• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.2
• /
• pp.80-89
• /
• 2009

The rates of sediment oxygen demand(SOD) and denitrification(DNF) were measured using $^{15}N$ isotope pairing technique in intact sediment cores in the shelf of Dok Island. The SOD and DNF in the continental shelf of Dok Island were ranged from 1.04 to $9.08\;mmol\;m^{-2}\;d^{-1}$ and from 7.06 to $37.67\;{\mu}mol\;m^{-2}\;d^{-1}$, respectively. The SOD and DNF values in this study are higher than typical deep sea sediment. The SOD and DNF in this study were high in the high organic matter content sediment and high organic matter content was promotive of coupled nitrification-denitrification. Organic carbon contents in surface sediment ranged from 1.8 to 2.4%, which is higher than typical deep sea sediments. Therefore we conclude that the organic matter content in surface sediment is determined by the nature of the export production not the water depth in East sea sediment and the nature of the export production also determines remineralization processes such as SOD and DNF in East sea/Ulleung Basin sediment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.3
• /
• pp.127-133
• /
• 2009

In order to determine organic carbon oxidation by manganese and iron oxides, six core sediments were obtained in slope and basin sediments of Ulleung Basin in East Sea. The basin sediments show high organic carbon contents (>2%) at the water depths deeper than 2,000 m; this is rare for deep-sea sediments, except for those of the Black Sea and Chilean upwelling regions. In the Ullleung Basin, the surface sediments were extremely enriched by Manganese oxides with more than 2%. Maximum contents of Fe oxides were found at the depth of $1{\sim}4cm$ in basin sediments. However, the high level of Mn and Fe oxides was not observed in slope sediment. Surface manganese enrichments (>2%) in Ulleung Basin may be explained by two possible mechanisms: high organic carbon contents and optimum sedimentation rates and sufficient supply of dissolved Manganese from slope to the deep basin. Reduction rates of iron and manganese oxides ranged from 0.10 to $0.24\;mmol\;m^{-2}day^{-1}$ and from 0.30 to $0.57\;mmol\;m^{-2}day^{-1}$, respectively. In Ulleung Basin sediments, $13{\sim}26%$ of organic carbon oxidation may be linked to the reduction of iron and manganese oxides. Reduction rates of metal oxides were comparable to those of Chilean upwelling regions, and lower than those of Danish coastal sediments.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.14 no.3
• /
• pp.171-180
• /
• 2009

Based on the constituent analysis of sediments near Dok Island, the origin and sedimentary facies were Investigated. The sediments are mainly from originated from volcanic and volcaniclastic rock fragments derived from Dok Island and carbonate sediments formed by a variety of shallow-dwelling organisms that secreted calcareous skeletons. Carbonate producers include mollusks (bivalves and gastropods), encrusting & branching bryozoans, encrusting & segmented red algae, worm tubes, barnacles, diatoms, sponge spicules and echinoderm fragments. The distribution and relative amount of these constituents are basically dependent upon water depth and grain size even though local variations can be observed within the same depth interval. Five sedimentary facies can be divided: nearshore facies (<20 m), neritic facies ($20{\sim}100m$), upper transitional facies ($100{\sim}200m$), lower transitional facies ($200{\sim}700m$), and hemipelagic facies (>700 m). The sediments that were sampled below the water depth of 2,000 m still contain a significant amount of carbonates (ca. $10{\sim}20%$), implying that the carbonate compensation depth in the East Sea may well exceed this water depth.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.12 no.4
• /
• pp.280-286
• /
• 2007

In order to find out the effects of the anticyclonic eddy on the distribution of nutrients and chlorophyll concentrations in the Ulleung Basin during spring and summer, we measured temperature, salinity, nutrients, and chlorophyll from the surface to 200 m water depth at five stations in July 2005 and April 2006. In spring, surface mixed layer was very deep inside the eddy, about 200 m, but it was relatively shallow outside the eddy, about $20{\sim}60$ m. Inside of the eddy, nutrients in the surface waters were sufficient by supply from the deep layer, whereas outside of the eddy, they were fairly depleted due to the stratification in the surface layer. In spring, chlorophyll concentrations were relatively low inside of the eddy due to the deeper surface mixed layer compared with the euphotic depth, and the depth-integrated chlorophyll concentrations outside of the eddy were twice as much as those inside of the eddy. In summer, nutrients in the surface waters were completely depleted at all stations due to the well stratification in the surface layer. The typical distribution pattern of subsurface chlorophyll maximum was observed at all stations, and the depth-integrated chlorophyll concentrations inside of the eddy were almost twice as much as those outside of the eddy. The anticyclonic eddy appearing in the Ulleung Basin every year significantly affects the phytoplankton biomass, with the opposing effects in spring and summer; in spring, the anticyclonic eddy suppresses phytoplankton growth, but in summer, it enhances the phytoplankton biomass.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.2
• /
• pp.237-244
• /
• 2024

We studied the effects on their academic achievement of chemistry II and advanced chemistry subjects of science high school students according to the type of class (face-to-face and non-face-to-face). The subjects of this study were 195 first-year students of G Science High School located in Gyeongnam. The average scores of Chemistry II and Advanced Chemistry in non-face-to-face classes in 2020 and face-to-face classes in 2021 were compared and analyzed. As a result of comparing and analyzing the academic achievement according to the class type, students' grades in Chemistry II and Advanced Chemistry were higher in non-face-to-face classes. In the comparison of academic achievement by level according to class type, Chemistry II showed higher average grades in non-face-to-face classes as the lower level were, and in advanced chemistry, the higher the upper grades in non-face-to-face classes. In addition, in terms of the effect of changes in class form on the upper and lower 10% levels of academic achievement of Chemistry II, the upper 10% showed high grades in face-to-face classes and the lower 10% in non-face-to-face classes. On the other hand, in advanced chemistry, the average grade of non-face-to-face classes was higher than that of face-to-face classes in the top 10%, and the average grade of face-to-face classes was higher than that of non-face-to-face classes in the bottom 10%. Through these results, it was found that in the teaching-learning of science high school students, instructors need to design and treat teaching-learning appropriate to the level of academic achievement.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.37 no.4
• /
• pp.60-72
• /
• 2019

The purpose of this study was to identify detailed factors that affect visitor satisfactions of the plants on display, environments of pedestrian road and facility of each theme garden by conducting a survey of visitors to Jade Garden. The 400 data including 100 copies per theme garden were used for statistical analysis. The statistical techniques used in the survey analysis include multi-regression analysis, t-test, and analysis of variance(ANOVA). As a result of the analysis, most of theme gardens tended to have the greatest impact on the satisfaction of the plants on display and the lowest level of facility satisfaction. According to detailed factors analysis of the satisfaction of plants on display satisfaction of plant diversity and the method of plant display were most affected in most of the theme gardens. Among them, promoting the satisfaction of plant diversity is necessary to plant various species, but in case of Ginkgo Maze Garden, a type of tree community as one tree(Ginkgo biloba), the satisfaction of plants diversity did not show a rising-up value. Therefore, it was confirmed that the appropriate degree of plants diversity depends on the theme or environment of the garden. In the case of the pedestrian-road-satisfaction, the width of the pedestrian road was the most affected, It was analyzed that whether the point of intersection can be easily available during peak season has a significant impact on the satisfaction of visitors. In the case of facility satisfaction, it was analyzed that the presence of rest and convenience facilities had the most direct influence on visitors, so the facility diversity had the greatest influence. Therefore, it is necessary to more systematically categorize and consider the influential detailed factors such as plants diversity and methods of plant display, width of pedestrian road and facilities diversity for the management and development of the arboretum.

• Korean Journal of Food Science and Technology
• /
• v.51 no.6
• /
• pp.509-516
• /
• 2019

In this study, the general components, particle size, starch content, hydrolysis index (HI), and estimated glycemic index (eGI) of 'Ilpum', a medium-amylose rice cultivar, were compared with those of 'Dodamssal', a high-amylose rice cultivar containing resistant starch. The volume weighted mean was significantly smaller in 'Dodamssal' than in 'Ilpum'. The resistant starch content of 'Dodamssal' was about 13% and there were no differences in terms of particle size. The HI and eGI were found to be significantly higher in 'Ilpum', and there were no statistical differences in 'Dodamssal' except for samples with an average particle size of less than 50 ㎛. Therefore, 'Dodamssal' was concluded to be valuable as a health-food material since it is easily ground evenly when processed into rice flour, contains resistant starch, and has a low glycemic index. These results could be used as basic data for developing processed 'Dodamssal' rice-based products.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.29 no.6
• /
• pp.327-340
• /
• 2017

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.43 no.5
• /
• pp.100-110
• /
• 2015

With the trend for the construction of barrier-free living environments in accordance with the ever-increasing external activity of the aging population, multi-culture families and socially disadvantaged, there is also a demand for the facilities improvement at parks for their convenience of use. This study analyzed the possibility of Barrier-Free Certification of an existing open space and defined its prototype renovation plan. This study is intended to help develop Borame Park into a barrier-free park by securing a barrier-free line of movement linking the major facilities sites within the park, improving park facilities lest there should be inconvenience in the use of the major facilities, and a guidance system convenient for use by physically and mentally impaired people. The significance of this study lies in the fact that it diagnosed the possibility of the BF Certification of existing urban parks and established a barrier-free park, which is easy for anyone to use. In the course of doing research on this, this study was able to discover the limitations of the BF Certification system, and its related tasks to be solved in the future as follows: The first thing this study shows is that there is a lack of understanding and awareness of the BF Certification system. Basically, there is a need for giving consideration to the development of a barrier-free living environment from the planning and design phase of a park, but in actuality, an examination of the certification is undertaken at the time of the completion of design and construction, which causes a large loss both time-wise and economically. Second, as evaluative items for the BF Certification of a park, applied are detailed evaluation items that fail to reflect the characteristics of an outdoor space whose natural constraints are large, such as geographical highs and lows and existing trees, plants, etc. Third, guidelines for establishment of a barrier-free park must be created in the light of the locational conditions of the park, followed by improvements of its BF Certification evaluation items.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.21 no.1
• /
• pp.24-35
• /
• 2016

To assess the relationship between environmental factors and seasonal phytoplankton community structure, we investigated abiotic and biotic factors in Ulsan Bay, Korea. We divided the bay into two areas based on geographical characteristics and compared the difference in each factor between inner and outer bay with t-test statistics. As a result, temperature in the outer bay was higher than that of the inner bay during winter (t = -5.833, p < 0.01) and autumn (p > 0.05). However, opposite trend was observed during spring (t = 4.247, p < 0.01) and summer (t = 2.876, p < 0.05). Salinity was significantly lower in the inner bay than in the outer bay in winter, spring, and summer (p < 0.01). However, the salinity was not significantly different between the inner and the outer bay in the autumn (p > 0.05). In particular, high nutrient concentration was observed in most stations during winter season due to vertical well mixing. The nutrient concentration was significantly higher in surface layers of inner bay after rainfall, particularly in the summer. The relative contribution (approximately 70%) of < $20{\mu}m$ (nano and pico) size phytoplankton was increased in all seasons with continuously low nutrients from the offshore water due to their adaption to low nutrient without other large competitors. Interestingly, high population of Eutreptiella gymnastica was kept in the inner bay during the spring and summer associated with high DIN (nitrate+nitrite, ammonium) after river discharge following rainfall, suggesting that DIN supply might have triggered the increase of Eutreptiella gymnastica population. In addition, high density of freshwater species Oscillatoria sp. and Microcystis sp. were found in several stations of the inner bay that were provided with large amounts of freshwater from the Tae-wha River. Diatom and cryptophyta species were found to be dominant species in the autumn and winter. Of these, centric diatom Chaetoceros genus was occupied in the outer bay in the autumn. Cryptophyta species known as opportunistic micro-algae were found to have high biomass without competitors in the inner bay. Our results demonstrated that Ulsan Bay was strongly affected by freshwater from Tae-wha River during the rainy season and by the surface warm water current from the offshore of the bay during dry season. These two external factors might play important roles in regulating the seasonal phytoplankton community structures.