• Title/Summary/Keyword: Visualization Image

Search Result 963, Processing Time 0.022 seconds

Flow Characteristics for PIV Visualization at Junction Duct (PIV 가시화에 의한 합류덕트에서의 유동특성)

  • Kim, M.K.;Kwon, O.B.;Bae, D.S.
    • Journal of Power System Engineering
    • /
    • v.9 no.4
    • /
    • pp.45-50
    • /
    • 2005
  • Characteristics of flows at T-junction duct with and without orifices are investigated in this paper. Experiments and PIV visualization were carried out for several flow rates. Two-dimensional PIV experimental apparatus was decided by numerical analysis. PIV visualization was also coded to visualize flow fields at junctions for two-dimensional case. For the PIV visualization system, Grey-Level Cross-Correlation particle tracking algorithm was used to calculate the flow fields. Vinyl chloride polymer particles of $100{\sim}150{\mu}m$ of diameter are used in this visualization. The PIV visualization results showed relatively good agreement with Experimental data.

  • PDF

Visualization of Tooth for Non-Destructive Evaluation from CT Images

  • Gao, Hui;Chae, Oksam
    • Journal of the Korean Society for Nondestructive Testing
    • /
    • v.29 no.3
    • /
    • pp.207-213
    • /
    • 2009
  • This paper reports an effort to develop 3D tooth visualization system from CT sequence images as a part of the non-destructive evaluation suitable for the simulation of endodontics, orthodontics and other dental treatments. We focus on the segmentation and visualization for the individual tooth. In dental CT images teeth are touching the adjacent teeth or surrounded by the alveolar bones with similar intensity. We propose an improved level set method with shape prior to separate a tooth from other teeth as well as the alveolar bones. Reconstructed 3D model of individual tooth based on the segmentation results indicates that our technique is a very conducive tool for tooth visualization, evaluation and diagnosis. Some comparative visualization results validate the non-destructive function of our method.

Enhancement of Ultrasonic Sonoluminescence Image Using Digital Image Processing (디지털 영상처리를 이용한 초음파 소노루미네센스 이미지 개선)

  • Kim, Jung-Soon;Jo, Mi-Sun;Mun, Kwan-Ho;Ha, Kang-Lyeol;Jun, Byung-Doo;Kim, Moo-Joon
    • The Journal of the Acoustical Society of Korea
    • /
    • v.26 no.8
    • /
    • pp.409-414
    • /
    • 2007
  • In spite of many studies of the acoustic field visualization by using sonoluminescence phenomena, the visualization method has not been used widely because it needs high acoustic intensity to get the luminescence intensity enough to observe. Recently, the digital camera with high resolution and big memory makes it possible to get the digital image data even though the brightness of the image is too weak to observe with naked eyes. In this study we investigated the variation of sonoluminescence intensity with the acoustic intensity from an ultrasonic transducer. From this result, the inverse function, which makes the tendency of the variation to linear, was obtained. Using the order of the inverse function, we can expect a matching function. Applying the matching function to digital image data, the distribution of the histogram could be controlled appropriately and the image from relatively weak acoustic intensity could be enhanced by the method.

A Study on the Lubricating Air-layer Detection Techniques with Digital Image Analysis in Flat Plate Air Lubrication Test (공기윤활평판실험에서 디지털 영상분석을 통한 윤활공기막 검출기법)

  • Park, SeongHyeon;Lee, Inwon
    • Journal of the Korean Society of Visualization
    • /
    • v.14 no.1
    • /
    • pp.27-32
    • /
    • 2016
  • The reduction of $CO_2$ emissions has been a key target in the Marine Industry since the IMO's Marine Environment Protection Committee published its findings in 2009. The representative emission index is termed as the EEDI (Energy Efficiency Design Index) for the new ships. Among various flow control techniques ever proposed, the air lubrication method is the one of most promising one in terms of practical applicability. The present study examines the basic characteristics of the flat plate test with intention of applying the air lubrication technology to the reduction of the resistance of a ship. Image analysis technique is proposed as a tool to quantify the effectiveness of the air lubrication method.

Droplet size measurement using image processing method (이미지프로세싱 기법을 이용한 액적크기 측정)

  • Lim Byoungjik;Jung Kihoon;Khil Taeock;Yoon Youngbin
    • Journal of the Korean Society of Visualization
    • /
    • v.2 no.1
    • /
    • pp.25-31
    • /
    • 2004
  • Droplet size is one of the most important parameter which controls the performance of the combustion system using liquid fuel or oxidizer. Droplet formation and its size are mainly affected by the injection velocity and ambient gas density. Recently, droplet size measurement was conducted by PDPA or Malvern particle analyzer using laser light. But at this paper image processing method was developed to measure droplet size. And its validation was investigated with reticle.

  • PDF

Image Analysis Method for the Performance Evaluation of Marine Antifouling Coatings (화상 분석을 통한 선박 방오도료의 성능 평가)

  • Park, Hyun;Chun, Ho Hwan;Lee, Inwon
    • Journal of the Korean Society of Visualization
    • /
    • v.11 no.2
    • /
    • pp.18-26
    • /
    • 2013
  • An accurate and reliable performance evaluation technique is indispensable for the development of marine antifouling coatings. The existing standard practice is however, based on the visual observation of biofouling settlement area, which is prone to the subjective judgment of the inspector. In spite of the above mentioned importance, a systematic and objective fouling evaluation technique has not yet been introduced. In this study, a novel quantitative antifouling performance evaluation method for marine antifouling paints is devised based on the image analysis of panel immersion test results. The present image analysis method is to quantify settlement area for each fouling category by distinctive color. The fouling categories are set as unfouled, biofilm, green algae, brown algae, calcareous animal and spongy animal with specific HSL (Hue, Saturation, Lightness) color ranges. In order to assess the effectiveness of the proposed method, static immersion tests for three antifouling coatings were undertaken for two years.

Research for development of our own image processing code for neutron tomography (중성자 토모그래피를 위한 영상처리 자체코드 개발 연구)

  • Kim, Jin Man;Kim, TaeJoo;Yu, Dong In
    • Journal of the Korean Society of Visualization
    • /
    • v.18 no.1
    • /
    • pp.44-49
    • /
    • 2020
  • Neutron radiography has been widely used in many research areas due to its different characteristics from X-rays. Neutron tomography is a powerful tool because it can clearly show the inside of an object that the eye cannot see. However, generally, commercial software is used for the reconstruction of neutron tomography. It means that maintenance costs are incurred and analysis is inefficient in some cases. In this respect, our own image processing code is required to reconstruct neutron images efficiently. In this study, an image processing code is developed for reconstruction of cross-sectional images from neutron radiography taken from the side of the object. Using the developed code, cross-sectional images of the sample are successfully reconstructed.

BM3D and Deep Image Prior based Denoising for the Defense against Adversarial Attacks on Malware Detection Networks

  • Sandra, Kumi;Lee, Suk-Ho
    • International journal of advanced smart convergence
    • /
    • v.10 no.3
    • /
    • pp.163-171
    • /
    • 2021
  • Recently, Machine Learning-based visualization approaches have been proposed to combat the problem of malware detection. Unfortunately, these techniques are exposed to Adversarial examples. Adversarial examples are noises which can deceive the deep learning based malware detection network such that the malware becomes unrecognizable. To address the shortcomings of these approaches, we present Block-matching and 3D filtering (BM3D) algorithm and deep image prior based denoising technique to defend against adversarial examples on visualization-based malware detection systems. The BM3D based denoising method eliminates most of the adversarial noise. After that the deep image prior based denoising removes the remaining subtle noise. Experimental results on the MS BIG malware dataset and benign samples show that the proposed denoising based defense recovers the performance of the adversarial attacked CNN model for malware detection to some extent.

A rubber o-ring defect detection system using data augmentation based on the SinGAN and random forest algorithm (SinGAN기반 데이터 증강과 random forest알고리즘을 이용한 고무 오링 결함 검출 시스템)

  • Lee, Yong Eun;Lee, Han Sung;Kim, Dae Won;Kim, Kyung Chun
    • Journal of the Korean Society of Visualization
    • /
    • v.19 no.3
    • /
    • pp.63-68
    • /
    • 2021
  • In this study, data was augmentation through the SinGAN algorithm using small image data, and defects in rubber O-rings were detected using the random forest algorithm. Unlike the commonly used data augmentation image rotation method to solve the data imbalance problem, the data imbalance problem was solved by using the SinGAN algorithm. A study was conducted to distinguish between normal products and defective products of rubber o-ring by using the random forest algorithm. A total of 20,000 image date were divided into transit and testing datasets, and an accuracy result was obtained to distinguish 97.43% defects as a result of the test.

Optimizing the reconstruction filter in cone-beam CT to improve periodontal ligament space visualization: An in vitro study

  • Houno, Yuuki;Hishikawa, Toshimitsu;Gotoh, Ken-ichi;Naitoh, Munetaka;Mitani, Akio;Noguchi, Toshihide;Ariji, Eiichiro;Kodera, Yoshie
    • Imaging Science in Dentistry
    • /
    • v.47 no.3
    • /
    • pp.199-207
    • /
    • 2017
  • Purpose: Evaluation of alveolar bone is important in the diagnosis of dental diseases. The periodontal ligament space is difficult to clearly depict in cone-beam computed tomography images because the reconstruction filter conditions during image processing cause image blurring, resulting in decreased spatial resolution. We examined different reconstruction filters to assess their ability to improve spatial resolution and allow for a clearer visualization of the periodontal ligament space. Materials and Methods: Cone-beam computed tomography projections of 2 skull phantoms were reconstructed using 6 reconstruction conditions and then compared using the Thurstone paired comparison method. Physical evaluations, including the modulation transfer function and the Wiener spectrum, as well as an assessment of space visibility, were undertaken using experimental phantoms. Results: Image reconstruction using a modified Shepp-Logan filter resulted in better sensory, physical, and quantitative evaluations. The reconstruction conditions substantially improved the spatial resolution and visualization of the periodontal ligament space. The difference in sensitivity was obtained by altering the reconstruction filter. Conclusion: Modifying the characteristics of a reconstruction filter can generate significant improvement in assessments of the periodontal ligament space. A high-frequency enhancement filter improves the visualization of thin structures and will be useful when accurate assessment of the periodontal ligament space is necessary.