• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.700-707
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• 2003

Surface sediments in the mouth area of Jinhae Bay were investigated to evaluate the benthic environment in terms of geochemical criteria and macrobenthos abundance. Characteristics of the surface sediment distribution exhibited muddy sediments in the most part of study area. Some mixed sediments of coarse sand and mud were distributed along the coastal area of Geoje Island and around the Jeo Islands. Organic matter from ignition loss and total organic carbon from CHNS varied between $8.8-1.7\%,\;and\;4.62-0.77\%,$ respectively. The source of organic matter based on the C/S ratio was mixed with in situ biogenic and terrigenous organic matter. The C/S ratio of organic matter also suggested both an anoxic bottom condition in several parts of the study area. The content of hydrogen sulfide in surface sediment was extremely variable and showed spatio-temporal variation from site to site. In several locations, the content of hydrogen sulfide as an index of eutrophication was over the critical value (0.2 mg/g), suggesting that several parts of the study area were not favorable for the habitat of macrobenthos. The relationship among the number of individuals of marcrobenthos, hydrogen sulfide, and organic matter was not clear, but a potential negative relationship between individuals of marcrobenthos and hydrogen sulfide was indicated.

• Journal of the Korean association of regional geographers
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• v.20 no.3
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• pp.334-343
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• 2014

The number of malaria cases has been undulating for the past 10 years in Korea since the reemergence of malaria in early 1990's. Considering the spatial variations of malaria incidence across the northmost border areas near the demilitarized zone (DMZ), the occurrence of the disease seems to be influenced by the natural and human environment in the region. Malaria is an infectious disease that is transmitted to humans by the bites of vector-mosquitoes that carry malaria parasites, and its incidence rate depends on specific climatic and sociodemographic factors. This study found that the spatial characteristics of malaria incidence have varied depending on relative proportions of mosquito habitats, distance between mosquito habitats and human residence, the physical and sociodemographic environments of the city by urbanization, and local topography.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.24 no.5
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• pp.319-325
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• 2012

A new formulae for the estimation of the exposure duration in the inter-tidal zone are developed. The exposure duration is one of the most important factors influencing the habitat distribution of the benthic organisms. The formulae can estimate the exposure duration only using the four major tidal harmonic constants available in almost coastal areas. It is easier than the existing method using the frequency analysis of the hourly tidal elevation data. The estimation results by using the formulae suggested in this study are compared with the value by using the observed tidal elevation data analysis in the west coast, Korea. The mean RMS (root-mean squared) errors ranged form 0.8 to 1.4%. It can be used to simply estimate the accurate exposure duration in the region not having the longterm hourly tidal elevation data.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.41-46
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• 2018

The context of innovation in which we evolve today, subtracts us in a spacial reality and virtuality (digital) that aimed less and less to interact with natural processes which could converge to new possible relationships in the world. We constantly live in presence of fluctuations and imperceptible natural energies (wind, solar radiation, etc.) defined by flows, their own physicality, which remains without being virtual, elusive. This study first outlines how these energies already exploited within the framework of production, could be thought as interactive of our habitat's space dimension, as a prolongation of a physical and material environment built by men and for men, giving rise to new social, cultural dynamics, and making natural complexity of our space vivid, comprehensible with new visual and physical clues. In recent days, where lifestyles are changing, architecture no longer needs to limit its scope of creation to only built structures. Based on a deeper understanding of human and through new potential advanced technologies (kinetic system, etc), it is time to fundamentally diagnose what environments or devices contribute to our lives. Architecture becomes ${\ll}interface{\gg}$, step up its fundamental role, and newly defines the sturdy image and tectonics of existing environment, establishing a stance to search for a new typology. In the end, building will show two simultaneous and distinctive connections related to its physical existence: reality in its function and irreductibility, in its ability to forge new dynamic connections with its environment, hybridizing the spatial dimension to a new form of physicality, adaptive and incessantly flexible in the dimension time, becoming a vessel for ever changing contemporary lifestyles.

• Korean Journal of Ornithology
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• v.25 no.2
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• pp.106-111
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• 2018

The Black-tailed gull (Larus crassirostris) is one of the most common gull species in the Northeast Asia and classified as LC (least concern) in the IUCN Red List. The bird has become a useful indicator for marine environmental pollution and habitat disruption, since the human activities impacted marine environments. Here we show that the black-tailed Gull has 6 haplotypes and some rare haplotypes are locally limited implying that the bird may not disperse far. This study may be the first report on population genetic study of Black-tailed Gull in Korea and could be used as the baseline data for monitoring and genetic study on the bird as an environmental indicator.

• Journal of Ecology and Environment
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• v.46 no.4
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• pp.304-315
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• 2022

Background: Filter-feeding zooplankton has limited food resources owing to their habitat. Consequently, it is crucial for them to acquire all essential compounds, such as fatty acids (FAs) and amino acids, from confined diets. To elucidate the trophic transfer of FAs to filter feeders, the primary consumers in freshwater ecosystems, we compared the FA accumulation patterns of two species of filter-feeding zooplankton, Daphnia magna and Branchinella kugenumaensis, in a laboratory experiment. Experimental neonates and nauplii preyed on a single phytoplankton species (Selenastrum capricornutum) for three days after hatching prior to diet switching. Five replicates per feeding group in each species were fed on six different types of mixed phytoplankton diet for 10 days after diet switching. Subsequently, the consumers and diets were harvested and FAs were extracted. Results: Principal component analysis showed that the FA profiles of zooplankton were well-grouped by species and diet. Although diet affects the FA profiles of consumers, they exhibit different FA accumulation patterns. D. magna had a higher 18C-ω3 content and ω3/ω6 ratio than did B. kugenumaensis. In contrast, B. kugenumaensis had higher contents of 18:1ω7 and 20:5ω3 (eicosapentaenoic acid), 22:6ω3 (docosahexaenoic acid), and a higher ratio of ∑18C monounsaturated FAs to ∑18C-ω3 polyunsaturated FAs than did D. magna. Conclusions: This study showed that two primary consumers, D. magna and B. kugenumaensis, fed the same diet had different assimilation patterns of FAs under controlled environments. Specific FA accumulation patterns in filter feeders can provide information on the transfer process of various FAs to high-trophic organisms.

• International Journal of High-Rise Buildings
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• v.12 no.2
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• pp.129-136
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• 2023

Natural ventilation has proven to be an effective passive strategy in improving energy efficiency and providing healthy environments. However, such a strategy has not been commonly adopted to tall office buildings that traditionally rely on single-skin façades (SSFs), due to the high wind pressure that creates excessive air velocities and occupant discomfort at upper floors. Double-skin façades (DSFs) can provide an opportunity to facilitate natural ventilation in tall office buildings, as the fundamental components such as the additional skin and openings create a buffer to regulate the direct impact of wind pressure and the airflow around the buildings. This study investigates the impact of modified multi-story type DSFs on indoor airflow in a 60-story, 780-foot (238 m) naturally ventilated tall office building under isothermal conditions. Thus, the performance of wind effect related components was assessed based on the criteria (e.g., air velocity and airflow distribution), particularly with respect to opening size. Computational fluid dynamics (CFD) was utilized to simulate outdoor airflow around the tall office building, and indoor airflow at multiple heights in case of various DSF opening configurations. The simulation results indicate that the outer skin opening is the more influential parameter than the inner skin opening on the indoor airflow behavior. On the other hand, the variations of inner skin opening size help improve the indoor airflow with respect to the desired air velocity and airflow distribution. Despite some vortexes observed in the indoor spaces, cross ventilation can occur as positive pressure on the windward side and negative pressure on the other sides generate productive pressure differential. The results also demonstrate that DSFs with smaller openings suitably reduce not only the impact of wind pressure, but also the concentration of high air velocity near the windows on the windward side, compared to SSFs. Further insight on indoor airflow behaviors depending on DSF opening configurations leads to a better understanding of the DSF design strategies for effective natural ventilation in tall office buildings.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.89-90
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• 2021

Undersea bases built in the deep sea are built in more extreme environments than in space. In addition, it requires the convergence of mechanics, electronics, shipbuilding, meteorology, and diving science, marine physics, chemistry, biology, and geology. Undersea base can be constructed through the fusion of various technologies. The development of extreme technology for undersea construction will be the most advanced technology in each field, and it will be applied to space and other fields, so it will be an opportunity to preempt the latest technology.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.109-121
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• 2023

Squr dikes in rivers can enhance various ecological environments, contributing to the improvement of the river's environmental functions. However, the alterations in flow caused by squr dikes not only enhance environmental functions but can also have adverse effects. Therefore, this study aimed to analyze the flow changes induced by the installation of squr dikes through flume experiments and assess their impact on fish habitats. Key factors in the fish habitat environment include flow velocity, turbulence kinetic energy, and recirculation zones. Among these, particular emphasis was placed on examining turbulence kinetic energy and recirculation zones. Experimental conditions were set by varying the interval and submergence of the squr dikes, resulting in a total of eight experimental cases. The results revealed that shorter interval and lower submergence of the squr dikes led to increased turbulence kinetic energy and recirculation zone sizes, significantly impacting fish habitats.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.225-238
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• 1997

Zooplankton distribution in the front zone was investigated in the East Sea of Korea (Sea of Japan). More than 100 taxa appeared in the study area, which was far diverse appearance being compared with those in West (Yellow Sea) and South Sea of Korea. In Nov. 1994, Paracalanus parvus, Oikopleura spp., and Noctiluca scintillans, which preferred warmer environment, predominated at the collection sites in the front zone, especially at warmer surface layer. But in Nov. 1995, when the surface water temperatures were about $2^{\circ}C$ lower than those of the previous year, cold water species of copepod Metridia lucens, immature forms of Calanus and Sagitta, and crustacean eggs dominated in the collection sites in front zone, which were geographically not Identical with those of the previous year. Vertical distributional patterns were not coincide among the taxa. This suggests that zooplankton has different specific habitat characteristics with temperatures. In general, those taxa with preference of warmer environments showed high probability of co-occurrance with low abundances while those that preferring colder environments showed low probability of co-occurrance with high abundances. It seems that warm water contributes to the high diversity of zooplankton in the front zone while cold water does to the high biomass.