• 한국차세대컴퓨팅학회논문지
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• 제13권3호
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• pp.26-33
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• 2017

최근 클라우드 플랫폼을 효율적으로 사용하기 위한 컨테이너 기술들이 주목을 받고 있다. 컨테이너 가상화 기술은 기존 하이퍼바이저와 비교하였을 때 이식성이 뛰어나고 집적도가 높다는 장점을 가지고 있다. 하지만 컨테이너 가상화 기술은 하나의 커널을 공유하여 복수개의 인스턴스를 구동하는 운영체제 레벨의 가상화 기술을 사용하기 때문에 인스턴스 간 공유 자원 요소가 많아져 취약성 또한 증가하는 보안 문제를 가지고 있다. 컨테이너는 컴퓨팅 자원의 효율적 운용을 위해 호스트 운영체제의 라이브러리를 공유하는 특성으로 인해 공격자는 커널의 취약점을 이용하여 호스트 운영체제의 루트 권한 획득 공격이 가능하다. 본 논문에서는 컨테이너가 사용하는 특정 메모리 영역의 변화를 감지하고, 감지 시에는 해당 컨테이너의 동작을 중지시키는 메모리 트랩 기법을 사용하여 컨테이너 내부에서 발생되는 호스트 운영체제의 루트 권한 탈취 공격을 효율적으로 탐지 및 대응하기 위한 프레임워크를 제안한다.

• Journal of Animal Science and Technology
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• 제65권3호
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• pp.638-651
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• 2023

The objective of this study was to quantitatively estimate the level of grazing area damage in outdoor free-range pig production using a Unmanned Aerial Vehicles (UAV) with an RGB image sensor. Ten corn field images were captured by a UAV over approximately two weeks, during which gestating sows were allowed to graze freely on the corn field measuring 100 × 50 m². The images were corrected to a bird's-eye view, and then divided into 32 segments and sequentially inputted into the YOLOv4 detector to detect the corn images according to their condition. The 43 raw training images selected randomly out of 320 segmented images were flipped to create 86 images, and then these images were further augmented by rotating them in 5-degree increments to create a total of 6,192 images. The increased 6,192 images are further augmented by applying three random color transformations to each image, resulting in 24,768 datasets. The occupancy rate of corn in the field was estimated efficiently using You Only Look Once (YOLO). As of the first day of observation (day 2), it was evident that almost all the corn had disappeared by the ninth day. When grazing 20 sows in a 50 × 100 m² cornfield (250 m²/sow), it appears that the animals should be rotated to other grazing areas to protect the cover crop after at least five days. In agricultural technology, most of the research using machine and deep learning is related to the detection of fruits and pests, and research on other application fields is needed. In addition, large-scale image data collected by experts in the field are required as training data to apply deep learning. If the data required for deep learning is insufficient, a large number of data augmentation is required.

• 한국건축시공학회지
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• 제23권4호
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• pp.441-452
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• 2023

장기방치된 공사중단 건축물들은 외기의 노출로 인한 철근의 녹 발생, 콘크리트의 품질 저하 등으로 건축물의 내구성이 심각하게 저하될 수 있으며, 관리부실로 안전사고, 사회적 범죄 발생, 환경오염 등 공사중단 건축물에 대한 심각성이 커지고 있다. 본 연구는 제주 지역의 공사중단 건축물의 현황을 조사하고 문제점을 파악하고, 1곳에 대해 구조체의 내구성을 조사분석하여 사용가능성을 진단하였다. 내구성 조사를 위해 외관조사(육안조사, 기울기조사)와 비파괴검사(압축강도시험, 탄산화조사시험, 철근탐사시험)이 진행되었으며, 구조체가 내구성을 갖추고 있으며 건축물의 상태는 경과년수에 비하여 양호한 것으로 분석되었다.

• Journal of Radiation Protection and Research
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• 제47권4호
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• pp.214-225
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• 2022

Background: The conventional cerium-doped Gd₂Al₂Ga₃O₁₂ (GAGG(Ce)) scintillator-based gamma-ray imager has a bulky detector, which can lead to incorrect positioning of the gammaray source if the shielding against background radiation is not appropriately designed. In addition, portability is important in complex environments such as inside nuclear power plants, yet existing gamma-ray imager based on a tungsten mask tends to be weighty and therefore difficult to handle. Motivated by the need to develop a system that is not sensitive to background radiation and is portable, we changed the material of the scintillator and the coded aperture. Materials and Methods: The existing GAGG(Ce) was replaced with Bi₄Ge₃O₁₂ (BGO), a scintillator with high gamma-ray detection efficiency but low energy resolution, and replaced the tungsten (W) used in the existing coded aperture with lead (Pb). Each BGO scintillator is pixelated with 144 elements (12 × 12), and each pixel has an area of 4 mm × 4 mm and the scintillator thickness ranges from 5 to 20 mm (5, 10, and 20 mm). A coded aperture consisting of Pb with a thickness of 20 mm was applied to the BGO scintillators of all thicknesses. Results and Discussion: Spectroscopic characterization, imaging performance, and image quality evaluation revealed the 10 mm-thick BGO scintillators enabled the portable gamma-ray imager to deliver optimal performance. Although its performance is slightly inferior to that of existing GAGG(Ce)-based gamma-ray imager, the results confirmed that the manufacturing cost and the system's overall weight can be reduced. Conclusion: Despite the spectral characteristics, imaging system performance, and image quality is slightly lower than that of GAGG(Ce), the results show that BGO scintillators are preferable for gamma-ray imaging systems in terms of cost and ease of deployment, and the proposed design is well worth applying to systems intended for use in areas that do not require high precision.

• 대한토목학회논문집
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• 제26권3D호
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• pp.519-525
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• 2006

기존의 영역기반의 영상정합이나 에피폴라 기하 혹은 고도값 제한 등을 통해 정합의 탐색영역을 줄임으로 영상정합의 효율성을 높이는 방법들은 비슷한 형태의 고층 건물이 밀집되어 있는 대규모 도심지와 같은 경우 오정합의 가능성이 크며 정합에 소요되는 시간도 여전히 오래 걸리는 단점을 갖고 있다. 이러한 단점을 보완하기 위하여 건물 인식을 통한 영상정합법에 대하여 연구를 수행하고자 한다. 본 논문에서는 새로운 영상정합기법의 기초연구로서 컬러영상으로부터 경계정보와 색상 정보를 활용하여 동일 건물 인식에 관하여 실험을 수행하였다. 경계정보와 색상정보를 활용하기 위하여 각각 보완된 Hausdorff 거리개념과 보완된 컬러 인덱싱 기법을 적용하였다. 각각의 정보를 단독으로 활용한 경우 동일건물의 인식률이 경계정보의 경우 46.5%, 색상정보의 경우 7.1%로 매우 낮았으나, 두 가지 정보를 조합하여 인식을 실시한 결과 78.5%로 인식률이 높아지는 것을 확인할 수 있었다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.2-5
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• 2022

사람의 체내 장기는 복잡한 구조로 되어있으며 특히, 소장은 길이가 약 7m 길이를 가지고 있어 내시경 검사가 쉽지 않고 내시경 검사 시 위험도가 높다. 현재는 캡슐 내시경으로 검사를 수행하고 있으며, 검사 시간이 매우 긴 편이다. 의사는 제거된 저장장치를 컴퓨터에 연결해 환자의 캡슐 내시경 영상을 저장 후 프로그램을 사용하여 판독하지만, 캡슐 내시경 검사 결과 영상 길이가 길어 판독 시간이 많이 소요된다. 또한 소장의 경우 융모에 의해 많은 굴곡이 존재해 검사 과정에서 영상의 폐색 영역이나 명암이 뚜렷이 나타나게 되어 검사 시 병변 및 이상징후에 관해 놓치는 경우가 발생할 수 있다. 본 논문에서는 의사의 영상 판독 시간 단축과 진단 신뢰도 향상을 위해 인공신경망을 이용한 소장 캡슐 내시경 병변 검사 보조 방법을 제공한다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.75-75
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• 2022

Traditional agriculture mostly focused on activity in the field, but current agriculture faces problems such as reduction of agricultural inputs, labor shortage and so on. Accordingly, traditional agricultural experiments generally considered the simple treatment effects, but current agricultural experiments need to consider the several and complicate treatment effects. To analyze such several and complicate treatment effects, data collection has the first priority. Remote sensing is a quite effective tool to collect information in agriculture, and recent easier availability of UAVs (Unmanned Aerial Vehicles) enhances the effectiveness. LAI (Leaf Area Index) is one of the most important information for evaluating the condition of crop growth. In this study, we utilized UAV with multispectral camera to evaluate plant-based LAI of sweetcorn in a small-scale field experiment and discussed the feasibility of a new experimental design to analyze the several and complicate treatment effects. The plant-based SR measured by UAV showed the highest correlation coefficient with LAI measured by a canopy analyzer in 2018 and 2019. Application of linear mix model showed that plant-based SR data had higher detection power due to its huge number of data although SR was inferior to evaluate LAI than the canopy analyzer. The distribution of plant-based data also statistically revealed the border effect in treatment plots in the traditional experimental design. These results suggest that remote sensing with UAVs has the advantage even in a small-scale experimental plot and has a possibility to provide a new experimental design if combined with various analytical applications such as plant size, shape, and color.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.88-88
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• 2022

Detection of stress responses in crops is important to diagnose crop growth and evaluate yield. Also, the multi-spectral sensor is effectively known to evaluate stress caused by nutrient and moisture in crops or biological agents such as weeds or diseases. Therefore, in this experiment, multispectral images were taken by an unmanned aerial vehicle(UAV) under field condition. The experiment was conducted in the long-term fertilizer field in the National Institute of Crop Science, and experiment area was divided into different status of NPK(Control, N-deficiency, P-deficiency, K-deficiency, Non-fertilizer). Total 11 vegetation indices were created with RGB and NIR reflectance values using python. Variations in nutrient content in plants affect the amount of light reflected or absorbed for each wavelength band. Therefore, the objective of this experiment was to evaluate vegetation indices derived from multispectral reflectance data as input into machine learning algorithm for the classification of nutritional deficiency in rice. RandomForest model was used as a representative ensemble model, and parameters were adjusted through hyperparameter tuning such as RandomSearchCV. As a result, training accuracy was 0.95 and test accuracy was 0.80, and IPCA, NDRE, and EVI were included in the top three indices for feature importance. Also, precision, recall, and f1-score, which are indicators for evaluating the performance of the classification model, showed a distribution of 0.7-0.9 for each class.

• Journal of Veterinary Science
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• 제24권5호
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• pp.54.1-54.13
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• 2023

Background: Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines do not provide full cross-protection, mainly due to the virus genetic variability. Despite this, vaccines based on modified-live PRRSV (PRRSV-MLV) reduce the disease impact. Objectives: To assess the efficacy of two commercial vaccines-one based on PRRSV1 (PRRSV1-MLV) and another on PRRSV2 (PRRSV2-MLV)-against a Japanese PRRSV2 field strain. Methods: Two groups of three-week-old piglets were vaccinated (G1: PRRSV1-MLV; G2: PRRSV2-MLV) and two were kept as non-vaccinated (INF and CTRL). One month later, G1, G2, and INF were challenged with a PRRSV2 field strain. Results: After the challenge, clinical signs were only observed in INF. Moreover, the highest rectal temperatures and values for the area under the curve (AUC) were observed in INF. Regarding viral detection, both AUC and the proportion of positive samples in blood were higher in INF. In G1, viremic animals never reached 100%. At necropsy (21 d after the challenge), differences for titers among groups were only found in tonsils (G1 < G2 and INF). One animal (belonging to G1) was negative in all tissues. Regarding humoral responses, G1 and G2 seroconverted after vaccination, as detected in the corresponding enzyme-linked immunosorbent assay. Specific neutralizing antibodies (NA) against PRRSV1-MLV were already detected at 14 d after vaccination in G1, showing a significant booster after the challenge, while PRRSV2-MLV NA were detected in G2 at the end of the experiment. Conclusions: Despite genetic differences, PRRSV1-MLV has been demonstrated to confer partial protection against a Japanese PRRSV2 strain, at least as good as PRRSV2-MLV.

• Journal of Oral Medicine and Pain
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• 제48권3호
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• pp.81-86
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• 2023

Purpose: To evaluate the clinical and radiologic findings of the postoperative maxillary cysts (POMCs) and investigate the relationship between lesion size and clinical symptoms depending on the time elapsed after radical maxillary sinus surgery. Methods: A total of 29 patients who were diagnosed with POMCs at Chonnam National University Dental Hospital were selected. Clinical and radiologic findings were investigated. POMC cases were divided into two groups: those with <24 years between maxillary sinus surgery and POMC diagnosis and those with >24 years. The chi-square test was used to compare the differences between the two groups. Results: The average period from surgery to POMC detection was 24.32 years; however, the period could not be confirmed in four patients. The average patient age was 52.75 years, and 12 (41.3%) patients were in their 50s. POMC-related clinical symptoms were as follows: buccal pain and swelling, dull pain, toothache, abscess, sensory abnormality, and asymptomatic. Twenty (69.0%) cases showed unilocular radiolucency and 9 (31.0%) revealed multilocular radiolucency. Seven cases (35.0%) were misdiagnosed as odontogenic lesions, resulting in the delayed treatment of POMCs. No statistical significance was found between the two groups with respect to symptoms, expansion to the surrounding area, presence of secondary cysts, and mesiodistal length of cyst on cone-beam computed tomography (CBCT) images. However, the buccopalatal length of the cyst on CBCT images was significantly different between the two groups. Conclusions: The buccopalatal length of POMCs observed on CBCT images was related to the time elapsed since surgery. The lack of awareness of POMCs may lead to misdiagnosis as an odontogenic infection and delayed treatment. Therefore, dentists must recognize the clinical and radiologic features of POMCs to differentiate it from dental infections.