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Volume 37, Issue 7
Displaying 1-13 of 13 articles from this issue
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Tatsuya HARADA, Akiko SAKATA, Yutaka IIDA, Taketoshi MORI, Tomomasa SA ...2001 Volume 37 Issue 7 Pages 593-601
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a system of a pillow to measure human physiological parameters in sleep without restraint to the human. The system consists of an ordinary pillow, an array of pressure sensors under the pillow, a one-chip microcomputer to digitize and transmit the pressure data to a desktop computer and the computer to count respiration and turn in sleep. This paper also presents a simple motion model, which explains the difference of the pressure distribution at a head position accompanied with respiration. Based on this model, robust respiration measuring algorithm is proposed. The respiration and body movement measuring possibility of the system is experimentally shown by comparing respiration and turn in sleep measured by the system and those measured by a medical respiration monitoring device and a video respectively.View full abstractDownload PDF (3884K) -
Hitoshi KAMETANI2001 Volume 37 Issue 7 Pages 602-608
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSOptical computed tomography, optical CT, is the medical imaging modality in which near-infrared light is used to probe biological tissues. To investigate the inside of a highly scattering medium like biological tissue, we have developed the optical CT system which can measure an intensity distribution of light pulses transmitting through highly scattering medium by using the photon counting method. Intensity distributions of transmitted light pulses were measured by changing a concentration of Intralipid-10%, a highly scattering medium, in salt solution. This experiment makes it clear that the FWHM of the intensity distribution increases gradually and a peak existing in the distribution begins to lack with the increase of the concentration of Intralipid-10%. To reconstruct an image of an object, a peak channel and a weighted integral value of the intensity distribution of the transmitted light pulse were used as a projection data in this optical CT system. For instance, an optical CT image of an absorber in salt solution with 1.3% Intralipid-10% was reconstructed from the projection data taken by this method, so the comparatively good experimental result was obtained. Furthermore, image reconstructions of a gumbo and a boiled egg of a quail were performed using the projection data by our method. As a result, we could reconstruct five species in the gumbo and detect that the yolk inclines in the boiled egg.View full abstractDownload PDF (4091K) -
Masahiro ISHIBASHI, Masaki TAKAMOTO2001 Volume 37 Issue 7 Pages 609-617
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSFlow velocities from several m/s to supersonic of a gas having a Prandtl number different from unity were measured based on the recovery temperatures measurement using a very thin thermocouple, which produced almost no disturbance in the field. Very high space resolution in the 10μm order as well as very small disturbance from the supports of the thermocouple wire were achieved because the sensing point of a themocouple wire was concentrated exactly at the contact point, which allows to use a long thermocouple wire to locate its supports far away from the measuring point.
A thermocouple wire of 50μmφ accompanied with a traversing system was settled through an axi-symmetrical critical nozzle with a throat diameter of 13.4mmφ to measure the velocity field in the nozzle. The results agreed quite well with the one-dimensional isentropic theory even qualitatively as well as they showed the fine structure predicted by the two-dimensional isentropic theory. Furthermore, the results revealed complicated flow structures, which were unpredictable by these simple theories, such as oblique shocks and normal shock whose amplitude and location changed depending on the back pressure ratio applied on the nozzle in a complicated manner.View full abstractDownload PDF (4431K) -
Guido IZUTA, Keiji WATANABE, Zhi WEI LUO2001 Volume 37 Issue 7 Pages 618-625
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a practical design methodology for multivariable systems with output delays to satisfy the mixed sensitivity specifications. The controller parametrization is developed on the basis of the state space approach to apply to unstable multivariable systems with output delays. The controller is realized as the generalized stabilizer with predictor.View full abstractDownload PDF (1408K) -
Kenji OTSUKA, Kiyotaka SHIMIZU2001 Volume 37 Issue 7 Pages 626-632
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper is concerned with the Direct Gradient Descent Control (DGDC), which produces a dynamic state feedback control for stabilizing general nonlinear systems. DGDC manipulates control inputs directly so as to decrease a performance function like the squared error, based on the gradients of the performance function and the steepest descent method. Stability of DGDC is proved by use of the comparison function method. We also prove that if linearlized system of DGDC has a minimum phase property, then a proportional coefficient for the steepest descent method exists such that DGDC achieves asymptotical stability. Based on this result a design method of asymptotically stable DGDC is proposed. The effectiveness of the proposed method is confirmed with simulation result for various nonlinear plant.View full abstractDownload PDF (1348K) -
Fumitoshi MATSUNO, Takashi OHNO2001 Volume 37 Issue 7 Pages 633-639
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we discuss a simple controller for a large space structure with distributed and lumped flexibility based on a distributed parameter model. As a typical example of large space structures, we consider two flexible beams connected by a spring. The flexible beam and the spring can be regarded as an element of the structure with the distributed flexibility and a connective part with uncertain lumped flexibility, respectively. We propose a sensor output feedback controller for vibration absorption. Using the Energy Multiplier method, we prove the exponential stability of the closed-loop system. As we introduce voigt type damping, the open-loop system is exponential stable. If the damping coefficient is small, we prove that the exponential convergence rate for the closed-loop system, that means performance of controllers, is larger than that of the open-loop system. As we do not need an approximated finite-dimensional model at the controller design phase, the controller based on the original distributed parameter system is robust and simple.View full abstractDownload PDF (1513K) -
Qiubao ZHENG, Hidenori KIMURA2001 Volume 37 Issue 7 Pages 640-646
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a variant of k Bipartite Neighbors (k-BN), called k-BN2, for function prediction. Like k-BN, k-BN2 selects k instances surrounding a query, i.e., a novel instance, and keeps them bipartitely. However, in order to improve the prediction precision, based on the bipartite neighborhoods, k-BN2 combines local linear models and global nonlinear model to predict the value of the novel instance. Applied to two real measured datasets, k-BN2 outperforms typical k-BN and those methods in which k-BN or related approximate physical model alone is used.View full abstractDownload PDF (2203K) -
Yingjie YIN, Kazuya OGATA, Yoshikazu HAYAKAWA2001 Volume 37 Issue 7 Pages 647-656
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSWe consider the trajectory tracking problem for robot manipulators with unknown parameters, which are subject to bounded disturbances belong to L2. We provide a state feedback adaptive robust control algorithm which guarantees arbitrary transient performance as well as arbitrary disturbance attenuation. If the disturbances vanish and the trajectory hold on a constant position, the proposed controller achieves asymptotic tracking. Instead of estimate all unknown parameters as in other methods until now, we estimate the unknown parameters only in gravitational forces vector, lead the controller to a simple one.View full abstractDownload PDF (2096K) -
Naohiro KUSUMI, Kotaro HIRASAWA, Jinglu HU, Junichi MURATA2001 Volume 37 Issue 7 Pages 657-664
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, many people are involved in the research of complex systems which are made of a large number of elements interacting with each other.
In this paper, a new modeling method of mutual interaction of the complicated systems is proposed by using Spatial Distribution Universal Learning Networks (SdULNs) and Fuzzy inference algorithms.
In addition, the proposed model is applied to the modeling of ecosystems which are described as the Lotka-Volterra equation.
From simulations where apriori information on ecosystems is given, it has been cleared that the proposed method can present more flexible emergent dynamics than the conventional Lotka-Volterra equation.View full abstractDownload PDF (1915K) -
Yasuaki KUROE, Yoshihiko YOSHIZAKI, Hajimu KAWAKAMI, Takehiro MORI2001 Volume 37 Issue 7 Pages 665-674
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we present a versatile method of solving the problem of shape from shading in computer vision by neural networks. The proposed method is versatile in the following sense. (i) It can deal with all the surface-reflection models which have been proposed so far. (ii) It can handle the case where not only a single image of an object but also a few or more images taken by different illumination and shooting conditions are available for surface recovering. (iii) It can handle the case where not only image data but also depth and/or gradient data of an object taken by appropriate sensors are available.
We first introduce a mathematical model, which we call ‘image-formation model’, expressing the process that the image is formed from an object in some illumination and shooting condition. We formulate the problem of surface recovery into the learning problem of neural networks with inclusion of the image-formation model in the learning loop and derive its learning algorithm. The proposed method can be used to solve various problems in all the above situations by changing the image-formation model according to the situations.View full abstractDownload PDF (5086K) -
Toyonaka HIRAI, Yoshifumi KITAYAMA, Takao TAKAGI, Hiroshi MORIYASU2001 Volume 37 Issue 7 Pages 675-680
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSRecently, the speed of image processing has been increased owing to the outstanding advance in CPU capability and various techniques in image measurement have been proposed. In most of these techniques, size and absolute coordinate of any object are obtained from the image taken by CCD camera with the resolution into account. As human being recognizes the object in the scene through experience and background, its size and coordinate do not necessarily coincide with those acquired through traditional image algorithms. Accordingly, in measuring the perceptual characteristic of esthetic phenomena from the image and perceptibly recognizing the scene, it is needed not to evaluate qualitatively but to formulate it so as to be able to use as an application. We then aimed at illusion figure well known in experimental psychology, formulated the illusion magnitude of the figure, and applied to test-line information of real image. As a result, we could get a fairly good result.View full abstractDownload PDF (2204K) -
Takashi SHIMA2001 Volume 37 Issue 7 Pages 681-683
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, new structures of Chebyshev polynomial based network and Legendre polynomial based network are proposed and applied to the optimal control problems as the feedback controllers. It is shown that good results are obtained.View full abstractDownload PDF (462K) -
Shuji ITO, Shinji HARA, Kohei MORI2001 Volume 37 Issue 7 Pages 684-686
Published: July 31, 2001
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSSolving bilinear matrix inequality (BMI) problems appearing in robust control by deterministic strategy is quite hard. We propose a branch and bound method for BMI optimization problems where a randomized algorithm is used in the bounding procedure. Computational experiments demonstrate the effectiveness of the proposed method.View full abstractDownload PDF (545K)
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