• Korean Journal of Ecology and Environment
• /
• v.49 no.4
• /
• pp.354-374
• /
• 2016

This study explored spatiotemporal variability of water quality in correspondence with hydrometeorological factors in the five stations of Paldang Reservoir located in the Han River during 4 years from May 2012 to December 2015. Variability of basic water quality factors were largely related with seasonal fluctuations of hydrology. Temperature stratification occurred in the deep dam station, and prolonged hypoxia was observed during the draught year. Nitrogen nutrients were increased with decreasing inflow in which changing pattern of $NH_4$ reversed to $NO_3$ by the effect of treated wastewater effluent. Phosphorus increase was manifest during the period of high inflow or severe drought. Chl-a variation was reversely related with both flow change and AGP(algal growth potential) variations. Our study demonstrated that water quality variability in Paldang Reservoir was largely attributed to both natural and operational changes of inflow and outflow (including water intake) based on major pollution source of the treated wastewater (total amount of $472{\times}10^3m^3d^{-1}$) entering to the water system from watershed. In the process of water quality variability, meteorological (e.g., flood, typhoon, abnormal rainfall, scorching heat of summer) and hydrological factors (inflow and discharge) were likely to work dynamically with nutrients pulse, dilution, absorption, concentration and sedimentation. We underline comprehensive limnological study related to hydro-meteorolology to understand short- and long-term water quality variability in river-type large reservoir and suggest the necessity of P-free wastewater treatment for the effective measure of reducing pollution level of Paldang drinking water resource.

• Journal of Nutrition and Health
• /
• v.7 no.2
• /
• pp.53-63
• /
• 1974

For the elucidation of the nutritional status of residences of apartments located in various areas in Seoul city, the food and nutrition survey was undertaken by the graduate students from Department of Food & Nutrition, Ewha Womans University in 1973. The socioeconomic stratification was mainly considered for the selection of sample apartments included in this study. Hangang Mansion, KIST, Munwhachon & Bukahyun apts were selected in this respect. A. Common living circumstances. Through the questionaries, author concluded nutritional concept on everyday food life as follows; 1. Higher income seems less effective in everyday food life on the nutritional view point than higher education does. 2. It needs to be urgently improved to be accustomed to use exact measuring concept of foods when they cook. 3. It needs to be improved to serve meals for individual portion at meal table, because the portion control at meal table will effect to national food policy. B. Nutrition Survey. Average daily calroie intake was the highest in Hangang Mansion and lowest in Bukahyun apt., in accordance with their economic living standard, but most of their calorie intakes were lower than the R.D.A. (3000ca1 for male, 2200 Cal for female). But the composition ratio of the total calorie intake was near to the ideal, carbohydrate 60%, protein 15%, fat 25%. Although there were differences in their economic living situations in urban area, most people ingested relatively good quality and large amounts of protein and fat. Vitamin A and Niacine intake exceeded the R.D.A., but the intake of Ca, Thiamine, Riboflavin, Ascorbic Acid were far less than that of R.D.A. C. food Intake. Amounts of total daily food intake were highest in Bukahyun apt. and lowest in Hangang Mansion. These showed adverse aspects to the total calorie intakes and their income levels. The ratio of cereals, $40%{\sim}50%$ of the total food intake, was higher than any other kinds of foods in all apartments. Among the other foods except cereals, there represented the highest level of meats in Hangang Mansion and KIST apt., while intake of Kimchies were highest in Munwhachon and Bukahyun apt. In the case of vegetables and fruits intake, the ratio of them in Hangang Mansion and KIST apt. were high, on the other hand the ratio of starchy roots appeared lowest in Hangang Mansion. For the main sources of protein, meats were ingested in Hangang Mansion and KIST apt., meats and fishery were used in Munwhachon apt., and beans were eaten highly in their meals in Bukahyun apt. These food contents and distributions showed the significant differences not only their economic classes but also regional characteristics.

• Journal of Korean Society of Forest Science
• /
• v.79 no.2
• /
• pp.144-161
• /
• 1990

Pine forest communities developed in Mt. Palgong, southeastern Korea, were studied phytosociologically, with special reference to multiple management of local forests, and were classified into two communities, Pinus densiflora - Quercus mongolica community(I : mountain forest) and P. densiflora-Climbing plants community (II : valley forest) and six subgroups accompanied by several subgroups. Judging from the coincidence method, the division of communities (vegetation units) was closely related to altitude and topography. Based on vegetation units, a vertical distribution map of pine forest communities was prepared. The species composition(%) of pine forest communities under stratification, in upper and lower tree layer, teas I higher than II, in middle and shrubs lacer II higher than I (Total : Upper 15.5%, Middle 28.4%, Lower 34.6%. Shrubs 21.5%. Sum of mean coverage%i of understory vegetation was II twice as high as I (Total. shrubs 28.4%. forbs 11.4%, Graminoids 11.8%, ferns 1.0%). Based on constance, coverage and d.b.h. class etc., an actual growth and occurrence table of tree species and understory vegetation by vegetation unity were prepared, and could assume a criterion for judging potential dominance-growth conditions.

• Journal of the Korean earth science society
• /
• v.42 no.5
• /
• pp.536-555
• /
• 2021

Sea-surface wind is an important variable in ocean-atmosphere interactions, leading to the changes in ocean surface currents and circulation, mixed layers, and heat flux. With the development of satellite technology, sea-surface winds data retrieved from scatterometer observation data have been used for various purposes. In a complex marine environment such as the Korean Peninsula coast, scatterometer-observed sea-surface wind is an important factor for analyzing ocean and atmospheric phenomena. Therefore, the validation results of wind accuracy can be used for diverse applications. In this study, the sea-surface winds derived from ASCAT (Advanced SCATterometer) mounted on MetOp-A/B (METeorological Operational Satellite-A/B) were validated compared to in-situ wind measurements at 16 marine buoy stations around the Korean Peninsula from January to December 2020. The buoy winds measured at a height of 4-5 m from the sea surface were converted to 10-m neutral winds using the LKB (Liu-Katsaros-Businger) model. The matchup procedure produced 5,544 and 10,051 collocation points for MetOp-A and MetOp-B, respectively. The root mean square errors (RMSE) were 1.36 and 1.28 m s^-1, and bias errors amounted to 0.44 and 0.65 m s^-1 for MetOp-A and MetOp-B, respectively. The wind directions of both scatterometers exhibited negative biases of -8.03° and -6.97° and RMSE values of 32.46° and 36.06° for MetOp-A and MetOp-B, respectively. These errors were likely associated with the stratification and dynamics of the marine-atmospheric boundary layer. In the seas around the Korean Peninsula, the sea-surface winds of the ASCAT tended to be more overestimated than the in-situ wind speeds, particularly at weak wind speeds. In addition, the closer the distance from the coast, the more the amplification of error. The present results could contribute to the development of a prediction model as improved input data and the understanding of air-sea interaction and impact of typhoons in the coastal regions around the Korean Peninsula.

• The Korean Journal of Medicine
• /
• v.93 no.6
• /
• pp.538-547
• /
• 2018

Background/Aims: The impact of left ventricular (LV) diastolic function and filling pressure on clinical outcomes in young patients with acute myocardial infarction (AMI) has been poorly studied. Therefore, the aim of this study was to investigate the impact of LV diastolic function and LV filling pressure on major adverse cardiac events (MACEs) in young patients with AMI. Methods: A total of 200 young patients (males < 45 year, females < 55 year) with AMI were divided into two groups according to the diastolic function; normal (n = 46, $39.5{\pm}5.3$ years) versus abnormal (n = 154, $43.5{\pm}5.1$ years). Results: Despite regional wall motion abnormalities, normal LV diastolic function was not uncommon in young AMI patients (23.0%). During the 40 months of clinical follow-up, MACEs developed in 26 patients (13.0%); 14 re-percutaneous coronary intervention (7.0%), 8 recurrent MI (4.0%), and 4 deaths (2.0%). MACEs did not differ between the normal and abnormal diastolic function group (13.6% vs. 10.9%, p = 0.810), but MACEs were significantly higher in the high LV filling pressure group than the normal LV filling pressure group (36.8% vs. 10.5%, p < 0.001). On multivariate analysis, high LV filling pressure was an independent predictor of MACEs (hazard ratio 3.022, 95% confidence interval 1.200-7.612, p = 0.019). Conclusions: This study suggested that measurement of the LV filling pressure (E/e' ratio) would be useful in the risk stratification of young patients with AMI. However, it would be necessary to monitor this category of patient more carefully.

• The Journal of the Petrological Society of Korea
• /
• v.28 no.2
• /
• pp.111-128
• /
• 2019

Ulleung Island is the top of an intraplate alkalic volcano rising 3200 m from sea floor in the East Sea (or Sea of Japan). The emergent 984.6 m consist of eruptive products of basaltic, trachytic and phonolitic magmas, which are divided into Dodong Basaltic Rocks, and Ulleung, Seonginbong and Nari groups. The Maljandeung Tuff in the Nari Group consists of thick pyroclastic sequences which are subdivided into 4 members (N-5, U-4, 3, 2), generating from explosive eruptions during past 18.8~5.6 ka B.P. From chemical data, the Member N-5, phonolitic in composition, is considerably enriched in incompatible elements and REE patterns with significant negative Eu anomalies. The members 4, 3 and 2 are phonolitic to tephriphonolitic in composition, and their REE patterns do not have significant Eu anomalies. In variation trend diagrams, many elements show abrupt compositional gaps between members, and gradual upward-mafic variations from phonolite to tephriphonolite within each member. It suggests a downward-mafic zonation that were evolved into phonolitic zone in the lower part to tephriphonolitic zone in upper part of magma chamber. It is supposed that the chemical stratification generated from multiple mechanisms of thermal gravidiffusion, crystal fractionation, and gradual melting and sequential emplacement. The stratified magmas were explosively erupted to generate a small caldera during short period (11 ka B.P.). Especially both members (U-3, 2) were accumulated by gradually erupting from the upper phonoltic zone to the lower tephriphonoltic zone of the stratified chamber in 8.4 ka B.P. and 5.6 ka B.P. time, respectively.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.4
• /
• pp.457-467
• /
• 2019

To investigate the long-term variation characteristics of nutrients in the east coast of Korea, water temperature, salinity, dissolved oxygen, and nutrients were measured at three stations of Sokcho, Jukbyeon and Gampo coasts for five years from 2013 to 2017. For five years, the water temperature of the East Sea coast was in the range of $1.2{\sim}28.8^{\circ}C$, the salinity was in the range of 30.63~34.79 and the dissolved oxygen (DO) was in the range of 3.53~7.64 mL/L. Distribution and variation of the water environment factors in the study area were determined by the vertical stratification of water column and distribution of water temperature. The high DO concentration in Sokcho coast From 2015 to August 2016 is presumed to be the result of the southward inflow of North Korean Cold Water (NKCW). Concentrations of dissolved inorganic nitrogen (DIN, $NH_4-N+NO_2-N+NO_3-N$) ranged $0.11{\sim}24.19{\mu}M$, phosphate concentration ranged $0.01{\sim}1.75{\mu}M$, and silicate ranged $0.17{\sim}32.80{\mu}M$. The N:P ratio was in the range of 0.7~54.3 (mean 15.2) and the N:P slope was in the range of 11.67~13.75. The N:P ratios in this study were lower than the Redfield ratio (16), indicating that nitrate did act as a limiting factor in phytoplankton growth. The correlation ($R^2$) of total N:P ratio was as high as 0.95, indicating that the effect of the surrounding land or non-point sources was not significant. In conclusion, the spatial and temporal variation of nutrients in the east coast of Korea was determined by the vertical mixing of water mass with thermocline and mainly affected by physical factors such as influx of external water masses and coastal upwelling, and the influences from inflows from the land were minimal.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.647-658
• /
• 2018

The aim of this study is to investigate the seasonal changes of phytoplankton communities based on the environmental changes in a dense oyster farming area (Hansan-Geoje Island) from June to December 2016. The water temperature varied from $14^{\circ}C$ to $28.8^{\circ}C$ and its salinity ranged from 29.4 to 34.2 psu. Nitrate+nitrite was kept at c.a. $3.0{\mu}M$ on the surface layer from June to July, below the concentration limit in August and early September, and then gradually increased from late September. Ammonia was high on July 20 and August 10, and its seasonal characteristics were not clear. Phosphate ranged from 0.01 to $0.7{\mu}M$ on the surface layer, and its seasonal changes were similar to those of nitrate+nitrite. Mean silicate concentrations were $10.7{\mu}M$ on the surface and $15.7{\mu}M$ in the bottom layer, and it was not acted as a limiting factor for the growth of phytoplankton. Among the phytoplankton community, Bacillariophyceae, Dinophyceae and Cryptophyceae was 61.2%, 22.5%, and 13.6%, respectively. In late June, dinoflagellate Prorocentrum donghaiense was dominant in the outer waters(St. T1), later on, Cryptomonas spp. and Chaetoceros spp. were dominant, respectively. From late September to October, diatoms Pseudo-nitzschia spp. and Chaetoceros spp. were stimulated under non-stratified condition after the typhoon. In December, A. sanguinea was found to be $1.7{\times}10^5cells\;L^{-1}$. Seasonally, relative high phytoplankton biomass may be favorable to maintain high production of filter feeder oyster in the dense oyster farming areas of Hansan and Geoje Island.

• Korean Journal of Environmental Biology
• /
• v.37 no.1
• /
• pp.93-108
• /
• 2019

To investigate the temporal-spatial distribution of picophytoplankton in relation to different water masses in the northern East China Sea (ECS), picophytoplankton abundance were investigated using flow cytometry with environmental factors in 2016-2017. The results from the analysis of flow cytometer data showed that Synechococcus appeared across all seasons, exhibiting its minimum abundance in winter and maximum abundance in summer. Furthermore, high abundance was detected in the surface mixed layer during spring and summer when vertical stratification occurs; in particular, Synechococcus exhibited maximum abundance in thermocline layer, indicating a close correlation to water temperature and thermocline formation. In addition, the abundance of Synechococcus indicated a decrease in the western seas in 2017 compared to 2016 under the strong influence of the Changjiang Diluted Water (CDW). This was determined by the significant influence of the CDW on the abundance of Synechococcus during summer in the northern waters of the ECS. In contrast, Prochlorococcus did not appear during winter and spring, and its distribution was limited during summer and autumn in the eastern seas under the influence of the Kuroshio current. The largest range of Prochlorococcus distribution was confirmed during autumn without the influence of the CDW. Thus, the distribution pattern of each picophytoplankton genus was found to be changing in accordance to the extension and reduction of sea current in different seasons and periods of time. This is anticipated to be a useful biological marker in understanding the distribution of sea currents and their influence in the northern waters of the ECS.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.36 no.4
• /
• pp.113-123
• /
• 2018

The purpose of this research is to develop evaluation indicators forperformance improvement of horticultural therapy garden. In order to achieve a therapeutic purpose, the gardening activity held by the trained horticultural therapist. Moreover, horticultural therapy is 'a medical model' for the treatment and basic premise of the research was set, as horticultural therapy garden is characterized area to support activities of patients and horticultural therapist functionally and efficiently. For this study, three times of Delphi and AHP techniques were proceeded to export panels who were recruited by purposive sampling. Through these techniques, it was possible to deduct the evaluation indicator which maximizes the performance of the horticultural therapy garden. The evaluation items were prioritized by typing and stratification of the indicator. The results and discussions were stated as followings. Firstly, a questionnaire of experts was conducted to horticultural therapists and civil servants who were in charge of horticultural therapy. As results(horticultural therapists: 87.8%, civil servants: 75.2%), It is possible to conclude that both positions have the high recognition and agreed on the necessity of horticultural therapy. Secondly, Delphi investigation was conducted three times in order to develop the evaluation indicator for performance evaluation. After Delphi analysis, total 34 of evaluation elements to improve the performance of the horticultural therapy garden by reliability and validity analysis results. Thirdly, AHP analysis of each evaluation indicator was conducted on the relative importance and weighting. Moreover, the results showed 'interaction between nature and human' as the most important element, and in order of 'plan of the program', 'social interaction', 'sustainable environmental', and 'universal design rule', respectively. On the other hand, the exports from the university and research institute evaluated the importance of 'interaction between nature and human', while horticultural therapists chose 'plan of the program' as the most important element. Fourthly, the total weight was used to develop weight applied evaluation indicator for the performance evaluation of the horticultural therapy garden. The weight applying to evaluation index is generally calculated multiply the evaluation scores and the total weight using AHP analysis. Finally, 'the evaluation indicator and evaluation score sheet for performance improvement of the horticultural therapy garden' was finally stated based on the relative order of priority between evaluation indicators and analyzing the weight. If it was deducted the improvement points for the efficiency of already established horticultural therapy garden using the 'weight applied evaluation sheet', it is possible to expand it by judging the importance with the decision of the priority because the item importance decided by experts was reflected. Moreover, in the condition of new garden establishment, it is expected to be helpful in suggesting ways for performance improvement and in setting the guidelines by understanding the major indicators of performance improvement in horticultural therapy activity.