• Title/Summary/Keyword: sun-exposure

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Sun Protection Use Behaviour among University Students from 25 Low, Middle Income and Emerging Economy Countries

  • Pengpid, Supa;Peltzer, Karl
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1385-1389
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    • 2015
  • The aim of this study was to investigate the sun protection use behaviour among university students from 25 low, middle income and emerging economy countries. Using anonymous questionnaires, data were collected from 18,687 undergraduate university students aged 18-30 years (mean age 20.8, SD=2.8) from 26 universities in 25 countries across Asia, Africa and the Americas. Overall, 57.2% of university students reported liking to sunbathe and of those only 48.1% used sun protection when sunbathing. In multivariate logistic regression, younger age, being female, coming from a wealthy or quite well off economic family background, living in an upper middle or high income country, lighter skin tone, and other health behaviours were found to be associated with sun protection use behaviour. Low sun protection use calls for health promotion programmes to prevent unprotected sun exposure.

Effects of harsh environmental exposures on the bond capacity between concrete and GFRP reinforcing bars

  • Al-Tamimia, Adil;Abed, Farid H.;Al-Rahmani, Abdulla
    • Advances in concrete construction
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    • v.2 no.1
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    • pp.1-11
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    • 2014
  • This paper demonstrates an experimental study to evaluate the effects of environmental exposures on the bond between ribbed Glass Fiber Reinforced Polymer (GFRP) reinforcing bars and concrete. The equation recommended by ACI 440-1R-06, for the bond stress,was evaluated in this study. A total of 16 pullout samples, 12with GFRP bars and 4with steel bars, were exposed to two different harsh environments for different periods of time. The exposed harsh environments included direct sun exposure and cyclic splash zone sea water. The variation in the shear (bond) strengths before and after exposure was considered as a measure of the durability of the bond between GFRP bars and concrete.Experimental results showed there is no significant difference of the bond strength between 60 and 90 days of exposures.It also showed that the empirical equation of the bond stress calculated by ACI 440-IR-06 is very conservative.

A Survey on Patient Dose and Exposure Conditions in Simple Radiography of the Abdomen (복부 단순 X-선 촬영조건과 환자 피폭에 관한 조사 연구)

  • Kim, Sung-Soo;Lee, Sun-Sook;Huh, Joon
    • Journal of radiological science and technology
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    • v.19 no.2
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    • pp.59-65
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    • 1996
  • We studied exposure techniques and exposure dose for simple abdomen A-P projection for 41 medical facilities that are located in Seoul area. 1. The range of tube voltage used was 60 to 84 kVp, the average tube voltage used was 74 kVp 2. Only 17% of added filter was used. 3. Tube current mostly used was 200 mA, some of them used 400 mA. 4. The grid ratio mostly was used 10 : 1, 54 % of the rare earth screen was used in most facilities. 5. The average skin entrance dose was 4.15 mSv and the dose range was 1.05 mSv to 11.0 mSv.

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A Experimental Study on the Correction Methods of X-ray Exposure Factors (촬영조건의 교정에 관한 실험)

  • Huh, Joon;Kim, Chang-Kyun;Lee, Sun-Sook;Kim, Hak-Seong
    • Journal of radiological science and technology
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    • v.7 no.1
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    • pp.67-70
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    • 1984
  • Radiographic units have changeable factors in x-ray outputs, Therefore, an exposure factor by basic experimental study must be made out about each x-ray installation, but this is very intricate methods and not a practical business. Authors tried out a new method to make simple exposure factors. The first, we had a experimental object radiograph taken to find the output of each radiographic unit. The second, by obtained x-ray density we found the difference in x-ray output. and lastly, we made a new and simple correction method to use the obtained output and x-ray density.

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Application of Physiologically Based Pharmacokinetic Modeling with Biological Monitoring Data for Risk Assessment (생물학적 모니터링 데이터를 기초한 PBPK 모델의 활용)

  • Yang, Mi-Hi;Yang, Ji-Yeon;Yi, Bit-Na;Lee, Ho-Sun
    • Environmental Analysis Health and Toxicology
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    • v.22 no.1 s.56
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    • pp.1-8
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    • 2007
  • Biological monitoring, analyses of internal dose for exposure to toxicants, has been thought as one of the belt approaches for risk assessment. As the amount detected in human samples is generally very low, typically in the parts-per-bilion (ppb) or parts-per-trillion (ppt) range, analytic technologies such at HPLC, GC/MS, LC/MS, and LC/MS/MS have been continuously developed. In addition, route specific and sensitive exposure biomarkers have been developed for proper biological monitoring. PBPK modeling, particularly reverse dosimetry, has been emphasized as an useful method via interpretation of biological monitoring results for regulation of toxicants. Thus, this review is focused on the use of PBPK dosimetry models for toxicology research and risk assessment in Korea.

PARTIAL KEY EXPOSURE ATTACKS ON RSA AND ITS VARIANT BY GUESSING A FEW BITS OF ONE OF THE PRIME FACTORS

  • Sarkar, Santanu;Maitra, Subhamoy
    • Bulletin of the Korean Mathematical Society
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    • v.46 no.4
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    • pp.721-741
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    • 2009
  • Consider RSA with N = pq, q < p < 2q, public encryption exponent e and private decryption exponent d. We first study cryptanalysis of RSA when certain amount of the Most Significant Bits (MSBs) or Least Significant Bits (LSBs) of d is known. The basic lattice based technique is similar to that of Ernst et al. in Eurocrypt 2005. However, our idea of guessing a few MSBs of the secret prime p substantially reduces the requirement of MSBs or LSBs of d for the key exposure attack. Further, we consider the RSA variant proposed by Sun and Yang in PKC 2005 and show that the partial key exposure attack works significantly on this variant.

A Design of Improved Auto Exposure System for Digital Still Camera (개선된 디지털 카메라용 자동노출 시스템의 구현)

  • Lee, Sang-Yang;Cho, Sun-Ho;Park, Chong-Kug
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.110-112
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    • 2005
  • In this paper, an improved AE (auto exposure) system for digital still camera is proposed. The AE system is the most important part in camera to get high quality picture image. However, there is no remarkable progress in this field until this time in spite of its importance. In recent, some researchers try to develop an AE system with signal processing technique. But it has some problems in exposure time and sometimes generates oscillation in brightness. Therefore, we develop a new system using a control technology to remove such phenomena. This new system shows about 30% improved performance than conventional one.

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Comparison of Radiosensitivity of Bacteria Isolated from Given Radiation Exposure History (방사선 피폭역을 달리하여 분리한 세균의 방사선감수성 비교)

  • Kim, Gi Su;Min, Bong Hui;Lee, Gang Sun
    • Korean Journal of Microbiology
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    • v.12 no.2
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    • pp.69-69
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    • 1974
  • This experiment was carried out to identify and to compare the radiosensitivities of bacteriz isolated from the sources of different radiation exposure histories. Among 10 strains isolated in this investigation, 4 strains of bacteria, Bacillus firmus, Bacillus brevis, Baciilus subtilis and Bacillus sphaericus were isolated from high and low radioactive sites simulaneously. Bacterial strains isolated from radioactive sources such as reactor and isotope production rooms were more resistant to irradiation than the microganisms from medical products and laboratories, however, there was no significance in radiosensitivity in the same species of bacteriz, even if they were isolated from different radiation exposure histories.

XPS Studies of Oxygen Adsorption on Polycrystalline Nickel Surface

  • Lee, Soon-Bo;Boo, Jin-Hyo;Ahn, Woon-Sun
    • Bulletin of the Korean Chemical Society
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    • v.8 no.5
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    • pp.358-362
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    • 1987
  • The interaction of oxygen with polycrystalline nickel surface has been studied by investigating the X-ray photoelectron spectra of O 1s, Ni $2p_{3/2}$, and their valence band electrons. By comparing the oxygen exposure of this work with the reported results of LEED, AES, and work function measurements, it is found that the atomic oxygen, adsorbed dissociatively in the initial stage of exposure, is responsible for a p(2 ${\times}$ 2) structure and a subsequent c(2 ${\times}$ 2) structure on the Ni(100) surface. This dissociatively adsorbed oxygen species forms surface NiO layer subsequently on further oxygen exposure. The NiO layer is more easily formed with the increasing temperature. Non-stoichiometric oxygen species is also found to accompany the NiO layer. It appears prior to the formation of bulk NiO at all of the temperatures of this work except at 523K.

Effect of the Properties of Sound Source and Transmission for the Evaluation of Subjective Response by the Exposure Time of Transportation Noise (교통소음의 노출시간에 따른 주관반응 평가시 음원 및 전달 특성의 효과 분석)

  • Kim, Sun-Woo;Kim, Won-Sik;Song, Guk-Gon;Kang, Jong-Ku;Park, Hyeon-Ku
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.3
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    • pp.264-274
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    • 2012
  • Evaluation on the environmental noise is carried out by surveying subjective response of residents with physical measurement of noise during long period in field. Particularly field survey is used to make regulations from the analysis on how many people are annoyed for specific noise level, and laboratory test used to analyze the relationship between physical parameters of noise and subjective responses. In the laboratory controlling the variables is easy but the results could be biased because the condition in room would be different with field. Most of all noise exposure time is considered to be different with real situation, and this study aimed to evaluate the subjective response by exposure time of transportation noise, by applying three kinds of variable how much they give effects on the annoyance as the exposure time is operating condition, windows type and sound level. As a result there was somewhat difference between operating type and annoyance, which is caused by the sound characteristics operated in different condition. However the window type didn't give much effect to the annoyance as much as sound type. This means that the subjective response could give similar result by exposure time even for different window types. Most of all, the main factor affecting subjective response is considered to be the sound level and the exposure time.