• Title/Summary/Keyword: Image technique

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The Vectra M3 3-dimensional digital stereophotogrammetry system: A reliable technique for detecting chin asymmetry

  • Hansson, Stina;Ostlund, Emil;Bazargani, Farhan
    • Imaging Science in Dentistry
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    • v.52 no.1
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    • pp.43-51
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    • 2022
  • Purpose: The aim of this study was to evaluate the reliability of the Vectra M3 (3D Imaging System; Canfield Scientific, Parsippany, NJ, USA) in detecting chin asymmetry, and to assess whether the automatic markerless tracking function is reliable compared to manually plotting landmarks. Materials and Methods: Twenty subjects (18 females and 2 males) with a mean age of 42.5±10.5 years were included. Three-dimensional image acquisition was carried out on all subjects with simulated chin deviation in 4 stages (1-4 mm). The images were analyzed by 2 independent observers through manually plotting landmarks and by Vectra software auto-tracking mode. Repeated-measures analysis of variance and the Tukey post-hoc test were performed to evaluate the differences in mean measurements between the 2 operators and the software for measuring chin deviation in 4 stages. The intraclass correlation coefficient (ICC) was calculated to estimate the intra- and inter-examiner reliability. Results: No significant difference was found between the accuracy of manually plotting landmarks between observers 1 and 2 and the auto-tracking mode (P=0.783 and P=0.999, respectively). The mean difference in detecting the degree of deviation according to the stage was <0.5 mm for all landmarks. Conclusion: The auto-tracking mode could be considered as reliable as manually plotted landmarks in detecting small chin deviations with the Vectra® M3. The effect on the soft tissue when constructing a known dental movement yielded a small overestimation of the soft tissue movement compared to the dental movement (mean value<0.5 mm), which can be considered clinically non-significant.

A Study on the GK2A/AMI Image Based Cold Water Detection Using Convolutional Neural Network (합성곱신경망을 활용한 천리안위성 2A호 영상 기반의 동해안 냉수대 감지 연구)

  • Park, Sung-Hwan;Kim, Dae-Sun;Kwon, Jae-Il
    • Korean Journal of Remote Sensing
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    • v.38 no.6_2
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    • pp.1653-1661
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    • 2022
  • In this study, the classification of cold water and normal water based on Geo-Kompsat 2A images was performed. Daily mean surface temperature products provided by the National Meteorological Satellite Center (NMSC) were used, and convolution neural network (CNN) deep learning technique was applied as a classification algorithm. From 2019 to 2022, the cold water occurrence data provided by the National Institute of Fisheries Science (NIFS) were used as the cold water class. As a result of learning, the probability of detection was 82.5% and the false alarm ratio was 54.4%. Through misclassification analysis, it was confirmed that cloud area should be considered and accurate learning data should be considered in the future.

Feasibility of Optical Character Recognition (OCR) for Non-native Turtle Detection (UAV 기반 외래거북 탐지를 위한 광학문자 인식(OCR)의 가능성 평가)

  • Lim, Tai-Yang;Kim, Ji-Yoon;Kim, Whee-Moon;Kang, Wan-Mo;Song, Won-Kyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.25 no.5
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    • pp.29-41
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    • 2022
  • Alien species cause problems in various ecosystems, reduce biodiversity, and destroy ecosystems. Due to these problems, the problem of a management plan is increasing, and it is difficult to accurately identify each individual and calculate the number of individuals, especially when researching alien turtle species such as GPS and PIT based on capture. this study intends to conduct an individual recognition study using a UAV. Recently, UAVs can take various sensor-based photos and easily obtain high-definition image data at low altitudes. Therefore, based on previous studies, this study investigated five variables to be considered in UAV flights and produced a test paper using them. OCR was used to monitor the displayed turtles using the manufactured test paper, and this confirmed the recognition rate. As a result, the use of yellow numbers showed the highest recognition rate. In addition, the minimum threat distance was confirmed to be 3 to 6m, and turtles with a shell size of 6 to 8cm were also identified during the flight. Therefore, we tried to propose an object recognition methodology for turtle display text using OCR, and it is expected to be used as a new turtle monitoring technique.

Smoke Rendering Method in Post-processing for Safety-Training Contents (안전 훈련 콘텐츠에 적합한 포스트 프로세싱 단계에서의 연기 렌더링 방법)

  • Park, Sanghyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.26 no.11
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    • pp.1644-1652
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    • 2022
  • In the case of safety training where practical training is impossible due to risk problems, training contents using realistic media such as virtual reality or augmented reality are becoming a new alternative. In this paper, we propose a smoke modeling method that can be applied to safety-training contents implemented with realistic media technology. When an accident occurs in a hazardous area such as a petrochemical plant, visibility is not secured due to gas leakage and fire. In order to create such a situation, it is important to realistically express smoke. The proposed method is a smoke model implementation technique that can be effectively applied to the background of complex passages and devices such as petrochemical plants. In the proposed method, the smoke is expressed using volumetric rendering in the post-processing stage for the resulting image of scene rendering. Implementation results in the background of the factory show that the proposed method produces models that can express the smoke realistically.

Synthesis and radiolabeling of PEGylated dendrimer-G2-Gemifloxacin with 99mTc to Biodistribution study in rabbit

  • Mohtavinejad, Naser;Dolatshahi, Shaya;Amanlou, Massoud;Ardestani, Mehdi Shafiee;Asadi, Mehdi;Pormohammad, Ali
    • Advances in nano research
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    • v.10 no.5
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    • pp.461-470
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    • 2021
  • Infection is one of the major mortality causes throughout the globe. Nuclear medicine plays an important role in diagnosis of deep infections such as osteomyelitis, arthritis infection, heart valve and heart prosthesis infections. Techniques such as labeled leukocytes are sensitive and selective for tracking the inflammations but they are not suitable for differentiating infection from inflammation. Anionic linear-globular dendrimer-G2 was synthesized then conjugation to gemifloxacin antibiotic. The structures were identified by FT-IR, 1H-NMR, C-NMR, LC-MS and DLS. The toxicity of gemifloxacin and dendrimer-gemifloxacin complex was compared by MTT test. Dendrimer-G2-gemifloxacin was labeled by Technetium-99m and its in-vitro stability and radiochemical purity were investigated. In-vivo biodistribution and SPECT imaging were studied in a rabbit model. Identify and verify the structure of the each object was confirmed by FT-IR, 1H-NMR, C-NMR and LC-MS, also, the size and charge of this compound were 128 nm and -3/68 mv respectively. MTT test showed less toxicity of the dendrimer-G2-gemifloxacin than free gemifluxacin (P < 0.001). Radiochemical yield was > %98. Human serum stability was 84% up to 24 h. Biodistribution study at 50 min, 24 and 48 h showed that the complex is significantly absorbed by the intestine and accumulation in the lungs and affects them, finally excreted through the kidneys, biodistribution results are consistent with results from full image means of SPECT/CT technique.

Deep Learning-based Pes Planus Classification Model Using Transfer Learning

  • Kim, Yeonho;Kim, Namgyu
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.4
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    • pp.21-28
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    • 2021
  • This study proposes a deep learning-based flat foot classification methodology using transfer learning. We used a transfer learning with VGG16 pre-trained model and a data augmentation technique to generate a model with high predictive accuracy from a total of 176 image data consisting of 88 flat feet and 88 normal feet. To evaluate the performance of the proposed model, we performed an experiment comparing the prediction accuracy of the basic CNN-based model and the prediction model derived through the proposed methodology. In the case of the basic CNN model, the training accuracy was 77.27%, the validation accuracy was 61.36%, and the test accuracy was 59.09%. Meanwhile, in the case of our proposed model, the training accuracy was 94.32%, the validation accuracy was 86.36%, and the test accuracy was 84.09%, indicating that the accuracy of our model was significantly higher than that of the basic CNN model.

Increase of CO2 Injection Ratio Using Surfactants Based on the Micromodel Experiment (마이크로모델 실험 기반 계면활성제를 활용한 이산화탄소 주입효율 향상)

  • Seokgu, Gang;Jongwon, Jung
    • Journal of the Korean GEO-environmental Society
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    • v.23 no.12
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    • pp.55-61
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    • 2022
  • Carbon dioxide is one of the greenhouse gases in the atmosphere and much research is underperforming in reducing carbon dioxide. Geological carbon dioxide storage is considered the primary technique for global warming prevention. So, technic development for storing carbon dioxide is required. Using surfactant is considered an effective material for geological carbon dioxide storage. However, research on using surfactants for carbon dioxide sequestration is not enough. In this study, a 2D micromodel experiment depends on the surfactant type (sodium dodecyl sulfate and sodium dodecylbenzene sulfonate), concentration and carbon dioxide injection rate. As result, geological carbon dioxide sequestration efficiency is increased according to surfactant concentration and carbon dioxide injection rate increase. However, efficiency no more increases after critical concentration and rate.

Spray Characteristics of Additive Manufactured Swirl Coaxial Injectors with Different Recess Lengths (적층제조 와류동축형 분사기 리세스 길이에 따른 분무특성)

  • Ahn, Jonghyeon;Lim, Ha Young;Ahn, Kyubok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.26 no.1
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    • pp.47-59
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    • 2022
  • Four swirl coaxial injectors with different recess lengths were manufactured using an additive manufacturing method. Single-injection and bi-injection cold-flow experiments were performed using water and air as simulated propellants in an atmospheric pressure environment. According to the recess length and propellant flow conditions, the injection pressure drop and discharge coefficient were investigated, and the breakup length and spray angle were measured using an image processing technique. In the bi-injection pressure drop and discharge coefficient results, the liquid-side injector was not affected by the recess. For the gas-side injector, however, the injection pressure drop increased and the discharge coefficient decreased as the recess length increased. The breakup length in the single-injection increased with the increase of the recess, but decreased in the bi-injection.

Selective Shuffling for Hiding Hangul Messages in Steganography (스테가노그래피에서 한글 메시지 은닉을 위한 선택적 셔플링)

  • Ji, Seon-su
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.3
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    • pp.211-216
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    • 2022
  • Steganography technology protects the existence of hidden information by embedding a secret message in a specific location on the cover medium. Security and resistance are strengthened by applying various hybrid methods based on encryption and steganography. In particular, techniques to increase chaos and randomness are needed to improve security. In fact, the case where the shuffling method is applied based on the discrete cosine transform(DCT) and the least significant bit(LSB) is an area that needs to be studied. I propose a new approach to hide the bit information of Hangul messages by integrating the selective shuffling method that can add the complexity of message hiding and applying the spatial domain technique to steganography. Inverse shuffling is applied when extracting messages. In this paper, the Hangul message to be inserted is decomposed into the choseong, jungseong and jongseong. It improves security and chaos by applying a selective shuffling process based on the corresponding information. The correlation coefficient and PSNR were used to confirm the performance of the proposed method. It was confirmed that the PSNR value of the proposed method was appropriate when compared with the reference value.

A Study on the Formative Characteristics of Vyshyvanka Embroidery Expressed in Apparel Elements (의복구성요소에 표현된 비쉬반카 자수의 조형적 특성 연구)

  • Song, A-ra;Lee, Jin-Hee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.24 no.1
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    • pp.59-69
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    • 2022
  • Vyshyvanka, the embroidered folk costume shirt of Ukraine, originated during the early reign of the Slavs, and currently, it is also called Ukrainian embroidery. In cases of Vyshyvanka embroidery expressed in apparel elements, it is necessary to research formative characteristics for expanding the visual aspect through the diversification of techniques, but also the aspect of the psychological meaning to Ukrainians. This study aims to consider Vyshyvanka as a unique embroidery technique, and also analyze the formative characteristics expressed in apparel elements. The study of Vyshyvanka embroidery expressed in apparel elements can present meaning to understanding the Ukrainian fashion. The image materials for the analysis of Vyshyvanka design, included work photos contained in literary materials and foreign online visual materials. The results of formatively analyzing the Vyshyvanka embroidery expressed in apparel are as follows. First, the Vyshyvanka embroidery expressed in apparel elements held an incantatory meaning, protecting wearers from getting easily invaded by evil spirits. Second, the Vyshyvanka patterns utilized symbolism that implied the incantatory meaning. Third, a single color was used for the embroidery. Lastly, materials like cotton, that are easy to embroider, were mostly used. The formative characteristics of Vyshyvanka embroidery expressed in apparel elements implied the community spirit, nature worship, and folk beliefs. As an attempt to understand the Ukrainian fashion, this study is significant in the aspect of expanding, widely utilizing, and expanding the range of understanding of Ukrainian fashion. Therefore, there should be more active researches on Ukrainian fashion, so Vyshyvanka can be more widely used as a design element.