• Title, Summary, Keyword: Protection Factor

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Risk and Protection Factor Related to Suicide Ideation in Each Life Course based on an Ecological-system Perspective (생태체계적 관점에서 본 생애주기별 자살생각의 위험요인과 보호요인)

  • Kim, Yun-Jeong
    • The Korean Journal of Community Living Science
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    • v.22 no.3
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    • pp.429-444
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    • 2011
  • The objective of this study was to identify the risk factor and protection factor related to suicide ideation in each life course based on an ecological-system perspective. A questionnaire was carried out for 393 adolescents, 473 adults and 376 aged men living nationwide. The results are as follows. First, the suicide ideation was low with 1.78 points in the full mark of 5 points. Second, the difference in suicide ideation, depression, hopelessness, stress in the organic system variables, family solidarity in the micro system variables, intermediate system variables, residence, the existence/inexistence of counselling center and the influence of mass media in mezo system variables in each life course were significant. Third, the relative influence of organic system variables on the suicide ideation were largest in all life courses. Further, the depression and the influence of mass media in all life courses were a risk factor of suicide ideation and stress was also a risk factor of suicide ideation in the case of adolescents and the aged. When examining protection factors of suicide ideation, family solidarity, minute as it is, works as the protection factor of suicide ideation in the case of adolescents. For the adults, living in a metropolis was a protection factor from suicide ideation. For the aged, family solidarity, family history of suicide and adult children's attention to their friends and neighbors (intermediate system variable) were protection factors from suicide ideation. I suggested that policy, service, counseling and educational program proper to each life course were necessary to lower risk factors of suicide ideation and to improve protection factors.

A Study on the Determination of Required Fire Protection Thickness Considering Steel Section Shape (강재단면형상을 고려한 소요 내화피복 두께 산정에 관한 연구)

  • Kim, Hae-Soo;Kang, Jong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5910-5916
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    • 2011
  • Surface area of the steel member exposed to fire differs according to type and size of the section and the kind of the member, which shows a big difference in the temperature rise of the steel by fire. The section factor ($H_p$/A) is determined by factors such as type, size, and member of the steel and type of the fire protection material, and it is the criteria in determining thickness of the fire protection material. This study showed that the size of the steel increase regardless of the steel type, the section factor decrease. In the results on fire protection thickness of the steel according to the section factor, the efficiency of 1 hour fire protection was lower from 30 to 50% than the criteria. And there is the member, which have the thickness lower the minimum 27% in 2 hour fire protection, but it generally approached in the criteria. In case of H-shape steel, the efficiency of 3 hour fire protection was suitable for the criteria, but rectangular hollow steel section and circular hollow steel section were higher (5.0-17.5%) than the criteria.

Evaluation of a New Workplace Protection Factor―Measuring Method for Filtering Facepiece Respirator

  • Sun, Chenchen;Thelen, Christoph;Sanz, Iris Sancho;Wittmann, Andreas
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.61-70
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    • 2020
  • Background: This study aims to assess whether the TSI PortaCount (Model 8020) is a measuring instrument comparable with the flame photometer. This would provide an indication for the suitability of the PortaCount for determining the workplace protection factor for particulate filtering facepiece respirators. Methods: The PortaCount (with and without the N95-CompanionTM) was compared with a stationary flame photometer from Moores (Wallisdown) Ltd (Type 1100), which is a measuring instrument used in the procedure for determining the total inward leakage of the particulate filtering facepiece respirator in the European Standard. Penetration levels of sodium chloride aerosol through sample respirators of two brands (A and B) were determined by the two measuring systems under laboratory conditions. For each brand, thirty-six measurements were conducted. The samples were split into groups according to their protection level, conditioning before testing, and aerosol concentration. The relationship between the gauged data from two measuring systems was determined. In addition, the particle size distribution inside the respirator and outside the respirator was documented. Linear regression analysis was used to calculate the association between the PortaCount (with and without the N95-CompanionTM) and the flame photometer. Results: A linear relationship was found between the raw data scaled with the PortaCount (without N95-CompanionTM) and the data detected by the flame photometer (R2 = 0.9704) under all test conditions. The distribution of particle size was found to be the same inside and outside the respirator in almost all cases. Conclusion: Based on the obtained data, the PortaCount may be applicable for the determination of workplace protection factor.

A Case Study of the Commom Cause Failure Analysis of Digital Reactor Protection System (디지털 원자로 보호시스템의 공통원인고장 분석에 관한 사례연구)

  • Kong, Myung-Bock;Lee, Sang-Yong
    • IE interfaces
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    • v.25 no.4
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    • pp.382-392
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    • 2012
  • Reactor protection system to keep nuclear safety and operational economy of plants requires high reliability. Such a high reliability of the system can be achieved through the redundant design of components. However, common cause failures of components reduce the benefits of redundant design. Thus, the common cause failure analysis, to accurately calculate the reliability of the reactor protection system, is carried out using alpha-factor model. Analysis results to 24 operating months are that 1) the system reliability satisfies the reliability goal of EPRI-URD and 2) the common cause failure contributes 90% of the system unreliability. The uncertainty analysis using alpha factor parameters of 0.05 and 0.95 quantile values shows significantly large difference in the system unreliability.

A Study on Symbolism of Man's Neckwear (남성용 네트웨어에 나타난 상징성)

  • 유태순
    • Journal of the Korean Society of Costume
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    • v.31
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    • pp.203-214
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    • 1997
  • The neck is the human body is closely con-nected with the life and properties of keeping warm as one of the opening part in clothes. In ancient times it was put on necklace for the protection of neck and in Rome it was worn muffler called focale for the protection of neck throat. in addition cravat directly originated in necktie today was primarily worn for the protection of soldier's neck and has been turned into decorative purpose until today. As the ornament is developed to vari-ous kinds of form the neck decoration is changed and grown again and again. Therefore this thesis studies history of the neckwear and various the symbolic factor. The first factor is the social. The neckwear shows the social position class and status and does social mutual interaction as conversation starters. The second factor is the mental It express individuality fondness attitude and is felt to be indignity by being forced to be worn. The third factor is the political. it shows political tendency by indicating the royal sign or part's sign in necktie like the French royal-ist's green muffler The forth factor is the man's sexual. I expresses wearing stock being brave symbol-izing independence. The sixth factor is the traditional. It is worn with appearing traditionand custom and one of cultural movements. The seventh factor is the ideological. It symbolizes the freedom of suffragettes and emancipation of woman. The social factor is the most extensive among them. The neckwear is various in the way of expression like its kinds and is generalized, It functions as a independent part of clothes.

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The effect of vegetation parameter characteristics of the multi-layer vegetation model on wind for numerical simulation of micro-meteorology (미기상 수치모의를 위한 다층식생모델의 식생 팍라메타가 바람에 미치는 영향)

  • 오은주;이화운;정용현
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.605-613
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    • 2003
  • In order to make use of the protection effect against wind by the vegetation, it examined whether it should make what vegetation form and arrangement using the 2-dimensional non-hydrostatic model. When the foliage shielding factor increases, it becomes hard to take in protection effect against wind in a residential section. When it makes height of vegetation high, it becomes hard to take in protection effect against wind with height. In the comparison in the case where vegetation high is gradually made low toward wind-stream from a vegetation, and the case of making it low gradually, although former tends to receive the protection effect against wind by the vegetation, attenuation of wind velicity becomes large. In the comparison in the case where foliage shielding factor and distribution of density of leaf are gathered gradually toward wind-stream from a vegetation. It has been understood to evaluate to height the influence that the vegetation multi-layer model by which the heat revenue and expenditure in the direction of the vegetation height is considered is used, and to characterize the vegetation group by the parameter setting.

Study on the Determination of Fire Protection Thickness based on Section Factor (강재의 단면형상에 따른 내화피복두께 산정 연구)

  • 정청운;지남용;권인규
    • Proceedings of the Korean Institute of Building Construction Conference
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    • pp.139-142
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    • 2003
  • Traditionally, the thickness of fire protection materials of structural elements such as beam and column have been decided by fire test using the predominant steel section of $H-300{\times}300{\times}10{\times}15$ for column and $H-400{\times}200{\times}8{\times}13$ for beam in Korea. But this way of determination of fire protection thickness yields very unduly results. Because the temperature-increment rate of structural steel elements depends mainly on magnitude of their cross-areas. In general, the thicker size of cross-areas for structural elements, the lower temperature shows up. It had already proved that the fire protection thickness only depends on the size of cross-areas and the fire protection method for three-fide or four-side exposed conditions in European countries, the United State of America and so on. To demonstrate there would be differences among various cross-areas for structural elements, we conducted several fire tests with full-scale specimens of beams and columns. For the determination of critical temperature for steel section when the fire resistant performance is needed to be decided, we conducted with a loaded fire test for beam and column, respectively. The small column in 1.0 meter length and beam in 1.5 meter length were used in order to deprive the rational fire protection thickness of structural elements such as beam and column, respectively. After test, we could obtain there were significant temperature lass between higher cross-areas and lower cross-areas. The critical temperature of steel as a criterion is used 538$^{\circ}C$ for column and 593$^{\circ}C$ for beam which is from ASTM E 119 because we don't make provisions as critical temperature by elements. We could consider that the best way of determination of fire protection thickness is using the following multi-regression equation which was deprived from several fire tests using the concept of section factor, FR(column) = 0.17 +5191.49t A/Hp + 40.77t, FR(beam) = 0.25 +6899.31t A/Hp + 32.60t(where, FR means fire resistant time, t means thickness, A means cross-area and Hp means heated parameter).

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Considering on the Ground Reflection Effect on the Electromagnetic Fields due to Lightning Channel

  • Izadi, Mahdi;Ab Kadir, Mohd Zainal Abidin;Hajikhani, Maryam
    • Journal of Electrical Engineering and Technology
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    • v.8 no.4
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    • pp.824-831
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    • 2013
  • Lightning electromagnetic fields are important issues for the evaluation of lightning induced overvoltage on power lines and for setting the appropriate protection level for power networks. Such electromagnetic fields are strongly dependent on lightning return stroke currents at different heights along the lightning channel. On the other hand, the ground reflection factor due to the difference between the return stroke channel impedance and the equivalent ground impedance at channel base can have an effect on the shape of the return stroke currents by entering additional reflected currents into the channel. In this paper, the effect of the ground reflection factor on the return stroke currents at different heights along a channel and the electromagnetic fields associated with the lightning channel at close distances are considered. Moreover, the behavior of the electromagnetic fields versus the reflection factor changes and the radial distance changes are considered and the results are discussed accordingly. The results illustrate that the reflection factor has a direct relationship with the values of the electromagnetic fields while this is usually ignored in earlier studies.