• 제목/요약/키워드: high-res

검색결과 220건 처리시간 0.03초

Enhanced CT-image for Covid-19 classification using ResNet 50

  • Lobna M. Abouelmagd;Manal soubhy Ali Elbelkasy
    • International Journal of Computer Science & Network Security
    • /
    • 제24권1호
    • /
    • pp.119-126
    • /
    • 2024
  • Disease caused by the coronavirus (COVID-19) is sweeping the globe. There are numerous methods for identifying this disease using a chest imaging. Computerized Tomography (CT) chest scans are used in this study to detect COVID-19 disease using a pretrain Convolutional Neural Network (CNN) ResNet50. This model is based on image dataset taken from two hospitals and used to identify Covid-19 illnesses. The pre-train CNN (ResNet50) architecture was used for feature extraction, and then fully connected layers were used for classification, yielding 97%, 96%, 96%, 96% for accuracy, precision, recall, and F1-score, respectively. When combining the feature extraction techniques with the Back Propagation Neural Network (BPNN), it produced accuracy, precision, recall, and F1-scores of 92.5%, 83%, 92%, and 87.3%. In our suggested approach, we use a preprocessing phase to improve accuracy. The image was enhanced using the Contrast Limited Adaptive Histogram Equalization (CLAHE) algorithm, which was followed by cropping the image before feature extraction with ResNet50. Finally, a fully connected layer was added for classification, with results of 99.1%, 98.7%, 99%, 98.8% in terms of accuracy, precision, recall, and F1-score.

Attenuation of High-Frequency Wave Energy Due to Opposing Currents

  • Suh, Kyung-Duck;Lee, Dong-Young-
    • 한국해안해양공학회:학술대회논문집
    • /
    • 한국해안해양공학회 1993년도 정기학술강연회 발표논문 초록집
    • /
    • pp.20-25
    • /
    • 1993
  • In coastal waters, more often than not, waves propagate on currents driven by tidal forces, earth’s gravity, or wind. There have been a number of studies for dealing with the change of wave spectrum due to tile presence of current. Based on the conservation of wave action, Hedges et al. (1985) have proposed an equation which describes the influence of current on the change of wave spectrum in water of finite depth. (omitted)

  • PDF

Screening of Exiguobacterium acetylicum from Soil Samples Showing Enantioselective and Alkalotolerant Esterase Activity

  • Hwang Bum-Yeol;Kim Ji-Hyun;Kim Juhan;Kim Byung-Gee
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • 제10권4호
    • /
    • pp.367-371
    • /
    • 2005
  • About 3,000 bacterial colonies with esterase activities were isolated from soil samples by enrichment culture and halo-size on Luria broth-tributyrin (LT) plates. The colonies were assayed for esterase activity in microtiter plates using enantiomerically pure (R)- and (S)-2-phenylbutyric acid resorufin ester (2PB-O-res) as substrates. Two enantioselective strains (JH2 and JH13) were selected by the ratio of initial rate of hydrolysis of enantiomerically pure (R)- and (S)-2-PB-O-res. When cell pellets were used, both strains showed high apparent enantioselectivity ($E_{app}>100$) for (R)-2PB-O-res and were identified as Exiguobacterium acetylicum. The JH13 strain showed high esterase activity on p-nitrophenyl acetate (pNPA), but showed low lipase activity on p-nitrophenyl palmitate (pNPP). The esterase was located in the soluble fraction of the cell extract. The crude intracellular enzyme preparation was stable at a pH range from 6.0 to 11.0.

합성곱 신경망을 이용한 정사사진 기반 균열 탐지 기법 (Crack Detection Technology Based on Ortho-image Using Convolutional Neural Network)

  • 장아름;정상기;박진한;강창훈;주영규
    • 한국공간구조학회논문집
    • /
    • 제22권2호
    • /
    • pp.19-27
    • /
    • 2022
  • Visual inspection methods have limitations, such as reflecting the subjective opinions of workers. Moreover, additional equipment is required when inspecting the high-rise buildings because the height is limited during the inspection. Various methods have been studied to detect concrete cracks due to the disadvantage of existing visual inspection. In this study, a crack detection technology was proposed, and the technology was objectively and accurately through AI. In this study, an efficient method was proposed that automatically detects concrete cracks by using a Convolutional Neural Network(CNN) with the Orthomosaic image, modeled with the help of UAV. The concrete cracks were predicted by three different CNN models: AlexNet, ResNet50, and ResNeXt. The models were verified by accuracy, recall, and F1 Score. The ResNeXt model had the high performance among the three models. Also, this study confirmed the reliability of the model designed by applying it to the experiment.

Two-phase flow pattern online monitoring system based on convolutional neural network and transfer learning

  • Hong Xu;Tao Tang
    • Nuclear Engineering and Technology
    • /
    • 제54권12호
    • /
    • pp.4751-4758
    • /
    • 2022
  • Two-phase flow may almost exist in every branch of the energy industry. For the corresponding engineering design, it is very essential and crucial to monitor flow patterns and their transitions accurately. With the high-speed development and success of deep learning based on convolutional neural network (CNN), the study of flow pattern identification recently almost focused on this methodology. Additionally, the photographing technique has attractive implementation features as well, since it is normally considerably less expensive than other techniques. The development of such a two-phase flow pattern online monitoring system is the objective of this work, which seldom studied before. The ongoing preliminary engineering design (including hardware and software) of the system are introduced. The flow pattern identification method based on CNNs and transfer learning was discussed in detail. Several potential CNN candidates such as ALexNet, VggNet16 and ResNets were introduced and compared with each other based on a flow pattern dataset. According to the results, ResNet50 is the most promising CNN network for the system owing to its high precision, fast classification and strong robustness. This work can be a reference for the online monitoring system design in the energy system.

SegNet과 ResNet을 조합한 딥러닝에 기반한 횡단보도 영역 검출 (Detection of Zebra-crossing Areas Based on Deep Learning with Combination of SegNet and ResNet)

  • 량한;서수영
    • 한국측량학회지
    • /
    • 제39권3호
    • /
    • pp.141-148
    • /
    • 2021
  • 본 논문은 SegNet과 ResNet을 조합한 딥러닝을 이용하여 횡단보도를 검출하는 방법을 제안한다. 시각 장애인의 경우 횡단보도가 어디에 있는지 정확히 아는 게 안전한 교통 시스템에서 중요하다. 딥러닝에 의한 횡단보도 검출은 이 문제에 대한 좋은 해결책이 될 수 있다. 로봇 시각 기반 보조 기술은 지난 몇년 동안 카메라를 사용하는 특정 장면에 초점을 두고 제안되어 왔다. 이러한 전통적인 방법은 비교적 긴 처리 시간으로 의미있는 결과를 얻었으며 횡단보도 인식을 크게 향상시켰다. 그러나 전통적인 방법은 지연 시간이 길고 웨어러블 장비에서 실시간을 만족시킬 수 없다. 본 연구에서 제안하는 방법은 취득한 영상에서 횡단보도를 빠르고 안정적으로 검출하기 위한 모델을 제안한다. 모델은 SegNet과 ResNet을 기반으로 개선되었으며 3단계로 구성된다. 첫째, 입력 영상을 서브샘플링하여 이미지 특징을 추출하고 ResNet의 컨벌루션 신경망을 수정하여 새로운 인코더로 만든다. 둘째, 디코딩 과정에서 업샘플링 네트워크를 통해 특징맵을 원영상 크기로 복원한다. 셋째, 모든 픽셀을 분류하고 각 픽셀의 정확도를 계산한다. 이 실험의 결과를 통하여 수정된 시맨틱 분할 알고리즘의 적격한 정확성을 검증하는 동시에 결과 출력 속도가 비교적 빠른 것으로 파악되었다.

추대가 늦고 진적색인 적축면 상추 "미홍" 육성 (Late bolting and Deep Red Leaf Lettuce "Mihong")

  • 장석우;허운영;최미자;권영석;김점순;이종남;이응호;서명훈;박재호;장익;장미향;황해준;고순보
    • 한국육종학회지
    • /
    • 제41권4호
    • /
    • pp.579-582
    • /
    • 2009
  • "미홍"은 "단홍적축면"과 "뚝섬적축면"을 교배하여 육성한 추대가 늦고, 엽색이 매우진한 적축면 잎상추 품종이다. 기존 같은 type의 품종보다 추대가 늦은 중만생 품종이며, 적색발현이 좋아, 안토시안닌 함량이 28.9 mg/100 g으로 "뚝섬적축면"보다 10배이상 많았으며 수확 후 $4^{\circ}C$에서 3주간 이상 저장이 가능하였다. 재배적기는 연중재배가 가능하나 시험재배 결과 평난지에서는 봄, 가을에 고랭지에서는 여름재배가 가능하며, 노지 및 비가림하우스 등 어느 곳에서나 재배가 가능한 품종이다. 수확 가능한 엽수는 주당 54매이며, 주중은 291 g으로 상품수량성은 17.0 ton/ha로 "뚝섬적축면"보다 2% 증수되었다.

Comparative Studies on Velvet Deer Antler and Ossified Deer Antler on the Contents of Bioactive Components and on the Bone Mineral Density Improving Activity for Oophorectomized Rat

  • Jo, Sung Jun;Kim, Jung Hwan;Kim, Jeung-Won;Choi, Hye Ok;Lee, Seung Hwan;Kim, Mu-Kang;Woo, Sun Hee;Han, Byung Hoon
    • Natural Product Sciences
    • /
    • 제19권4호
    • /
    • pp.303-310
    • /
    • 2013
  • Velvet deer antler (VDA) is well known oriental medicine claimed to have tonic activities as improving bone mineral density (BMD), immune-enhancing, rejuvenating and many other medicinal activities. Ossified deer antler (ODA) is bony product produced by over-calcification of deer antler due to late harvesting. The extraction efficiency of ODA by conventional boiling in water must be very poor due to bony nature, hence the reputations for the medicinal efficacies of ODA has been highly under-evaluated compared to that of VDA without any experimental evidences. Employing our new efficient water extraction process ($135^{\circ}C$), the extracts of ODA and VDA were analysed to compare the contents of bioactive components and the potencies of pharmacological activities. The results showed that; 1) The $135^{\circ}C$ extraction (autoclaving) of ODA gave highly increased amount of biomass, 120% more than the conventional extraction by 100-boiling, whereas the same treatment for VDA showed only 15% increased amount of biomass. 2) Feeding the ODA- or VDA-extracts to oophorectomized rats showed very potent BMD-recovering activity. 3) During the ossification of deer antler, the total collagen content was found to be increased by addition of type-1 to pre-existing type-2 collagen, but not replacement of type-2 to type-1 collagen. High titer of peptide hormones like growth hormone and IGF-1 were detected in the ODA- and VDA-extracts and also in the serum of ODA- or VDA-treated oophorectomized animals dose-dependently. Present experimental data will give a conclusion that folkloric poor reputations on ODA must be concerned only with poor extraction efficiency of conventional $100^{\circ}C$ water extraction and not based on the composition of bioactive substances of ODA.

Ca2+ Sensitivity of Anoctamin 6/TMEM16F Is Regulated by the Putative Ca2+-Binding Reservoir at the N-Terminal Domain

  • Roh, Jae Won;Hwang, Ga Eun;Kim, Woo Kyung;Nam, Joo Hyun
    • Molecules and Cells
    • /
    • 제44권2호
    • /
    • pp.88-100
    • /
    • 2021
  • Anoctamin 6/TMEM16F (ANO6) is a dual-function protein with Ca2+-activated ion channel and Ca2+-activated phospholipid scramblase activities, requiring a high intracellular Ca2+ concentration (e.g., half-maximal effective Ca2+ concentration [EC50] of [Ca2+]i > 10 μM), and strong and sustained depolarization above 0 mV. Structural comparison with Anoctamin 1/TMEM16A (ANO1), a canonical Ca2+-activated chloride channel exhibiting higher Ca2+ sensitivity (EC50 of 1 μM) than ANO6, suggested that a homologous Ca2+-transferring site in the N-terminal domain (Nt) might be responsible for the differential Ca2+ sensitivity and kinetics of activation between ANO6 and ANO1. To elucidate the role of the putative Ca2+-transferring reservoir in the Nt (Nt-CaRes), we constructed an ANO6-1-6 chimera in which Nt-CaRes was replaced with the corresponding domain of ANO1. ANO6-1-6 showed higher sensitivity to Ca2+ than ANO6. However, neither the speed of activation nor the voltage-dependence differed between ANO6 and ANO6-1-6. Molecular dynamics simulation revealed a reduced Ca2+ interaction with Nt-CaRes in ANO6 than ANO6-1-6. Moreover, mutations on potentially Ca2+-interacting acidic amino acids in ANO6 Nt-CaRes resulted in reduced Ca2+ sensitivity, implying direct interactions of Ca2+ with these residues. Based on these results, we cautiously suggest that the net charge of Nt-CaRes is responsible for the difference in Ca2+ sensitivity between ANO1 and ANO6.