bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pole assignment for two‐dimensional systems using a multifunctional observer
Authors: Hinamoto Takao , Maekawa Sadao , Shimonishi Jiro 
Published: July 2007

AbstractThis paper considers the problem of arbitrarily assinging the poles for two‐dimensional (2‐D) systems by means of a dynamic output‐feedback including a multifunctional observer. The Roesser state‐space model is used to represent the 2‐D system in this paper. A method for designing a multifunctional observer is proposed for 2‐D systems and a sufficient condition for arbitrary complex‐number pairs to be assigned as the poles of the closed loop system is also presented. The proposed method has a property that the poles of a multifunctional observer are independent of the characteristics of the closed‐loop system.
Nonlinear oscillations in a series‐resonant circuit with an iron core of highly saturable characteristic
Authors: Kitahara Noriyuki , Ohshima Kenji , Abe Minoru 
Published: July 2007

AbstractWhen ac voltage is impressed on a series‐resonant circuit with a core with third‐order characteristics, the m/n harmonic oscillation is often observed with the frequency in commensurate ratio m/n to the excitation frequency. Also, it sometimes happens that the m/n harmonic oscillation exhibits irregular transitions. For example, it may repeat transitions between unstable 1/2 and 3/5 harmonic oscillations. To characterize these oscillation phenomena, this paper considers the series resonant circuit with a core with highly saturable characteristic, and discusses the nonlinear oscillation when an ac voltage is impressed on the circuit. The fundamental equation for the circuit is derived and a numerical analysis is performed using a transformation method. As a result, it is shown that for a certain range of the system parameters, there exist 1/3 harmonic oscillations, which, by themselves are unstable and have different amplitudes. The two oscillators alternate for each three periods of the excitation voltage, resulting in a stable 2/6 oscillation. The physical interpretation is discussed for this periodic solution between chaos. The validity of the analysis was verified exprimentally by direct observation using an electrical circuit.
Realization method of approximate wave‐digital filter d‐section based on lumped/distributed network
Authors: Tokinaga Shozo 
Published: July 2007

AbstractThis paper proposes a reduction method for the D‐section which realizes the complex attenuation poles in the wave digital filter (WDF) design. The reduction is based on the lumped/distributed network. First, an approximate lumped network (called A2‐section) is introduced for the transmission line (UE) with the length T where Richard's variable u = tanh TS is replaced by the rational function qrs/(p2 + t2S2) (p ± 1.6, q ± 2.8). The A2‐section has a set of complex attenuation poles if the values t, p, q are chosen so far as the attenuation pole s = (± y ± j ± ‐ y2)/2(y = q/t, ± = p/t) is complex. In this case, the A2‐section is called the A2‐section. Then it can be shown that the cascade connection 2‐port of two GA2‐sections and series coils is equivalent to the D‐section, and the D‐section is also approximately equivalent to the 2‐port composed of two UE's and LC elements: By applying the well‐known WDT realization method by Fettweis and Swammy, simultaneously, an approximate but very simple D‐section of WDF is obtained. When the length of UE is small, the deviation of WDF response from the design specification is small. As an example, the design of the WDF bandpass filter is shown and the low coefficient sensitivity property compared to the conventional cascade synthesis method is verified.
Synthesis of multifeedback active filters based on the simulation of LC filters
Authors: Hayahara Etsuro , Takumi Ichi 
Published: July 2007

AbstractThis paper presents a synthesis method for the LC simulation‐type active RC filter. In the proposed method, the second‐order active RC filter, which has been used as the unit section in the traditional cascade structure, is modified into a multifeedback structure. The node equation of the original LC filter is set up and then simulated using the multi‐input circuit for each node voltage, which is a modification of the second‐order active RC circuit. The desired circuit is then obtained. As the original second‐order active RC circuit, Sallen‐Key's network and the SAB circuit of Friend are used in this paper. The design method for the circuit is summarized in a table as the design formula. The low element‐sensitivity property of the resistor‐terminated LC filter is retained in the proposed circuit. In particular, the element sensitivity is low when the relative errors among R‐ and C‐elements are small as in the thin‐film hybrid circuit. Finally, a design example and experimental result are shown for the fifth‐order elliptic filter, verifying that the circuit operates in accordance with the theory.
Analysis of the pull‐in range of phase‐locked loops by the galerkin procedure
Authors: Endo Tetsuro , Tada Kenzo 
Published: July 2007

AbstractNumerous ways to analyze the pull‐in range of the phase‐locked system have been proposed, These include harmonic balance, the phase plane method and numerical analysis. In most of these methods, however, it was difficult to determine the actual pull‐in range with high accuracy. This is because of the limitations in the applicable phase detector characteristics and loop filters, or the need to perform a complex numerical analysis. This paper proposes Galerkin's procedure to determine the pull‐in range of the phase‐locked system, demonstrating that the pull‐in range can be determined with a high accuracy in a relatively simple way. Galerkin's procedure is a method of numerical analysis which can determine the periodic function for the nonlinear ordinary differential equation. By applying the procedure, the periodic solution of the second kind, corresponding to the out‐of‐lock condition of the system, is determined. From the critical input‐output detuning for the solution to exist, the pull‐in range is determined. This method can be applied to any phase‐detector characteristics and loop filters, and by taking higher harmonics into consideration, a highly accurate solution can be determined. In this paper, as examples, the pull‐in ranges are determined for a wide range of natural angular frequency and damping factor, for the phase detector characteristics which are sinusoidal, triangular, tanlock and sawtooth with fast jitter.
A computing method for obtaining derivatives of denominator and numerator of network functions with respect to elements and sensitivity analysis
Authors: Honma Hitoshi , Itoh Kouichi , Sagawa Masahiko 
Published: July 2007

AbstractVarious sensitivities necessary for prediction and evaluation of changes in characteristics of networks due to the changes in the value of elements and for optimization of networks, can be computed by using the derivatives of denominators and numerators of network functions with respect to elements. However, existing computing methods of derivatives are not suitable when the number of elements m is m > n (where the size of the matrix representing the network is n × n), that is, the sensitivity analysis which must be computed with respect to many elements. This paper presents a method to compute higher‐order derivatives of denominators and numerators of digital, analog and switched capacitor networks, using Vlach's redundancy improved method. Also, the proposed method and existing methods are compared with respect to the memory size and the number of multiplications required. It is shown that this method is more effective for analyzing the sensitivity for many elements. Finally, the method is implemented here and applied to several examples for element sensitivity analysis.
Improvement of noise attenuation of autoassociative memory using two‐stepped association procedure
Authors: Murakami Kenji , Aibara Tsunehiro 
Published: July 2007

AbstractBy means of autoassociative memory we can read out (or associate) original complete information from incomplete memorized information. If we assume that incomplete memorized information is made of additive noise and original information, autoassociative memory can be regarded as a noise attenuation filter. In this paper, using the twostepped association procedure we proposed earlier, we compose autoassociative memory and with its characteristics, propose a new method to improve the ability of noise attenuation in associative memory. This method restricts the width of the associative output space by changing the dimensionality of the mediate vectors in the twostepped association procedure in accordance with noise condition. This minimizes the influence of noise on the associative output as long as inferiority of information will not occur. In this paper, to examine the ability of this noise attenuation method, we calculate the mean square error (that is, correctness of association or ability of noise attenuation) of association theoretically and execute the association experiment (computer simulation) using the actual image information as the memorized information. From the results, it is clear that our proposed method has high ability of association (ability of noise attenuation) compared with the conventional methods.
Application methods of variable circuit assignment in satellite communications
Authors: Nakajima Seiichi , Suyama Masato , Usui Yukihiro 
Published: July 2007

AbstractThe satellite circuit has various features which cannot be observed in the terrestrial circuit. From the viewpoint of network construction, a significant feature is that the circuit between terrestrial stations can be modified flexibly. This paper discusses the application and features of the timed pre‐assignment (TPA) and demand assignment (DA), which are methods of the variable circuit assignment of satellite circuit. A problem in TPA is the circuit in use in the circuit group at the time of switching. Assuming the method of sequential group selection and pre‐blockade, the probability is calculated for the circuit to be in use at the time of switching. The result is compared with the method based on rearrangement indicating that the proposed method is more realistic. For DA, the call between stations, the cost of terrestrial detour route and ether parameters are used, and the possible range of application for DA is determined in comparison with the pre‐assignment method (PA), considering the terrestrial circuit. It is indicated that DA has a wider range of applications, even if the terrestrial circuit is considered. The reduction effect of the day‐to‐day traffic variation by DA is analyzed, indicating that one can really expect such a merit. The application ranges for the circuit‐based assignment and the group‐based assignment in DA are described. It is indicated that the circuit‐based assignment is desirable from a realistic viewpoint.
Hierarchical control by functional allotment
Authors: Hagino Kojiro 
Published: July 2007

AbstractMost of the studies in the past on the hierarchical control have been concerned with the computational allotment between higher and lower levels, or among lower levels. In the actual system with a hierarchical structure, however, it often happens that the functional allotment is made between higher and lower levels. From such a viewpoint, the following scheme is considered in this paper. Consider a hierarchical control scheme with a functional allotment between higher and lower levels. The higher‐level controller views the whole system by a macroscopic view, and makes decisions so that the system is optimized from a wide range of viewpoints. Then the instruction is issued toward the lower‐level controller. The lower‐level controller views his own subsystem in detail and makes finer decisions so that the subsystem is optimized, while observing the instruction from the higher level as far as possible. The problem is formulated for the hierarchical control with functional allotment, considering the controllable linear discrete‐time stochastic system with a quadratic cost function. Then a situation is assumed where the information concerning the state estimation and the control input can be exchanged at each time between the higher and lower levels, and an algorithm is derived which can successively determine the control input at each time for the higher‐ and lower‐level controllers. Furthermore, it is shown by a numerical example that the intention of the higher‐level controller is reflected on the actual control by the lower level, by a suitable definition of the cost function of the higher‐level controller.
Duplex modified‐read coding scheme for facsimile transmission of documents
Authors: Tanaka Kiyoshi , Nakamura Yasuhiro , Matsui Kineo 
Published: July 2007

AbstractThis paper proposes a new duplex modified‐READ (MR) coding scheme for transmitting a facsimile picture on which other information can be embedded. When the vertical mode on the coding‐scanning line is coded, the MR coding is carried out by moving the run‐length of a black or white pel using the bit‐series of an information source to be duplexed. This method offers a facsimile picture which has almost the same quality as its original without increasing the quantity of the MR‐coding, and can transmit the second information without notice by a third person. For example, the second information with 2 k to 14 kbytes can be transmitted with one of the CCITT test documents. This is an answer to conventional facsimile systems which have a lack of secrecy. This method also contributes to double the transmission rate so that transmission lines can be used more efficiently.
Influence of pulse interference for fiber‐optic star‐ring lan using optical accessors
Authors: Sasaki Jun , Suzuki Shigeru 
Published: July 2007

AbstractTo realize a ring‐type optical LAN which is affected little by node failure and cable failure and yet is flexible in wiring, a star‐ring LAN with optical accessors within an optical cabinet is proposed. Although the present system has an advantage of realizing a high reliability with a one‐fold ring configuration, the system is susceptible to signal interference in optical accessors. The effect of this signal interference on the transmission quality has been evaluated by means of the equation for the equivalent transmission loss by Tokura et al. However, this equation was derived in the case where the discriminating level is always set at the optimum value of the main signal and is not applicable to a general receiving system which is set at the optimum value of the composite signal.In this paper, a configuration of the star‐ring LAN is proposed first and its advantages are described. Next, an approximate equation for calculation of the equivalent transmission loss is derived for an optical receiver system which is set such that the discrimination level is an optimum value of the composite signal. Further, by means of experiments, the relationship is derived between the degree of interference and the equivalent transmission loss, and the experimental values are compared with the computed results. It is demonstrated that the computed and experimental results agree well. Finally, by the use of the results, the optimum value of the transmission loss of the optical accessors in a star‐ring LAN is determined.
Reflection and transmission of a gaussian beam from an anisotropic dielectric slab
Authors: Sonoda Takahiro , Kozaki Shogo 
Published: July 2007

AbstractThis paper describes the characteristics of reflection and transmission when a three‐dimensional Gaussian beam of fundamental mode is launched into a uniaxially anisotropic dielectric slab in which the optical axis has an arbitrary direction. The Fourier transform and solutions are obtained in integral form. Amplitudes of reflected and transmitted beams are calculated numerically by using FFT. To check the theory, experiment is performed by using laser and calcite. The numerical results are in nearly good agreement with the experimental ones.
Phase‐locked loop with a binary quantized phase and frequency comparator
Authors: Guonai Xu , Mori Sinsaku 
Published: July 2007

AbstractTo suppress the phase jitter in digital PLL as is done in analog PLL, it is necessary to narrow the bandwidth of the loop. On the other hand, the narrow‐band loop has an adverse effect on the range of synchronization and the initial pull‐in. Several proposals have been made to solve this problem [3, 6].This paper proposes a new DPLL to solve the problem using a binary quantized phase and frequency comparator (PFC) composed of a general‐purpose shift register, monostable multivibrators and OR gates. Assuming the same jitter suppression performance, the proposed DPLL can broaden the range of synchronization by several times, compared with the traditional DPLL. The performance of the proposed loop structure is calculated theoretically, and the agreement with the result of experiment is verified.
Received signal level characteristics with adaptive transmitter power control in mobile communications
Authors: Fujii Teruya , Kozono Sigeru 
Published: July 2007

AbstractThe adaptive transmitter power control (ATPC) which controls the transmitter power in accordance with the propagation loss between the base station and a mobile station in the land mobile communication is effective in reducing the interference within a channel and that between the adjacent channels of the base station. Also, the portable mobile station which must be small and lightweight is required to reduce the average power consumption. One of the ATPC methods is the ATPC feedback control in which the up‐ and downlinks can be controlled independently.In this paper, the receiving level probability density function is derived theoretically as the basic characteristics in the case of an ATPC feedback. Finally, the effects on the receiving level profile from the control parameters such as the controlled delay time, maximum amount of control, control step width and control level setting are investigated theoretically and experimentally.
Ray‐tracing analysis of anomalous propagation through horizontally nonuniform surface duct
Authors: Oka Eiichi 
Published: July 2007

AbstractIn a radio communication system using a frequency in the UHF and higher band, the fading due to change of the refractive index profile of the air is a significant problem which must be predicted. In this paper, an analysis using the geometrical optics theory is attempted to determine the propagation characteristics in a nonuniform air in which the refractive index varies in both height and range due to a small‐scale nonuniform air mass occurring in the propagation path.After the refractive index of atmosphere is modified by the Earth‐flattening approximation, the Euler‐Lagrange differential equation is solved directly by numerical means so that the ray path is determined. In regard to low‐layer propagation with transmission and reception heights of less than several hundred meters, an air model was conceived in which a surface duct occurred in a part of the propagation path.The relation of the location and size of the duct along the propagation path to the maximum arrival distance (line‐of‐sight) of the direct ray, divergence and convergence of the direct ray and the reflected ray and the arrival angle at the receiving point was studied in detail. It was found that the maximum arrival distance of the direct ray increases significantly depending on the location of the surface duct if it is small in size, the effect of the ray flux is greater on the convergence of the reflected ray than the divergence of the direct ray, and no significant change in arrival angle is seen at the receiving point for both the direct ray and the reflected ray.
Priority Go‐Back‐N ARQ schemes
Authors: Komatsu Masaharu 
Published: July 2007

AbstractThe go‐back‐N scheme is one of the error control methods in the satellite link. Various improvements have been made on this scheme, and the resulting throughput characteristics and packet delay characteristics have been described. However, in those methods, the priority of the class of the packet to be transmitted is not considered.This paper discusses the go‐back‐N scheme where priority rules are useful when several packets with different priority classes are to be transmitted on the satellite link are introduced. Two priority rules are introduced: nonpreemptive priority queueing and preemptive priority queueing. The go‐back‐N ARQ scheme with those priority rules can easily be realized by adding the packet sort function to the transmitter buffer in the conventional basic go‐back‐N ARQ scheme. The traffic analysis is made of the go‐back‐N ARQ scheme with those two priority rules for an arbitrary number of priority classes, and the packet delay expression is derived for each class. Then by numerical calculation examples, the average packet transmission delay characteristics in the two methods are examined.
Theoretical analysis of a leaky millimeter‐wave antenna consisting of a layered magnetic slab image line with periodic corrugation
Authors: Erkin Sidic , Chang Nion Sock 
Published: July 2007

AbstractIn this paper, a millimeter‐wave antenna is constructed with layered magnetic thin films with different saturation magnetizations placed on a grounded conductor and with a periodic structure on the upper layer interfacing with air. Under the condition in which a dc magnetic field is applied externally, the scanning characteristics and the radiation efficiency of the antenna are analyzed with a perturbation method. In the analysis, the multiple scale method also is applied.From the primary field, the coupling characteristics of the radiation field with the guided field and the incident field are derived while the amplitude transport equation is derived from the secondary field. By means of these results, the expressions for the radiation efficiency and the radiation angle of the antenna are obtained. Numerical calculations are carried out in the millimeter‐wave frequency range so that the magnetic field dependence of the beam scanning angle and the radiation efficiency are investigated.From the numerical results obtained, it is found possible to construct a magnetically tuned millimeter‐wave antenna with a large radiation efficiency and a large beam scanning angle by adjusting the structural parameters of the antenna consisting of two layers of magnetic slabs with different saturation magnetizations.
Hierarchical service control scheme for intelligent network services
Authors: Kondo Yoshitsugu , Sato Kiyomi 
Published: July 2007

AbstractWith the introduction of communication services into business activities, such as telemarketing, customer requirements for these services are becoming more varied. Since communication service has become competitive, quick provision of services has become important.This paper proposes a hierarchical service control scheme aimed at achieving service specification independence and the software architecture of an experimental intelligent network service system based on this new scheme. In the proposed new scheme, elementary functional parts are prepared beforehand and a service is realized using interpreter control based on the information about an execution order of functional parts.To localize modifications in software when a new service is introduced, functional parts are arranged in a hierarchical manner. This experimental system can change complicated service specifications in a few minutes. Processing volume is about half of that for an existing system in which service specification is described by a programming language and service associated data are managed by a common data management program.