Journal of the Visualization Society of Japan
Online ISSN : 1884-037X
Print ISSN : 0916-4731
ISSN-L : 0916-4731
Volume 21, Issue 1Supplement
Displaying 1-50 of 106 articles from this issue
  • [in Japanese]
    2001 Volume 21 Issue 1Supplement Pages 5-10
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
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  • To inspect the mystery of the speech production
    [in Japanese]
    2001 Volume 21 Issue 1Supplement Pages 11-15
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In order to solve the mystery of the speech production that talking birds and ultra-ventriloquist have acquired, their speech signals obtained in the Helium-Oxygen atmosphere were compared with those in the normal atmosphere. Furthermore, labial monosyllables /pa/ and /mo/ which the ventriloquist produced without lip movement were analyzed based on both spectral pattern and perceptual experiment. From the experimental results regarding the Helium voices, it was found that the vowel production mechanism of mynah-bird is completely different from parakeet while the parakeet and the ventriloquist produce the vowels in the same manner of normal speaker. However, the spectral pattern and the perception of /pa/ and /mo/ indicate that the ventriloquist as well as the talking birds produces those labial monosyllables in the different way of normal speaker.
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  • Kiyoshi HORII
    2001 Volume 21 Issue 1Supplement Pages 17-22
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A new methodology with linear space analysis for literary works has been developed to clarify the implicit knowledge. The implicit knowledge has contained ideas, feelings, thought processes and patterns, styles and so on without being clearly formulated and defined in the mind. For analysis of novels by Natsume Soseki, spiral styles were visualized. This spiral style was supported as common sense that Natsume wrote novels theoretically and logically by many researchers. Miyazawa's novels were observed the wave styles, which mean his novels involve rich sensitivities. The other implicit knowledge has been also disclosed; Japanese and western cultures has been clarified through style analysis of Buddhist and Christian scriptures, and the receptivity of cross-cultural values has been revealed.
    An implicit knowledge visualization through literary style analysis was based on fluid dynamical hypothesis. A hypothesis of linguistic fluid dynamics is assumed as sentences flows are linguistic fluid flow. A linguistic flow consists of four literary basic elements; sensitivity, logicality, image fluctuation in mind and multiplicity of word meaning. Sensitivity assumed as scalar potential in fluid is the motive force to put forward a logical discovery. Logical flow as vector potential in fluid is appeared with an image fluctuation caused by the change of writer's mind, leading to the multiplicity of word meaning.
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  • Shuichi KIZAWA, Shigeru MURATA
    2001 Volume 21 Issue 1Supplement Pages 23-24
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In this paper, we describes the flow visualization and the image analysis results for the thin layer flow induced by a rotating disk supported by a point-contact bearing, such as a pivot bearing. The visualization images are digitized into a personal computer to obtain velocity vectors maps using a PIV algorithm, direct cross-correlation method. The resulting velocity maps show the strong shear and unsteadiness in the thin layer.
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  • Ichiro FUJIIA, Ryota TSUBAKI
    2001 Volume 21 Issue 1Supplement Pages 25-28
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In this paper, a new image analysis method for measuring river surface flow was developed. In the presented method, some shortcomings of the large-scale-PIV, the previously developed image analysis technique by the authors, were significantly improved by using all video frames and constructing a spatiotemporal image for a searching line. Measurement of velocity in the direction of the searching line was performed by measuring an image intensity gradient of striped pattern appeared in the spatiotemporal image. By using the new method, it became possible to obtain velocity in a far field from a viewing location with a small depression angle. It was shown that the presented method demonstrates a favorable performance when applied to the actual river flow measurement.
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  • Makoto YAMAUCHI, Tomomasa UEMURA, Satoshi YAMANAKA
    2001 Volume 21 Issue 1Supplement Pages 29-30
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Bubbles are generated at a bottom nozzle and travel upward. They coalesce at a certain distance from the nozzle. Motion of the bubbles and velocity field in a vertical cylindrical liquid column are measured combining new visualization techniques and a PTV Technique. Velocity field around the bubbles changes with this chasing process quantitatively.
    The Reynolds number based on a bubble diameter is 0.2, a diameter ratio to the experimental pipe is about 0.25.
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  • Tomomasa UEMURA
    2001 Volume 21 Issue 1Supplement Pages 31-34
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    PIV techniques have been developed for one and half decades. The techniques have been applied to many kinds of fluid phenomena as its potential increases. High potential hardware such as a YAG laser, High resolution
    We have high power lasers for ideal illumination, which can be controlled to emit spatially and temporally defined light pulses, high power computers, various kinds of non-standard video cameras, and tracers. Measurement objects range from micro scale objects to actual airplanes. A velocity range expands from micron per seconds to beyond sonic velocity.
    Accelerated improvements in performances of hardware have changed PIV techniques. Applications of PIV to micron scale flows and multi-phase flows are shown in the paper.
    Some issues for further expansion of the applications are discussed in the end of the paper; Special remarks are made for the motion measurement moving objects of flexible structures.
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  • Masao SHIMIZU, Masatoshi OKUTOMI
    2001 Volume 21 Issue 1Supplement Pages 35-38
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Area-based matching is a common procedure in various fields such as fluidics, image-based measurements, and stereo image processing. Sub-pixel estimation using parabola fitting over three points with their similarity measures is also a common method to increase the resolution of matching. Some investigations or studies concerning the characteristics of this estimation have been reported.
    In this report, we applied our new algorithm reducing sub-pixel estimation error to the PIV standard images. This method is independent from the similarity measure and quite simple to implement. The results indicate the advantage of our novel method.
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  • Taketoshi OKUNO, Yasuhiko SUGII
    2001 Volume 21 Issue 1Supplement Pages 39-42
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    It is well known that PIV (Particle Imaging Velocimetry) is now firmly established as a powerful fluid dynamics tool to measure instantaneous flow velocity. This paper deals with a method for evaluation of image itself by analyzing the spatial frequency, and also for a high-speed analysis of the so-called correlation method as an application of the wavelet transform. Spatial frequency enables to evaluate the interrogation window size. The relationship between correlation function on the wavelet domain and on the normal image is clarified here. It gives a new algorithm for the PIV. The effectiveness of the present method is shown through the analysis of the Standard Image in Japan and other images.
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  • Yasufumi YAMAMOTO, Masashi NISHIDA, Tomomasa UEMURA
    2001 Volume 21 Issue 1Supplement Pages 43-44
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    The super-resolution PIV based on the successive abandonment method is developed. The successive abandonment method is accelerated by selected pixel algorithm. Error detection and displacement determination are done by summation of intensity difference distributions of neighboring templates. By these procedures, high-speed and reliable super-resolution PIV is achieved.
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  • Nao NINOMIYA, Mitsunobu AKIYAMA, Hitoshi SUGIYAMA, Akihiro KATAKAMI
    2001 Volume 21 Issue 1Supplement Pages 45-48
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Dynamic programming matching technique, which is used for the voice recognition, has been adapted to the time line images obtained by the spark tracing method for the high speed air flow. As the high voltage sparks between two electrodes trace the air flow very well, we can measure the two or three-dimensional air velocities, if we can quantify the displacement and the time interval between sparks. With the dynamic programming matching technique, the characteristics of the two consecutive spark lines are nicely corresponded and thus the three-dimensional displacement between sparks are quantified. In order to prove that the segments of the sparks are correctly corresponded, presently the radiant trail of the metal powder which is introduced into the sparks are used. As the radiant trail demonstrates the path line of the flow, it is useful to check the flow direction. Furthermore, the appropriate function for the “distance” of the DP matching is proposed.
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  • Yasuhide TAKANO, T.Goji ETOH, Kohsei TAKEHARA
    2001 Volume 21 Issue 1Supplement Pages 49-52
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In 1993, a simple questionnaire was distributed to one thousand scientists/engineers in Japan, who were potential users of high-speed imaging technologies for development of video cameras with higher frame rate. They were (1) university researchers, and (2) researchers and engineers of research institutes of central and local governments and private companies. Three thousand similar questionnaires were distributed in early 2000. In this paper, users' requirements for high-speed video cameras based on the answers of this questionnaire are presented. Based on the requirements, expected performance indices of high-speed video cameras are estimated.
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  • Haruo TERASAKA, Sensuke SHIMIZU
    2001 Volume 21 Issue 1Supplement Pages 53-54
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Very large scale computational fluid dynamics (CFD) are frequently attempted to obtain high resolution solutions or to solve large scale problems and bulky numerical data are generated. The data must be visualize to grasp and clarify precise flow characteristics. In order to reduce computer loads of the large data transfer and I/O, compression and restoration schemes are studied. In our study, the size of the original data file are compressed approximately by 1/100 by making the data thin out properly and by changing data type. The compressed data are transferred to a graphic workstation and read in a visualization software with less computer efforts. Then, they can be restored by applying an interpolation technique with allowable losses of the original fluid information.
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  • Kaoru Takizawa, Fumitake Kato, Yoshizo Okamoto, Isao Shimizu, Shinji A ...
    2001 Volume 21 Issue 1Supplement Pages 55-58
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Digital Video Recorder is widely used to visualize the dynamic image of moving body. In the field of motion science, DVR is often applied to study two and three-dimensional moving images of the human body under walking, running and jumping by means of several tracer markers on the body surface. In this study, the high-speed infrared radiometer IR simultaneously visualized the visual and thermal image of the moving human body using thermal marker and thermal footmarks. Characteristics of single- and multi-flash imaging methods were evaluated using the dynamic motion recorder.
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  • T.G. Etoh, K. Takehara, Y. Takano, T. Okinaka, Y. Kondoh, M. Maruno, K ...
    2001 Volume 21 Issue 1Supplement Pages 59-62
    Published: July 01, 2001
    Released on J-STAGE: January 22, 2010
    JOURNAL FREE ACCESS
    An high speed video camera of 1, 000, 000 fps is under development. A series of test image sensors for the camera have been designed, fabricated and tested. The sensor is an ISIS, In-situ Storage Image Sensor, which stores image signals generated on each pixel in a storage area nearby to the pixel during an image capturing phase, and release them out of the sensor during a readout phase after the image capturing. The ISIS-VU was only to test the charge transfer rate to realize the target frame rate, 1, 000, 000 fps, and some optical characteristics; the ISIS-V1 was fabricated to check the basic performance and to actually capture continuous images of 16 frames at the frame rate; the ISIS-V2 is a prototype sensor, which is mounted on a mock-up camera under development; the ISIS-V3 under basic design will be the final target sensor of the project with high performance. The development process and performances achieved so far are briefly described.
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  • [in Japanese]
    2001 Volume 21 Issue 1Supplement Pages 63-64
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Over the past several years, the infiltration of visualization techniques of human body into clinical medicine has been remarkable. In addition, the expansion of performances of 3D imaging has supplied medical diagnosis with large capabilities. Unlike usual medical imaging diagnosis, real time 3D imaging will enable the user to “visualize” rather than “read” the human structure. In addition, 4D image technology which shows dynamic changes of the human body can be generated by 3D images at high speed. With this technology, it would be possible to obtain information related to the morphology and function of the human body for new diagnosis and new treatment.
    Virtual reality technology (VR) has also been used for the handling of high dimensional (3D and 4D) medical image information. The application of this VR, technology to the field of medicine not only helped diagnosis and analysis but also brought new techniques to medical imaging.
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  • Yusuke MIYAMOTO, Takashi YAMANE, Koki TAJIMA, Eiji MOCHIZUKI, Kenji YA ...
    2001 Volume 21 Issue 1Supplement Pages 65-66
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
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  • Yasuhiko SUGII, Astushi NAKANO, Shigeru NISHIO, Motomu MINAMIYAMA
    2001 Volume 21 Issue 1Supplement Pages 67-70
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Since endothelial cells are subject to flow shear-stress, it is important to determine the fine velocity distribution in microvessels for studies of mechanical interactions between blood and endothelium. Recently, particle image velocimetry (PIV) is a quantitative method of measuring velocity fields instantaneously in experimental fluid mechanics. The authors have been developed a high-resolution PIV technique, which can improve the dynamic range, spatial resolution and measurement accuracy, and applied it to visualized images in a blood flow.
    In this paper, the proposed method is applied to visualized images in micro tube using an intravital-microscope and high-speed digital video system in order to assess measurement accuracy. The obtained velocity profile corresponds to a theoretical value. Then the micro PIV system is applied to a blood flow of straight tube in rat mesentery arterioles.
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  • Chikayoshi SUMI
    2001 Volume 21 Issue 1Supplement Pages 71-74
    Published: July 01, 2001
    Released on J-STAGE: January 22, 2010
    JOURNAL FREE ACCESS
    For various soft tissues (e.g., breast, liver, etc.), we are developing the ultrasonic strain measurement-based shear modulus reconstruction/imaging technique. To clarify the limitation of this technique as the diagnostic tool, together with improving the technique we are collecting clinical shear modulus images. Furthermore, we are applying the technique as the monitoring technique for the effectiveness of chemical therapy (e.g., anticancer drug, ethanol) and thermal therapy (e.g., rf electromagnetic wave, HIFU, etc.). Here, we showed shear modulus images obtained in quasi-real time. Using the conventional Work Station, the quantitative images were obtained on ten seconds order. In particular, by exhibiting the superiority of the shear modulus imaging compared with the simultaneous B-mode imaging, we delineated the effectiveness of the technique as the clinical visualization technique for diagnosis and therapy. For instance, shear modulus value of in vivo human breast carcinoma was significantly high (typical value : 6.33×106 N/m2). Shear modulus images were also obtained on in vivo human liver tissues. On the in vitro calf liver, shear modulus value of electromagnetic wave-induced thermal lesion became about five times higher after cooling down. We believe that this technique is currently available, and yet in the near future this technique will allow the combined diagnosis/therapy system for opening up a novel clinical style.
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  • Yasuki Nakayama, Makoto Oki, Nawoki Otonari, Katsumi Aoki, Michihito O ...
    2001 Volume 21 Issue 1Supplement Pages 75-78
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A very thin water veil like a transparent thin sheet of vinyl has been produced by shaping a double-disk nozzle in such a way to accelerate the water flow inside the nozzle. Comparison of the simulated shape of the water veil with that of the experiment shows that they are almost identical.
    Human mind can be refreshed and relaxed by being inside of this water veil. In this paper, the application of water veil to healing of mind and body is examined. The analysis of the brain wave data using the emotion spectrum analysis method (ESAM) elicited that the water veil is very useful to recover the freshness and effective to healing of mind and body.
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  • Akihiro AIHARA, Tetsuo ABE, Shoshi INOOKA
    2001 Volume 21 Issue 1Supplement Pages 79-82
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Experiments on a river flow are carried out on the basis of PTV-technique to consider the hydraulic characteristics of flows around the vegetative embayment, which is necessary for maintaining or reproducing the function of embayment as a habitat. Though the PTV-method is effective in analysis of the structure at the instantaneous of the flow field, the problem that should be solved about the accuracy still remains to get the long-time velocity information of the flow field. At first, the PTV-measurement is compared for the LDA-measurement in terms of response of particle and the particle tracking area. Next, time series of velocity is estimated from the experimental data of the PTV-measurements, which is analyzed to examine turbulence characteristics that bring about around the vegetative embayment.
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  • Kazuhide Dan
    2001 Volume 21 Issue 1Supplement Pages 83-88
    Published: July 01, 2001
    Released on J-STAGE: January 22, 2010
    JOURNAL FREE ACCESS
    When the natural light waves travel into the interface between water and air a part of the light waves refracts : and diffracts at the interface. When these waves travel to the horizontal observational plane located at the bottom of the water these waves make the light intensity in this observational plane. It is possible to calculate the wave profile by applying Suzuki-Sumines method to the brightness observed at the bottom.
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  • Tsutomu NOZAKI, Keigo IWAKUMA, Shunji MATSUMOTO, Minoru FUKUHARA
    2001 Volume 21 Issue 1Supplement Pages 89-92
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A Rotating Drum Type Solid-Liquid Separator which operates in two different modes : one is a separating mode and another a discharging one is proposed by the authors. It is necessary to discharge solid particles out of the drum which pile up on the drum wall as soon as possible. In this paper, during the discharging mode, the flow visualized experiments were carried out using a two-dimensional model, in order to clarify the effects of the discharging plates. As a result, it was found that the aspect of particles transportation changes the distance of the discharging plates and a clearance between the plate edge and the surface of the particles bed and there exists the most probable distance of plates and clearance. In the case of large distance of the discharging plates, the transportation by the scour is predominant
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  • Yuya AKAMIATSU, Noriyoshi YONEHARA, Tomomasa UEMURA, Manabu IGUCHI, Ta ...
    2001 Volume 21 Issue 1Supplement Pages 93-94
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A dissolution phenomenon of carbon dioxide into water is visualized. The authors employed solution of calcium hydroxide to detect carbon dioxide. Chemical compound (calcium carbonate) visualizes behaviors of carbon dioxide rich water. Since rate of chemical dissolution is larger than the rate of physical dissolution, it is easy to observe mass transfer phenomenon at the gas-liquid interface. High resolution video camera (1024 * 1024 pixels) and back lighting are used for observation of the interfacial phenomenon. In a top view image of the interface, the pattern exhibits a structure composed with many small cells. And also in the side view image, many slender strings slowly stretch and sink toward downward
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  • Kenji OGURA
    2001 Volume 21 Issue 1Supplement Pages 95-96
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    It is assumed that cavitation bubbles in wakes of bodies are produced in the cores of vortices formed in the wakes. An attempt to estimate the pressures in the cores of vortices formed in the wakes of circular cylinders has been made by image processing of the high-speed photographs of incipient cavitation bubbles. The vortices were taken for Rankin's vortices. The tangential velocity distributions in the vortices were measured by visualization of vortices using contour extraction and measuring rotational angle for the images of cavitation inception bubbles. It was possible to obtain the tangential velocities of cores of vortices from the peak of the tangential velocity distribution. The pressure reductions in the vortices were obtained from the tangential velocities of the cores. The pressures of the centers in the cores of vortices were obtained by subtracting the pressure reductions in the vortices from ambient wall pressures. It is satisfactory to consider that the pressure reductions by vortices bring vapor pressure or under vapor pressure in the cores of vortices at cavitation inception caused by vortices.
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  • Masahiro Inoue, Mituharu Masuda, Masato Furukawa, Takashi Muraishi, Ta ...
    2001 Volume 21 Issue 1Supplement Pages 97-100
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Feedback mechanism of self-sustained oscillation in supersonic impinging jets is studied experimentally by using a laser-induced fluorescence (LIF) technique. Phase velocities of disturbances in the flow field are obtained from a time-dependent cross-correlation function between a pressure sensor signal at a reference point and the LIF signal. A feature of disturbance propagation can be visualized by drawing maps for the cross-correlation coefficients on a plane at successive delay-times and making an animation. The discrete frequencies appeared near the neutral wave frequencies proposed by Tam and axisymmetric and helical models of the neutral wave were observed corresponding to his theory. Although the neutral waves propagate upstream both outside and inside the jet, the feedback loop is mainly accomplished by the outside propagating waves.
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  • Effect of Length of Suction Pipe
    Hidenari YAMASHITA, Minoru FUKUHARA, Tsutomu NOZAKI, Kazumi NAKAMURA, ...
    2001 Volume 21 Issue 1Supplement Pages 101-102
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    The effects of a length of suction pipe on the flow characteristics of a circular impinging jet accompanying an annular suction flow was examined experimentally at a fixed suction flow rate. The velocity field in the jet was visualized by using PIV (Particle Image Velocimetry). When the length of suction pipe increases, the flow field shows the phenomenon what the suction flow increases. And it is found that there exists the optimum size of the length of suction pipe.
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  • Shigeru MURATA, Norifumi YASUDA, Hiroshi SAKISAKA
    2001 Volume 21 Issue 1Supplement Pages 103-104
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A new digital holographic method for the detection of small particles distributed in 3D space has been developed in this paper. The method is called full volume digital holography because the light intensity of real images is computed all over the 3D region behind a hologram. The detection of particle positions is carried out by searching some local minimums or some dark regions with high contrast in the computed light intensity distribution. The performance tests are done in numerical simulation and in experiment, and the test results show that the RMS error is about 3mm for the range from 200mm to 300mm for the particle size of 100μm.
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  • Masayuki YOSHIDA, Jun SAKAKIBARA
    2001 Volume 21 Issue 1Supplement Pages 105-106
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Measurements of velocity/vorticity of cylinder wake by using stereo-PIV method.Three-dimensional vorticity iso-surfaces were successfully reconstructed from temporal series of velocity in a cross-sectional plane assuming Taylor's hypothesis. Vortex structure having a mode A pattern was observed at Re=1000.
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  • Taketoshi OKUNO, Yuki NARUSE, Shigeru NISHIO
    2001 Volume 21 Issue 1Supplement Pages 107-110
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    This paper deals with a method of PIV for the wake flow behind a ship model. In order to measure the time-averaged velocity, the statistical method is employed. It is shown that the possibility of measuring the three-dimensional velocity field by one camera and using the only one illumination sheet. In the experiment, a new tracer has been developed to use a large model, 2m long ship model in a large circulating water channel, of which the observation section has 6m long, 1.5m wide and 1.0m deep. The diameter and specific gravity of the tracer can be adjusted easily. Fairly large tracer, around 3mm diameter, is made to demonstrate its usefulness here. The measured result shows that the measurement method and the new tracer are effective for the experiments.
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  • Yuji HASHIZUME, Nobuyuki FUJISAWA
    2001 Volume 21 Issue 1Supplement Pages 111-112
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Measurement uncertainty of temperature and velocity by stereoscopic observation was evaluated using artificial color images. They were generated based on the numerical simulation data of thermal convection and with the experimental color- temperature relationship of the liquid crystals at various viewing angles of observation. The accuracy of temperature measurement was found to be improved at relatively small viewing angles between the light sheet and the camera, while that of the velocity measurement was optimized by selecting suitable combinations of PIV parameters, such as the interrogation window size, the search window size and the pixel.displacement of the images.
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  • Shigeki Maeda, Yoshiyuki Sawa, Yasuhiko Fujikawa
    2001 Volume 21 Issue 1Supplement Pages 113-116
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
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  • Yu-Cheong Im, Tetsuo Saga, Toshio Kobayashi, Takahiro Ito
    2001 Volume 21 Issue 1Supplement Pages 117-120
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    To analysis of a complex three dimensional flow structure of axial flow fan and determine the validity of its application, PIV system should be provided detailed space and time resolved experimental data for understanding and control of flow field. The high resolution stereoscopic PIV system, in this study was successfully employed at the investigation of flow structure near the axial flow fan. Using the once-per-resolution signal from the rotor, image fields were captured at a fixed poison of the blades and hence provides the ability to do phase-averaging. The three-dimensional instantaneous velocity fields and phase-averaged velocity fields, instantaneous and mean vorticity distributions and turbulent intensity of the stereoscopic PIV measurement result were represented at typical planes of the flow field. Phase-averaged velocity fields were calculated based on 200frames of the instantaneous stereoscopic PIV measurement results. From the velocity distribution, the vorticity and turbulent intensity distribution, which was known to be major factors of fan noise were calculated and its diffusion was discussed as they travel downstream. From the reconstructed three dimensional velocity iso-surface which is based on stereoscopic PIV results at 8 cross planes of the outlet flow fields, the three dimensional features can be seen clearly.
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  • Kohsei TAKEHARA, T.Goji ETOH, Tohru KUWANA
    2001 Volume 21 Issue 1Supplement Pages 121-124
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A particle mask fitting method is proposed for an accurate PTV. The particle image information, such as particle location, particle size, peak brightness, etc, is evaluated by fitting a brightness template of a particle image, which is called “Particle Mask”. The proposed particle mask fitting method is applied for a synthetic image and a captured image.
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  • Kazuo OHMI, Naohiro YOSHIDA
    2001 Volume 21 Issue 1Supplement Pages 125-128
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    The neural network technique using a self-organizing maps (SOM) model is used for the particle tracking algorithm in PIV measurement of fluid flows. The new algorithm is based on that of La Bonté [2] with further improvement for larger dynamic range of velocity and more robustness against unpaired particle images between two frames. Tests are made with typical synthetic images (PIV-STD) as well as some experimental images.
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  • Masaaki ISHIKAWA, Takehiro IDO, Atsuhide KITAGAWA, Tomoaki MATSUBARA, ...
    2001 Volume 21 Issue 1Supplement Pages 129-132
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In ordinary PTV (Particle Tracking Velocimetry), tracer particles with the good traceability have been used. However, in the field of multiphase flow, there are needs which want to analysis non-tracer particles, such as bubbles and particles with specific gravity differenced from working fluid and a large diameter. Therefore, it is necessary to discuss on the traceability of non-tracer particle. In this study, the traceability for these non-tracer particles is estimated by using Lagrangian method, which directly uses the translation momentum equation of a non-tracer particle. Also velocity vectors of working fluid for the non-tracer particle are obtained by inverse analysis, these force components acted on the non-tracer particle are shown.
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  • Takeshi SUGIMOTO
    2001 Volume 21 Issue 1Supplement Pages 133-134
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Snipes are known to exhibit peculiar display flights. They generate sounds by flattering outer tail feathers as they dive. Most snipes are almost identical. But one can tell them in the hand, because the number of tail feathers differs among species. This means the sound made by tail feathers also differs among species. This study treats Latham's Snipe Gallinago hardwickii. Measurements and analysis reveals the geometry and configuration of outer tail feathers accounts for the feature in sound spectrum of their aerial drumming.
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  • Sumiko MATSUMURA
    2001 Volume 21 Issue 1Supplement Pages 135-138
    Published: July 01, 2001
    Released on J-STAGE: January 22, 2010
    JOURNAL FREE ACCESS
    Mother-infant vocal communication and development of vocalization in several species of bats were studied under field and captive conditions. Newborn infant emit the most low frequency of attractive call. Within 2 weeks, infants gradually shift the frequency of their calls up to the ultrasonic range. Infant within 2 weeks actively does vocal exchange with returned mother from foraging. Change of vocal character in the course of development and character of time sequence of vocal exchange has been reported. In a CF (Constant Frequency) bat, Rhinolophus ferrumequinum nippon, the CF harmonics with 8kHz fundamental frequency gradually increases in frequency along the course of development. In a FM (Frequency Modulated) bat, Pipistrellus abramus, emit CF harmonics with 20kHz fundamental frequency at birth. In the course of development, CF sound with several harmonics increased downward FM steepness and shortened into the matured echolocation type signals.
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  • Tomonari AKAMATSU
    2001 Volume 21 Issue 1Supplement Pages 139-140
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Dolphins have highly developed sonar abilities and have been studied extensively in captivity. The use of sonar by dolphins and porpoises in the wild is thought to be related to the underwater navigation and searching behavior. Here we report a new and simple method to archive continuous click events individually. Echolocation click events and swimming speed of finless porpoises (Neophocaena phocaenoides) were recorded with data loggers attached on the animals. The echolocation range converted from sonar pulse intervals in open waters ranged up to 130 m. Echolocation of free-ranging dolphins appears to adapt to various distance in navigation or ranging. Silent swim distance, calculated by the swim speed multiplied by the duration of the non-echolocating periods, was smaller than the echolocation range. Finless porpoises are believed to examine their frontal area acoustically using echolocation. In other words, the observed finless porpoises swam without echolocation only in an already inspected area.
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  • Hiroyuki HIRAHARA, Masaaki KAWAHASHI
    2001 Volume 21 Issue 1Supplement Pages 141-142
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    A numerical simulation of creature's motion in a panic was executed with a kind of molecular dynamic method with intellectual particle potential function and motivation function. In the present report, a collision between two human clusters was simulated numerically..Numerical result shows that a jam was caused in the center of the collision depending on the particle density. Then, a panic in cluster was also simulated with the present method, but a panic information will be transferred by only a collision between individual particles. The travel speed of panic was slow. In the simulated process, a small confusion was caused in the center of the cluster. It was suggested from the result that an audial and visual information transfer is very important in a panic motion.
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  • Kazuma KAMISAWA, Koji KOYAMADA, Akio DOI
    2001 Volume 21 Issue 1Supplement Pages 143-144
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    In this research, it proposes a simple expression method of scalar fields using flow topology. In order to realize flow topology, to the gradient of volume data, singular points (extrema point, saddle point) is extracted and they are connected by the vector line.
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  • Issei FUJISHIRO, Shigeo TAKAHASHI, Yuriko TAKESHIMA, Rieko OTSUKA
    2001 Volume 21 Issue 1Supplement Pages 145-146
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    This article presents the concept of volume skeletonization and fleshing as a generalized process of the traditional field value-dependent transfer function (TF) design. Volume skeletonization delineates the topological structure of a given volume dataset by means of a graph called volume skeleton tree (VST), which consists of volumetric critical points and their connectivity. Both locations of critical points and their critical field values in the VST are then passed to the phase of volume fleshing to accentuate color and opacity more adaptively in the design of TFs for comprehensible volume rendering. Visually pleasing visualization results show the feasibility of the present approach as a volume data mining tool.
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  • Hiroko Nakamura, Yuriko Takeshima, Issei Fujishiro
    2001 Volume 21 Issue 1Supplement Pages 147-150
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Interval volumes allow the user to represent a three-dimensional subvolume for which associated scalar field values lie within a specified closed interval. Interval volume fitting can be viewed as a more effective tool for exploring volumetric ROIs, compared with isosurface fitting. In order to extract interval volumes from which geometrical features can be effectively mined, the coherence structure between adjacent voxels is globally examined. In addition, a simplification scheme to decimate resultant triangle patches is extended to efficiently transmit and render polygonal patch datasets for large-scale interval volumes.
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  • Web based visualization using Java
    Tsukasa TAZAWA
    2001 Volume 21 Issue 1Supplement Pages 151-154
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    An introduction of objects oriented data analysis software, S language, designed by Bell Lab., and its enhanced product, S-PLUS. Some S-PLUS add-on modules are developed for special fields, like wavelets analysis, GIS, and numerical optimization. S-PLUS Version 6, the latest version of S-PLUS, implements S-Java interface and GRAPHLETS technology. It enables to provide dynamical WEB-based application and on-line analytical processing.
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  • Koji OKAMOTO
    2001 Volume 21 Issue 1Supplement Pages 155-156
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Visual Data Mining (VDM) is the key technology of 21 century. The amount of the information is too huge to treat by individually. The Mining Technology to extract the useful information should more effective with using the Visualization technique. The combination of Information Visualization and Quantitative Visualization will be the next issue on the Visual Data Mining.
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  • Yasumasa KAJINAGA, Takayuki ITOH, Yuko IKEHATA, Jun DOI, Keisuke INOUE
    2001 Volume 21 Issue 1Supplement Pages 157-160
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Visualization techniques of various graph data, such as financial, traffic, communication, social, scientific, computer systems and the Internet, are of great need. These days, such information data rapidly grows gigantic, causing desperate needs for more efficient data manipulation and sophisticated user interfaces. To resolve these problems, several dynamics-based models have been proposed. Based upon the techniques developed to tackle with huge graph data, we report the results of the web-site visualization of several sites. With these results, we consider the effectiveness of this application to the other known visualization techniques.
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  • Kazuyuki Hirasawa, Yoshihito Kikkawa, Hideo Miyachi, Akira Ukawa, Tais ...
    2001 Volume 21 Issue 1Supplement Pages 161-162
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    To visualize large data at high speed, parallelization is required. We developed parallelized volume rendering module in the visualization software AVS/Express. In general, it is not easy to change existing source codes. In this paper, the volume rendering module is parallelized in three ways : auto-parallelization, OpenMP and pthread. We compare these methods in parallelized performance and difficulty of the coding.
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  • Yuko OSHIMA, Toshiyuki TAKAMIYA
    2001 Volume 21 Issue 1Supplement Pages 163-166
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Rotating vane type flow meter has been widely used to measure the tap water quantity to each household through water supply network. This device consists of vane rotor and is set across the water piping. The rotor rotation is supposed to be proportional to the total flow quantity. Since this is a measuring device, it must be reliably accurate for defined usage condition, which is usually very strict and wide. In order to design such device, knowledge on the flow condition in them is essential, and since the flow conditions are very complicated, theoretical or computational fluid dynamic analyses are hardly competent. Here we used Hydrogen Bubble Flow Visualization technique, and obtained complete understanding of the flow character in such device.
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  • Shinzaburo UMEDA, Wen-Jei YANG, Masaaki SHIONO, Akira TANIGUCHI
    2001 Volume 21 Issue 1Supplement Pages 167-170
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Research results pertinent to heat exchangers are available in existing literature and heat transfer text books. However, it was short of sufficient flow visualizations in louver fins because of the difficulty in its flow visualization. Flow visualization by means of the dye injection method and the laser Doppler velocimetry (LDV) was performed to disclose flow characteristics in louver fins. Fin pitches Pf and louver angles θ in louver fins were varied. Flow patterns in each louver fins are visualized using the fluorescein dye illuminated a laser light sheet. The LDV data were used to calculate Reynolds stress distributions and power spectrum distributions. It is disclosed that vortices in cases of θ=15° and 20° for Pf =100mm exhibit a distinctive periodic characteristics, and the Strouhal number is uniquely related to the Reynolds number.
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  • Keisuke KUBOTA, Atsuyoshi INOUE, Yasuaki SHIINA, Terumi INAGAKI
    2001 Volume 21 Issue 1Supplement Pages 171-174
    Published: July 01, 2001
    Released on J-STAGE: September 03, 2009
    JOURNAL FREE ACCESS
    Effect of metal wire immersed in cylindrical capsules on melting of solid phase by forced convection was studied by flow visualization technique. Experiment was compared with numerical analysis. Melting time agreed with the numerical results obtained by the use of non-uniform heat transfer coefficient on the capsule surface of small diameter. Metal wire decreases the surface temperature of the capsules and suppresses natural convection in the capsules. Finally, increase in effective thermal conductivity due to metal wire reduces melting time of the phase change fluid. The shape of the solid liquid boundary became more concentric by inserting the metal wire.
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