• 제목/요약/키워드: real scale experimental

검색결과 339건 처리시간 0.031초

아트리움 공간에서의 화재성상에 관한 축소모델 실험연구 (The Experimental Study of Fire Properties in Reduced-scale Atrium Space)

  • 류승관;김충익;유홍선
    • 한국화재소방학회논문지
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    • 제13권4호
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    • pp.30-37
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    • 1999
  • 본 연구에서는 아트리움 공간에서의 화재성상을 파악하기 위해 실물 실현의 대안으로서 축소 모형 실험을 수행하였다. 연속방정식, 운동량 보존 방정식, 에너지 보존 방정식과 같은 지배 방정식의 차원해석으로부터 추론된 $\pi$변수로부터 축소법칙을 얻었다. 이 축소법칙에 따라 일본의 시반스 아트리움을 1/50로 축소한 모형에서 실험을 수행하였다. 여기서 얻어진결과를 실물 실험 결과와 비교하였다. 더 나아가 이러한 결과들은 레이저 관광을 이용한 가시화 시스템에 의해 가시화 되어졌다.

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제트홴에 의해 형성되는 터널내 유동의 실험 및 수치적 해석 (Numerical and Experimental Analysis of Tunnel Flow Induced by Jet Fan)

  • 김정엽;양상호
    • 한국유체기계학회 논문집
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    • 제13권3호
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    • pp.59-64
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    • 2010
  • To analyze the three-dimensional flow in tunnel caused by operation of jet fan, both experimental and computational studies have been conducted. The experimental analysis of tunnel flow induced by jet fan is conducted on a real-scale apparatus with jet fan and tunnel, and air velocity at the monitoring points is measured for variation of fan's RPM. The three-dimensional numerical analysis including tunnel and jet fan is carried out for the same geometric configuration as the experimental analysis. The experimental and computational results are compared to examine the applicability of the numerical method.

A versatile small-scale structural laboratory for novel experimental earthquake engineering

  • Chen, Pei-Ching;Ting, Guan-Chung;Li, Chao-Hsien
    • Earthquakes and Structures
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    • 제18권3호
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    • pp.337-348
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    • 2020
  • Experimental testing has been considered as one of the most straightforward approaches to realize the structural behavior for earthquake engineering studies. Recently, novel and advanced experimental techniques, which combine numerical simulation with experimental testing, have been developed and applied to structural testing practically. However, researchers have to take the risk of damaging specimens or facilities during the process of developing and validating new experimental methods. In view of this, a small-scale structural laboratory has been designed and constructed in order to verify the effectiveness of newly developed experimental technique before it is applied to large-scale testing for safety concerns in this paper. Two orthogonal steel reaction walls and one steel T-slotted reaction floor are designed and analyzed. Accordingly, a large variety of experimental setups can be completed by installing servo-hydraulic actuators and fixtures depending on different research purposes. Meanwhile, a state-of-the-art digital controller and multiple real-time computation machines are allocated. The integration of hardware and software interfaces provides the feasibility and flexibility of developing novel experimental methods that used to be difficult to complete in conventional structural laboratories. A simple experimental demonstration is presented which utilizes part of the hardware and software in the small-scale structural laboratory. Finally, experimental layouts of future potential development and application are addressed and discussed, providing the practitioners with valuable reference for experimental earthquake engineering.

스케일 불변적인 연산량 감소를 위한 경량 실시간 소형 적외선 표적 검출 알고리즘 (A Lightweight Real-Time Small IR Target Detection Algorithm to Reduce Scale-Invariant Computational Overhead)

  • 반종희;유준혁
    • 대한임베디드공학회논문지
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    • 제12권4호
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    • pp.231-238
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    • 2017
  • Detecting small infrared targets from the low-SCR images at a long distance is very hard. The previous Local Contrast Method (LCM) algorithm based on the human visual system shows a superior performance of detecting small targets by a background suppression technique through local contrast measure. However, its slow processing speed due to the heavy multi-scale processing overhead is not suitable to a variety of real-time applications. This paper presents a lightweight real-time small target detection algorithm, called by the Improved Selective Local Contrast Method (ISLCM), to reduce the scale-invariant computational overhead. The proposed ISLCM applies the improved local contrast measure to the predicted selective region so that it may have a comparable detection performance as the previous LCM while guaranteeing low scale-invariant computational load by exploiting both adaptive scale estimation and small target feature feasibility. Experimental results show that the proposed algorithm can reduce its computational overhead considerably while maintaining its detection performance compared with the previous LCM.

축소모형 강관추진실험 경향 분석 (Analysis of pipe roof method test with a reduced-scale model)

  • 엄기영;정관동;이성혁;천정연;장희정;이종태
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2010년도 춘계학술대회 논문집
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    • pp.664-670
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    • 2010
  • The study on mechanical behavior of the structure at the site includes experimental method and numerical analysis method. Experimental method is categorized into true-scale test and laboratory model test. A laboratory model test is to monitor the failure mechanism with a model simulated similar with a real ground so as to identify the quantitative result, while a true-scale model test is the approach which enables to identify the potential problems that may occur with a simulated construction situation similar with a real site circumstance. Thus this study was intended to carry out the experimental test of non open-cut excavation by pipe roof method which is mostly common in domestic sites. as well as was aimed at identifying the ground behavior occurred during pipe penetration using laboratory model test. Appropriate reduced-scale model was selected, taking into account of domestic geological characteristics and operation characteristics of traditional and high-speed rail trains and the qualitative evaluation of displacement was carried out based on a certain ground loss volume depending on excavation after categorizing trackbed settlement pattern by depth of top soil.

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라플라스 스케일스페이스 이론과 적응 문턱치를 이용한 크기 불변 표적 탐지 기법 (Scale Invariant Target Detection using the Laplacian Scale-Space with Adaptive Threshold)

  • 김성호;양유경
    • 한국군사과학기술학회지
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    • 제11권1호
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    • pp.66-74
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    • 2008
  • This paper presents a new small target detection method using scale invariant feature. Detecting small targets whose sizes are varying is very important to automatic target detection. Scale invariant feature using the Laplacian scale-space can detect different sizes of targets robustly compared to the conventional spatial filtering methods with fixed kernel size. Additionally, scale-reflected adaptive thresholding can reduce many false alarms. Experimental results with real IR images show the robustness of the proposed target detection in real world.

Development of a generalized scaling law for underwater explosions using a numerical and experimental parametric study

  • Kim, Yongtae;Lee, Seunggyu;Kim, Jongchul;Ryu, Seunghwa
    • Structural Engineering and Mechanics
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    • 제77권3호
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    • pp.305-314
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    • 2021
  • In order to reduce enormous cost of real-scale underwater explosion experiments on ships, the mechanical response of the ships have been analyzed by combining scaled-down experiments and Hopkinson's scaling law. However, the Hopkinson's scaling law is applicable only if all variables vary in an identical ratio; for example, thickness of ship, size of explosive, and distance between the explosive and the ship should vary with same ratio. Unfortunately, it is infeasible to meet such uniform scaling requirement because of environmental conditions and limitations in manufacturing scaled model systems. For the facile application of the scaling analysis, we propose a generalized scaling law that is applicable for non-uniform scaling cases in which different parts of the experiments are scaled in different ratios compared to the real-scale experiments. In order to establish such a generalized scaling law, we conducted a parametric study based on numerical simulations, and validated it with experiments and simulations. This study confirms that the initial peak value of response variables in a real-scale experiment can be predicted even when we perform a scaled experiment composed of different scaling ratios for each experimental variable.

Multi-Scale Dilation Convolution Feature Fusion (MsDC-FF) Technique for CNN-Based Black Ice Detection

  • Sun-Kyoung KANG
    • 한국인공지능학회지
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    • 제11권3호
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    • pp.17-22
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    • 2023
  • In this paper, we propose a black ice detection system using Convolutional Neural Networks (CNNs). Black ice poses a serious threat to road safety, particularly during winter conditions. To overcome this problem, we introduce a CNN-based architecture for real-time black ice detection with an encoder-decoder network, specifically designed for real-time black ice detection using thermal images. To train the network, we establish a specialized experimental platform to capture thermal images of various black ice formations on diverse road surfaces, including cement and asphalt. This enables us to curate a comprehensive dataset of thermal road black ice images for a training and evaluation purpose. Additionally, in order to enhance the accuracy of black ice detection, we propose a multi-scale dilation convolution feature fusion (MsDC-FF) technique. This proposed technique dynamically adjusts the dilation ratios based on the input image's resolution, improving the network's ability to capture fine-grained details. Experimental results demonstrate the superior performance of our proposed network model compared to conventional image segmentation models. Our model achieved an mIoU of 95.93%, while LinkNet achieved an mIoU of 95.39%. Therefore, it is concluded that the proposed model in this paper could offer a promising solution for real-time black ice detection, thereby enhancing road safety during winter conditions.

Black Ice Detection Platform and Its Evaluation using Jetson Nano Devices based on Convolutional Neural Network (CNN)

  • Sun-Kyoung KANG;Yeonwoo LEE
    • 한국인공지능학회지
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    • 제11권4호
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    • pp.1-8
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    • 2023
  • In this paper, we propose a black ice detection platform framework using Convolutional Neural Networks (CNNs). To overcome black ice problem, we introduce a real-time based early warning platform using CNN-based architecture, and furthermore, in order to enhance the accuracy of black ice detection, we apply a multi-scale dilation convolution feature fusion (MsDC-FF) technique. Then, we establish a specialized experimental platform by using a comprehensive dataset of thermal road black ice images for a training and evaluation purpose. Experimental results of a real-time black ice detection platform show the better performance of our proposed network model compared to conventional image segmentation models. Our proposed platform have achieved real-time segmentation of road black ice areas by deploying a road black ice area segmentation network on the edge device Jetson Nano devices. This approach in parallel using multi-scale dilated convolutions with different dilation rates had faster segmentation speeds due to its smaller model parameters. The proposed MsCD-FF Net(2) model had the fastest segmentation speed at 5.53 frame per second (FPS). Thereby encouraging safe driving for motorists and providing decision support for road surface management in the road traffic monitoring department.

원격조작을 위한 영상정보 기반의 햅틱인터렉션 방법: 매크로 및 마이크로 시스템 응용 (Vision-Based Haptic Interaction Method for Telemanipulation: Macro and Micro Applications)

  • 김정식;김정
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1594-1599
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    • 2008
  • Haptic rendering is a process that provides force feedback during interactions between a user and an object. This paper presents a haptic rendering technique for a telemanipulation system of deformable objects using image processing and physically based modeling techniques. The interaction forces between an instrument driven by a haptic device and a deformable object are inferred in real time based on a continuum mechanics model of the object, which consists of a boundary element model and ${\alpha}$ priori knowledge of the object's mechanical properties. Macro- and micro-scale experimental systems, equipped with a telemanipulation system and a commercial haptic display, were developed and tested using silicone (macro-scale) and zebrafish embryos (micro-scale). The experimental results showed the effectiveness of the algorithm in different scales: two experimental systems applied the same algorithm provided haptic feedback regardless of the system scale.

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