• 제목/요약/키워드: U.J.S.

검색결과 1,685건 처리시간 0.039초

The Measures of Ozone Pollution: An Analysis of Ozone Concentration Data in USA

  • Kim, Hong-J.;Lovell, Sabrina J.;O'Farrell, John;Cho, Yong-Sung
    • Asian Journal of Atmospheric Environment
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    • 제2권1호
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    • pp.47-53
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    • 2008

  • In this study, we analyzed how ozone pollution could be differently measured and how these different measures varied year to year and across the ten most populated cities in the United States, from 1980 to 2000. Although peak values of ozone concentration have been significantly reduced in most polluted U.S. cities for the last 20 years, the annual average values of ozone concentration have not been lowered as much as peak values. Ozone concentration data for each city shows a unique pattern of distribution, central tendency, and also there is a wide variation among different ozone measures. Two different cities with the same annual mean concentration of ozone can experience very different distributions of ozone concentration within a year. Ozone measures also show a wide margin of variability as they are estimated from different ozone monitoring sites within each city. Ozone pollution statistics can be largely varied depending on the choice of measures, monitoring sites, and averaging time period. EPA's new ozone standard of 0.08 ppm averaged over an eight-hour appears to be more stringent than the current maximum ozone standard of 0.12 ppm averaged over one hour.

  • https://doi.org/10.5572/ajae.2008.2.1.047 인용 PDF

Enhancement of Optical Performance by Light Diffusion Films

  • Seo, M.S.;Yoon, J.S.;Heo, J.U.;Kim, S.S.;Moon, C.W.
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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    • pp.1262-1265
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    • 2004

  • To increase the performance of the light diffusion films, we controlled the three dimensional microstructure of the organic fillers(beads). The refractive index, the size distribution and the three dimensional distribution of beads play an important role to determine the performance of light diffusion films for the backlight unit of TFT-LCD.

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WEAK CONVERGENCE THEOREMS FOR ALMOST-ORBITS OF AN ASYMPTOTICALLY NONEXPANSIVE SEMIGROUP IN BANACH SPACES

  • Kim, J.K.;Nam, Y.M.;Jin, B.J.
    • 대한수학회논문집
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    • 제13권3호
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    • pp.501-513
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    • 1998

  • In this paper, we deal with the asymptotic behavior for the almost-orbits {u(t)} of an asymptotically nonexpansive semigroup S = {S(t) : t $\in$ G} for a right reversible semitopological semigroup G, defined on a suitable subset C of Banach spaces with the Opial's condition, locally uniform Opial condition, or uniform Opial condition.

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