bluuebunny/crossref_metadata_2025_split huggingface dataset:
IP‐HDTV multicast distribution system architecture with nonstop service availability
Authors: Hasegawa Teruyuki , Kamimura Kazuhiro , Hoshino Haruo , Ano Shigehiro , Hasegawa Toru 
Published: June 2007

AbstractThis paper proposes a new system architecture which achieves stable HDTV distribution service using ISP multicast networks. With the recent spread of broadband access networks including FFTH, the distribution of broadcasting contents using IP multicast is becoming indispensable in the ISP service menu. The important issues in the development of such a content distribution service are to provide high service availability and to construct a highly flexible distribution system that can handle various distribution formats. The authors have proposed a nonstop IP multicast technique without modification of router implementation intended for the ISP network, and also a packet transmission control procedure which works independently of the distribution format. A prototype was implemented and a video distribution experiment is performed on an IP multicast network corresponding to digital HDTV broadcasting by satellite. It is shown that nonstop service can be provided using the prototype system, compensating the loss of approximately 27,500 packets, accompanied by detection and recovering of network failure at the router. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 73–85, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20346
Location estimation using received signal power and maximum likelihood estimation in wireless sensor networks
Authors: Takashima Masahiro , Zhao Dapeng , Yanagihara Kentaro , Fukui Kiyoshi , Fukunaga Shigeru , Hara Shinsuke , Kitayama Ken‐Ichi 
Published: June 2007

AbstractThis paper considers the sensor network based on IEEE 802.15.4, and proposes a method in which a probabilistic model of wireless propagation characteristics in a real environment is constructed, and the node position is estimated by maximum‐likelihood estimation using the model. The performance of the proposed method is evaluated by simulation and position estimation experiments based on the probabilistic model obtained from the actual indoor measurement. It is shown that the proposed method is useful for indoor personnel location management. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 62–72, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20359
Control of heating pattern for interstitial microwave hyperthermia by a coaxial‐dipole antenna—aiming at treatment of brain tumor
Authors: Kikuchi Satoru , Saito Kazuyuki , Takahashi Masaharu , Ito Koichi 
Published: June 2007

AbstractInterstitial microwave hyperthermia is one of the modalities for cancer treatment that insert a thin microwave antenna into the affected part to selectively heat only the tumor. The authors are investigating this technique with an aim of clinical applications of this medical treatment for brain tumors. In the clinical treatment of brain tumors, it is more critical that “only the tumor parts be heated” than for the treatment of other tissues. Therefore, an antenna that can generate a localized heating pattern on the tumor is required. Although the heating pattern can be controlled here in the longitudinal direction of the antenna by using multiple antennas to form an array applicator, control of the heating pattern in the axial direction is relatively difficult. In this paper, to enable the heating pattern to be controlled in the axial direction, the authors introduced a coaxial‐dipole antenna and improved its structure. In addition, they assumed that it was actually applied in the medical treatment of brain tumors and used a numerical calculation model that included a tumor created from MR images to verify the effectiveness of the improved coaxial‐dipole antenna according to numerical calculations. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 31–38, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20390
A planar dipole antenna with wideband characteristics for UWB and wireless LAN
Authors: Horita Atsushi , Iwasaki Hisao 
Published: June 2007

AbstractIn recent years, attention has focused on UWB (Ultra Wideband), which is suitable for high‐speed, large‐capacity near‐distance wireless communication systems. Since UWB uses the 3.1‐ to 10.6‐GHz bands, research and development into antennas capable of obtaining wideband characteristics has become active. Research has also accelerated on antennas that can be shared with wireless LAN and other wireless communication systems. In this paper, we propose a wideband characteristics method that uses trapezoidal conductors for planar dipole antennas that satisfy the ultrawide bandwidths required for UWB, and for planar asymmetric dipole antennas that can be used for both IEEE802.11b/g, a wireless LAN in the 2.4‐GHz band, and UWB. We performed analysis and measurement of impedance characteristics, and of directionality in each frequency band, and confirmed that the analysis results and measurement results virtually match. We also performed measurement to study group delay characteristics. We used the proposed method to achieve an antenna that is effective for both UWB and the 2.4‐GHz‐band wireless LAN, and showed the validity of the wideband characteristics method. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 22–30, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20395
MMSE/EGC adaptive selection for nonuniformly aligned adaptive array antenna
Authors: Takahashi Masayuki , Fujii Takeo , Kamiya Yukihiro , Suzuki Yasuo 
Published: June 2007

AbstractWhen an adaptive array antenna is used in cellular and other mobile communication base stations for the purpose of improving SINR, the array antenna itself sometimes falls into a fading valley, resulting in failure to obtain an adequate improvement effect. While this problem can be solved by increasing the aperture length of the array antenna, simply increasing the aperture length alone increases the number of antenna elements, so that a large‐scale adaptive array antenna becomes required, leading to the problem of failure of the weighting to track changes in the environment during fast fading. In this paper, we try to solve the first issue by making the element spacing nonuniformly aligned, reducing the number of elements. For the second issue, the weighting is divided into two layers, resolving the problem through both use of MMSE to eliminate interference and use of EGC for diversity combining. In a slow fading environment, however, favorable characteristics can be obtained when the entire weighting is controlled by MMSE. In this paper, we estimate the fading speed by the amount of envelope fluctuation in the desired signal after elimination of interference by the initial layer MMSE, and propose during slow fading the use of MMSE batch control, and during fast fading a control that incorporates both MMSE and EGC diversity combining. Finally, we use a computer simulation to evaluate the validity. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(12): 13–21, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20397
A proposal of traffic control mechanism in PON based access system
Authors: Iwata Toshiyuki , Nakanishi Yasuhiko , Maeda Yoichi 
Published: June 2007

AbstractWe propose a bandwidth control method to increase or decrease the entire assigned upstream bandwidth by monitoring the queue length in order to prevent a drop in the throughput and an increase in the delay time when congestion is produced by the traffic generated by multiple users in a passive optical network (PON)‐type optical access system for economically providing wideband multimedia services. The ability of the proposed method to avoid congestion, improve the Transmission Control Protocol (TCP) throughput, reduce the delays, and assure fairness between the TCP and User Datagram Protocol (UDP) traffic is demonstrated in computer simulations by applying the proposed method to the Broadband‐PON (B‐PON) system which complies with the ITU‐T standard. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(7): 41– 55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20374
Disaggregation and surface modification of nano‐size diamond by ultrasound exposure: Relationships among acoustic intensity, disaggregation, and surface modification
Authors: Uchida Takeyoshi , Hamano Akiko , Kawashima Norimichi , Takeuchi Shinichi 
Published: June 2007

AbstractWe used ultrasound exposure to perform disaggregation and surface modification of aggregated nano‐diamond particles. We formed a standing‐wave sound field using a Langevin transducer to drive a stainless‐steel vibrating disk installed at the bottom of a water tank, and generated efficient acoustic cavitation. With 20 minutes of ultrasonic exposure, we were able to reduce aggregated nano‐diamond particles with average particle diameters of 5µm to average particle diameters of 100 nm or less. We also confirmed that we had improved the zeta potential, an index of surface modification, by a factor of more than two. Furthermore, we used a hydrophone to measure the sound field inside the water tank, and calculated the average acoustic intensity at 800W/m2or more to demonstrate that the nano‐diamond surfaces had been modified. We confirmed that the zeta potential and average particle diameter of the nano‐diamonds could be maintained for at least 150 days after ultrasound exposure. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(12): 10– 18, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20268
Two computational algorithms for deriving phase equations: Equivalence and some cautions
Authors: Ohta Daisuke , Tanaka Hisa‐Aki , Maino Yusuke 
Published: June 2007

AbstractWhen synchronization phenomena are analyzed, the phase equations are known to often provide useful qualitative and quantitative information [1]. The target of this paper is to examine through comparisons of the derivation algorithm of the phase equations a realistic system including the case where the equations are not necessarily given explicitly. In other words, the equivalence of two different conventional algorithms [1, 4] is shown, and the advantages and cautions when specific phenomena use both in an example are each explained. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(12): 1– 9, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20284
A data‐driven processor for alleviating bottlenecks of sequential programs and maintaining multiprocessing capability
Authors: Kurebayashi Ryosuke , Ito Shinya , Takahashi Toru , Tomiyasu Hiroshi , Nishikawa Hiroaki 
Published: June 2007

AbstractExisting data‐driven processors offer the advantages of being able to naturally resolve the problems inherent in a wide variety of granularities of parallelism, and of being able to multiprocess without overhead. However, because an instruction is not issued until the instruction that generates the source operand finishes executing, a delay equal to the number of stages in the pipeline occurs before an instruction that has a data‐dependency relationship can be executed. As a result, portions of sequential processing in a program become a bottleneck. The authors are therefore in the process of developing an LSI processor that is able to retain the advantages of conventional data‐driven processors while being able to efficiently execute blocks of sequential processing. This paper presents and evaluates the performance of the proposed execution model and pipeline structure of this processor. This processor uses the same pipeline to perform instruction level multiprocessing of data‐driven programs that issue instructions based on the data‐dependency relationships and control‐driven programs that issue instructions sequentially based on a program counter. The effectiveness of parallel processing by data‐driven programs, improvements in the efficiency of sequential processing by introducing control‐driven programs, and the ability to evenly share the pipeline when data‐driven and control‐driven programs are multiprocessing are evaluated. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(12): 36–49, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20358
Uncalibrated 3D visual servoing from epipolar geometry and projective invariants
Authors: Adachi Jun , Sato Jun 
Published: June 2007

AbstractVisual servoing is being widely investigated as a robot control method that is robust to unpredictable disturbances. Conventional visual servoing assumes calibration of the robot and camera, but such calibration proves very difficult in practice. Thus, we have proposed a method of stable visual servoing for a robot moving on a plane, with neither the robot nor its camera being calibrated. In this paper, we extend the previous method to 3D projective space, thus providing visual servoing for general uncalibrated robots operated in 3D space. In particular, we show that invariant properties in projective space defined by means of epipolar geometry play an important role in navigation. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 90(12): 50–58, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.20361
Sensorless control of synchronous reluctance motors based on extended electromotive force model and inductance measurement
Authors: Ichikawa Shinji , Tomita Mutuwo , Doki Shinji , Okuma Shigeru 
Published: June 2007

AbstractIn this paper, sensorless control for synchronous reluctance motors (SynRMs) without signal injection and an inductance measurement for position estimation are proposed. In the case of SynRMs, accuracy of inductances is the most important factor in realizing precise position estimation because inductances are largely varied by a magnetic saturation phenomenon. Therefore, the inductance measurement method, which can measure appropriate inductances for position estimation, is important as well as a sensorless control method. The inductance measurement based on the observer is discussed, and the measurement method and the parameter adjustment method for improved stability of the closed loop are proposed. The proposed method can measure inductances easily and be applied for permanent magnet synchronous motors, too. Finally, the proposed sensorless control method is verified experimentally. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 70– 80, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ eej.20274
An analysis of shielding against DC magnetic fields generated by electric railways. Evaluation of effective permeability of fine structure
Authors: Waki Hiroshi , Igarashi Hajime , Phonma Toshihisa 
Published: June 2007

AbstractThis paper describes an effective analysis of magnetic shielding based on homogenization. The analyses become time‐consuming if the problems include the magnetic substances having fine structure. The homogenization of the structure makes it possible to analyze effectively the magnetic fields. The authors introduce a method to estimate the effective permeability of the homogenized substance. This method can be applied to any periodic structure made of magnetic substance. The magnetic shielding effects by the structures against direct‐current (DC) fields generated by electric railways are analyzed by using the present method. As a result, it is found that the overhead way and the protective fence near the railway work as a magnetic shield, whose effects can be improved by appropriate arrangement of those constructions. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 7–15, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20310
DC interruption characteristic of vacuum circuit breaker
Authors: Odaka Hiromi , Yamada Masataka , Sakuma Ryohei , Ding Cuie , Kaneko Eiji , Yanabu Satoru 
Published: June 2007

AbstractA high‐speed vacuum circuit breaker (HSVCB) has been investigated. HSVCB makes high‐frequency current superimposed on a fault current so that the current is forced to be zero and is interrupted. Its interruption performance is considered to be dependent on the rate of change of the current (di/dt). As a fundamental research, we investigated the di/dt– dv/dt characteristics and the insulation recovery characteristic after interrupting the counter‐pulse current for various contact materials of AgWC, CuW, and CuCr. The results revealed that the case where the gap length is larger is better in a current interruption performance. Moreover, it was found that di/dt is not dependent on the insulation recovery characteristics, but the magnitude of interruption current is of great influence. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 17– 25, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20362
3D numerical analysis and test results of a short‐primary linear reluctance motor
Authors: Ogawa Kokichi , Higuchi Tsuyoshi 
Published: June 2007

AbstractA 3D boundary integral equation is applied to a model of a short‐primary linear reluctance motor. The model is a double‐sided construction where the primary member is surrounded by a set of secondary iron plates on both sides. Six kinds of different secondary geometries are calculated and their characteristics are discussed. For the confirmation of calculation results, a test machine is manufactured. Test results are compared with calculated ones. Furthermore, the static thrusts of a single‐sided machine and a coreless PMLSM are measured and compared with those of the double‐sided machine. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 58–65, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20390
A large generator's bids in an electricity supply auction: Uniform pricing versus pay‐as‐bid pricing
Authors: Yamamoto Yoshihiro , Tezuka Etsuo 
Published: June 2007

AbstractA pay‐as‐bid auction has been adopted in a balancing market under New Electricity Trading Arrangements in England and Wales since 2001 instead of a uniform price auction previously used in a day‐ahead pool market. In contrast, a spot market in Japan, where a general electric utility would be the main supplier, plans to employ a uniform price auction. In this paper we model an electricity spot market in which one large generator competes with many fringe generators to supply electricity, analyze how this large generator bids to maximize its profits, and report some implications for the design of this market. Three types of auction are analyzed: a highest‐winning‐bid pricing (HWB) uniform price auction, a lowest‐losing‐bid pricing (LLB) uniform price auction, and a pay‐as‐bid auction. It is shown that the slope of the bid curve, which is obtained by plotting the large generator's bidding prices against its generation costs, are steeper in an LLB uniform price auction and flatter in a pay‐as‐bid auction than those in an HWB uniform price auction. This implies that an LLB uniform price auction or a pay‐as‐bid auction would make room for the fringe generators to win an auction. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 41–48, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20420
A study of generator system selection for large wind turbine generator system
Authors: Kimura Mamoru , Ide Kazumasa , Nishihama Kazuo , Futami Motoo , Ichinose Masaya , Fujigaki Tetsuo , Iizuka Motonobu , Imaie Kazuhiro , Yagi Yasuomi , Tamura Jyunji 
Published: June 2007

AbstractThis paper focuses on selection of wind turbine generation systems that include generators, converters, and gears. We study three systems: a permanent magnet generator (PMG) system, a doubly‐fed generator (DFG) system, and a synchronous generator (SYG) system in terms of the system efficiencies and running costs. The system efficiencies and running costs are calculated by considering the relationship between wind power and wind conditions. According to these results, the one‐step gear PMG system is the best choice for a large wind turbine system. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 51–57, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20506
Rotation‐invariant image matching by geometrical parameter of equidistant edge pixel group
Authors: Hayashi Hiroki , Saitoh Fumihiko 
Published: June 2007

AbstractTemplate matching is a method of searching for a target image area that is similar to a template image. However, the target image area generally must have the right position relative to the template image. Therefore, the computational cost is high when the location and the inclination of the target image area are unknown. This paper proposes a method of searching for a target image area with arbitrary location and an arbitrary inclination by means of geometrical parameters obtained by an equidistant edge group. In this method, the difference of directions is calculated from the edge direction of a referenced edge pixel and from the directions from the referenced edge pixel to other selected edge pixels. After that, matching is performed, using the difference in directions and the matching rates are accumulated. Then the location and inclination of the target image area are sought by scanning the accumulation space. Experimental results show that the proposed method has higher reliability and lower computational cost for image matching. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 34–42, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20520
Examination of a digital FLL system design for SQUIDs
Authors: Oyama Daisuke , Kobayashi Koichiro , Simizu Takayuki , Yoshizawa Masahito , Uchikawa Yoshinori 
Published: June 2007

AbstractBiomagnetic field measurements in unshielded environments require both large dynamic range and high slew rate. Noise amplitudes at 50 Hz and under 10 Hz of significantly more than 1µT are not at all exotic in an industrial or a hospital environment. A digital FLL (D‐FLL) system for a SQUID magnetometer has high resolution and large dynamic range of magnetic field. Slew rate of a D‐FLL system by means of a double‐counter is limited by its digital feedback loop. It can increase the slew rate that optimum feedback loop gain is divided into an analog preamplifier and a digital amplifier on a microcontroller. We show the method of design of their amplifiers. The slew rate of a D‐FLL system with optimum amplifiers is 483Φ0/s, and its noise level is about 50.0 fT/√Hz@120 Hz. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 1–6, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20526