• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.2
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• pp.81-96
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• 2011

Sediment oxygen demand(SOD) and denitrification rates were measured in four major estuaries(Suncheon Bay, Seomjin river estuary, Goseong stream estuary and Masan Bay) in south coast of Korean peninsula from March of 2009 to May 2010 to estimate organic matter cleaning capacity. SOD was estimated from the temporal dissolved oxygen concentration change and isotopic pairing technique was employed to measure denitrification. Sediment oxygen demand(SOD) was ranged from -5.1 to 24.6 mmole $O_2m^{-2}d^{-1}$ and denitrification rate was ranged from 0.0 to 3.9 mmole $N_2m^{-2}d^{-1}$in the study area. SOD was the highest in Masan Bay(-2.2 to 19.2, average = 10.2 mmole $O_2m^{-2}d^{-1}$) and Suncheon, Goseong, Tae-an and Seomjin followed. Denitrification was also the highest in Masn Bay(0.0 to 3.9, average = 1.0 mmole $N_2m^{-2}d^{-1}$) and Goseong, Seomjin, Suncheon and Taean followed. The effect of benthic photosynthesis by microphytobenthos on denitrification was evident in some season of Tae-an, Seomjin, and Masn Bay. The increased oxygen level produced by photosynthesis stimulated nitrification without severe adverse effect on denitrification and, as a result, coupled nitrification and denitrification was enhanced in these areas. A difference of seasonal patterns of denitrification at each site depended on relative importance of denitrification on different nitrate source($D_w$: nitrate from water column and $D_n$: nitrated produced during nitrification). Denitrification was maximum during spring in Goseong, Suncheon and Masan Bay. On the contrary, denitrification was the highest during summer in Tae-an and Seomjin estuary.

• Korean Journal of Remote Sensing
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• v.29 no.4
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• pp.375-387
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• 2013

Accuracy assessment of tide models in polar ocean has to be performed to accurately analyze tidal response of glaciers by using Double-Differential Interferometric SAR (DDInSAR) technique. In this study, we used 120 DDInSAR images generated from 16 one-day tandem COSMO-SkyMed DInSAR pairs obtained for 2 years and in situ tide height for 11 days measured by a pressure type wave recorder to assess the accuracy of tide models such as TPXO7.1, FES2004, CATS2008a and Ross_Inv in Terra Nova Bay, East Antarctica. Firstly, we compared the double-differential tide height (${\Delta}\dot{T}$) for Campbell Glacier Tongue extracted from the DDInSAR images with that predicted by the tide models. Tide height (T) from in situ measurement was compared to that of the tide models. We also compared 24-hours difference of tide height ($\dot{T}$) from in situ tide height with that from the tide models. The root mean square error (RMSE) of ${\Delta}\dot{T}$, T and $\dot{T}$ decreased after the inverse barometer effect (IBE)-correction of the tide models, from which we confirmed that the IBE of tide models should be corrected requisitely. The RMSE of $\dot{T}$ and ${\Delta}\dot{T}$ were smaller than that of T. This was because $\dot{T}$ is the difference of tide height during temporal baseline of the DInSAR pairs (24 hours), in which the errors from mean sea level of the tide models and in situ tide, and the tide constituents of $S_2$, $K_2$, $K_1$ and $P_1$ used in the tide models were canceled. This confirmed that $\dot{T}$ and ${\Delta}\dot{T}$ predicted by the IBE-corrected tide models can be used in DDInSAR technique. It was difficult to select an optimum tide model for DDInSAR in Terra Nova Bay by using in situ tide height measured in a short period. However, we could confirm that Ross_Inv is the optimum tide model as it showed the smallest RMSE of 4.1 cm by accuracy assessment using the DDInSAR images.

• Journal of Aquaculture
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• v.5 no.1
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• pp.93-108
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• 1992

This study was conducted to understand the variation of suspended matters in coastal waters of Cheju Island. Water sampling was carried out at 22 stations along the coast of this island from March 1988 to November 1989. Analyzed and/or observed items were water temperature, salinity, total solids (TS), total dissolved solids (TDS), volatile suspended solids (VSS), and fixed suspended solids (FSS). Inter-relationships between wind velocity, precipitation and total suspended solids (TSS) were also investigated. More windy days prevail in winter season (December, January and February) in Cheju Island. Thirty-six points seven percent of total windy days of a year appeared in this season. The rate of windy days in spring was $27.3\%$ and those in summer and fall were $17.9{\%}$ each. From February to July, the heaviest precipitation was observed in the southeastern area and that from August to January was observed in the eastern part of this island. TS and TDS were firmly related with the fluctuation of salinity. Therefore, there were higher in spring and lower in summer. The highest TSS (7.73 $mg/{\ell}$) was observed in February and was the lowest (4.73 $mg/{\ell}$) in September. Annual mean value of TSS was 6.3$mg/{\ell}$. The highest VSS (2.03 $mg/{\ell}$) was observed in July and lowest (1.42 $mg/{\ell}$) in September. The percentage of VSS per 755 was $30.6{\%}$ in average that was not much higher level compared to the other polluted areas. This value became higher in summer (av. $34.17{\%}$) and lower in winter (av. $24.2{\%}$). Fluctuation of TSS was mainly related with the freshwate. discharge, tidal action, and re-suspension of bottom sediments by the wind waves. Therefore, TSS concentration was low in summer and hish in winter.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.129-136
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• 1970

As an attempt to determine if the morphological differences between the southern and western oysters are due simply to the local ecological factors or are based on their fundamental genetic nature, oyster seeds produced in 1968 at Tong-Young, Ye-Chun, and Ko-Hung on the south coast and at Kan-Wol-Do on the west coast were cross-transplanted during May of 1969 to compare their growth. The spats were placed in plastic baskets which permitted free water flow through and the baskets hung from a wooden rack located at a tidal zone of less than I hour exposure at a depth chosen to keep the baskets submerged in water at all times. Twice a month the growth of the spats were measured along with the air and water temperature and salinity. The early summer spats, which were $17-240\%$ larger, in size, than the late summer spats at the time of cross-transplantation, grew more slowly than the late summer spats when exposed to identical environmental conditions, shortening the initial gap to a $5-20\%$ level as the first year of the growth phase came to an end in December. The growth of the Kan-Wol-Do spats lagged considerably behind the southern spats at all localities tested, whereas there were no significant differences among the latter groups. This suggests that the morphological differences between southern and western Pacific oysters in Korea are a manifestation of genetic variety and that Pacific oysters cultured along the south coast are of an identical variety as they are commonly believed to be. The seasonal changes in temperature and salinity even during rainy season in both the southern and western coastal areas are well within the range suitable for successful spawning, and spat fall. However, since the results were based on twice-a-month measurements with no data covering the critical period before and after spawning, they can only serve to indicate at best the general pattern of changes in the environmental conditions of each growing area.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.727-743
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• 1996

To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

• Journal of Wetlands Research
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• v.6 no.3
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• pp.55-70
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• 2004

The wetland ecosystem is a complex products of various erosion force, accumulation as water flows, hydrogeomorphic units, seasonal changes, the amount of rainfalls, and other essential element. There is no single, correct, ecologically sound definition for wetlands because of the diversity of wetlands and the demarcation between dry and wet environments occurs along a continuum, but wetland plays various ecosystem functions. Despite comprehensive integration through classification and impact factors there is still lacking in systematic management of wetlands. Classification system developed by the USFWS(1979) is hierarchical progresses from systems and subsystems at general levels to classes, subclasses, dominance types, and habitat modifiers. Systems and subsystems are delineated according to major physical attributes such as tidal flushing, ocean-derived salts, and the energy of flowing water or waves. Classes and subclasses describe the type of substrate and habitat or the physiognomy of the vegetation or faunal assemblage. Wetland classes are divided into physical types and biotic types. For the wise management of wetlands in Korea, this study was carried out to examine methodology of USFWS classification system and discuss its application for Korean wetland hydrogeomorphic units already known. Seven wetland types were chosen as study sites in Korea divided into some different types based on USFWS system. Three wetland types belonging to palustrine system showed no difference between Wangdungjae wetland and Mujechi wetland, but Youngnup of Mt. Daeam was different from the former two types at the level of dominant types. This fact means that setting of classification system for management of wetland is needed. Although we may never know much about the wetland resources that have been lost, there are opportunities to conserve the riches that remain. Extensive inventory of all wetland types and documentation of their ecosystem functions are vital. Unique and vulnerable examples in particular need to be identified and protected. Furthermore, a framework with which to demonstrate wetland characteristics and relationships is needed that is sufficiently detailed to achieve the identification of the integrity and salient features of an enormous range of wetland types.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.138-159
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• 1996

There has been a tendency for Geomorphology and Climatology to be dominant in Physical Geography for 50 years in Korea. Physical Geography is concerned with the study of the totality of natural environment through the integrated approaches. But, an overall direction or a certain paradigm could not be found, because major sub-divisions of Physical Geography have been studied individually and the subjects and the approaches in studying Physical Geography are enormously diverse. A consensus of opinion could not also exist in deciding what kind of the sub-divisions should be included in the physical geography in general and how those should be summarized. Furthermore it would be considered imprudent to survey the studies of Physical Geography besides those of Geomorphology and Climatology due to the small number of researchers. Assuming that the rest of Physical Geographical studies with the exception of Geomorphological and Climatological studies are the Physical Geography in general, the studies of Physical Geogrpahy in general are summarized and several aspects are drown out as follows. First the descliption of all possible factors of natural environments was the pattern of early studies of Physical Geography and the tendency is maintained in the various kinds of research and project reports. Recently Physical Geographers have published several introductory textbooks or research monographs. In those books, however, the integrated approaches to Physical Geography were not suggested and the relationship between man and nature are dealt with in the elementary level. Second, the authentic soil studies of Physical Geographers are insignificant, because the studies of soil in Physical Geography have been mostly considered as the subsidiary means of Geomorphology Summarizing the studies of Soil Gegraphy by physical geographers and other Pedologists, the subjects are classified as soil-forming processes, soil erosions, soil in the tidal flat and reclaimed land, and soil pollution. Physical Geographers have focused upon the soil-forming processes in order to elucidate the geomorphic processes and the past climatic environment. The results of other subjects are trifling. Thirdy Byogeygrayhers and the results of studies are extremely of small number and the studies of Biogeography in Korea lines in the starting point. But, Biogeography could be a more unifying theme for the Physical-human Geography interface, and it would be expected to play an active part in the field of environmental conservation and resource management. Forth, the studies of Hydrogeography (Geographical Hydrology) in Korea have run through the studies of water balance and the morphometric studies such as the drainage network analysis and the relations of various kinds of morphometric elements in river. Recently, the hydrological model have introduced and developed to predict the flow of sediment, discharge, and ground water. The growth of groundwater studies is worthy of close attention. Finally, the studies on environmental problems was no mole than the general description about environmental destruction, resource development, environmental conservation, etc. until 1970s. The ecological perspectives on the relationship between man and nature were suggested in some studies of natural hazard. The new environmentalism having been introduced since 1980s. Human geographers have lead the studies of Environmental Perception. Environmental Ethics, Environmental Sociology, environmental policy. The Physical geographers have stay out of phase with the climate of the time and concentrate upon the publication of introductory textbooks. Recently, several studies on the human interference and modification of natural environments have been made an attempt in the fields of Geomorphology and climatology. Summarizing the studies of Physical Geography for 50 years in Korea, the integrated approaches inherent in Physical Geography disappeared little by little and the majol sub-divisions of Physical Ceography have develop in connection with the nearby earth sciences such as Geology, Meteorology, Pedology, Biology, Hydrology, etc been rediscovered by non-geographers under the guise of environmental science. It is expected that Physical Geography would revive as the dominant subject to cope with environmental problems, rearming with the innate integrated approaches.

• Tuberculosis and Respiratory Diseases
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• v.48 no.4
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• pp.500-512
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• 2000

Background : To evaluate the efficacy of two methods of obtaining lung recruitment to reduce ventilator-induced lung injury(VILI). Methods : Fifteen New-Zealand white rabbits were ventilated in the pressure-controlled mode while maintaining constant tidal volume(10 ml/kg) and fixed respiration rate. Lung injury was induced by repeated saline lavage (PaO2<100 mmHg), and the pressure-volume curve was drawn to obtain Pflex. The animals were then randomly assigned to three groups and ventilated for 4 hours. In the control group(n=5), positive end-expiratory pressure(PEEP) less than that of Pflex by 3 mmHg was applied throughout the study. In the recruitment maneuver(RM) group(n=5), RM(CPAP of 22.5 mmHg, for 45 seconds) was performed every 15 minutes in addition to PEEP level less than Pflex by 3 mmHg This phrase is unclear. In the Pflex group, PEEP of Pflex was given without RM. Gas exchange, lung mechanics, and hemodynamics parameters as well as pathology were examined. Results : 1) Both the control and RM groups showed decreasing tendency in PaO2 with time. There was significantly decreased PaO2 at 4 hr compared to Ihr(p<0.05). But in the Pflex group, PaO2 did not decrease with time(p<0.05 vs other groups at 3, 4 hr). PaCO2 did not show significant difference among the three groups. 2) There was no significant difference in static compliance and plateau pressure. Mean blood pressure and heart rate also did not show any significant difference among the three groups. 3) The pathologic exam showed significantly less neutrophil infiltration in the Pflex group than in the control group(p<0.05). There was borderline significant difference in hyaline membrane score among the groups (p= 0.0532). Conclusion : Although recruitment maneuver of the injured lung may be important in decreasing VILI, it alone may not be sufficient to minimize VILI.

• Journal of Life Science
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• v.20 no.3
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• pp.437-443
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• 2010

This study was designed to examine the aerobic capacity and ventilatory response during an incremental exercise in elite high school cyclists. Twelve boys ($17{\pm}1\;yr$, $175{\pm}5\;cm$, $70{\pm}9\;kg$) participated in anthropometric measurements, incremental exercise testing, and pulmonary function tests. During incremental exercise testing using a cycle ergometer, their maximal oxygen uptake ($VO_2max$), maximal power output, ventilation, ventilatory equivalents for oxygen ($V_E/VO_2$) and carbon dioxide ($V_E/VCO_2$), respiratory rate, and tidal volume were measured. Time variables such as inspiratory time (Ti), expiratory time (Te), breathing time (Tb), and inspiratory duty cycle (Ti/Tb), as well as inspiratory flow rate ($V_T$/Ti) were assessed. Pulmonary function of vital capacity (FVC), forced expiratory volume in one second ($FEV_1$), $FEV_1$/FVC, and peak expiratory flow were evaluated. Their $VO_2max$, maximal heart rate, and Wmax were $57.5{\pm}3.9\;ml{\cdot}kg^{-1}{\cdot}min^{-1}$, $194.1{\pm}8.6\;beat{\cdot}min^{-1}$, and 452 W, respectively. $VO_2max$ was not related to any anthropometric parameters. Most ventilatory variables progressively increased with exercise intensity. As intensity increased, Ti, Tb, Tb decreased while Ti/Tb was maintained. Below an intensity of 250 W, height, weight, body mass index, and body surface were highly correlated with $V_T$/Ti and Ti/Tb (p<0.05). Collectively, $VO_2max$ appeared to be lower than adult cyclists, suggesting a different pattern of ventilatory control as age advances. Morphological characteristics were not related to $VO_2max$ in the population. Time variables of ventilatory response seemed to be related only at an exercise intensity level of less than 250 W. $V_T$/Ti may be related to exercise endurance capacity, but Ti/Tb was similar to adult cyclists.

• Tuberculosis and Respiratory Diseases
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• v.50 no.5
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• pp.540-548
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• 2001

Backgrounds : Because ventilator-induced lung injury is partly dependent on the intensity of vascular flow, we hypothesized that hypothermia may attenuate the degree of such an injury through a reduced cardiac output. Methods : Twenty-seven male Sprague-Dawley rats were randomly assigned to normothermia ($37{\pm}1^{\circ}C$)-injurious ventilation (NT-V) group (n=10), hypothermia ($27{\pm}1^{\circ}C$)-injurious ventilation (HT-V) group (n=10), or nonventilated control group (n=7). The two thermal groups were subjected to injurious mechanical ventilation for 20 min with peak airway pressure 30 cm $H_2O$ at zero positive end-expiratory pressure, which was translated to tidal volume $54{\pm}6\;ml$ in the NT-V group and $53{\pm}4\;ml$ in the HT-V group (p>0.05). Results : Pressure-volume (P-V) curve after the injurious ventilation was almost identical to the baseline P-V curve in the HT-V group, whereas it was shifted rightward in the NT-V group. On gross inspection, the lungs of the HT-V group appeared smaller in size, and showed less hemorrhage especially at the dependent regions, than the lungs of the NT-V group. [Wet lung weight (g)/body weight (kg)] ($1.6{\pm}0.1$ vs $2.4{\pm}1.2$ ; p=0.014) and [wet lung weight/dry lung weight] ($5.0{\pm}0.1$ vs $6.1{\pm}0.8$ ; p=0.046) of the HT-V group were both lower than those of the NT-V group, while not different from those of the control group($1.4{\pm}0.4$, $4.8{\pm}0.4$, respectively). Protein concentration of the BAL fluid of the HT-V group was lower than that of the NT-V group($1,374{\pm}726\;ug/ml$ vs $3,471{\pm}1,985\;ug/ml$;p=0.003). Lactic dehydrogenase level of the BAL fluid of the HT-V group was lower than that of the NT-V group ($0.18{\pm}0.10\;unit/ml$ vs $0.43{\pm}0.22\;unit/ml$;p=0.046). Conclusions : Hypothermia attenuated pulmonary hemorrhage, permeability pulmonary edema, and alveolar cellular injuries associated with injurious mechanical ventilation, and preserved normal P-V characteristics of the lung in rats.