• Journal of The Korean Astronomical Society
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• v.49 no.6
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• pp.289-293
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• 2016

We investigate the long-term spatial drift of the center and the temporal variation of the shutter delay time map of Y4KCam mounted on the CTIO 1.0 m telescope. We have collected shutter delay time maps over eight years as a part of our long-term survey program. We find that the center of the shutter delay time map can drift up to $450{\mu}m$, equivalent to ${\approx}30pixels$, on the CCD. This effect can result in a small amount of error in integration time without the proper shutter delay time correction, but it does not appear to cause any significant problems in photometric measurements. We obtain a mean shutter delay time of $69.1{\pm}0.8$ ms and find no temporal variation of the shutter delay time of Y4KCam over eight years, indicative of the mechanical stability of the shutter. We suggest that using a master shutter delay time correction frame would be sufficient to achieve high precision photometry, which does not exceed photometric errors ${\approx}1.7mmag$ across the CCD frame for exposure times longer than 1 s.

• Journal of Broadcast Engineering
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• v.12 no.4
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• pp.350-359
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• 2007

In this paper we present a simple, efficient method for detection of sharp digital images. Recently many digital cameras are equipped with various autofocusing functions to help users take well-focused pictures as easily as possible. However, acquired digital pictures can be further degraded by motion, limited contrast, and inappropriate amount of exposure, to name a few. In order to decide whether to process the image or not, or whether to delete it or not, reliable measure of image quality to detect sharp images from blurry ones is needed. This paper presents a blurriness/sharpness measure, and demonstrates its feasibility using extensive experiments. This method is fast and easy to implement, and accurate. Regardless of the detection accuracy, existing measures are computation-intensive. However, the proposed measure in this paper is not demanding in computation time. Needless to say, this measure can be used for various imaging applications including autofocusing and astigmatism correction.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.2
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• pp.100-105
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• 2004

The influencing factors on the OPC (optical proximity correction) results are quantitatively analyzed using OPCed L/S patterns. ${\sigma}$ values of proximity variations are measured to be 9.3 nm and 15.2 nm for PR-A and PR-B, respectively. The effect of post exposure bake condition is assessed. 16.2 nm and 13.8 nm of variations are observed. Proximity variations of 11.6 nm and 15.2 nm are measured by changing the illumination condition. In order not to seriously deteriorate the OPC, these factors should be fixed after the OPC rules are extracted. Proximity variations of 11.4, 13.9, and 15.2 nm are observed for the mask mean-to-targets of 0, 2 and 4 nm, respectively. The decrease the OPC grid size from 1 nm to 0.5 nm enhances the correction resolution and the OCV is reduced from 14.6 nm to 11.4 nm. The enhancement amount of proximity variations are 9.2 nm corresponding to 39% improvement. The critical dimension (CD) uniformity improvement for adopting the small grid size is confirmed by measuring the CD uniformity on real SRAM pattern. CD uniformities are measured 9.9 nm and 8.7 nm for grid size of 1 nm and 0.5 nm, respectively. 22% improvement of the CD uniformity is achieved. The decrease of OPC grid size is shown to improve not only the proximity correction, but also the uniformity.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3517-3523
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• 2010

Single exposure dual X-ray imaging can be used to separate soft and dense-material images for medical and industrial applications. This study keep focusing baggage inspection system(BIS) specifically. New detector modules for single exposure dual X-ray imaging are consisted of low energy detector (LED) and high energy detector (HED). First, the optimized thickness of copper filter coupled HED to separate low energy and high energy was simulated by the given X-ray energy (140 kVp, 1 mA) using Monte Carlo simulation codes, MCNPX. So as a result of simulation, the copper filter thickness is 0.7 mm. For the design of PIN photodiode, ATLAS device simulation tool was used. 16 channels PIN photodiode of 1.5 mm ${\times}$ 3.2 mm for Dual X-ray imaging detector was fabricated in the process of ETRI. And its dark current and quantum efficiency, terminal capacitance were measured. It was proven that the Lanex Fast B coupled HED were a sufficient candidate to replace the CsI(Tl) commerced in dual X-ray system, since these give a strong signal, overcoming system noise. Finally dual X-ray image was acquired through correction of the LED X-ray Image and the HED X-ray Image.

• Archives of Plastic Surgery
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• v.43 no.2
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• pp.172-180
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• 2016

Background Conventional frontalis transfer may cause a range of complications. In order to overcome complications, we made modifications to the surgical technique, and compared the outcomes of patients who underwent conventional frontalis transfer with those of patients who underwent modified frontalis transfer. Methods We conducted a retrospective study of 48 patients (78 eyes) who underwent conventional frontalis transfer between 1991 and 2003 (group A) and 67 patients (107 eyes) who underwent modified frontalis transfer between 2004 and 2014 (group B). The frontalis transfer procedures were modified conform to the following principles. The tip of the frontalis muscle flap included soft tissue that was as thick as possible and the soft tissue on the tarsal plate was removed to the greatest extent possible. A double fold was created in cases of unilateral ptosis. In order to evaluate the objective effects of modification, preoperative and postoperative values of the marginal distance reflex 1 (MRD1), the corneal exposure area, and the decrease in eyebrow height were compared between the two groups. Results In group A, patients showed an improvement of 1.19 mm in the MRD1, a 6.31% improvement in the corneal exposure area, and a 7.82 mm decrease in eyebrow height. In group B, patients showed an improvement of 2.17 mm in the MRD1, an 8.39% improvement in the corneal exposure area, and an 11.54 mm decrease in eyebrow height. The improvements in group B were significantly greater than those in group A. Conclusions Modified frontalis transfer showed better results than the conventional procedure and provided satisfactory outcomes.

• Genomics & Informatics
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• v.8 no.1
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• pp.28-33
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• 2010

Increased exposure of human to RF fields has raised concerns for its potential adverse effects on our health. To address the biological effects of RF radiation, we used genome wide gene expression as the indicator. We exposed normal WI-38 human fibroblast cells to 1763 MHz mobile phone RF radiation at a specific absorption rate (SAR) of 60 W/kg with an operating cooling system for 24 h. There were no alterations in cell numbers or morphology after RF exposure. Through microarray analysis, we identified no differentially expressed genes (DEGs) at the 0.05 significance level after controlling for multiple testing errors with the Benjaminiochberg false discovery rate (BH FDR) method. Meanwhile, 82 genes were differentially expressed between RF-exposed cells and controls when the significance level was set at 0.01 without correction for multiple comparisons. We found that 24 genes (0.08% of the total genes examined) were changed by more than 1.5-fold on RF exposure. However, significant enrichment of any gene set or pathway was not observed from the functional annotation analysis. From these results, we did not find any evidence that non-thermal RF radiation at a 60-W/kg SAR significantly affects cell proliferation or gene expression in WI-38 cells.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.725-731
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• 2011

In this study, a survey was carried out on 300 students in Korea Culinary Arts Science High School located in Gyeonggi-do from August 1 to August 30, 2011 to figure out how the control of high school students' eating behavior affects the change of their psychological achievement. Analysis showed that attitude toward eating behavior, and perceived behavior that recognize this and act, as eating habits for control of their eating behavior, are the most control factors of eating behavior. It says that the right perception of customary attitude and the correction of habits according to the exposure and performance of repetitive eating behaviors are important. Consequently, an ordinarily regular norm as a social norm, or a rule around it won't act as big positive factors.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.55-61
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• 1990

Patients with facial paralysis, in whom nerve damage is irreparable or in whom the innervation of the paralyzed musculature cannot be restored by nerve suture, grafting, or cross-face nerve transplantation, should be offered some form of reconstructive static and dynamic aid. Temporalis muscle-fascia unit used as a circumorbital sling and motor unit is a dynamic controlled reconstructive procedure, but it has several disadvantages such as wide surgical exposure, bulky-looking at lateral canthal area, insufficient voluntary control. This is a case report of facial palsy of posttraumatic lagophthalmos of 41-year-old male, which was corrected by temporalis muscle-tendon transfer with plantaris tendon transplantation.

• Publications of The Korean Astronomical Society
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• v.14 no.1
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• pp.47-56
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• 1999

We have improved the control and driving system of 16' reflector at Kwanak Observatory at Seoul National University, by completing encoder unit, and by developing programs for correction of errors resulting from hardware defects. The hardware defects of this telescope system are the large backlash and the nonuniform tracking and pointing. The telescope pointing accuracy for RA is improved to a few arc minutes, and that for DEC is several tens of arc minutes. The guiding error is improved to 0.7 arcsec/minute, allowing up to 3 minutes exposure for CCD imaging under typical seeing conditions at the Observatory.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.3
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• pp.568-574
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• 1997

Inverted maxillary incisor is a state in which the maxillary incisor rotates to the upward position. The present report provides two examples of correction of inverted maxillary incisors with surgical intervention & orthodontic appliance. Through surgical exposure & direct bonding of lingual button, the central incisor were brought into proper eruption path with elastic traction. The case 1 & 2 were both treated successfully. The results showed the good position of treated teeth and satisfactory esthetics and adequate width of keratinized gingiva were achieved. Careful differential diagnosis procedure is needed in order to avoid dissatisfactory results and the treatment approaches taken in this case report provided an esthetic and functional results.