bluuebunny/crossref_metadata_2025_split huggingface dataset:
The split‐switching network (SSN): A high‐performance multicast ATM switch
Authors: Awdeh Ra'Ed Y. , Mouftah H. T. 
Published: July 2007

AbstractThis paper proposes a new high‐performance multicast ATM switch architecture. The switch, called thesplit‐switching network(SSN), is based on banyan networks. The SSN achieves multicasting in a way that is non‐typical for banyan‐based switches: copying and routeing of multicast cells are carried out simultaneously and within the same fabric. Thus, cells are copied only when needed as they traverse the switch towards the appropriate output ports. The SSN consists of successive spliting stages, and buffering is provided in front of each stage. The SSN is non‐blocking with complexity of order Nlog2/2N for a switch of sizeN, and is characterized by distributed and parallel control. The throughput‐delay performance of the SSN is shown to be similar to that of a non‐blocking output‐buffering switch under different mixtures of unicast/multicast traffic. In particular, the SSN achieves a maximum throughput of 100 per cent and the cell delay and delay variation remain small for loads just below the maximum throughput.
Performance of adaptive token allocation in the leaky bucket
Authors: Yang Oliver W. W. , Mouftah H. T. , Ko C. P. 
Published: July 2007

AbstractThe leaky bucket is a popular method that can regulate traffic into an ATM broadband network. This paper examines a simple but innovative modification that would also provide priority to access the network. This is done by requiring cells of different classes to obtain different numbers of tokens before receiving their services. As a step further, a dynamic scheme can be used in which the tokens allocated to each class are changed according to the traffic load. Performance evaluations of mean cell delays and cell loss probabilities are obtained to provide insight into the behaviour of the system and to provide guideline for furture design.
ISDN loop extension using a mid span amplifier
Authors: Erker Greg J. , Dodds David E. , Krzymien Witold A. 
Published: July 2007

AbstractThe 5·5 km range of the basic rate ISDN loop has been extended by using a negative impedance amplifier and by using a 2 wire/4 wire (2w/4w) amplifier. The negative impedance amplifier extends the range of the loop by 1·0 km, whereas the 2w/4w amplifier extends the range by 1·5 km at the expense of increased complexity. As part of the amplifer design, a resistor/capacitor network has been developed which closely matches the characteristic impedance of telephone cable. Error rate tests have been conducted using various lengths of cable and an operating ISDN line.
Link failure detection for maintaining session continuity in packet data networks
Authors: Kumar Anurag 
Published: July 2007

AbstractA link failure in the path of a virtual circuit in a packet data network will lead to premature disconnection of the circuit by the end‐points. A soft failure will result in degraded throughout over the virtual circuit. If these failures can be detected quickly and reliably, then appropriate rerouteing strategies can automatically reroute the virtual circuits that use the failed facility.In this paper, we develop a methodology for analysing and designing failure detection schemes for digital facilites. Based on errored second data, we develop a Markov model for the error and failure behaviour of a T1T1 carrier, the lowest level in the plesiochronous digital carrier hierarchy in the United States. AT1 carrier has a payload of 24 64Kbps PCM channels.
trunk. The performance of a detection scheme is characterized by its false alarm probability and the detection delay. Using the Markov model, we analyse the performance of detection schemes that use physical layer or link layer information. The schemes basically rely upon detecting the occurrence of severely errored seconds (SESs). A failure is declared when a counter, that is driven by the occurrence of SESs, reaches a certain threshold.For hard failures, the design problem reduces to a proper choice of the threshold at which failure is declared, and on the connection. reattempt parameters of the virtual circuit end‐point session recovery procedures. For soft failures, the performance of a detection scheme depends, in addition, on how long and how frequent the error bursts are in a given failure mode.We also propose and analyse a novel Level 2 detection scheme that relies only upon anomalies observable at Level 2, i.e. CRC failures and idle‐fill flag errors. Our results suggest that Level 2 schemes that perform as well as Level 1 schemes are possible.
On the reachability of discrete‐time compartmental systems with nonnegative input constraints
Authors: Kusuoka Hideo , Maeda Hajime , Kodamas Shinzo 
Published: July 2007

AbstractThis paper investigates the properties of reachable sets of discrete‐time compartmental systems. The discrete‐time compartmental system is characterized by the non‐negativeness of all coefficients of its system state equations and its inputs.The paper first deals with the properties of reachable sets at finite sampling times of general ordinary linear discrete‐time systems with simple non‐negative input, and the n.a.s.c. under which the reachable set coincides with the maximal reachable set at finite sampling times. Then, it deals with the characteristic polynomial representation of state transition matrix and the properties of the maximal reachable set. After showing the properties of reachable sets of compartmental systems, the paper discusses the drug kinetics problem as an example of the analysis of reachable sets.
A new iterative method in numerical pattern synthesis
Authors: Tokumaru Shinobu , Yoshimura Hitoshi 
Published: July 2007

AbstractIn general, in the problem of directivity synthesis, the objective function for optimizing the gain and conditions for constraining the fields of the sidelobe levels must be taken into account together. These kinds of problems had been solved by the so‐called quadratic programming method among other mathematical programming methods, but when the element number becomes large, so must the sidelobe constraint condition number. Thus this method becomes rather difficult in practice.In this paper such a directivity synthesis problem will be formulated as an optimization problem in which Lagrange multipliers will be employed for the objective function which is in quadratic form. Thus, the problem will be solved approximately by introducing Lemez' best‐approximation concept; the solutions will be obtained by use of an extremely simple and rapidly converging iteration‐numerical approach.Although this approach may occasionally yield solutions which are not optimized, its results will be sufficiently close to the optimized solution that it is a practical one. Since, especially, the iteration calculations can be attained by merely considering simultaneous equations, as a computer‐oriented method, this approach can yield solutions more rapidly than the quadratic programming method for a large number of elements.
Contactless measurement of sheet conductivity and mobility of semiconductor wafer by using eddy curent
Authors: Horiguchi Fumio , Furukawas Seijiro , Sugii Toshihiro 
Published: July 2007

AbstractThis paper describes a contactless method for measuring sheet conductivity and mobility of the semiconductor wafer. In comparison with the conventional 4‐probe and van der Pauw methods, no ohmic contacts are needed and therefore no nondestructive measurement error exists. Previously, the quantitative relations of the conductivity and mobility with the distributions of eddy current to be measured and Hall voltage, as well as the voltage for eddy current detection were not clear. In this paper, by considering the mutual inductances between the coil and wafer, these have been clarified. The proposed theory and experimental results are compared and their agreement confirmed. The dependence of the voltage for eddy current detection on frequency is also investigated and optimum frequency for measurement derived. The equivalent circuit is used for Hall voltage detection. Optimized electrode dimensions are shown to exist for maximizing the detection voltage and are verified by experiment. Consequently, this method enables absolute measurements and, concerning the mobility measurement, it has clarified the relationship between the measurement sensitivity and resolving power.
A magnetooptic video disk readout method using a pair of polarized laser beams
Authors: Ishii Akira 
Published: July 2007

AbstractA new symbol readout method employing two readout laser beams that intersect at a specified angle on the magnetic medium surface and are orthogonally polarized with respect to each other is proposed. The diffracted light signal is detected in reproducing the FM video signal, that is, it is recorded thermomagnetically on a magnetic film as recording medium (e.g., a rotating disk memory) using magnetooptic effects. The effects of the readout frequency characteristic, and the readout beam defocus are analyzed. The diffracted light of the high‐frequency signal generated by the signal recording track overlaps the zero‐order diffracted light. By adjusting the intersecting angle of the readout laser beams in such a way that sufficient overlapped light is obtained, the higher‐frequency limit of the readout frequency characteristic can be emphasized. Further, in order to obtain flat FM demodulator characteristic, the needed readout frequency characteristic that attenuates linearly in the neighborhood of FM carrier frequency is realized easily by optical means. As a result of greater emphasis on the larger limit the signal‐to‐noise ratio is improved. It is possible to reduce the output of the readout laser light source to less than half, when compared to the conventional magnetooptic readout methods employing a single beam.
Nonreciprocity of saw velocity on a magnetized ferrite substrate
Authors: Shimizu Yasutaka , Hasegawas Ken , Yamada Takashi 
Published: July 2007

AbstractSurface acoustic waves (SAW) propagating on piezoelectric materials are now utilized in practical devices such as filters and signal processing. However, only a few papers were reported on SAW propagation on magnetic materials. In this paper, the propagation characteristics of magnetoelastic Rayleigh waves on the YIG substrate are treated experimentally for the bias configuration where dc magnetic bias field is tangential to the substrate surface and oblique to the direction of propagation. The saturation magnetization of the YIG ferrite used for the experiment is 250 and the Rayleigh waves were excited and received by using ZnO thin‐film transducers. In this configuration, the nonreciprocity of surface wave was observed. Its velocity to the forward direction was found to be different from that in the reverse direction. The maximum amount of nonreciprocity obtained experimentally in this paper was approximately 150 ppm. This value is too small for the application, but the unidirectional transducer, the isolator and the device similar to the circulator may be constructed by using the nonreciprocal characteristics of surface wave velocities.
Characteristics of an optical branching waveguide in linbo3
Authors: Mitsunaga Kazumasa , Masuda Masamitsu , Koyamas Jiro 
Published: July 2007

AbstractThis paper describes a theoretical analysis of branching losses in planar branching waveguides with optical switching is achieved by the optoelectronic effect of Ti‐diffused LiNbO3. An experimental study of the characteristics of the above element shows that, although the guided optical waves are subjected to losses due to various causes, the major loss can be suppressed effectively by taking the branching angle at 1 or less; the major loss is caused by the tilt of the optical equiphase surface and the “blunting” of the branching fork tip. It is possible to obtain an optical switching extinction ratio of ‐20 dB or more. In addition, it becomes obvious that the blunting on the branch front may result in loss increase where no voltage is applied. Furthermore, an experimental element was manufactured to study the practical characteristics of the hereby proposed branching waveguide. The result obtained by the measurement agrees with the estimated characteristics by the analysis.
Design theory of a distortionless nonreflective all‐pass impedance transformer using a nonuniform transmission line
Authors: Ito Chiaki , Kasais Hisashi , Sato Risaburo 
Published: July 2007

AbstractTraditionally, the use of nonuniform transmission lines has been suggested for designing a wideband impedance transformer. However, no rigorous design method has been found. This paper proposes two rigorous methods each for designing distortionless, nonreflective all‐high‐ and low‐impedance transformers which are simple and of minimum attenuation, based on the distortionless conditions of the voltage and current waveforms in a nonuniform transmission line. The methods make only C(x) or L(x) of the primary constants of the transmission line uniform. It was found sufficient that these distributions be of square or inverse square. According to the design method, we designed a 50 to 75 ω transformer which is subsequently modeled by a 100‐stage ladder network. We performed experiments in the dc ‐ 10 MHz frequency domain as well as in the time domain. The experiment has been proceeded in accordance with the theory and the effectiveness of the proposed design method and the validity of the distortionless theory of nonuniform transmission line are proved.
Evidence for the existence of the craik–o'brien effect in human color vision
Authors: Isono Haruo 
Published: July 2007

AbstractIn human vision there occurs an interesting illusion called the Craik‐O'Brien effect. When a counter line has an appropriate distribution of brightness, even though there is no physical contrast, from the contour information a contrast is produced and an object can be seen. It is hoped that this visual phenomenon can be utilized by an engineering application to improve the quality of TV pictures and condensation of the transmission signals In the past, this phenomenon was studied as an illusion of brightness (no color), and the Craik‐O'Brien effect was not found in the case of color. Hence, its characteristics were unclear . Using an electric edge pattern generator and a color CRT, the author has in this case generated monochromatic colors (R, G, B) and hue edge patterns whose luminance is constant but of different colors and hues. The response of the subjects was measured by psychophysical methods. The results proved the existence of the Craik‐O'Brien effect in the case of chromatic counter information and the author elucidated its characteristics. In the case of monochromatic edge patterns, the effect is significant and its basic characteristic is close to that of the brightness Craik‐O'Brien effect. On the other hand, in the case of chromatic edge patterns, although the pattern existed, the contrast produced by the color was less significant when compared with the contrast produced by the brightness and was only a fraction of the contrast produced by the brightness Craik‐O'Brien effect.
Evaluation on dynamic steps of path hunting in t‐s‐t types of switching networks
Authors: Saito Tadao , Inose Hiroshi , Oginos Nagao 
Published: July 2007

AbstractIn a high‐speed PCM switching system, it is possible to achieve low blocking probability and high switching efficiency due to the large number of available time‐division paths between a given inlet and outlet pair. However, in order to achieve high efficiency, the central control processor of the system must perform more intensive path hunting. In conventional switching network design, the efficiency of the network is a prime concern while the control procedure for path hunting is often overlooked. Depending on the type of switching network, the trade‐off between the efficiency of the network and the complexity of the control procedure should be considered. The main purpose of this paper is to evaluate the path hunting procedures for T‐S‐T type of time‐division switching networks. The path hunting procedure will be evaluated on the basis of theoretical analysis and simulation of typical switching networks. It will be shown that there is a trade‐off between the efficiency of the network and the complexity of the control procedure.
Registration techniques on warpage wafer for eb direct writing
Authors: Sugiyama Naoshi , Otsukas Hideo 
Published: July 2007

AbstractIn the manufacture of integrated circuits by electron‐beam direct writing technique, the pattern shift caused by wafer warpage has been corrected by placing the reference mark on entire chips on the wafer and registration has been made for each chip. In the model experiment proposed in this paper, the number of registrations can be reduced significantly if model points are defined on the wafer. The pattern shift can be estimated for the entire wafer surface by the cubic interpolation method using model points and registration results.A high‐voltage, high‐current MOSFET has been realized as a new type of power transistor. Major problems in the development were how to increase the breakdown voltage and how to reduce the on‐resistance. The latter arises from the series resistance in the gate offset region, which is employed to obtain a high breakdown voltage. A structure with a “field‐plate” overhanging the gate electrode is proposed to reduce the series resistance and to increase the breakdown voltage. A one‐dimensional analysis of this structure is given.Important consequences of the field‐plate are that the ion‐implemented region underneath it is pinched‐off and that the pinch‐off voltage can be kept low even at ion‐implementation dosage high enough to reduce the series resistance. Both p‐channel and n‐channel power MOSFET's have been fabricated. Maximum current of 10 A, a drain breakdown voltage of 200 V, and a transconductance of 1 S have been obtained.A theoretical consideration has been given to the performance comparison between the MOSFET and bipolar transistor as power devices based on their operation principles. It is shown that the MOSFET has good prospects in high‐power, high‐speed applications due to its inherent thermal stability and better switching characteristics, but there is still room for technological improvement in its transconductance and on‐resistance.
Computer‐aided design of the norton transformation on reactance bandpass ladder filters
Authors: Hibino Masao , Matsushimas Toshiaki 
Published: July 2007

AbstractThe CAD method for Norton transformation is presented. Norton transformation has been considered as an important process in the reactance bandpass filter design. It is an equivalence transformation process for easy realization of the element of practical filter. The previous method requires certain designer experience and determines the optional element values by iteration and human interaction. This paper presents a method in which the research method is done by random number and no designer experience is ever required. This method conducts Norton transformation automatically. It has made it possible to automate the complete engineering design of the filter. First, the Norton transformation is outlined, the method giving the circuit topology convenient for program is discussed, and based on the method for topology the algorithm is presented. Finally, how to choose several parameters will be investigated for the search method for several examples. Also given is the design example presented in the computer output.
A study of branching phenomena in nonautonomous piecewise‐linear systems with asymmetrical restoring force in the case of the external force with a sum of several harmonics
Authors: Shirao Yoshiaki , Kido Masao , Kaji Nobuyuki , Moritani Takao 
Published: July 2007

AbstractIn the study of nonlinear oscillations, it is well known that, in general, the fundamental harmonic solutions are either in phase with the external force or in opposite phase with it in a lossless system represented by a second‐order differential equation for a single external force. This paper considers a system with asymmetrical restoring force for several external forces. In the following steps, it is shown that there exist solutions in this system which are neither in‐phase nor in opposite phase with the external forces. First, we consider a second‐order system with an asymmetrical restoring force composed of two line segments as an asymmetrical system, and obtain a periodic solution in the same way as in the case of a single external force. The stability of the obtained periodic solution is studied by using Hill's equation and the boundary conditions of the stable and unstable regions are shown clearly. Moreover, the branching phenomena in the boundary are analyzed in four cases. In three of these four cases, there are branching or jump phenomena of the harmonic solutions of fractional orders (2n + 1) /2 (n = 0, 1, 2) due to asymmetry as in the case of a single external force. However, the fourth case shows the branching phenomena of periodic solutions which are neither in‐phase nor in opposite phase with the external forces. The results of numerical analysis and the appropriateness of the analysis are shown.
An analysis of shielded pair cable for tight coupling by conformal mapping and its application to directional couplers
Authors: Kami Yoshio , Nagasawa Yoji , Sato Risaburo , Arakawa Teruaki 
Published: July 2007

AbstractThe shielded cable with close inner conductors is different from the conventional local cable and can be applied to directional couplers. In this paper, for the purpose of obtaining tight coupling, we investigated the cable in which two inner conductors are very close. In particular, we consider the finishing with very fine conductors for small power application. In this case, it is necessary to use a second dielectric in order to maintain the space between the inner conductors, resulting in an inhomogeneous media. For the solution of such a shielded cable pair by quasi‐TEM mode approximation, we use the method of conformal mapping. Also, the measurements of the cable constants and the restrictions of a directional coupler by TEM approximation are described. The approximate equations obtained are applicable to the design of a cable with tight coupling below about 10 dB and the trial production of 3 dB‐ and 5 dB‐cables was proved to be satisfactory. The directional couplers using these cables are possible in practice and we expect to see their application in the VHF and UHF bands.
Microwave transmission‐type dielectric resonator transistor oscillator
Authors: Hayasaka Takeshi , Shinozaki Satoru , Sakamoto Kazuo 
Published: July 2007

AbstractThe step electrode transistor or GaAs Schottky‐barrier field‐effect transistor can oscillate above 6 GHz. A high Q and good temperature‐property dielectric resonator has been developed. Due to the microwave transistor and the dielectric‐resonator, the frequency stability can be made superior and noise characteristics better in the microwave oscillator, and integrable oscillator can be obtained. For the microwave oscillator design, the output power, stability, tunability and noise characteristics must be known. Therefore on using the negative‐resistance of the microwave transistor and transmission type of dielectric resonator, operation is analyzed for the oscillator using the transmission‐type dielectric‐resonator taken as an out‐of‐band resistive termination. First, changes of the oscillation power and frequency at the center frequency due to the negative resistance property are clarified; the frequency stability and oscillation power variations with the resonance frequency spread are considered; also clarified is the relation between the frequency stability and tunability. Finally, the noise comparisons among the above transistors and other solid‐state devices in the 7‐GHz band are presented.