• Journal of the Korean Geotechnical Society
• /
• v.21 no.9
• /
• pp.87-102
• /
• 2005

In the congested urban areas, tunnelling close to existing structures or services often occurs due to the lack of surface space so that tunnelling-induced ground movements may cause a serious damage to the adjacent structures. This study focused on the two dimensional laboratory model pile-soil-tunnelling interaction tests using a close range photogrammetric technique. Testing equipments and procedures were Introduced, particularly features of aluminium rods regarded as the frictional granular material. The experimental result showed that the photo imaging process by the VMS and EngVis programs proved to be a useful tool in measuring the pile tip movements during the tunnelling. Consequently, the normalised pile tip movement data for the influence zones can be generated by the laboratory model tests using the Photogrammetric technique. This study presents influence zones associated with the normalized pile tip settlements due to tunnelling in the cohesionless material. The influence zones were Identified by both a laboratory model test and a numerical analysis. The normalized pile tip movements from the model test were in good agreement with the numerical analysis result. The influence zones proposed in this study could be used to decide the reasonable location of tunnel construction in the planning stage. However, the scale of model pile and model tunnel sizes must be carefully adjusted as real ones for practical application considering the ground conditions at a given site.

• Proceedings of the Korean Society of Laser Processing Conference
• /
• 2005.11a
• /
• pp.37-41
• /
• 2005

When screen size of the Flat Panel Display (FPD) becomes larger, the traditional photo-lithography using photomasks and UV lamps might not be possible to make patterns on Photo Resist (PR) material due to limitation of the mask size. Though the maskless photo-lithography using UV lasers and scanners had been developed to implement large screen display, it was very slow to apply the process for mass-production systems. The laser exposure system using 405 nm semi-conductor lasers and Digital Micromirror Devices (DMD) has been developed to overcome above-mentioned problems and make more than 100 inches FPD devices. It makes very fine patterns for full HD display and exposes them very fast. The optical engines which contain DMD, Micro Lens Array (MLA) and projection lenses are designed for 10 to 50 ${\mu}m$ bitmap pattern resolutions. The test patterns for LCD and PDP displays are exposed on PR and Dry Film Resists (DFR) which are coated or laminated on some specific substrates and developed. The fabricated edges of the sample patterns are well-defined and the results are satisfied with tight manufacturing requirements.

• Bulletin of the Korean Chemical Society
• /
• v.28 no.12
• /
• pp.2195-2199
• /
• 2007

We demonstrate that high-resolution (~60 nm) near-field fluorescence images of fluorescent nanospheres can be obtained by utilizing the tip-induced fluorescence quenching process. A time-stamped photon counting (TSPC) technique employed enables us to efficiently measure the degree of fluorescence quenching caused by the dielectric or metallic atomic force microscopy tip. We find that the degree of quenching is not only determined by the tip-material but also by the local morphology of the tip. The fringe patterns around individual nanospheres observed are explained in terms of the interference between the excitation field that is directly induced by the laser source, and the scattered excitation field from the tip.

• Journal of the Korean Society for Computer Game
• /
• v.31 no.4
• /
• pp.137-144
• /
• 2018

In the past, mosaics were made by laying cloth on the floor and manually tiling the tiles. However, due to recent developments in technology, the data storage method has evolved from analog to digital, so that image representation and conversion can be realized through computer. Also, various expression techniques of mosaic are developed, and it is also used as a method of art representation in digital. There are various studies on the production process of mosaic. The proposed method is a crystallization mosaic that spreads spirally in real time and uses 3D quartz as a tile element. Although existing researches are mostly focused on the purpose of rendering images in more detail, this technique combines untried spiral drawing and crystallization, and attempts to explore new expression techniques in 3D space by attempting a new mosaic method in 3D space. 'Spiral Crystallization Photo', based on this technique, was selected as Top27 in MWU Award 18 and exhibited at Unite Seoul 2018.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.23 no.3
• /
• pp.323-330
• /
• 2005

More than ten years after the era of GPS-Photogrammetry which could provide us only three projection center of all six exterior orientation parameters, direct georeferencing with GPS/INS is now becoming a standard method for image orientation. Its main advantage is to skip or reduce the indirect ground control process. This paper describes the experimental test results of integrated sensor orientation with a commercial GPS/IMU system to approve its performance in determination of exterior orientation. For this purpose two different imaging blocks were planned and the area was photographed at a large photo scale of 1:5,000 and a medium photo scale of 1:20,000. From these data set a variety of meaningful results was acquired, i.e., the accuracy. potential of exterior orientation from direct georeferencing and combined block adjustment using these data considering different photo scales and conditions.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.7 no.4
• /
• pp.77-87
• /
• 2004

It is important for hydrographers to extract the accurate cross section of a river for the hydrographical analysis of the topography. Aerial photographs were used to extract the cross section of a river for the advantages of the accuracy and economical efficiency in this study, while the direct measurement has been used in existing studies. An ortho-rectified photo map using imageries taken by the PKNU 2 (High-resolution, multi-spectral, aerial photographic system developed by our laboratory) was generated using the surveyed data and a digital map. The cross section of a river that was obtained from the ortho-rectified by the surveyed Kinematic data of GPS was compared with the result using ImageStation stereo-plotter of corp. Z/I Imaging. As a result of this study, the RMSE in the ortho-rect process using the surveyed GPS data was lowered as from 5.5788 pixels (about 2m) to 2.84 (about 1m) in comparison with it in the process using a digital map. The surveyed kinematic GPS in extraction of the cross section of a river was excellent as 6.6cm of the planimetric and precision in the confidence level of 95%. The correlation coefficient between the result from the using stereo-plotter and the extraction of cross section of a river using aerial photos was 0.8 hydrographical acquisition of it using PKNU 2 imagery will be possible.

• Korean Journal of Optics and Photonics
• /
• v.14 no.1
• /
• pp.97-102
• /
• 2003

Multi-channel images of 11-MUA(11-Mercaptoundecanoic acid) and 11-MUOH(11-Mercaptoundecanol) self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. The patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each point on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching, which are common in the detection methods based on fluorescence.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.6 no.2
• /
• pp.102-115
• /
• 2020

In the state of Positronium (Ps), which is an unstable material created by the temporary combination of electrons and positrons, the imaging technology through photo-conversion methodology is emerging as a new research theme under resonance conditions through terahertz electromagnetic waves. Normally, Positronium can be observed in the positron emission computed tomography (PET) process when an unstable, separate state that remains after the pair annihilation of an electron and a positron remains. In this study, terahertz (THz) waves and Cherenkov radiation (CR) are generated using the principle of ponderomotive force in the plasma wake-field acceleration, and electrons and positrons are simultaneously generated by using a relativistic electron beam without using a PET device. We confirm the possibility of Positronium photoconversion technology in terahertz electromagnetic resonance conditions through experimental studies that generate an unstable state. Here, a relativistic electron beam (REB) energy of 0.5 MeV (γ=2) was used, and the terahertz wave frequencies is G-band. Meanwhile, a THz wave mode converting three-stepped axicon lens was used to apply the photoconversion technology. Through this, light emission in the form of a luminescence-converted Bessel beam can be verified. In the future, it can be used complementarily with PET in nuclear medicine in the field of medical imaging.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.19 no.6
• /
• pp.834-840
• /
• 2010

Photo lithography process is very important technology to fabricate highly integrated micro patterns with high precision for semiconductor and display industries. Up to now, mask type lithography process has been generally used for this purpose; however, it is not efficient for small quantity and/or frequently changing products. Therefore, in order to obtain higher productivity and lower manufacturing cost, the mask type lithography process should be replaced. In this study, a maskless lithography system using the DMD(Digital Micromirror Device) is developed, and the exposure condition and optical properties are analyzed and simulated for a single beam case. From the proposed experimental conditions, required exposure experiments were preformed, and the results were investigated. As a results, 10${\mu}m$ spots can be generated at optimal focal length.

• Journal of Korean Society for Geospatial Information Science
• /
• v.25 no.2
• /
• pp.21-29
• /
• 2017

For the efficient and stable operation of autonomous vehicles or advanced driver assistance systems being actively studied nowadays, it is important to determine the positions of the vehicle accurately and economically. A satellite based navigation system is mainly used for positioning, but it has a limitation in signal blockage areas. To overcome this limitation, sensor fusion methods including additional sensors such as an inertial navigation system have been mainly proposed but the high sensor cost has been a problem. In this work, we develop a vehicle position estimation algorithm using in-vehicle sensors and a low-cost imaging sensor without any expensive additional sensor. We determine the vehicle positions using the velocity and yaw-rate of a car from the in-vehicle sensors and the position and attitude of the camera based on the single photo resection process. For the evaluation, we built a prototype system, acquired test data using the system, and estimated the trajectory. The proposed algorithm shows the accuracy of about 40% higher than an in-vehicle sensor only method.