• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.5
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• pp.269-277
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• 2017

Recently, a submerged breakwater has been installing to prevent the erosion of shoreline everywhere. Artificially submerged breakwater is made to minimize the loss of nourishment sand beach erosion. For this reason, it has been indiscriminately constructed submerged breakwater that is planned in the country throughout. However, maintenance purposes to keep the shoreline of the beach is a method that is quite a few problems. There are also disadvantages such as expensive construction costs, ocean space utilization, water pollution and shoreline modification. In addition, person of utilizing the space of the ocean leisure does not like that because of the disconnection of ocean space. The beaches such as Gwanganri are artificially supplying nourishment sand to maintain the beach. The flexible construction method refers to a structure that is installed as a flexible material instead of submerged breakwater to prevent the loss of nourishment sand. In order to develop a new method to mitigate shoreline erosion, this study was carried out a hydraulic model experiment by installing a cell group as an example of the flexible method. Namely, in order to prevent the loss of nourishment sand, we decided to develop a new method that can mitigate the degree of beaches erosion by using cell group instead of submerged breakwater. In the two dimensional fixed hydraulic experiment, was carried out the effect reducing of wave height and the rate of low reflection due to the installation of the cell group. In movable bed experiment, the capture rate of the nourishment sand and the erosion prevention rate of the nourishment sand was performed for stability of shoreline. Therefore, according to the results of the hydraulic tests, it was possible to maintain the stable beaches due to installing the cell group on the erosion beaches, due to the effect of reducing wave height, the low reflection, the erosion prevention rate of nourishment sand, the high capture rate of nourishment sand.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.4
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• pp.86-99
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• 2016

This study was for analyzing the external environment and internal space structure and improving the way of use efficiency in waterfront through the Dragon boat festival to utilize waterfront actively. Through from the four target area, Hongkong, Busan, Incheon and Daejeon, this study was for an importance and satisfaction analysis for users about the element effect on the waterfront use efficiency and the contribution to cultural contents revitalization of waterfront by giving basic data. The result is as follows. First, in the importance analysis about 12 items, modern cultural infra around the waterfront was ranked highest, 8.26 and waterfront landscape, square & openspaces, convenience facilities, transport, green area, quality of viewing space, historic resources, pedestrian, suitability of width, wave, depth, water quality, berth & mooring were ranked in descending order. Second, waterfront landscape was interpreted by rather the external environmental impact according to city size than the matter of spatial structure in target area and judged as an important factor effect on site selection for waterfront. In the analysis of waterfront landscape, the reason of the high satisfaction about domestic target area was that riverside parks were recently made considering their waterfront activities. Viewing space was major infra where people could experience the pleasant waterfront and watch dynamic water leisure sports like Dragon boat three dimensionally and was thought to be improved for the use efficiency. Third, tourism resources were very important element that affect the use efficiency of waterfront, so waterfront users react sensitively to modern tourism resources rather than to historic resources. This meant that tourism infrastructure for shopping and leisure of the young affected the use efficiency of waterfront, so Hongkong and Busan were in a better position in terms of using waterfront that was near the tourism infrastructure. Fourth, in the analysis of traffic accessibility, both Hongkong and Busan were high evaluated in terms of excellent traffic accessibility by subway. Daejeon was low rated in terms of the satisfaction of use efficiency, because of the relative lower place awareness compared with transportation infrastructure. In Hongkong, waterfront was connected with downtown and in Busan, housing complex and shopping centers were located in the place for users in an easily accessible on foot, so the satisfaction was high-pitched. Finally, in the importance of water surface width and the analysis of satisfaction, except Incheon, all the three were over 200m in width of water surface and this meant the surface width above certain level was interpreted to interrupt the concentration of enjoying the water leisure sports. In the analysis of surface condition such as water quality, water depth and wave, through a survey, Busan had a problem with water quality and Gapcheon in Daejeon had a problem with optimal water depth by the festival participants.

• Journal of Wetlands Research
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• v.26 no.1
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• pp.41-50
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• 2024

Plant Microbial Fuel Cells (P-MFCs) are biomass-based energy technologies that generate electricity from plant and root microbial communities and are suitable for natural fundamental solutions considering sustainable environments. In order to develop P-MFC technology suitable for domestic waterfront space, it is necessary to analyze international research trends first. Therefore, in this study, 700 P-MFC-related research papers were investigated in Web of Science, and the core keywords were derived using VOSviewer, a word analysis program, and the research trends were analyzed. First, P-MFC-related research has been on the rise since 1998, especially since the mid to late 2010s. The number of papers submitted by each country was "China," "U.S." and "India." Since the 2010s, interest in P-MFCs has increased, and the number of publications in the Philippines, Ukraine, and Mexico, which have abundant waterfront space and wetland environments, is increasing. Secondly, from the perspective of research trends in different periods, 1998-2015 mainly carried out microbial fuel cell performance verification research in different environments. The 2016-2020 period focuses on the specific conditions of microbial fuel cell use, the structure of P-MFC and how it develops. From 2021 to 2023, specific research on constraints and efficiency improvement in the development of P-MFC was carried out. The P-MFC-related international research trends identified through this study can be used as useful data for developing technologies suitable for domestic waterfront space in the future. In addition to this study, further research is needed on research trends and levels in subsectors, and in order to develop and revitalize P-MFC technologies in Korea, research on field applicability should be expanded and policies and systems improved.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.797-807
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• 2011

Phenomenon of vegetation recruitment on the sand bar is drastically rising in the streams and rivers in Korea. In the 1960s prior to industrialization and urbanization, most of the streams were consisted of sands and gravels, what we call, 'White River'. Owing to dam construction, stream maintenance, etc. carried out since the '70s, the characteristic of flow duration and sediment transport have been disturbed resulting in the abundance of vegetation in the waterfront, that is, 'Green River' is under progress. This study purposed to identify the correlation among water level, water temperature, rainfall, soil moisture and soil texture out of the factors which give an effect on the vegetation recruitment on the sand bar of unregulated stream. To this purpose, this study selected the downstream of Naeseong Stream, one of sand rivers in Korea, as the river section for test and conducted the monitoring and analysis for 289 days. In addition, this study analyzed the aerial photos taken from 1970 to 2009 in order to identify the aged change in vegetation from the past to the present. The range of the tested river section was 361 m in transverse length and about 2 km in longitudinal length. According to the survey analysis, the tested river section in Naeseong Stream was a gaining river showing the higher underground-water level by 20~30 m compared to Stream water level. The difference in the underground water temperature was less than $5^{\circ}C$ by day and season and the Stream temperature did not fall to $10^{\circ}C$ and less from May when the vegetation germination begins in earnest. The impact factor on soil moisture was the underground water level in the lower layer and the rainfall in the upper layer and it was found that all the upper and lower layer were influenced by soil particle size. The soil from surface to 1 m-underground out of 6 soil moisture-measured points was sand with the $D_{50}$ size of 0.07~1.37 mm and it's assumed that the capillary height possible in the particle size would reach around 14~43 cm. On the other hand, according to the result of space analysis on the tested river section of unregulated stream for 40 years, it was found that the artificial disturbance and drought promoted the vegetation recruitment and the flooding resulted in the frequency extinction of vegetation communities. Even though the small and large scales of recruitment and extinction in vegetation have been repeated since 1970, the present vegetation area increased clearly compared to the past. It's found that the vegetation area is gradually increasing over time.

• Development and Reproduction
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• v.14 no.4
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• pp.281-286
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• 2010

Recent evidence has revealed that the intratesticular injection of hypertonic saline(20%) resulted in a chemically castrated state such as nadir testosterone levels in rats. To confirm the efficacy of this simple saline-injection method further, we investigated the changes in the gross and microscopic anatomy of testis. Our study comprised three groups; intact(control) group, orchidectomy group and saline-injection (experimental) group. Single dose of hypertonic saline (sterilized, $750{\mu}{\ell}/testis$) were directly administered into both testis of adult rats (about 300 g BW). Bilateral orchidectomy was performed at the same day of saline injection. Following 30 days post-injection, reproductive tissues were surgically removed, weighed and fixed for histological examination. The body weights were not changed in both orchidectomy group and saline-injection group when compared to those in intact group. The wet weights of testis were significantly decreased in saline-injection group when compared to those in intact group. The wet weights of epididymis and seminal vesicle and prostate were significantly decreased in orchidectomy group and saline-injection group when compared to those in intact group. Macroscopically, the testes exerted slight atrophy and the tunica albuginea seemed to be intact in saline injection group. Histologically, however, larger parts of testicular tissue underwent necrosis and were barely recognizable after hematoxylin-eosin staining. In the same section, only the opposite part of the injection site was stained showing abnormal state of cell layers mostly fibrosis and infiltrated leukocytes. Sloughing of immature germ cells from the basement membrane along with shedding cells in the intraluminal space was notable in most seminiferous tubules from the saline injected testis. The present study confirmed that the direct injection of hypertonic saline into testis can induce a castration-like, testosterone-depriving effects on accessory sex organs. Our findings suggest that the efficacy of this less expensive and minimally invasive method seems to be almost even with that of conventional orchidectomy and chemical castration, though more in-depth evaluation should be supported.

• Archives of design research
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• v.20 no.1 s.69
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• pp.5-20
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• 2007

The aim of this research is to find out the flows of mega-trends and design trends by analyzing the factors that influence trend and design trends in the late 20th century. Moreover, it is to forecast and recommend design color trends by evaluating color trends in design trends for the near future. Secondary and primary research were used in parallel. In the late 20th century, mega-trends were analyzed from secondary research based on PEST. Design trends were analyzed from case studies in fashion, space, product and visual design. On this basis, design color trends were analyzed. Also, color trends were forecast for the near future. The results are as follows. Firstly, the main trends in the late 20th century were 'female thinking', 'back to the nature' and 'heaven of peace'. Second, main design trends in the 1970s were modernism, post-modernism and high-tech. In the 1980s, with those of the 1970s, ecology was introduced In the late 1980s. In the 1990s, modernism rose again and ecology had an influence. The trends of 'female thinking' and 'back to the nature' controled the design in the early 2000s. Third, design colors in the late 20th century changed from Red to Purple Blue. Tones changed from 'grayish' to 'dull' Finally, it was forecast that Purple Blue, Yellow Red and Green colors with 'grayish', 'dull' and 'deep' tones were going to be used mainly in the near future. Also, achromatic colors with female and warm nuances would be reflected in design parts. This research will be very useful in that it has built a concrete database reflected on design trends forecasting in the near future by organizing academically a methodology to identify trends reflected on design and identifying relation between mega-trends and design trends based on analyzing factors that influence trend.

• Journal of the Korean Institute of Landscape Architecture
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• v.41 no.5
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• pp.78-90
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• 2013

The purpose of this study was to analyze the types and characteristics of public complaints caused by the landscape architecture projects in the case of apartment complex. Furthermore, its purpose was also to propose as the basis data for the minimization of complaints in the course of future landscape architecture projects. To analyze and categorize the apartment complex civil complaints, we collected basic and case study data from LH Corporation, SH Corporation and GICO from 2009 to 2012. We also categorized 672 landscape complaints to 73 categories and conducted a survey from residents and landscape architecture. This Survey is to use IPA can collect character(public-private), handling of civil affair(easy-hard) and analyze typical characters and difference of civil complaint awareness between landscape architecture and residents. First, we were categorized 73 civil complaints by type in 5 categories such as park, green space and street trees, pedestrian road, facilities, and others. Second, the most common landscape complaints appear in green spaces, street trees, facilities, pedestrian roads and park orders. Third, results of the analysis conducted for each item which are publicity and measures the ease. 'Facilities', 'landscape and greenery', 'pedestrian road' and others were commonly appears from residents and professional awareness of the complaints. However, complaints of park appear different awareness between landscape architecture and residents. Fourth, 35 from 73 civil complaints(47.9%) are having high publicity and easy to measure, 25 civil complaints(34.2%) has analyzed to individual and difficult to measure so about the these complaints need to check from the design step so that it is necessary to minimize the problem of additional expense by civil complaints burden and decrease the confidence of residence problem were considered.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.1
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• pp.68-77
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• 2022

The human thermal environment in an apartment complex located in Seoul was quantitatively analyzed to devise methods to modify human heat-related stresses in landscape and urban planning. Microclimatic data (air temperature, relative humidity, wind speed, and short- and long-wave radiation) were collected at 6 locations [Apt-center, roof (cement), roof (grass), ground, playground, and a tree-lined road] in the late spring and summer, and the data were used to estimate the human thermal sensation, physiological equivalent temperature (PET) and universal thermal climate index (UTCI). As a result, the playground location had the highest thermal environment, and the roof (grass) location had the lowest. The mean difference between the two locations was 0.8-1.1℃ in air temperature, 1.8-4.0% in relative humidity, and 7.5-8.0℃ in mean radiant temperature. In open space locations, the wind speed was 0.4-0.5 ms-1 higher than others. Also, a wind tunnel effect happened at the Apt-center location during the afternoon. For the human thermal sensation, PET and UTCI, the mean differences between the playground and roof (grass) locations were: 5.2℃ (Max. 11.7℃) in late spring and 5.4℃ (Max. 18.1℃) in summer in PET; and 3.0℃ (Max. 6.1℃) in late spring and 2.6℃ (Max. 9.8℃) in summer in UTCI. The mean differences indicated a level change in PET and 1/2 level in UTCI, and the maximum differences showed greater changes, 2-3 levels in PET, and 1-1.5 levels in UTCI. Moreover, the roof (grass) location gave 4.6℃ PET reduction and a 2.5℃ UTCI reduction in late spring, and a 4.4℃ PET reduction and a 2.0℃ UTCI reduction in the summer when compared with the roof (cement) location, which results in a 2/3 level change in PET and a 1/3 level in UTCI. Green infrastructure locations [roof (grass), ground, and a tree-lined road] were not statistically significant in the reduction of PET and UTCI in thermal environment modifying effects. The implementation of green infrastructure, such as rooftop gardens, grass pavement, and street tree planting, should be adopted in landscape planning and be employed for human thermal environment modification.

• Journal of Practical Agriculture & Fisheries Research
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• v.4 no.1
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• pp.128-137
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• 2002

This study was conducted to develop the heat exchanger by utilizing the heat energy of underground water(15℃), which might be used for cooling and heating system of the agricultural facilities. We developed the heat exchanger by using the parallel type plat fin tube made of Aluminum(Al 6063), which was named Aloo-Heat(No. 0247164, offered by Korean Intellectual property Office). The trial manufactures were made from Aloo-heat which was 600mm, 700mm length respectively, and It were welded to the end "U" type in order to direct flow of the underground water. The performance test was carried out under the condition of open space and room temperature with the change of flow rate of the underground water and air. The results are as follows. 1. The trial manufactures had convection heat value from 33 to 156 W/m²℃, and It was coincided with design assumption. 2. The amount of energy transfer was increased with the increment of the area of heat transfer, the air flow, the gap of temperature inlet & outlet the underground water and the air. 3. The heat value was 6,825W when the air flow was 6,000m³/h and the gap of temperature between inlet and outlet of the underground water was 6℃, and It dropped from 25.8℃ to 23.2℃(-2.6℃ difference). The convection heat value was 88.5W/m²℃. 4. The heat value was 2.625W when the air flow was 4,000m³/h and the gap of temperature between inlet and outlet the underground water was 2℃, and It dropped from 27℃ to 22.5℃(-4.5℃ difference). The convection heat value was 33.6W/m²℃. 5. Correlation values(R²) of the testing heat values of the trial manufacture type I, II, and III were 0.9141, 0.8935, and 0.9323 respectively, and correlation values(R²) of the amount of the air flow 6,000m³/h, 5,000m³/h, 4,000m³/h were 0.9513, 0.9414, and 0.9003 respectively.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.543-553
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• 2023

The current status of domestic a agalmatolite mines in South Korea was investigated with a view to establishing a stable supply of agalmatolite and managing its demand. Most mined agalmatolite deposits were formed through hydrothermal alteration of Mesozoic volcanic rocks. The physical characteristics of pyrophyllite, the main constituent mineral of agalmatolite, are as follows: specific gravity 2.65~2.90, hardness 1~2, density 1.60~1.80 g/cm³, refractoriness ≥29, and color white, gray, grayish white, grayish green, yellow, or yellowish green. Among the chemical components of domestic agalmatolite, SiO₂ and Al₂O₃ contents are respectively 58.2~67.2 and 23.1~28.8 wt.% for pyrophyllite, 49.2~72.6 and 16.5~31.0 wt.% for pyrophyllite + dickite, 45.1 and 23.3 wt.% for pyrophyllite + illite, 43.1~82.3 and 11.4~35.8 wt.% for illite, and 37.6~69.0 and 19.6~35.3 wt.% for dickite. Domestic agalmatolite mines are concentrated mainly in the southwest and southeast of the Korean Peninsula, with some occurring in the northeast. Twenty-one mines currently produce agalmatolite in South Korea, with reserves in the order of Jeonnam (45.6%) > Chungbuk (30.8%) > Gyeongnam (13.0%) > Gangwon (4.8%), and Gyeongbuk (4.8%). The top 10 agalmatolite-producing mines are in the order of the Central Resources Mine (37.9%) > Wando Mine (25.6%) > Naju Ceramic Mine (13.4%) > Cheongseok-Sajiwon Mine (5.4%) > Gyeongju Mine (5.0%) > Baekam Mine (5.0%) > Minkyung-Nohwado Mine (3.3%) > Bugok Mine (2.3%) > Jinhae Pylphin Mine (2.2%) > Bohae Mine. Agalmatolite has low thermal conductivity, thermal expansion, thermal deformation, and expansion coefficients, low bulk density, high heat and corrosion resistance, and high sterilization and insecticidal efficiency. Accordingly, it is used in fields such as refractory, ceramic, cement additive, sterilization, and insecticide manufacturing and in filling materials. Its scope of use is expanding to high-tech industries, such as water treatment ceramic membranes, diesel exhaust gas-reduction ceramic filters, glass fibers, and LCD panels.