• 한국건축시공학회지
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• 제20권4호
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• pp.339-345
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• 2020

본 연구는 매년 수만 건 발생되는 화재에서 화재확산에 의한 피해 예방과 대응 마련을 위해 공동주택 및 일반건물의 내부화재를 실물화재실험을 통해 재현하였다. 또한, 개구부 크기와 차양길이 조건을 달리하고 이에 따른 외벽온도 분포를 분석하여 화재확산방지 기초자료를 제공하고자 하였다. 실험결과, 차양을 설치하지 않았을 때 최고온도는 약 380℃ 이상으로 나타났다. 차양을 설치하지 않은 최고온도를 기준으로 차양길이가 150mm 일 때, 동일한 측정점에서 약 90℃가량 낮아졌으며, 300mm에서 약 150℃ 이상, 450mm에서 175℃ 이상 온도가 낮아졌으며, 차양길이 600mm 일 때, 최고온도 차는 약 180℃ 이상 낮아지는 것으로 나타나 개구부 상부의 차양 설치가 외벽의 수직화재 확산에 의한 화염온도를 낮추는데 효과가 있는 것으로 판단된다.

• 한국지형학회지
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• 제19권4호
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• pp.13-25
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• 2012

본 연구의 목적은 사행하는 자연하천에서의 이차류 특성을 실험적으로 관측하는 것이다. 이를 위하여 사행도가 1.2인 실규모 실험수로에서 다양한 유량 및 수심조건을 재현하고 3차원 유속 및 수심측정을 수행하였다. 실험결과, 만곡부의 외측에서 최대 유속이 관측되는 강한 이차류의 특성이 관측되었다. 이는 수직벽을 가지는 소규모 실험실 실험의 결과와 다른 양상으로 자연하천의 형태에 가까운 1:2 하안과 넓은 수면폭을 가지는 본 연구의 실험시설이 보이는 특성으로 이해된다. 만곡부의 외측에 발생하는 최대유속은 직선부로 진행됨에 따라 유심선 근처로 이동하여 직선형 하도에서의 흐름특성과 유사한 형태로 변화하였다. 이와 함께 양안에 각각 회전류가 형성되어 2개의 이차류가 발생하는 현상 역시 관측되었다.

• 제어로봇시스템학회논문지
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• 제10권5호
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• pp.415-420
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• 2004

We present a new algorithm for the calibration of a camera and the recovery of 3D scene structure up to a scale from image sequences using known angles between lines in the scene. Traditional method for calibration using scene constraints requires various scene constraints due to the stratified approach. Proposed method requires only one type of scene constraint of known angle and also it directly recovers metric structure up to an unknown scale from projective structure. Specifically, we recover the matrix that is the homography between the projective structure and the Euclidean structure using angles. Since this matrix is a unique one in the given set of image sequences, we can easily deal with the problem of varying intrinsic parameters of the camera. Experimental results on the synthetic and real images demonstrate the feasibility of the proposed algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권2호
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• pp.662-675
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• 2018

Compression history detection plays an important role in digital multimedia forensics. Most existing works, however, mainly focus on digital image and video. Additionally, the existed audio compression detection algorithms aim to detect the trace of double compression. In real forgery scenario, multiple compression is more likely to happen. In this paper, we proposed a detection algorithm to reveal the compression history for MP3 audio. The statistics of the scale factor and Huffman table index which are the parameters of MP3 codec have been extracted as the detecting features. The experimental results have shown that the proposed method can effectively identify whether the testing audio has been previously treated with single/double/triple compression.

• 한국자동차공학회논문집
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• 제9권5호
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• pp.195-205
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• 2001

The mechanical properties of aluminum honeycomb on the direction of axial crushing under quasistatic loading test was investigated. The crushing process was simulated numerically by full-scale finite element models. Simulations reproduce the experimental results both qualitatively as well as quantitatively. From the investigation, we suggested the constitutive model of energy absorbing honeycomb structure for large scale impact analysis. Real impact test of the WB(Moving Deformable Barrier) was carried and compared with finite element simulation. Constitutive model used in the numerical simulation had a good correlation with experiment. By suggesting the optimizing method fur honeycomb cell configuration design, relationship between cell configuration and crush strength is studied.

• Wind and Structures
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• 제21권6호
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• pp.709-726
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• 2015

In this study, a novel vision-based bolt-loosening monitoring technique is proposed for bolted joints connecting tubular steel segments of the wind turbine tower (WTT) structure. Firstly, a bolt-loosening detection algorithm based on image processing techniques is developed. The algorithm consists of five steps: image acquisition, segmentation of each nut, line detection of each nut, nut angle estimation, and bolt-loosening detection. Secondly, experimental tests are conducted on a lab-scale bolted joint model under various bolt-loosening scenarios. The bolted joint model, which is consisted of a ring flange and 32 sets of bolt and nut, is used for simulating the real bolted joint connecting steel tower segments in the WTT. Finally, the feasibility of the proposed vision-based technique is evaluated by bolt-loosening monitoring in the lab-scale bolted joint model.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권12호
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• pp.2374-2391
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• 2011

A variety of reconstruction methods has been developed to convert a set of scattered points generated from real models into explicit forms, such as polygonal meshes, parametric or implicit surfaces. In this paper, we present a method to construct multi-scale implicit surfaces from scattered points using multiscale kernels based on kernel and multi-resolution analysis theories. Our approach differs from other methods in that multi-scale reconstruction can be done without additional manipulation on input data, calculated functions support level of detail representation, and it can be naturally expanded for n-dimensional data. The method also works well with point-sets that are noisy or not uniformly distributed. We show features and performances of the proposed method via experimental results for various data sets.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.193-196
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• 2008

In these days, large structures are constructed and bonded with ground grid Because the distances between mesh and auxiliary electrodes are not enough in downtown areas, it is very difficult to measure the ground resistance of large scale grounding electrode systems. Actually the auxiliary electrodes for test are installed in grounding grid. This paper present the experimental results of ground resistance and impedance according to the location of auxiliary electrode. As a result, we get much lower resistances and impedances than real values the auxiliary electrodes are placed in the ground grid. In case that the auxiliary electrodes are located in the ground grid the resistances are very low and reactance only is inductive component.

• Journal of Electrical Engineering and Technology
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• 제9권5호
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• pp.1712-1718
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• 2014

Experimental analysis according to the plasma actuator design variables was performed in order to verify the effects of sliding discharge plasma on aerodynamic drag reduction of a high-speed train. For the study, sliding discharge plasma actuator and high-frequency, high-voltage power supply were developed and experimented to figure out the best design variables for highest ionic wind velocity which could reduce the drag force. And then, 5% reduced-scale model of a high-speed train was built for wind tunnel test to verify it. From the results, it was confirmed that sliding discharge plasma had contribution to reduce the drag force and it had the potential to be applied to real-scale trains.

• Journal of Preventive Medicine and Public Health
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• 제35권2호
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• pp.83-91
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• 2002

Bioinformatics is a rapidly emerging field of biomedical research. A flood of large-scale genomic and postgenomic data means that many of the challenges in biomedical research are now challenges in computational sciences. Clinical informatics has long developed methodologies to improve biomedical research and clinical care by integrating experimental and clinical information systems. The informatics revolutions both in bioinformatics and clinical informatics will eventually change the current practice of medicine, including diagnostics, therapeutics, and prognostics. Postgenome informatics, powered by high throughput technologies and genomic-scale databases, is likely to transform our biomedical understanding forever much the same way that biochemistry did a generation ago. The paper describes how these technologies will impact biomedical research and clinical care, emphasizing recent advances in biochip-based functional genomics and proteomics. Basic data preprocessing with normalization, primary pattern analysis, and machine learning algorithms will be presented. Use of integrated biochip informatics technologies, text mining of factual and literature databases, and integrated management of biomolecular databases will be discussed. Each step will be given with real examples in the context of clinical relevance. Issues of linking molecular genotype and clinical phenotype information will be discussed.