• Title/Summary/Keyword: Intensity transformation

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Experiment for 3D Coregistration between Scanned Point Clouds of Building using Intensity and Distance Images (강도영상과 거리영상에 의한 건물 스캐닝 점군간 3차원 정합 실험)

  • Jeon, Min-Cheol;Eo, Yang-Dam;Han, Dong-Yeob;Kang, Nam-Gi;Pyeon, Mu-Wook
    • Korean Journal of Remote Sensing
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    • v.26 no.1
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    • pp.39-45
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    • 2010
  • This study used the keypoint observed simultaneously on two images and on twodimensional intensity image data, which was obtained along with the two point clouds data that were approached for automatic focus among points on terrestrial LiDAR data, and selected matching point through SIFT algorithm. Also, for matching error diploid, RANSAC algorithm was applied to improve the accuracy of focus. As calculating the degree of three-dimensional rotating transformation, which is the transformation-type parameters between two points, and also the moving amounts of vertical/horizontal, the result was compared with the existing result by hand. As testing the building of College of Science at Konkuk University, the difference of the transformation parameters between the one through automatic matching and the one by hand showed 0.011m, 0.008m, and 0.052m in X, Y, Z directions, which concluded to be used as the data for automatic focus.

A Comparative Study of Optimal Stretch Intensity For Flexibility of Hamstrings; Hand Held Dynamometer and Verbal Rating Scale

  • Choi, Bong-sam
    • Physical Therapy Korea
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    • v.24 no.4
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    • pp.38-45
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    • 2017
  • Background: To improve muscle flexibility, static stretch is the most common type and is considered safe and effective for improving overall flexibility of muscles. During the stretch, the intensity is more likely to be determined by the degree of an athlete's pain and practitioner's skills rather than quantitative measures of stretch. It is necessary to determine the optimal intensity for the stretch. Objects: The purpose of this study is to explore the relationship between hand held dynamometer (HHD) and verbal rating scale (VRS) in comparison of the effects of continuance time on active (walking) and inactive (sitting) movement after static stretch. Methods: A cross-sectional study was conducted with a sample (n=62) recruited from a university. Participants were randomly assigned to 2 different groups (n=31 for each group) based on participants' positions either remaining in sitting or freely walking around for a series of re-assessments. Data was collected at pre-warm up, pre-stretch, post-stretch, and additional assessments at the time of 3, 6, 9, 12, 15, 20 and 30 minutes after the stretch. Results: Relationship between VRS and HHD scores represents very weak correlation (Spearman's p=-.16, p>.05). Pearson's correlation analysis was conducted following the logarithmic transformation of the two scores. Pearson's correlation after the transformation still showed a very low relationship and a poor linear relationship between the two scores (Pearson's r=-.18, p>.05). Conclusion: The optimal intensity for stretch cannot be solely determined by the subjective pain perception. The objective measurement such as HHD could be used in conjunction with the pain perception.

Single Image Dehazing Using Linear Transformation of Saturation (채도의 선형 변환을 이용한 단일 영상 안개 제거)

  • Park, Taehee
    • IEMEK Journal of Embedded Systems and Applications
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    • v.14 no.4
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    • pp.197-205
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    • 2019
  • In this paper, an efficient single dehazing algorithm is proposed based on linear transformation by assuming that a linear relationship exists in saturation component between the haze image and haze-free image. First, we analyze the linearity of saturation channel, estimate the medium transmission map in terms of the saturation component. Then, the intensity of haze-free image is assumed by using CLAHE to enhance contrast of haze image. Experimental results demonstrate that proposed algorithm can naturally recover the image, especially can remove color distortion caused by conventional methods. Therefore, our approach is competitive with other state-of-the art single dehazing methods.

Magneto-optical and optical properties of Fe-Au alloy films in a wide composition range

  • Hyun, Y.H.;Kim, C.O.;Lee, Y.P.;Kudryavtsev, Y.V.;Gontarz, R.;Kim, K.W.
    • Journal of Korean Vacuum Science & Technology
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    • v.5 no.2
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    • pp.43-46
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    • 2001
  • Fe-Au alloys are characterized by the complete solubility, and exhibit an fcc-bcc structural transformation at the Fe-rich side. The magneto-optical(equatorial Ken effect : EKE) and optical properties of Fe$\_$1-x/Aux (0 < x < 1) were investigated in the 0.5 - 5.0 eV energy range. The x-ray diffraction study shows the structural fcc-bcc transformation about 80 at. % of Fe. Noticeable changes in the optical properties caused by the fcc-bcc structural transformation was observed. The shape and intensity of the EKE spectra as well as the field dependence of the magneto-optical response were also significantly changed. It is thought that these changes are mainly comes from the induced magnetic moment in Au(and/or the emhanced magnetic moment of Fe). The nature of the prominent structure observed in the UV range of the magneto-optical Ken effect of Au/Fe multilayered films are disscussed in connection with the above results.

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A Study on Estimation of Residual Stress in Carburized Spur Gears and Its Effect on the Stress Intensity Factor (침탄치차의 잔류응력추정 및 잔류응력을 고려한 응력확대계수에 관한 연구)

  • 류성기
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.30-37
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    • 1997
  • This paper deals with the residual stress of carburized spur gears is calculated being on the assumption that the main cause of residual stress is the volume difference between case and core due to the martensitic transformation in cooling. A formula is proposed to estimated the residual stress from the hardness and the amount of retained austenite. The estimated residual stress is close to the stress measured by X-ray method. The estimated residual stress is applied to the analysis of the fracture mechanics of carburized spur gear teeth. The stress intensity factor due to the residual stress is demonstrated. The stress intensity factor is computed by the influence function method, and it is shown that the factor is decreased by the residual stress in Carburized gear tooth.

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IKONOS Image Fusion Using a Fast Intensity-Hue-Saturation Fusion Technique (빠른 IHS 기법을 이용한 IKONOS 영상융합)

  • Yun, Kong-Hyun
    • Journal of Korean Society for Geospatial Information Science
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    • v.14 no.1 s.35
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    • pp.21-27
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    • 2006
  • Among various image fusion methods, intensity-hue-saturation(IHS) technique is capable of quickly merging the massive volumes of data. For IKONOS imagery, IHS can yield satisfactory 'spatial' enhancement but may introduce 'spectral' distortion, appearing as a change in colors between compositions of resampled and fused multispectral bands. To solve this problem a fast IHS fusion technique with spectral adjustment is presented. The experimental results demonstrate that the proposed approach can provide better performance than the conventional IHS method, in both processing speed and image quality.

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Application of the modified fast fourier transformation weighted with refractive index dispersion far an accurate determination of film thickness (굴절률 분산을 반영한 고속 푸리에 변환 및 막두께 정밀결정)

  • 김상준;김상열
    • Korean Journal of Optics and Photonics
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    • v.14 no.3
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    • pp.266-271
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    • 2003
  • The reflectance spectrum of optical films thicker than a few microns shows an intensity oscillation due to interference. Since the spectral period of the oscillation is inversely related to film thickness, the thickness of an optical film can be determined from the spectral frequency of the oscillation. For rapid data processing, the spectral frequency is obtained by use of a Fast Fourier Transformation technique. The conventional method of applying a Fast Fourier Transformation to the reflectance spectrum versus photon energy is modified so as to clear the ambiguity in choosing the proper effective refractive index value and to prevent the broadening of the Fourier transformed peak due to the refractive index dispersion. This technique of modified Fast Fourier Transformation is suggested by the authors for the first time to their knowledge. From the analysis of the calculated reflectance spectrum of a 30-${\mu}{\textrm}{m}$-thick dielectric film. it is shown to improve the accuracy in determining film thickness by a great amount. The improved accuracy of the modified Fast Fourier Transformation is also confirmed from the analysis of the reflectance spectra of a sample with 80-${\mu}{\textrm}{m}$-thick cover layer and 13-${\mu}{\textrm}{m}$-thick spacer layer on a PC substrate.

A Study on the Prediction of Shrinkage and Residual Stress for the HY-100 Weldment Considering the Phase Transformation (상 변태를 고려한 HY-100강 용접부의 수축 및 잔류응력 예측에 관한 연구)

  • Lee, Hee-Tae;Shin, Sang-Beom
    • Journal of Welding and Joining
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    • v.25 no.1
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    • pp.42-48
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    • 2007
  • For high performance and structural stability, application of high strength steel has continuously increased. However, the change of the base metal gives rise to problems with the accuracy management of the welded structure. It is attributed to the martensite phase transformation of the high strength low alloy steel weldment. The purpose of this study is to establish the predictive equation of transverse shrinkage and residual stress for the HY-100 weldment. In order to do it, high speed quenching dilatometer tests were performed to define a coefficient of thermal expansion(CTE) at the heating and cooling stage of HY-100 with various cooling rates. Uncoupled thermal-mechanical finite element(FE) models with CTE were proposed to evaluate the effect of the martensite phase transformation on transverse shrinkage and residual stresses at the weldment. FEA results were verified by comparing with experimental results. Based on the results of extensive FEA and experiments, the predictive equation of transverse shrinkage and longitudinal shrinkage force at the HY-100 weldment were formulated as the function of welding heat input/in-plane rigidity and welding heat input respectively.

A Practical Approach Determining an IDF formula with Limited Rainfall-Duration Data Availability (제한적 강우-지속기간 자료를 이용한 실용적 IDF 관계식의 유도)

  • Seong, Kee-Won
    • Journal of Korea Water Resources Association
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    • v.41 no.6
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    • pp.587-595
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    • 2008
  • In order to aid the derivation of the IDF relationship for a station with insufficient duration-rainfall data, an approach to derive a simple and practical IDF formula is presented. The IDF formula is described simply by the term of the two parameters and a design frequency. The model parameters were estimated from a statistical technique based on the normal distribution of transformed rainfall intensities. In order to give the transformed data, both the Kruskal-Wallis statistic and the Manly transformation of duration-rainfall data were adopted. With the methods, the proposed IDF formula becomes a simpler model that compares well with conventional form. In addition, it allows avoiding an exceptional condition of the higher rainfall intensity for longer duration. The performance of the proposed formula was evaluated by using the limited rainfall data for short duration from two gauge stations. The result showed that the IDF formula developed in this work was an effective tool, providing a reliable relationship between the intensity and duration even though insufficient data are only available.