• Journal of the Optical Society of Korea
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• 제14권4호
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• pp.316-320
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• 2010

We report an application of full-field optical coherence tomography (FF-OCT) for identifying counterfeit bank notes. The depth-resolved imaging capability of FF-OCT was used for tomographic identification of superficially-identical objects. By retrieving the internal structures of the security feature (cash hologram) of an original banknote, we could demonstrate the feasibility of FF-OCT to identify counterfeit money. The FF-OCT images showed that the hologram consisted of micron scale multi-coated layers including an air gap. Therefore, it is expected that FF-OCT has potential as a new non-invasive tool to discern imitation of currency, and it would find applications in a wide field of counterfeit sciences.

• Current Optics and Photonics
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• 제3권6호
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• pp.571-576
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• 2019

The morphological changes of anthracnose (fungus) -infected tomato seeds have been studied to identify the infection and characterize its effect. Full-field optical coherence tomography (FF-OCT) has been utilized as a nondestructive but efficient modality for visualizing the effects of fungal infection. The cross-sectional images extracted from a stack of en face FF-OCT images showed significant changes with infection in the seed structure. First of all, the seed coat disappeared with the infection. The thickness of the seed coat of a healthy seed was measured as 28.2 ㎛, with a standard deviation of 1.2 ㎛. However, for infected seeds the gap between surface and endosperm was not appreciably observed. In addition, the measurements confirmed that the dryness of seeds did not affect the internal seed structure. The reconstructed three-dimensional (3D) image revealed that the permeability of the seed coat, which plays the vital role of protecting the seed, is also affected by the infection. These results suggest that FF-OCT has good potential for the identification of fungus-infected tomato seeds, and for many other tasks in agriculture.

• Journal of the Optical Society of Korea
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• 제13권3호
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• pp.341-348
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• 2009

We report the development of full-field swept-source optical coherence tomography (SS-OCT) in the wavelength range of 815-870 nm using a unique combination of super-luminescent diode (SLD) as broad-band light source and acousto-optic tunable filter (AOTF) as a frequency-scanning device. Some new applications of full-field SS-OCT in forensic sciences and engineering materials have been demonstrated. Results of simultaneous topography and tomography of latent fingerprints, silicon microelectronic circuits and composite materials are presented. The main advantages of the present system are completely non-mechanical scanning, wide-field, compact and low-cost.

• Journal of the Optical Society of Korea
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• 제11권1호
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• pp.18-25
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• 2007

We present an ultrahigh-resolution full-field optical coherence tomography (FF-OCT) implemented with a white-light interference microscope and a detector array as an alternative OCT technique. The use of detector array allows the capture of two-dimensional en-face images in parallel without taking any lateral scanning process. The phase shifting interferometric technique with the sinusoidal phase modulation (SPM) is utilized to get the demodulated OCT images. The configuration of the system and the resolution of the obtained image are presented. The topographic images, taken with the implemented system, of a coin, an integrated circuit chip, and the tomographic images of an onion epithelium are demonstrated also. Axial and lateral spatial resolution of ${\sim}1.0{\mu}m$ and ${\sim}2.0{\mu}m$ are achieved with the system respectively.

• Journal of Veterinary Science
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• 제22권5호
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• pp.65.1-65.12
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• 2021

Background: To assess the normal retina of the pigeon eye using spectral domain optical coherence tomography (SD-OCT) and establish a normative reference. Methods: Twelve eyes of six ophthalmologically normal pigeons (Columba livia) were included. SD-OCT images were taken with dilated pupils under sedation. Four meridians, including the fovea, optic disc, red field, and yellow field, were obtained in each eye. The layers, including full thickness (FT), ganglion cell complex (GCC), thickness from the retinal pigmented epithelium to the outer nuclear layer (RPE-ONL), and from the retinal pigmented epithelium to the inner nuclear layer (RPE-INL), were manually measured. Results: The average FT values were significantly different among the four meridians (p < 0.05), with the optic disc meridian being the thickest (294.0 ± 13.9 ㎛). The average GCC was thickest in the optic disc (105.3 ± 27.1 ㎛) and thinnest in the fovea meridian (42.8 ± 15.3 ㎛). The average RPE-INL of the fovea meridian (165.5 ± 18.3 ㎛) was significantly thicker than that of the other meridians (p < 0.05). The average RPE-ONL of the fovea, optic disc, yellow field, and red field were 91.2 ± 5.2 ㎛, 87.7 ± 5.3 ㎛, 87.6 ± 6.5 ㎛, and 91.4 ± 3.9 ㎛, respectively. RPE-INL and RPE-ONL thickness of the red field meridian did not change significantly with measurement location (p > 0.05). Conclusions: Measured data could be used as normative references for diagnosing pigeon retinopathies and further research on avian fundus structure.

• 한국초지조사료학회지
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• 제24권1호
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• pp.53-60
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• 2004

Recently, there has been a growing tendency to use whole crop rice for feeds as there is an increased rice supply and a decrease in the demand for rice in Korea. Little information, however, is available about the management and utilization of whole crop rice for feeds. This study was conducted to decide the optimum harvest date through examining the plant height, dry matter(DM) yield and feed composition of whole crop rice harvested at different maturity. Field study was established early in May until October 7th on a rice field at Yupori, Sinbuk-yeup, Chunchon, Kangwon-Do. "Ilpum" mutant rice was sown at 52 kg/ha, and N, P and K were applied at 209, 113 and 81 kg/ha, respectively. The rice was harvested at six different mature stages for analysis; booting stage; 17 Aug., milk-ripe stage; 27 Aug., dough stage; 7 Sep., yellow ripe stage; 17 Sep., dead ripe stage; 27 Sep. and full ripe stage; 7 Oct. Plant height was 77 cm in booting stage (P<0.05) which was lower when compared to the other stages among which the heights did not differ with average range of 93∼97 cm. The highest dry matter yield was observed in yellow ripe stage (22.8 T/ha), which was followed by dead ripe stage (19.3 T/ha), full ripe stage (19.3 T/ha), and dough stage (15.1 T/ha). Crude protein (CP) and Neutral detergent fiber (NDF) concentrations consistently decreased with maturity. The highest concentrations of CP and NDF were obtained in booting stage with 9 and 73.6%, respectively (P<0.05), and lowest in full ripe stage with 5.8 and 64.6%, respectively (P<0.05). The concentration of total digestible nutrient (TDN) was highest in booting stage (59.7%); however no significant difference was found among other stages. The concentrations of Ca and P were not different among mature stages. According to these results, the yellow ripe period is appropriate to harvest the whole crop rice for forage considering dry matter yields, feed compositions and TDN concentrations.

• 대한토목학회논문집
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• 제13권5호
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• pp.209-222
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• 1993

본 고는 폐기물 매립지반의 지반개량을 위하여 1992년 3월 16일부터 1992년 10월 25일까지 수행된 동다짐공사 결과에 대한 연구사례이며, 개량대상지역은 대전시 갑천변에 위치하는 폐기물 매립부지로 1983년부터 1989년까지 주로 도시생활 쓰레기, 연탄재, 구조물 해체 잔해물 및 일부 산업폐기물로 매립되어 형성된 지역이다. 동다짐 공사는 2개 지점에서 시험동다짐을 시행하여 그 결과를 기준으로 수행되었으며, 개량효과 분석 및 품질관리를 위하여 각종 현장확인 시험 및 지반거동 계측을 수행하였다. 또한 동다짐시 인접된 구조물에 미치는 영향을 분석하기 위하여 진동측정을 시행하였다. 제반 현장시험 및 계측자료 분석결과 전체적으로 지반의 강도증가 및 압축효과가 양호한 것으로 확인되어 본 지역의 폐기물 매립지반에 대한 동다짐공법 적용은 효과적인 것으로 나타났으며, 향후 본 지역과 유사한 폐기물 매립지반에 대한 동다짐공법 적용시 참고가 될 수 있을 것으로 기대된다.

• 한국초지조사료학회지
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• 제24권1호
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• pp.61-70
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• 2004

벼 사일리지는 일반적으로 높은 pH와 많은 양의 butyric acid로 인하여 발효 품질이 좋지 못하기 때문에 발효품질 향상을 위해서 첨가제 처리가 요구된다. 하지만, 아직까지 국내에선 첨가제를 첨가하여 벼 사일리지의 발효품질에 대해서 검토된 바 없다. 따라서 본 연구는 생육시기별로 수확된 사료용 벼에 유산균 및 개미산의 첨가수준을 달리하여 사료성분과 발효품질의 변화를 조사하여 양질의 벼 사일리지를 조제를 위한 적정 첨가수준을 구명하기 위하여 수행되었다. 본 시험은 강원도 춘천시 신북읍 유포리에 위치한 기존 논에서 일품벼mutant(만생종)를 최초 8월 17일부터 10일 간격으로 6회(8월 17일; 수잉기, 8월 27일: 유숙기, 9월 7일; 호숙기, 9월 17일; 황숙기, 9월 27일; 고숙기, 및 10월 7일: 완숙기) 수확하여 수확시기별로 유산균 및 개미산을 각각 원료무게의 0.05, 0.1 및 0.2％ 와 0.2, 0.3 및 0.4％를 첨가하였다. 건물함량, 조단백질, 섬유소 및 TDN 함량은 모든 수확시기에서 첨가제 처리수준에 따른 유의적인 차이는 보이지 않았다. 유산균 및 개미산 처리가 모든 수확시기에서 무처리구에 비해서 낮은 pH를 나타냈으며, 각 첨가제 공히 첨가수준이 높아짐에 따라 pH가 낮아지는 경향을 나타냈다. 유산 함량은 각 수확시기 모두에서 유산균 및 개미산 처리구가 무처리구에 비해서 유의적으로 높았으며(P< 0.05), 유산균 처리구에서 더 많은 유산이 생성 되었다. 낙산 함량은 모든 수확시기에서 무 첨가구보다 첨가제 처리구에서 공히 낮았고 (P< 0.05), 첨가제 처리수준이 높아짐에 따라 낮아지는 경향을 보였다. 암모니아태 질소 함량은 모든 수확시기에서 첨가제 처리구가 무첨가구에 비해서 유의적으로 낮게 나타났으나(P< 0.05), 황숙기 이후에서 첨가수준에 따른 유의적 차이는 나타나지 않았다(P<0.05). 본 연구에서 발효품질은 첨가제 첨가수준이 높아짐에 따라 향상되는 경향을 보였지만, 낮은 처리수준에서도 양질의 사일리지 조제가 가능하였다. 따라서 양질의 벼 사일리지 조제를 위한 유산균과 개미산의 첨가수준은 각각 0.5∼0.1％와 0.2∼0.3％가 적정 수준인 것으로 사료된다.