bluuebunny/crossref_metadata_2025_split huggingface dataset:
A surface acoustic wave resonator on a LiTaO3substrate and its application to video tape recorder oscillators
Authors: Ebata Yasuo , Morishita Shigefumi , Sato Koji 
Published: July 2007

AbstractAn oscillator using a surface acoustic wave resonator is capable of directly generating fundamental frequencies in the region beyond VHF. In this paper, a surface acoustic wave resonator using a reflector consisting of aluminum ridges on a LiTaO3substrate is studied. It is shown that this resonator exhibits a high Q with smaller chip size and has better frequency reproducibility than conventional reflectors on quartz and LiNbO3. A surface acoustic wave resonator having a suitable resonance circuit is designed, using experimental data and results of one analysis of the resonance conditions of the resonant circuit.Finally, a surface acoustic wave resonator suitable for an RF converter IC is designed for application to the oscillator of video tape recorder and is evaluated. the resultant video tape recorder resonator has good reproducibility, suitable for mass production.
Expanded high‐order correlation matrix associative memory
Authors: Ichikawa Atsunobu , Kurogi Shuichi 
Published: July 2007

AbstractAmong the problems concerning correlation matrix‐type associative memory, the limitation of the number of vectors that can be memorized (i.e., memory capacity) was removed by Ichikawa et al. [3] by introducing the idea of high‐order correlation matrix. However, there is a disadvantage in that the required number of memory elements is proportional to the N power of the vector in the N‐th order correlation matrix associative memory. One reason for this is that a redundancy exists in the memorized data due to the symmetrical property of the high‐order correlation matrix. This paper focuses on this point and proposes the expanded high‐order correlation matrix associative memory, aiming at reducing the required number of memory elements. Several aspects of the characteristics of the proposed system are discussed, such as correctness of memory and recall, rate of correct recall, utilization efficiency of memory element, resistance to partial breakdown, and error compensation and correction capabilities. As a result, the following properties are shown:

there exists an order for which correct recall is possible independently of the attribute of the vector to be memorized;
the rate of recall increases with the increase of the order;
the utilization efficiency of the memory element is improved with the increase of the order, but the contribution of the memory element to the recall is independent of the order;
the system is resistant to the partial breakdown of memory, which is a desirable property as a distributed memory;
the error compensation and correction capability increases with the increase of the nonzero components of the input vector and the increase of the order.
Mel Log Spectrum Approximation (MLSA) filter for speech synthesis
Authors: Imai Satoshi , Sumita Kazuo , Furuichi Chieko 
Published: July 2007

AbstractThe spectral envelope of speech can be represented efficiently by the log magnitude spectrum on the nonlinear frequency scale, which is close to mel scale (called mel‐log spectrum). the mel cepstrum defined by its Fourier coefficients is also considered to have a suitable property as the parameter to represent the spectral envelope. So far, no satisfactory filter has been reported for the synthesis approximating the mel‐log spectrum. This paper presents a method of constructing the mel‐log spectrum approximation (MLSA) filter, which has a relatively simple structure and a low coefficient sensitivity, together with a design example of MLSA filter for speech synthesis. the transfer function of MLSA filter is represented by Padé approximation, which approximates the exponential of the transfer function of the filter (so‐called basic filter). Since the transfer function of the basic filter is represented by a polynomial with the transfer function of the first‐order all‐pass filter as the variable, it is necessary in the realization of the filter to delete from the feedback loop the path without a delay. By the construction method of MLSA filter shown in this paper, the path without delay can easily be deleted from the feedback loop in the MLSA filter. the obtained MLSA filter is of relatively simple structure and has low coefficient sensitivity. the quantization characteristics of the coefficient are also satisfactory.
Reliability analysis and preventive maintenance for two‐unit standby redundant system with different failure time distributions
Authors: Sugasawa Yoshio , Kaji Ikuo , Kurihara Masahito 
Published: July 2007

AbstractThe two‐unit standby redundant repairable system considered herein has an operating unit and a standby unit which obey different failure time distributions. A reliability analysis performed when the operating unit is halted and undergoes preventive maintenance and the effect of preventive maintenance for the system are discussed. to avoid system failure caused by preventive maintenance, two practical preventive maintenance policies for an operating unit are considered: (1) Preventive maintenance of an operating unit is made by halting it after a certain operation interval only if the other unit is in standby; and (2) When a standby unit is being repaired (corrective maintenance), another operating unit forfeits preventive maintenance, undergoing preventive maintenance just upon repair completion of the failed unit. This paper also considers the case where two units fail simultaneously. Reliability analysis derives probable quantities by applying Markov renewal processes. the relation between system limiting availability and preventive maintenance and the effect of preventive maintenance for the system are shown by numerical examples.
Carrier‐to‐noise power ratio of a sinusoidal signal transmitted through a nonlinear amplifier
Authors: Mizuno Toshio , Ohkawa Michihisa , Watanabe Tatsuo 
Published: July 2007

AbstractThe characteristics of the detection of a sinusoidal signal transmitted through a nonlinear amplifier having arbitrary AM/AM and AM/PM conversion characteristics is discussed from the viewpoint of the carrier‐to‐noise power ratio, including noise entering at the input and output of the nonlinear amplifier. With both coherent and differentially‐coherent detection, the effect of the AM/AM and AM/PM conversion characteristics of a non‐linear amplifier on the output carrier‐to‐noise ratio is discussed in detail. the carrier‐to‐noise power ratio is derived in closed form. the difference between a TWTA and the effect of a hard limiter is analyzed quantitatively. the results show that the in‐phase carrier‐to‐noise ratio can be improved in both detection methods if the input carrier‐to‐noise ratio is large and the input level is below the saturation point. Under the same conditions the quadrature output carrier‐to‐noise ratio is approximately equal to the input carrier‐to‐noise ratio. With a practical carrier‐to‐noise ratio. AM/PM conversion has little effect on the output carrier‐to‐noise ratio. the carrier‐to‐noise ratio in a channel such as a satellite channel can be determined accurately by measuring the quadrature carrier‐to‐noise ratio of the output of a coherent or differentially‐coherent detector.
Analytical method for multimode oscillators using the averaged potential
Authors: Kuramitsu Masami , Takase Fuyuto 
Published: July 2007

AbstractA method using the averaged potential is proposed for analyzing the oscillation in a multimode negative resistance oscillator. the averaging method is applied to the mixed potential defined by Brayton and Moser and a function called the averaged potential is introduced that expresses the average of the loss (dissipation) of the system. the averaged equations derived by applying the averaging method to the network equations can be expressed as the gradient system of the averaged potential. Hence, stable oscillation corresponds to a minimum of the averaged potential. the analysis of the system is reduced to constructing the averaged potential and to finding the minima. the physical meaning is clarified for the phenomenon of minimal loss of the system in a stable oscillation system. General rules of initiation of nonresonant multimode oscillations are derived because the averaged potential becomes a quadratic form when the chracteristic of an active device is expressed in terms of a polynomial of order three.
Wiener kernels of a system described by ito stochastic differential equation
Authors: Isobe Etsuo , Sato Shunsuke 
Published: July 2007

AbstractWiener analysis of nonlinear systems is now applied to the identification and description of input‐output relationships of systems in engineering and biology. However, since we do not know the relationships between the traditional representations of systems such as a block diagram and a differential equation, and Wiener kernel functions which characterize systems in this analysis, it is difficult to interpret the description of an input‐output relationship by Wiener kernels. Thus a table has been proposed which relates those representations. In this paper, noting that the output of a system represented by Ito stochastic differential equations (which forms one of the nonlinear systems) is a diffusion process, we derive a formula to obtain Wiener kernels by using a transition probability density functions. From the formula we obtain Wiener kernels for a few examples of the differential equation. Also, we discuss the possibility of investigating the input‐output relationships of some feedback systems.
30/20 GHz multiple/shaped beam satellite antenna
Authors: Ueno Kenji , Ando Makoto , Kumazawa Hiroyuki 
Published: July 2007

AbstractThis paper clarifies the design method and radiation characteristic of a satellite antenna (which covers Japanese territory by multiple beams) and a shaped beam simultaneously. This antenna is an offset paraboloidal reflector antenna fed by multiple horns. the main features are the realization of a multiple beam which covers 4‐divided Japanese territory and a shaped beam which is adapted to the form of Japanese territory by one reflector, and the addition of an RF sensor which enables high‐precision pointing direction control.First, a multiple beam antenna and a shaped beam antenna covering the same service area are discussed. It is shown that the optimum reflector parameters are different and a combined multiple/shaped beam antenna covering most of the service area with high gain can be constructed. Next, the RF sensor needed for antenna pointing direction detection is considered. It is shown that the RF sensor can be admitted into the horn cluster for some positions of a beacon station. Finally, from the measurement at the fabricated antenna it is ensured that the increase in primary radiator loss is small due to the multiple/shaped beam sharing and the antenna gain agrees well with designed value. It is clarified that the practical configuration of multiple/shaped beam antenna can actually be realized.
Priority based packet reservation demand assignment TDMA system
Authors: Ono Kinji , Takizuka Takashi 
Published: July 2007

AbstractThis paper proposes a Priority‐based Packet Reservation Demand Assignment TDMA (PR‐TDMA) system by dividing the TDMA channels into two kinds of channels. They are fixed assigned channels and demand assigned channels; in this way it is possible to integrate various communication services such as interactive data, voice, video, file, etc. in satellite packet communications. We have classified the user traffic into three classes. the fixed assigned TDMA channels are used for interactive data and reservation information, while the demand assigned channels are used for bursty file and video, and real time voice transmission by reserving demand assigned channels. the coexistence of two forms of traffic, traffic requiring high speed transmission capacity and traffic requiring time transparency, is made possible by reserving the channels on the basis of slot length and repeated frame period. an access algorithm and an approximate analytic model are described for the evaluation of channel utilization and message delay. Theoretical results are examined by computer simulation and design trade‐offs are considered.
A foundation of information geometry
Authors: Amari Shun‐Ichi 
Published: July 2007

AbstractThis paper proposes a new geometrical basic theory for the field of information science. the traditional theory for the information system is occupied fully by detailed discussions of the properties of a system, and the importance has not been recognized for the mutual relationship within a set of information systems. There are many cases in engineering where a set of information systems must be considered by a single model (for example, in the cases of statistical and system models). to discuss the properties of a model, the mutual relations among the elements must be described. In such a case, the geometrical structure among the information systems, which are elements of the model (e.g., distance, linearity and curvature), is important. This paper recognizes first the family of probability distributions as a manifold. Then it is shown that the structures such as Riemannian metric, α‐pseudo‐distance including a real parameter α, and α‐affine connection, can be introduced naturally. the differential geometrical structure of the space is described. Using the proposed method, the differential geometrical structure inherent in the set of information sources or set of systems can be recognized. the structure is related closely to the system identification problem (parameter estimation), approximation and robustness problems.
Volume‐type multiple hologram memory using PMMA thick films
Authors: Chang Jon‐Chi , Okoshi Takanori 
Published: July 2007

AbstractPhotosensitive polymers such as PMMA (polymethyl methacrylate) are favorable materials for volume‐type hologram; properties of PMMA thick films not studied as yet, will be described in the present report. the validity of a dynamic coupled‐wave theory (in which a saturation effect is considered) is shown. the maximum hologram memory density of a photosensitive particle model is discussed; a differential scattering cross section 0.33 mm2 and maximum photosensitive particle density 3 × 1011/cm3 are obtained. These figures predict a maximum memory density which is an order of magnitude larger than that of a Kodak 649F plate. With a PMMA film several hundreds μm thick the possibility of 100‐fold multiple hologram recording and image reconstruction is confirmed.
A real‐time PARCOR analysis of speech by high‐performance signal processors
Authors: Miyamoto Takanori , Inada Hitomitsu , Nakata Kazuo 
Published: July 2007

AbstractThis paper describes the realization of real‐time PARCOR analysis of speech by digital signal processors. to achieve low bit‐rate transmission of speech a real‐time PARCOR analyzer is developed which can be used as an adjunct to the PARCOR speech synthesis LSI. Especially, new methods are proposed for the detection of speech intervals, determination of voiced/unvoiced sounds, extraction of pitch and automatic correction of the result, which are essential in securing the quality of synthesized speech under the restriction of real‐time analysis. the usefulness of the proposed method is shown by experiment. In order to realize the proposed methods by the newly developed signal processor, the required memory capacity and the effect of computational accuracy are discussed. A means is presented to overcome the restriction. As a result, a single‐board real‐time PARCOR speech analysis‐synthesis system is developed.
Time‐correlation functions of chaotic solutions observed in a certain class of piecewise‐linear difference equations
Authors: Kohda Tohru , Shitanda Kohji , Murao Kenji 
Published: July 2007

AbstractThis paper discusses the time‐correlation function of the chaotic solution (socalled chaos) of the one‐dimensional nonlinear equation. the simplest method to obtain the solution is to calculate directly the trajectory, which, however, requires a large computation time to obtain statistics with sufficient accuracy. From such a viewpoint, recently it was proposed to utilize the eigenfunction expansion of the correlation function by the eigenfunction of Perron‐Frobenius integral operator PT. However, this eigenfunction expansion produces an infinite series and the calculation of the eigenfunction itself is difficult. This makes the method impractical. This paper defines the pseudo‐Boyarsky mapping, which is a kind of piecewise‐linear mapping. It is shown that for this class of mappings, the operator PT. can be replaced by a finite‐dimenisonal matrix P on an appropriately constructed functional space. By this result, the obtained correlation function can be represented by a finite series. the eigen‐function needed in the calculation of the correlation function can be determined by operations in linear algebra.
Analysis of receiving behavior of a window flow control mechanism in packet switching networks
Authors: Tanno Kuninobu , Nakamura Tadao , Sato Risaburou 
Published: July 2007

AbstractThe receiving behavior of a window mechanism, an important function of flow control in packet switching computer networks, is modeled by a 2‐stage tandem queueing system with total capacity limitation. In queueing analysis, it is difficult to obtain analytical solutions for such a limited queueing system because the local balancing equations do not hold. This paper proposes two approximate analytical methods utilizing the state transition rate diagram structure: simple analysis method and heuristic approximation method. the former gives the upper and lower bounds of the steady‐state probabilities of the given system, the latter obtains the approximate analytical solutions directly. the properties of the two methods, applicability and the relation between the two methods, are clarified from numerical and simulated results and it is shown that the two analysis methods are effective approximation methods. Throughput, average system size and average waiting time are calculated and it is shown that the two approximation methods are very useful for evaluating the performance measures of the window mechanism.
Frame synchronization characteristics in degraded bit‐error‐rate conditions and its improvements
Authors: Hata Masayasu , Okunishi Hiroki 
Published: July 2007

AbstractIn this paper, a frame synchronization characteristic and its improvement in degraded bit‐error‐rate conditions (BER = 10−2 ± 10−1) and in the presence of burst errors, are discussed. For the pattern matching type of frame synchronization, an algorithm of two‐frame‐search‐and‐check, in conjunction with the conventional method of allowable bit errors in the detection of sync word, is studied. By regarding the number of allowable errors as design freedom, this paper clarifies the optimum design condition in two‐frame‐search‐and‐check algorithm and its characteristic improvement effect, in comparison with the conventional algorithm. By using this method, the number of backward protection stages is increased equivalently, the holding time when BER is degraded is improved and the allowable burst length is increased by 102 ‐ 105 times. Also, in the reframing characteristic, since the holding of false synchronization is decreased, the reframing time is shortened and the design freedom for the number of allowable errors is extended.
A design of microwave wireless power transmission by the aperture illumination of maximum transmission efficiency
Authors: Uno Toru , Adachi Saburo 
Published: July 2007

AbstractIn the microwave wireless power transmission in the solar power satellite system, it is important to obtain design data on the power transmission. Major consideration is given to the effect of microwaves on the electromagnetic environment, such as biological bodies, communication channel, and ionosphere. In this paper, the aperture illumination of the transmitting antenna for the microwave beam transmission is assumed that maximizes the transmission efficiency, and the maximum receivable power. the power density outside the receiving antenna, with consideration given to the electromagnetic environment, is studied. Under the maximum transmission efficiency, the maximum power density outside the receiving antenna is at the edge of the receiving antenna. Hence, the receivable power is obtained when the power density at the center of the receiving antenna and that outside it are restricted below certain values as an environmental constraint. Thus, a design method can be given for a microwave wireless power transmission system. A fast converging numerical method is given for deriving the aperture illumination for maximum transmission efficiency.
Analysis of the GI/Ek/1 queue with finite waiting room by the supplementary variable approach
Authors: Nogami Shinya , Komota Yasuo , Hoshiko Yukio 
Published: July 2007

AbstractThis paper combines the supplementary variable method and the phase method to analyze the steady‐state of GI/Ek/1 with finite waiting room. Although there have been many studies made on the queue with finite waiting room, there has not been a study of GI/Ek/1which determines the characteristic quantities and discusses the characteristics by numerical computation. This paper defines first the residual arrival time as the supplementary variable and derives steady‐state basic equations for the joint probability density functions of that variable and the total remaining number of phases in the system. Using Laplace transform, the solutions are represented by the joint probability densities for the remaining number of phases and the zero remaining arrival time. the value of joint probability densities is determined, if the distribution function of arrival interval is given, by solving a system of linear equations by numerical computation. Using that solution, various characteristic quantities are represented such as number of customers in the system, actual waiting time, response time, distribution of busy period length, distribution of idle period length, loss probability and power. Finally, the analytical result for GI/M/1/N is found to be equal to the known result, and as a numerical example characteristic quantities of GI/E4/1/4* are illustrated, together with the discussion for the characteristics.
Computer simulation with scale down I2L
Authors: Okada Yutaka , Okabe Takahiro , Nagata Minoru 
Published: July 2007

AbstractScaling down of solid state devices is indispensable for large‐scale integration of circuits. Understanding the characteristic tendency and the limitation of the scaling down provides a useful guideline in recent scaling‐down efforts. This paper discusses scaling down of bipolar transistors, especially the I2L, for which little has been reported. the collector dimension of the I2L is chosen as the scale‐down parameter. Important characteristics such as the current gain, capacitance and delay time are studied by similarly reducing the device with an identical shape from 5 μm to 0.5 μm. In the analysis, the bandgap narrowing effect and the Auger recombination are considered and the two‐dimensional computer simulation program CADDET‐B is used. It is expected that the minimum delay time is reduced to about 200 ps and the power dissipation‐delay time product is improved to about 3 fJ when the collector dimension is scaled down to 0.5 μm.