bluuebunny/crossref_metadata_2025_split huggingface dataset:
A crossbar ATM switch for multicast traffic
Authors: Sakuta Makoto , Hiyama Satoshi , Nishino Yoshiyuki , Sasase Iwao 
Published: August 2002

AbstractA crossbar ATM switch for multicast traffic is proposed. First, we propose a crossbar ATM switch to which is added a new state of a switch element capable of performing cell replication at the routing crossbar, with a header translator placed in front of the concentrator following the routing crossbar, as the proposed model 1. By adding minimal faculties to the conventional model, proposed model 1 can cope with multicast traffic without degrading the performance of the conventional model. However, due to treatment of multicast traffic in proposed model 1, output congestion is liable to occur. Furthermore, cells which do not complete cell replication and cell routing at the routing crossbar are sent to the concentrator. That is, the ratio of cells lost by concentration at the concentrator increases and the cell loss probability is degraded. Second, we propose a crossbar ATM switch where the concentrator is removed and all the output lines of the header translator are connected to a shared buffer, as the proposed model 2. We use computer simulations to compare the performance of proposed model 2 with that of proposed model 1 for mixed traffic with unicast and multicast cells with respect to cell loss probability and mean delay. It is shown that proposed model 2 can improve cell loss probability performance dramatically for low and medium loads. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(11): 16–25, 2001
Study of cluster feed system with hybrid low‐level beam‐forming network
Authors: Tokunaga Kyoko , Tsunoda Hiroaki , Yamasa Yasuhiko , Orikasa Teruaki 
Published: August 2002

AbstractCluster feeds have been widely adopted as multibeam antenna feeds for communications satellites because they can realize high edge levels. A low‐level feed system in which amplifiers are connected after beam‐forming networks is especially effective in reducing the feed loss. The beam‐forming network is not required to withstand high powers. This system is promising as a feed system of a multibeam antenna that needs to transmit high power. However, it is difficult to equalize the operational level of amplifiers in a low‐level feed system. This paper proposes a hybrid low‐level feed system that can equalize the operational levels of amplifiers in order to use the amplifiers more efficiently. Analysis shows properties of a design of an antenna that adopted this system. Antenna elements and beam‐forming networks were produced. The primary patterns were measured, and the secondary patterns were calculated using these results. A comparison of the design with the calculation results shows that a multibeam antenna with high gain and low side lobes is realizable with this system. The components into which high power is input, are proved capable of withstanding high power and verified the generated level of PIM. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(11): 35–43, 2001
Identification of propagation path from low antenna height base station in urban area
Authors: Furuno Tatsuo , Taga Tokio 
Published: August 2002

AbstractThe delay spread characteristics in low antenna height propagation in urban areas are difficult to accurately estimate by statistical methods that are highly dependent on the location. To understand how the road system affects the propagation characteristics, the propagation mechanism was analyzed. In practice, the identification of the propagation paths has been attempted by measuring the direction of arrived waves and the delay propagation time (propagation path length) at line‐of‐sight and non‐line‐of‐sight locations. The results clearly showed that many arrived waves are propagated by geometric optical reflections by the walls of buildings, diffractions at the corners of intersections, and their combinations. Furthermore, the calculated results and measurements were compared based on geometric optical methods and wedge diffraction theory to demonstrate the usefulness of geometric optical computational methods. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 84(12): 41–51, 2001
Performance analysis of indoor infrared wireless systems using PPM CDMA
Authors: Ohtsuki Tomoaki 
Published: August 2002

AbstractIndoor infrared wireless systems using pulse position modulation (PPM) code division multiple access (CDMA) have attracted much attention, because PPM CDMA can realize random access with the same wavelength. In addition, PPM CDMA has high power efficiency. The system referred to as PPM CDMA in the field of infrared wireless communications is usually referred to as CDMA with multibits/sequence in the field of optical fiber networks. The interference probability used in the literature on infrared wireless PPM CDMA systems is not applicable, and thus the correct performance of such systems has not been clarified. In this paper, we analyze the correct performance of indoor infrared wireless PPM CDMA systems. We assume a system using APD and use Gaussian approximation for the APD output. We analyze the performance in the chip synchronous case with consideration of APD noise, thermal noise, background noise, and interference noise. We show that indoor infrared wireless PPM CDMA can realize multiple access while reducing the required transmit power, compared with systems using on‐off keying (OOK) CDMA. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(1): 1–10, 2002
A proposal of a vehicle network using intervehicle transmission method
Authors: Yashiro Tomoyuki , Matsushita Yutaka 
Published: August 2002

AbstractIn this paper, a mobile vehicle network is proposed to be utilized for intervehicle communication. A network building method is described based on using spread spectrum communication technique and establishing individual links between each vehicle while combining communication and distance measurement between the vehicles within a defined area. In order to more completely utilize network capability, a new concept of zone is introduced and defined. Along with the explanation of the network building method, the evaluation of practical usage of such networks based on computer simulation techniques is also provided. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(3): 40–50, 2002
A method of SAR measurement using a high‐molecular‐weight gel phantom: On the correspondence of the surface of the clouded region to the surface of equipower absorption
Authors: Hoshina Shinichiro , Miyakawa Michio , Kanai Yasushi , Kashiwa Tatsuya 
Published: August 2002

AbstractAs a method for evaluating the electromagnetic exposure of biological bodies, a visualization technique of the absorbed power inside the phantom using high‐molecular‐weight gel is proposed. Such gel containing a small amount of nonionic surfactants has the property of quickly becoming clouded at a temperature above a certain value. Therefore, it is possible to observe the portion with a temperature increase due to absorption of electromagnetic energy as a clouded region. The surface of the clouded region represents an equitemperature surface indicating the temperature at which the phantom is clouded. Hence, this is basically the equal power absorption surface. However, depending on the influence of the thermal conduction, the shape of the clouded region and the absorption power distribution may not coincide. In this paper, the equality of the clouded region shape and the equal power absorption surface is verified. The measured shape of the clouded region formed inside the phantom and the absorbed power distribution within the phantom derived by the three‐dimensional FD‐TD (Finite‐Difference Time‐Domain) method are compared. In addition, the influence of thermal conduction on the temperature distribution in the phantom is discussed. It is confirmed that the clouded shape caused by electromagnetic wave exposure and the computed equal power absorption surface agree well if the electromagnetic wave illumination time is less than about 1 minute. The validity of this method measuring the amount of electromagnetic wave exposure from the clouded shape is confirmed. © 2001 Scripta Technica, Electron Comm Jpn Pt 1, 85(3): 51–60, 2002
Study of statistical model and power measurement results for distortions due to clipping in SCM optical transmission system
Authors: Maeda Kazuki , Tsukamoto Katsutoshi , Komaki Shouzo 
Published: August 2002

AbstractIn the SCM optical transmissions used in optical CATV, it has been pointed out that the distortion generated by clipping behaves in the same way as impulse noise. In this paper, it is assumed that the distortion due to clipping is generated following the Poisson distribution, with the same characteristics as the band‐limited noise, and it is demonstrated theoretically that the amplitude distribution follows Middleton's class A model. On the other hand, there have been many discussions of the theoretical value of the distortion power due to clipping. This study notes that the measurement of the noise power by the spectrum analyzer essentially contains a measurement error. Using the statistical model for the distortion amplitude derived in this paper, the measurement error is calculated for the case in which the amplitude distribution of the distortion due to clipping follows that of the impulse noise. The calculation result is compared to the measurement results and the amount of correction is theoretically derived for the very large error present in the distortion value indicated by the spectrum analyzer. In the SCM optical transmission used in optical CATV, the measured distortion is smaller than the actual value at the ordinary employed optical modulation index. The difference may sometimes reach 20 dB. When the measured value is corrected for the error by the method presented in this paper, the theoretical value of the distortion by clipping, as obtained from Saleh's expression, is almost entirely adequate. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 13–22, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1114
A 2‐V, 1‐MHz, 7‐bit, third‐order noise shaping A‐D converter
Authors: Terada Jun , Matsuya Yasuyuki 
Published: August 2002

AbstractWith the aim of stabilizing high‐order noise‐shaping circuits, a third‐order swing‐suppression A‐D converter featuring low‐voltage operation and megahertz‐band conversion has been developed. This converter achieves a high S/N ratio without having to insert attenuation coefficients as in conventional integrators. In this design, output from quantizers is fed back to a third integrator input to stabilize the loop, and degradation of the S/N ratio due to stabilizing coefficients is suppressed since their insertion is not needed. This A‐D converter operates at a power‐supply voltage of 2 V, achieves accuracy of 7 and 6 bits at input signal bands of 1 and 2 MHz, respectively, and consumes 45 mW of power. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(4): 1–8, 2001
Initial anomalous diffusion of boron atoms at low‐temperature annealing
Authors: Saito Tomoya , Xia Jianxin , Kim Ryangsu , Aoki Takenori , Kobayashi Hiroyuki , Furuta Yoshikazu , Kamakura Yoshinari , Taniguchi Kenji 
Published: August 2002

AbstractExperiments on the transient enhanced diffusion (TED) of boron in superlattice silicon wafers, for the first time demonstrated the existence of the anomalous enhanced diffusion of boron at the very early stage of low‐temperature annealing at locations situated deeper than the implantation damage zone. It was confirmed that this phenomenon is caused by free self‐interstitial silicon atoms present in the implantation tail region. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(10): 59–64, 2001
DANSE: Dynamically adaptive networking service environment
Authors: Itao Tomoko , Matsuo Masato 
Published: August 2002

AbstractThe DANSE (Dynamically Adaptive Networking Service Environment), which constructs an environment (service environment) for utilizing services over a multimedia network in response to the context and the requirements of a user (the state established by a user), is proposed. The DANSE treats uniformly all service‐constituting elements from hardware to software as network resources (NR), searches the NRs required for the user requirements and context during service execution and allocates them to a service environment by combining these. It proposes a substitute plan which corresponds to the context when no match is found for an NR required by the service required by the user. The user can thus utilize the service environment which combines NRs corresponding to the context without realizing it. In addition, the network can respond to the requirements of the user as much as possible by indicating a substitute plan even in a state in which the service contents could not be realized in the past. In addition, by using the mechanism of the DANSE, a service can be created and provided by specifying the service execution procedure, using the existing NRs. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(11): 30–40, 2001
Series connection of resonant tunneling diodes for eliminating spurious oscillations
Authors: Fujii Tetsu , Boric‐Lubecke Olga , Bae Jongsuck , Mizuno Koji 
Published: August 2002

AbstractResonant tunneling diodes, which have the highest operating frequencies among solid‐state oscillating devices at millimeter and submillimeter wave frequencies, generate spurious low‐frequency oscillations easily. As a method of suppressing spurious oscillation of negative resistance devices, the oscillation devices may be connected in series. In this paper, this approach is applied to resonant tunneling diodes. If two diodes are connected in series, no spurious oscillation is observed in the oscillation output spectrum. The effect of suppression of spurious oscillation is experimentally confirmed. Further, from the output characteristic, it is found that the devices are useful as low‐noise high‐ frequency amplifiers and frequency multipliers. © 2001 Scripta Technica, Electron Comm Jpn Pt 2, 84(12): 17–25, 2001
Information Criteria for Statistical Model Selection
Authors: Shibata Ritei 
Published: August 2002

AbstractIn regard to the selection criteria of various statistical models based on the Kullback–Leibler information content, their characteristics are compared and the importance of distinguishing the use in terms of the objective is pointed out. In regard to references dependent on the asymptotic approximation, it is pointed out by examples that the effectiveness of the approximation is important. In particular, as regards the model for discrete values, the necessity of estimation of the Kullback–Leibler information content is presented based on a method not dependent on an asymptotic approximation such as the bootstrap method. © 2001 Scripta Technica, Electron Comm Jpn Pt 3, 85(4): 32–38, 2002
Decomposition of periodic time‐varying transfer function into phase and amplitude modulation components
Authors: Okumura Makiko , Tanimoto Hiroshi 
Published: August 2002

AbstractA nonlinear circuit with periodic operation, such as a mixer and oscillator, can be modeled as a linear periodic time‐varying circuit by assuming a small‐signal input and output. This paper presents a method by which the transfer function of such a periodic time‐varying circuit can be decomposed into phase and amplitude modulation components. Assuming a small input, the phase modulation component can be interpreted as a result of narrow‐band phase modulation with a small modulation index. Thus, it suffices to consider only the first sideband. As regards the spectrum of the amplitude modulated signal, it suffices to consider only the first sideband, regardless of the modulation index. Thus, the two spectra corresponding to the upper and lower sidebands around the carrier are decomposed into narrow‐band phase and amplitude modulation components, and the transfer function can be decomposed into phase and amplitude modulation components. By this method, it becomes possible to decompose the noise of the mixer and the oscillator into the amplitude noise and the phase, or to simulate AM‐PM conversion. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 85(7): 29–37, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.1105
A study of rotor configuration for IPMSM with concentrated winding considering the iron loss
Authors: Murakami Hiroshi , Honda Yukio , Morimoto Shigeo , Takeda Yoji 
Published: August 2002

AbstractThis paper reports an IPMSM rotor configuration with a concentrated‐winding stator. The inductance of the concentrated winding is greater than that of the distributed winding and the flux density of the concentrated winding contains higher harmonic components. The result is higher winding losses than in the IPMSM with a distributed‐winding stator. We discuss three types of interior magnetic rotor with different saliency ratios. In the lower speed range, the highest‐saliency rotor is effective in decreasing the load current and copper losses. On the other hand, in the higher speed range, the higher‐saliency rotors result in greater iron losses and lower motor efficiency; in this range, the lower‐saliency rotor is effective in decreasing iron losses and increasing motor efficiency. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 139(4): 71–78, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10005
An FDTD analysis of electromagnetic fields caused by electrostatic discharge between metals with ferrite material attachments
Authors: Fujiwara Osamu , Kawaguchi Kei 
Published: August 2002

AbstractThe transient electromagnetic fields due to electrostatic discharge (ESD) between charged metals have wide‐band frequency spectra up to the microwave region, which create a serious malfunction for high‐tech information devices. For the above ESD fields, we previously analyzed them, using the finite‐difference time‐domain (FDTD) method, and showed that the metals enhance the field level according to the metal dimension. From the standpoint of reducing such ESD fields, the electromagnetic fields caused by the spark between the metals with ferrite core attachments were investigated. The FDTD method was also used to compute the ESD fields. An FDTD algorithm for the magnetic field inside the ferrite core was newly derived. The results show that the cores attached near the spark gap considerably reduce the magnetic field level, which is also confirmed experimentally. © 2001 Scripta Technica, Electr Eng Jpn, 138(1): 34–41, 2002
New block diagrams using vector signals in the general frame of reference for AC motors with stator core losses
Authors: Shinnaka Shinji 
Published: August 2002

AbstractThis paper presents new block diagrams for induction and synchronous motors with stator core losses such as eddy‐current and hysteresis losses. The proposed block diagrams succeed in realizing simple and clear configurations with physically meaningful vector signals, which are helpful for understanding motor electromagnetic mechanism and useful for designing controllers for them. Vector signals, which are defined in the general reference frame, are utilized as transfer signals between blocks. The proposed vector‐signal block diagram in the frame can be directly and easily reduced to the one in such a specific frame as a stationary or synchronous frame simply by adding certain constraints to it. Shown are three configurations for induction motor, two for synchronous motors including permanent magnet cylindrical motor, permanent magnet salient‐pole motor, and reluctance motor. © 2001 Scripta Technica, Electr Eng Jpn, 138(2): 59–70, 2002
Properties of liquid jet induced by electrohydrodynamic pumping in dielectric liquids
Authors: Hanaoka Ryoichi , Takata Shinzo , Murakumo Masatoshi , Anzai Hidenobu 
Published: August 2002

AbstractLiquid‐jet phenomena induced by electrohydrodynamical (EHD) pumping were investigated in isothermal dielectric liquids without direct charge injection at a metal/liquid interface. A pseudo‐doughnut to plane electrode system was used to generate an EHD liquid jet, and the liquid jet properties were measured using four different dielectric liquids (which are referred to as DBDN, BCRA, Tr‐Oil, and FS‐Oil in this paper). The maximum velocity and pumping pressure achieved were 1.5 m/s and 5.5 kPa, respectively, at an applied voltage of 23 kV with approximately 2.5 W of electrical power consumption in BCRA. It is considered that this liquid jet is due to pure conduction pumping. This mechanism is associated with heterocharge layers near the electrodes which are based on the process of dissociation and recombination of the electrolytic species. Furthermore, to obtain high directivity of the liquid jet, two special nozzles (herein referred to as a normal nozzle and spiral nozzle) were designed. A highly directed liquid jet was obtained using the spiral nozzle. In this case, the flow pattern was of a spiral structure. It is considered that this spiral jet is produced by both the Coanda effect and the nozzle shape (conical hole). © 2002 Scripta Technica, Electr Eng Jpn, 138(4): 1–9, 2002; DOI 10.1002/eej.1132
An architecture of small‐scaled neuro‐hardware using probabilistically coded pulse neurons
Authors: Kawashima Takeshi , Ishiguro Akio , Okuma Shigeru 
Published: August 2002

AbstractIn this paper, we present an architecture for neuro‐hardware that can be realized in circuits of far smaller scale than in the conventional approach. In order to reduce the scale of the circuits, the architecture employs a new method of computing the membrane potential and the sigmoidal function by encapsulating the probabilistic properties into the relative delay between two pulses. The proposed architecture makes it possible to integrate more than 100 neurons in the latest FPGA chip, which is a 13‐fold miniaturization compared to the conventional architecture. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 139(4): 48–55, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.1168
Imaging characteristics of a new magnetic microprobe with spatial differentiation property
Authors: Sasada Ichiro , Tomonari Toshio , Noda Tamotsu 
Published: August 2002

AbstractA new type of magnetic microprobe by which surface anomalies of magnetic or conductive materials can be detected with enhanced spatial resolution and sensitivity is presented. The probe is fabricated using a pair of thin amorphous wires bent in a U‐shape, on each of which two identical copper wire coils are wound. Four identical coils are connected so as to make a bridge circuit, in which two positively coupled coils on the same wire core are placed on opposite sides of the bridge circuit (with positive mutual coupling). The characteristics of the new probe, including the point spread function (PSF), spatial resolution, and sensitivity, are compared with those of a Dahle microprobe having the same assembly but with the connections of the four coils changed. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 9–16, 2001