• Title/Summary/Keyword: Contrast Analysis

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Geological feasibility and slope stability analysis under GIS environment for rail route alignment

  • Jain, Kamal;Kumar, Anand
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.186-188
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    • 2003
  • Rail Route Alignment in hilly terrain is a difficult task to implement as several natural constraints poses threat to the safety and stability of the alignment. The conventional methods followed to find out the final location survey or the feasibility analysis for alignment is time taking consuming. Some times, due to inaccessibility of the terrain it becomes impossible to carry out such works. The construction works in hilly terrain, which are associated with the proposed alignment, are not same as carried out in plane areas due to a vast contrast between the two areas. Different geological structures such as faults, thrusts, synclines and anticlines are a big problem to carry out normal construction practices. Thus for a safe and stable railway route in the unstable hilly areas, it is required to carry out the feasibility analysis of the proposed alignment to assist the policy makers for a successful implementation of the alignment. In the present work Remote Sensing and GIS has been successfully used to carry out geological feasibility and slope stability analysis for rail route alignment work.

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Korea Offshore Seismic Data Processing for Gas Detection (천연 가스 탐지를 위한 국내 대륙붕 탄성파자료 처리)

  • Jang, Seong-Hyung;Sunwoo, Don;Yang, Dong-Woo;Suh, Sang-Young;Chung, Bu-Heung
    • Geophysics and Geophysical Exploration
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    • v.4 no.4
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    • pp.115-123
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    • 2001
  • The bright spot is an indicator for natural gas on seismic stack sections, but it is also shown on layers where the acoustic impedance contrast is large. In order to distinguish sharply between gas and impedance contrast we need additional detailed data processing such as velocity analysis, AVO analysis and seismic complex analysis including measures of seismic amplitude, frequency, and phase. In this study, we performed detailed velocity analysis, complex analysis and DHI (Direct Hydrocarbon Indicator) analysis which is the result of amplitude variation according to the incident angles. The seismic complex analysis gives us the geological information which depends on geophysical properties at the interest layer. For the complex analysis, we computed several seismic attributes such as the instantaneous amplitude, the first and the second derivatives of the instantaneous amplitude, the instantaneous phase, the instantaneous frequency and weighted average instantaneous frequency. Then we applied these analysis techniques to a seismic data of Korea offshore which had been logged. From the result of this data analysis, it could be said that high possibility area for gas layer detection has amplitude anomalies in the instantaneous amplitude, the instantaneous frequency and the DHI section resulting from the AVO analysis. If there are not any other anomalies in detailed data processing, it will have low possibility for gas layer detection.

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NONLINEAR CONTRAST ENHANCEMENT ON SUBTRACTION IMAGES (계수공정영상의 비선형 대조도 증강효과에 관한 연구)

  • Lee Keon-Il;Jin Yeun-Hwa
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.27 no.2
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    • pp.83-90
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    • 1997
  • This study was performed to demonstrate the effect of linear or nonlinear contrast enhancement on subtraction images. Three different textures were radiograped on dental film. The first radiograph was taken without the presence of an object. the second, which showed trabucular bone, was taken of the molar area of a human. the third radiograph was taken of the coronal part of molars. Each film was digitized into a 1312 x 1024 pixel x 8 bit depth matrix by means of a Nikon 35 mm film scanner(LS-3510AF, Japan) with fixed gain and internal dark current correction to maintain constant illumination. The scanner was interfaced to a Macintosh Le ill computer(Apple Computer, Charlotte, N.C) This resulted in three pairs of images, including different textures-plain, bone and enamel. Digital regular, linearly and nonlinearly enhanced subtraction was performed. Computer software was ,used to simulate lesions in the shape of a 2D-Gaussian curve on each of a pair of images. The each subtraction images were presented in a random sequence to two groups of 10 observers(students and dentists). ROC analysis was used to compare observer performance. The following results were obtained ; 1. All of LCE subtraction, equalized subtraction and regular subtraction images of plain texture were diagnosed the best by far. 2. The data revealed a siginificant LCE effect in both the student group and the expert group. 3. Clinical expertise was a helphul factor for the observers in this study.

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Automated radiation field edge detection in portal image using optimal threshold value (최적 문턱치 설정을 이용한 포탈영상에서의 자동 에지탐지 기법에 관한 연구)

  • 허수진
    • Journal of Biomedical Engineering Research
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    • v.16 no.3
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    • pp.337-344
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    • 1995
  • Because of the high energy of the treatment beam, contrast of portal films is very poor. Many image processing techniques have been applied to the portal images but a significant drawback is the loss of definition on the edges of the treatment field. Analysis of this problem shows that it may be remedied by separating the treatment field from the background prior to enhancement and uslng only the pixels within the field boundary in the enhancement procedure. A new edge extraction algorithm for accurate extraction of the radiation field boundary from portal Images has been developed for contrast enhancement of portal images. In this paper, portal image segmentation algorithm based on Sobel filtration, labelling processes and morphological thinning has been presented. This algorithm could automatically search the optimal threshold value which is sensitive to the variation of the type and quality of portal images.

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A Comparative Study on the Self-help Approach in Rural Development between Vietnam's New Rural Development and Korea's Saemaul Undong

  • Do, Trang Thu;Nguyen, Hanh Thi My;Vu, Trang Thu
    • East Asian Economic Review
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    • v.20 no.1
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    • pp.91-125
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    • 2016
  • Vietnam's "Doi Moi", initiated in 1986, translated to high economic growth and rapid urbanization for the country, but also widened the gap between rural and urban areas. Vietnam's National Target Program on New Rural Development for 2010-2020 was aimed at developing the rural economy and improving the living standards of rural people, but after five years the urban-rural gap remains substantial. Two of the main reasons are the lack of investment capital and lack of effective ways to mobilize community involvement. In contrast, during the 1970s, rural areas in Korea experienced huge improvements under the "Saemaul Undong" movement. The program's success at promoting sustainable development in Korea's rural areas has inspired rural programs in other developing countries. In this paper, we compare and contrast the two movements to provide explanations for the different results between the two countries. Based on this analysis, and policy implications stemming from it, we recommend resource mobilization strategies to change villagers' attitude and increase their involvement in Vietnam's rural development movement, aligning with the inclusivity principle "people know, people discuss, people do and people check".

The Impact of Earnings Quality on Firm Value: The Case of Vietnam

  • DANG, Hung Ngoc;NGUYEN, Thi Thu Cuc;TRAN, Dung Manh
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.3
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    • pp.63-72
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    • 2020
  • The study aims to investigate the impact level of earnings quality on firm value. The study has used data with 3,910 observations at listed firms on Vietnam Stock Exchange for the period from 2010 to 2018, and GLS regression analysis is employed in this research. Earnings quality is measured in the aspects of earnings management, earnings persistence, and timeliness of profitability. This study also considers a number of controlled variables that positively influence the firm's value such as firm size, fixed asset investment rate and dividend payout ratio. The results show that earnings quality is positively associated with firm value with having statistical significance. In contrast, some determinants negatively influence firm value such as financial leverage, ratio of market value to book value, and revenue growth. Determinants of firm size, the rate of investment in fixed assets, the rate of dividend payment positively affect the firm value. In contrast, determinants of financial leverage, revenue growth rate and market value to book value ratio are inversely related to firm value according to economic value, Tobin's Q or Price. Based on the findings, some recommendations are proposed for investors, management and policy makers as well in the context of emerging countries including Vietnam.

The Analysis of Gravity Mura Induced in Patterned Spacer Color Filter on Large Size LCD (대 면적 LCD에서 Patterned Spacer Color Filter 사용 시 발생하는 중력무라 분석)

  • Choi, S.;Jeong, Y.H.;Kim, M.S.;Kim, G.H.;Kim, H.Y.;Kim, S.Y.;Lim, Y.G.
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.8
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    • pp.871-874
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    • 2004
  • In recent, it is said that the trend of LCD is direction to pursue high qualities like as high transmittance, high contrast ratio, wide viewing angle, fast response time, and so on. Especially, it is known that these qualities are essential to large size LCD like as LCD TV and we can realize them through to uniform cell gap and deep black state. Until now, the ball spacer has been used to control of uniform cell gap. However, the existence of ball spacer inside the cell causes the deformation of the liquid crystal molecules and damage to alignment layer. Such a deformation of the liquid crystal causes light-leakage in the dark state, which lowers contrast ratio of the display. Nowadays, this problem has been solved by using Patterned Spacer on Color Filter. but Side Effect just as gravity mura has been induced. In this paper, we studied the mechanism on gravity mura in case of using patterned spacer on color filter.

Feature values of DWT using MR general imaging and molecular imaging (DWT를 이용한 MR 일반영상과 분자영상 특징추출)

  • Pack, Dae-Sung;Choi, Gui-Rack;Han, Byung-Sung;Ahn, Byung-Ju
    • Journal of the Korean Society of Radiology
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    • v.6 no.5
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    • pp.409-414
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    • 2012
  • This study acquired molecular lmaging using nano-contrast agents, and the general condition of the same image acquisition to analyze the difference between molecular imaging and general imaging, two images are converted into DWT (Discrete Wavelet Transform). Nano-contrast agent imaging using MRI and molecular imaging using PET study of molecular imaging technology mainstream. DWT analysis of the same lesions using MRI imaging and molecular imaging block lesions are present in the lesions, illustrating the value of a high-frequency feature both highly general imaging and molecular imaging could know that. The high frequency region of the feature extraction values appear higher molecular imaging.

Analysis of Mathematical Quality of Instruction between Preservice and Inservice Mathematics Teachers (MQI를 이용한 예비교사와 현직교사의 수학수업의 질 분석)

  • Kim, Seong-Kyeong
    • The Mathematical Education
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    • v.55 no.4
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    • pp.397-416
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    • 2016
  • This study analyzed the quality of mathematics classes with observations using the instrument, MQI(Mathematical Quality of Instruction). Class recordings and interviews were conducted on 2 pre-service teachers and 4 in-service teachers. This study recorded and analyzed 3 or 4 classes for each mathematics teacher by using revised MQI. There were a total of 8 raters: 2 or 3 raters analyzed each class. MQI has four dimensions: Richness of the Mathematics, Working with Students and Mathematic, Errors and Imprecision, Student Participation in Meaning-Making and Reasoning. In the dimension of 'Richness of Mathematics', all teachers had good scores of 'explanations of teacher' but had lower scores of 'linking and connections', 'multiple procedures or solution methods' and 'developing mathematical generalizations.' In the dimension of 'Working with Students and Mathematics', two in-service teachers who have worked and having more experience had higher scores than others. In the dimension of 'Errors and Imprecision', all teachers had high scores. In the dimension of 'Student Participation in Meaning-Making and Reasoning', two pre-service teachers had contrast and also two in-service teachers who hadn't worked not long had contrast. Implications were deducted from finding to improving quality of mathematics classes.

A Review of IWFR Method for HRTEM Image Analysis and Application (HRTEM영상 분석에 대한 IWFR 방법의 고찰 및 응용)

  • Kim, Hwang-Su
    • Applied Microscopy
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    • v.38 no.1
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    • pp.63-72
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    • 2008
  • The iterative wave-function reconstruction (IWFR) method developed by Allen et al. (2004) was reviewed with concern for its applicability. The high resolution transmission electron microscopy (HRTEM) studies of the materials such as GaAs, $YBa_2Cu_3O_7$ and $Al_2CuMg$ reported in the literature were utilized in this review. In this process the basis of validity, the limiting conditions and the information limit of this method were discussed. It was particularly noted that the phase contrast image of the exit plane wave evaluated from this method reveals not only $C_s$-corrected atomic resolution within information limit, but also strong tendency of contrast proportional to the magnitude of the atomic number of compositional atoms in a crystal.