• Title/Summary/Keyword: 고속도 카메라

Search Result 448, Processing Time 0.025 seconds

A Study on the Transition of Hydrogen-Air and LPG-Air Explosion to Fire (수소와 액화석유 가스의 공기혼합기의 폭발 후 화재로 전이 연구)

  • Oh Kyu-Hyung;Lee Sung-Eun;Rhie Kwang-Won
    • Journal of the Korean Society of Safety
    • /
    • v.19 no.4 s.68
    • /
    • pp.150-154
    • /
    • 2004
  • Gas explosion characteristics of hydrogen and liquefied petroleum gas(LPG) were measured in 6L cylindrical vessel, and experiment for explosion to fire transition phenomena of the gases were carried out using the 270L vessel. Explosion characteristics were measured using the stain type pressure transducer and explosion to fire transition phenomena was analyzed with the hish-speed camera. Base on the experiment, it was found that explosion pressure was most high slightly above the stoichiometric concentration, and explosion pressure rise rate and flame propagation velocity were proportional to the combustion velocity. And we find that those kind of explosion characteristics affect the explosion-to-fire transition, in addition, explosion flame temperature, flame residence time, are important parameters in explosion-to-fire transition.

Phosphorous Removal by Al(III) and Fe(III) Coagulants and Visualization of Flocs (Al(III), Fe(III)계 응집제의 인 제거 특성 및 플럭의 가시화)

  • Lee, Sang-Wha;Lee, Ku-Suk;Kang, Ik-Joong;Yoon, Hyon-Hee;Haam, Seung-Joo;Kwak, Jong-Woon
    • Applied Chemistry for Engineering
    • /
    • v.16 no.1
    • /
    • pp.74-80
    • /
    • 2005
  • The effective removal of turbid-inducing particulates and algae-inducing phosphorous was systematically investigated by the variation of physico-chemical parameters such as pH, alkalinity, and coagulant types. Al(III)-based and Fe(III)-based coagulants exhibited high removal efficiency of turbidity and phosphorous at optimal pH ranges of 7~9, in which zeta potential nearly approached to zero. The removal rate of turbidity rapidly increased with the increase of coagulant dosages, whereas the removal rate of phosphorous gradually increased due to an equivalent reaction of phosphorous with metallic ions. The generation of flocs during coagulation was visualized by high speed camera (Motion Scope 2000, Redlake Co.), and the images of singular flocs were captured by optical microscope. The flocs generated by Fe(III)-based coagulant was more compact than those induced by Al(III)-based coagulant, and the settlabiltiy of Fe(III)-induced flocs was superior to that of Al(III)-induced flocs.

Research on Micro-Movement Responses of Facial Muscles by Intimacy, Empathy, Valence (친밀도, 공감도, 긍정도에 따른 얼굴 근육의 미세움직임 반응 차이)

  • Cho, Ji Eun;Park, Sang-In;Won, Myoung Ju;Park, Min Ji;Whang, Min-Cheol
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.2
    • /
    • pp.439-448
    • /
    • 2017
  • Facial expression is important factor on social interaction. Facial muscle movement provides emotion information to develop social network. However, facial movement has less determined to recognize social emotion. This study is to analyze facial micro-movements and to recognize the social emotion such as intimacy, empathy, and valence. 76 university students were presented to the stimuli for social emotions and was measure their facial expression using camera. As a results, facial micro-movement. showed significant difference of social emotion. After extracting the movement amount of 3 unconscious muscles and 18 conscious muscles, Dominant Frequency band was confirmed. While muscle around the nose and cheek showed significant difference in the intimacy, one around mouth did in the empathy and one around jaw in the valence. The results proposed new facial movement to express social emotion in virtual avatars and to recognize social emotion.

Kinetic Analysis for Providing Education Cues on Left and Right Maneuvers of Body by Stance Width (스탠스 폭에 따른 신체 좌우 이동의 교육단서 제공을 위한 운동역학적 분석)

  • Lee, Dong-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.15 no.8
    • /
    • pp.556-563
    • /
    • 2015
  • The purpose of this study was to analyzed body movement of the right and left directions relative to stance width. Seven college students(male, height $174.9{\pm}4.8cm$, weight $70.9{\pm}6.6kg$) participated in this study. For the purpose of this study, nine high-speed cameras and two force plates was utilized. Stance width was limited into small stance width(mean 42.9cm) and large stance width(mean 65cm). The results showed that (1) the small stance width took shorter time than the large stance during landing of the right feet to toe-off; (2) the small stance width was took longer movement of the right feet after split step comparing to the large stance; (3)there was no significant difference in the speed of center of gravity between toe-off and maximum speed; (4) the small stance width was greater angles to hip joint and knee joint during toe-off of the right feet comparing to the large stance; (5) the was no significant difference in values for force plates between the small stance and the large stance width during toe-off of the right feet.

Frequency-Equivalence Ratio Correlation Analysis of Methane-Air Premixed Flame Influenced by Ultrasonic Standing Wave (I) (정상초음파의 영향을 받는 메탄-공기 예혼합화염의 주파수-당량비 상관도 분석(I))

  • Kim, Min Sung;Kim, Jeong Soo;Koo, Jaye;Kwon, Oh Chae
    • Journal of the Korean Society of Propulsion Engineers
    • /
    • v.19 no.4
    • /
    • pp.37-44
    • /
    • 2015
  • An experimental study was performed for the analysis of frequency-equivalence ratio correlation in the methane-air premixed flame influenced by ultrasonic standing wave. Evolutionary features of the propagating flame were caught by high-speed camera, and the variation of flame-behavior including local velocities was investigated in detail using a post-processing analysis of the high-speed images. It was found that propagation-velocity augmentation of the methane-air premixed flame by the intervention of ultrasonic standing wave was made in leaner mixture, but the velocity diminished when the strength of chemical reaction was saturated around the slightly fuel-rich side of stoichiometry.

An Experimental Study on the Flashback and Re-ignition Structure with a V-gutter type Flameholder (V-gutter형 보염기에서 발생하는 화염의 역화 및 재점화 구조에 관한 실험적 연구)

  • Jeong, Chan-Yeong;Kim, Tae-Sung;Song, Jin-Kwan;Yoon, Young-Bin
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.603-607
    • /
    • 2011
  • Structure of flashback and reignition occurring near flameholder was experimentally investigated in a model combustor with V-gutter flameholder. The combustor has a long duct shape with cross section of $40{\times}40mm$ and City Nature Gas(CNG) were used as fuel. Measurements of chemiluminescence with high speed camera was used for visualization of flame structure. In the lean case, flashback distance depend on equivalent ratio. New flame occurred at the front tip of flameholder when flashback. Flashback flame moved toward downstream direction of combustor because mixture flow velocity had increased, and then re-ignition was caused by entering flow into recirculation zone that is formed behind the flameholder.

  • PDF

Estimation of Dynamic Brazilian Tensile Strengths of Rocks Using Split Hopkinson Pressure Bar (SHPB) System (스플릿 홉킨슨 압력봉 실험장비를 이용한 암석의 동적 압열인장강도 평가에 관한 연구)

  • Yang, Jung-Hun;Ahn, Jung-Lyang;Kim, Seung-Kon;Song, Young-Su;Sung, Nak-Hoon;Lee, Youn-Kyou;Cho, Sang-Ho
    • Tunnel and Underground Space
    • /
    • v.21 no.2
    • /
    • pp.109-116
    • /
    • 2011
  • In this study, we estimated the dynamic tensile strength and strain rate from Brazilian tensile test using Split Hopkinson Pressure Bar (SHPB) system. A pulse shaping technique, which controls the shape of the impactinduce incident waves, was used for achieving the dynamic stress equilibrium and constant strain rate before fracture of rock samples. Three kinds of rock type, Inada granite, Kimachi sandstone and Tage tuff were prepared as 50mm in diameter and 26 mm in thickness. The high-speed videography system was used to observe the fracture processes of the rock samples. As the results of the tests, the ratio of dynamic tensile strength and static tensile strength was 11.9 for Inada granite, 8.5 for Kimachi sandstone and 9.2 for Tage tuff.

Predicting soft tissue artefact with linear mixed models (선형혼합모형을 이용한 피부움직임 오차의 예측)

  • Kim, Jinuk
    • The Korean Journal of Applied Statistics
    • /
    • v.31 no.3
    • /
    • pp.353-366
    • /
    • 2018
  • This study uses mixed-effects models to predict thigh soft tissue artefact (STA), relative movement of soft tissue such as skin to femur occurring during hip joint motions. The random effects in the model were defined as STA and the fixed effects in the model were considered as skeletal motion. Five male subjects without musculoskeletal disease were selected to perform various hip joint rotational motions. Linear mixed-effects models were applied to markers' position vectors acquired from non-invasive method, photogrammetry. Predicted random effects showed similar patterns of STA among subjects. Large magnitudes of STA appeared on the points near the hip joint regardless of sides; however, small values appeared on the distal anterior.

Experimental Investigation on the Gap Cavitation of Semi-spade Rudder (Semi-spade 타의 간극 캐비테이션에 대한 실험적 연구)

  • Paik, Bu-Geun;Kim, Kyung-Youl;Ahn, Jong-Woo;Kim, Yong-Soo;Kim, Sung-Pyo;Park, Je-Jun
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.43 no.4 s.148
    • /
    • pp.422-430
    • /
    • 2006
  • The horn and movable parts around the gap of the conventional semi-spade rudder are visualized by high speed CCD camera with the frame rate of 4000 fps (frame per second) to study the unsteady cavity pattern on the rudder surface and gap. In addition, the pressure measurements are conducted on the rudder surface and inside the gap to find out the characteristics of the flow behavior. The rudder without propeller wake is tested at the range of $1.0{\leq}{\sigma}_v\;1.6$ and at the rudder deflection angle of $-8{\leq}{\theta}{\leq}10^{\circ}$. The time resolved cavity images are captured and show strong cavitation around the rudder gap in all deflection angles. As the deflection angle gets larger, the flow separated from the horn surface increases the strength of cavitation. The accelerated flow along the horn decreases its pressure and the separated flow from the horn increases the pressure abruptly. The pressure distribution inside the gap reveals the flow moving from the pressure to suction side. In the negative deflection angle, the turning area on the movable part initiates the flow separation and cavitation on it.

Design and Implementation of the System for Automatic Classification of Blood Cell By Image Analysis (영상분석을 통한 혈구자동분류 시스템의 설계 및 구현)

  • Kim, Kyung-Su;Kim, Pan-Koo
    • Journal of the Korean Institute of Telematics and Electronics C
    • /
    • v.36C no.12
    • /
    • pp.90-97
    • /
    • 1999
  • Recently, there have been many researches to automate processing and analysing image data in medical field, due to the advance of image processing techniques, the fast communication network and high performance hardware. In this paper, we design and implement the system based on the multi-layer neural network model to be able to analyze, differentiate and count blood cells in the peripheral blood image. To do these, we segment red and white-blood cell in blood image acquired from microscope with CCD(Charge-coupled device) camera and then apply the various feature extraction algorithms to classify. In addition to, we reduce multi-variate feature number using PCA(Principle Component Analysis) to construct more efficient classifier. So, in this paper, we are sure that the proposed system can be applied to a pathological guided system.

  • PDF