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Showing papers by "University of Electro-Communications published in 1984"


Journal ArticleDOI
TL;DR: In this paper, the role of the strain and strain rate gradients in raising the apparent torsion peak strain ep above the ep values obtained from homogeneous tension or compression testing is clarified.

917 citations


Journal ArticleDOI
TL;DR: In this article, the dynamics of naphtosemiquinone and SDS alkyl radicals were studied by CIDEP in a micellar solution and the total emission pattern of the spectrum detected at an early stage after pulsed excitation revealed a predominant contribution of the triplet mechanism.

88 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the Urakawa-Oki earthquake at 0232 UT on 21 March 1982 to detect ionospheric disturbances by a network of HF-Doppler sounders in central Japan.

65 citations


Journal ArticleDOI
TL;DR: In this paper, the cumulative cycle ratio and the empirical distribution function (EDF) under two-stage loading were examined in a similar manner and the cumulative distribution functions (CDFs) generated by stationary unit-jump B-models provided a more comprehensive description of the constant amplitude life data edf, indicating the cumulative damage process is essentially stationary and the specimens have little scatter in their initial damage states.

55 citations


Journal ArticleDOI
TL;DR: Dans cet article, on considere quelques problemes combinatoires et on etablit des problemes «naturels» dans P, pour the reconnaissance dont les limites inferieures en temps polynomial peuvent etre connues.
Abstract: Dans cet article, on considere quelques problemes combinatoires et on etablit des problemes «naturels» dans P, pour la reconnaissance dont les limites inferieures en temps polynomial peuvent etre connues. Introduction du «jeu de galet» et on montre que quelques-uns de ces problemes peuvent etre complets dans certaines classes de complexite

45 citations


Journal ArticleDOI
TL;DR: In this paper, a single drop of liquid nitrogen, oxygen or argon was observed by putting it on a horizontal plate with the room temperature and the measured vibrational frequency was proportional to (wave number) 3/2, and depended in a simple way on the surface tension and the density of the liquid.
Abstract: Vibration of a single drop of liquid nitrogen, oxygen or argon was observed by putting it on a horizontal plate with the room temperature. The drop had a shape of flattened disk and floated on the plate owing to rapid evaporation. It showed a characteristic mode of vibration, namely a standing wave appeared along the periphery and the plane view showed a polygonal shape. As the radius of drop reduced through evaporation, sudden transitions to modes with smaller number of vertices occurred. The measured vibrational frequency was proportional to (wave number) 3/2 , and depended in a simple way on the surface tension and the density of the liquid.

40 citations


Journal ArticleDOI
TL;DR: In this article, an improved method of calculating the linewidth of a laser oscillator due to phase noise is proposed, where the fluctuation in the output amplitude that leads to the phase diffusion is calculated as the amplified thermal and the quantum noise which are delta-correlated in time.
Abstract: An improved method of calculating the linewidth of a laser oscillator due to phase noise is proposed. The fluctuation in the output amplitude that leads to the phase diffusion is calculated as the amplified thermal and the quantum noise which are delta-correlated in time. The saturated gain distribution along the cavity axis that is consistent with the output coupling at the end surfaces is taken into account in calculating the amplification of the noises. The resulting linewidth formula differs somewhat from the conventional formula.

37 citations


Journal ArticleDOI
TL;DR: In this article, numerical analysis of finite element approximation to a nonlinear eigenvalue problem is presented, where the problem arises in MHD (magnetohydrodynamics) equilibria and some other important physical phenomena.
Abstract: This paper presents numerical analysis of finite element approximation to a nonlinear eigenvalue problem: −Δu=λu + in Ω,u=−1 on Γ=∂Ω, where Ω is a bounded domain inR n (n=1, 2, 3). This problem arises in MHD (magnetohydrodynamics) equilibria and some other important physical phenomena. We consider a simple finite element scheme, and perform its error analysis. We also discuss a lumped finite element scheme, which is introduced to simplify the computations of the original scheme. Some numerical results are illustrated to show the validity of the analysis.

27 citations


Journal ArticleDOI
TL;DR: In this paper, the spin resonance spectra of the lowest excited triplet state of 9,10-anthraquinone were detected in a glass matrix at 77 K using a time-resolved technique, and computer simulation trials of the randomly oriented spin-polarized ESR spectra lead to the postulate of a wide distribution of the zero field splitting parameters in the glass.

26 citations


Journal ArticleDOI
TL;DR: In this article, the photoelectrochemical properties of were studied in aqueous electrolytes, and the onset potential of the anodic photocurrent in steady state was found to be about 1V more anodic than that of the photocurrent measured by the lock-in method.
Abstract: The photoelectrochemical properties of were studied in aqueous electrolytes. The onset potential of the anodic photocurrent in steady state was found to be about 1V more anodic than that of the photocurrent measured by the lock‐in method (−2V vs. SCE). This discrepancy was ascribed to the presence of transient photocurrent observed in the potential range between −1.9 and +0.6V vs. SCE. Possible mechanisms of the transient photoresponse were examined. The flatband potential deduced from the Mott‐Schottky plot of the C‐V characteristics was found to shift into the cathodic direction of potential in the course of the photoelectrochemical measurements. The shift was explained by a hypothesis that thin oxide layer grows on the surface during anodic polarization under strong illumination.

26 citations


Journal ArticleDOI
TL;DR: In this paper, the rotational and vibrational parameters of the HCF molecule were obtained for four vibrational levels (0 v 2 0), v 2 = 0-3, v 3 = 0, v 4 = 0.


Journal ArticleDOI
TL;DR: In this article, analysis of Si LVV and CKLL Auger spectra combined with Auger in-depth profiles were carried out for SiC layers formed by the implantation of carbon into silicon.

Journal ArticleDOI
TL;DR: In this paper, the results of restricted Hartree-Fock-type calculation for all-trans polyacetylene (CH)n and linear and bent hydrogen-bonded poly(hydrogen fluoride) (HF)n are mainly reported.
Abstract: Ab initio crystal orbital calculations with extended basis sets and model potentials are performed for one-dimensional periodic systems. The results of restricted Hartree–Fock-type calculation for all-trans polyacetylene (CH)n and linear and bent hydrogen-bonded poly(hydrogen fluoride) (HF)n are mainly reported. The results, in particular total energies per unit cell, are shown to be much more dependent upon the basis sets than on the method of lattice-sum truncation, number of k points, or order of neighbor interactions.

Journal ArticleDOI
TL;DR: The maximum overall CPU server utilization (and the maximum throughput) is achieved by scheduling policy whereby jobs of the class having a shorter mean CPU service time are given preemptive priority over others at the CPU server, although theCPU server utilization is independent of CPU scheduling so long as the set of jobs in the system remains fixed.
Abstract: It has been claimed on the basis of empirical studies that a CPU scheduling policy, whereby I/Obound jobs are given preemptive priority over CPU-bound jobs, produces the highest overall CPU utilization of multiprogrammed computer systems. However, a theoretical result has shown that the CPU utilization is independent of CPU scheduling in a finite-source queuing model of multiprogrammed systems. This paper aims at resolving this seeming conflict and gaining some insight into CPU scheduling by analyzing a Markovian model of job-stream processing. The model studied consists of an infinite backlog of jobs of two classes (a job stream} and a multiple-resource system (the model of a multiprogrammed system which processes the job stream}; the system consists of a cyclic queue of two nodes--a single (CPU) server and an infinite (I/O) server. The system contains a fixed number of jobs concurrently; the values of parameters describing each job class are distinct except for the mean I/O service time. The following result is obtained under the near-complete decomposability of the model: The maximum overall CPU server utilization (and the maximum throughput) is achieved by scheduling policy whereby jobs of the class having a shorter mean CPU service time are given preemptive priority over others at the CPU server, although the CPU server utilization is independent of CPU scheduling so long as the set of jobs in the system remains fixed.

Journal ArticleDOI
TL;DR: In this article, the dc bias field dependence of high frequency dielectric constant from 1 MHz to 100 MHz was measured in the helicoidal smectic C phase of ferroelectric liquid crystal (+)DOBAMBC.
Abstract: Applied field dependence of static dielectric constant, and also dc bias field dependence of high frequency dielectric constant from 1 MHz to 100 MHz are measured in the helicoidal smectic C phase of ferroelectric liquid crystal (+)DOBAMBC. A very low characteristic threshold field, which may be thought as a coerceive field of Goldstone mode, E = 3.8 × 10−3 V/cm (at 82°C) was found in the static dielectric constant measurement by lock in amp and thermal noise method. The high frequency dielectric constant is temperature independent above from 10 MHz. A lucid ⊊ -E hysteresis loop by dc bias field E and its critical behaviour in 50 MHz region are observed.

Journal ArticleDOI
TL;DR: In this paper, a triplet energy transfer from benzophenone to naphthalene and biphenyl was studied in frozen SDS micelles at 77 K using a time-resolved ESR method.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the crystallization rate of vacuum-deposited amorphous antimony (a-Sb) films and showed that the relationship between v and d-1 are convex towards the origin.

Journal ArticleDOI
TL;DR: The direct branching algorithm of [25] is extended by providing a technique called ‘halting’ for dealing with nodes with unbounded degree in the comparison tree by allowing the algorithm to check equivalence of two deterministic pushdown automata when none of them are real-time, but in a certain condition that properly contains a case where one of them is real- time strict.

Journal ArticleDOI
TL;DR: In this paper, the growth and crystallization of amorohous antimony (a-Sb) films deposited onto collodion were studied as a function of the oblique angle Θ of the incident vapour beam with respect to the substrate surface by both electron and optical microscopies.

Journal ArticleDOI
TL;DR: A necessary and sufficient condition for a performance vector consisting of utilization factors or average response times of the processor for the jobs to be achievable by some scheduling strategy is obtained.
Abstract: We study a scheduling problem on a finite-source queueing model which is identical to a two-stage closed Markovian cyclic queue consisting of a single-server "processor" and an infinite-server "terminals"; each job has a distinct mean service time at the processor. We obtain a necessary and sufficient condition for a performance vector consisting of utilization factors or average response times of the processor for the jobs to be achievable by some scheduling strategy. The result is analogous to that obtained by Coffman and Mitrani on infinite-source single-server queues.

Journal ArticleDOI
TL;DR: In this paper, the one-sided upper confidence limit of the probability of failure Pf = Prob (R≤S) is established for the case when both the strength, R, and stress, S, follow normal distributions.

Journal ArticleDOI
TL;DR: In this paper, the authors derived the transmission line equations by which the induced current is excited by the electric field components in the transmission direction and between the lines among the electromagnetic field components.
Abstract: The problem of coupling between the transmission line and the external electromagnetic waves is analyzed more easily and more effectively if it is treated via transmission line theory rather than scattering theory if the cross section of the transmission line is much smaller than the wavelength and the principal mode of the induced current is TEM. This paper derives the transmission line equations by which the induced current is excited by the electric field components in the transmission direction and between the lines among the electromagnetic field components. the relation with the conventional theory, physical meanings and the equivalent circuits are discussed. In the experiment in which a plane wave is used as the external electromagnetic field, the results agree well with the present theory and the validity of the theory is confirmed if the transmission line cross section is extremely small. Further, a compensation method is discussed for the transmission line height for which the principal mode is considered TEM. the theoretical accuracy is shown and the fact that the line width restricts the range of applicability of this theory is confirmed experimentally.

Journal ArticleDOI
TL;DR: In this article, it is shown that the renewal function at an arbitrary level is proportional to the function at a reference level and to the probability that the original process stays above the level.

Journal ArticleDOI
TL;DR: A UV Faraday rotator for the high power KrF laser system and other UV excimer lasers has been developed for the first time in this paper, where a 5 cm long quartz cell filled by pure water has been used.
Abstract: A UV Faraday rotator for the high power KrF laser system and other UV excimer lasers has been developed for the first time. Pure water has high Verdet constant and high transmittance in UV region (up to 190 nm). Ninety degree polarization rotation of a KrF laser beam is obtained by passing through a 5 cm long quartz cell filled by pure water. Quartz rod has also been proved to be equally useful as a Faraday rotator for KrF lasers.

Journal ArticleDOI
TL;DR: It is confirmed that LM-BR-BR間 will not be able to co-operate with PWS-PWS at this point in time.
Abstract: 本論文は, 自立型移動ロボット山彦9号の走行モジュールに関するものである.コンピュータシステムにおいてはモジュール化の概念が極めて重要であるが, このことはロボット設計においても同様である.山彦9号はハードウエアの面でも, ソフトウエアの面でも, モジュール化が図られている.走行モジュール (LM) はROM, RAM, 2個のタイマ, シリアルインターフェイス, モータ, モータ駆動回路, シャフトエンコーダをもつ独立したマイクロコンピュータシステムであり, PWS方式の台車の移動を制御する.LMは山彦9号の頭システム (BR) とシリアル通信を介して情報交換を行い, BRの奴隷として働く.LM-BR間のインターフェイスとしてコマンド体系が定義されている.それはBRからLMへ送られる移動動作等を指定するコマンドと, LMからBRへ送られる (内部状態を知らせたり, コマンド終了のタイミングを知らせるための) 応答から成っている.移動コマンドはLMの両輪の速度を指定し, それによりLMは所望の軌を跡描き, かつコマンドが指定する終了条件が満たされると動作を終了する.LMのソフトウエアは次の3部分から成る.(1) 移動制御プロセス(2) モータサーボプロセス(3) 通信制御プロセス第1と第2のプロセスは5ms毎に呼ばれ, 実時間で規則正しい処理をし, 第3のプロセスは非同期的に起こるBRとの間の双方向通信を司る.移動制御プロセスは速度計算や終了条件判定を行う.最後には実験結果とLMプログラミングの例が含まれている.

Journal ArticleDOI
TL;DR: In this article, a new distribution-free method is proposed for reliability demonstration tests, which is based on the distribution free formula for the upper bound of the probability of failure derived in previous papers.

Journal ArticleDOI
TL;DR: In this paper, the spin-polarized triplet radical pairs produced by the photochemical reaction of triplet benzophenone with aromatic amines were detected in glassy matrices at 77 K using a time-resolved ESR method.

Journal ArticleDOI
TL;DR: Computer simulations have verified that the ALPC system employing the Kalman filter promises high performance and feasibility at the rate of 192 bits/s when applied to handwriting signal encoding.
Abstract: A method of handwriting signal encoding based on adaptive linear predictive coding (ALPC) is studied. The ALPC is a form of DPCM which uses a sequentially adaptive predictor in which a sequential estimation algorithm is used to update predictor coefficients. To improve the estimates of the predictor coefficients in the presence of quantization noise, Kalman filtering has been investigated for its feasibility. This results in improvements of not only the estimation of the predictor coefficients, but the signal-to-quantization-noise ratio (SNR) of the signals reconstructed at the receiver as well. Computer simulations have verified that the ALPC system employing the Kalman filter promises high performance and feasibility at the rate of 192 bits/s when applied to handwriting signal encoding.