• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.506-509
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• 2002

An optical system for a stereoscopic video recorder is designed with the field of view 42$^{\circ}$ and effective diameter 22 mm. We can use it by attaching it to the front lens of any video camera or camcorder to record a stereoscopic scene. This system is a double Kepler type afocal system to make the image erect and a bi-ocular type to record and display the stereoscopic scene. The optical tube length is folded with several flat mirrors and a beam splitter to be compact. This optical system is composed of 4 groups of lenses and each group serves as a relay lens for minimizing the vignetting effect. Whole field stereoscopic scenes may be captured by perpendicularly polarized alternated recording with a chopper and two perpendicular polarizers, without any loss of light energy. The displayed images may be seen stereoscopically with polarized spectacles and are kinetic because of an afterimage effect.

• KIEAE Journal
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• v.3 no.3
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• pp.19-25
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• 2003

The Address No.0 of Eco-friendly Architecture offers unique experience for those who visit the place to envisage the future architecture where nature, human and building exist in harmony. It is open to the general public including the students of elementary and secondary schools. This house has been built to provide opportunities for the general public to experience eco-friendly architecture. It's floor area is 42 pyung($140m^2$) and the overall site has the area of 180 pyung($600m^2$). The following illustrates some of its prominent features : ${\bullet}$ Remodeling of a traditional Korean residence ${\bullet}$ Application of passive solar systems ${\bullet}$ Use of clerestory windows and daylighting systems(washroom and machine room) ${\bullet}$ Operation of solar water heaters with flat plate collectors ${\bullet}$ Construction of Biotop(small ecological world) ${\bullet}$ Water circulation for Biotop by photovoltaic(150W) and wind power(400W) generation ${\bullet}$ Outdoor hot water supplied by all-glass evacuated solar tubes. Through this Address No.0 of Eco-friendly Architeture conclusions are as followings. 1. The array of tubes in collector has the best nice in that the number of tube is nine and the tilt angle is the latitude $+20^{\circ}$. 2. The thermal performance of the all-glass solar vacuum collector was excellent than of the flate-plate solar collector. 3. The adaption of new small wind power systems to buildings were proved to produce a profit if it is considered the expense of environment improvement and the wind speed increasing according to rise of building hight.

• Journal of radiological science and technology
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• v.4 no.1
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• pp.55-62
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• 1981

This study was conducted, during the period of 20-30th, July in 1981, to survey measurement methods in thyroid uptake rate test in Seoul city. The results were summarized as follows: 1. For the great part of nuclear medcine department, a mount of radioiodine($^{131}I$) administrated to the patients was $50-100{\mu}Ci$ in thyroid uptake rate test. 2. Distribution of scintillation, counter with crystal size of $1\frac{1}{2}inch$ was 43%, 3inch(22%), 2.5inch(14%) and $2\frac{1}{2}inch$ was 7% in RAI uptake rate test. 3. When RAI uptake rate test was performed, distribution of collimator in use was flat field type collimator(78%) in general and cylindrical type collimator was 22%. 4. High voltage applied to the P-M tube was $900{\sim}1000V$(50%) and most units provided $3{\sim}15%$ of the window range for the $^{131}I$ peak $\gamma-ray$ energy. 5. Distribution on the use of neck phantom for measurements standard solution was 57% and distribution of b filter in use for room background counts and extrathyroidal tissue was 43% and 50%. 6. The distance between the counter and the source was 25cm(58%) in measuring radioactivity of standard solution, thyroid tissue and background radioactivity count. 7. The early uptake measurements(2, 4, 6 hours) are done after administration of the radioiodine dose and also 24-hour and 48-hour uptake measurements are done in routine test.

• FLOWER RESEARCH JOURNAL
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• v.17 no.3
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• pp.197-200
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• 2009

A new grafted cactus cultivar, G. 'Gohong', was developed by crossing 'DR' line with dark red color and G. 'Seolhong' with dark red color in 2004. It grew for 6 months after grafting in vitro and culturing at 100 mL test tube. After grafting and planting in greenhouse in 2005, various characteristics were evaluated three times until 2008. It has flat-round shape and dark red skin. In addition, it has 8 to 10 ribs and gray and straight spines on the body. The diameter of it was 44.1 mm after 10 months. It grew bigger and faster comparing with G 'Seolhong' cultivar. The ability of propagation in G. 'Gohong' is similar to that of G. 'Seolhong' producing approximately 12.1 daughter globes for 10 months after planting.

• FLOWER RESEARCH JOURNAL
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• v.19 no.4
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• pp.248-250
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• 2011

A new grafted cactus cultivar, G. mihanovichii 'Ihong', for exporting abroad, was developed by crossing G. mihanovichii 'DR' line with dark red color, and G. mihanovichii 'Seolhong' cultivar with dark red in 2005. It grew for 6 months after grafting in vitro and culturing at 100 mL test tube. After grafting and planting in greenhouse in 2006, various characteristics were evaluated three times until 2009. It has flat round shape and dark red skin. In addition, it has 8 to 10 ribs and brown straight spines on the body. Its diameter was 44.0 mm after 10 months from planting, and bigger comparing with that of 'Seolhong' cultivar. The ability of propagation in 'Ihong' was better than that of 'Seolhong' and 'Ihong' approximately produced 15.8 offsets for 10 months.

• FLOWER RESEARCH JOURNAL
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• v.16 no.3
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• pp.196-199
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• 2008

A new grafted cactus variety, 'Dahong', Gymnocalycium mihanovichii, is hybrid crossed between '9508021' line with red and black color, and 'Jinhong', with dark red color in 2002. It was cultivated for 6 months after grafted in vitro and planted at 100 mL test tube. After grafting in vivo in 2003, the various characteristics of this was evaluated three times until 2006. It has the flat-round shape and dark red skin, and produces the daughter globes at areoles, which are arranged well at the low part of globe. In addition, it has 8~10 ribs and the gray and slant spines in body. The ability of propagation is better than 'Jinhong' to produce approximately 13.6 daughter globes.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.291-294
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• 2010

A new grafted cactus cultivar, G. mihanovichii 'Hwangun', for exporting abroad, was developed by crossing G. mihanovichii 'Hwangwol' variety with yellow and orange color, and G. mihanovichii '0111021' line with yellow color in 2008. It grew for 6 months after grafting in vitro and culturing at 100 mL test tube. After grafting and planting in greenhouse in 2005, various characteristics were evaluated three times until 2008. It has flat-round shape and bright yellow skin. In addition, it has 7 to 9 ribs and brown straight spines on the body. The diameter of it was 40.9 mm after 10 months after planting, and small comparing with G. mihanovichii 'Hukwang' cultivar. The ability of propagation in G. mihanovichii 'Hwangun' is prior to that of G. mihanovichii 'Hukwang' producing approximately 22.3 daughter globes for 10 months.

• ETRI Journal
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• v.41 no.1
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• pp.23-31
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• 2019

Since the late 20th century, there has been rapid development in the display industry. Only 30 years ago, we used big cathode ray tube displays with poor resolution, but now most people use televisions or smartphones with very high-quality displays. People now want images that are more realistic, beyond the two-dimensional images that exist on the flat screen, and digital holography-one of the next-generation displaysis expected to meet that need. The most important parameter that determines the performance of a digital hologram is the pixel pitch. The smaller the pixel pitch, the higher the level of hologram implementation possible. In this study, we fabricated the world-smallest $3-{\mu}m$-pixel-pitch holographic backplane based on the spatial light modulator technology. This panel could display images with a viewing angle of more than $10^{\circ}$. Furthermore, a comparative study was conducted on the fabrication processes and the corresponding holographic results from the large to the small pixel-pitch panels.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.655-668
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• 2023

In radiography, an antiscatter grid is a well-known device for eliminating unexpected x-ray scatter. We investigate a new stationary grid artifact suppression method based on a nonsubsampled contourlet transform (NSCT) incorporated with Gaussian band-pass filtering. The proposed method has an advantage that extracts the Moiré components while minimizing the loss of image information and apply the prior information of Moiré component positions in multi-decomposition sub-band images. We implemented the proposed algorithm and performed a simulation and an experiment to demonstrate its viability. We did this experiment using an x-ray tube (M-113T, Varian, focal spot size: 0.1 mm), a flat-panel detector (ROSE-M Sensor, Aspenstate, pixel dimension: 3032 × 3800 pixels, pixel size: 0.076 mm), and carbon graphite-interspaced grids (JPI Healthcare, 18 cm × 24 cm, line density: 103 LP/inch and 150 LP/inch, ratio: 5:1, focal distance: 65 cm). Our results indicate that the proposed method successfully suppressed grid artifacts by reducing them without either reducing the spatial resolution or causing negative side effects. Consequently, we anticipate that the proposed method can improve image acquisition in a stationary grid x-ray system as well as in extended x-ray imaging.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.6
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• pp.469-477
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• 2008

Purpose: The goal of this paper is to present the design and performance of a position encoding circuit for $16{\times}16$ array of position sensitive multi-anode photomultiplier tube for small animal PET scanners. This circuit which reduces the number of readout channels from 256 to 4 channels is based on a charge division method utilizing a resistor array. Materials and Methods: The position encoding circuit was simulated with PSpice before fabrication. The position encoding circuit reads out the signals from H9500 flat panel PMTs (Hamamatsu Photonics K.K., Japan) on which $1.5{\times}1.5{\times}7.0\;mm^3$ $L_{0.9}GSO$ ($Lu_{1.8}Gd_{0.2}SiO_{5}:Ce$) crystals were mounted. For coincidence detection, two different PET modules were used. One PET module consisted of a $29{\times}29\;L_{0.9}GSO$ crystal layer, and the other PET module two $28{\times}28$ and $29{\times}29\;L_{0.9}GSO$ crystal layers which have relative offsets by half a crystal pitch in x- and y-directions. The crystal mapping algorithm was also developed to identify crystals. Results: Each crystal was clearly visible in flood images. The crystal identification capability was enhanced further by changing the values of resistors near the edge of the resistor array. Energy resolutions of individual crystal were about 11.6%(SD 1.6). The flood images were segmented well with the proposed crystal mapping algorithm. Conclusion: The position encoding circuit resulted in a clear separation of crystals and sufficient energy resolutions with H9500 flat-panel PMT and $L_{0.9}GSO$ crystals. This circuit is good enough for use in small animal PET scanners.