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Koichi ICHIMIYA, Mikio IIZUKA, Tatsuya SUZUKI
2004 Volume 24 Issue Supplement1 Pages
323-326
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper describes the flow visualization of particles in a cylindrical vessel for dry using PIV. The working fluid is air. The particles of foaming styrene and plastic beads were applied as tracers. Experiments were carried out for various Reynolds number and three positions of a nozzle. Results show that flow is composed of the impingement on the side wall, small recirculating flow and swirl-rising flow. Effects of the nozzle positions affect the impingement position on the wall.
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Shingo KISHIKAWA, Hiroshige KIKURA, Hideki KAWAI, Hiroshi TAKAHASHI, M ...
2004 Volume 24 Issue Supplement1 Pages
327-330
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In this study, experiment was carried out for Taylor-couette voltex flow between a rotating inner cylinder and a fixed outer cylinder with small aspect ratio. It is two concentric rotating cylinders with a 25mm gap in aspect ration 3 and radial ratio 0.667 by mean of an ultrasonic velocity profiler (UVP). Successive instantaneous and mean velocity profiles were obtained by an ultrasonic Doppler velocity profile method, and the spatiotemporal velocity field had been analyzed by two-dimensional Fourier transform in following the transition region of the turbulent flows MVF and WVF of three cell mode, N-2Cell, N-4Cell and A-3Cell mode.
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Takashi MIKAMI, Masaru ISHIZUKA, Shinji NAKAGAWA, Koichiro KAWANO, Yos ...
2004 Volume 24 Issue Supplement1 Pages
331-332
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A water exchange process in a biosensor container was visualized using a laser fluorescence technique and measured using a PIV. The water exchange process needs optimizing in order to shorten the start up period and not to break lipid membrane. The time and volume needed for the completion of the water exchange process was obtained. The effect of flow rate on the completion volume and fluid motion was discussed.
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Hironobu UEKI, Daisaku SAKAGUCHI, Masahiro ISHIDA, Keisuke NAKAHARA
2004 Volume 24 Issue Supplement1 Pages
333-334
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In order to measure the disintegration phenomena of diesel fuel droplet by a compact PIV optical system with variable lighting duration, 15 red super bright LEDs and 15 yellow ones were used for a light source. More electric currents than ten times of the standard were supplied to each LED for increasing the light intensity. A CCD camera was used to record images of glass beads of 30, 60, and 100μm in diameter mixed in the air jet stream. It is clearly shown that the luminosity integration value of a particle image is proportional to the 2nd power of particle diameter. Two images corresponding to two kinds of LED were extracted from the double exposure image of fuel droplets injected in the atmosphere from the diesel fuel injection nozzle. It is clarified that inner droplets is larger than outer droplets in the spray periphery region.
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Yuki Nakamura, Nobuyuki Fujisawa, Koichi Nakamura
2004 Volume 24 Issue Supplement1 Pages
335-336
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The evaluation method of pressure distribution using the velocity field measured by micro PIV is studied in a straight micro-channel flow with square cross section. In this method, the three-dimensional velocity field is assumed parabolic except for the experimental cross-sectional velocity distribution measured by micro PIV The comparison between the evaluated pressure drop and the numerical result by Navier-Stokes equation indicates good agreement with each other, which suggests the validity of this method for evaluate the pressure drop in the micro channel.
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Tomonori Nakano, Nobuyuki Fujisawa
2004 Volume 24 Issue Supplement1 Pages
337-340
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The tonal noise source and the corresponding instantaneous velocity field around an aerofoil NACA0018 are measured to understand the mechanism of aerodynamic noise. The source measurement indicates that the tonal noise is generated from the rear side of pressure surface of the aerofoil. The simultaneous measurement of velocity field by PIV in reference to the sound pressure signal shows that highly correlated patterns of vortex shedding with respect to the sound pressures are generated from the trailing edge of the aerofoil. Therefore, the tonal noise could be generated by the periodic formation and shedding process of vortices from the trailing edge of pressure surface.
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Masaya KIUCHI, Nobuyuki FUJISAWA
2004 Volume 24 Issue Supplement1 Pages
341-344
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper reports the measurement of three-dimensional velocity field in a spray combustion chamber with and without combustion using a combined use of planar PIV technique and with a rotary shutter mechanism. An uncertainty analysis has been carried out using artificial images, which include the influence of luminous noise generated by the spray combustion. The present results indicate that the flow pattern inside the combustion chamber is modified to strengthen the vertical flow motion relative to the horizontal one under the influence of combustion.
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Masaaki ISHIKAWA, Koji OKAMOTO, Haruki MADARAME
2004 Volume 24 Issue Supplement1 Pages
345-348
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The Dynamic PIV system (Time-resolved PIV) has been applied to the high-speed mist flow with edge obstacle in a narrow channel. The boundary layer has been clearly visualized with the high-speed camera and high repetition double-pulse laser. The target area is 10mm with 10m/s, i.e. Re=10, 000. The top side and bottom side edge flow are captured to evaluate the detail flow structure of the boundary layer.
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[in Japanese], [in Japanese], [in Japanese]
2004 Volume 24 Issue Supplement1 Pages
349-352
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper compares the accuracy of the novel PIV technique based on the optical flow concept and the conventional PIV with the Gaussian sub-pixel fitting. In the new technique, we take into account of image gradient terms with three consecutive frames in the optical flow treatment in order to improve the accuracy for complex flows. This paper includes: i) the fundamental concept and formula of the new method, ii) experiments with standard PIV images, video sequences of the meandering channel flow in a Japanese old garden and flow images of the Uji river, and iii) the discussion on the measurement accuracy. The result shows that the presented method is superior to the conventional PIV especially in the measurement of instantaneous flow field with rotational motion.
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Masao Sumiya, Yoshizo Okamoto, Masahiro Agu, Kaoru Takizawa, Ken Yamaz ...
2004 Volume 24 Issue Supplement1 Pages
353-356
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A visual digital recorder system (DVR) is widely used to visualize and analyze the dynamic image of moving body. The simultaneous instrumentation system of the DVR and infrared radiometer (IR) was applied to study two and three-dimensional moving images of the human body under walking, running and jumping.
Dynamic behaviors of human body segments are numerically obtained and analyzed by using the personal computer. Characteristics of single-and multi-flash imaging methods of the human body were evaluated using the dynamic motion recorder. Lastly, a fluctuation performance of the moving human body was calculated quantitatively.
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Symmetry of leading edge vortex on a plate wing during heaving motion
Daisuke KONDO, Tsutomu TAJIKAWA, Atsushi SAKURAI, Kenkichi OHBA
2004 Volume 24 Issue Supplement1 Pages
357-358
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The purpose of this study is to investigate flow pattern around mosquito's wing while it is beating. We constructed on experimental apparatus to simulate beating motion of mosquito. An enlarged scale model experiment was carried out using a very low speed wind tunnel under the condition that Reynolds number and Strouhal number were made equal to those of real mosquito. The flow around the wing model moving up and down was visualized using smoke and laser light sheet and it was analyzed by a PIV system. Unsteady vortices were observed to be generated on the upper surface of the model wing in the period of downstroke. We compared the vortices each other on three different kinds of enlarged scale models (8, 10, 12.5 times). As a result of Reynolds number and Strohal number are corresponded and attached wing symmetry, the flow around the wing corresponded indeoendently of the enlarged scale.
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Masaki FUCHIWAKI, Kazuhiro TANAKA
2004 Volume 24 Issue Supplement1 Pages
359-362
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Many studies on unsteady flow behind an unsteady airfoil have been carried out with experimental and numerical approaches. However, the detailed wake structure has not been understood sufficiently. In order to clarify the qualitative and quantitative wake structure behind unsteady airfoils, such as pitching airfoil and heaving airfoil, at low Reynolds number region, we have carried out the flow visualization and particle image velocimetry measurement at Re = 4000. The thrust producing vortex street is formed behind pitching airfoil with high non-dimensional trailing edge velocity and heaving airfoil with high non-dimensional heaving velocity, and the qualitative wake structure in both airfoils is the same. However, the quantitative wake structure in both airfoils is not same. The vorticity in the thrust producing vortex street of heaving airfoil is higher than that of pitching airfoil. As a result, velocity profile in the wake of heaving airfoil is larger than that of pitching airfoil.
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Hiroshi NAKAYAMA, Masafumi HIROTA, Kazuhiro SHINODA
2004 Volume 24 Issue Supplement1 Pages
363-366
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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We investigated experimentally the unsteady flow in a counter-type T-junction. The T-junction was modeled by a mixing tee with square cross sections, in which the mixing channel was connected with the main and counter channels at right angles. Detailed distribution of velocity data have been measured using PIV. Reynolds number of the main-channel flow was fixed at 3500, and the velocity ratio of the counter-channel flow to main one was changed from 1.0 to 5.0. To identify the coherent flow structures, the proper orthogonal decomposition (POD) analysis was applied to the fluctuating velocity field in the mixing channel. Based on the data, the unsteady vortical motion along the shear layer and the wobbling motion of the interface between the main-channel and counter-channel flows are. discussed.
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Katsuya NAGAYANA, Fumio SHIMIZU, Hiroshi HIGO, Kazuhiro TANAKA
2004 Volume 24 Issue Supplement1 Pages
367-368
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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3 dimensional vortex structure around free falling rectangular pillar was studied in comparison with circular cylinder. Both objects are close to square shape in front view but flow fields measured by PIV method were different. Vortex pair starting from the upper corner was stretched to upper direction in case of rectangular pillar, while it was observed at upper surface in case of circular cylinder. On the upper surface of rectangular pillar, water flows out in front view, while in side view water flows in.
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Hiroaki KAWAI, Hideo Ohtake, Akiyoshi TAIRA
2004 Volume 24 Issue Supplement1 Pages
369-372
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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An experimental study was performed to observe the heat transfer characteristics of the natural convection from a vertical row of heated horizontal cylinders placed in a cavity. The gap between the vertical wall of the cavity and cylinder surface was varied from 0mm to infinity. Experiments were carried out under the condition of uniform heat flux for each cylinder. As results of a present investigation, it was observed that an increase in heat flux causes the increase in heat transfer coefficient. It was also found that optimum value of the gap which provides a maximum heat transfer coefficient was existed. It becomes very important for designing heating devices.
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Koichi ICHIMIYA, Koji TORIYAMA, Hisahiro WATANABE
2004 Volume 24 Issue Supplement1 Pages
373-376
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper describes the flow visualization of the three-dimensional mixed convection in a horizontal square channel with heated and cooled side walls by dye-injection method. The working fluid is water. The water temperature at inlet is changed from 10°C to 50°C. Three-dimensional spiral flows are observed along the longitudinal direction of the channel. In the case of 50°C inlet temperature, a pair of spiral flows, clockwise and counter clockwise rotation, are generated across a section. The pitch of the spiral flow decreases with increase of Richardson number Ri(??Gr/Re
2 ).
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Hidemi YAMADA
2004 Volume 24 Issue Supplement1 Pages
377-378
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Flow pattern of the necklace vortices in the gap space between two circular cylinders whose diameter is different forming a separated cross was visualized in the symmetrical plane under the Reynolds number of 1500. The space ratio was altered from s/d
1=0 to 2.0, and the diameter ratio was altered from d
2/d
1=0.67 to 1.5. As the results, 8-system of necklace vortices is formed in the wide range of s/d
1 and d
2/d
1. The space ratio in which the necklace vortex is formed becomes large with the diameter ratio increasing.
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using Ruthenium(II)complex
Hirofumi Ouchi, Nobuyoshi Fujimatu, Kozo Fujii, Tomoko Irikado, Kiyosh ...
2004 Volume 24 Issue Supplement1 Pages
379-382
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Surface pressure of a complicated space shuttle type model has been measured by using the pressure sensitive paint (PSP) in the ISAS/JAXA transonic large-scale wind tunnel. A new automatic marker detection method is has been developed so that all markers on the model are accurately detected for efficient the image registration. Enough number of the markers was successfully detected to estimate the model displacement during wind-on accurately. As a result, surface pressure distribution over the model was successfully obtained by the PSP measurement. Also, coordinates of the model surface are measured by the equipment of the configuration measurement for measured surface pressure mapping so that aerodynamic forces obtained by the mapped surface pressure can be compared with the balance measurement data.
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Yoshimi IIJIMA, Hirotaka SAKAUE, Yasuhiro EGAMI, Akira NISHIZAWA, Keis ...
2004 Volume 24 Issue Supplement1 Pages
383-386
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A new Temperature-Sensitive Paint (TSP) technique for boundary-layer transition detection in a production-type large cryogenic wind tunnel is present. The formulation of Ruthenium complex TSP system has been optimized in terms of luminescence intensity and robustness. The optimum dye-binder-solvent combination has been determined through systematic sample tests. A new binder has been introduced and the resulting coating was found free from cracking at cryogenic temperatures. This is contrary to the silicone-based cryogenic TSPs that are subject to micro cracks at reduced temperatures. The new TSP can meet the root-mean-square roughness requirement less than 0.15 ?m. We applied this TSP in the JAXA 0.1-m Transonic Cryogenic Wind Tunnel, and then European Transonic Windtunnel (ETW). A variety of transition patterns have been successfully visualized.
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Masahiro KITAMURA, Yoshitaka SAKAMURA, Tateyuki SUZUKI
2004 Volume 24 Issue Supplement1 Pages
387-388
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The objective of the present work is to study the feasibility of the pressure-sensitive paint (PSP) technique for pressure measurements on rotating objects. The PSP used was composed of a porphyrin derivative (H
2TFPP) and a silica-gel thin-layer chromatography plate. The illumination sources were arrays of blue LED, and the detecter was a CCD camera with 12 bit intensity resolution. In the experiments, the shutter of the CCD camera was left open and a rotating model was flashed repeatedly as it came into position, building up a phase-averaged image on the CCD camera. The present preliminary experiments show that the deformation of the model under air loads seriously affects the PSP measurements on rotating bodies.
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Nobuyoshi FUJIMATSU, Isao MISU
2004 Volume 24 Issue Supplement1 Pages
389-390
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Image processing procedure to automatically carry out the image registration in the PSP experiments is investigated. A few algorithms to detect the object boundary are used and tested. The object boundary can be successfully captured using these algorithms. The pattern recognition based on the distance of function is used for the decision of the points of feature for the image registration. The method can correctly find a pair of these points. The results indicate that the image registration can be automated using the method developed in this paper.
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Hiroshi Iwata, Yoshimune Nagao, Hiromitsu Kawazoe
2004 Volume 24 Issue Supplement1 Pages
391-394
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This study was conducted for an aerospike nozzle and to analyze the phenomena of the jet impingement, which was spout out from a circular nozzle with four or eight holes to a flat plate. The impingment was undertaken to be perpendicular and oblique to the plate. If the distance between the flat plate and the nozzle becomes close, an usual PSP analysis is difficult because the source of light, a camera and the nozzle can not be set up for the PSP measurements. Therefore, the pressure on the plate was observed from the back side of the a flat plate. Furthermore, the visualization of the impingement jet flow was studied by the oil film method.
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Hideo MORI, Tomohide NIIMI, Yusuke OSHIMA, Madoka HIRAKO, Hiroyuki UEN ...
2004 Volume 24 Issue Supplement1 Pages
395-398
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The pressure sensitive paint (PSP) technique has the capability to be applied to high Knudsen number flows, such as low density gas flows, micro-flows, etc. In this study, to inspect the feasibility of PSP for measurement of pressure on a solid surface in the high Knudsen number flows, fundamental properties of three types of PSP [PdTFPP, PdOEP and PtTFPP bound by poly(TMSP)] are examined especially in the range of pressure below 133.3Pa(1Torr). The pressure sensitivities against nitrogen oxide are also examined for the above PSPs, to develop a technique for the simultaneous measurement of the flow field structure and the surface pressure, using NO-LIF and PSP, respectively. As an application of PSP to low density gas flows, we measure the pressure distribution on a jet-impinging solid surface using PdOEP with extreamly high pressure sensitivity.
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Shinkichi ABE, Haruki MADARAME, Koji OKAMOTO
2004 Volume 24 Issue Supplement1 Pages
399-402
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A method for visualizing the spatial distribution of oxygen using particles coated with pressure-sensitive dye is presented. The proposed technique is a hybrid system combining the technologies of pressure-sensitive paint (PSP) and particle image velocimetry (PIV). It allows the particle velocity and oxygen distribution to be measured simultaneously. As intensity-based imaging is not applicable in this system, a luminescence lifetime-based imaging technique involving double frame imaging is introduced. The system is calibrated and demonstrated in application to an air jet, showing the simultaneous measurement to be effective.
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Kazunori MITSUO, Keisuke ASAI, Akira TAKAHASHI, Hiroshi MIZUSHIMA
2004 Volume 24 Issue Supplement1 Pages
403-406
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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We have developed a lifetime imaging system to simultaneously measure pressure and temperature image from a luminescent decay of pressure-sensitive paint (PSP). Analysis of PtTFPP-PSP by a streak camera showed the dependence of luminescent lifetime decays on pressure and temperature. We have built a lifetime imaging system (LIS) composed of a pulsed laser and an ICCD camera. The three gated times of a CCD camera were determined referring to the streak camera data. The performance of this system was evaluated over the wide range of pressure and temperature using a PSP coupon as a test article. As a result, the ratios of the gated images could be fitted with a smooth function of pressure and temperature. This allowed us to reconstruct pressure and temperature from three luminescent lifetime images. Furthermore, as a verification test, pressure and temperature map induced by a sonic-jet impingement flow were visualized. PSP data agreed with pressure tap data, indicating that this lifetime imaging system allowed us to measure pressure and temperature field.
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Kazutoshi Shindo
2004 Volume 24 Issue Supplement1 Pages
407-410
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The EchoScope Real Time 3D sonar generates instantaneous 3D images. Every 3D data set is the result of a single acoustic transmitter pulse, hence movement of the sonar head does not distort the data. All data points based on the same transmitter pulse are consistent. An acoustic volume is insonified by the transmitter pulse and the echoes are detected by using a 2D array of 1600 hydrophones. Phase and amplitude are used for parallel generation of 4096 receiver beams (New version: 16384) and 2D lateral images are generated in range slices.
The resulting 3D data set contains intensity as well as 3D co-ordinates (x, y and z). These co-ordinates are automatically georeferenced through a GPS receiver and a heading sensor. The Echoscope is also equipped with a roll & pitch sensor.
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Kazuo Hitomi, Hiroshi Yamanouchi, Noboru Taguchi, [in Japanese], [in J ...
2004 Volume 24 Issue Supplement1 Pages
411-414
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper describes remote sensing to detect the sunken ship and oil in bottom of the sea using 3D-imaging scanner, multi-beam sonar, Fluorescence LIDAR.
The performance was confirmed by a basic experiment, the field experiment and shipboard experiment.
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Masahiko SASANO, Kazuo HITOMI, Hiroshi YAMANOUCHI, Noboru TAGUCHI, Sus ...
2004 Volume 24 Issue Supplement1 Pages
415-416
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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A tanker accident has a possibility for enormous pollution of coastal environment arising from substantial volume of oil spill. It is desirable to clean up oil spill on the ocean by the oil recovery vessel, or spray oil dispersant immediately after the accident. For these processes, the airborne lidar system is a powerful tool to collect oil spill information in real time.
We have developed a helicopter-based fluorescence lidar system for oil spill detection, which also be used as a passive sensor for detection of oil spill in daytime. This system basically consists of a 355nm UV pulse laser. and a four wavelength simultaneous detect ICCD camera to visualize laser induced fluorescence light from oil spill.
In this paper, the system specifications and its preliminary results are shown.
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Munehiko HINATSU, Yoshiaki TSUKADA, Hiroshi TOMITA, Akira HARASHIMA
2004 Volume 24 Issue Supplement1 Pages
417-420
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Recently monitoring of sea healthiness using voluntary observation ships has been carried out. In the monitoring, seawater is sampled through an inlet located on a ship hull, and the water is analyzed chemically and biologically. In the coarse of analyses, the information of original position of sampled water is one of important factors to assess the sea healthiness, and in the paper, an empirical method to estimate the original location of sampled water is described.
In the experiment, dye is injected from the upstream of the ship. The water around ship is picked up from the inlet, and then dye concentration in the sampled water is analyzed using a spectrophotometer. The concentration is mapped onto the plane of dye injection and we thus show the original location of sampled water as a contour map on the upstream sectional plane.
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Chang-Kyu RHEEM
2004 Volume 24 Issue Supplement1 Pages
421-422
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Active microwave remote sensing is a powerful technique for a sea surface measurement. A basic principle of the sea surface measurement by active microwave remote sensing is to be difference in microwave backscatter from sea surface by the sea surface conditions. Some physical values of sea surface, such as wind, waves and currents can be obtained by analyzing of microwave backscatter from sea surface. In order to develop more advanced remote sensing technique of sea surface, it is necessary to understand the mechanism of microwave at sea surface in detail. This paper describes the characteristics of microwave backscatter from water surface and the relation between the physical values of water surface and microwave backscattering at that surface.
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Shotaro UTO, Haruhito SHIMODA, Koh IZUMIYAMA, Kazutaka TATEYAMA, Shuki ...
2004 Volume 24 Issue Supplement1 Pages
423-426
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Sea ice thickness is one of the most important geophysical parameters for understanding formation and variability of the global climate system. It is also important from the engineering point of view, because it is one of the most dominant parameters which influence on the ice load exerted on ships and structures. However limited data is available at present. The authors have conducted the observations of sea ice thickness onboard Antarctic research vessel "Shirase" and patrol vessel "Soya" using the electromagnetic-inductive (EM) method. The principle for observing sea ice thickness by the EM method was described in detail. The authors reported the distributions of the sea ice thickness of the land-fast ice in Lutzow-Holm bay, Antarctica and the pack ice in the Sea of Okhotsk.
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Taketoshi OKUNO, Nozomu TANIMOTO, Naoki NAKATANI
2004 Volume 24 Issue Supplement1 Pages
427-430
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In order to clarify the flow structure generated by Oloid wing, which is constructed by two circular disks, the flow velocity field is visualized and also is measured by a small velocimetry, a conventional propeller type one. In the previous two reports, it was found that the vortex ring can travel far away and it would be effective for mixing phenomenon. This paper deals with the measured flow rate, the entrainment rate, mixing time and so on. From the point of view as the fluid dynamic, the effectiveness of the mixing, these are examined in detail.
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Shigeyuki TOMIMATSU, Yayoi YONAYAMA, Kazuo URANISHI
2004 Volume 24 Issue Supplement1 Pages
431-434
Published: July 01, 2004
Released on J-STAGE: December 08, 2009
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In order to reduce fluid loss, a guide vane is often used in a curved pipe. However, recently, some vibration or damage problems of the guide bane are reported. This is assumed that these problems are related to FIV (Flow Induced Vibration), but there are few researches about vibration or damage problems. In this paper, flow field around the guide vane in a curved circular pipe was studied. Recently, in order to reduce costs, a curved fitting is often used, instead of using a curved circular pipe. So, CFD analysis was conducted to check differences of flow field in a curved circular pipe and in a curved fitting. And there was no big difference between these results. In addition, PIV measurement was conducted to study instantaneous flow field behind a guide vane, and vortex shedding from the trailing edge of the guide vane was observed.
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Kunihiro HOSHINO, Hiroshi SAWADA, Masaru TSUJIMOTO, Katsuji TANIZAWA
2004 Volume 24 Issue Supplement1 Pages
435-438
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Visualization of three-dimensional shipping water flow on running ship foredeck was conducted at the wave basin of NMRI. Two high speed video cameras, a mirror and synchronous stroboscopic sheet light were mounted on starboard deck and the shipping water on portside deck was observed through the transparent current plate attached along the centerline of the model ship. In this paper, the results of shipping water flow by PIV and PTV analysis are presented.
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Hiroshi SAWADA, Kunihiro HOSHINO, Masaru TSUJIMOTO, Katsuji TANIZAWA
2004 Volume 24 Issue Supplement1 Pages
439-442
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Visualization of three-dimensional shipping water flow on running ship foredeck was conducted at the wave basin of NMRI. Two high speed video cameras, a mirror and synchronous stroboscopic sheet light were mounted on starboard deck and the shipping water on portside deck was observed through the transparent current plate attached along the centerline of the model ship. In this paper, the experimental technique for flow visualization is briefed and high speed video images are presented to show three dimensional features of shipping water motions.
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Yoshio SUZUKI, Kazunori SAI, Nobuaki OHNO, Koji KOYAMADA
2004 Volume 24 Issue Supplement1 Pages
443-446
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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An immersive type virtual reality (VR) system has been used as one of the visualization techniques for analyzing various complicated phenomena in a computational science. On the other hand, the volume rendering method is widely used for the intuitively understanding of 3-dimensionaly distributed physical quantities. Thus, it is very useful to apply the volume rendering method to the immersive VR system. However, a plane slice sampling method conventionally used in the volume rendering method has a problem that the quality of visualized images deteriorates in the immersive VR system. In this research and development, a sphere slice sampling method is applied to resolve this problem. In this presentation, the comparison between these two methods about the quality of image and the display speed has been performed. Further, the comparison between the hardware volume rendering method and software volume rendering method has been performed.
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Makoto KIKUGAWA, Kouji KOYAMADA
2004 Volume 24 Issue Supplement1 Pages
447-448
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The volume rendering using the hardware solid texture mechanism is very effective. However, the scope of this technique is restricted to a regular grid. In the case of an irregular grid, in order to apply this technique, voxelization is required. Usually, this processing spends much calculation cost. In this paper, we introduce the algorithm of efficient voxelization. Using 2-pass rasterization technique, this algorithm enables high-speed voxelization.
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Jorji NONAKA, Nobuyuki KUKIMOTO, Xuezhen LIU, Masato OGATA, Masanori K ...
2004 Volume 24 Issue Supplement1 Pages
449-450
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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In recent years, PC Clusters enhanced by high-performance consumer graphics cards have received increasing attention as an effective solution for real-time, high-resolution volume rendering of large data sets. However, the image composition process becomes a bottleneck when using traditional software approaches. Although several efficient algorithms have been proposed, their performance depends directly on the quantity of active pixels. Thus, accentuated performance degradation is expected during an immersive visualization where a screen is filled by active pixels. In this report, we present and evaluate a graphics cluster in its minimal configuration with a commercially available hardware image compositor manufactured by Mitsubishi Precision as a commodity hardware solution for the performance demands of immersive visualization as well as high-resolution visualization.
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Koji SAKAI, Naohisa SAKAMOTO, Koji KOYAMADA, Akio DOI
2004 Volume 24 Issue Supplement1 Pages
451-452
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Diffusion tensor magnetic resonance imaging (DT-MRI) is a technique used to measure the anistropic diffusion properties of the water molecules in the organism. And this technique has been utilized for the diagnosis of the diseases of brain as like a cerebral infarction, a brain tumor, and variable cases. On the other hand, the dissection is the only way to obtain the visible information of the neural pathway in the brain white matter with the exception of DT-MRI. The visualization technique called "tractography" allows the user to visualize the neural pathway from DT-MRI data that needs to set of the starting point and the end point of a pathway. These points have been set by user's medical intention and there has been no the other guideline. So, we calculated isotropic region in tensor field by using the DT-MRI data set, and proposed the technique which made the visible seed area information of neural pathways. In this paper, the method of the isotropic area computation from the DT-MRI data set and the flow of neural pathway of specified region ware shown with the suitable example.
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Katsumi KONISHI, Mitsuo ISHII, Kazuo IWASAWA
2004 Volume 24 Issue Supplement1 Pages
453-454
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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This paper focuses on volume data generated from medical CT/MRI images and provides a method for indexing and retrieval of volume data sets based on their 3D shape. The proposed method indexes volume data by calculating the distribution of its critical points, where the gradient is zero. Sine the volume data sets generated from medical CT/MRI images have a lot of critical points derived from measurement noise, a critical-point-based metric between volume data is obtained at high computational cost, and the size of indexing data is large. In order to reduce the number of critical points without loss of geometric features, Morse theory is applied. Retrieval examples show the efficiency of the proposed method.
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Sadanori OTAGIRI, Katsuhiko HIROTA, Yoshio SUZUKI, Yasuhiro WATASHIBA, ...
2004 Volume 24 Issue Supplement1 Pages
455-456
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Nowadays, a huge volume datasets has been generated from numerical simulations and measurement equipments. However the classification and reference has been usually performed manually, such as vision or experience of a measurement engineer. There still has not been revealed efficient techniques for searching similarity between volumetric datasets.
In this report, we propose a technique of performing the classification and reference using the critical point graph which expresses the feature of volume datasets in the simple figure. For this purpose, critical point graphs need to be generated efficiently and it is necessary to calculate the critical point in volume datasets efficiently.
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Youji Matsumoto, Yoshihito Kikkawa, Nobuyuki Kukimoto
2004 Volume 24 Issue Supplement1 Pages
457-458
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Multipurpose visualization toolkit AVS/Express provides visualization function as an object called "module" and user can change visualization parameters (e.g. level of isosuface, slice axis and plain) interactively. However in VR environment (e.g. CAVE), It is difficult for observer to change visualization parameters. We improve the user interface to change visualization parameters using simple menu on PDA within the CAVE environment. Using the PDA device, users can easily change visualization parameters in VR environment.
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Takayuki ITOH, Hiroki TAKAKURA, Atsushi SAWADA, Minoru KAWAHARA, Koji ...
2004 Volume 24 Issue Supplement1 Pages
459-462
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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IDS (Intrusion Detection System) is an active research topic for the purpose of cost reduction of security maintenance of computer network. However, existing IDS technologies still have some issues, including enormous log output data, and lack of analysis technologies of complicated behavior of recent intrusions. This report proposes a technique to support understanding and exploration of such behavior of intrusions, by applying an information visualization technique. The technique constructs hierarchical data according to IP addresses of computers in a target network, and visualizes the data by Heiankyo-view, which is a new technique for hierarchical data visualization. By mapping statistics of intrusions onto the visualization display, we could observe some behavior of real intrusions.
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Takayuki ITOH, Koji KOYAMADA, Nobuaki SARAI, Shohei HIDO
2004 Volume 24 Issue Supplement1 Pages
463-466
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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Computational simulation became popular not only in the fields of physics or chemistry, but also medical, engineering, finance, and so on. Discovery of the best simulation parameters is an issue in order to fit the result of simulations to real experimental results. This paper presents a system that realizes interactive optimization of such simulation parameters with a visualization technique and distributed computing architecture. The system iteratively executes simulations with gradually varying parameters, and then records the errors of simulation results. Then the system visualizes the distribution of the errors by Heiankyo-View, a novel hierarchical data visualization technique. We assume that there are multiple local-minimum errors in the distribution, but the visualization results help users to interactively choice the best parameters, or continue simulations with interactively varying the parameters.
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Takayuki SAGA, Koji OKAMOTO
2004 Volume 24 Issue Supplement1 Pages
467-468
Published: July 01, 2004
Released on J-STAGE: July 31, 2009
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The Web3D system has been widely used in the internet. It can show the 3D objects easily and friendly. On our "Web3D collaboration system", the Web3D is used as the interface of the visualization tool. The 3D objects have been transferred from the server using HTTP with the "Viewpoint", one of the commercialized Web3D. The multi-client system enables the visualization of the real-time simulation results with remote site. All clients can see the same results, simultaneously. This means that we can hold the remote collaboration with the real-time simulation. Also, the system has the feedback system, which controls the simulation parameter remotely. The transferred simulation data are displayed on the web, in real-time. In this paper, we install "Flash", very popular rich media software, on our system to improve its generallity.
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