All issues
Volume 2 (1966)
- Issue 4 Pages 237-
- Issue 3 Pages 165-
- Issue 2 Pages 75-
- Issue 1 Pages 1-
Volume 2, Issue 4
Displaying 1-11 of 11 articles from this issue
- |<
- <
- 1
- >
- >|
-
Mitsuo OTA1966 Volume 2 Issue 4 Pages 237-249
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe need, very often, to measure the joint probability distribution of many correlative random physical quantities in case when we observe simultaneously one or more waves having random phases (like random noise) at two or more different observation points that are different in time, position, frequency or propagation constant. If we call our particular attention to the effect of general correlations among their random physical quantities, it would be well to measure directly the conditional probability distribution rather than the joint probability distribution.
This paper proposes a new method for obtaining sample points of the conditional probability distribution by using the combination of Schmitt trigger circuit and phantastron. We can vary the trigger level in Schmitt trigger circuit and the delay time by use of variable condensers at will. And then, this paper gives a series of photographs prepared to illustrate directly the effect of delay time τ on the wave form of output fluctuation by intensity modulation. Three explicit expressions of conditional probability density distribution for white noise, after passing a mean squaring circuit and an audio band-pass filter of arbitrary width, are experimentally derived in connection with an autocorrelation function of input noise. These are reasonably expressed in terms of Bessel-, Biased Γ-, and Γ-types of distribution.
In this case, the conditional probability distribution for the above output fluctuation is theoretically treated as a probability problem of “distance” in an N-dimensional function space with N=2TW (W: frequency interval, T: time interval), where dsitance is taken as the mean squared fluctuation.
The experimental and theoretical results described in this paper are also applicable to the other fields of measurement on random phenomena, since the mean energy is a universal physical quantity.View full abstractDownload PDF (3669K) -
Suteo TUTUMI1966 Volume 2 Issue 4 Pages 250-256
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPresented in this paper is a new method to measure the optical autocorrelation by the use of simple optical devices with two transparencies having same scales of the two-dimensional functions to be correlated. The experimental results of the photographic autocorrelation obtained by this simple device are shown, and some problems that occur when the autocorrelation of a sample function of a stochastic process is measured by this method are discussed, and consequently another proposed optical autocorrelator with one transparency instead of two is described. an example is discussed to show how to apply the measured two-dimensional autocorrelation for the operation of information processing of an optical detection system, which has been devised by the author.View full abstractDownload PDF (2001K) -
Takayoshi MISAKI, Osamu KATO1966 Volume 2 Issue 4 Pages 257-261
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a method of automatic washing for salt contaminated insulators. An average value of leakage current along the surface of the pilot insulator in a period is detected, for this is a function of the quantity of salt contamination and moisture on the pilot insulator. In each cycle (about 1min. per cycle), the program signals give one by one the instructions on a start and an end of the integration of leakage current, a detection of the integrated value, a stop of the washing action and a reset of the integrator. Here the integrator consists of RC circuit and the detector consists of the silicon controlled rectifier (SCR) whose firing voltage is used as a reference value. If the integrator output proportional to the average value of leakage current rises above the firing voltage of the SCR, a signal of washing is sent to the pump motor or the valve. Then the insulators on line are washed all together during the appointed period.
Finally, by the various experiments this method was proved to have enough accuracy and reliability for practical use. The conclusions are summarized as follows.
(1) An average value of leakage current is justified to be the detecting variable.
(2) The RC circuit used as the integrator is proved to be easy in maintenance.
(3) Because of the fairly short period of the detecting action, the insulator is kept in a sufficiently safe condition under expected environment.View full abstractDownload PDF (2445K) -
Tadashi KIKUCHI, Mamoru MIURA1966 Volume 2 Issue 4 Pages 262-268
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA repetitive type transient analyzer suitable for the measurement of response time of magnetic amplifiers and other various types of pulse-width controlled switching amplifiers is described. It is a simple and reliable electronic device which displays the transient response on the cathode-ray oscilloscope. The response time in cycles is obtained directly by counting the number of cycles referring to the time markers which indicate the phase angle corresponding to the response time of the amplifier under measurement.
A magnetic pulse counter is utilized to produce a stable repeated switching transient synchronized with the a.c. source frequency.View full abstractDownload PDF (2433K) -
Toshiro TERANO, Yahachiro TSUKAMOTO1966 Volume 2 Issue 4 Pages 269-275
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe Gradient Method is the most basic one among the many optimalizing methods and has been studied rather theoretically. The reports of its practical applications are scarece, because there are many difficult problems which must be solved before appling it. There has been no kinetic analysis which shows the quantitative relations among the stability, the settling time, the effects of disturbances and the system-parameters such as the sampling interval, the process time lag, the height of test signal, the proportional gain of adjustment and so on.
This paper is concerned with the theoretical analysis, especially, for the stability problem.
It can be shown that the time lag in the process is a dominant factor on which the system stability depends, and that the stability also depends upon the initial condition since the system has an unstable limit cycle.
Finally some examples by analog simulation are given to examine the theoretical results.View full abstractDownload PDF (821K) -
1966 Volume 2 Issue 4 Pages 275
Published: 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (94K) -
Shigeharu OHCHI, Katsuhisa FURUTA, Keisuke IZAWA1966 Volume 2 Issue 4 Pages 276-282
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSinusoidal perturbation signal has been usually used in optimizing control systems. But the sinusoidal perturbation causes some difficulties or disadvantages, (1) when the process has unknown or variable dynamic characteristics, or (2) when the simultaneous optimization of a multi-variable process is aimed.
Psuedo-random binary perturbation signals can get rid of these disadvantages due to the sinusoidal perturbation.
In this paper, M-sequence signal is used as the pseudo-random binary perturbation signal, and experimental and theoretical study on the optimization of processes with variable dynamic characteristics and on the simultaneous optimization of two-variable processes is described.View full abstractDownload PDF (728K) -
Hiroshi KAWARADA1966 Volume 2 Issue 4 Pages 283-288
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRandom time functions or random numbers having any assigned probability distribution function are generally used in the Monte-Carlo method, simulation problems and other related fields. Therefore it is very important to generate high-speed purely random numbers.
The binary random numbers which are most fundamental are generated from physical fluctuation phenomena or M-sequences. However, these methods are inadequate to generate highspeed binary random numbers, because of the frequency-band limitation of physical noise or of the periodicity of M-sequences.
This paper presents a new method of generating high-speed binary random numbers by combining physical noise and M-sequences. 100kc/s binary random numbers are obtained by sampling the 1Mc/s M-sequence with random pulses which are generated by shaping thyratron noise clipped at a certain voltage level. The auto-correlation function and transition probability of the binary random numbers and the probability distribution function of the pulse-interval of the random pulses are measured. It shows that the properties of 100kc/s binary random numbers are almost purely random.
Finally, key points of speeding up the binary random numbers obtained by this method are discussed.View full abstractDownload PDF (662K) -
1966 Volume 2 Issue 4 Pages 288
Published: 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (102K) -
Yutaka SUZUKI, Tadayoshi FURUYA, Katsuhiko FUJII1966 Volume 2 Issue 4 Pages 289-294
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe dynamic characteristics of a process without self-regulation could not be easily determined from its normal operating records because its impulse response never tends to zero within a finite length of time interval.
In this paper, a method for estimating the indicial response of the process which is not self-regulatory is proposed. By regarding the difference of the outputs which are separated by a certain length of time interval as the fictitious output, the input-output relation of he process can be approximated by a linear algebraic equation with a finite number of coefficients, which correspond to the second difference of the unknown indicial response. These unknown coefficients are easily determined by applying the least squares method. Experiments on an analogue simulator show the practicability of this method.View full abstractDownload PDF (2075K) -
Hiroshi KANAI1966 Volume 2 Issue 4 Pages 295-303
Published: December 30, 1966
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe magnetic field of the electromagnetic flowmeter, which is now used practically, is usually uniform. This type of flowmeter is able to measure any flow rate very accurately as long as the velocity distribution of flow is axially symmetrical. But the sensitivity of this flowmeter varies very greatly as a function of the velocity distribution when the flow velocity is axially non-symmetrical.
The author previously described that the error caused by the axially non-symmetrical flow is made very small when the magnetic field of the flowmeter is suitably distributed.
In this paper, the distribution of the sensitivity in the cross-sectional area of the probe is discussed theoretically and experimentally for various types of probes. One of these probes is suitable for measuring the axially non-symmetrical flow. The sensitivity of this probe varies less than ±6% over most of the cross-sectional area. This value of sensitivity change is about one third of that which is obtained by the uniform magnetic field probe.
The velocity distribution of blood flow, especially in the proximal aorta, is axially nonsymmetrical. This probe is very useful for measurement of such a flow because not only is the sensitivity change very small but also the probe itself con be very small.View full abstractDownload PDF (1902K)
- |<
- <
- 1
- >
- >|