• Journal of Korean Society of Coastal and Ocean Engineers
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• v.26 no.3
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• pp.160-173
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• 2014

Seabed beneath and near coastal structures may undergo large excess pore water pressure composed of oscillatory and residual components in the case of long durations of high wave loading. This excess pore water pressure may reduce effective stress and, consequently, the seabed may liquefy. If liquefaction occurs in the seabed, the structure may sink, overturn, and eventually increase the failure potential. In this study, to evaluate the liquefaction potential on the seabed, numerical analysis was conducted using the expanded 2-dimensional numerical wave tank to account for an irregular wave field. In the condition of an irregular wave field, the dynamic wave pressure and water flow velocity acting on the seabed and the surface boundary of the composite breakwater structure were estimated. Simulation results were used as input data in a finite element computer program for elastoplastic seabed response. Simulations evaluated the time and spatial variations in excess pore water pressure, effective stress, and liquefaction potential in the seabed. Additionally, the deformation of the seabed and the displacement of the structure as a function of time were quantitatively evaluated. From the results of the analysis, the liquefaction potential at the seabed in front and rear of the composite breakwater was identified. Since the liquefied seabed particles have no resistance to force, scour potential could increase on the seabed. In addition, the strength decrease of the seabed due to the liquefaction can increase the structural motion and significantly influence the stability of the composite breakwater. Due to limitations of allowable paper length, the studied results were divided into two portions; (I) focusing on the dynamic response of structure, acceleration, deformation of seabed, and (II) focusing on the time variation in excess pore water pressure, liquefaction, effective stress path in the seabed. This paper corresponds to (I).

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.430-446
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• 2018

To improve understanding of the sources and chemical properties of particulate pollutants on the Korean Peninsula, An Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) measured non-refractory fine particle ($NR-PM_1$) from 2013 to 2015 at Baengnyeong Island and Seoul metropolitan area (SMA), Korea. The chemical composition of $NR-PM_1$ in Baengnyeong island was dominated by organics and sulfate in the range of 36~38% for 3 years, and the organics were the dominant species in the range of 44~55% of $NR-PM_1$ in Seoul metropolitan area. The sulfate was found to be more than 85% of the anthropogenic origin in the both areas of Baengnyeong and SMA. Ratio of gas to particle partition of sulfate and nitrate were observed in both areas as more than 0.6 and 0.8, respectively, representing potential for formation of additional particulate sulfate and nitrate. The high-resolution spectra of organic aerosol (OA) were separated by three factors which were Primary OA(POA), Semi-Volatility Oxygenated Organic Aerosol (SV-OOA), and Low-Volatility OOA(LV-OOA) using positive matrix factorization (PMF) analysis. The fraction of oxygenated OA (SOA, ${\fallingdotseq}OOA$=SV-OOA+LV-OOA) was bigger than the fraction of POA in $NR-PM_1$. The POA fraction of OA in Seoul is higher than it of Baengnyeong Island, because Seoul has a relatively large number of primary pollutants, such as gasoline or diesel vehicle, factories, energy facilities. Potential source contribution function (PSCF) analysis revealed that transport from eastern China, an industrial area with high emissions, was associated with high particulate sulfate and organic concentrations at the Baengnyeong and SMA sites. PSCF also presents that the ship emissions on the Yellow Sea was associated with high particulate sulfate concentrations at the measurement sites.

• Journal of radiological science and technology
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• v.36 no.4
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• pp.263-271
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• 2013

The decrease of bone mineral density gives rise to the outbreak of osteopenia and makes the possibility of a bone fracture. It makes health problems in society. It's very important to prevent osteopenia in advance. Also it's critical to prevent and take care of it in adolescent because it's the most developing period comparing to middle ages because that bone mineral density decreases. There are genetic, physical and enviromental factors that affect bone mineral density. Recently, a lifestyle and eating habits are also changing as the society atmosphere is gradually doing. This study have shown that 134 women and 75 men was chosen and responded to the survey of measuring bone mineral density and investigating a lifestyle. The measure of bone mineral density is to use Dual energy X-ray absorptiometry(DEXA) and check femoral neck and lumbar spine. Also questionaries was required to pre-made survey about their lifestyles. Analysis of data was done with SPSS program. Multiple regression analysis was used for the relation of bone mineral density, the heigths and BMI. The sample of Groups are checked for drinking, smoking or excercising about differences by t-test. The results of the experiments were; first, there is statistically significant differences in the comparisons between BMD and BMD. But there isn't any special correlation between drinking, smoking and BMD. Secondly, bone mineral density becomes low related to an intake of caffeine. Particularly, this is statically significant on women. Also there is statically significant correlation between femoral neck and quantity of motion for both men and women. Third, there is significant relation between eating habits and bone mineral density on women's lumbar spine. However, there is no significant relation between men's lumbar spine and women's one. Therefore, to prevent osteopenia, it's good to abstain from intaking caffeine within an hour after a meal. In addition, it's helpful to walk or run regularly and have a balanced meal.

• Journal of the Korean Society of Food Culture
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• v.6 no.4
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• pp.393-401
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• 1991

In order to compare the food consumption pattern of college girls on weekday and Sunday, the food intake of college girls in a district of Pusan city was analyzed through the factor analysis method. The principal results are as follows. 1. The amount of food intake on Sunday was generally larger than the average values of the food intake on weekday except for soybean & products, meats and beverage. 2. As for correlation coefficients among the intake of each food group, on weekday, positive correlation was noted among rice, potatoes, soybean & products and sea-weeds, fish & shells and fat & oil. And confectionery & sugar showed also a positive correlation to bread, while, on Sunday, vegetables, sea-weeds and meats showed a positive correlation to rice, and other cereals and eggs showed a positive correlation to bread & noodles, too. As for the relationship among rice and bread & noodles, a negative correlation was noted both on weekday and Sunday. 3. As for the factor analysis of the food intake on weekday through the correlation matrix, in the first factor, soybean & products, fat & oil, sea-weeds, rice and fish & shells showed comparatively large factor load, and in the second factor, meats, kimchi, vegetables, soybean & products, fruits and fish & shells showed large factor load. Here the first factor showed the Korean dietary life and the second factor showed subsidiary food (control nutrient) factor. In case of the food intake on Sunday, in the first factor, rice, meats, sea-weeds, soybean & products and vegetables showed large factor load, and in the second factor, fish & shells, vegetables, fat & oil, fruits and rice showed large factor load. Accordingly, the first factor and the second factor were considered to show Korean dietary pattern. 4. Nutrient intake on weekday and Sunday was substantially sufficient to RDA except for energy and iron.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.405-414
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• 2008

To better understand the physical processes that control the high-latitude lower thermospheric dynamics, we analyze the divergence and vorticity of the high-latitude neutral wind field in the lower thermosphere during the southern summertime for different IMF conditions. For this study the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEG CM) is used. The analysis of the large-scale vorticity and divergence provides basic understanding flow configurations to help elucidate the momentum sources that ulti-mately determine the total wind field in the lower polar thermosphere and provides insight into the relative strengths of the different sources of momentum responsible for driving winds. The mean neutral wind pattern in the high-latitude lower thermosphere is dominated by rotational flow, imparted primarily through the ion drag force, rather than by divergent flow, imparted primarily through Joule and solar heating. The difference vorticity, obtained by subtracting values with zero IMF from those with non-zero IMF, in the high-latitude lower thermosphere is much larger than the difference divergence for all IMF conditions, indicating that a larger response of the thermospheric wind system to enhancement in the momentum input generating the rotational motion with elevated IMF than the corresponding energy input generating the divergent motion. the difference vorticity in the high-latitude lower thermosphere depends on the direction of the IMF. The difference vorticity for negative and positive $B_y$ shows positive and negative, respectively, at higher magnetic latitudes than $-70^{\circ}$. For negative $B_z$, the difference vorticities have positive in the dusk sector and negative in the dawn sector. The difference vorticities for positive $B_z$ have opposite sign. Negative IMF $B_z$ has a stronger effect on the vorticity than does positive $B_z$.

• Journal of Nutrition and Health
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• v.48 no.3
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• pp.248-257
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• 2015

Purpose: The aim of this study was to estimate total sugar intake and sugar intake-related dietary habit and nutrient intake of middle school students. Methods: Subjects included 1,184 middle school students (476 males and 708 females) residing in Jeju. This research analyzed daily dietary intakes of subjects using the 24 hour recall method and surveyed the dietary habit related to total sugar intake using questionnaires. Descriptive analysis, chi-square test, t-test, and ANOVA, using the SAS program were used for analysis of data. Results: The average daily total sugar intake was 60.3 g (male 50.5 g, female 66.9 g). Total sugar intake per meal was 6.5 g (10.8%) from breakfast, 9.0 g (14.9%) from lunch, 11.8 g (19.6%) from dinner, and 33.0 g (54.7%) from snacks. Food groups that contribute to the majority of total sugar intake were grains and their products (23.0 g), milk (11.0 g), fruits and their products (7.3 g), sugars and sweets (6.1 g), and vegetables and their products (5.8 g). In terms of total sugar intakes by cooking methods, desserts showed a greater amount than main and side dishes, and indicated in order of amount as follows: bread and cookies (11.5 g), dairy products (7.5 g), ice cakes (6.2 g), beverages (5.3 g), and fruits (4.5 g). Total sugar consumption was high for rice and side dishes such as noodles (10.2 g), fried foods (2.9 g), stir-fried foods (2.0 g), and cooked rice with seasoning (1.7 g). The daily intake of natural sugar, added sugar, and natural and added sugar was 18.3 g, 35.8 g, and 6.2 g, respectively. The high sugar intake group, which was over 20% of the energy from total sugar intakes, consumed significantly less Fe, Zn, vitamin B6, niacin, and vitamin E than the low sugar intake group, which was below 20%. Conclusion: Total sugar intake of second graders of middle schools on Jeju Island was 60.3 g/day, mostly obtained from snacks (54.7%). Therefore, nutritional education for proper selection of better snacks and for reduction of dietary sugar intake is needed for middle school students.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.490-503
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• 2020

Oceanic current and circulation have played an important role as regulators of the earth's energy distribution. The science and earth science textbooks for secondary schools based on the 2015 revised curriculum included a misconception of the seasonal variation of the North Korea Cold Current (NKCC) among the currents around the Korean Peninsula. To analyze this, the contents related to the NKCC were collected in the textbooks of five middle and six high schools, and a questionnaire survey was conducted on 30 middle school science teachers. The survey consisted of questions about whether the textbook mentions the NKCC and whether there is an error in the concept of the temporal variation of the NKCC, and the teachers' free opinions related to the NKCC were collected. The textbooks suggest that the NKCC is strongest in winter, which is not consistent with scientific findings so far. In fact, there is scientific evidence that the NKCC is the strongest in the summer. In this study, the causes and processes of misconceptions were investigated. According to an analysis of the survey, most teachers had an knowledge that the NKCC is stronger in winter. These errors began with a misconception of the terms, which teachers had imprinted on their memory as firm knowledge. These misconceptions originated from the knowledge that teachers themselves acquired from their secondary school years and have long been transferred back to teachers and students without revising the misconceptions of textbooks. This situation is expected to have a seriously recurrent structure that produces students' serious misconceptions in the future. Therefore, this study summarizes existing results on the seasonal variability of the NKCC and suggests the necessity for re-education to improve teachers' professionalism and to eliminate the misconceptions of teachers and students.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.718-732
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• 2013

The purpose of this study was to provide data for the basic research to found the effective conservation and management plan for the Geumdangsil Pine Forest of Yecheon designated as Natural Monument No. 469. Furthermore, this paper suggest efficient sustainable forest preservation and using. In order to achieve the sustainable forest preservation, this study was to analyse topography, land use, tree growth, soil environment, forest usage and forest management, etc. According to analysis the results, the site area is located in the flatlands where is from 130 to 140 m above sea level. The around forest was transformed into agricultural land. The 565 individuals of Pinus densiflora grows in the forest, whereas, 25 trees was cut down or died. There are signs of 25 stumps. The most of 565 trees' diameter at breast height(DBH) was centerized between 30 cm and 50 cm, moreover, the average life expectancy of trees were 85.4 years. The oldest age of tree was estimated to be 200 years. The Sample trees of rate of branch growth is from 4.3 cm to 5.1 cm per year. The middle branch which is more vigorous growth grow 24.2 cm for 3 years. Moreover, the result of soil physico-chemical properties analysis of 7 plots, 4 categories which is soil organic matter, total nitrogen, available phosphoric acid, specific electrical conductance was generally good, however, the 2 categories which is soil pH, exchangeable cation needed improvement. Currently, the site was not pressured by facilities and usage, however, there might be threaten by agriculture such as encroaching on forest. Therefore, there should establish comprehensive ecosystem management such as facility management, visitors management and operation management In this paper considered 4 fields that is ecosystem management, facility management, visitors management and operation management for sustainable management.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.689-700
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• 1996

Fisheries products have to be produced and maintained by work processes from the environment, sometimes helped by people. In Korean fisheries both environmental production and its economic use are included within the windows of system approach. EMERGY is the sum of all inputs expressed as one form of solar energy required directly and indirectly to make a product. Calculating EMERGY flows into Korean fisheries evaluates the real wealth contributed by environmental production and its economic use. Several indices calculated from EMERGY analysis table and a three-arm diagram give perspective on the type and efficiency of the environmental uses. Net EMERGY yield ratio is a measure of its net contribution to the economy beyond its own operation. For adjacent waters fisheries in Korea, the net contribution to the economy is 11.85 or higher, which is a stimulus to the economy that is able to purchase it. EMERGY investment ratio measures the intensity of the economic development and the loading of the environment. The ratio for Korean fisheries as a whole is 0.50, for the adjacent waters fisheries 0.09 and for the shallow-sea cultures 1.28, which is lower than the same index for the industry of the developed country (7.0). The component of environment drawn into production are large compared to purchased investment in Korean fisheries. Much more EMERGY is contained in fisheries products than in the paid services used to process the products. The EMERGY exchange ratio for Korean fisheries as a whole is 6.98, for the adjacent waters fisheries is 10.69 and for the shallow-sea cultures is 1.25. Using market values to evaluate wealth of environment resources is found to be many times too small. Money is paid only to people for their contribution, and never to the environment for its contribution. Macroeconomic value is the appropriate measure for discussing large-scale considerations of an economy, including environment and human goods & services.

• Economic and Environmental Geology
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• v.49 no.5
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• pp.381-388
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• 2016

The purpose of this study is to integrate and visualize using mapping techniques based on precise seabed geomorphology, seafloor backscattering images and high-resolution underwater images of the nearshore area around the Dokdo, in the East Sea. We have been obtained the precise topography map using multibeam echosounder system around the nearshore area(~50 m) of the southern part of the Seodo. Side scan sonar survey for analysis seafloor backscattering images was carried out in the same area of topography data. High-resolution underwater images(zone(a), zone(b), zone(c)) were taken in significant habitat scope of the nearshore area of the southern part of the Seodo. Using the results of bathymetry, seafloor backscattering images, high-resolution underwater images, we performed an integrated visualization about the nearshore area of the Dokdo. The integrated visualizing techniques are possible to make the seabed characteristic mapping results of the nearshore area of the Dokdo. The integrated visualization results present more complex and reliable information than separate geological products for seabed environmental mapping study and it is useful to understand the relation between seafloor characteristics and topographic environments of the study area. The integrated visualizing techniques and mapping analysis need to study sustainably and periodically, for effective monitoring of the nearshore ecosystem of the Dokdo.