• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.3
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• pp.201-210
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• 2005

This study was conducted to prepare efficient and systematic measures for nature conservation and management in Beomseom Islet, and to provide for basic data to investigate the process of vegetation change in the future. The vegetation of Beomseom Islet was classified to six vegetation type; i.e., Miscanthus sinensis community, Pinus thunbergii community, Iythophyte vegetation, evergreen broad leaf community, shrub community, and Pseudosasa japonica community. The size of each vegetation type was 40,230 $m^2$ ($23.3\%$) for shrub community, 39,366 $m^2$($22.8\%$) for Iythophyte vegetation, 30,012 $m^2$ ($17.4\%$) fur Pinus thunbergii community, 29,853 $m^2$ ($17.3\%$) for Miscanthus sinensis community, 5,564 $m^2$ ($3.2\%$) for evergreen broad leaf community, and 3,325 $m^2$ ($1.9\%$) for Pseudosasa japonica community. The area of non-vegetated sea cliff Bone that composed of bare rocks is 24,246 $m^2$($14.1\%$). We estimated that these distribution patterns of vegetation were the result of various environmental factors such as the steepness of slope and shallowness of soil as well as the cultivation of exotic plants causing disruption of native vegetation.

• Journal of Ecology and Environment
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• v.33 no.1
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• pp.23-36
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• 2010

The Cat Ba Islands in Hai Phong City, northern Vietnam, consist of a large limestone island with a maximum height of 322 m above sea level and 366 small limestone islets with a total area of about $180\;km^2$. The islands are relicts of karst limestone mountains that became submerged during the Holocene transgression 7000 - 8000 year ago. The combination of the longtime karst process and recent marine processes in the monsoonal tropical zone has created a very diversity landscape on the Cat Ba Islands that can be divided into 3 habitat types with 16 forms. The first habitat type is the karst mountains and hills, including karst mountains and hills, karst valleys and dolines, karst lakes, karst caves, and old marine terraces. The second habitat type is the limestone island coast, including beaches, mangrove marshes, tidal flats, rocky coasts, marine notch caves, marine karst lakes, and bights. The third habitat type is karst plains submerged by the sea, including karst cones (fengcong) and towers (fengling), bedrock exposed on the seabed, sandy mud seabed, and submerged channels. Like the landscape, the biodiversity is also high in ecosystems composed of scrub cover - bare hills, rainy tropical forests, paddy fields and gardens, swamps, caves, beaches, mangrove forests, tidal flats, rocky coasts, marine krast lakes, coral reefs, hard bottoms, seagrass beds and soft bottoms. The ecosystems on the Cat Ba Islands that support very high species biodiversity include tropical evergreen rainforests, soft bottoms; coral reefs, mangrove forests, and marine karst lakes. A total of 2,380 species have been recorded in the Cat Ba Islands, included 741 species of terrestrial plants; 282 species of terrestrial animals; 30 species of mangrove plants; 287 species of phytoplankton; 79 species of seaweed; 79 species of zooplankton; 196 species of marine fishes; 154 species of corals; and 538 species of zoobenthos. Many of these species are listed in the Red Book of Vietnam as endangered species, included the white-headed or Cat Ba langur (Trachypithecus poliocephalus), a famous endemic species. Human activities have resulted in significantly changes to the landscape end ecosytems of the Cat Ba islands; however, many natural aspects of the islandsd have been preserved. For this reason, the Cat Ba Islands were recognized as a Biological Reserved Area by UNESCO in 2004.

• The Korean Journal of Community Living Science
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• v.17 no.3
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• pp.15-28
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• 2006

This study is on the kindergarten uniforms in Changwon, south Gyeongsang province. The first part of this research is on whether or not students should wear uniforms and how often they should wear uniforms. The research also deals with what types of uniforms are required, how much they should cost and their size. Fifty one preschools including kindergarten and nursery were targeted for this research. The second part of the research is on the discrepancy of the labeled size and the actual size of the child. The results of the first part are as follows: A total of 46 out of 51 places adopted uniforms for their children. Sports wear style is the most popular for spring, fall and summer uniforms. For wearing frequency of kindergarten uniforms, 26 (61%) places allowed the students to wear uniforms for special events such as picnics or observation trips 17(34%) places had the students wear their uniforms on a daily basis and 2 3 times only wearing a week.'rho preschool children interviewed for this study were from 2 to 5 in lull age. However, sizes with high frequency rates were 9 to 11 and the supplied sizes of uniforms were from 5 to 17. The results of the second part are as follows: The bust girth and the shoulder width of upper garments of uniforms are bigger than children's physical size, while clothes length and sleeve length are relatively shorter. Also the bust girth of upper garments of uniforms differs in the size depending on each preschool. The waist girth and the total length of lower garments of uniforms are made smaller than children's physical sizes, while hip girth is relatively larger. In the case of lower garments, the rest parts of cloth length are smaller than upper garments of uniforms. Also, the waist girth and hip width of uniforms are smaller than those of lower garments In summer garments, while thigh width is similar in both cases. The waist width is made too small. Described in the above excluding the waist width, the rest parts are relatively larger than children's physical sizes, but shorter in the length. Due to the length, children at age 7 may wear uniforms in the level of 17. Since summer uniforms touch the students' bare skin, the rest parts excluding clothes length are shorter than these of the spring and fall uniforms. In the case of clothes length, it seems to be due to different designs. The waist width of lower garments in all the uniforms tested in this study is too small for children, requiring them to be made in a larger size.

• Journal of Korean Society of Steel Construction
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• v.15 no.1
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• pp.87-96
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• 2003

The Ssteel-Cconcrete (SC) Ccomposite Ccolumn is a new Ccomposite Ccolunin system, where hoops are welded between flanges of H-shapesd steel and concrete is filled in spaces between flanges are filled with con crete. Tests of SC composite columns were performed previously to determine their compression, bending and shear strength, and it showed good structural behavior. But sSince a column is usually subjected to an axial compression force, and bending it ihas needed to be bent forevaluate its structural behavior to be evaluated when its axial load and bending isaresimultaneously applied to the SC composite column. In this paper, tests were conducted to investigate the bending strength of SC composite columns subjected to axial compression force and bending moment. The parameters of the tests were concrete, a stud bolt, a hoop and a magnitude of axial compression. The test results showed that the maximum bending strength and ductility of an SC composite column were increased by 33-42% and 33-63%, respectively, comparinged to those of a bare steel column. Also, the results obtained bywith the Korean Limit State Design Code (LSD) presents a considerably safe side value compared to those of the Eurocode-4 and the Japan Code. However, wWhen the axial compression force is was increased, however, there awere considerable differences between the maximum strength obtained by the test and the LSD analysis. For this reason, it is recommended tothe use of the Eurocode-4 is recommended when calculates the strength of an SC composite column is being calculated, since the Eurocode-4 gives us a better estimation.

• Journal of Korean society of Dental Hygiene
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• v.9 no.1
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• pp.125-139
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• 2009

Objective : This study was performed in order to provide basic data for halitosis prevention and establish a device to efficiently eliminate halitosis and to analyze the factors that affect the halitosis. Methods : Oral examination on the Gingival index, CPITN, Tongue Plaque index, and OHI-S as well as halitosis measurement among 293 rural residents. Results : Gingival index was high at mild on female and at moderate on male(p=0.025). Sorting the result by age, mild was 54.1% in the 40s, and moderate was 49.5%, 42.0% and 70.0% each in the 50s, 60s, and the 70s(p=0.005). The need for dental plaque management was 100%. The need for scaling was high with 78.3%, 93.0%, 89.9%, and 90.0% each for the 40s, 50s, 60s, and 70s. The need for complex periodontal treatment was also high with 32.4%, 47.5%, 48.7% and 60.0%, each for the 40s, 50s, 60s, and 70s(p=0.050). The highest bad condition for OHI-S was 69.5%, and good being 18.9%, and very bad being 11.6%. For moderate tongue plaque index was 74.4% as the highest. As the level of education increased, the slight tongue plague was increased, but in contrast, the moderate and higher tongue plague index was decreased(p=0.010). OG under 50ppm was 61.1% on male and OG over 50ppm was 50.9% on female(p=0.041). In OG over 50ppm, CPITN was 52.1% and 41.9% in scaling and complex periodontal treatment group(p=0.018). OHI-S, in bad and very bad condition with OG, over 50ppm, was 48.7% and 46.9%(p=0.019). The higher tongue plague index showed significant amount of increase at OG and EG above 50ppm(p=0.006). $NH_3$, as the tongue plaque index increased, the wider range of distribution was shown(p=0.000). As for the multiple regression analysis result, there have been selected females and tongue plaque index as factors affecting OG. There have been selected age and tongue plaque index as factors affecting EG and there have been selected females as factors affecting on $NH_3$. Conclusions : With the aforementioned results in mind, the status of halitosis among rural residents is considered to bare a close relation with oral environments. we have to focus on correct tooth brushing methods and tongue brushing, with using tongue cleaner to remove fur of tongue plaque. Also, in order to analyze exactly the factors of individual halitosis, we need continuous and systematic study.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.1-19
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• 2017

This study set out to identify problems with amphibian habitation by the wetland types and improve their habitation environment in urban forest wetlands, thus creating a habitat for amphibians. Study site include forest swamps in Jatjul Park as well as Yeoji neighborhood Park in Guro-gu, and in Choansan neighborhood Park in Dobong-gu. The forest swamp in Jatjul Park gets its water from Mt. Maebong and it is a former escalated farmland-turned wetland. The swamp area is $2,500m^2$, a forest zone and a landscape planting site are 83.27% and 6.70% each. Target species Seoul pond frogs are inseparable from rice fields because they live in a short radius of and lay eggs in or near paddy fields, and Rana nigromaculata have similarities with Rana plancyi chosenica in choosing their habitats. There was need for paths that would lead to other paths so amphibians would spread to other parts of the forest and for measures to secure open water. Modifying a variety of routes for water, human and animals along with building a buffer to keep the core habitation zones were required. The forest swamp in Yeonji neighborhood Park used to be a water reservoir on the foot of Mt. Gunji. The swamp area is $1,980m^2$, a forest zone and farmland account for 80.61% and 4.88% each. Non-point pollutants from upstream along run into the subject forest marsh, bare ground on the around swamp and steep stone embankments obstructed amphibians. Target species was Bufo gargarizans that live in forests and edges of hills and spawn in deep water. The forest swamp in Choansan neighborhood Park gets its water from Mt. Choan and it is close to its water source that it is a mountain stream forest wetland. The basin and the swamp are $35,240m^2$ and $250m^2$ in size respectively. A forest zone accounts for 90.20%, high stone embankments laid in refurbishing the valley obstruct amphibians and there is water shortage in times of droughts. Target species were Rana coreana, Rana dybowskii and Hynobius leechii that live in mountain valleys, streams and wetlands and lay eggs in forest marshes and rocks in valleys. Looking into the three swamps of amphibian habitation, I came to conclusions that those wetlands were suitable for their amphibians but man-made facilities blocked their corridors leading to other corridors and even killed off target species in some parts of those swamps by destroying those parts. Amphibians live in water, on ground and underground at different stages of life. Hence, we should take this fact into consideration when planning their habitats and design core habitation zones, buffers zone and use zones accordingly. Buffer zones ought to be between core habitation zones and surrounding trees. Aiming at protecting core habitation zones, buffers should be in harmony with habitation zones. Use zones should be minimized in size and not in direct contact with core habitation zones.

• Journal of Powder Materials
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• v.22 no.5
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• pp.321-325
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• 2015

The triboelectric property of a material is important to improve an efficiency of triboelectric generator (TEG) in energy harvesting from an ambient energy. In this study, we have studied the TEG property of a semiconducting $SnO_2$ which has yet to be explored so far. As a counter triboelectric material, PET and glass are used. Vertical contact mode is utilized to evaluate the TEG efficiency. $SnO_2$ thin film is deposited by atomic layer deposition on bare Si wafer for various thicknesses from 5.2 nm to 34.6 nm, where the TEG output is increased from 13.9V to 73.5V. Triboelectric series are determined by comparing the polarity of output voltage of 2 samples among $SnO_2$, PET, and glass. In conclusion, $SnO_2$, as an intrinsic n-type material, has the most strong tendency to be positive side to lose the electron and PET has the most strong tendency to be negative side to get the electron, and glass to be between them. Therefore, the $SnO_2$-PET combination shows the highest TEG efficiency.

• Journal of Korea Multimedia Society
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• v.16 no.6
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• pp.720-734
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• 2013

In this paper, we suggest an augmented reality authoring tool system that users can easily make augmented reality contents using hand gesture and marker-based interaction methods. The previous augmented reality authoring tools are focused on augmenting a virtual object and to interact with this kind of augmented reality contents, user used the method utilizing marker or sensor. We want to solve this limited interaction method problem by applying marker based interaction method and gesture interaction method using depth sensing camera, Kinect. In this suggested system, user can easily develop simple form of marker based augmented reality contents through interface. Also, not just providing fragmentary contents, this system provides methods that user can actively interact with augmented reality contents. This research provides two interaction methods, one is marker based method using two markers and the other is utilizing marker occlusion. In addition, by recognizing and tracking user's bare hand, this system provides gesture interaction method which can zoom-in, zoom-out, move and rotate object. From heuristic evaluation about authoring tool and compared usability about marker and gesture interaction, this study confirmed a positive result.

• Bulletin of the Society of Naval Architects of Korea
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• v.22 no.2
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• pp.35-48
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• 1985

The present work develops a method of evaluating thrust deduction and wake for different loads of the propeller using the concerted application of the theoretical tools and experimental techniques. It also shows the applicability of the new method to the design of optimum hull form. Firstly, the problem of hull-propeller interaction was analyzed in terms of inviscid as well as viscous components of the thrust deduction and wake. The wavemaking resistance of a hull and propeller were mathematically represented by sources on the hull surface and sink on the propeller plane, respectively. The strength of sink was determined by utilizing the radial distributions of propeller load and nominal wake. The resistance increment due to a propeller and the axial perturbation flow induced by the hull in the propeller plane were calculated. Especially, the inviscid component of the thrust deduction was calculated by subtraction the wavemaking resistance of a bare hull, the wavemaking resistance of a free-running propeller and the augmentation of propeller resistance due to hull action from the wavemaking resistance of the hull with a propeller. The viscous components of the thrust deduction and wake were estimated as functions of propeller load which were established by the propeller load varying test after deduction the calculated inviscid components. Secondly, an analysis method of powering performance was developed based on the potential theory and the propeller load varying test. The hybrid method estimates the thrust deduction, wake and propeller open-water efficiency for different propeller load. This method can be utilized in the analysis of powering performance for the propeller load variation such as the added resistance due to hull surface roughness, the added resistance due to wind, etc. Finally, the hybrid method was applied to the optimum design of hull form. A series of afterbody shapes was obtained by systematically varying the waterplane and section shapes of a parent afterbody without changing the principal dimensions, block coefficient and prismatic coefficient. From the comparison of the predicted results such as wavemaking resistance, thrust deduction, wake and delivered power, an optimum hull form was obtained. The delivered power of the optimized hull form was reduced by 5.7% which was confirmed by model tests. Also the predicted delivered power by the hybrid method shows fairly good agreement with the test result. It is therefore considered that the new analysis method of powering performance can be utilized as a practical tool for the design of optimum hull form as for the analysis of powering performance for the propeller load variation in the preliminary design stage.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.353-359
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• 1996

Micro plot study was conducted to elucidate the behavior of nitrogen derived from animal manure in soil and to obtain the fundamental information on animal waste management. Soils used in this experiment were sandy loam and loam. Soil water samplers (1m length ceramic cup tube) were installed at 90cm depth of soil to collect the percolate. Fresh and fermented pig manure were applied at the rate of 0, 50, 100 ton per ha. Maize was grown to evaluate the effect of crop on nitrogen behavior through soil profile. Concentration of nitrate nitrogen in percolate increased by application of pig manure. This trend was more obvious at the loam with fermented pig manure than sandy loam with fresh pig manure treatment. The concentration of nitrate nitrogen was lower under the maize cultivation than bare soil condition by 64.6-68.9%. Concentration of Ca, Mg and Na of soil and percolate increased as nitrate nitrogen concentration increased. The equivalent ratio of cation to nitrate nitrogen of percolate was increased by application of pig manure. This result showed that canon leaching was accompanied by nitrate nitrogen. Concentration of nitrate nitrogen of subsurface soil was increased by pig manure application.