• Journal of Korean Society on Water Environment
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• v.36 no.5
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• pp.392-404
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• 2020

The focus of this study was to quantify the thermal stratification and analyze the relationship between the stratification structure and the tributaries to understand flow variations in the Paldang Reservoir. The vertical distribution of the temperature and density gradients, and the depth and thickness of the thermocline were quantitatively calculated using a lake physics tool (rLakeAnalyzer) and high-frequency monitoring data. Based on a density gradient of 0.2 kg/㎥/m, the thermocline was formed from mid-May to early-September 2019 and the other periods were weakly stratified or mixed. The thickness of the thermocline was developed until 4.7 m and the depth of the thermocline was formed at a depth of 3 - 6 m at the front of the Paldang Reservoir. During the formation of the thermocline, the Namhangang and Gyeongancheon tributaries with relatively high water temperature (low-density) flowed into the upper layer of the reservoir, and the Bukhangang tributary with low water temperature (high-density) mainly affected the lower layer of the reservoir. This is because the density currents were formed due to the difference in the water temperature of the tributaries. The findings of this study may be used for constructing high-frequency monitoring and quantitative data analyses of reservoirs.

• Ocean and Polar Research
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• v.27 no.1
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• pp.1-13
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• 2005

The samples for organic carbon analysis were collected between $5^{\circ}\;and\;17^{\circ}N$ along $131.5^{\circ}W$ in the northeast Pacific KODOS (Korea Deep Ocean Study) area. The mean concentration of total organic carbon (TOC) in the surface mixed layer $({\sim}50 m)$ was $100.13{\pm}2.05{\mu}M-C$, while the mean concentration of TOC in the lower 500m of the water column was $50.19{\pm}4.23{\mu}M-C$. A strong linear regression between TOC and temperature $(r^2=0.70)$ showed that TOC distribution was controlled by physical process. Results from the linear regression between chlorophyll-a and TOC, and between chlorophyll-a and particulate organic carbon (POC), decreasing of dissolved organic carbon (DOC) in the surface layer caused by non-biological photo-oxidation process. Below the surface layer, biological production and consumption occurred. DOC accumulation dominated in the depth range of $30{\sim}50m$ and DOC consumption occurred in the depth range of $50{\sim}200m$. TOC was inversely correlated with apparent oxygen utilization (AOU) and TOC/AOU molar ratios ranged from -0.077 to -0.21. These ratios indicated that TOC oxidation was responsible fur $10.9{\sim}30.1%$ (mean 20.2%) of oxygen consumption in the NE Pacific KODOS area. In the euphotic zone, distributions of dissolved and particulate organic matter were controlled by photo-chemical, chemical, biological and physical processes.

• Korean Journal of Environmental Biology
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• v.24 no.1 s.61
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• pp.67-80
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• 2006

The effect of environmental forcing on picophytoplankton distribution pattern was investigated in the tropical and subtropical western Pacific (TSWP) and the East Sea in September, 2002, and the continental shelf of the East China Sea (C-ECS) in August, 2003. The abundance of picophytoplankton populations, Synechococcus, Prochlorococcus and picoeukaryotes were determined by flow cytometry analyses. Picophytoplankton vertical profiles and integrated abundance $(0\sim100\;m)$ were compared with these three physiochemically different regions. Variation patterns of integrated cell abundance of Synechococcus and Prochlorococcus in these three regions showed contrasting results. Synechococcus showed average abundance of $84.5X10^{10}\;cells\;m^{-2}$, in the TSWP, $305.6X10^{10}\;cells\;m^{-2}$ in the C-ECS, and $125.4X10^{10}\;cells\; m^{-2}$ in the East Sea where increasing cell concentrations were observed in the region with abundant nutrient. On the other hand, Prochlorococcus showed average abundance of $504.5X10^{10}\;cells\;m^{-2}$ in the TSWP, $33.2x10^{10}\;cells\;m^{-2}$ in the C-ECS, and $130.2X10^{10}\;cells\;m^{-2}$ in the East Sea exhibiting a distinctive pattern of increasing cell abundance in oligotrophic warm water. Although picoeukaryotes showed a similar pattern to Synechococcus, the abundance was 1/10 of Synechococcus. Synechococcus and picoeukaryotes showed ubiquitous distribution whereas Prochlorococcus generally did not appear in the C-ECS and the East Sea with low salinity environment. The average depth profiles for Synechococcus and Prochlorococcus displayed uniform abundance in the surface mixed layer with a rapid decrease below the surface mixed layer. for Prochlorococcus, a similar rapid decreasing trend was not observed below the surface mixed layer of the TSWP, but Prochlorococcus continued to show high cell abundance even down to 100 m depth. Picoeukaryotes showed uniform abundance along $0\sim100\;m$ depth in the C-ECS, and abundance maximum layer appeared in the East Sea at $20\sim30\;m$ depth.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.332-344
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• 1996

The vertical profiles of the natural $^{210}Po,\;^{210}Pb\;and\;^{234}Th$, activities were measured at the upper 150 m or 200 m of water column from west-east intersection in the east-southern coastal area of the Korea Peninsula during the period from 26 to 29 April 1994 to compare the removal rates (residence time) and removal processes for $^{210}Po\;and\;^{234}Th$. At the inshore stations, the $^{210}Po$ activity was generally higher in the thermocline and its under layer than in the surface mixed layer, while represented the reversed pattern at the offshore stations. However, the $^{210}Pb$ activity decreased generally with depth. Also, the activity of $^{210}Po$ relative to its parent $^{210}Pb$ was deficient in the water column above the main thermocline, but was slightly excess or close to equilibrium in the thermocline and its under layer. The vertical profiles for the activity of $^{210}Pb$ relative to its parent $^{226}Ra$ showed the reversed pattern with the vertical variation of $^{210}Po$ excess (or deficiency). The $^{234}Th$ activity was significantly lower in the surface mixed layer and thermocline than in the deeper layer. The residence time of $^{210}Po$ ranged from 1 to 4 years at the five stations except station E8 that showed yet long residence time (approximately 10 years). The long residence time at the station E8 may resulted from the thicker surface mixed layer and subsequent the vertical mixing of $^{210}Po$ which was recycled in the lower surface mixed layer compared to at the other stations. Also, the residence time of $^{210}Po$ was shorter at the inshore stations than at the offshore stations. However, the residence time of $^{234}Th$ ranged from 52 to 74 days at all station without the significant variation, was very much shorter relative to the residence time of $^{210}Po$. The correlation between the removal rate of dissolved $^{234}Th$ and the concentration of total suspended matter (TSM) was generally positive. Therefore, it seems that the major route of the removal mechanism of $^{234}Th$ from seawater in the surface mixed layer is via adsorption onto suspended particle surfaces (most likely inorganic particles) and subsequent settling to the bottom layer. Between the removal rate of dissolved $^{210}Po$ and the concentration of chlorophyll-a was positively good correlation. Consequently, most likely the removal of $^{210}Po$ may be occurred by uptake to organisms (mainly such as planktonic debris or fecal pellets) and subsequent settling.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.3
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• pp.151-162
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• 2013

Studies of the distribution of micro-phytoplankton community and chlorophyll a concentration have focused on the vertical profiles of marine environmental factors such as water temperature, salinity, sigma-t, light intensity, and dissolved oxygen in the continental slope on the east parts of East China Sea in the early summer of 2009. Water temperature showed a gradual reduction according to the depth. While the salinity was low in the surface layer showing a mixed down to the relatively subsurface layer, it was increased with an increase in the depth at the middle and bottom layers showing a maximum value at 150~200 m followed by a decreasing aspect afterwards, although the change was not large. The change of sigma-t was governed by the water temperature, and gradually increased in the surface layer with an increase in the depth, showing a value higher than in the surface layer by about 3 $kg/m^3$ at the bottom layer. Although the intensity of light was exponential reduced in the surface layer, the compensation depth was located at the depth of about 80m. The vertical profiles of chlorophyll a concentration was governed by the intensity rather than the changes in water temperature or salinity, exhibiting a maximum value at the compensation depth corresponding to 1% in the surface light intensity. The micro-phytoplankton communities consisted of 56 genera 103 species showing a relatively variety, while the standing crop was also changed to 112.0~470.0 cells/L in the pelagic environment, showing a maximum chlorophyll a concentration. Although a variety of dominant species appear at low dominance without dominant species appearing with a right-wing point in the phytoplankton communities, the silicoflagellate, Otactis otonaris at the station A and the dominance of 26% due to Leptocylindrus mediterraneus at the station C have been judged to be unusual. For community analysis of infinitesimal creatures such as phytoplankton of oligotrophic waters through the present study, ecology studies through vertical sample collection agreeing with the results of continuous observation such as identification of vertical distribution in a marine environment or of maximum chlorophyll layers have been considered rather than a survey method with intervals of a given depth such as surface, subsurface, middle and bottom layers.

• Journal of the Korean GEO-environmental Society
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• v.7 no.1
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• pp.29-39
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• 2006

Recently, Korea brings to remarkable levels about industrialization, modernization, population and development of technology. Especially, the rapidly growing from this technology has increased the burden on existing industrial waste landfills. The purpose of this research is to existing knowledge base of landfill cover liner behavior during periods freeze/thaw. Although these tests have been invaluable in clarifying the problem of freeze/thaw, extending the results of such experimental studies to prototype landfills are questionable. For this investigation, the author utilized a large scale laboratory simulation allowing inclusion of the field depth of the cover systems, layered soil profiles, rainfall simulation, a cold climate and boundary conditions similar to those encountered in the landfill. And the soil materials used stabilized soils (mixed clays, cements, and minerals) instead of clays. The bottom liners are made up of drainage layer (30cm), stabilized layer (75cm), and leach collection layer (60cm). The stabilized layers are made up of supporting layer (45cm) and impermeable layer (30cm) - consisted of $P_A$ and $P_B$ layer.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.683-691
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• 2001

This study aimed to clarify the influencing factors of the mesopore ratio on a pore geometry of surface soil in mixed stands as an index of the water retention capacity. Twenty four factors including site conditions and soil properties were analyzed by spss/pc+ for the data collected from during March to October of 1995. The factors influencing the mesopore ratio(pF2.7) on the surface soil were as follows; mesopore ratio(pF2.7) on the B horizon soil, under vegetation coverage, organic matter contents of surface soil and F layer depth. And influencing factor on the ratio of mesopore in the soil surface was correlated with surface soil hardness and depth of 10cm soil hardness shows high negative significance. Also, multiple regression equations for mesopore ratio of the mesopore ratio of B horizon soil and organic matter contents shows high significance($R^2$; 0.84).

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.273-273
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• 2022

혼합층(Mixed layer)은 온도가 일정한 수심층으로, 해수표면에 작용하는 바람의 영향으로 인하여 해수가 위아래로 섞여 형성된다. 이러한 혼합층은 영양염의 순환과 산소의 공급 등과 함께 일차생산량을 결정하는 중요한 요인이 될 수 있으며 혼합층 두께의 변동은 양식 산업에 영향을 미칠 수 있다. 최근에는 기후변화로 인한 해수면 상승 및 해수온 상승 등이 지속되고 있으며, 이러한 현상은 해양생태계의 변화를 초래하여 수산업의 피해를 유발할 수 있다(강원연구원, 2017). 이에 국립수산과학원, 기상청, 국립해양조사원 등 유관기관에서는 정선해양 수온 관측 및 해수순환모델을 이용하여 혼합층의 분석을 수행하고 있으나 격자 구축 및 초기·경계장 설정의 한계가 존재하여 정밀하고 정확한 혼합층 분석에는 어려움이 있다. 이에 본 연구에서는 비정형격자를 사용하여 격자 구축에 제약이 없는 SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model)을 이용하여 우리나라 연안해역의 계절변화 및 기후변동성에 따른 혼합층 두께의 변화를 검토하고자 한다. 연구대상지는 서해·동해·남해를 포함한 우리나라 전체 연안 해역(위도: 32°N ~ 39°N, 경도: 124°E ~ 132°E)으로 선정하였으며, 격자크기 100 ~ 3,000 m인 삼각격자로 격자를 구축하였다. 혼합층을 분석하기 위하여 수직격자 층은 50층으로 SZ(Sigma Z coordinate system)좌표계를 사용하였다. 초기·경계장은 FES(Finite Element Solution)2014, HYCOM(Hybrid Coordinate Ocean Model) 및 대기모델 결과를 이용하여 설정하였다. 수치모형 검증을 위하여 수온관측소에서 수심별 측정한 수온 값과 SCHISM 결과 값을 비교하였고, 상대오차가 약 10% 이내로 나타나 모형의 정확도를 확인하였다. 최종적으로 해수면 상승 및 해수온 상승 시나리오를 고려하여 계절별 연안해역의 혼합층 두께의 변화 양상에 대하여 검토하였다. 향후에는 보다 정밀한 대기모델과의 혼합모형 구축 및 다양한 수심 별 관측자료를 활용한다면 실무에서 적용 가능한 혼합층 분석 및 수산업 피해 발생 지역에 대한 피해저감 대책 수립이 가능할 것으로 판단된다.

• Journal of the Korean Institute of Landscape Architecture
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• v.15 no.2
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• pp.67-78
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• 1987

This study was executed to measure the user\`s impact natural environment in National Park Campsite. Therefore, we choose Mt. Chiak National Park and the campsite in the district of Temple Ku-Ryong as a model of analysis, which is made by ecological approach, the number of the user has influence on the environment near the campsite. The result are as follows : 1. The more the number of users becomes, the more Na, Ca, Mg ion concentration and pH in the soil increase and the less K ion becomes. 2. Litter and humus depth, litter coverage, herb coverage, soil hardness, the surface of the ground layer and tree species numbers, density and coverage of lower layer shows a sensitive reaction to the number of the users. 3. The research shows that the tolerant trees against campsite impact are Lespedeza maximowiczii, Zanthoxylum schinifolium Staphylea bumalda, Smilax sieboldii, Quercus aliena, Euonymus oxyphyllus, Weigela subsessilis and Securinega suffruticosa, and the sensitive trees are Stephanandra incisa, Rubus trichocarpa, Rubus crataegifolius, Rhododendron mucronulatum, Styrax obassia, Acer palmatum, Lindera obtusiloba, Rhododendron suhlippenbachii, Rhus japonica and Callicarpa japonica. 4. The high density of the users made the simplication of a vegetation structure. So, as the number of the user increase the species showed severe heterogeniety between the heavy-use and nonuse site. 5. As considering the landscape management about campsite and surrounding area on the way of analysis of national landscape aspect and succession sere according to ecological aspect, it may be desirable that Pinus densiflora forest be conserved as Pinus densiflora landscape and mixed forest produce natural scenery with succession sere.

• Journal of the Korean Society of Clothing and Textiles
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• v.46 no.4
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• pp.624-637
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• 2022

The purpose of this study was to develop a compression inner layer (CIL) that can be attached to dress shirts for men who have gynecomastia (male breast enlargement). For this, we developed shirts with CIL prototypes based on the functional, expressive, and aesthetic (FEA) consumer needs model. The user-centered design principle guided the design process. Based on size measurements, in-depth interviews, and an online survey, the design requirements for dress shirts with a CIL were determined, and the prototype was developed. The dress shirts were constructed of polyester and spandex mixed materials, while the CIL was made of thin mesh fabric knitted from 80% polyester and 20% spandex. A CIL prototype was developed with a front zipper fastening to hold the upper body tight and compress the breast area. The CIL was attached by connecting a strap with snap buttons to loops sewn into the shoulder line of the dress shirt. In the trial and sensory test, the prototype helped breast size decrease while meeting target consumer needs. The outcomes of this study provide necessary insights to develop garments for gynecomastia patients.