• Korean Journal of Ecology and Environment
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• v.48 no.2
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• pp.122-128
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• 2015

This study aims to figure out the vegetation status and characteristics of the spatial distribution in Taeanhaean National Park. As a result, vegetation communities were Pinus thunbergii community, Pinus densiflora community, Pinus thunbergii-Pinus densiflora community, Camellia japonica community, Carpinus turczaninowii community, Carpinus turczaninowii-Pinus thunbergii community, Kalopanax septemlobus community, Koelreuteria paniculata community, Robinia pseudoacacia community, and sand dune and coastal wetland vegetation including Vitex rotundifolia community, Elymus mollis community, Calamagrostis epigeios community, Ischaemum anthephoroides community, Zoysia sinica community, Suaeda maritima community, and Phragmites communis community. Landscape types in actual vegetation map were Pinus thunbergii community (3.92%), Pinus densiflora community (1.40%), Robinia pseudoacacia community (0.05%), sand dune and coastal wetland vegetation (0.11%), field (0.46%), seashore (0.24%), thinning area (0.08%), bareground (0.16%), and sea (93.58%). Area of Pinus thunbergii community among vegetation type was $14.797km^2$ (3.92%) and the largest. Stratification structure and species composition of Pinus thunbergii community distributed in the seashore were different as a result of disturbance and human use. On the other hand, we assumed that succession will take place to the potential natural vegetation that is Quercus serrata and Quercus dentata in undisturbed Pinus thunbergii community. Meanwhile, Erechtites hieracifolia was occupied in understory of Pinus thunbergii community around the seashore and Diodia teres was invaded to sand dune vegetation. They may affect on natural species negatively. Therefore, monitoring and management plans are necessary.

• Journal of The Geomorphological Association of Korea
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• v.21 no.4
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• pp.41-52
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• 2014

Coastal dune, as one part of beach system, contributes for beach recovery as well as preventing beach erosion by exchanging sands between beach and dune. Due to high tidal range, the boundary of sand dunes on the west coast of Korean Peninsula is outside the high water line during spring tide and erosion also occurs in high waves during spring high tide. This paper investigates the erosion status of the dunes located in the JangHang beach by analyzing images from camera monitoring system, and tide and wave data observed adjacent to the study site during the passage of 4 typhoons in 2012. It also studies the benefits of camera monitoring images in investigating the dune erosion and analyzing coastal topographic changes.

• Journal of the Korean Geographical Society
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• v.50 no.4
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• pp.375-391
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• 2015

Trees to arrest sand-shifting have been planted on most of coastal dunes in Korea and considered as conservative objects. However, we reconsider that the simplicity of these trees have hindered ecological roles of coastal dunes; geochemical cycle and habitats of endemic species in coastal ecosystem. We examined geochemical properties of sediments on Byunsuran dune field where is planted with pine trees. There are significant difference in properties between embryo dune sediments and foredune sediments, but there are not between foredune and secondary dune. There are no significant difference between pine forest sediments and mixed forest sediments. It is also not showed the difference between dune ridge sediments and swale sediments. Despite spatial diversity from appearance, geochemical properties are not linked with geomorphic and vegetational conditions because of dense planted trees on foredune. To recover natural properties of coastal dunes, we need to change the conservation scheme to increase geomorphic and ecological diversity.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.545-552
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• 2017

Aeolian dunes are typical sand dunes which are maintained and developed by interactions of earth surface, wind and vegetation. Developing a model which can predict the changing phenomena of these sand dunes is vital in enhancing the efficiency of understanding and management of terrains such as land degradation. In the existing models, however, there is lack of studies on the long - term behaviors of the sand dunes and application to actual topography. Therefore, this study applied the wind-vegetation model considering vegetation to the actual topography and analyzed the applicability of the wind-vegetation model by analyzing the long-term behaviors and comparing them with actual data. Through analysis, study found out that use of wind-vegetation model and data from unmanned aerial vehicle is effective in analyzing the changes of actual dune topography. Except for the boundary, the error of about 1m was generated compared with the change of the actual dune topography.

• Journal of Life Science
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• v.18 no.10
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• pp.1355-1359
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• 2008

Endophytic fungi predominantly inhabit grasses, and produce a variety of beneficial metabolites for plant growth, as well as help their hosts against pathogens and herbivores. Current study was focused on plant growth promoting activity of endophytic fungi inhabited in the roots of sand dune grasses. We collected 49 fungal isolates from the roots of four most common sand dune grasses and screened them for their growth promoting capacity. Results showed that 37 fungal isolates (75.5%) promoted plant height and shoot length of waito-c rice, 11 fungal isolates (22.5%) suppressed it, while 1 fungus (2%) showed no effect on the growth attributes. The fungal strain Gibberella fujikuroi, along with distilled water and Czapek broth medium, were taken as control for this experiment. It was concluded that a major proportion of endophytic fungi inhabited in the sand dune plants produce metabolites, and thus help in growth and development of the host plant.

• Structural Engineering and Mechanics
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• v.53 no.6
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• pp.1241-1251
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• 2015

Faced with the growing needs of material resources and requirements of environmental protection for achieving sustainable development, it has become necessary to study and investigate all possibilities of exploring crushed and dune sand, reusing industrial wastes and by-product, and also applying new technologies including sand concrete which can replace the conventional concretes in certain structures to surmount the deficit on construction materials, conserve natural resources, lessen the burden of pollutants to protect the environment and reduce the consumption of energy sources. This experimental study is a part of development and valorization of local materials project in Skikda region (East of Algeria). It aims at studying the effects of partial replacement of sand with marble waste as fines on several fresh and hardened properties of sand concrete in order to reuse these wastes in the concrete manufacturing, resolve the environmental problems caused by them and find another source of construction materials. To achieve these objectives, an experimental program has been carried out; it was consisted to incorporate different percentages of marble waste fines (2, 4, 6, 8, 10 and 12%) in the formulations of sand concrete and study the development of several mechanical and rheological properties. We are also trying to find the optimal percentage of marble waste fine replaced in sand concrete that makes the strength of the concrete maximum. Obtained results showed that marble waste fines improve the properties of sand concrete and can be used as an additive material in sand concrete formulation.

• International Journal of Concrete Structures and Materials
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• v.3 no.1
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• pp.11-14
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• 2009

This paper is interested in the incorporation of crushed sand and desert sand in the composition the self compacting concretes (SCC). Desert dune sand, which has a fine extra granulometry, and the crushed sand, which contains an important content of fines, can constitute interesting components for SCC. Part II consists in studying the behaviour of SCC containing various sands with different origins. These sands, with different sizes, consist of several combinations of rolled sand (RS), crushed sand (CS) and desert sand (DS). The study examines the influence of the granular combination of sands on the characteristics in the fresh and the hardened state of SCC. The results of the experimental tests showed an improvement of the workability of the fresh SCC by combining sands of varied granulometry. The addition of the DS to CS or to RS allowed the increase of the mixture viscosity but decreased the mechanical strengths. Furthermore, the CS-RS combinations increased the compressive and the tensile strengths of the studied SCC. The optimized formulations of sands gave the highest performances of the SCC.

• Journal of the Korean association of regional geographers
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• v.22 no.4
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• pp.887-911
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• 2016

The empirical law that transverse dunes migrate inversely with their heights leads logically to the prediction that multiple dune ridges will converse to a single huge dune by merging. This contradicts the existence of the steady state dune fields on the Earth. The recent studies have emphasized dune collisions as a key mechanism to the stability of dunefield. The roles of wind shadow aspect ratio, however, have yet to be fully explored. This research aims to investigate the potential roles of wind shadow aspect ratio in the dynamical behaviors of transverse dune field. The simplified model is established for this, based upon allometric properties of transverse dunes, wind speedup on the stoss slope and sand trapping efficiency. The derived governing equations can be transformed to the zoning criteria and vector field for dune evolution. The dynamics analysis indicates that wind shadow aspect ratios do not produce convergent areas on the behavior space; rather, they just act as one of the factors that affect the trajectories of dune evolution. Though the model cannot represent the stability of dune field, but seem to produce a reasonable exponent for dune spacing-height relations.

• Water for future
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• v.25 no.3
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• pp.65-77
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• 1992

The purpose of this study is to analyse existing hysteresis models and to propose a new type of model. The existing hysteresis models are classified by three types: interpolation model, scaling model and domain model, of which the domain model is based on the theoretical approach. Models which need one branch of hysteresis loop for calibration are developed based on the independent domain concept, however, they are not successful to accurately simulate the real data and Rubicon Sandy Loam and Dune Sand. There is a possibility that a new model is based on the dependent domain model considering the pore blockage effect against air entry for homogeneous porous media(modelIII-1, Mualem, 1984). Concludingly, a new type of hysteresis model is proposed by simplifying ModelIII-1 using a proper assumption.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.69-79
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• 2012

The aim of this study is to analyze the mid-term changes of beach and dune morphology at Sohwang beach, Korea using by Total Station. Measurements executed 4 times during two year. Based on ArcInfo as point cloud obtained through precise measurement data by Total Station, alteration of beach and dune was analyzed at DEM, of which cell size is about 1m. Since these artificial constructions have influenced current systems of this region, the large-scale sand movements above mentioned have occurred around the jetty and the sea-wall. There occurred sedimentation in the north of the Jetty and erosion in the south of the Jetty, which is installed at the central part of object area. The direction of recent topographic development does not coincide with that of wind, and, rather, topographic changes occurred mainly at beaches and dunes due to the transformation of coastal water flow caused by artificial structure nearby. If precise measurement is conducted periodically, and long term monitoring is carried out by installing equipment measuring movement pattern of sediment around artificial structure, cause of topographic change around the object area could be discovered.