• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2022년도 학술발표회
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• pp.445-445
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• 2022

최근 새만금 방조제 건설이 완료됨에 따라 주변 연안지역의 지형에 많은 변화가 감지되었다. 본 연구대상지는 격포해수욕장으로서 새만금 사업 준공 후 연안침식에 따른 모래 유실 등으로 인해 양빈사업 등이 검토되고 있는 상황이다. 본 연구에서는 연안지형 변화 탐지를 위한 UAV (Unmanned Aerial Vehicle) 활용기술을 제시하는 것으로서 총 3회에 걸쳐 UAV 영상을 촬영하였다. 영상촬영은 DJI Inspire 2 UAV를 활용하였으며 VRS(Virtual Reference Service) 측량성과와 연계하여 Pix4D Mapper SW를 통해 정사영상과 수치표면모델(DSM; Digital Surface Model)을 제작하였다. 먼저 2018. 6. 29 ~ 2018. 12. 10 사이의 지형변화 탐지를 수행한 결과 침식과 퇴적의 최대값은 각각 2.56m와 2.24m로 나타났으며 평균적으로는 0.01m의 퇴적이 발생하였다. 그리고 2018. 6. 29 ~ 2019. 6. 14 동안의 침식과 퇴적의 최대값은 각각 2.31m와 2.28m로 나타났으며 평균값은 0.02m의 침식이 발생하였다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 침식과 퇴적의 최대값이 각각 2.28m와 2.55m로 나타났으며 평균값은 0.03m의 침식이 발생하였다. 지형변화를 보다 상세히 모니터링하고자 퇴적과 침식구간을 나누어 분석을 수행한 결과, 2018. 6. 29 ~ 2018. 12. 10 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 13,324.4m²와 14,667.3m²로 퇴적구간의 면적이 1,342.9m² 만큼 높게 나타났으며, 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,176.6m²와 11,723.0m²로 침식구간의 면적이 4,453m² 만큼 높게 나타났다. 또한 2018. 12. 10 ~ 2019. 6. 14 사이에는 0.5m 이내의 침식과 퇴적구간 면적이 각각 16,821.6m²와 11,126.4m²로 침식구간의 면적이 5,695.2m² 만큼 크게 분석되었다. 이와 같이 UAV 영상 기반의 연안지형 모니터링을 수행할 경우 시계열 지형변화를 효과적으로 모니터링할 수 있으며, 이러한 업무는 새만금 방조제 건설에 따른 지형변화의 영향평가 등 다양한 연안업무에 활용될 수 있을 것이다.

• 대한의용생체공학회:의공학회지
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• 제23권3호
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• pp.253-261
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• 2002

양전자방출단층촬영기(Positron emission tomography, PET) 영상 개선을 위하여 적응적 공간 필터를 개발하였으며. 개발한 필터의 성능을 시뮬레이션데이터. 모형 PET 영상과 환자 PET 영상을 이용하여 평가하였다. 경계화소로 검출된 화소와 윈도우내의 모든 화소값이 동일한 화소는 보존하고. 그 외 화소에 대하여 2:7:2 비율로 가중치를 주어 정열한 후 중앙의 9개 화소에 대한 평균값으로 대치하였다. 경계화소를 검출하기 위하여 두 개의 임계값(TH7, TH2)을 이용하였으며. 다음의 조건을 만족하면 경계화소로 판단하였다 . THl ($pix_max{\times}0.1/log_2(NPM)$, NPM :주변값중 최상위 값과 최하위 값을 제외한 주변값들의 평균) 보다 작은 ADs (중앙값과 주변값의 차에 대한 절대값) 개수는 8-k이고. TH2 ($NPM{\times}0.1$) 보다 큰 ADs 개수는 k. 여기서 k는 2, 3 ‥‥ 6의 값을 가진다 성능평가 결과 이 연구에서 제안한 필터가 가우시안 필터, 가중메디안 필터, 부분집합평균메디안 필터 등과 비교하여 우수한 성능을 제공하는 것을 관찰하였다. 본 논문에서 개발한 간단한 적응적 공간 필터는 공간 분해능 저하는 최소화하면서 균일도와 대조도를 향상시키는데 효과적 이여서 정확한 PET 영상 해석에 기여할 것으로 기대된다

• 한국게임학회 논문지
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• 제14권2호
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• pp.45-54
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• 2014

스마트폰의 발달로 게임 플랫폼이 확대되면서 <팩맨>, <스페이스인베이더>와 같은 고전게임이 스마트폰으로 이식되었다. 고전게임이 재조명되는 이런 현상은 게임뿐 아니라 영상미디어의 영역까지 확장되었는데, 이는 고전게임을 소재로 한다는 점에서 게이머들에게 이슈가 되었지만 게이머의 경험과는 다른 시선으로 전개되는 경우가 많아 아쉬움을 남겼다. 본고는 영상미디어에서 게이머의 경험을 재현하지 못하는 이유가 게임과 영상미디어 사이의 상호텍스트성에 있다고 보고, 잘 된 상호텍스트의 사례로써 를 분석하였다. 에 사용된 상호텍스트성을 분석한 결과 단순 표상 나열이나 패러디 외에 게이머만이 알 수 있는 요소들을 인용, 요약, 짜깁기, 풍자적 희화하여 게이머들의 경험을 재현하였고, 비게이머들에게도 종래에는 보지 못했던 신선한 연출로 대중성을 고려했음을 알 수 있었다.

• Macromolecular Research
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• 제17권2호
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• pp.99-103
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• 2009

We evaluated the efficacy of pH-sensitive micelles, formed by methoxy poly(ethylene glycol)-b-poly($\beta$)-amino ester) (PEG-PAE), as carriers for paclitaxel (PIX), a drug currently used to treat various cancers. PTX was successful encapsulated by a film hydration method. Micelles encapsulated more than 70% of the PTX and the size of the PTX-encapsulated micelles (PTX-PM) was less than 150 nm. In vitro experiments indicated that the micelles were unstable below pH 6.5. After encapsulation of PTX within the micelles, dynamic light scattering (DLS) studies indicated that low pH had a similar demicellization effect. An in vitro release study indicated that PTX was slowly released at pH 7.4 (normal body conditions) but rapidly released under weakly acidic conditions (pH 6.0). We demonstrated the safety of micelles from in vitro cytotoxicity tests on HeLa cells and the in vivo anti-tumor activity of PTX-PM in B16F 10 tumor-bearing mice. We concluded that these pH-sensitive micelles have potential as carriers for anti-cancer drugs.

• 한국건축시공학회지
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• 제19권3호
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• pp.239-246
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• 2019

국내 시설물의 노후화가 급속히 진행되고 있음에 따라 정부는 노후화 시설물의 안정성 검측과 유지관리에 대한 관심을 높이고 있다. 이에 본 연구는 대구광역시 서구 비산 4동/내당 2, 3동의 노후화 지역일대를 조사하고, 비행촬영을 통해 노후화 시설물에 대한 데이터를 획득하여 3D 지도를 구현하였다. 또한 3D 지도에 객관적/주관적 데이터를 추가적으로 기입함으로써 주민들이 쉽게 이해할 수 있으며, 관리자가 노후화 시설물에 대한 유지 보수 관리를 보다 수월하게 진행할 수 있는 4D 지도 생성 방안을 제시하였다.

• Restorative Dentistry and Endodontics
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• 제27권4호
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Journal of Astronomy and Space Sciences
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• 제35권3호
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• pp.201-210
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• 2018

The characterization of detectors installed in space- and ground-based instruments is important to evaluate the system performance. We report the development of a detector performance test system for astronomical applications using the Andor iKon M CCD camera. The performance test system consists of a light source, monochromator, integrating sphere, and power meters. We adopted the Czerny-Tuner monochromator with three ruled gratings and one mirror, which covers a spectral range of 200-9,000 nm with a spectral resolution of ~1 nm in the visible region. Various detector characteristics, such as the quantum efficiency, sensitivity, and noise, can be measured in wide wavelength ranges from the visible to mid-infrared regions. We evaluated the Korea Astronomy and Space Science Institute (KASI) detector performance test system by using the performance verification of the Andor iKon-M CCD camera. The test procedure includes measurements of the conversion gain ($2.86e^-/ADU$), full well capacity ($130K\;e^-$), nonlinearity, and pixel defects. We also estimated the read noise, dark current, and quantum efficiency as a function of the temperature. The lowest measured read noise is $12e^-$. The dark current at 223 K was determined to be $7e^-/s/pix$ and its doubling temperature is $5.3^{\circ}C{\pm}0.2^{\circ}C$ at an activation energy of 0.6 eV. The maximum quantum efficiency at 223 K was estimated to be $93%{\pm}2%$. We proved that the quantum efficiency is sensitive to the operating temperature. It varies up to 5 % in the visible region, while the variation increases to 30 % in the near-infrared region. Based on the comparison of our results with the test report by the vendor, we conclude that our performance test results are consistent with those from the vendor considering the test environment. We also confirmed that the KASI detector performance test system is reliable and our measurement method and analysis are accurate.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.352-352
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• 2017

Recently, the South Korean government encourages the cultivation of upland crops in the paddy field to maintain an adequate level of rice production and then to balance the demand and supply of rice. This is mainly because the rice consumption per capita per year has continued to decline from 135 kg in 1979 to 61.9 kg in 2016, although the rice production was relatively stable. As a result, the rice overproduction became a big social problem. As a part of that, various upland crops such as soybean, maize, minor cereals and forage crops are planted in the paddy field 10 years ago. The cultivation of these crops may settle the problem of short supply and mass import of the crops to some extent. However, a systematic remote observation of upland crops in the paddy field is very scarce. This study investigated the cultivation status of upland crops and any changes of crop harvesting in the paddy field by using an unmanned aerial vehicle (UAV). Also, we analyzed the kind of upland crops and cultivation area in the paddy field by utilizing time series observation images. A fixed wing UAV is used for the investigation. This is because it is easy to use the flight operation and to control flight management software, and it can automatically cope with various emergency states such as a strong wind and battery discharge. The material of UAV is expanded polypropylene, which has an advantage of less equipment damage and risk during takeoff and landing. We acquired observed images in Buljeong-myeon, Goesan-gun, Chungcheongbuk-do, South Korea by using fixed wing UAV in 2015 and 2016. The total investigated area reaches 6,045 ha, and among them the agricultural area was 1,377 ha. For the next step, we created an orthoimage from all images taken using Pix 4D mapper program. According to the results of image analyses in 2015, the paddy field covered total 577 ha (75.9%) with crop plant. The cultivation area of beans, ginseng, maize, tobacco and peach was 256 ha (36.6%), 63 ha (9.2%), 37 ha (5.4%), 31 ha (4.5%) and 27 ha (3.8), respectively. And in 2016, the total covered area was 586 ha (77.1%), and it was comprised of 253 ha (35.5%), 88 ha (12.3%), 29 ha (4.1%), 22 ha (3.1%) and 32 ha (4.5%) in the same order. In this study, we focused on identifying the paddy field which was converted to the cultivation of upland crops by using UAV. And, it has been indicated that the cultivation area of rice decreased from 141 ha in 2015 to 127 ha in 2016, although that of ginseng increased by 25 ha. As a result, it is expected that a lot of paddy field could be replaced by high-income crops such as ginseng and fruit tree (peach) instead of relative low-income rice. More specific and widespread research on the remote sensing in the paddy field needs to be done.

• Imaging Science in Dentistry
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• 제33권2호
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• pp.79-83
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• 2003

Purpose : To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. Materials and Methods: The study materials consisted of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix/sup (R)/ software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. Results: The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the indicating rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. Conclusion: Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.