• Asian Journal of Turfgrass Science
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• v.9 no.4
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• pp.285-292
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• 1995

To elucidate the mineral cycles of potassium in a dynamic grassland ecosystem in a steady state condition, this investigation was cunducted along the northwest side on Mt. Kwanak. The exper-imental results may he summarized on communities of Z. japonica and M. sinensis as follows. As compared with some pronerties of the surface soils among two semi-natural grasslands, the levels of exchangeahle potassium were high in M. sinensis and low in Z. japonica. Contents of potassium for the litters of Z. japonica and M. sinensis were 1.69% and 2.51%, re-spectively. The annual production of potassium was 1.32 g /m$m^2$ in the Z. japonica grassland and 3. 08 g /m$m^2$in the M. sinensis grassland. For a case of steady production and release, the ratio of annual min- eral production to the amount accumulated on top of the mineral soil in a steady state provides estimates of the release constant k. The models of the release, accumulation and annual cycle of potassium in a grassland ecosystem are determined by the equation (1) to (3), respectively (Table 3). Since it requires a period of about each 0.693 /r, 3 /r and 5 /r years for the release and accumu-lation of 50, 95 and 99% of its steady-state level, the estimates for potassium in a dynamic grass-land ecosystem of Mt. Kwanak were 1.5, 6.6 and 11.0 years in the Z. japonica grassland, and were 2.7, 11.9 and 19.8 years in the M. sinensis grassland. The amounts of annual cycles for potassium in a grassland ecosystem under the steady-state conditions were 1.32 g /m$^2$ in the Z. japonica grassland and 3.08 g /$m^2$ in the M. sinensis grassland. Key words : ZQvsia japonica Ahscanthus sinensis, Mt. Kwanak, Potassium cycles.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.191-196
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• 2007

The Korean rural landscape has changed significantly due to nationwide modernization and industrialization in recent years. Moreover, as urbanization progresses due to population and economic growth, rural areas surrounding the suburbs of cities are feeling the pressure of encroaching urban sprawl. Use of land for human-made structures such as road and housing development is also increasing, resulting in the destruction of nature in rural areas. Adopting a concept of conserving rural landscape in future development projects is therefore highly desirable.The main focus of this study is to look into the traditional concept of the village and to classify some elements of the traditional rural landscape. Daegu Metropolitan City, the third metropolitan city in Korea, is chosen as the subject of the study. The existing 227 villages have been studied on the basis of their principles and types of village locations in relation to the traditional concepts of 'Feng-shui' and 'Tackriji'. The characteristics of the village location are divided into two aspects: the natural landscape, such as topography, hydrosphere, and azimuth, and the historical and cultural landscape, such as customs(Only the natural landscape aspect is included in this study). The natural landscape, a condition of the village location, is divided into three areas: topography, hydrosphere, and azimuth. There are two types of topography: flatland type and mountain type. There are two sub-types in the mountain type: ridge and valley, which depend on the village location in relation to the shapes of the mountains. There are four types of hydrosphere which include waterways and three directions of mountain depending on the shape: front, behind and side. The direction of the village is analyzed from the direction which the houses in the village face. Therefore, the natural landscape element as a condition of the village location is closely related to the traditional concepts of the village.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.771-776
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• 2008

The main purpose in having a control surface on a ship is to control the motion of it. It is the important element to determine the maneuvering characteristics of the ship. In this paper, the measured results has been compared with each other to predict the performance characteristics of flapped rudder's 2-dimensional section at $Re=3.0{\times}10^4$ using 2-frame grey level cross correlation PIV method. The side force of the rudder could be mainly improved by the lift force at 10 degrees angle of attack and the drag force at 20 degrees angle of attack. The separation point and boundary layer could be controlled by the change of the only flap's angle at 10 degrees angle of attack.

• Atmosphere
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• v.31 no.4
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• pp.421-431
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• 2021

The Yeongdong region is frequently vulnerable to heavy snowfall in winter in terms of societal and economical damages. By virtue of a lot of previous efforts, snowfall forecast has been significantly improved, but the performance of light snowfall forecast is still poor since it is very conducive to synoptic and mesoscale interactions, largely attributable to Taeback mountains and East Sea effects. An intensive observation has been made in cooperation with Gangwon Regional Meteorological Office and National Institute of Meteorological Studies in winter seasons since 2019. Two distinctive Cold Air Damming (CAD) events (14 February 2019 and 6 February 2020) were observed for two years when the snowfall forecast was wrong specifically in its location and timing. For two CAD events, lower-level temperature below 2 km ranged to lowest limit in comparisons to those of the previous 6-years (2014~2019) rawinsonde soundings, along with the stronger inversion strength (> 2.0℃) and thicker inversion depth (> 700 m). Further, the northwesterly was predominant within the CAD layer, whereas the weak easterly wind was exhibited above the CAD layer. For the CAD events, strong cold air accumulation along the east side of Taeback Mountains appeared to prevent snow cloud and convergence zone from penetrating into the Yeongdong region. We need to investigate the influence of CAD on snowfall in the Yeongdong region using continuous intensive observation and modeling studies altogether. In addition, the effect of synoptic and mesoscale interactions on snowfall, such as nighttime drainage wind and land breeze, should be also examined.

• Journal of The Geomorphological Association of Korea
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• v.25 no.4
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• pp.37-47
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• 2018

Coastal sand dunes have been regarded as natural defenses to protect hinterland from disasters such as storm surge and typhoons. However, many dunes are not well-deserved in South Korea because of imprudent land development or inappropriate measures after coastal erosion. Lately, beach nourishment and dune reinforcement are emphasized as the effective and environmentally sustainable solution for the coastal protection. They are regarded good strategies to keep landscapes for a time, with little side effects. However, there is little knowledge on the construction methods including proper design and time plans for the best results.In addition, the effects of dune reinforcement in the field should be tested.In thisstudy, we performed sand filling in an eroded dune scarp and surveyed topographic changes in the beach-dune system, which is located along Dasa-ri coast, Chungnam Province, South Korea. Using a network RTK-GPS and drone-based aerial photographs, we analyzed the temporal and spatial changes in the area, before and after the reinforcement. As a result, the dune reinforcement seems to be helpful to mitigates the coastal erosion and to prevent the coastline retreat at least for one year.

• The Journal of Sustainable Design and Educational Environment Research
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• v.20 no.1
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• pp.1-10
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• 2021

Elementary schools in Korea need to create an environment for integrated education and transform into school facilities that are central to the local community. This study assessed the level of universal design application in the physical environment of elementary schools based on the seven principles of universal design in order to create an environment in which all users, including elementary school students, can access and use school facilities equally. For this aim, field research was conducted on 243 elementary schools, and facilities with low application level were analyzed. As a result of the analysis, in order to apply the principle of 'flexibility in use', the rotating handle on the side of the toilet, which is used by the wheelchair user in the way the toilet is accessed, must be installed in a top-to-bottom rotational manner. In order to improve the applicability of the 'low physical effort' principle, it is necessary to select land and apply the plan from the beginning of the design.

• Journal of the Korea Institute of Building Construction
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• v.21 no.6
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• pp.629-640
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• 2021

According to statistics from the Ministry of Land, Infrastructure and Transport in 2018, approximately 37% of residential buildings in Korea need to be reconstructed. Due to the rapid growth of the demolition industry, many side effects such as environmental destruction and safety accidents are becoming a problem in the demolition of existing buildings. This study proposes a decision-making process for selecting the most suitable dismantling method for field application by comprehensively considering safety, economic feasibility, and environmental characteristics. In particular, field applicability is evaluated by evaluating risk factors for the selected method. To this end, this study proposes the TOPSIS method for the selection of the dismantling method using the QFD development concept, and the FMEA method as a continuous development process of the selected method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.161-163
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• 2021

This urban centralization is expected to develop rapidly, with 75% of the population living in the city by 2035. Large cities are becoming unsustainable due to side effects such as environmental pollution, severe traffic jams, excessive energy depletion, and destruction of the natural ecosystem. In addition, the happiness index of citizens of large cities is also falling because of high crime rates and safety accidents, the work-life imbalance caused by inequality and polarization, and overly competitive education. To solve this problem, Smart City, an IT-based future city model, was born. The Korean government is also actively attempting to improve urban competitiveness and promote sustainable development through efficient construction and operation of smart cities as a national focus project. To support the effort, we review the basic directions and strategies of Sejong City's Smart City service infrastructure based on the comprehensive national land plan, Smart City plan, and Smart City strategy plan.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.3A
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• pp.277-286
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• 2010

Derrick or caterpillar crane is generally used for the long-span/cable-stayed bridge construction by pre-cast segment lifting from over-land or water transportation. The heavy weight of them, however, could make defects on unstable under-construction structure and, furthermore a method of conventional segment transportation is also able to occur additional time and cost. In this study, in order to improve conventional construction method, the newly developed derrick crane is mainly considered. It could be not only eccentrically loadable on constructing girder but having rotatable boom for segment transportation from back-side. A series of construction stage using developed derrick crane is defined and also its numerical analysis is conducted. To reflect load characteristics of developed derrick crane on construction stage analysis, on/out of service load is separately calculated by considering vertical/lateral rotation range of boom and it is loaded on 4 fixed positions of crane. The derrick crane on this study could be time and cost saving solution for cable-stayed bridge construction and also make contributions to construction load reduction in its process.

• Korean Journal of Environment and Ecology
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• v.31 no.3
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• pp.337-343
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• 2017

This study is going to contribute the activation of ecosystem services written in the 3rd National Basic Plan for Nature Conservation(2016~2025) in Korea. Meanwhile we considered the benefits that the nature has given to the humankind as free goods or services which we may consume traditionally without due payment therefore. But on account of the expansion of cities and expedition of development, as the carrying capacity of the nature has been breached, people have come to try to restore and enhance artificially such vulnerable capacity. It is necessary to compensate the opportunity cost which the land owners or occupiers have to pay for conservation and maintenance of natural capitals which yield the ecosystem services. Therefore the institutionalization of ecosystem services should be established that the consumers who enjoy such services should share the interest from enjoying services with the land owners or occupiers who produce the ecosystem services, under the legal system which will make it possible to connect the benefit sharing with the conservation of environment. However it is the first task that the present legal system could not realize the fair and equitable benefit sharing between the producers and consumers of ecosystem services. And the second task in such legal system is that the value of ecosystem services could not be fully considered in the process of development planning. According to the analysis of this study, the institutionalization of ecosystem services in the government side and the civilian side could be realized to somewhat extent, although not sufficient. Especially the transactions of ecosystem services through the private contract among stakeholder are possible in the course of development planning or without any relevancy to a development project. The final task in the institutionalization of ecosystem services is how to assess the ecosystem services and to value the economic benefits therefrom on the basis of what kinds of procedures relating to some development processes. To overcome such difficulties, it is necessary that the state, trend and change of ecosystem services confronting with a developing project should be assessed concretely at the threshold of development. It is possible to integrate the ecosystem services into the environmental impact assessment(IEA), not by way of the Act of IEA, but by way of the Decree thereof.