2000]. Effect of lossy rubber absorber was analyzed for suppression of coupling between microstrip lines in a metal case of a microwave amplifier module [Saito and Nishikata, 2001]. Shielding effectiveness of an enclosure of an electronic equipment was modeled and analyzed with a spherical shell model [Horagai and Ikeda, 2000].
In the development of electronic systems such as printed circuit boards of digital circuits, to know electric current on a PCB or in components and near-field distribution is helpful to evaluate their electromagnetic characteristics and to improve the design. A method for estimating current distribution on a PCB was proposed, and a mother-board for a workstation was evaluated with small loop magnetic probes [Masuda, et al., 1999]. Position of magnetic field source on a micro processing unit was also estimated with near-field measurement [Doi and Masuda, 2000]. A new method to estimate both current and voltage distributions with one probe was proposed, and the distributions in packaged ICs were evaluated [Kazama, et al., 2000].
In designing high-speed digital circuit boards, it is practically important to control RF noise on power supply interconnections and DC power distribution circuits, such as power and ground planes in multilayer PCBs. The power distribution circuit is usually called as a power bus, which could supply electric power only having low frequency current. However, in practical cases, high-speed operation current should be supplied to a circuit; and since impedance of the power distribution circuit is usually low especially in a multilayer PCB, the high frequency current tends to flow over the power distribution circuit, which may cause radiated emission. To prevent the high-frequency current on the power distribution circuit, decoupling techniques were investigated. The decoupling can be achieved by increasing the RF impedance from a high-speed device to the power bus, or by using decoupling capacitors near the device or on the power bus. For the decoupling, a power wiring technique with long printed traces and another with embedded inductances in a multilayer PCB were demonstrated [Tohya, 1999] [Iwanami, et al., 2000]. Resonance of power bus, which is responsible for strong radiated emission, was investigated theoretically and experimentally, and a technique to control the resonance was presented [Harada, et al., 2000], which utilized decoupling capacitors on a PCB. A technique to optimize the location of the decoupling capacitors was proposed [Kamo, et al., 2001]. To reduce the quality (Q) factor of the power bus resonance, resistive metal films were introduced between power and ground planes in a multilayer PCB, and the resonance characteristics were investigated to optimize the film thickness and its conductivity [Wang, et al., 2001]. For the calculation of the resonance characteristics of the power bus, an improved closed-form expression of the Greens function was adopted to perform fast numerical calculation. The power bus resonance can be excited also by high-speed signal routed through via holes, and improvement of the routing to reduce the power bus noise was investigated experimentally [Tanaka, et al., 2001].
Improvement of packages of active devices was reported to reduce power bus noise. An EMI reduction packaging for LSI was proposed, which achieves the power decoupling with decoupling inductances internally connected to power and ground pins of the package [Fukumoto, et al., 2000]. Ferrite-resin composite material was investigated as package mold of digital ICs to reduce the power bus noise [Akino, et al., 2000]. To simulate the power bus noise effectively, a macro-model of a digital IC and LSI was proposed [Fukumoto, et al., 2001]. The model consists of a linear equivalent internal circuit and internal current source, and is suitable for high-speed EMI simulation.
Regarding immunity of semiconductor devices and PCBs, papers were published on modeling, evaluation and test methods. To investigate immunity to electric coupling between an IC with a metal heat sink and an adjacent noise source, a capacitive coupling model was proposed [Nonaka, et al., 1999]. To achieve fail-safe property of digital systems, a design method of a flip-flop having asymmetric immunity characteristics was proposed [Tsukagoshi, et al., 1999]. Immunity characteristics of MOSFET were investigated and mechanism of its malfunction was presented [Hattori, et al., 1999]. The authors also investigated RF noise immunity of operational amplifiers, both the bipolar type and the MOS type [Hattori, et al 2000]. Noise immunity diagnosis for a PCB was discussed using an equivalent circuit, and the results of experiments were explained with the common-mode impedances [Sasabe, et al., 2000]. A system to detect malfunction area on a PCB was developed and the validity was demonstrated with experiment [Onomae and Nagasawa, 2001]. A novel RF radiated immunity test method was proposed and its basic characteristics were investigated. The method adopts electromagnetic field rotating in low speed; the field is rotated electrically with a newly developed circuit so that its characteristics are easily controlled [Murano and Kami, 1999, 2000.11]. The authors investigated another system for radiated immunity test which utilizes a three-dimensional Helmholtzs coil set [Murano and Kami, 2000.3].

(O. Wada)

E6. EMC related with electrical power engineering

The source element of EMC related with electrical power engineering can be categorized in two types. The one is the induction caused by high voltage and large current characteristics of the power line by its own nature. The other is caused by the apparatuses or faults connected to the power line.
The influences of the electric and magnetic fields to the medical infections of human beings and to the mal-operations of electronics apparatuses are attracted and studied as the former difficulties. The electro magnetic field generated by the over head transmission lines voltages and current and the human body exposure strength are calculated and studied by many researchers and groups leaded by IEE-J (Institute of Electrical Engineering Japan). The studies are mainly discussing about the quantitative values of the electro magnetic field its self and they are different from epidemiology approach which is general research trend in Europe. Their results seem to be given highly political consideration to the utilities.
The induction power source of aerial beacon flash light on the top of transmission tower with using the induction by power line magnetic field was proposed and studied, for it is difficult to obtain adequate electric power source at such location. This work is the enterprising usage of the electro magnetic field generated from over head transmission line that is generally annoying public peoples. The proposed power source uses the induced current on the over head ground wire for the asymmetric arrangement of the three phase power lines and obtains several kW electric powers. The inducted current on the ground wire changes with the current on the power line for it changes with load amount, then the suitable junction span of ground wire to tower body and electrical power storage capacity is discussed to obtain the desired induced current and power quality coping with the periodic load change.
Power Line Carrier (PLC) communication is considered one of the EMC difficulties. The PLC on high voltage transmission line for protective relay information transmission has been studied since a long time ago and the system is almost perfect and left no room for study, then the PLC on distribution line is now being studied. The PLC on distribution line is aiming at internet connection, and the PLC study in Japan is behind Europe. There are two reasons for research subordination. The one is regulation restricted by law. The regulation relating PLC is administrated by different two ministries. The ministry of Economy, Trade and Industry administrates the power line related regulation, and the Ministry of Public management, Home affairs, Posts and telecommunications administrates the communication relating regulation. Though, the deregulation by government has been proceeding recently, but the regulation relating with PLC made little progress for it is extended two ministries. The second reason is the highly prepared optic fiber networks. The Japanese utility companies monopolies the generation, transmission and distribution to the respective territories, and they lay down optic fiber along with the distribution line network. Therefore, the communication requirement with using distribution line is low for they can use optic fiber communication. The subsidiary company of the utility company conducts low power cellular phone system called PHS, and the inspection of the meters is realized by linking the PHS with optical fiber networks. Moreover, the subsidiary company also offers internet provider business with using PHS as the home LAN, and also optical fiber to the home is offered. Therefore, the last one mile difficulty is solved without using PLC. According to those conditions in Japan, it can be expected that the main application of PLC is home LAN system application leaded by household electric appliances with internet access function. The conventional distribution power line inside buildings is not properly twisted and the line impedance is not uniform, then high speed communication has to clear this difficulty and spectrum spread and error correction method are highly expected.
The followings are the EMC problem caused by the harmonics generated by electric apparatus connected to the power line. The dispersed energy system has been growing its number linked to the power system in accordance with the power system deregulation. The isolate operation detection system of the dispersed energy system connected distribution line, which makes the most of the harmonics characteristic in the power system, is proposed. The dispersed energy system can continue its operation even if they are isolated from ac bus by some faults, if the supply and demand is almost balanced. But, this operation continuation gives harmful influences on the power system recovery for the power system protecting relay system does not estimate such operation continuation, then the dispersed energy system must be shut down after such inadequate conditions. The nonlinearity characteristics of the transformer are one of the oldest harmonics difficulties in the power system. The one of the isolate operation detection relay system checks the 3^rd order harmonics on the power line, which increases with the nonlinear affection of the transformer, when the distribution system is isolated from the ac bus. There are other isolation operation detection relay system with using power line characteristics, such as the inter harmonics injection method, reactive power modulation method and frequency bias method are proposed.
The increasing number of electronics devices which use inverters, make the difficulty of harmonics current injection to the power line as the server problem. The Japanese utility companies have been encouraging to establish power factor correction capacitors by the users with giving the incentive of power charge discount. Almost all the power factor correction capacitor does not have circuit breakers which open and closes in accordance with the power factor of the user load and remain connected at all times. Therefore, the amount of power capacitor connected to the power distribution line is highly exceeded and shows leading power factor conditions at night light load, and it makes the undesired phenomena of harmonics magnification at the end of distribution line by the small harmonics injected to the transmission line from some sources. The power line active filter is proposed as the solution of the harmonics suppressions, which is consisted from power electronics inverter. The active filter is specified in two types. The one is series connected type, and the other is parallel connected type. The former one is conventional type active filter, which is suitable when the harmonics source is identified. The last one is the mainstream of active filter study, for it can cope with the harmonics from uncertain sources like the above mentioned harmonics magnification phenomena. Not only harmonics suppressions by active filter, but also harmonics reduction generated from the apparatus is studied. This study is enhanced now because the household electric appliances become to use dc power source by ac/dc converter and the conventional capacitor input type converter generates harmonics and it becomes to dominate the harmonics problems. The main difficulty of this type converter is caused by the pulse shape current containing harmonics and the low power factor. The PWM type converters or dc/dc converter link with PAM operation is studied to cope with these difficulties, which are called PFC and has become to use in the dc power source.
On the other hand, the increasing number of these intelligent type electronics apparatus has made the power quality as the very important issues, such as voltage sag and swells. Though conventional electric apparatuses are not so sensitive, but such new and intelligent apparatuses are very sensitive to the short interruptions or degradation of voltage waveform. The counter measurements to cope with power quality deterioration, the usage of UPS is proposed and studied as the user side local management and DVR is investigated as the aerial management. The configurations and control strategy of the compensation system are enthusiastically discussing now. More over, CRIEPI is proposing demand area power system and several universities unions proposing FRIENDS system as the quality divided power supply system.

(T. Funaki)

References

Natural EM Noise

Ishii, M., K. Michishita, Y. Hongo [1999], "Experimental Study of Lightning-Induced Voltage on an Overhead Wire over Lossy Ground," IEEE Trans. on Electromagnetic Compatibility, Vol.41, No.1, pp.39-45

Michishita, K., M. Ishii, A. Asakawa, S. Yokoyama [1999], "Measurement of Lightning-Induced Voltage on Test Distribution Line Near Tall Structure," Trans. IEE of Japan, Vol.119-B, No.2, pp.238-244 (in Japanese)

Hidayat, S, M. Ishii [1999], "Diurnal Variation of Lightning Characteristics around Java Island," Journal of Geophysical Research,Vol.104, No.D20, pp.24449-24454

Honma, N., P. Wang, M. Ishii [1999], "Numerical Simulation of Propagation Effect on Lightning Field Waveforms," International Workshop on High Voltage Engineering, Naha, SP-99-27/HV-99-27

Suzuki, N., E. Satoh, N. Honma, M. Ishii [1999], "Electromagnetic and Optical Observation of Winter Lightning on the Coast of the Sea of Japan," Proceedings of 5^th International Symposium on Lightning Protection, Sao Paulo, pp.18-22

Ishii, M. [1999], "Recent Researches on Lightning in Japan," Proceedings of 5^th International Symposium on Lightning Protection, Sao Paulo, pp.397-403

Ishii, M., J. Hojo, K. Shimizu, K. Sato, K. Shinjo [1999], "Height of Radiation Sources Associated with Lightning Discharges," Proceedings of 11th International Conference on Atmospheric Electricity, Guntersville, pp.10-13

Ishii, M., Y. Baba [1999], "Characterization of Lightning Current Measured on Tall Structures," Proceedings of the 1999 International Conference on Lightning and Static Electricity, Toulouse, pp.221-224

Hidayat, S., K. T. Sirait, P. M. Pakpahan, M. Ishii, J. Hojo [1999], "Lightning Characteristics on Java Island Observed by Lightning Location Network," 11th International Symposium on High-Voltage Engineering, London, 2.192.S9

Narita, T., T. Yamada, A. Mochizuki, E. Zaima, M. Ishii [2000], "Observation of Current Waveshapes of Lightning Strokes on Transmission Towers," IEEE Trans. on Power Delivery, Vol.15, No.1, pp.429-435

Michishita, K., M. Ishii [2000], "Analysis of Observed Lightning-Induced Voltages by Taking Account of Horizontal E-Field," Trans. IEE of Japan, Vol.120-B, No.10, pp.1304-1308 (in Japanese)

Ishii, M., T. Shindo, N. Honma, Y. Miyake [2000], "Lightning Location Systems in Jaan," Proceedings of 25^th International Conference on Lightning Protection, Rhodes, Vol. A, pp.161-165

Shioda, T., T. Narita, E. Zaima, M. Ishii [2000], "Performance Evaluation of LPATS-T at TEPCO," Proceedings of 25^th International Conference on Lightning Protection, Rhodes, Vol. A, pp.170-175

Michishita, K., M. Ishii, K. Kami [2000], "Induced Voltage on a Test Distribution Line Associated with a Lightning Stroke to a Tall Structure," Proceedings of 25^th International Conference on Lightning Protection, Rhodes, Vol. A, pp.249-254

Pokharel, R.K., M. Ishii Y. Baba [2001], "Numerical Electromagnetic Analysis of Lightning-Induced Voltage over Ground of Finite Conductivity," Proceedings of 12th International Symposium on High Voltage Engineering, Bangalore, Vol. 1, pp.150-153

D. Wang, V. A. Rakov, M. A. Uman, N. Takagi, T. Watanabe, D. E. Crawford, K. J. Rambo, G. H. Schnetzer, R. J. Fisher and Z-I. Kawasaki [1999], Attachment process in rocket-triggered lightning strokes, J. Geophys. Res., 104, D2, 2143-2150 (1999).

S. Yoshihashi, Z-I. Kawasaki, K. Matsuura, N. Takagi, and T. Watanabe [1999], Lightning activity during winter thunderstorm and leader progression in thundercloud, IEE Japan Trans B, 119-B, 3, 375-380 (in Japanese).

S. Yoshihashi, J. Ohnuki, Z-I. Kawasaki, and K. Matsuura [1999], Three-D imaging of lightning channel of multiple-stroke flashe using interferometer, IEE Japan Trans- B, 119-B, 605-613 (in Japanese).

Z-I. Kawasaki, K. Nomura, S. Yoshihash, and K. Matsuura, [1999], Observaton of multiple stroke and multi-point discharge by means of UHF interferometer, IEE Japan Trans- B, 119-B, 614-619 (in Japanese).

Y. shimada, S. Uchida, H. Yasuda, S. Motokoshi, Y. Ishikubo, T. Yamanaka, Z-I. Kawasaki, C. Yamanaka, and M. Adachi [1999], Research on filed experiment of laser triggered lightning, IEE Japan Trans- A, 119-A, 990-996 (in Japanese).

M. Murakami, Z-I. Kawasaki, Y. Ohta, H. Isoda, R. Mardiana, T. Ushio, and K. Matsuura [1999], Comparison between broad band and narrow band interferometer for lightning observation [1999], IEE Japan Trans- B, 119-B, 807-812 (in Japanese).

E. Y. Hamid, Z-I. Kawasaki, M. Mardiana, and K. Matsuura [1999],, TRMM/LIS observations of lightning activity over Indonesia and comparison with ground-base measurement around Java island, J. Atmosp. Electr., Vol. 19, pp 153-164 .

Z-I. Kawasaki [1999], UHF radiation and laser triggered lightning experiment in the field [1999], IEE Japan Trans- B, 119-B, 1001-1006 (1999).

M. Chen, N. Takagi, T. Watanabe, D. Wang, Z-I. Kawasaki and X. Liu[1999], Spatial and temporal properties of optical radiation produced by stepped leaders, J. Geophys. Res., 104, D22, 27573-27584.

Z-I. Kawasaki and S. Yoshihashi [2000], J. Atmosp. Electr., Three dimensional imaging of lightning channel and leader progression velocity, 20,41-52 .

S. F. Hardman, R. L. Dowden, J. B. Brundell, J. L. Bahr, Z-I. Kawasaki and C. J. Roger[2000], Sprite observation in the Northern Territory of Australia, J. Geophys. Res. 105, D4, 4689-4697.
R. Mardiana and Z-I. Kawasaki[2000], Broadband Radio Interferometer Utilizing a Sequential Triggering Technique for Locating Fast-Moving Electromagnetic Sources Emitted from Lightning, IEEE Trans. on Instrumentation and Measurement, Vol. 49, No. 2, 376-381.

S. Yoshihashi, Z-I. Kawasaki, K. Matsuura, H. Isoda, and Y. Sonoi [2000], Three-D imaging of lightning channel and leader progression velocity, IEE Japan Trabns-B, 120-B, 838-843 (in Japanese).

M. Redy and Z-I. Kawasaki [2000], Dependency of VHF broad band lightning source mapping on Fourier spectra , Geophys. Res. Letters. Vol. 27, 2917-2920.

Z-I. Kawasaki, M. Redy, and T. Ushio [2000], Broadband and narrowband RF interferometers for lightning observations, Geophys. Res. Letters. Vol. 27, No. 19 , 3189-3192.

E. Y. Hamid, Z-I. Kawasaki, R. Mardiana [2001], Impact of the 1997-98 El Nino Event of Lightning Activity over Indones, Geophys. Res. Lett. Vol. 28 , No. 1 , 147-150 (2001).

S. Yoshihashi, Z-I. Kawasaki, K. Matsuura, and Y. Sonoi [2001], Three-D observations of positive cloud-to-ground flashes using interferometer, IEE Japan Trans- B, 121-B, 357-363 (2001).

T. Ushio, K. Okamoto, and Z-I. Kawasaki [2001], Gound validation of the lightning imaging sensor (LIS) aboard the tropical rainfall measuring mission(TRMM), IEICE Japan Trans- B Vol.J84-B, 1683-1689 (in Japanese).

T. Ushio, S. J. Heckman, D. J. Boccippio, H. Christian and Z-I. Kawasaki [2001], A survey of thunderstorm flash rates compared to cloud op height using TRMM satellite data, J. Geophys. Res., Vol. 106, 24089-24095 (2001)

Wavelet analysis of voltage disturbances for power quality applications,

Singh, R., B. Singh, V. Bansal, and M. Hayakawa, VLF electromagnetic noise bursts related to major seismic activities observed at Agra, J. Atmos. Electr., Vol. 20, No. 1, pp. 7-20, 2000.

Hayakawa, M., Yu. Kopytenko, N. Smirnova, V. Troyan, and Th. Peterson, Monitoring ULF magnetic disturbances and schemes for recognizing earthquake precursors, Phys. Chem. Earth (A), Vo. 25, No. 3, pp. 263-269, 2000.

Sorokin, V. M., V. M. Chmyrev, and M. Hayakawa, The formation of I onosphere-magnetosphere ducts over the seismic zone, Planet. Space Sci., 48, 175-180, 2000.

Hayakawa, M., O. A. Molchanov, T. Kodama, T. Tanaka, and T. Igarashi, On a possibility to monitor seismic activity using satellites, Adv. Space. Res., Vol. 26, No. 6, pp. 993-996, 2000.

Hayakawa, M. and O. A. Molchanov, Effect of earthquakes on lower ionosphere as found by subionospheric VLF propagation, Adv. Space Res., Vol. 26, No. 8, pp. 1273-1276, 2000.

Hayakawa, M., O. A. Molchanov, T. Kodama, V. V. Afonin, and O. A. Akentieva, Plasma density variations observed on a satellite possibly related to seismicity, Adv. Space Res., Vol. 26, No. 8, pp. 1277-1280, 2000.

Kodama, T., O. A. Molchanov, and M. Hayakawa, NASDA earthquake remote sensing
frontier research -Feasibility of satellite observation of seismoelectromagnetics, Adv. Space Res., Vol. 26, No. 8, pp. 1281-1284, 2000.

Hayakawa, M., T. Itoh, K. Hattori, and K. Yumoto, ULF electromagnetic precursors for
an earthquake at Biak, Indonesia on February 17, 1996, Geophys. Res. Let., Vol.
27, No. 10, pp. 1531-1534, 2000.

Hayakawa, M., Electromagnetic phenomena associated with earthquakes, Bulletin of the Univ. of Electro-Comm., 13-1, pp. 1-6, 2000.

Hobara, Y., H. Yamaguchi, T. Watanabe, Y. Akinaga, H. C. Koons, J. L. Roeder, and M. Hayakawa, Wide-band ULF/ELF magnetic field measurement in Seikoshi, Izu Japan and some results from preliminary data analysis in relation with seismic activity, J. Atmos. Electr., Vol. 20, No. 2, pp. 111-121, 2000.

Ohta, K., K. Makita, and M. Hayakawa, On the association of anomalies in subionospheric VLF propagation at Kasugai with earthquakes in the Tokai area, Japan, J. Atmos. Electr., Vol. 20, No. 2, pp. 85-90, 2000.

Gotoh, K. and M. Hayakawa, A proposal on the applicationof blind separation for identification of seismo-ULF emissions under the noisy environment, Inst. Electr. Info. Comm. Engineers, J83A, 1477-1485, 2000 (in Japanese)

Toshiyasu Nagao, Yoshiaki Orihara, Tohru Yamaguchi, Ichiro Takahashi, Katsumi Hattori, Yoichi Noda, Keizo Sayanagi and Seiya Uyeda, Co-seismic geoelectric potential changes observed in Japan, Geophysical Research Letters, Vol. 27, No. 10, 1535-1538, 2000.

Seiya Uyeda, Toshiyasu Nagao, Yoshiaki Orihara, Tohru Yamaguchi and Ichiro Takahashi, Geoelectric potential changes: Possible precursors to earthquakes in Japan, Proceedings of the National Academy of Sciences of the United States of America, Vol. 97, No. 9, 4561-4566, 2000.

Tohru Yamaguchi, Yoichi Noda, Ichiro Takahashi, Yoshiaki Orihara, Katsumi Hattori, Koki Kawabata, Toshiyasu Nagao and Seiya Uyeda, A regionally observed simultaneous pre-seismic geoelectric potential change in Nagano Prefecture, Japan, Bulletin of Institute of Oceanic Research and Development, Tokai University, 21, 11-22, 2000 (in Japanese with English abstract

Fukumoto, Y., M. Hayakawa, and P. F. Biagi, Seismic effect on the propagation of subionospheric LF radio waves in Italy, J. Atmos. Electr., 21, 1, 1-7, 2001.

Molchanov, O. A. and M. Hayakawa, VLF monitoring of atmosphere-ionosphere

boundary as a tool to study planetary waves evolution and seismic influence, Phys. Chem. Earth, Part C, 26, No.6, 453-458, 2001.

Kopytenko, Yu., V. Ismagilov, M. Hayakawa, N. Smirnova, V. Troyan, and T. Prterson, Investigation of the ULF electromagnetic phenomena relaed to earthquakes: contemporary achevements and the perspectives, ANNALI DI GEOFISICA, Vol.44, N.2, pp.325-334, 2001.

Hayakawa, M., Electromagnetic phenomena associated with earthquakes: Review, Trans. Ins. Electr. Engrs. of Japan, Vol.121-A, No.10, p.893-898, 2001.

Hattori, K., Earthquake-related electromagnetic phenomena originated in Lithosphere, J.,Inst. Electrostatics Japan, 25, 238-245, 2001. (in Japanese)

Fujinawa, Y., Studies on VLF band electric field variations related with earthquakes and volcanic eruption, J. Inst. Electrostatics Japan, 25, 246-255, 2001. (in Japanese)

Hayakawa, M., Seismo-Ionospheric Electromagnetic Phenomena, J. Inst. Electrostatics Japan, 25, 256-262, 2001. (in Japanese)

Biagi, P. F., R. Piccolo, A. Ermini, S. Martellucci, C. Bellecci, M. Hayakawa, V. Capozzi, and S. P. Kingsley, Possible earthquake precursors revealed by LF radio signals, Natural Hazards

Earth Sys. Sci., 1, 99-104, 2001.

Molchanov, O. A., M. Hayakawa, and K. Miyaki, VLF/LF sounding of the lower ionosphere to study the role of atmospheric oscillations in the lithosphere-ionosphere coupling, Adv. Polar Upper Atmos. Res., 15,146-158, 2001.

Ismaguilov, V. S., Yu. A. Kopytenko, K. Hattori, P. M. Voronov, O. A. Molchanov, and M. Hayakawa, ULF magnetic emission connected with under sea bottom earthquakes, Natural Hazards Earth Sys. Sci., 1, 23-31, 2001.

Akinaga, Y., M. Hayakawa, J. Y. Liu, K. Yumoto, and K. Hattori, A precursory ULF signature for the Chi-Chi earthquake in Taiwan, Natural Hazards Earth Sys. Sci., 1, 33-36, 2001.
Molchanov, O., A. Kulchitsky, and M. Hayakawa, Inductive seismo-electromagnetic effct in relation to seismogenic ULF emission, Natural Hazards Earth Sys. Sci., 1, 61-67, 2001.
Ohta, K., K. Umeda, N. Watanabe, and M. Hayakawa ULF/ELF emissions observed in Japan, possibly associated with the Chi-Chi earthquake in Taiwan., Natural Hazards Earth Sys. Sci., 1, 37-42, 2001.

Smirnova, N., M. Hayakawa, K. Gotoh, D. Volobuev, Scaling chracteristics of ULF geomagnetic field at the Guam seismoactive area and their dynamics in relation to the earthquake., Natural Hazards Earth Sys. Sci., 1, 1-8, 2001

V. Pilipenko, S. Shalimov, S. Uyeda, M.J.A., and H. Tanaka, Possible mechanism of the over-horizon reception of FM radio waves during earthquake preparation period, Proceedings of the Japan Academy, Vol. 77, Ser. B, No. 7, 125-130, 2001.

K. Sakai, T. Takano, and S. Shimakura, Observation system for anomalous propagation of FM radio broadcasting wave related to earthquakes and its preliminary result, J. Atmospheric Electricity, Vol. 21, No. 2, 71-78, 2001

Gotoh, Kaoru, Yoshikazu Akinaga, Masahi Hayakawa, and Katumi Hattori, Principal component analysis of ULF geomagnetic data for Izu islands earthquakes in July 2000, J. Atmos. Electr., Vol. 22, No. 1., pp. 1-12, 2002.

T. Nagao, Y. Enomoto, Y. Fujinawa, M. Hata, M. Hayakawa, Q. Huang, J. Izutsu, Y. Kushida, K. Maeda, K. Oike, S. Uyeda, and Takeo Yoshino, Electromagnetic anomalies associated with 1995 KOBE earthquake, Journal of Geodynamics, Vol. 33, No. 4-5, 349-359, 2002.
Y. Orihara, Y. Noda, T. Nagao, and S. Uyeda, A possible case of SES selectivity at Kozu-shima Island, Japan, Journal of Geodynamics, Vol. 33, No. 4-5, 361-368, 2002.

Saya Kondo, Seiya Uyeda, and Toshiyasu Nagao, The selectivity of the Ioannina VAN station, Journal of Geodynamics, Vol. 33, No. 4-5, 369-400, 2002

T. Takano, A, Yamada, K. Sakai, H. Higasa, and S. Shimakura, Enhancements of electromagnetic broadband noise in 50MHz band which possibly associate with earthquakes, J. Atmospheric Electricity, Vol. 22, No. 1, 23-34, 2002.

V. Gladyshev, L. Baransky, A. Schekotov, E. Fedorov, O. Pokhotelov, S. Andreevsky, A. Rozhnoi, Y. Khabazin, G. Belyaev, A. Gorbatikov, E. Gordeev, V. Chebrov, V. Sinitsin, A. Lutikov, S. Yunga, G. Kosarev, V. Surukov, O. Molchanov, M. Hayakawa, and S. Uyeda, Some preliminary results of seismo-electromagnetic research at Complex Geophysical Observatory, Kamchatka, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 421-432, Terra Scientific Publishing Company, Tokyo, 2002.

A. V. Gorbatikov, O. A. Molchanov, M. Hayakawa, S. Uyeda, K. Hattori, T. Nagao, A. V. Nikolaev, and P. Maltsev, Acoustic emission possibly related to earthquakes observed at Matsushiro, Japan and its implications, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 1-10, Terra Scientific Publishing Company, Tokyo, 2002.

K. Hattori, Y. Akinaga, M. Hayakawa, K. Yumoto, T. Nagao, and S. Uyeda, ULF magnetic anomaly preceding the 1997 Kagoshima earthquakes, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 19-28, Terra Scientific Publishing Company, Tokyo, 2002.

K. Sakai, T. Ito, T. Takano, and S. Shimakura, The basic research of anomalous propagation of FM radio broadcasting wave related to earthquakes, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 259-262, Terra Scientific Publishing Company, Tokyo, 2002.

S. Uyeda, T. Nagao, K. Hattori, Y. Noda, M. Hayakawa, K. Miyaki, O. Molchanov, V. Gladychev, L. Baransky, A. Schekotov, G. Belyaev, E. Fedorov, O. Pokhotelov, S. Andreevsky, A. Rozhnoi, Y. Khabazin, A. Gorbatikov, E. Gordeev, V. Chebrov, and A. Lutikov, S. Y., Russian-Japanese complex geophysical observatory in Kamchatka region for monitoring of phenomena connected with seismic activity, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 413-420, Terra Scientific Publishing Company, Tokyo, 2002.

A. Yamada, K. Sakai, Y. Yaji, T. Takano, and S. Shimakura, Observation of natural noise in VHF band which relates to earthquakes, in Seismo Electromagnetics (Lithosphere-Atmosphere-Ionosphere Coupling), edited by M. Hayakawa and O. A. Molchanov, pp. 255-257, Terra Scientific Publishing Company, Tokyo, 2002.

Man made EM Noise

Akino, T., Y. Ono, S. Shinohara and R. Sato [2000], Reduction Method of Voltage Fluctuation of DC Power Supply in Digital IC, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 622-625.

Doi, T. and N. Masuda [2000], Leakage Magnetic Field Source Searching of Micro Processing Unit on Printed Circuit Board, Trans. IEE of Japan, vol. 120-A, no. 10, pp. 871-877.
Fujiwara, O., T. Maekawa and A. Z. Samir [2001], An Analysis of Load Effect due to Ferrite Core Attachment to Parallel Two-Wire Lines above a Ground Plane, Trans. IEICE B, vol. J84-B, no. 3, pp. 562-569.

Fukasawa T., C. Miyazaki, S. Makino and S. Urasaki [2000], Calculation of Coupling between a Monopole Antenna and a Strip Line in a Shield Case for a Portable Telephone, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 505-510.

Fukumoto, Y., T. Ogura, O. Wada and R. Koga [2000], Suppression of High Frequency Current on Power Plane of PCB by EMI Reduction LSI Package, Journal of Japan Institute of Electronics Packaging, vol. 3 , no. 6 , pp. 515-522.

Fukumoto, Y., Y. Takahata, O. Wada, Y. Toyota, T. Miyashita and R. Koga [2001], Power Current Model of LSI/IC Containing Equivalent Internal Impedance for EMI Analysis of Digital Circuits, IEICE Trans. Commun., vol. E84-B, no. 11, pp. 3041-3049.
Harada, T., H. Sasaki and Y. Kami [2000], Controlling Power-Distribution-Plane Resonance in Multilayer Printed Circuit Boards, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 577-585.

Hattori, Y., H. Tadano and H. Nagase [1999], A Study od DC Operating Point Shifts in MOSFETs with Large RF Signals, Trans. IEICE B, vol. J82-B, no. 12, pp. 2375-2383.

Hattori, Y., H. Tadano, H. Nagase and K. Itoigawa [2000], A Study on RF Noise Immunity of Operational Amplifiers, Trans. IEICE B, vol. J83-B, no. 7, pp. 1034-1042.

Horagai, N. and T. Ikeda [2000], Shielding Effectiveness of a Shell Model, Trans. IEICE B, vol. J83-B, no. 6, pp.881-884.

Iwanami, M., S. Hoshino, T. Kuriyama and H. Tohya [2000], Electrical Characteristics of Printed Circuit Boards Constructed with Two Ground Planes and a Coil-Shaped Conductor, Trans. IEE of Japan, vol. 120-A, no. 10, pp. 885-893.

Kamo, A., T. Watanabe and H. Asai [2001], A New Methodology for Optimal Placement of Decoupling Capacitors on Printed Circuit Board, IEICE Trans. Fundamentals, vol. E84-A, no. 12, pp. 3177-3181.

Kasuga, T., M. Tanaka and H. Inoue [2000], FDTD Simulation and Experimental Study on Line Impedance and Magnetic Near Field Noise for a Simple Printed Line Model, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 561-568.

Kazama, S., S. Shinohara and R. Sato [2000], Estimation of Current and Voltage Distributions by Scanning Coupling Probe, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 460-466.
Lee, S., M. Hayakawa and N. Ishibashi [2001], Radiation from Bent Transmission Lines, IEICE Trans. Commun., vol. E84-B, no. 9, pp. 2604-2609.

Maekawa, T. and O. Fujiwara [2001], Calculation of Electric Far-Field Radiation from Transmission Line Attached to a Ferrite Core above a Ground Plane, Trans. IEICE B, vol. J85-B, no. 12, pp. 2374-2382.

Masuda, N., Y. Midorikawa, Y. Saito and H. Tohya [1999], A Study of Current Distributions on the Printed Circuit Boards, Trans. IEE of Japan, vol. 119-A, no. 7, pp. 997-1004.
Miyashita, T., S. Nitta and A. Mutoh [1999], Prediction of Noise Reduction Effect of Ferrite Beads on EMI Emitted from a Printed Circuit Board, Trans. IEICE B, vol. J82-B, no. 2, pp. 322-329.

Mori, T. and M. Senda [2000], EMI Noise Reduction Tape Containing Magnetic-Alloy Film, IEICE Trans. Commun., , vol. E83-B, no. 3, pp. 600-607.
Murano, K. and Y. Kami [1999], A Generation Method of Electromagnetic Fields Rotating at a Low Speed for the Immunity Test, IEICE Trans. Commun., , vol. E82-B, no. 3, pp. 567-569.
Murano, K. and Y. Kami [2000], Low Frequency Radiated Immunity Test Using Three-Dimensional Helmholtz-Coil Set, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 467-473.
Murano, K. and Y. Kami [2000], An RF Radiated Immunity Test Method Using an EM Field of Low Speed Rotation and its Basic Characteristics, Trans. IEE of Japan, vol. 120-A, no. 11, pp. 1044-1050.

Nonaka, J., S. Nitta and A. Mutoh [1999], The Influence of Plate Type Heat Synk on the Interference between Adjacent Printed Circuit Boards; The Case of Capacitive Coupling, Trans. IEICE B, vol. J82-B, no. 2, pp. 314-321.

Oka, N., C. Miyazaki, T. Uchida, S. Nitta [1999], Influence of Ground Plane Width on Reduction of Radiated Emission from Printed Circuit Boards, Trans. IEICE B, vol. J82-B, no. 8, pp.1586-1595.

Oka, N., C. Miyazaki and S. Nitta [2000], Evaluation of Emission from a PCB by Using Crosstalk between a Low Frequency Signal Trace and a Digital Signal Trace, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 586-592.

Onomae, H. and Y. Nagasawa [2001], A System Detecting Malfunction Areas with ESD Simulator for PCBs, Trans. IEICE B, vol. J84-B, no. 8, pp. 1514-1522.

Saito, A. and A. Nishikata [2001], Analysis for the Suppression of Coupling between Two Microstrip Lines in Microwave Amplifier Module by Lossy Magnetic Material Loading, Trans. IEICE B, vol. J84-B, no. 10, pp. 1834-1840.

Sakurai, A., H. Tominaga and T. Asano [2000], Resonance Frequency Variation with a Nearby Floated Metal Plate, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 555-560.

Samir, A. Z. and O. Fujiwara [1999], Measurement and Verification of Complex Permittivity of Ferrite Material by S-Parameter Techniques, Trans. IEE of Japan, vol. 119-C, no. 1, pp. 9-14.

Samir, A. Z., J. W. Wang and O. Fujiwara [2000], A Practical Approach for Estimation of Load Effect Produced by Ferrite Core Attached to Wire above a Ground Plane, Trans. IEE of Japan, vol. 120-C, no. 1, pp. 8-13.

Sasabe, K., K. Yosyida and O. Fujiwara [2000], Experimental Investigation of Noise Immunity Diagnosis for Battery Drived Circuit by Bulk Current Injection Test, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 618-621.

Sasabe, K., K. Yoshida and O. Fujiwara [2000], An Analysis of the Conversion from Common to Differential-mode Noise on the Balanced Line, Trans. IEE of Japan, vol. 120-C, no. 4, pp. 583-589.

Sasabe, K., K. Yoshida and O. Fujiwara [2000], An Effect of the Ground Plane on the Radiated Emission for Motherboard PCB, Trans. IEICE C1, vol. J83-B, no. 11, pp. 1642-1644.

Sasabe, K., K. Yoshida and O. Fujiwara [2000], A Prediction of Electric Far-field Strength from Printed Circuit Boards by Measuring the Common-Mode Current, Trans. IEE of Japan, vol. 120-C, no. 12, pp. 1920-1926.

Sasabe, K., J. Wang and O. Fujiwara [2001], An Estimation of Electric Far-Field Strength Radiated from Printed Circuit Boards by A FDTD Calculation of Common-mode Current on the Trace Pattern, Trans. IEE of Japan, vol. 121-A, no. 9, pp. 823-827.

Takahashi, M., M. Takahashi and M. Abe [1999], Radiation Electromagnetic Waves Suppressed by the Curve Shape of Microstripline, Trans. IEICE B, vol. J82-C1, no.9, pp. 561-569.

Takahashi, T., T. Sakusabe, N. Schibuya and H. Maeda [1999], Analysis of Cross Talk Noise on Parallel Traces with Non Equivalent Length, Trans. IEICE B, vol. J82-B, no. 4, pp. 653-660.

Tanaka, M., Y. Ding, J. L. Drewniak and H. Inoue [2001], Diagnostic Procedure for EMI Resulting from High-Speed Routing between Power and Ground Planes, IEICE Trans. Commun., vol. E84-B, no. 7, pp. 1970-1972.

Tayarani, M and Y. Kami [2000], Qualitative analysis in engineering electromagnetics; An application to general transmission lines, IEICE Trans. Electronics, vol. E84-C, no. 3, pp. 364-375.

Tohya, H. [1999], , Technologies Doing Much for Solving the EMC Problem in the High Performance Digital PCBs and Equipment, IEICE Trans. Fundamentals, vol. E82-A, no. 3, pp. 450-456.

Tsukagoshi, T., S. Nitta and A. Mutoh [1999], The Design Method of Flip-Flop with Asymmetric Noise Immunity Characteristics, Trans. IEICE B, vol. J82-B, no. 6, pp. 1269-1277.

Wang, Z. L., O. Wada, Y. Toyota and R. Koga [2001], Reduction of Q-factor of resonance in power/ground planes of multilayer PCBs by using resistive metal films, Trans. IEE of Japan, vol. 121-A, no. 10, pp. 928-932.

Watanabe, T., O. Wada, T. Miyashita and R. Koga [2000], Common-Mode-Current Generation Caused by Difference of Unbalance of Transmission Lines on a Printed Circuit Board with Narrow Ground Pattern, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 593-599.

Yamamoto, H., S. Shinohara and R. Sato [2000], The Effect of Impedance Loading Position on Induced Voltage Suppression, IEICE Trans. Commun., vol. E83-B, no. 3, pp. 569-576.
H.Echigo, T.Hachiya, R.Sato: "Radio noise measurement near the vehicle traffics", Proc. of International Symposium on EMC/Tokyo, 20P506, p.774-777 (May,1999)

M.Tanigaki, H.Echigo, M.Kamiyama:"Simulation of cutoff frequency in TEM cell by boundary scaling functions", Proc. of 2001 IEEE AP-S/URSI Symposium/Boston,Vol.1,29,pp.596-599 (July, 2001)

H.Echigo, R.Sato : "Calculation of transient response on circuits constructed with resistors and equi-length transmission lines", Proc. of PIERS2001/Osaka, p.379 (July, 2001)

Y.Itoh,K.Sato,H.Echigo : "Time domain measurements of EM field pattern to animate the radio wave propagation", Proc. of AP-RASC'01/Tokyo, p.61(August, 2001)

H.Echigo, R.Sato : "Representing function for extreme value distribution to describe the low time rate portion of radio noise", Proc. of AP-RASC'01/Tokyo, p.61 (August, 2001)

H.Echigo, R.Sato : "The mathematical representation for the variation of levels with small occurrence rate in radio noise", Proc. of 2001 IEEE International Symposium on EMC/Montreal, pp.870-875 (August, 2001)

T. Harada, H. Sasaki, and Y. Kami Controlling power distribution plane resonance in multilayer printed circuit boards, IEICE Trans. Commun., vol.E-83, no.3, pp.577-585, March 2000.

K. Murano and Y. Kami Low frequency radiated immunity test using three-dimensional Helmholtz-coil set, IEICE Trans. Commun. Vol.E83-B, no.3, pp.467-473, March 2000.
K. Murano and Y. Kami, Basic characteristics of 3-dimensional Helmholtz coils for radiated immunity test,Trans. IEE of Japan, 119-A,12,pp.1409-1415, Dec., 1999.
K. Murano, M. Tayarani, Y. Kami, Wide-band phase splitter using DBM,IEICE Trans. Commun. , J83-B, 1, pp.131-133, 2000-1.

M. Tayarani, and Y. Kami Fuzzy inference in engineering electromagnetics: An application to conventional and angled monopole-antenna, IEICE Trans. Electron., vol.E83-C, no.1, pp.85-97, Jan. 2000.

T. Harada, H. Sasaki, and Y. Kami Investigation on power distribution plane resonance in multilayer printed circuit boards using a transmission-line model, Proc. of 1999 Intn. Symp. Electromag. Compat., pp.21-24, May 1999.

K. Murano, A.Shiokawa and Y. Kami Three directional helmholtz coils for a low frequency-magnetic-field immunity test, Proc. of 1999 Intn. Symp. Electromag. Compat., pp.79-81, May 1999.

M. Tayarani, and Y. Kami A new modeling approach in engineering electromagnetics using fuzzy inference, Proc. of 1999 Intn. Symp. Electromag. Compat., pp.106-109, May 1999.
W.Liu and Y.Kami Vertical riser effects of a finite-length transmission line, Proc. of 1999 Intn. Symp. Electromag. Compat., pp.642-645, May 1999.

W.Liu and Y.Kami Discontinuity effects for a cascaded transmission-line system consisting of two line sections of different height, Proc. of 1999 IEEE Intn. Symp. Electromag. Compat., pp.526-530, August 1999.

M. Tayarani, and Y. Kami "A Fuzzy Model for Input Impedance of a General Monopole Antenna", 1999 IEEE International Conference on Systems, Manand Cybernetics, October 12-15, 1999, Tokyo, Japan, pp.VI-173 to 178

K. Murano,Y. Kami, An RF radiated immunity test method using an EM field of low speed rotation and its basic characteristics, Trans. IEE of Japan, Vol. 120-A,No. 11,pp. 1044-1050, Nov. 2000.

M. Tayarani, and Y. Kami Qualitative analysis in engineering electromagnetics; An application to general transmission lines, IEICE Transactions on Electronics, Vol. E84-C, No. 3, pp. 364-375, March 2001.

M. Tayarani, and Y. Kami Fuzzy Modeling of Nonuniform Transmission Lines,Proc. of IEEE Intern. Symp. Antennas Propagat, pp.737-740, Aug. 2000.M. Tayarani, and Y. Kami Toward Qualitative Study of Transmission Lines Using Fuzzy Inference,Proc. of 4th European Symp. Electromag. Compat., pp.233-238, Sept. 2000.

M. Tayarani, and Y. Kami A qualitative analysis approach for externally excited transmission lines, Intern. Zurich Symp. and Tech. Exhibition on EMC, Zurich, Switzerland, pp. 589-594, Feb. 2001.

M. Tayarani, and Y. Kami: A new approach to analysis and modeling of externally excited transmission lines using fuzzy inference, Trans. IEE of Japan, Vol.121-A, No.6, pp.547-553, June 2001.

H. Hirayama, T. Yakabe and Y. Kami: An imaging system for EM emitting sources using a six-port interferometer; IEICE Trans. Electron., Vol.E84-C, No.12, pp.1885-1891, Dec., 2001.
F. Xiao, and W. Liu, and Y. Kami: Analysis of crosstalk between finite-length microstrip lines: FDTD approach and ciruit-concept modeling, IEEE Trans. Electromagn. Compat., Vol.43, No.4, pp.573-578, Nov. 2001.

F. Xiao, and Y. Kami: Design of a log-periodic dipole array for pulsed electromagnetic compatibility testing using a genetic algorithm, Progress In Electromagnetics Research Symp. Proceedings, p.378, July 2001.

M. Tayarani, and Y. Kami: A novel approach analysis and modeling of electromagnetic problems using fuzzy inference system, Progress In Electromagnetics Research Symp. Proceedings, p.395, July 2001.

K. Murano and Y. Kami: A study of three-dimensional RF radiated immunity test method using EM field of low speed rotation, Progress In Electromagnetics Research Symp. Proceedings, p.594, July 2001.

Y. Kami: Susceptibility and immunity characteristics of circuits on a PCB, 2001 Asia-Pacific Radio Science Conference Record, E8-3, Aug. 2001.

F. Xiao, and Y. Kami: Trnasient response of nonuniform and uniform transmission lines excited by external field, 2001 IEEE EMC Intn. Symp. Record, pp.210-215, Aug.,2001.

H. Hirayama, T. Yakabe and Y. Kami :An imaging system for EM emitting sources using a 6-port correlator, 2001 IEEE EMC Intn. Symp. Record, pp.374-377, Aug.,2001.

K. Murano and Y. Kami :A study of three-dimensional immunity characteristics of an EUT using low-speed rotation fields, 2001 IEEE EMC Intn. Symp. Record, pp.527-530, Aug.,2001.

W. Liu, S. Nishikado and Y. Kami :Electromagnetic fields and transmission characteristics of a filter composed of transmission lines, 2001 IEEE EMC Intn. Symp. Record, pp.1111-1116, Aug.,2001.

T. Sanpei, K. Murano, K. Nakada, and Y. Kami: An immunity mapping method by using EM field with a slowly rotating polarization, Korea-Japan AP/EMC/EMT Joint Conference Proceedings , pp. 192-195, Sep.,2001.