• Title/Summary/Keyword: Sound Exposure Level

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Analyzing the Relationship between the Spatial Configuration of Urban Streets and Air Quality (도시가로의 형태요소와 대기질과의 관계 연구)

  • Chu, Junghyun;Oh, Kyushik;Jeong, Yeun-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.12 no.2
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    • pp.73-82
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    • 2009
  • The traffic volume of Seoul is extremely high in comparison to other major cities in Korea, and the result has been harmful physical and mental exposure to pollution by Seoulites on a regular basis. The street air pollution is more important than the others, because the air pollution generated by street traffic directly impacts the health of nearby pedestrians. This problem requires urgent attention and resolution. Among the factors creating the air pollution originating from the street, is the configuration of streets, which have emerged as the most significant because it is related to air and pollutant dispersion. Therefore, this study was conducted under the assumption that street form affects the air quality. Study sites were classified by street characteristics, and air quality was analyzed in each class. Then the OSPM (Operational Street Pollution Model) was employed to simulate the relationship between street configuration and air quality of streets within the old city center and new city center in Seoul. After that this study analyzed the correlation between air pollution and the spatial configuration of urban streets (ex. street width, building height, building density, etc.) to determine their contributions to air pollution. The outcome of this study is as follows : First, the result that was derived from the correlation analysis between street configuration and air quality hewed that the air pollution of the street is influenced by the average height of building, width of the roads as well as traffic volume. On the roadside, the concentration level of $NO_2$ is mainly affected by the average height of building and the deviation of building height along the street and CO is affected by street width. The outcome of this study can be used as a basis for more sound urban design policies, and the promotion of desirable street environments for pedestrians.

A Survey on the Status of Noisy Working Environment in Manufacturing Industries (제조업 산업장의 소음 작업환경 실태에 관한 조사 연구)

  • Kim, Joon-Youn;Kim, Byung-Soo;Lee, Chae-Un;Jun, Jin-Ho;Lee, Jong-Tae;Kim, Jin-Ok
    • Journal of Preventive Medicine and Public Health
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    • v.19 no.1 s.19
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    • pp.16-30
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    • 1986
  • In order to prepare the fundamental data for the improvement of noisy working environments and the effective hearing conservation program on workers exposed to industrial noise, the authors surveyed the working processes and evaluated the noise levels on 56 manufacturing industries in Pusan area from April to July in 1985. The results were summarized as follows : 1. The noise level was the highest in shipbuilding and repairing(95.6 dBA), and followed by steel rolling(94.0 dBA), manufacture of motor vehicles(93.1 dBA), manufacture of fishing nets(92.9 dBA), manufacture of testiles(92.5 dBA), iron and steel foundries(89.3 dBA), manufacture of metal products(89.1 dBA), preserving and processing of marine foods(87.0 dBA), manufacture of rubber products(85.3 dBA), manufacture of plywood(84.9 dBA) and manufacture of paints(84.5 dBA). 2. Among fifty surveyed working processes, the noise level of twenty-one processes (42%) exceeded the threshold limit value for 8 hours per day. 3. As the allowable exposure times by governmental threshold limit values to industrial noise level(dBA), cocking of shipbuilding and repairing and plating(CGL) of steel rolling were the shortest(30 minutes), and followed by assembling(rivet) of manufacture of motor vehicles(1 hour) weaving of manufacture of textiles and shot, machine, pipe laying of shipbuilding and repairing(2 hours). 4. By the result of octave band analysis on noisy working processes in excess of 90 dBA, the sound level was the highest at 2,000 Hz or 4,000 Hz. 5. It was recognized that the measurement of overall sound pressure level was also effective as octave band analysis in evaluating the industrial noise.

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Relationship between Access to Lewd Internet Contents by Middle School Students and Their Awareness of Sex (중학생의 인터넷음란물 접속과 성 의식의 관계)

  • Lim, Jong-In;Choi, In-Sook
    • The Journal of Korean Society for School & Community Health Education
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    • v.4
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    • pp.117-139
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    • 2003
  • The purpose of this research lies in presenting logical viability for the measures that curtail access to lewd Internet contents by middle school students amidst the reality in which lewd contents are circulated freely through the Internet, a medium that the middle school students find most easy to access. In order to establish right form of awareness towards sex, this research identified the ways they access the lewd Internet contents, their reaction after the exposure to those contents, their knowledge of sex, their concerns regarding sex and their accessibility to sexual activities in order to conduct a comparative analysis on the relationship between lewd Internet contents and their awareness of sex. First, realities of accessing lewd Internet contents and reactions according to the demographics of middle school students There isa significant difference in the experience of accessing lewd Internet contents in terms of gender. Mostly, male students tend to access the contents more. As for the way they access the lewd Internet contents, both male and female students replied that they access through spam mail of lewd nature. Thus, measures to address this problem are needed urgently. As to when they first accessed the lewd contents, most of the research subjects replied that they accessed either in elementary school period or in the early middle school period. This shows that most of the students got exposed to lewd contents even before they could establish positive, correct awareness of sex. Thus, there is a risk that they may formulate wrong kind of sexual awareness. Accordingly, it is necessary to develop measures through focused sex education. Students are divided into two groups according to the time they spend on the contents averagely: those who spend over one hour and those who spend less than an hour on the lewd contents. If the students spending longer hours are not to be checked and properly guided, it may lead to increasing cases of sexual delinquencies due to their wrongly formed awareness of sex. When the question of existence(non-existence) of guardian was addressed, students with both parents tend to access the lewd Internet contents in a more diverse manner and tend to access more compared to those students from single parent or no-parent families. Accordingly, guardians need to pay attention to how their children are using the Internet. Second, awareness of sex depending on the middle school students' demographics In case of sexual knowledge, middle school students shows relatively high level of knowledge. In particular, female students are found more knowledgeable than male students, and the students in upper years are more knowledgeable as well. As a result, this research recommends that the students in lower years should be guided with more basc and detailed information, while those in upper years need to be taught to form and express their own thoughts and attitudes and to build up independence on this matter. In case of worries about sex, both male and female students don't worry too much about it. However, male students are more concerned about sex than female students in a more diverse ways. As for the differences by academic year, concerns for sex increase, as students get older. Accordingly, sex education that helps establish sound perception of the opposite sex and that focuses on the etiquettes that one must adhere to at the presence of the opposite sex need to be conducted against middle school students. In case of accessibility to sex, male students manifest higher tendency than female students. As for the differences by academic year, those in the first and second years show higher accessibility than those in their third year. In general, younger students tend to be more open-minded toward sex. Accordingly, students in lower academic years need to undergo basic knowledge oriented sex education, whereas those in upper academic years need to undergo discussion centered sex education where they subject to questions regarding their attitude and opinion. Third, relationship between the reactions after the exposure to the lewd Internet contents and their awareness of sex As the frequency of contact with lewd Internet contents increases, awareness of sex increases as well. Thus, the lewd Internet contents contribute to the increase in students' concern for sex as well as increase in accessibility to sex, which eventually become barriers to students' establishment of a healthy perception of sex. Reactions to sex after the exposure to lewd Internet contents and awareness of sex indicate a significant correlation. However, negative correlation is manifested with knowledge of sex. Thus, it is possible to know that the greater access to lewd Internet contents does not necessarily translate into increase in knowledge of sex. However, the study showed there is a correlation between concerns for sex and the level of accessibility to sex. In more detail, the more reactions to the contents they show, the more concerns for sex they have and the more positively they take acceptability to sex. Moreover, it is necessary to develop necessary measures since textbooks today do not include measures needed to address the lewd Internet contents. Given the above findings, it is necessary to continue to complement structural measures in order to prevent easy access of lewd Internet contents by middle school students. Moreover, it is necessary to be considerate of the students so that they themselves can form a healthy Internet culture and grow up within positive framework for the sex education.

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Multi-objective Genetic Algorism Model for Determining an Optimal Capital Structure of Privately-Financed Infrastructure Projects (민간투자사업의 최적 자본구조 결정을 위한 다목적 유전자 알고리즘 모델에 관한 연구)

  • Yun, Sungmin;Han, Seung Heon;Kim, Du Yon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1D
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    • pp.107-117
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    • 2008
  • Private financing is playing an increasing role in public infrastructure construction projects worldwide. However, private investors/operators are exposed to the financial risk of low profitability due to the inaccurate estimation of facility demand, operation income, maintenance costs, etc. From the operator's perspective, a sound and thorough financial feasibility study is required to establish the appropriate capital structure of a project. Operators tend to reduce the equity amount to minimize the level of risk exposure, while creditors persist to raise it, in an attempt to secure a sufficient level of financial involvement from the operators. Therefore, it is important for creditors and operators to reach an agreement for a balanced capital structure that synthetically considers both profitability and repayment capacity. This paper presents an optimal capital structure model for successful private infrastructure investment. This model finds the optimized point where the profitability is balanced with the repayment capacity, with the use of the concept of utility function and multi-objective GA (Generic Algorithm)-based optimization. A case study is presented to show the validity of the model and its verification. The research conclusions provide a proper capital structure for privately-financed infrastructure projects through a proposed multi-objective model.

Comparative Analysis of Particulate Matter, Black Carbon, and Noise Levels Before and After Installation of a Safety Wall in a Pedestrian Walkway within an Urban Tunnel (도심터널 보행로 안전벽 설치 전후의 미세먼지, 블랙카본, 소음 수준 비교)

  • Myoungho Lee;Jongmin Park;Sohyun Kang;Jeongyeon Park;Taehong Kwon;Chungsik Yoon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.34 no.3
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    • pp.214-221
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    • 2024
  • Objectives: People using pedestrian walkways within tunnels may be exposed to environmental hazards that can have adverse effects on their health. This study aimed to measure changes in the levels of particulate matter (PM10), black carbon (BC), and noise after the installation of safety walls on pedestrian walkways within tunnels. Methods: Measurements were taken at the entrances on both sides of a tunnel and at the central point, both before and after the installation of pedestrian safety walls. Additionally, measurements were conducted by distinguishing between non-rush hour and rush hour periods to account for variations in the number of vehicles using the tunnel. A SidePak was used for PM10 measurements, an aethalometer for BC, and a sound level meter for noise. Results: PM10 showed the highest concentrations at the center of the tunnel at both pre- and post-installation of safety walls, as well as during rush hour periods. After the installation, the concentration at the center was 31.09 ± 14.02 ㎍/m3 (19.44 ± 8.02% increase). During rush hour, BC concentration reached 2.28 ± 1.55 ㎍/m3, indicating a 26.71 ± 13.19% increase compared to non-rush hour. As for noise, installation of safety walls reduced noise levels about 3 - 6 dB (8.10 ± 3.31% decrease). Conclusions: It was confirmed that installing safety walls on pedestrian walkways within the tunnel can reduce noise levels. However, the interior of a tunnel is a poorly ventilated environment, and exposure levels vary depending on the length of the tunnel. Therefore, the development of safety measures related to this issue is warranted, and further research on harmful substances within the tunnel should be conducted.