bluuebunny/crossref_metadata_2025_split huggingface dataset:
A construction of vector quantizers for noisy channels
Authors: Kumazawa Hiroyuki , Kasahara Masao , Namekawa Toshihiko 
Published: July 2007

AbstractRecently, vector quantization has become noted as a highly efficient coding method of image and voice data. So far, many of the highly efficient coding problems, or service coding problems, have been studied separately from channel coding problems. This paper reconsiders vector quantization jointly optimizing source coding and channel coding, and proposes a new vector quantizer for noisy channels. Vector quantizers for binary symmetric channels are designed for memoryless Gaussian source, Gauss‐Markov source and the real images, and are compared with the conventional vector quantizer which does not take account of channel errors. As a result, it is shown that the performance of the proposed vector quantizer is improved without adding the redundancy for error correction, and the improvement of the performance of the proposed vector quantizer for noisy channels over the conventional vector quantizer becomes significant for highly correlated sources and longer block length.
An algorithm for resizing polygonal regions and its applications to LSI mask pattern design
Authors: Sato Masao , Tachibana Masayoshi , Ohtsuki Tatsuo 
Published: July 2007

AbstractIn this paper we consider the problem of resizing figures in a digitized XY coordinate plane. the figures are regions closed by line segments parallel to the × or Y axis or line segments at 45° angles to the axes. By resizing we mean that, given the closed regions and a change width, we expand or contract the input regions by the change width. After first proving some theorems on resizing, we propose an algorithm solving the problem in running time 0 (n log n), where n is the number of vertices in the regions. For particular applications we consider examples using the algorithm for verifying compliance with design rules for the smallest feature size and spacing in a mask pattern, and also the compensation for characteristic machine error in pattern generators, apertures, etc.
Timing control circuit for Josephson IK RAM
Authors: Yamauchi Yoshiki , Yamamoto Masafumi , Miyahara Kazunori , Ishida Akira 
Published: July 2007

AbstractToward realization of a fully decoded random access memory (RAM) with Josephson devices, a method of designing and constructing the important timing control circuit employing dc‐powered loop logic is described. In order to obtain high speed and stable read/write operation, an on‐chip timing control circuit for the nondestructive RAMs including decoder, XY‐driver and readout data‐bus employing loop logic is investigated. Positive and negative transition‐edge‐triggered single‐shot pulse generators (POS, NOS) are newly designed for generating the timing signal pulses and the latter are appropriately delayed using the current steering time, thereby providing a very simple, fast and stable timing control circuit. the timing control circuit for a 1K RAM employing 5‐μm Pb‐alloy technology was designed and proper operation confirmed by an experimental read access time of 3.3 ns.
Synthesis of linear model‐following systems using measured output feedback
Authors: Yasuda Yutaka 
Published: July 2007

AbstractThis paper assumes a situation where the state of a plant cannot be measured directly, and discusses the problem to construct the internally stable model‐following linear system without using a state observer. the problem consists in constructing a compensator (dynamic compensator plus feedback) for the plant so that the transfer function matrix of the obtained closed‐loop coincided with that of the model, and the closed‐loop system (the model‐following system) is internally stable. This paper shows the necessary and sufficient condition for the problem to be solvable, using a geometric approach, and a construction method is presented for the stable model‐following system without using an observer. In contrast to the existing methods, the construction method proposed by this paper does not require any additional condition, and can construct the stable model‐following system with the given parameters without repeating the trial‐and‐error procedures.
Radiation mechanism of perfectly conducting antennas ‐ an interpretation using Nukiyama's vector
Authors: Tokumaru Shinobu 
Published: July 2007

AbstractA problem inherent in discussing the antenna radiation mechanism is that the electromagnetic energy flux density can not be deterministically defined. the practice has been to interpret the Poynting vector as the flux density vector and to use it to explain the various phenomena. In this paper, as the equivalent of the Poynting vector, the Nukiyama vector derived from the energy theorem is interpreted as the flux density vector. This interpretation is applied to the radiation mechanism of a perfectly conducting antenna, and it is shown that the radiation can be explained as “an exchange of energy between the electromagnetic wave radiated into space and the conductor on which the power is impressed, with the energy exchange taking place as the energy transverses the conductor.” It is also shown that the new concept of locally‐stored energy derived from Nukiyama's vector for use in this exposition is a broad concept which also encompasses the representation of observable stored energy as defined by Rhodes.
Optical waveguide analysis using the fourier transform and its application to intersecting waveguides
Authors: Seino Minoru , Nakajima Hirochika , Daido Yoshimasa , Sawaki Ippei , Asama Kunihiko 
Published: July 2007

AbstractIn analyzing inhomogeneous waveguides, this paper derives an analytical method that is effective even for the radiation mode light. Also, the propagation characteristic of intersecting waveguides is studied by using this method. In this analysis, considering virtual waveguides that include the real waveguide completely, the propagating light is expressed by the Fourier transform with virtual modes set up in the virtual waveguides. Moreover, using the concept of the power flow equation, the Helmholtz equation is transformed into a difference equation of Fourier coefficients, where weak coupling and paraxial rays are assumed.Applying this method to intersecting waveguides having inhomogeneous index gradients, we study the dependency of the propagation characteristics of the intersecting angle and the index gradient difference. From these results, light propagation in branching waveguides is found for low intersecting angles. This phenomenon is explained successfully by a model which combines TM0and TM1modes. Furthermore, the propagation characteristics of inhomogeneous waveguides are simulated and their dependency on the index gradient is studied.
Analysis of modulation characteristics of semiconductor laser with lateral field coupling control
Authors: Genei Koichi , Ito Hiromasa , Inaba Humio 
Published: July 2007

AbstractThe internal loss modulation of a semiconductor laser has a very rapid response because it depends on the photon lifetime in an optical cavity. This technique is applicable to high‐frequency modulation and generation of short light impulses which could not be possible by means of ordinary current modulation. the present paper describes some results of small‐signal and large‐signal sinusoidal modulation which are obtained by applying a rate equation to a lateral field coupling control (LFCC) semiconductor laser. It is found that modulation at frequencies higher than 10 GHz is possible and that light impulses with 10‐ps half width can be obtained at several GHz. These results are applicable to other lasers with internal loss modulation.
Infrared laser detection by antenna‐coupled point‐contact schottky diodes
Authors: Inoue Narumi , Yasuoka Yoshizumi 
Published: July 2007

AbstractThe responsivity of antenna‐coupled point‐contact Schottky diodes to CO2 laser radiation was studied experimentally. the very clear antenna‐pattern was obtained for the 10.6 μm radiation and agreed with theory based on the traveling wave antenna. the bias voltage dependence of the detected voltage agreed with the results calculated by using measured dI/dV ‐ V and d2I/dV2 ‐ V characteristics. It is seen from this that the fabricated devices respond to the frequency of a CO2 laser as a square‐law detector (resulting from nonlinearity of the I ‐ V characteristic at CO2 laser frequency) and detect the laser signal by rectification due to the nonlinear current‐voltage characteristic.
Circularly polarized printed array antenna composed of end‐fed strip dipoles and slots
Authors: Ito Koichi 
Published: July 2007

AbstractRecently, many attempts have been made to increase the bandwidth and the gain of circularly polarized antennas constructed on printed circuit boards. In a previous paper, a wide bandwidth was achieved for a circularly polarized array antenna composed of strip dipoles and slots (CP‐PASS), although its actual gain was rather low. In the present paper, the gain of CP‐PASS is enhanced by adopting an end‐fed strip dipole as a strip element, and a basic design procedure and some experimental results of CP‐PASS are shown. First, it is verified by experiments that the end‐fed strip dipole has some advantages; for example, it has a sufficient gain, its crosspolar radiation level is low, and it is easy to control the radiation resistance. Second, an approximate analysis is made for a basic radiating‐element pair for CP‐PASS, and a basic design procedure of CP‐PASS is obtained by applying the analysis. Finally, several CP‐PASS are made and measured, and the design procedure is found to be useful. For a six‐pair CP‐PASS, its actual gain, 3‐dB gain bandwidth, and axial‐ratio bandwidth are about 12 dBi, 11% and 12%, respectively. It is found also that CP‐PASS requires only a slight correction to the element lengths when a reflector is placed. In addition, it is obtained that the gain of CP‐PASS may be increased further.
Synchronous spread‐spectrum multiplex communication system using a modified m‐sequence
Authors: Tanimoto Masayuki , Sumiyoshi Hirotsugu , Komai Mataji 
Published: July 2007

AbstractAlthough the conventional spread‐spectrum communication system has the advantage of asynchronous multiple‐access, the number of simultaneously communicable channels is small due to the interchannel interference and the efficiency of frequency utilization is very low. to deal with this problem, this paper proposes a new synchronous spread‐spectrum multiplex communication system employing a modified M‐sequence. the modified M‐sequence is derived by giving an appropriate dc offset to an M‐sequence so that the sidelobe of its autocorrelation function becomes zero. In this system bitshifted modified M‐sequences are used as spreading codes for each channel and the synchronization among them is maintained. Let N be the length of the spreading code. If a bandwidth N times as large as that required for one channel transmission is used, and the product of the band‐limiting characteristics and the power spectral density of the spreading code satisfies Nyquist's first criterion, multiplex transmission of N channels is realized without interchannel interference. It is proved that equally chosen filters for the transmitter and the receiver to realize the transmission bandwidth restriction maximize the SN ratio due to noise in the transmission channel and the value becomes equal to that in the one‐channel transmission. Therefore, the same number of channels as in TDM is achieved with the same SN ratio and the efficiency of frequency utilization is improved greatly. As for synchronization, almost the same bit synchronization error as in TDM is allowed.
A pair of dipole antennas for controlling polarizations
Authors: Okubo Shigeru , Tokumaru Shinobu 
Published: July 2007

AbstractIn maritime satellite communications, the fading of the satellite direct wave due to interference from sea return waves is a serious problem which causes difficulties in the communications. As a result, methods of reducing the effect of sea return waves have recently been investigated. This paper proposes an antenna configuration that permits such fading effects to be reduced by controlling the polarization for waves in the direction of the sea return wave (we call it “the reserved direction”). At the same time, the polarization loss for the satellite direct wave is made small. the present configuration is composed of a pair of dipole antennas with a reflector. Controls of these wave sources (current distributions) enable us to synthesize the polarization in the reserved direction which is in opposite sense of rotation with that of the sea return wave, has the same axis ratio, and whose major axis is orthogonal to that of the sea return wave in the reserved direction. This reduces the fading effects greatly. Furthermore, even when the antenna shows a movement according to the vessel movement, we have adopted a system which corrects electrically the antenna fluctuation resulting in saving the mechanical altitude stabilizing equipment. We describe first the fundamental characteristics of the present antenna configuration. Wave source characteristics for controlling the polarization in the reserved direction for simple examples have been presented, along with the theoretically computed results of the axis ratio and radiation pattern, etc. Finally, the results of model experiments have been presented to support the theoretical considerations.
Characteristics of pitch period and amplitude perturbation quotients for the detection of glottic cancer
Authors: Kasuya Hideki , Kobayashi Yoshihiko , Kobayashi Takao , Kanazawa Akira , Ebihara Satoshi 
Published: July 2007

AbstractIn an attempt to detect glottic cancer patients by voice information, this paper discusses the properties of the perturbation quotient defined on the pitch period and the amplitude sequences obtained from the outertracheal vibration in the sustained utterance of a vowel. Examinations were made for 42 glottic cancer patients and 39 aged normals. As a result, the following observations were made:

the glottic cancer patients beyond T2 in T‐classification can fairly accurately be detected.
Applying the linear discriminant function to the perturbation quotients, the discrimination score between the glottic cancer and the normal is almost equal to that of a specially trained laryngologist, who listened to the same sample voices and determined the existence of hoarseness.
the perturbation quotient is almost independent of the age of a speaker and the kind of vowels spoken.

This paper describes a new algorithm to estimate accurately the pitch period and the amplitude sequences, as well as the evaluation of the discriminating capability of the perturbation quotients, taking into consideration the variations within the same speaker.
A new recursive structure for very high‐Q digital and SC‐CTD filters
Authors: Takahashi Nobuaki , Inomata Kenji , Takebe Tsuyoshi 
Published: July 2007

AbstractThe second‐order recursive fundamental section up to now, has larger coefficient sensitivities of the amplitude at the filter central frequency and the central angular frequency itself. This makes it difficult to realize high‐Q bandpass characteristics. This paper proposes a new structure with a feedback loop containing sampled‐data filter with medium‐Q bandpass filter and a longtime delay element. When a second‐order bandpass filter is used as the feedback filter, the transfer function of the new structure is a pseudo‐second‐order function. Then the approximate relation is derived between Q of the feedback filter and Q of the new structure filter. the validity of the expression is verified by numerical calculations. It is shown also that when realizing a bandpass filter of the same Q, to what extent the new structure is superior to the traditional second‐order structure from the viewpoints of coefficient sensitivity and round‐off noise. the design procedure for the new structure is shown also. In the digital filter, the long‐time delay can be realized by using a register or a memory. In the analog sampled‐data filter, it is realized by a charge‐transfer device. Thus, the new structure can be realized by a digital filter, or by combining switched capacitor circuits and a charge‐transfer device. Finally, an experimental example of a high‐Q filter by the latter method is shown.
Control algorithms for out‐of‐chain routing in a telephone network
Authors: Fukuda Akira 
Published: July 2007

AbstractWhen part of a telephone network is congested because a different traffic pattern from that designed is offered, attempts are made to improve the network throughput by utilizing other vacant facilities. One such control method is out‐of‐chain routing, which permits calls which overflow from the final in‐chain route under the existing routing scheme (far to near rotation) to be offered to out‐of‐chain routes. Out‐of‐chain routing is expected to improve the network throughput but, on the contrary, it could degrade the network throughput by increasing the traffic toward the alternate route. Therefore a control algorithm for out‐of‐chain routing becomes necessary. This paper first models the switching machine which affects the network overload performance and clarifies the traffic characteristics of three‐node triangle network model when out‐of‐chain routing is permitted unconditionally. As a result, it is clarified that the algorithm which stops routing to the out‐of‐chain routes with office congestion is important. Also, the algorithm which permits out‐of‐chain routing when there is no trunk congestion on out‐of‐chain routes may decrease the throughput compared with the case of no out‐of‐chain routing. the results presented here are confirmed by computer simulation of a laeger network.
Conducted noise measurements of automotive electrical and electronic devices using artificial network
Authors: Yamamoto Shin , Ozeki Osamu 
Published: July 2007

AbstractAs more and more automotive electronic devices have been employed and the level of sophistication of their functions has tended to increase, the needs for further enhancement of reliability of operation in an electromagnetic environment also have been increasing. This paper discusses laboratory measurement methods of RF conducted noise for automotive electrical and electronic devices. Also described are impedance characteristics with power line of six models of Japanese passenger vehicles, suggesting that the impedance can be characterized in three frequency ranges: 10 Hz to 1 kHz; 1 kHz to several megahertz; and several megahertz to 60 MHz. Characteristics of an artificial network simulated power line of the Japanese passenger vehicles are discussed. This paper proposes measurement methods and systems for conducted emission and susceptibility. the proposed system is functional in the 150 kHz ‐ 60 MHz frequency range. In the emission measurement, a histogram of the noise level produced by EUT in the frequency domain can be measured, whereas in the susceptibility measurement system, malfunction modes with EUT, as well as the level of input to cause the EUT to malfunction, can be characterized.
Structures and characteristics of a neural network model for generating circadian rhythm
Authors: Endo Shuji , Kinouchi Yohsuke , Ushita Tomiyuki 
Published: July 2007

AbstractThe biological subject contains a circadian rhythm, which is considered as an autonomous phenomenon originating from its internal structure. the rhythm is known as a biological activity observed in any creature except for prochordata. In most animals, it is found that the circadian rhythm originates from the nervous system. We have discussed the neural network model based on the functions of the neural system, which generate the circadian rhythm. the aim of this paper is to clarify the network structure of the model and to discuss in detail the characteristics through analysis and simulation. It is shown first that the model is composed of two neural oscillators and a neural network with nonlinear transformation characteristics. Then each of the subnetworks is analyzed, describing their basic behaviors. By computer simulation, the entrainment and the change of period are discussed, comparing the result with that of analysis. Those results are compared further with the actual properties of the circadian rhythms of creatures.
Microstrip antennas having posts for circular polarization
Authors: Tokumaru Shinobu , Fukui Satoru 
Published: July 2007

AbstractTo use circular microstrip antennas as circularly polarized radiators, perturbations such as slits are added to resolve degeneracy in the fundamental modes. In this paper, posts are inserted between the circular strip and the ground plane and the degeneracy is resolved. the theoretical investigations of this new circularly polarized microstrip antenna are discussed. In the derivation of the theoretical equations, the field is expanded in terms of Green's functions corresponding to the circular cavity region terminated by an admittance boundary. Numerical examples are given for the frequency characteristics of the axial ratio and the input impedance and for the post dimensions to resolve the degeneracy. the radiation patterns and gains are shown for this antenna. the theory has been confirmed by model experiments.
Fusion splicing between deposited silica waveguides and optical fibers
Authors: Shimizu Nobuo 
Published: July 2007

AbstractAlong with the development of optical circuit elements, the problem of coupling these elements to optical fibers, light sources and detectors is very important in the further realization of highly efficient malfunction optical transmissions systems. In conjunction with the coupling of optical circuit elements to fiber, this paper reports on fusion splicing using the heat of a CO2 gas laser. the circuit elements employ deposited silica waveguide (DS guide), which is excellent with regard to loss, fabrication precision, stability, etc. For coupling of multimode graded‐index fiber to multimode DS guide the average loss of fusion splices was 0.18 dB. Measurement of the reflected light from the splices confirmed that fusion caused the disappearance of reflections. the average loss of fusion splices between single‐mode fiber and single‐mode DS guide was 0.19 dB. A multiple splice of 10 fibers to 10 multimode DS guides spaced 200 μm apart shows the prospect of realizing high‐density multiple fusion splices.
Analysis of single server preemptive priority queues with a renewal process as high‐priority input stream
Authors: Sumita ShüIchi 
Published: July 2007

AbstractThis paper considers a preemptive priority queueing model with two different kinds of priority calls: the inter‐arrival time distributions of high‐priority call and low‐priority call are a general distribution and an exponential distribution, respectively, where the Laplace‐Stieltjes transforms of a general distribution is meromorphic. Both service time distributions are different exponential ones. the service of a high‐priority call begins even if a low‐priority call is under service. Under these assumptions, the mean time in the system of each call is obtained, using the theory of piecewise‐Markov processes. First, the generating functions of steady‐state probabilities of an imbedded Markov chain are derived. Next, by the rate conservation principle of piecewise‐Markov processes, the relation between steady‐state probabilities at a regeneration point and at any time is derived. the average numbers of calls in the system are computed by these probabilities. Further, applying Little's formula to the average number of calls in the system, the mean times in the system are also computed. to evaluate these discussions, it is determined whether these results agree with those of M1, M2/M1, M2/1 preemptive priority queueing models, when the inter‐arrival time distribution of priority call is exponential. Finally, a numerical example is given.