• Korean Security Journal
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• no.32
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• pp.95-122
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• 2012

The ocean in the 21st century is getting emphasized as a treasury of natural resources and a growth engine for the nation. And nations around the world have entered into the hyper-competition to take the initiative for those marine resources. Under the situation, the Korea Coast Guard is devoting itself with full force to protecting maritime sovereignty, ensuring maritime safety and security and preserving the marine environment. Purpose of this study is to analyze Maritime Policing Act of 2012 and their problems and to suggest improvement measures. Objectives of Maritime Policing Act of 2012 is national Defence, policing for maritime security, protection of marine natural resources and marine facility in territorial waters and exclusive economic zone(EEZ) of Korea. Limits of Maritime Policing Act of 2012 are as follows. First, As organization related rules in Maritime Policing Act of 2012 are not enough, Maritime police agency Act should be revised and enacted in order to cope with future administrative demands and legal ground. Second, Article 22 penal regulation is more severe than regulations of another Act. Third, Article 14 should be made improvement for pre-prevention through the pre-report and the establishment of prohibition boundary in maritime demonstration.

• Korean Journal of Ecology and Environment
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• v.48 no.1
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• pp.38-50
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• 2015

Appearance patterns of freshwater fish were investigated in the western Demilitarized Zone (DMZ) adjacent areas near Imjin River in Gyeonggi-do, Korea, of 2014. A total of 61 species belonging to 14 families were found in the river during the survey. The dominant and subdominant species were Zacco platypus (Relative abundance, 20.3%) and Zacco koreanus (12.6%), respectively. Other abundant species include Rhinogobius brunneus (9.2%), Pungtungia herzi (4.4%), Acheilognathus yamatsutae (4.4%), and Pseudogobio esocinus (4.0%). Among the residing species, 24 species (39.3%) were endemic to Korea; and 1 species, Carassius cuvieri, was non-indigenous species. Hemibarbus mylodon is a natural monument, and Lethenteron reissneri, Acheilognathus signifer, Pseudopungtungia tenuicorpa, Gobiobotia brevibarba, G. macrocephala, and G. naktongensis are endangered species in Korea. In addition, Anguilla japonica and Plecoglossus altivelis are catadromous and amphidromous species, respectively. Among the investigated sites, the lower part of Sami Stream (St. 5, 6) and Gunnarm-dam region (St. 11, 14) are particularly valuable for the conservation of species diversity, because many fish species (33~42 species) including a natural monument and several endangered species inhabit in these regions.

• Korean Journal of Environment and Ecology
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• v.35 no.2
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• pp.135-153
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• 2021

The demilitarized zone (DMZ) is a border barrier with 248 kilometers in length and about 4 kilometers in width crossing east to west to divide the Korean Peninsula about in half. The boundary at 2 kilometers to the south is called the southern limit line. The DMZ has formed a unique ecosystem through a natural ecological succession after the Armistice Agreement and has high conservation value. However, the use of facilities for the military operation and the unchecked weeding often damage the areas in the vicinities of the southern limit line's iron-railing. This study aimed to prepare basic data for the restoration of damaged barren vegetation. As a result of classifying vegetation communities based on indicator species, 10 communities were identified as follows: Duchesnea indica Community, Hosta longipes Community, Sedum kamtschaticum-Sedum sarmentosum Community, Potentilla anemonefolia Community, Potentilla fragarioides var. major Community, Prunella vulgaris var. lilacina Community, Dendranthema zawadskii var. latilobum-Carex lanceolata Community, Dendranthema zawadskii Community, Plantago asiatica-Trifolium repens Community, and Ixeris stolonifera-Kummerowia striata Community. Highly adaptable species can characterize vegetation in barren areas to environment disturbances because artificial disturbances such as soil erosion, soil compaction, topography change, and forest fires caused by military activities frequently occur in the barren areas within the southern limit line. Most of the dominant species in the communities are composed of plants that are commonly found in the roads, roadsides, bare soil, damaged areas, and grasslands throughout South Korea. Currently, the vegetation in barren areas in the vicinities of the DMZ is in the early ecological succession form that develops from bare soil to herbaceous vegetation. Since dominant species distributed in barren land can grow naturally without special maintenance and management, the data can be useful for future restoration material development or species selection.

• Korean Journal of Environment and Ecology
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• v.17 no.1
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• pp.83-91
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• 2003

This study was conducted to clarify the characteristics of bird communities due to different habitat types on 3 sites in Han river area from May 2001 to January 2002. Water area was the most dominant habitat type in each site and also forest was dominant habitat type in site 1(Paldang area). Site 2(Bam island area) had various habitat types e.g. shrub field sandv plain, reed bed and grass field. Total 52 bird species were recorded on 3 sites in Han river. Ducks were the most dominant species, especially in January 2002. Density of individuals were higher in site 1 and 2, but lower in site 3(Nanjido area). In January 2002, dabbling ducks were dominant in site 2, and diving ducks were in site 1. Among diving ducks, common merganser Mergus merganser showed high density in site 2 and pochard Aythya ferina did in site 1. In site 1, coot Fulica atra showed also high density Diverse habitat types could be support foraging resources for dabbling ducks in site 2. High density of pochard and coot would be related to abundant aquatic plants and stable water depth in site 1. Manipulation of riparian zone in site 3 into natural vegetation would increase the bird species diversity. By the manipulation of habitat, habitat potentiality of birds would be increase in Han river area.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.586-594
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• 2017

This study was carried out to identify the potential protected areas recognized by experts to conform to the international definition of protected areas for effective implementation of CBD Aichi Target-11. A policy forum of 13 experts on the protected area was formed and conducted four forums, two surveys, and examination in the context of international perspective to identify four potential protected areas including the water source protection area, riparian buffer zone, fishery resources protected area, and urban natural park area. Excluding the existing protected areas, the total size of the potential protected areas was about $5,643.9km^2$ composed of the terrestrial areas of $3,117.9km^2$ and the marine areas of $2,526km^2$. As such, we can expect the expansion of coverage of national protected areas by up to 3.11% of the terrestrial land and up to 0.67% of the terrestrial marine area. This study is meaningful in that it provides the fundamental information to achieve the national target of protected areas in response to CBD Aichi Target-11. Further research on improving the protected areas qualitatively and quantitatively and identifying and linking with other effective regional OECM are required to enhance the national protected area system.

• Korean Journal of Environment and Ecology
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• v.22 no.5
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• pp.505-513
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• 2008

The purpose of this study is to analyze the distribution patterns and characteristics of plant species by human impact in urban areas. In order to achieve a comprehensive data acquisition of all autogenously introduced vascular plant species occurring in the city of Cheon-ju, this study made an analysis of 106 sample plots, each with a size of one hectare, These sample plots were selected to represent the typical land-use patterns within the city of Cheon-ju and to cover the various distances from the city center. Species richness, patterns of life forms, and the percentage of non-native species were analyzed in relation to the degree of hemeroby of the sample plots. It was found that the species number appeared the largest in sites that were moderately influenced. This result corresponds to the intermediate disturbance hypothesis that moderate disturbance leads to an increase in species richness. The flora of sites which were subject to the highest level of human impact, was characterized by a high proportion of annual species and non-native species. In addition, some species were divided into three groups with similar distribution corresponding to land-use type and urban zone: urbanophobic (e.g. Indigofera kirilowii, Prunus sargentii, Rhus trichocarpa), urbanoneutral (e.g. Commelina communis, Erigeron annuus, Metaplexis japonica) and urbanophilus (e.g. Euphorbia supina, Senecio vulgaris, Taraxacum officinale).

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.890-899
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• 2014

Austenitic stainless steel is widely used in various industries due to its excellent corrosion resistance. However, Cr carbides precipitation along the grain boundaries after heat treatment or welding may develop Cr depleted zone, which acts as a preferential site for intergranular corrosion attack. To resolve this, carbon stabilizing element such as Ti or Nb are added to suppress formation of Cr carbides. However, there are few reports on corrosion characteristics under seawater environment of the stabilized stainless steel. This study investigated the effects of alloying contents on the electrochemical characteristics in seawater of stainless steel containing stabilizing element(Ti and Nb). To achieve this, the changes on the microstructure due to alloying were observed with microscope, and the electrochemical characteristics were determined by measurement of natural potential and potentiodynamic polarization experiments. The microscopic observation revealed that all specimens had inclusions other than the austenite matrix phase due to the addition of alloying elements. Such inclusions are considered to have different electrochemical characteristics from those of the matrix, and thus a clear distinction was found according to the type of stabilizers and the contents. The results of this study suggest that it is important to consider the effects of alloying contents on the electrochemical characteristics in seawater with the addition of Ti or Nb into austenitic stainless steel.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.25 no.2
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• pp.26-41
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• 2020

In order to culture a life for the physiological and ecological research of the meiofauna, this study aimed to identify the most ideal condition in which the meiofauna can be cultured within a laboratory by setting various environmental conditions. The sediment deposits and seawater were collected from the intertidal zone in Mallipo of the west coast. A aquarium in which the internal environment can be controlled by constantly maintaining the temperature and humidity was fabricated and the culture experiments of the collected meiofauna were conducted together with the sea water and sediment deposits collected. The experiment 1 was conducted after establishing the similar environment as the collecting location. Under the same condition as the experiment 1, the experiment 2 verified a difference between when live foods were supplied and were not. In the experiment 3, the changes in the meiofauna colony were checked according to with or without light and live foods. In the results of culturing experiments, the habitat density and the number of appeared classification groups of the meiofauna colony were relatively higher both in the water tank with supplying the live foods and under the condition of having light in 12-hour cycle than those in the aquarium without live foods and under no light condition. In addition, the habitat density of meiofauna cultured within a laboratory exhibited relatively higher value than that under the natural state.

• Journal of Korean Society of Forest Science
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• v.101 no.4
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• pp.579-591
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• 2012

Berchemia berchemiaefolia is a rare and endangered species and important as a honey resource. The purposes of this study were to investigate physical environmental factors and the population and community structure of Berchemia berchemiaefolia stands at Mt. Gunja in Sogrisan National Park in Chungcheongbuk-do. The B. berchemiaefolia stands belonged to deciduous forests in mid-temperate zone and were $5{\sim}25^{\circ}$ in slope, 30~90% in rock ratio, and 6.37 in soil pH. They had 656 trees within the area of 36 ha and their average density was 18.2 trees per ha. The trees within the stands were 11.8 m in tree height, 22.6 cm in DBH and 56 years old. The number of branched stems was the maximum 8 and 32.9% of the trees were branched. B. berchemiaefolia trees over 12 cm diameter occupied 89.9%, but young B. berchemiaefolia did only 11%. The structure of B. berchemiaefolia stands were classified into three groups as Acer pseudo-sieboldianum & A. mono community group, A. pseudo-sieboldianum & Quercus aliena community group, and B. berchemiaefolia & Quercus serata community group. The mean importance value of B. berchemiaefolia was 10.9%, while species diversity of the community ranged 0.77~1.31 and interspecific competition ranged 0.78~0.94. The dominance of the community ranged of 0.07~0.29 and the evenness ranged 0.71~0.93. Although B. berchemiaefolia was dominant in the habitat, but the species was already in natural successional stage to Cornus controversa or Ulmus davidiana var. japonica.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.7
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• pp.779-785
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• 2015

Cathodic protection is recognized as the most cost-effective and technically appropriate corrosion prevention method for the submerged zone of offshore structures, ships, and deep-sea facilities. When cathodic protection is applied, the cathodic currents cause dissolved oxygen reduction, generating hydroxyl ions near the polarized surface that increase the interfacial pH and result in enhanced carbonate ion concentration and precipitation of an inorganic layer whose principal component is calcium carbonate. Depending on the potential, magnesium hydroxide can also precipitate. This mixed deposit is generally called "calcareous deposit." This layer functions as a barrier against the corrosive environment, leading to a decrease in current demand. Hence, the importance of calcareous deposits for the effective, efficient operation of marine cathodic protection systems is recognized by engineers and scientists concerned with cathodic protection in submerged marine environments. Calcareous deposit formation on a marine structure depends on the potential, current, pH, temperature, pressure, sea-water chemistry, flow, and time; deposit quality is significantly influenced by these factors. This study determines how calcareous deposits form in sea water, and assesses the interrelationship of formation conditions (such as the sea water temperature and surface condition of steel), deposited structure, and properties and the effectiveness of the cathodic protection.