• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.4
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• pp.573-583
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• 2015

Objectives: This study was carried out to evaluate the effect of noise exposure and aging on changes in hearing threshold level and the relationship between age and noise. Materials: The author selected 274 male shipyard and assembly line workers as the noise exposed group and 582 males not exposed to noise as the general population group. Data were collected from five years of consecutive annual audiometric tests performed from 2008 to 2012. Results: In the general population and noise exposed groups, there was a reverse phenomenon that hearing threshold level for 2009 was lower than that of 2008, which seemed to be due to the learning effect, but from 2010 hearing threshold level increased. In the noise exposed group, the mean hearing threshold level in the left ear was significantly higher than that for right ear. In the general population group, the older was the age, the higher was the hearing threshold level, especially at 4000 Hz. In the general population and noise exposed groups, frequency, age group and noise exposure independently affected hearing threshold level, and there was no relationship between age and noise exposure. Over all frequencies, the change of hearing threshold level was larger in the noise exposed group than in the general population group. In the noise exposed group below thirty years old, the change at 4000 Hz was remarkable. Conclusions: Age and noise exposure seem to affect hearing threshold level independently and contribute to an additive effect on hearing threshold level.

• ALGAE
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• v.33 no.1
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• pp.21-35
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• 2018

The phototrophic dinoflagellate genus Scrippsiella is known to have a worldwide distribution. Here, we report for the first time, the occurrence of Scrippsiella lachrymosa in Korean waters. Unlike the other stains of S. lachrymosa whose cultures had been established from cysts in the sediments, the clonal culture of the Korean strain of S. lachrymosa was established from motile cells. When the sulcal plates of S. lachrymosa, which have not been fully described to date, were carefully examined using scanning electron microscopy, the Korean strain of S. lachrymosa clearly exhibited the anterior sulcal plate (s.a.), right sulcal plate (s.d.), left sulcal plate (s.s.), median sulcal plate (s.m.), and posterior sulcal plate (s.p.). When properly aligned, the large subunit (LSU) rDNA sequence of the Korean strain of S. lachrymosa was ca. 1% different from those of two Norwegian strains of S. lachrymosa, the only strains for which LSU sequences have been reported. The internal transcribed spacer (ITS) rDNA sequence of the Korean strain of S. lachrymosa was also ca. 1% different from those of the Scottish and Chinese strains and 3% different from those of the Canadian, German, Greek, and Portuguese strains. Thus, the Korean S. lachrymosa strain has unique LSU and ITS sequences. The abundances of S. lachrymosa in the waters of 28 stations, located in the East, West, and South Sea of Korea, were quantified in four seasons from January 2016 to October 2017, using quantitative real-time polymerase chain reaction method and newly designed specific primer-probe sets. Its abundances were >$0.1cells\;mL^{-1}$ at eight stations in January and March 2016 and March 2017, and its highest abundance in Korean waters was $26cells\;mL^{-1}$. Thus, S. lachrymosa has a nationwide distribution in Korean waters as motile cells.

• Journal of the Economic Geographical Society of Korea
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• v.9 no.3
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• pp.441-458
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• 2006

Culture is an indispensable element in modern society in improving the quality of life for city dwellers and stimulating the urbanization. The conspicuous emergence of cultural cities, which is a new paradigm, can be understood in that context. Global cities are pursuing cultural cities, and autonomous regions in Korea are also pushing ahead with the urbanization which combines cultural elements. Specifically, Nam-gu of Incheon has set an example of successful cultural city for other autonomous regions. The cultural environmental policy of Nam-gu is deemed to have retained the infrastructure, cultural urban landscape and living space, and a plenty of contents. The real significance of cultural city lies in the pursuit of sustainable urban development as a culture-friendly city. For that, the direction of cultural environmental city has to be firmly set, and related law and system should be strengthened. Above all, it is critical to pursue human-oriented cultural city by showing citizens what roles they have to play, setting the right direction, and improving the partnership.

• Journal of the Korean GEO-environmental Society
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• v.14 no.2
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• pp.13-17
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• 2013

Clogging phenomenon in drainage system is one of the important problems and this phenomenon would be bad effect to structure of tunnel, so it needs a remedy urgently. Recently, scale in drainage pipe is removed by water jet cleaning and other treatment. But these treatments need much cost and regular management. In this study, magnetic device was used to solve this problem and an effect of prohibiting scale in accordance with array of magnetic device was investigated. Analysis method was visual analysis and measuring weight of each pipes. As a result, interior top and out-bottom (CASE II) was the most effective array to prohibit scale. and interior left and right (CASE III), interior top and bottom (CASE I) was effective for prohibiting scale in order.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.744-753
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• 2017

The sediment delivery ratio (SDR) is widely used to estimate sediment loads by multiplying soil loss through the Revised Universal Equation (RUSLE). In this study, the SDR equation was developed for the Lake Imha watershed using soil loss calculated by RUSLE and sediment loads by the calibrated Hydrological Simulation. Program Fortran (HSPF). The ratio of watershed relief and channel length ($R_f/L_{ch}$), the ratio of watershed relief and watershed length ($R_f/L_b$), curve number (CN), area (A), and channel slope ($SLP_{ch}$) demonstrated strong correlations with SDR. SDR equations were developed by a combination of subwatershed parameters by referring to the correlation analysis. The area based power functional SDR developed in this study showed significant errors at the point right after entering major tributaries, because SDR was unrealistically reduced when the watershed area increased significantly. The $SLP_{ch}$-based power functional SDR also showed extraordinary values when the channel slope was gradual. The SDR equation that showed the highest value of the coefficient of determination also presented unrealistic changes in the sediment loads within a relatively short river distance. The SDR equation $SDR=0.0003A^{0.198}R_f/L{_w}^{1.167}$ was recommended for application to the Lake Imha watershed. Using this equation, sediment loads at the outlet of the Lake Imha watershed were calculated, and the HSPF parameters related to sediment in the uncalibrated subwatersheds were determined by referring to the sediment loads calculated with the SDR equation.

• The Journal of the Korea Contents Association
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• v.12 no.6
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• pp.230-237
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• 2012

Since the 1950s, crime prevention was to figure out how dissident. Unlike traditional crime prevention was a point of view. Physical environment and a method to prevent crime, "Crime Prevention Through Environmental Design (Crime Prevention Through Environmental Design: CPTED)" is the prevention of crime, property crime, criminals and human right with the surrounding environment. These CPTED has a variety of factors. Natural surveillance of these is the most basic elements. Natural surveillance is monitored by monitoring the behavior of criminals, to prevent crime. CPTED was the large majority of existing studies focused on a study area. However, this study examined the area around a house. Made to secure the hypothesis of natural surveillance to affect fear of crime. Research on fear of crime and crime victimization declined. Thus, the securing of natural surveillance proved to be effective in crime prevention in this study.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.608-617
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• 2020

For efficient use and expansion of domestic small- and medium-diameter woods, cross-laminated wood panels composed of tropical hardwoods and domestic temperate woods were fabricated, and the bending creep behavior under long-term loading was investigated. The bending creep curve of the cross-laminated wood panels showed an exponential function graph with a sharp increase at the top right side. The wood panel composed of a teak top layer and larch core and bottom layers recorded the highest initial deformation, and that composed of a merbau top layer and tulip core and bottom layers showed the lowest initial deformation. Creep deformation of the cross-laminated wood panels showed the highest value in that composed of a teak top layer and larch core and bottom layers and showed the lowest value in that composed of a merbau top layer and tulip core and bottom layers. The obtained creep deformation is 3.1-4.3 times that of merbau, however, it is remarkably lower than that of tulip and larch. The highest relative creep was recorded by the wood panel composed of merbau top layer and larch core and bottom layers, whereas that composed of the teak top layer and tulip core and bottom layers showed the lowest relative creep.

• Journal of Environmental Impact Assessment
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• v.28 no.4
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• pp.400-412
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• 2019

The process of assessing environmental values and impacts is subjective and depends on predictions, limiting the securing of scientific rationality. Therefore, it is necessary to make a supplement by securing procedural rationality. This study has been tried to secure procedural rationality of EIA based on information disclosure system. The Aarhus Convention is an international treaty that defines the right of the public to access to environmental information and to participate in decision-making. This study evaluates Korean EIA information disclosure system by deriving 10 indicators based on the provisions on information disclosure presented in the Aarhus Convention. As a result, the five indicators were satisfied in terms of direction of information disclosure and provision. And the four indicators for the basis of utilization and process are required to be supplemented by detailed regulations. Finally, we derive the need for research on the asymmetry of expertise and acceptability of EIA system through public understanding indicators.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.24 no.3
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• pp.85-98
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• 2021

In this study, the characteristics of tree growth and soil environment were analyzed at 5 sites that had been planted on the back slope of dam for more than 15 years in Korea. First, as a result of investigating the growth of 15 trees planted on the back slope of the dam, the average height was 10.6m, diameter at roots was 27.3cm, and DBH was 22.9cm, showing good growth status of most of the trees. In particular, the growth levels of pine, hackberry, and oak were similar or better than those of general forests and artificial ground. As a result of excavating and investigating the roots of trees, horizontal roots grew well in the left and right directions of the back slope of the dam, and the growth of vertical roots was insufficient. Currently, the roots of trees do not directly affect dam safety, but they may continue to grow in the long term and interfere with dam management. Second, the physicochemical characteristics of the soil on the back slope of dam were generally above the intermediate level in terms of landscape design standards, and were similar to those of the domestic forest soil. Therefore, although it was judged to be suitable for plant growth, isolation of the site, soil acidification, and nutrient imbalance may affect tree growth and forest health in the long term. Through this study, it was possible to confirm the potential and applicability of planting area on the back slope of dam as an ecological base. Continuous monitoring is required for safety management and ecological value of dams in the future, and through this, it will be possible to secure the feasibility of planting trees on the slopes of new or existing dams and improving management.

• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.311-321
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• 2021

Perception of the public to structural fires is very important because there are only a number of tall timber buildings constructed in the world. People are hesitating to accept tall timber buildings, so it is essential to ensure the first generation of tall timber buildings to a very high standard, especially fire safety. Right now, there are no specific design standards or regulations for fire design of tall timber buildings in Europe. Even though heavy timber members have better fire resistance than steel components, many conditions still need to be verified before considering the use of timber materials, e.g. fire spread, post-fire collapse, etc. This research numerically explores the structural behaviours of a tall Glulam building when one of its internal Glulam (Glued laminated timber) columns fails after sustaining a full 120-min standard fire and is removed from the established finite element building model created in SAP2000. The numerical results demonstrate that the failure and removal of the selected internal Glulam column may lead to the local failure of the adjacent CLT (Cross laminated timber) floor slabs, but will not lead to large disproportionate damage and collapse of the whole building. Here, the building is assumed to be located in Glasgow, Scotland, UK.