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Volume 9 (1973)
- Issue 6 Pages 625-
- Issue 5 Pages 499-
- Issue 4 Pages 373-
- Issue 3 Pages 251-
- Issue 2 Pages 123-
- Issue 1 Pages 1-
Volume 9, Issue 5
Displaying 1-17 of 17 articles from this issue
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Kamekichi SHIBA, Tadashi ICHINOSE, Seiji MIZUMURA1973 Volume 9 Issue 5 Pages 499-503
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA Ventilated Psychrometer, e.g. an Assmann Psychrometer, has two Hg thermometers of high precision to measure dry and wet bulb temperatures. However, in the measurement of relative humidity, it needs the precise value of temperature difference between the dry and wet bulbs and not the temperatures themselves.
The experimental psychrometer here reported has two simple kerosene thermometers, marked only at 3 temperature points (in this experiment, 0°C, 20°C and 35°C) and a common temperature scale board. There are no individual temperature scales attached to each thermometer. The interval length between 2 temperature points on both thermometers is nearly equal (that is, within 2.5% error) to the given length 1 on the common scale board. These details are shown in Fig. 1.
It is theoretically proved that relative humidity can be measured by the experimental psychrometer as accurately as with an Assmann Psychrometer.
Experiments were also carried out to confirm the theory, and the experimental results gave fairly good accuracy.View full abstractDownload PDF (619K) -
Shiro HATA, Hiroshi SHIBATA, Shigeru OMATSU1973 Volume 9 Issue 5 Pages 504-511
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPractically and theoretically, it has become very important to discuss the optimization problems of a complex system with several parameters distributed in space. We have already proposed to apply the methods of functional analysis for solving these problems and studied the derivation of an optimal filter and the construction of an optimal control as independent problems.
In this paper, we shall discuss the optimal control of a combined system which possesses both the observation mechanism and the control devices together. Furthermore, from the physically realizable point of view, we treat a system which is observed on discrete finite subdomains of the spatial domain and controlled on similar ones. And under these conditions, we shall derive the optimal filter and then construct the suboptimal control law by use of the optimal estimated values obtained from the filtering mechanism for the linear distributed parameter system with state-dependent noise. Moreover, we shall examine the separability between estimation and control which must be considered for this case.View full abstractDownload PDF (925K) -
Yasuhiro DOI, Hiroshi NAGATA1973 Volume 9 Issue 5 Pages 512-518
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTwo models for simulating lateral inhibition in the visual process are described. One model, a nonrecurrent type, is composed of a flying spot scanner and dual phototubes with a dully focused wide spot. The area of the spot is divided into two parts, each of which is picked up by each of the two phototubes. The difference of the outputs is displayed on a CRT screen as an intensity modulated pattern. The Mach effect is seen and, by further thresholding the output, edges and terminals of pictures are extracted.
In the second model, a recurrent type, two pairs of CRT and vidicon tubes are interconnected one after another and alternately scanned so as to realize a lateral inhibition having a certain time delay. On a CRT display is seen the Broca-Sulzer effect, and it is shown that an object moving within a certain velocity range can be detected by this model. The second model is considered as an extended one that includes the first model.View full abstractDownload PDF (3344K) -
Hideo HANAFUSA, Hiroshi KAWAGOE1973 Volume 9 Issue 5 Pages 519-525
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with the basic study of the static characteristics of a two-dimensional confined jet amplifier. We assumed a detached parabolic shock wave in front of a receiver port and applied momentum and continuity theory. The location and form of the shock wave are determined by the average Mach number upstream of the shock wave.
The Mach number distributions of supersonic flow are graphically analyzed by a characteristic curve method. By considering the energy dissipation of the shock wave at that location, the relation between the average Mach number and the distance from the nozzle exit is determined. The average Mach number distribution along the jet axis is given by the ratio of the control pressure and the supply pressure.
By using a pitot tube and the Schlieren method, the expansion and contraction cycles of the main jet are observed. The analytical prediction coincides well with the experiment if the number 0.75 is introduced into the supply nozzle contraction coefficient.
The length from the supply nozzle to the receiver port is normalized by the width of the supply nozzle. When it is 2.1 the pressure gain is about 2. The maximum pressure recovery is more than 94 per cent. But negative pressure gain appears when the normalized length is 4.3. The analytical pressure gain and the output characteristics coincide with the experiments. But the pressure recovery of the experiment is a little lower than the analytical result.View full abstractDownload PDF (1540K) -
Satoru FUJISHIGE, Tohru KATAYAMA, Yoshikazu SAWARAGI1973 Volume 9 Issue 5 Pages 526-532
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA minimum variance estimator is derived for linear continuous-time systems with an interrupted observation mechanism which is characterized in terms of the jump Markov process taking on the values of 0 or 1. The approach adopted is that we express the jump Markov process in terms of the initial value and jump times instead of the instantaneous values and then apply Lainiotis' formula regarding the initial value and jump times as unknown system parameters. The resultant optimal algorithm is infinite dimensional, so that feasible approximate estimator algorithms are presented for practical implementation.View full abstractDownload PDF (730K) -
Yoshinao TSURUMI, Eiji IKEDA, Hiroshi KAWARADA1973 Volume 9 Issue 5 Pages 533-537
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn existing digital differetial analyzers, rectangular or trapezoidal integration is generally used as the integration method, in which ΔZ, the output of the integrator, is represented by only a single magnitude bit and a sign bit. It has been reported that if Adams or Runge-Kuttaintegration is used as DDA's integration method, and in addition if ΔZ is more accurately expressed by a register of over ten bits, the level of accuracy becomes much higher. But it seems that there are no reports of a simple and practical constitution of this highly accurate DDA.
In this paper a constitution method for a highly accurate DDA is given. Even when ΔZ is expressed by a regiser of over ten bits, ΔZ does not change by more than three pulses in each iteration of integration. From this fact, a DDA is designed in which the transmission of information between integrators is realized by the amount of change in ΔZ in order to save transmission time. We named this digital differential analyzer HADDA (High Accuracy DDA). It is shown that its calculation speed is as high as that of customary DDA's and moreover, that this constitution is not complicated.
Instead of an actual constitution of this HADDA, the calculation error of the HADDA is investigated by simulation using a digital computer. This shows that the HADDA is highly accurate.View full abstractDownload PDF (623K) -
Sakae SHINOMIYA, Yoshitomo OKADA, Tsugumasa SUTO1973 Volume 9 Issue 5 Pages 538-544
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently dragcup type induction generators with direct current operated as accelerometers are widely used in direct measurement of shaft angular acceleration. In these cases, it is important to obtain accurate calibration data for the actual measurement of acceleration. Many methods for calibrating an accelerometer's performance have been put forward quite well, but they are not yet sufficient.
In this paper, we studied this problem for the case when a universal joint is adopted as the driving unit of a velocity variation. The outline of the discussion about the calibrating method is as follows; (1) An angular velocity variation based on a universal joint occurs two times during one revolution of a shaft (n=2), and its angular acceleration can be calculated by αm=(cosγsin2γ)ω02 on the restricted condition (γ<10°). (2) The calibration data for twice the velocity variation can be obtained easily from the above equation, and the results hold in all cases of n=2. (3) Even if a velocity variation is not equal to n=2, the calibration data can be calculated using Eqs. (19), as the gain constant K and the rotor time constant Lγ/Rγ of the sampled machine can be decided respectively utilizing the values of the above equations when n=2.View full abstractDownload PDF (2266K) -
Sadao MAEKAWA, Takao HINAMOTO1973 Volume 9 Issue 5 Pages 545-552
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes some methods for identification of linear systems using the input and the output information under operating conditions. The linear system is expressed by an impulse response whose sampled values are to be estimated successively as unknown parameters.
These methods are as follows: The same input signal is applied both to the unknown system and to its mathematical model, and the parameters of the model are adjusted succesively so as to minimize the performance criterion, which is the squared difference of the outputs of both systems. And the dynamics of the unknown system is recognized from the model which has approximated sufficiently to the unknown system.
As methods for parameter adjustment, this paper proposes three modified gradient methods which use two-valued signals to yield the parameter adjustment signals in order to reduce the quantity of calculation and simplify the structure in making the hardware, that is; (1) a method quantizing the input signal, (2) a method quantizing the output error signal, (3) a method quantizing both the input signal and the output error signal.
For each proposed method the authors derive the convergence condition of the estimated parameters and the optimum condition for quick convergence and show the results of the digital simulation, which support the described theory.View full abstractDownload PDF (899K) -
Toshitaka SUZUKI, Masao KOBAYASHI1973 Volume 9 Issue 5 Pages 553-559
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with the design and the test results of a new transmission dynamometer for the purpose of measuring static as well as dynamic torque, rpm and power of a shaft in the speed range from 0 to over 10, 000rpm. A torque and rpm transducer consists of two detecting disks fixed to the shaft (torsion bar) separated from each other by an appropriate distance, and facing them two auxiliary detecting disks fixed to a connecting pipe which rotates concentrically to the shaft with constant speed. These four disks, formed to be the same size, are made of non-magnetic material such as SUS-32 stainless steel, and have 30 high permeance tips imbedded radially in their periphery. By the rotation of the disks, voltages are induced in the pick-up coils, which are wound upon the pole pieces of permanent magnets and are arranged to couple magnetically with the pairs of disks. Thus the transducer converts the torsion angle and the rotating speed of the shaft to the phase difference and the frequency of ac voltages.
As the frequency of the signal voltage is proportional to the sum of the rotating speed both of the detecting and the auxiliary disks, the measuring circuit of the dynamometer plays roles of subtracting the frequency corresponding to the rpm of the auxiliary disk from the signal frequency, and of measuring torque and rpm. Power is calculated from these two quantities using a simple electronic multiplier circuit.
Experimental results showed the feasibility of the dynamometer, with an accurary of ±2% or better of f.s. as a torque and a power meter, and ±0.5% as a ratating speed meter.View full abstractDownload PDF (2051K) -
Kinji MORI, Etsujiro SHIMEMURA1973 Volume 9 Issue 5 Pages 560-567
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSGenerally in a large and complex system each controller is unable to get perfect information on the system state, and he has different information from the other controllers. By transmitting his information to the others and communicating it with each other, better performance can be achieved.
Here a linear-quadratic-Gaussian-team problem is considered. The nonclassical information pattern for the team problem may be converted to the classical or to the different types of nonclassical information pattern by transmitting or communicating the information. The optimal linear control gains and the optimal linear estimator gains for each information pattern are derived. In the team problem the optimal linear control laws do not satisfy the separation theorem. A relative value of information for two different information patterns is defined. Compared with the information cost, the relative value of information is utilized to design the information pattern by transmitting or communicating the information. The interplay between the state and the control are discussed for the case where the transmission or communication are corrupted by noise.View full abstractDownload PDF (942K) -
Tsutomu WADA, Akira SHIMIZU, Minoru TAKAGI1973 Volume 9 Issue 5 Pages 568-576
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe effects of some geometric peculiarities of wall-attachment fluidic devices on the attaching jet flow and the switching mechanism were experimentally made clear. And the propriety of the analytical model which has been used for the theoretical study of these devices was investigated.
In this experiment, a large scale model was operated with air and water. In the case of water, the flow pattern was visualized by means of polystyrene granules.
The experimental results can be summarized as follows:
(1) An analytical model of a jet flow attached to a sufficiently long wall, which has been used generally, is not applicable to the case of a relatively short wall length or vent distance and considerably large offset, because the jet flow is affected by the wall end or the vent.
(2) An attaching jet flow never separates from a sufficiently long side wall with a vent, unlike the case of a relatively short wall, though the attachment point moves discontinuously from the upstream wall to the downstream one of the vent by a continuous increase of the control flow rate.
(3) Therefore, the switching mechanism of the vent type device is always the opposite wall switching. But the switching mechanism of this case is more complex in comparison with the case of the device without a vent. In this case the vent effects on the attaching jet have to be considered.
(4) From the view point of the switching of the jet, the shorter vent distance is desirable, but from the view point of the output characteristics of the device, the vent distance has a lower limit in relation to the vent width to shut out the flow through the vent in the no load condition.View full abstractDownload PDF (4412K) -
Hidefumi KOBATAKE1973 Volume 9 Issue 5 Pages 577-587
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a study on the prediction characteristics of the human operator in a manual control system. The task of the operator is to predict the future value of a random signal which is displayed as a two-dimensional waveform. The experiment was designed to answer three sets of questions:
(1) How does the human operator predict the future value of a continuous random signal?
(2) How are the prediction characteristics changed by the nature of a random signal?
(3) How precisely can the human operator predict the future value of a random signal?
Analysis reveals that the prediction characteristics of the human operator are essentially differential ones which are not pure, but with low-pass characteristics. In order to account for the characteristic behavior of the operator, a sampled-data prediction model is proposed, and the validity of the model is also checked. It is found that the human operator changes his prediction characteristics adaptively to keep the system optimal.View full abstractDownload PDF (1307K) -
Tsuneo YOSHIKAWA1973 Volume 9 Issue 5 Pages 588-594
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSOn the basis of a new definition of filters, the order of the minimal-order optimal filters for general discrete-time linear stochastic systems is obtained. A method is also established for constructing a minimal-order optimal filter.View full abstractDownload PDF (880K) -
Teruo KIMOTO, Akira WACHI, Shoji SAKURAI, Mitsuo MIKAMI1973 Volume 9 Issue 5 Pages 595-600
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with a new method for automatic diameter control of a silicon single crystal rod in its growth. For the same purpose, several optical methods have been applied in the past. For example, the meniscus formed between the crystallized and melted material has been measured by using either a radiation pyrometer or industrial television.
In our new method, the weight (W) and the length (L) of a single crystal rod in growth are measured separately without using any optical equipment, and the ratio ΔW/ΔL is controlled to become constant. As the magnitude of the ratio is directly proportional to the sectional area of a single crystal rod, a crystal rod having constant diameter is obtained in its growth.
A new temperature control system is also applied in this method. Using a thermal converter to sense the power of the heater, this heater power is always held constant automatically. If any fluctuation of the power source is observed, the thermal converter starts controlling at once to hold the power of the heater constant. Because the time constant of the heater is greater than that of the thermal converter, the temperature fluctuation of the heater is minimized without using the conventional thermocouple or radiation pyrometer.
In order to weight the crystal rod, we have developed a special sensitive load cell made of unbonded P type silicon strain gauges. The sensitivity of this load cell is more than 1×10-5 of its span, and its hysteresis is very small. A temperature control method is proved more difficult than a pulling speed control method for obtaining automatic diameter control, by the result of measuring the indicial responses of both methods.
By using our new method, the diameter of a crystal rod can be controlled within ±1% of its diameter, and single crystals without dislocation are grown easily.View full abstractDownload PDF (854K) -
Yoshiyuki SAKAWA1973 Volume 9 Issue 5 Pages 601-606
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe Purpose of this paper is to study questions regarding controllability for the distributed-parameter systems described by partial differential equations of parabolic type. Fattorini studied controllability by finitely many functions of time. We also consider this type of controllability for the distributed-parameter systems with control functions appearing in the differential equations as well as in the boundary conditions. Necessary and sufficient conditions for controllability are presented. We give some useful results for designing controllers which make systems controllable. Several examples are worked out.View full abstractDownload PDF (718K) -
Hideo TANAKA, Tetsuji OKUDA, Kiyoji ASAI1973 Volume 9 Issue 5 Pages 607-613
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn recent years, it has become very important to build mathematical models for uncertain situations of systems in the fields of systems control or systems engineering. Among the uncertain situations of systems there are randomness and fuzziness. Probability theory is usually used for the former, but a new concept becomes necessary for the latter. Fuzzy sets were introduced by L.A. Zadeh to provide a concept for this purpose.
Decision-making in a fuzzy environment, which is an important problem in fuzzy systems, was researched by R.E. Bellman and L.A. Zadeh on the basis of the fuzzy sets. In that research an optimal decision is an alternative which attains to the maximum of a membership function of a fuzzy decision.
In this paper, we formulate a fuzzy mathematical programming by introducing the idea of level sets on the basis of the optimal decision. The programming decides also a constraint set, because the constraint set is fuzzy. In this meaning a fuzzy mathematical programming differs from ordinary mathematical programming. This fuzzy mathematical programming may be reduced to ordinary mathematical programming under the two sufficient conditions of the α-continuity and the uniqueness of the optimal level. These two conditions are shown in this paper. An algorithm proposed by the authors may be used to solve the problem in which only the condition of α-continuity exists.View full abstractDownload PDF (948K) -
Jun IKEBE, Oscar A. NAWA1973 Volume 9 Issue 5 Pages 614-621
Published: October 30, 1973
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSScintiscanning is a technique widely employed in nuclear medicine for detecting cancer and other lesions. This paper deals with scanning processes from the probability theory viewpoint.
In order to evaluate the fidelity of the scintigram, the coefficient of variation ε(n)=σ(n)/E(n) is used; σ(n) is the standard deviation, and E(n) is the expectation of the imaging pulses n(t). It was confirmed experimentally that n(t) is a Poisson process, so that in the conventional constant speed brain scanning ε(n) may vary significantly within the cold area, a very important area for analysis.
Based on the fact that the fidelity should be improved by maintaining the coefficient of variation constant, the isocount scanning was devised and realized. By this method, ε(R)=1/√N, where N is a preset constant, is independent of the count rate R over all the observed plane.
This scanning method has been applied to the brain in the clinic of our coworkers.View full abstractDownload PDF (1681K)
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