• Journal of the Korean Geotechnical Society
• /
• v.37 no.4
• /
• pp.5-17
• /
• 2021

In this paper, three-dimensional analysis of the curved levee was performed according to curvature angle, and radius of curvature to investigate the property of seepage. The hydraulic gradients in the curved parts of levees decreased in the outer levee and increased in the inner levee, compared to the two-dimensional analysis. The smaller the curvature angle and the radius of curvature, the larger the change of the hydraulic gradient, compared to the two-dimensional analysis. The effect of curvature radius on the hydraulic gradient was greater than the curvature angle. As a result of evaluating the piping safety factor for the critical hydraulic gradient, the safety factor was increased by 2~5% in the outer levee and decreased by 4~12% in the inner levee, compared to the two-dimensional analysis. Considering this reduction, if the two-dimensional analysis is performed on the curved part of the levee, and if designed the safety factor for piping is 0.1~0.3 greater than allowable FS=2.0, the safety factor of the curved part is slightly reduced, but there is no difficulty in securing stability.

• Journal of Environmental Policy
• /
• v.5 no.4
• /
• pp.127-154
• /
• 2006

It has been widely accepted that the environment is an important determining factor of human health. Appreciating the relationship between the environment and human health, Korean government has begun to deal with issues of environmental health. The government proclaimed the year of 2006 to be the first year of Environmental Health and established "The Environmental Health Plan for the next 10 Year". In order to achieve the goals in the plan, there are necessary considerations such as support systems for environment health related research, investigation, law, institution, administration, and so forth. This study suggests basic principles required to establish a legal regime of environmental health which is to implement the environmental health policies in Korea. Several cases of foreign legislation and policy relevant to environmental health are reviewed. Also, existing related legal system in Korea are analysed considering legal and institutional elements for establishing an effective environmental health policy. The main purpose of amending legal system related environmental health is to protect both public health and the soundness of ecosystem. To reach the goals effectively, the concept of 'environmental health' should be clearly established and presented. In addition, an advanced prevention system, including investigation and prevention of the cause of environmental diseases and risk assessment based on the precautionary principle, are substantial in the environmental health legislation. Also the environmental health law should guarantee public participation in decision making as well as the first consideration of susceptible or vulnerable population. This study concludes that the expected legislation related to environmental health should be a nonnative instrument not only for integrating each environmental protection scheme but also for establishing and implementing the policy.

• The Journal of the Acoustical Society of Korea
• /
• v.40 no.3
• /
• pp.201-212
• /
• 2021

The present study was conducted as a pilot investigation to suggest the standards of acoustic performance for classrooms suitable for incomplete hearing people such as children under 9 years of age. Subjective evaluations such as questionnaire and speech intelligibility test were conducted to 264 students at two elementary schools in Cheong-ju in order to analyze the characteristics of the listening environment in the classrooms of the lower grades in elementary school. The survey was undertaken with a total of 264 students at two elementary schools in Cheong-ju, and investigated their satisfaction with the classroom listening environment. As a result, students responded that the most helpful information type for understanding class content is the voice of teacher. In addition, the volume of the current teacher's voice is normal, and the level of clarity is highly satisfactory. As for the acoustic performance of the classroom, the opinion that the noise was normal and the reverberation was very short was found to be dominant in overall satisfaction with the listening environment. Meanwhile, as a result of speech intelligibility test using the word list selected for the lower grade students of elementary school, it could be inferred that the longitudinal axis distance from the sound source in the case of 8-year-olds is a factor that affects speech recognition.

• The Journal of Sustainable Design and Educational Environment Research
• /
• v.12 no.2
• /
• pp.1-10
• /
• 2013

This study evaluates the relationship among the evaluation structure of morphological elements, the satisfaction on exterior elements, and the image evaluation for the campus landmarks by campus type. The investigation results are summarized as follows. 1) The university headquarter was nominated as the university landmark, and the main reason for the nomination was the building's historic and locational value. 2) Of the morphological elements of the campus landmark, 'proportion and balance' and 'harmony and order' were deemed important, while 'diversity' was deemed less important. 3) For the satisfaction on the facility's exterior elements, the evaluation structure was different for each university. However, the factor of 'location of the facility' was deemed the biggest factor for satisfaction for all universities, while the facility's 'color and material' were found to be the most dissatisfying factors. 4) The image evaluation on the facility was different for each university. Although there was a strong skeptical image about 'liveliness', there was a very positive image about 'elegance' and 'scale'. 5) On the relationship between the satisfaction on exterior elements and the image evaluation, there was a different evaluation structure for each university. 'Facility's color and exterior material' were the main elements which improved the overall image of the facility. Thus, the study results strongly suggest that an important task is to determine the maintenance direction through the emphasis on the relationship between exterior elements and image satisfaction for each university.

• Journal of Korean Society for Atmospheric Environment
• /
• v.19 no.E4
• /
• pp.177-186
• /
• 2003

The total of 1,454 aerosol samples were collected by high volume tape sampler at the Gosan Site in Jeju Island from 1992 to 1999, and the major water-soluble ionic components were chemically analyzed. The mean concentrations of nss-S $O_4$$^{2-}$, N $H_4$$^{＋}$, and N $O_3$$^{[-10]}$ showed high values, which were 6.73, 1.45, and 1.45 ${\mu}{\textrm}{m}$/㎥, respectively, while $Ca^{2+}$ and $K^{+}$ concentrations were low with the values of 0.49 and 0.42 $\mu\textrm{g}$/㎥. The concentrations of most components increased in spring but decreased in summer, especially with the remarkable increase of $Ca^{2+}$ and N $O_3$$^{[-10]}$ concentrations in spring. The seasonal comparison of nss-S $O_4$$^{2-}$ concentrations showed higher values with the order of spring > fall 〉 winter〉 summer, but spring 〉 winter〉 fall 〉 summer for N $O_3$$^{[-10]}$ Meanwhile, the concentration levels of N $a^{+}$ and C $l^{[-10]}$ increased more in winter season. According to the investigation of wind direction effect, the concentrations of most aerosol ionic components showed higher values consistently at the westerly and northerly wind conditions. Based on the factor analysis, the atmospheric aerosols in the Gosan Site are considered to be largely affected by marine sources, followed by anthropogenic and soil sources.urces..

• Journal of Ecology and Environment
• /
• v.32 no.2
• /
• pp.87-96
• /
• 2009

Pinus thunbergii plantations in Pohang-si, Gyeongsangbuk-do, Korea, are of low ecological quality, with arrested succession and a high proportion of ruderal species. To improve the quality of the habitat, we created canopy gaps ($\sim42\;m^2$) and monitored changes in abiotic (light availability, canopy openness) and biotic (survival and growth of seedlings and understory communities) variables in 2007 and 2008 in plots that had received one of five types of treatment: cutting of canopy trees and removal of the understory (CU), cutting of canopy trees only (C), girdling of canopy trees and removal of the understory (GU), girdling of canopy trees (G) or control. Each treatment was applied to three replicate plots. Abiotic variables did not significantly differ among treatments. Survival rates of target species were slightly lower in the CU, G and control conditions. Based on logistic regression analysis, the only significant growth factor affecting survival was height growth. Positive effects of seedling height and leaf area growth on survival were also detected, but did not reach statistical significance. In treatment G, gradual improvement of overstory conditions and mitigation of competition by limitation of disturbance to the understory community were likely to have promoted seedling growth. There were no significant effects of gap treatments on changes in species abundance (cover and richness) and composition of understory between the study years. This result implies that the small gaps created in our study may be below the threshold size to affect understory growth. However, the results of this study are based on a short-term investigation of only two years. Long-term research is strongly recommended to clarify the effects of gap treatment on plant communities in afforested areas.

• Journal of the Korea Safety Management & Science
• /
• v.15 no.1
• /
• pp.109-120
• /
• 2013

As information-oriented industry has been developed and electronic devices has come to be smaller, lighter, multifunctional, and high speed, the components used to the devices need to be much high density and should have find pattern due to high integration. Also, diverse reliability problems happen as user environment is getting harsher. For this reasons, establishing and securing products and components reliability comes to key factor in company's competitiveness. It makes accelerated test important to check product reliability in fast way. Out of fine pattern failure modes, failure of Electrochemical Migration(ECM) is kind of degradation of insulation resistance by electro-chemical reaction, which it comes to be accelerated by biased voltage in high temperature and high humidity environment. In this thesis, the accelerated life test for failure caused by ECM on fine pattern substrate, $20/20{\mu}m$ pattern width/space applied by Semi Additive Process, was performed, and through this test, the investigation of failure mechanism and the life-time prediction evaluation under actual user environment was implemented. The result of accelerated test has been compared and estimated with life distribution and life stress relatively by using Minitab software and its acceleration rate was also tested. Through estimated weibull distribution, B10 life has been estimated under 95% confidence level of failure data happened in each test conditions. And the life in actual usage environment has been predicted by using generalized Eyring model considering temperature and humidity by developing Arrhenius reaction rate theory, and acceleration factors by test conditions have been calculated.

• Journal of the Korean Society of Radiology
• /
• v.11 no.6
• /
• pp.517-523
• /
• 2017

As the research for evaluating the welfare satisfaction factor of radiological technologist who works in the clinic, this study was conducted to analysis the satisfaction factor, satisfaction level, and the improvements. During July 14, 2014 to March 31, 2015, after we sent out a total of 150 questionnaires for the survey to radiological technologists working at the clinic located in Gyoungsangnam province, 130 questionnaires suitable for research were analysis by using SPSS 18.0 statistical analysis software. As the welfare factors, working environment, financial support, educational opportunity, medical support, working culture, etc. were used. And as the sociodemographic characteristics, the gender, marriage, level of education, age, and working period were used. As a result of analysis of satisfaction level by welfare factors, working environment was $2.74{\pm}0.65$, financial support was $2.42{\pm}0.74$, educational opportunity was $2.24{\pm}0.72$, medical support was $2.68{\pm}0.69$, and working culture was $2.27{\pm}0.64$. Consequentially, the satisfaction level of welfare factor ($2.45{\pm}0.59$) was confirmed as below average. On the nature of the clinic, the management's lack of awareness of welfare is a realistic limit. In order to improve the satisfaction level of clinic's radiological technologist, it thought that there should be the proactive changes of the managements and the change of the medical staff 's perception. Moreover, it is important to provide selective welfare effectively by the investigation of employees' desire for welfare.

• 한국벤처창업학회:학술대회논문집
• /
• 2007.11a
• /
• pp.143-174
• /
• 2007

The objective of Starts-up education rears leading company that minimize a risk & connect them with successful idea. Internet Starts-up education is serviced in public & civil parts, it is insufficient to reach successful Starts-up support. This study is targeting on review the present condition of the Internet Starts-up education, research which it sees Internet Starts-up education actual condition investigation through investigation student of education satisfactorily and education contents and the plan to grope an Starts-up education progress coat problem and developmental plan it did. The current events point which has become research result escape first, age of the students of education, followed in educational background and, education motive and education experience presence education satisfactory boat song it appeared in these demand different, base grudge the form which is various it fixed and the education was demanded. Second, currently the department of pedagogy joining in establishment leader against the technical element which is advanced swip, the education reinforcement against an enterprise accomplishment ability back human factor, an enterprise propulsion environment and an enterprise item back enterprise environment element was demanded. Time after support and consulting, completion lifestyle community construction, completion lifestyle for item connection support and the trade name net after third, establishing an enterprise we the king, after toe ring back educating which carries on shoulder the importance of the civil official was embossed. The study which it sees led and like this investigation analysis the education progress for the successful support of the Internet Starts-up and time after connection setup construction it led and the plan which it will put out advancement of Starts-up education and it groped.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.3 no.1
• /
• pp.29-55
• /
• 2008

The objective of Starts-up education rears leading company that minimize a risk & connect them with successful idea. Internet Starts-up education is serviced in public & civil parts, it is insufficient to reach successful Starts-up support. This study is targeting on review the present condition of the Internet Starts-up education, research which it sees Internet Starts-up education actual condition investigation through investigation student of education satisfactorily and education contents and the plan to grope an Starts-up education progress coat problem and developmental plan it did. The current events point which has become research result escape first, age of the students of education, followed in educational background and, education motive and education experience presence education satisfactory boat song it appeared in these demand different, base grudge the form which is various it fixed and the education was demanded. Second, currently the department of pedagogy joining in establishment leader against the technical element which is advanced swip, the education reinforcement against an enterprise accomplishment ability back human factor, an enterprise propulsion environment and an enterprise item back enterprise environment element was demanded. Time after support and consulting, completion lifestyle community construction, completion lifestyle for item connection support and the trade name net after third, establishing an enterprise we the king, after toe ring back educating which carries on shoulder the importance of the civil official was embossed. The study which it sees led and like this investigation analysis the education progress for the successful support of the Internet Starts-up and time after connection setup construction it led and the plan which it will put out advancement of Starts-up education and it groped.