• Title/Summary/Keyword: Abel transformation

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An Experimental Study of Reconstruction from Laser Diffraction Measurement for Axisymmetric Sprays (레이저 회절법을 이용한 축대칭 분무 구조의 공간 분포 변환에 관한 실험적 연구)

  • 양승연;이충훈;구자예;정석호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.1
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    • pp.10-16
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    • 2000
  • Spatially resolved liquid volume fractions from a set of line-of-sight laser diffraction measurements for axisymmetric sprays generated from a pintle-type gasoline injector have been tomographically reconstructed by Abel transformation, Fourier transformation and onion peeling method. Spatially resolved liquid volume fractions classified into 32 size groups were translated characteristics of SI engine fuel sprays. These data were also obtained from the phase Doppler measurements for the same sprays. The comparison between laser deffraction measurements and transformation reconstructs more reasonable spatially resolved characteristics for axisymmetric sprays as well as for asymmetric sprays.

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A Study on Temperature Measurements of Droplet Diffusion Flame using a Two Color Method (이색법을 이용한 액적 확산 화염의 온도 측정에 관한 연구)

  • Lee, Jong-Won;Kim, Youn-Kyu;Park, Seul-Hyun
    • Fire Science and Engineering
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    • v.31 no.4
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    • pp.20-25
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    • 2017
  • In the present study, the temperature distribution of droplet diffusion flames was predicted from the measurements of radiative emissions of soot particles formed. In order to predict the temperature distributions, the radiative emissions from soot particles filtered at both 700 nm and 900 nm were measured using CCD cameras and local emission distributions within the flame deconvoluted with Abel transformation were plugged into a two color method. The experimental results obtained from the present study demonstrate that the two color method as tool for temperature measurements is feasible but can introduce approximately 2% maturement errors in a deconvolution process depending on intervals for the line of sight. The estimated error in temperature measurements was found to be within 18 K at 2000 K.

Discrete Group Method for Nonlinear Heat Equation

  • Darania, Parviz;Ebadian, Ali
    • Kyungpook Mathematical Journal
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    • v.46 no.3
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    • pp.329-336
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    • 2006
  • In the category of the group theoretic methods using invertible discrete group transformation, we give a useful relation between Emden-Fowler equations and nonlinear heat equation. In this paper, by means of appropriate transformations of discrete group analysis, the nonlinear hate equation transformed into the class of the Emden-Fowler equations. This approach shows that, under the group action, the solution of reference equation can be transformed into the solution of the transformed equation.

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Characteristics of Partially Premixed Flames in Double Concentric Burner (이중 동축류 버너에서 부분예혼합화염의 특성에 관한 연구)

  • Kwon, S.J.;Cha, M.S.;Chung, S.H.
    • 한국연소학회:학술대회논문집
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    • 1998.10a
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    • pp.131-138
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    • 1998
  • Flame characteristics in a double concentric burner has been studied experimentally. Air is supplied through a central nozzle, methane/air premixture is supplied in a inner annular part, and coflowing shield air is supplied to minimize outside disturbances. Depending on flow rate and concentration, various flame shapes can be observed. As the flow rate difference between central air jet and annular premixed jet is varied, several distinctive flames are observed. Conditions of partially premixed flames are further investigated; nozzle attached rich premixed flame, inner lifted flame, and outer lifted flame. Using the Abel transformation of digitized images of flames, cross- sectional images of flames can be obtained, from which overall structure of flames can be identified. PLIF measurement of OR radical was also conducted. OR radicals were mainly distributed in diffusion flame region. From the difference of OR distribution between nozzle attached and lifted flames, similarity of OR distribution between tribrachial flame and lifted flames in this study are observed.

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Relationship Between Co-operative Society Governance And Members Satisfaction: A Case Study of the Ambrose Alli University Workers/Farmers Multi-Purpose Cooperative Society, Edo State, Nigeria

  • Ekhorutomwen, Asemota Abel;Peters, Ojeakeri Benson
    • International Journal of Knowledge Content Development & Technology
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    • v.11 no.4
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    • pp.87-99
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    • 2021
  • The study examines the relationship between co-operative society governance and members' satisfaction. Co-operative societies face problems of how to keep balance between efficiency and governance because those in charge of operations of co-operative; the board and the staff must meet two demands i.e. good business practice and the social responsibility which involves the satisfaction of members. The objective of this study is to examine the relationship between co-operative governance and members' satisfaction using Ambrose Alli University Workers/Farmers Multi -Purpose the Co-operative Society as a case study. The data collected in this study were obtained through structured questionnaire. Data analyzed were subjected to descriptive statistics and graphs. The data analyzed indicated that the challenges facing the co-operative society include theft /fraud and mismanagement. Members agitated for transformation of the co-operative society to operate in line with the guidelines of the Central Bank of Nigeria. It was recommended that for efficiency and high productivity, staff should be trained. Also there is need for innovative technology and the necessity for the cooperative society in question to network with other organizations.

Copyright Protection for the Video image with Coded Watermarking (암호화 워터마킹을 사용한 비디오 영상의 저작권 보호)

  • Park, Young;Kim, Hang-Rae;Rhu, Ho-Joon;Kim, Jae-Won
    • Proceedings of the Korea Contents Association Conference
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    • 2003.11a
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    • pp.120-123
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    • 2003
  • In this paper, a digital watermarking scheme whichis effective in protecting a copyright of video image under an image transformation and impulse noise is proposed. The proposing scheme is to use a coded watermark that insert the personal ID of copyrighter. The recovery ability is improved by the coded watermark. Also the coded watermark is abel to trace the illegal distributors. Binary image is used as watermark image, the value of PSNR and recovered rates of watermark are obtained in order to confirm the required invisibility and robustness in watermark system. The experimental results show that image quality is less degraded as the PSNR of 98.21 ㏈. It is also observed that excellent watermark recovery is achieved under the image transformation and impulse noise.

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Analysis of biological functions of rpt-1 in human cells with exposure to environmental pollutants (환경오염물질 폭로에 따른 인체세포에서의 rpt-1 발현 및 역할의 분석)

  • 김선영;양재호
    • Environmental Mutagens and Carcinogens
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    • v.21 no.2
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    • pp.164-168
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    • 2001
  • Abel et al. in Germany discovered a new dioxin-responsive gene, which has later been identified as rpt-1 (regulatory protein T-lymphocyte 1). While it is speculated that rpt-1 may play a role in signal transduction and carcinogenesis, its roles and functions remain unknown. The present study attempted to analyze functions of rpt-1 in human epithelial cells following the xenobiotic exposures. While German counterpart analyzed expressionn of rpt-1 in spleen and thymus cells from mouse and rat and characterizes molecular properties of the gene, our work mainly focused on analyzing function of rpt-1 in human skin cells. Expression of rpt-1 in human cells were analyzed by western and northern blot RT-PCR analysis. Expression of rpt-1 as well as Staf-50 in human cells with or without exposure to environmental pollutants were also analyzed by northern blot analysis, since Staf-50 is homologous with rpt-1 and found in human cells. To help study roles of rpt-1 in human cell system, retroviral vector system carrying rpt-1 gene under the CMV promoter were constructed and transfected. Cells overexpressing the gene after the transfection showed an increase of cell density and soft agar colony formations, as compared to the control cells, suggesting that rpt-1 may play a certain role in the transformation processes of human cells. While the expression of rpt-1 in spleen and thymus is known to be strong in the laboratory animals, both the basal and TCDD-induced expression of rpt-1 in the current cellular system remained insignificant. It is speculated that the expression pattern of rpt-1 may be tissue- and species-specific. The present study demonstrated a strong expression of rpt-1 protein in the brain of SD rat model. Since there is no previous report on the expression of rpt-1 in the brain tissue, the result may play a significant role in understanding dioxin-induced neurotoxicities in the future. The present study provides an opportunity to understand a role of rpt-1 in human cell system and suggest a possible lead and basis for the future study of dioxin-induced neurotoxicities.

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