• Journal of the Korean Society of Visualization
• /
• v.8 no.1
• /
• pp.31-38
• /
• 2010

An experimental study to evaluate dynamic structures of flow and turbulence characteristics in bubble-driven liquid flow in a rectangular tank with a varying flow rate of compressed air is conducted. Liquid flow fields are measured by time-resolved particle image velocimetry (PIV) with fluorescent tracer particles to eliminate diffused reflections, and by an image intensifier to acquire enhanced clean particle images. Instantaneous vector fields are investigated by using the two frame cross-correlation function and bad vectors are eliminated by magnitude difference technique. By proper orthogonal decomposition (POD) analysis, the energy distributions of spatial and temporal modes are acquired. When Reynolds number increases, bubble-induced turbulent motion becomes dominant rather than the recirculating flow near the side wall. The total kinetic energy transferred to the liquid from the rising bubbles shows a nonlinear relation regarding the energy input because of the interaction between bubbles and free surface.

• Proceedings of the Korean Institute of Interior Design Conference
• /
• 2004.11a
• /
• pp.66-71
• /
• 2004

The purpose of this study is to identify the problems that a current day care center has by analyzing the space arrangement, and to come up with the suggestion that would improve the arrangement along with the interior design of the day care center by studying the usage of materials, colors, lightings and furniture. The result of this study to follow problems were identified. 1. Classrooms also served as sleeping areas, therefore those two areas needed to be separated. 2. The kitchen was too small for the number of children. So they need separated kitchen and dining room. 3. The day care center remodeled from the ordinary house was wrose than other facilities in material, color pattern and design for child-care. 4. A lot of fluorescent light and bulb were used without enough windows to let natural sunlight in. 5. The restroom was so small that it caused uncomfortability to children. Based on the problems above, we could reach to a following conclusion. Use of primary colors could brighten the image of a room, and feature or creative arrangement of furniture may make it intriguing. With the increase in the expectation and attention to the young kids, the facilities should change according to them and be designed for the children. It is needed to study about whether the space and the elements of the emotional image were applied properly.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.12 no.1
• /
• pp.74-82
• /
• 2004

Planar laser-induced fluorescence(PLIF) has been widely used to obtain two dimensional fuel distribution. Acetone PLIF is chosen because fluorescence signal from acetone as a fluorescent tracer is less sensitive to oxygen quenching than other dopants. Acetone PLIF is applied to measure quantitative air excess ratio distribution in an engine fueled with LPG. Acetone is excited by KrF excimer laser (248nm) and its fluorescence image is acquired by ICCD camera with a cut-off filter to suppress Mie scattering from the laser light. For the purpose of quantifying PLIF signal, an image processing method including the correction of laser sheet beam profile is suggested. Raw images are divided by each intensity of laser energy and profile of laser sheet beam. Inhomogeneous fluorescence images scaled with the reference data, which is taken by a calibration process, are converted to air excess ratio distribution. This investigation shows instantaneous quantitative measurement of planar air excess ratio distribution for gaseous fuel.

• Current Optics and Photonics
• /
• v.5 no.3
• /
• pp.298-305
• /
• 2021

Modern distance sensing methods employ various measurement principles, including triangulation, time-of-flight, confocal, interferometric and frequency comb. Among them, the triangulation method, with a laser light source and an image sensor, is widely used in low-cost applications. We developed an omnidirectional two-dimensional (2D) distance sensor based on the triangulation principle for indoor floor mapping applications. The sensor has a range of 150-1500 mm with a relative resolution better than 4% over the range and 1% at 1 meter distance. It rotationally scans a compact one-dimensional (1D) distance sensor, composed of a near infrared (NIR) laser diode, a folding mirror, an imaging lens, and an image detector. We designed the sensor layout and configuration to satisfy the required measurement range and resolution, selecting easily available components in a special effort to reduce cost. We built a prototype and tested it with seven representative indoor wall specimens (white wallpaper, gray wallpaper, black wallpaper, furniture wood, black leather, brown leather, and white plastic) in a typical indoor illuminated condition, 200 lux, on a floor under ceiling mounted fluorescent lamps. We confirmed the proposed sensor provided reliable distance reading of all the specimens over the required measurement range (150-1500 mm) with a measurement resolution of 4% overall and 1% at 1 meter, regardless of illumination conditions.

• Journal of Animal Reproduction and Biotechnology
• /
• v.36 no.1
• /
• pp.17-24
• /
• 2021

In this study, the potential toxicity of isoprocarb was demonstrated using zebrafish embryos. We treated isoprocarb (0, 29, and 58 mg/L) to the zebrafish embryos for 72 h then, we estimated morphological changes and apoptotic cell numbers. The increasing extent of apoptosis from the anterior to posterior region of developing zebrafish larvae was correlated with toxicity in the overall development process, including growth and normal organ formation. The appearance of abnormalities in the isoprocarb-treated groups in comparison to normal developing zebrafish larvae was verified using quantitative image analysis based on ImageJ software program. The vascular system comprising a complex interconnection of blood vessels was visualized in vessel-fluorescent transgenic zebrafish (fli1:eGFP). The main vasculature was malformed on isoprocarb treatment, and this was also related to cardiac defects. Taken together, normal embryonic development in zebrafish was interrupted owing to the acute toxicity of isoprocarb.

• International Journal of Vascular Biomedical Engineering
• /
• v.1 no.2
• /
• pp.30-35
• /
• 2003

Flow characteristics of blood flow in a micro channel were investigated experimentally using a micro-PIV (Particle Image Velocimetry) velocity field measurement technique. The main objective of this study was to understand the real blood flow in micron-sized blood vessels. The Reynolds number based on the hydraulic diameter of micro-channel for deionized (DI) water was about Re=0.34. For each experimental condition, 100 instantaneous velocity fields were captured and ensemble-averaged to get the spatial distributions of mean velocity. In addition, the motion of RBC (Red Blood Cell) was visualized with a high-speed CCD camera. The captured flow images of nano-scale fluorescent tracer particles in DI water were clear and gave good velocity tracking-ability. However, there were substantial velocity variations in the central region of real blood flow in a micro-channel due to the presence of red blood cells.

• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.9
• /
• pp.22-29
• /
• 1997

This paper describes a three dimensional profile measurement method for sheet metal products which have flexible and porous sculptured surfaces. Shadow masks are used as measuring objects for practical implementation or this study. The shadow masks are located inside the fluorescent glasses of monitors for televisions or computers and used to prevent electron guns from interfering between pixels. Three dimen- sional surface profiles are measured by adopting a software autofocusing technique to capture focused images. The experimental results show that the method is very effecive and suitable for sheet meal prod- ucts with flexible and porous surfaces.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.1
• /
• pp.222-226
• /
• 2007

We suggest the fluorescence endoscope system that has light source apparatus providing selectable white or excitation light. White light source generates normal color images and is easily switched over to excitation light with the wide spectrum range from 380 nm to 580 nm. 5-ALA is deposited selectively in the abnormal tissue like cancer and causes fluorescence in the red spectrum range when excited by blue spectrum range. In addition, the others of excitation light make the color background image by reflected light to allow accurate orientation and visualization of the abnormal tissue and around. According to clinical studies, the fluorescence intensity contrast that defines the fluorescence intensity of lesion over the fluorescence intensity of around has more than 2 in tumour. Proposed system is useful and objective way in early diagnosis. Furthermore, it can be used in the biopsy for tumour classification at the highest fluorescence intensity point.

• Journal of Korean Institute of Industrial Engineers
• /
• v.22 no.2
• /
• pp.165-177
• /
• 1996

This paper presents a navigation method for a mobile robot which can follow a path drawn on a monitor screen. The current position and heading direction of the mobile robot are obtained using a single camera from a single image of the guide mark projected on a convex mirror. This proposed method eliminates the need to rotate or tilt the camera to track the guide mark, because the convex mirror and a stationary camera provide a panoramic view of the surrounding area. As guide marks, fluorescent lamps on the ceiling, door frames, or any other natural line segment can be used without adding any artificial elements to them.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.12
• /
• pp.2253-2260
• /
• 2007

A series of tetra donor substituted [2.2]paracyclophane-based two-photon absorption (TPA) fluorophores were synthesized in neutral and cationic forms. The imaging activity of overall set of fluorophores was studied by the two-photon induced fluorescence (TPIF) method in a range of solvents. We also measured a clear progression toward a longer photoluminescence lifetime with increasing solvent polarity (intrinsic photoluminescence lifetime, τi: ~2 ns in toluene → 12-16 ns in water). The paracyclophane fluorophores with this unique property can be utilized as an optical polarity probe for the biomolecular substrates. The combined measurement of the two-photon fluorescence microscopy (TPM) cell image and TPIF lifetime can give us a better understanding of the biological processes and local environments in the cells.