• Title/Summary/Keyword: Intensity transformation

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Mechanical Behavior of Fiber Metal Laminates with Local Delamination Defects (국부적 적층분리결함을 갖는 섬유금속적층판의 기계적 거동 특성)

  • Choi, Heungsoap;Choi, Hyungjip;Choi, Wonjong;Ha, Minsu
    • Journal of Aerospace System Engineering
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    • v.1 no.1
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    • pp.25-35
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    • 2007
  • In this paper, the interlaminar crack problems of a fiber metal laminate (FML) under generalized plane deformation are studied using the theory of anisotropic elasticity. The crack is considered to be embedded in the matrix interlaminar region (including adhesive zone and resin rich zone) of the FML. Based on Fourier integral transformation and the stress matrix formulation, the current mixed boundary value problem is reduced to solving a system of Cauchy-type singular integral equations of the 1st kind. Within the theory of linear fracture mechanics, the stress intensity factors are defined on terms of the solutions of integral equations and numerical results are obtained for in-plane normal (mode I) crack surface loading. The effects of location and length of crack in the 3/2 and 2/1 ARALL, GLARE or CARE type FML's on the stress intensity factors are illustrated.

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100W급 LED 보완가로등 직하조도 최적화를 위한 LightTools Simulation 분석

  • Sin, Ik-Tae;Jo, Ju-Ung;Yang, Jong-Gyeong;Park, Dae-Hui
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.164-164
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    • 2009
  • This paper had analyzed property of LED chip which has appropriate distribution and had designed modeling in order to experiment optical property of LED module through simulation. also throughout error value between street light and simulation data, precisive simulation could be inferred. as a consequent, transformation of optical property had henceforth verified the first value of module array.

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Vibration Power Flow Analysis of Coupled Shell Structures (연성된 쉘 구조물의 진동 파워흐름해석)

  • Kim, Il-Hwan;Hong, Suk-Yoon;Park, Do-Hyun;Kil, Hyun-Gwon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.352.2-352
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    • 2002
  • In this paper, Power Flow Analysis (PFA) method has been applied to the prediction of vibration energy density and intensity of coupled shell structures in the medium-to-high frequency ranges. To consider the wave transformation at joint between shell elements, power transmission and reflection coefficients are investigated for various joint angles, and here Donnell-Mushtari thin shell theory has been used. (omitted)

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DWIT and CF Methods for Automated Target Search on Aerial Images (항공 영상의 자동 표적 탐색을 위한 DWIT와 CF 기법)

  • 유채곤;이성환;이원호;황치정
    • Proceedings of the Korean Information Science Society Conference
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    • 1998.10c
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    • pp.559-561
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    • 1998
  • 항공영상이나 위성영상을 이용하는 원격 감지 기술(Remote Sensing)은 무인 비행, 지리 정보 시스템(GIS) 그리고 도시 계획에 이용되고 있다. 원격 감지 기술과 함께 사용될 수 있는 또 하나의 기술로는 자동 표적 탐색 기술이 있으며 현재 많은 연구가 진행되고 있으나, 대부분 특정적인 시험용 영상에만 적용되고 있어서 항공 영상과 같이 복잡하고 불규칙적인 경우에는 적용이 어렵다. 본 논문에서는 Distance Weighted Intensity Transformation (DWIT)와 Coefficients Filtering(CF) 방법을 이용하여 영상의 이동, 회전, 배경에 불변적인 항공 영상 표적 탐색 기법을 제안한다.

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Automated Prostate Cancer Detection on Multi-parametric MR imaging via Texture Analysis (다중 파라메터 MR 영상에서 텍스처 분석을 통한 자동 전립선암 검출)

  • Kim, YoungGi;Jung, Julip;Hong, Helen;Hwang, Sung Il
    • Journal of Korea Multimedia Society
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    • v.19 no.4
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    • pp.736-746
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    • 2016
  • In this paper, we propose an automatic prostate cancer detection method using position, signal intensity and texture feature based on SVM in multi-parametric MR images. First, to align the prostate on DWI and ADC map to T2wMR, the transformation parameters of DWI are estimated by normalized mutual information-based rigid registration. Then, to normalize the signal intensity range among inter-patient images, histogram stretching is performed. Second, to detect prostate cancer areas in T2wMR, SVM classification with position, signal intensity and texture features was performed on T2wMR, DWI and ADC map. Our feature classification using multi-parametric MR imaging can improve the prostate cancer detection rate on T2wMR.

Deep Learning: High-quality Imaging through Multicore Fiber

  • Wu, Liqing;Zhao, Jun;Zhang, Minghai;Zhang, Yanzhu;Wang, Xiaoyan;Chen, Ziyang;Pu, Jixiong
    • Current Optics and Photonics
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    • v.4 no.4
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    • pp.286-292
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    • 2020
  • Imaging through multicore fiber (MCF) is of great significance in the biomedical domain. Although several techniques have been developed to image an object from a signal passing through MCF, these methods are strongly dependent on the surroundings, such as vibration and the temperature fluctuation of the fiber's environment. In this paper, we apply a new, strong technique called deep learning to reconstruct the phase image through a MCF in which each core is multimode. To evaluate the network, we employ the binary cross-entropy as the loss function of a convolutional neural network (CNN) with improved U-net structure. The high-quality reconstruction of input objects upon spatial light modulation (SLM) can be realized from the speckle patterns of intensity that contain the information about the objects. Moreover, we study the effect of MCF length on image recovery. It is shown that the shorter the fiber, the better the imaging quality. Based on our findings, MCF may have applications in fields such as endoscopic imaging and optical communication.

Method of Estimating the Ground-Motion Intensity Measures at a Nearby Site by using the Time-domain Transformation of Site Response (지진파형의 시간영역 부지응답특성 변환을 통한 인접부지의 지진동세기 추정 방법)

  • Yun, Kwan-Hee;Park, Dong-Hee
    • Geophysics and Geophysical Exploration
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    • v.13 no.3
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    • pp.219-226
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    • 2010
  • Current earthquake alert notification for immediate post-earthquake procedures for the critical facilities is exclusively dependent on the ground-motion intensity measures observed at the seismic station located within the site. This practice is prune to false notification due to a noise and problems of missing and poor quality records of the seismic station. The credibility of the earthquake alert notification can be enhanced by utilizing the multiple transformed records of the nearby seismic stations at other sites interconnected to the same earthquake monitoring system by a network. The time-domain transformation of the site-response between the seismic stations is implemented by convoluting the nearby records with a pair of forward and inverse FIR filters designed for the site response relative to a seismic basement. The transformed records from the nearby seismic stations can be used to estimate the ground-motion intensity measures missing at the site or to evaluate the data quality along with other various possible applications in the area of geoscience and earthquake engineering.

Normalization of Spectral Magnitude and Cepstral Transformation for Compensation of Lombard Effect (롬바드 효과의 보정을 위한 스펙트럼 크기의 정규화와 켑스트럼 변환)

  • Chi, Sang-Mun;Oh, Yung-Hwan
    • The Journal of the Acoustical Society of Korea
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    • v.15 no.4
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    • pp.83-92
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    • 1996
  • This paper describes Lombard effect compensation and noise suppression so as to reduce speech recognition error in noisy environments. Lombard effect is represented by the variation of spectral envelope of energy normalized word and the variation of overall vocal intensity. The variation of spectral envelope can be compensated by linear transformation in cepstral domain. The variation of vocal intensity is canceled by spectral magnitude normalization. Spectral subtraction is use to suppress noise contamination, and band-pass filtering is used to emphasize dynamic features. To understand Lombard effect and verify the effectiveness of the proposed method, speech data are collected in simulated noisy environments. Recognition experiments were conducted with contamination by noise from automobile cabins, an exhibition hall, telephone booths in down town, crowded streets, and computer rooms. From the experiments, the effectiveness of the proposed method has been confirmed.

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Lane Detection Algorithm for Night-time Digital Image Based on Distribution Feature of Boundary Pixels

  • You, Feng;Zhang, Ronghui;Zhong, Lingshu;Wang, Haiwei;Xu, Jianmin
    • Journal of the Optical Society of Korea
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    • v.17 no.2
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    • pp.188-199
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    • 2013
  • This paper presents a novel algorithm for nighttime detection of the lane markers painted on a road at night. First of all, the proposed algorithm uses neighborhood average filtering, 8-directional Sobel operator and thresholding segmentation based on OTSU's to handle raw lane images taken from a digital CCD camera. Secondly, combining intensity map and gradient map, we analyze the distribution features of pixels on boundaries of lanes in the nighttime and construct 4 feature sets for these points, which are helpful to supply with sufficient data related to lane boundaries to detect lane markers much more robustly. Then, the searching method in multiple directions- horizontal, vertical and diagonal directions, is conducted to eliminate the noise points on lane boundaries. Adapted Hough transformation is utilized to obtain the feature parameters related to the lane edge. The proposed algorithm can not only significantly improve detection performance for the lane marker, but it requires less computational power. Finally, the algorithm is proved to be reliable and robust in lane detection in a nighttime scenario.

The analysis of drought susceptibility using soil moisture information and spatial factors involved in satellite imagery (위성영상의 토양수분 정보와 공간적 요인을 고려한 가뭄 민감도 분석)

  • 박은주;황철수;성정창
    • Spatial Information Research
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    • v.10 no.3
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    • pp.481-492
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    • 2002
  • The severity and spatial Patterns of spring drought on the croplands arc investigated using satellite imagery(Landsat ETM+). It is necessary to analyze the area droughty conditions in order to decrease the damage and make the efficient policies. In this context, the information about soil moisture levels, which were fatal factors to the crop growth, was acquired from wetness calculated from Tasseled cap transformation. We confirmed that the wetness values have a strong correlation with NDVI and the principal components. The result showed that the intensity of vegetation covering the surface could be understood as the index of the impacts of drought on croplands and these relationships were effective to classify dry areas in satellite imagery.

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