• Title/Summary/Keyword: high-speed imaging

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New Era of Management Concept on Pulmonary Fibrosis with Revisiting Framework of Interstitial Lung Diseases

  • Azuma, Arata;Richeldi, Luca
    • Tuberculosis and Respiratory Diseases
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    • v.83 no.3
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    • pp.195-200
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    • 2020
  • The disease concept of interstitial lung disease with idiopathic pulmonary fibrosis at its core has been relied on for many years depending on morphological classification. The separation of non-specific interstitial pneumonia with a relatively good prognosis from usual interstitial pneumonia is also based on the perception that morphology enables predict the prognosis. Beginning with dust-exposed lungs, initially, interstitial pneumonia is classified by anatomical pathology. Diagnostic imaging has dramatically improved the diagnostic technology for surviving patients through the introduction of high-resolution computed tomography scan. And now, with the introduction of therapeutics, the direction of diagnosis is turning. It can be broadly classified into to make known the importance of early diagnosis, and to understand the importance of predicting the speed of progression/deterioration of pathological conditions. For this reason, the insight of "early lesions" has been discussed. There are reports that the presence or absence of interstitial lung abnormalities affects the prognosis. Searching for a biomarker is another prognostic indicator search. However, as is the case with many chronic diseases, pathological conditions that progress linearly are extremely rare. Rather, it progresses while changing in response to environmental factors. In interstitial lung disease, deterioration of respiratory functions most closely reflect prognosis. Treatment is determined by combining dynamic indicators as faithful indicators of restrictive impairments. Reconsidering the history being classified under the disease concept, the need to reorganize treatment targets based on common pathological phenotype is under discussed. What is the disease concept? That aspect changes with the discussion of improving prognosis.

Dynamic characteristics between waves and a floating cylindrical body connected to a tension-leg mooring cable placed in a simulated offshore environment

  • Song, Juhun;So, Soo-Hyun;Lim, Hee-Chang
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.8 no.4
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    • pp.375-385
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    • 2016
  • Given the rapid progress made in understanding the dynamics of an offshore floating body in an ocean environment, the present study aimed to simulate ocean waves in a small-sized wave flume and to observe the motion of a cylindrical floating body placed in an offshore environment. To generate regular ocean waves in a wave flume, we combined a wave generator and a wave absorber. In addition, to precisely visualise the oscillation of the body, a set of light-emitting diode illuminators and a high-speed charge-coupled device camera were installed in the flume. This study also focuses on the spectral analysis of the movement of the floating body. The wave generator and absorbers worked well to simulate stable regular waves. In addition, the simulated waves agreed well with the plane waves predicted by shallow-water theory. As the period of the oncoming waves changed, the movement of the floating body was substantially different when tethered to a tension-leg mooring cable. In particular, when connected to the tension-leg mooring cable, the natural frequency of the floating body appeared suddenly at 0.391 Hz as the wave period increased.

A Study on the Arc Characteristics of Wires During a Short-Circuit by the Diameter (전선 직경 변화에 따른 단락 아크 특성에 관한 연구)

  • Kim, Young-Seok;Shong, Kil-Mok;Kim, Dong-Ook;Kim, Dong-Woo;Choi, Chung-Seog
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.495-498
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    • 2004
  • In this paper, the arc and flame characteristics of wires were studied during a short-circuit. The short-circuit angle between wires was fixed as $90^{\circ}$ and the experiments were conducted on bare copper wires by varying the diameter of wires. The arc and flame patterns were taken by a high speed imaging system. The direction of arc and flame was explained with Lorentz force. After the short-circuit experiment, the shapes of molten wires were analyzed by a stereo microscope. In the results of experiment, the arc and flame of wires showed particular patterns. The flame characteristics by the diameter of wires were analyzed using a HSIS. We could find out the arc characteristics of wires which were different by the diameter.

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A Real-time Vision Inspection System at a Laver Production Line (해태 생산라인에서의 실시간 시각검사 시스템)

  • Kim, Gi-Weon;Kim, Bong-Gi
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1136-1140
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    • 2007
  • In this paper dose a laver surface check using a real time image process. This system does false retrieval of a laver at a laver production line. At first, a laver image was read in real time using a CCD camera. In this paper, we use an area scan CCD camera. Image is converted into a binary code image using a high-speed imaging process board afterwards. A laver feature is extracted by a binary code image. Surface false retrieval is finally executed using a laver feature. In this paper, we use an area feature of a laver image.

Fast Noise Reduction Approach in Multifocal Multiphoton Microscopy Based on Monte-Carlo Simulation

  • Kim, Dongmok;Shin, Younghoon;Kwon, Hyuk-Sang
    • Current Optics and Photonics
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    • v.5 no.4
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    • pp.421-430
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    • 2021
  • The multifocal multiphoton microscopy (MMM) enables high-speed imaging by the concurrent scanning and detection of multiple foci generated by lenslet array or diffractive optical element. The MMM system mainly suffers from crosstalk generated by scattered emission photons that form ghost images among adjacent channels. The ghost image which is a duplicate of the image acquired in sub-images significantly degrades overall image quality. To eliminate the ghost image, the photon reassignment method was established using maximum likelihood estimation. However, this post-processing method generally takes a longer time than image acquisition. In this regard, we propose a novel strategy for rapid noise reduction in the MMM system based upon Monte-Carlo (MC) simulation. Ballistic signal, scattering signal, and scattering noise of each channel are quantified in terms of photon distribution launched in tissue model based on MC simulation. From the analysis of photon distribution, we successfully eliminated the ghost images in the MMM sub-images. If the priori MC simulation under a certain optical condition is established at once, our simple, but robust post-processing technique will continuously provide the noise-reduced images, while significantly reducing the computational cost.

Hydrodynamic effects of heater lengths on pool boiling critical heat flux (히터 길이가 수조비등 임계열유속에 미치는 수력학적 영향)

  • Su Cheong Park;Do Yeon Kim;Seon Ho Choi;Chang Hoon Lee;Younghun Lim;Chi Young Lee;Yeon Won Lee;Dong In Yu
    • Journal of the Korean Society of Visualization
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    • v.21 no.1
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    • pp.67-73
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    • 2023
  • In the study, pool boing critical heat flux (CHF) was experimentally investigated depending on the length of heaters. A smooth silicon oxide surfaces are used as the boiling surfaces. As the results of pool boiling experiments based on distilled water in ambient pressure condition, the CHF decreased as the length of the heater increased. By the high speed imaging, it was shown that the number of vapor columns increased as the length of the heater increased. Comparing the number of vapor columns and the CHF according to the heater length, the change in the CHF according to the heater length was analyzed based on the hydrodynamic instability.

VISUALIZATION AND MEASUREMENT OF A NARROW-CONE DI GASOLINE SPRAY FOR THE IMPINGEMENT ANALYSIS

  • Park, J.S.;Im, K.S.;Kim, H.S.;Lai, M.C.
    • International Journal of Automotive Technology
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    • v.5 no.4
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    • pp.221-238
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    • 2004
  • Wall interactions of direct injection spray were investigated using laser-sheet imaging, shadowgraphy, wetted footprint and phase Doppler interferometry techniques. A narrow-cone high-pressure swirl injector is used to inject iso-octane fuel onto a plate, which has three different impact angles inside a pressurized chamber. Heated air and plate conditions were compared with unheated cases. Injection interval was also varied in the heated case to compare dry- and wet- wall impingement behaviors. High-speed macroscopic Mie-scattering images showed that presence of wall and air temperature has only minor effect on the bulk spray structure and penetration speed for the narrow-cone injector tested. The overall bulk motions of the spray plume and its spatial position at a given time are basically unaffected until a few millimeters before impacting the wall. The surface properties of the impact surface, such as the temperature, the presence of a preexisting liquid film also have a small effect on the amount of wetting or the wetted footprint; however, they have strong influence on what occurs just after impact or after a film is formed. The shadowgraph in particular shows that the plate temperature has a significant effect on vapor phase propagation. Generally, 10-20% faster horizontal vapor phase propagation is observed along the wall at elevated temperature condition. For impingement onto a preexisting film, more splash and evaporation were also observed. Contrary to some preconceptions, there is no significant splashing and droplet rebounding from surfaces that are interposed in the path of the DI gasoline spray, especially for the oblique impact angle cases. There also appears to be a dense spray front consists of large sac spray droplets in the oblique impact angle cases. The bulk of the spray is not impacted on the surface, but rather is deflected by it The microscopic details as depicted by phase Doppler measurements show that the outcome of the droplet impaction events can be significantly influenced. Only droplets at the spray front have high enough Weber numbers for wall impact to wet, splash or rebound. Using the sign of vertical velocity, the time-resolved downward droplets and upward droplets are compared. The Weber number of upward moving droplets, which seldom exceeds unity, also decreases as the impact angle decreases, as the droplets tend to impact less and move along the wall in the deflected spray plume.

Robust Dynamic Projection Mapping onto Deforming Flexible Moving Surface-like Objects (유연한 동적 변형물체에 대한 견고한 다이내믹 프로젝션맵핑)

  • Kim, Hyo-Jung;Park, Jinho
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.897-906
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    • 2017
  • Projection Mapping, also known as Spatial Augmented Reality(SAR) has attracted much attention recently and used for many division, which can augment physical objects with projected various virtual replications. However, conventional approaches towards projection mapping have faced some limitations. Target objects' geometric transformation property does not considered, and movements of flexible objects-like paper are hard to handle, such as folding and bending as natural interaction. Also, precise registration and tracking has been a cumbersome process in the past. While there have been many researches on Projection Mapping on static objects, dynamic projection mapping that can keep tracking of a moving flexible target and aligning the projection at interactive level is still a challenge. Therefore, this paper propose a new method using Unity3D and ARToolkit for high-speed robust tracking and dynamic projection mapping onto non-rigid deforming objects rapidly and interactively. The method consists of four stages, forming cubic bezier surface, process of rendering transformation values, multiple marker recognition and tracking, and webcam real time-lapse imaging. Users can fold, curve, bend and twist to make interaction. This method can achieve three high-quality results. First, the system can detect the strong deformation of objects. Second, it reduces the occlusion error which reduces the misalignment between the target object and the projected video. Lastly, the accuracy and the robustness of this method can make result values to be projected exactly onto the target object in real-time with high-speed and precise transformation tracking.

Development of Portable Laryngeal Stroboscope (휴대형 후두 스트로보스콥의 개발)

  • Lee, Jae-Woo;Kwon, Soon-Bok;Lee, Byung-Joo;Lee, Jin-Choon;Goh, Eui-Kyung;Chon, Kyong-Myong;Wang, Soo-Geun;Ro, Jung-Hoon
    • Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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    • v.17 no.1
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    • pp.28-37
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    • 2006
  • Purpose: Evaluation of vocal cord vibration is very important in cases of voice disorders. There are several equipments for examining the vocal fold vibration such as laryngeal stroboscope, ultra high-speed digital imaging system, and videokymograph. Among these, laryngeal stroboscope is the most popular equipment because of easy to examine the laryngeal pathology. However, current laryngo-stroboscopes are too bulky to move and relatively expensive. The purpose of this research is to develope a portable laryngeal stroboscope of equivalent performance with the current equipments. Methods and Materials: Recently developed high luminescent white LEDs(light emitting diodes) are placed at the head of the endoscope as light sources for the CCD image sensor which is also placed at the head with imaging lens. This arrangement eliminates the bulky light source like expensive halogen or xenon lamps as well as the optical light guiding cables. The LEDs are controlled to flash in phase with the voice frequency of the examinee. The CCD captures these strobo images and converts them into video signals for examinations. Results: There was no functional differences between preexisting stroboscope and the newly developed stroboscope of this study. LED light sources and microprocessor based control circuits of the stroboscope enabled the development of flicker-less, hand-held, portable and battery-operating stroboscope. Conclusion: The developed stroboscope is cost-effective, small-sized, easy to use and very easy desirable to bring and to use in any place.

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Combustion Characteristics of Single Droplet of Diesel with Bio-diesel for Their Mixing Ratios and Sizes (경유와 바이오 디젤 액적의 혼합비율과 크기에 따른 연소특성)

  • Jeong, Man-Seok;Lee, Kyung-Hwan
    • Journal of Energy Engineering
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    • v.18 no.2
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    • pp.101-107
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    • 2009
  • The combustion characteristics of a single droplet of diesel and bio-diesel have been investigated experimentally with varying droplet size, ambient temperature and compound ratio in a high temperature chamber. The fuels used were diesel with bio-diesel contents varied from 0% to 100%. Each experiment has been performed from 970K to 1070K by 50K intervals. Imaging with a high-speed digital camera was adopted to measure the ignition delay and flame life-time, as well as to observe micro-explosion behavior. The increase of droplet size and decrease of furnace temperature cause an increase of the ignition delay time. As the bio-diesel content decreases, the ignition delay increases and the micro-explosion behavior is strengthened. It is also confirmed that the full combustion time decreases as the micro-explosion occurred.