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Volume 27, Issue 10
Displaying 1-17 of 17 articles from this issue
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Yoshizumi WAKASUGI, Hidetaka KOGA1991 Volume 27 Issue 10 Pages 1083-1091
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a new technique for recovering continuous distributions of ventilation as a function of ventilation/volume ratio from observed nitrogen washout curves. The expired nitrogen concentration on each breath is modelled as arising from 50 compartments each having a specific ventilation/volume ratio, and described by a set of linear equations, where the number of equations is equal to the number of breaths, and unknown parameters are ventilations of each compartment.
A parameter estimation problem is formulated based on the method of least squares. The sum of the following two terms is minimized:
1) the residual sum of squares: and
2) the difference sum of squares.
The latter term is added in order to smooth differences of neighboring ventilations with respect to ventilation/volume ratio. The optimum weight for the smoothing term can be theoretically defined according to Akaike's ABIC (A Bayesian Information Criterion).
A numerical method for calculation of the optimum weight is presented, and known distributions with gaussian observation noises are more exactly reproduced than conventional empirical methods. Maximum permissible noise levels of nitrogen washout in order to reproduce bimodal or trimodal distributions are estimated by computer simulation.View full abstractDownload PDF (1077K) -
Yasumasa ITAKURA, Masahiro TAKEUCHI, Masao KASAHARA, Hisanao OGURA1991 Volume 27 Issue 10 Pages 1092-1098
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe spatial filtering velocimetry is useful in the remote sensing of surface velocity of natural turbulent flows. The essential point of this velocity-sensing is to extract the central frequency of the output signal, which is proportional to the mean velocity of the flow. For extracting the central frequency, the spectrum analysis by means of the maximum entropy method (MEM) was applied.
The performance of this sensing associated with the MEM processing was examined with a computer simulation. The random moving image with a spatio-temporal correlation function was generated by a computer software to simulate various turbulent flows. The spatial filtering of the artifitial random moving images generated the temporal output signal by using the parallel slit reticle. Followings were shown by this simulation: (1) for an artificial random flow having a known component of constant velocity, the estimated error of the velocity in the case that the order number (m) of the MEM processing was 10 was smaller than other cases of m=5, 15, 20 or 25, and (2) for a flow having a time-varing velocity component, the accuracy of the measurement was about 5% in the case of m=10.
This sensing method was successfully used for measuring the surface velocity of debris flows spontaneously occured at Kamikamihori Rabin of Kamikochi.View full abstractDownload PDF (1721K) -
Susumu IKEDA, Keizaburo UCHIKAWA1991 Volume 27 Issue 10 Pages 1099-1105
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSTo obtain the accurate values of five parameters in the equation of damped oscillation of balance beam, the time interval measuring method is theoretically extended, which was developed for esitimating four parameters in the equation of undamped oscillation. A method of successive approximation for estimating the five parameters based on the five time intervals at every period is developed, with the aid of a personal computer. According to a numerical simulation, the estimated values except the attenuation constant are in good agreement with the given values within 10-4 at the 4th approximation.
The discussion is also described on better conditions for the time interval measurements.View full abstractDownload PDF (844K) -
Naoki KAMEGAI, Hiromitsu OHMORI, Akira SANO, Yoshihiko MIYASATO1991 Volume 27 Issue 10 Pages 1106-1114
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIdentification of an impulse response by using strongly correlated input signals is a typical ill-posed least squares estimation problem. To attain stability of identification, we consider a weighted squares error criterion in which we can take into account various types of derivative smoothness of the estimated response in time and frequency domains. In order to discuss optimal regularization and truncation in a unified way, we take the generalized singular value decomposition (GSVD) in which we utilize multiple regularization parameters efficiently. On the Bayesian statistical approach we will give a new information theoretic criterion for determining the optimal regularization parameters. By applying the proposed scheme for regularization we can identify oscillatory peaks outside the frequency range of the input power spectrum, even if the PE condition is not satisfied or even when the number of input-ouput data is less than the length of an impulse response to be identified.View full abstractDownload PDF (1119K) -
Eitaku NOBUYAMA, Toshiyuki KITAMORI1991 Volume 27 Issue 10 Pages 1115-1122
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with parametrizing the set of all stabilizing compensators in time-delay systems. In this paper, two definitions of stability are adopted for closed-loop stability; asymptotic stability in the ordinary sense (in which case the closed-loop system has possibly infinitely many spectra) and finite-spectral stability (which is asymptotic stability with the closed-loop system having only finitely many spectra). The main objective is to parametrize each set of all stabilizing compensators corresponding to the definitions of closed-loop stability.View full abstractDownload PDF (1106K) -
Shigeto OUCHI, Tsutomu MITA1991 Volume 27 Issue 10 Pages 1123-1130
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSMany interesting results have been obtained in the studies of H∞ control theory. However, since any compensator of H∞ control has much freedom, we want to know how to utilize the free parameters for other control purposes. In this paper the free parameters of the state feedback H∞ controller are used to optimize an H2 control criterion. As the results, we will show the control structure of the H∞/H2 control system and the role of the H∞ control in the HH2 control loop.View full abstractDownload PDF (953K) -
1-Block ProblemsYoshito OHTA, Hajime MAEDA, Shinzo KODAMA1991 Volume 27 Issue 10 Pages 1131-1137
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper considers the problem of l1-optimal control of multi-input multi-output systems. Specifically, an optimal solution of the so called 1-block problem is given using the duality theorem. It is shown that a linear programming equivalent to the dual problem is derived from the state space representation of weight functions. Using an optimal solution of the dual problem, an optimal solution of the primal problem is constructed. An advantage of the method as compared to an existent one is that it avoids calculating the zeros and their directions of transfer functions, and hence it is computer-oriented.View full abstractDownload PDF (855K) -
Estimation of Damped Oscillating System Parameters and Input Waveforms by Complex First Order SystemNobuharu AOSHIMA1991 Volume 27 Issue 10 Pages 1138-1143
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSComplex first order system (CFOS) is applied to simultaneous estimation of system parameters and input waveform from the observed output waveform. This is based on the following properties; (1) An initial value response of CFOS is same as the impulse response of the same CFOS except a complex multiple factor. (2) Responses of CFOS for arbitrary finite duration input can be considered as the responses for specific initial values, so they are also same as the impulse response except complex multiple factors. (3) There is a one to one correspondance between CFOS and damped oscillating system. The system parameters of CFOS can calculated from the parameters of damped oscillating system and vice versa.
Now suppose damped oscillating waveform is obtained experimentally as the output of unknown second order system. The problem is to estimate the CFOS whose impulse response has most resemble real part to the measured waveform. Once such CFOS is determined, the system parameters of unknown second order system can be calculated. An estimation of corresponding CFOS is done by changing CFOS parameters successively to maximize the correlation between the measured waveform and the impulse response waveform of CFOS.
From the estimated parameters of second order system, the impulse response waveform can be calculated. Then the input waveform can be calculated from the measured output and the estimated impulse response. Results of computer simulation are illustrated.View full abstractDownload PDF (669K) -
Hidetoshi NONAKA, Tsutomu DATE1991 Volume 27 Issue 10 Pages 1144-1151
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe developed a video system with properties of binocular vision and motor vision, that is designed following the specification of appropriate position arrangement of cameras and CRT display.
The property of binocular vision is realized in the system by means of a pair of video cameras and a pair of liquid crystals. The directions of two cameras are set in appropriate way. Two images from video cameras-one is for right eye and the other for left eye-are displayed alternately on CRT display which viewers observe through synchronous optical shutters.
The property of motor vision is realized by means of supersonic sensors and a single dimensional camera-shifting mechanism with stepping-motor. Supersonic generating element is attached on the viewer's head and the supersonic wave from it is received by a pair of receiving elements attached on the top of CRT display. From the phase difference of two waves, the right-left motion of viewer's head is computed, which specifies the corresponding shifting of two video cameras.
We introduced the mapping from the space of real scene to the space of display image to discuss the geometric distortion of 3-D image constructed by binocular and motor properties. And we show qualitatively that the distortion is reduced, in our method, by means of appropriate position arrangement and shift mechanism of video cameras.
In our trial system, the motion of viewer is assumed to be right-left only. But the system can be extended simply for also up-down motion and forward-backward motion. In order to treat the latter motion, auto-zoom mechanism is required in cameras.View full abstractDownload PDF (1103K) -
Toru OMATA1991 Volume 27 Issue 10 Pages 1152-1158
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes an algorithm for computing the tip positions of fingers maintaining equilibrium when they grasp a polyhedral object. The author has already developed an algorithm for a planar grasp. The problem in a planar grasp is reduced to a linear programming problem using the static equivalence; the effect of changing a fingertip position along an edge is equivalent to the effect of changing the fingertip forces of the virtual fingers fixed at both ends. This equivalence makes the moment equilibrium equation in the planar grasp linear. In a spatial grasp, introducing such virtual fingers to the faces of the object decomposes the moment equilibrium equation into linear constraints and nonlinear constraints. The nonlinear constraints still remain, but they exhibit the same properties as the integer requirement in an integer programming problem. We propose an algorithm based on the branch and bound method. The algorithm decomposes each finger region until the nonlinear constraint associated with the finger is satisfied. Numerical examples show that the algorithm efficiently solves problems of practical size.View full abstractDownload PDF (887K) -
Akio YABE, Masaaki MIYAKE, Toshio EISAKA, Ryozaburo TAGAWA1991 Volume 27 Issue 10 Pages 1159-1166
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper discusses the method of a focus servo system design for a video disk player.
For a conventional focus servo system, a phase delay-lead compensation has mainly been used because we owned much know-how about it. Gain variations of each optical head have been eliminated by gain adjustment. This adjustment, however, introduces the problems, such as uneven control performance and higher cost.
We considered applying the robust model matching method, which enables us to omit the gain adjustment. This method brought in some difficulties like reconciling robust stability with low sensitivity and reducing the degree of controllers. We overcome them by using a reduced model and properly designing the model matching system and the robust filter. We also confirmed the validity of this method by experiments.View full abstractDownload PDF (1120K) -
Qiu-sheng XIE, Akira KOBAYASHI1991 Volume 27 Issue 10 Pages 1167-1174
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a construction of a pattern recognition system invariant to translation, scale-change and rotation of patterns which are included in the same similitude transformation group (STG).
In principle, an invariant system can be achieved by constructing proper normalization on patterns subject to STG and matching them with standard patterns prepared.
From the above point of view, we propose a 3-phase method for processing in feature extraction mechanism (FEM) and feature space (FS). First, normalization for translation transformation is realized through constituting FEM with Nth-order autocorrelation function of patterns (AFP). The calculations of AFP are performed with a high speed hardware based on mask pattern histogram method (MPHM) and patterns are mapped into a FS of 25 dimensions.
Second, normalization for scale-change transformation is carried out in the FS based on variance compression of mapping process from the FS into another FS.
Third, processing for rotation transformation is done by combination of establishing plural standard patterns of different rotative attitudes and utilizing the property of 90°-rotation-equivalent mask patterns.
Last, recognition process of an unknown pattern, after the pre-processing, matches it with standard patterns under a simple minimum distance criterion.
The results of experimental investigation, where 10 digit fonts and various kinds of their transformed patterns with respect to STG are employed, show that our system is useful.View full abstractDownload PDF (1034K) -
Toyomasa HATAKEYAMA, Norihiko HIROSHIMA, Hiroshi YAGI, Hideo MATUDA1991 Volume 27 Issue 10 Pages 1175-1180
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe propose a mathematical model of human thyroid gland regulating basal metabolism based on biochemical reaction in it. Parameter values appeared in the model are identified by means of the optimum parameter method. This model is taken into our previous model of a hypothalamus-anterior pituitary-thyroid system. Iodine treatment for Graves' disease can be simulated by use of the combined model.
It apparently is contradictory that the iodine keeps Graves' disease under control, nevertheless it is one of materials making the thyroid hormone. Clinical data on the interesting iodine effects could be well explained from computer simulations of this model. Other misregulations in the basal metabolism system also could be simulated by use of this model.View full abstractDownload PDF (866K) -
Jun'ichi YAMAGUCHI, Masato NAKAJIMA1991 Volume 27 Issue 10 Pages 1181-1187
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe authors have developed a compact system for finding intruders using a holographic diffraction grating which is called the Rotary Hologram Disk (RHD). The system is installed in a room on the ceiling with the surface of the RHD parallel to the floor. An IR laser beam is projected downward perpendicularly onto the RHD, and it is diffracted in two directions. The RHD rotates at a constant speed, and the diffracted beams scan the room along the two circular cones. The scanning beam light is reflected by the wall, the floor, the fixtures and the human body, and then returns to the system. By comparing the scattered light intensity with the reference data, the existence of the human bodies is detected. An example of operations of the system is described, and its merits and limitations are discussed.View full abstractDownload PDF (5015K) -
Masafumi ITO, Hisao KAWAGUCHI, Kazuhiro HANE, Fumio MATSUDA, Toshio GO ...1991 Volume 27 Issue 10 Pages 1188-1190
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA position and posture sensing technique using the light diffracted from a lithographic mark is proposed. The mark is attached to the work surface as a reference for the measurement. The rotation as well as the inclination of the work surface can be measured. The accuracies of the measurements are discussed.View full abstractDownload PDF (893K) -
Eitaku NOBUYAMA, Fernando Masami MATSUBARA, Toshiyuki KITAMORI1991 Volume 27 Issue 10 Pages 1191-1193
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with synthesis of repetitive control systems, and presents a design method for modified repetitive control systems using the partial pole assignment method in time-delay systems.View full abstractDownload PDF (364K) -
Koichi SUYAMA1991 Volume 27 Issue 10 Pages 1194-1196
Published: October 31, 1991
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a new framework for treating impartially both pure delays and distributed delays in the algebraic theory of time-delay systems, and applies it to finite spectrum assignment.View full abstractDownload PDF (328K)
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