• Journal of the East Asian Society of Dietary Life
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• v.13 no.4
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• pp.284-292
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• 2003

This study was conducted to investigate the changes of dietary attitudes and behaviors in relation to the use of computers of elementary school children in Seoul. The total of 451 elementary school children, consisting of 235 females and 216 males, participated in the study. The result of domestic characteristics, dietary attitudes and behaviors, the level of the use of computers, and health-related symptoms of the subjects were achieved through the questionnaires as follows: The average height, weight, BMI and obesity-index of the participants were 149.0 cm, 42.4 kg, 19.0, -8.6, respectively. Anions subjects, 42.8％ answered their bed times were between 11~12 pm, and 82.4％ answered that they had extracurricular activities. The most desired activity as their leisure was computer works (female: 44.3％, male: 62.5％). 38.4％ of children used the computers for 1~2 hours a day and the most general usage of computers was a computer game (66.1％). The changes in dietary habits of the subjects were such as eating faster(30.2％), having lots of snacks(28.8％), eating anything at hand(26.4％), skipping breakfast due to over-sleeping(18.4％). As changes in life patterns, those in the time managements for watching T.V.(35.3％), reading(35.0％), exercising(31.9％), sleeping(27.5％), relaxing(27.5％) and other hobbies(26.4％) were observed. In conclusion, many children were being affected by the socioeconomic factors changing the environments, especially by the need for the use of computers. The rates of eating alone and skipping breakfast were getting higher in the dietary patterns of elementary school children. We found that the changes in social environments according to the heavy use of the computer were affecting on their dietary pattern. The direction and method of nutrition education had to be established for the proper understanding of the desirable dietary behaviors.

• Journal of the Speleological Society of Korea
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• no.72
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• pp.19-30
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• 2006

The purpose of this study is to clarified the geology and geomorphic characteristics of the Hantan River Basin. In this area, some kind of landforms are developed such as pre-land forms, lava plateau, and present landforms etc. Some river terraces are peculiar features in the area. Some conclusions are as follows : The vicinity of the Hantan River is lava plateau formed from the volcanic activity. Some steptoes are located in the lava plateau. Baekeuiri formation means the river bed boulder beneath the lava formation. The development of drainage patterns are unstable and the bifurcation ratio, the ratio of mean length of the river are lower than the other rivers. The relative height of the terraces is about $5{\sim}25m$ and the terraces are alluvial terraces. In the Jiktang Fall area, bedrock is granite and basalt plateau covered the bedrock. In that point, the old erosion surface is relatively steeper than the horizontal-basalt plateau. Vertical columnar joints are developed and weathering materials creep on the valley wall. The cross section of the landform of the Kosukjung vicinities are somewhat different from the landforms of Jiktang Fall. The bedrock near the Kosukjung is granite that is the same with the Jiktang Fall. But the cross section shows a asymmetrical curve from each side.

• Korean Chemical Engineering Research
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• v.45 no.3
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• pp.277-285
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• 2007

The adsorption characteristics of multi-component solvent vapors including poorly-adsorbable chemicals such as toluene-xylene-MEK and toluene-MEK-IPA on the activated carbonaceous adsorbents were investigated in a stainless steel fixed bed of 10.2 cm ID and 50 cm in height in order to identify those carbons for eliminating and recovering solvent vapors from industrial emission sources. The used activated carbonaceous adsorbents were pelletized commercial activated carbons and activated carbon fiber. Breakthrough curves and adsorption capacity at atmospheric pressures were obtained. It has been found that non-polar and larger molecules have been adsorbed better than polar and smaller molecules. In special, alcohols and ketones were poorly adsorbed caused by competitive adsorbability in multi-component mixture system. However, it could be overcome by profitable employment of organization of cooperative system which was composed of different porosity activated carbonaceous adsorbents appropriately.

• Journal of the Korean Institute of Rural Architecture
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• v.14 no.2
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• pp.1-10
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• 2012

The purpose of this study is to provide the method of saving the construction cost per unit area of the New Hanok using the inner space of a roof as a floor space with a structural modification of it's roof. The proportion of a roof of the Traditional Hanok accounts for about a half of it's elevation, so it is an essential element of it. But, compare to the whole construction cost of the Traditional Hanok, it costs over a half of expenses to build it. Recently, at the traditional building type, it is found that the inner space of a roof of it is used as a floor space with a structural modification of it's roof. It can be divided into two types, the storage type and the living type. The New Hanok at downtown can accommodate various new lifestyle, so the length of it's Yangtong is longer than that of the Traditional Hanok. When we adjust the proportion of the traditional Hanok to the New Hanok, the height of the column and the roof of the New Hanok becomes also higher than those of the traditional Hanok. So, using the upper part of the column and the roof of the New Hanok, we can make the inner space of a roof of the New Hanok as a floor space -like a bed room, tea room, personal work space and a storage- vertically connect with the 1st floor as the main living area. As a result, it is expected to save the unit construction cost of the New Hanok and has an extensity of space when we build the New Hanok at downtown.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.1
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• pp.33-38
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• 2003

Turbidity meter calibrations were conducted using bottom sediment and suspended material collected with a vertical array of sediment traps at the coastal water off Gaduk Island. Compared to the bottom sediment comprising sand fraction of approximately 6％, trapped suspended material was composed entirely of silt and clay fractions and showed a tendency to get finer as elevation from the sea-bed increases. Slope parameter of linear regression due to bottom sediment was of minimum value and values of those due to suspended material increased gradually as the height of sediment trap increases (i.e., sediment size decreases). This result shows that turbidity meter calibration using bottom sediment can cause an overestimation error in the calculation of suspended sediment concentration and that the error can reach up to 25% in case of this study. Therefore, it is suggested that the use of a corrected calibration curve based on grain size distribution of suspended material instead of bottom sediment may reduce the measurement error of suspended sediment concentration.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.499-504
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• 2009

Erythrosine is used a food coloring, ink and dye, etc. but erithrosine is rarely used in United States due to its known hazards. The adsorption characteristics of erythrosine by granular activated carbon were investigated in the batch adsorber and the packed column. The adsorptivity of activated carbon for erythrosine were largely improved by pH control. When the pH was 11 in the sample, the erythrosine could be removed 98% of initial concentration. It was estabilished that the adsorption equilibrium of erythrosine on granular activated carbon was successfully fitted by Freundlich isotherm equation in the concentration range from 10mg/L to 1,000mg/L. The characteristics of breakthrough curve of activated carbon packed column depend on the design variables such as initial concentration, bed height, and flow rate.

• Journal of Biosystems Engineering
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• v.35 no.6
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• pp.373-379
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• 2010

This study was carried out to develop a belt pick-up type one-row soybean cutter, using physical properties and production conditions of soybeans. The prototype soybean cutter consisted of 4 parts: cutting part, conveying part, collecting part, and travelling part. The prototype soybean cutter was designed to cut soybeans planted with a row spacing of 600 mm, and at a height of 30 mm from the bed bottom using a disk saw. Through various trials with different peripheral velocities of the disk saw and forward speed of the cutter, determined ranges of the peripheral velocity of the disk saw cutting soybeans stems were greater than 18.3 m/s. Spacing between pick-up belts (clearance) was in a range of 60~90 mm so that soybeans could be picked at heights greater than 25 cm, and the size and shape of the pick-up belt were determined the conventional manual harvesting method. The optimal ratio between the forward speed of cutter and the peripheral speed of pick-up belts were from 1 to 1.2 by theoretical analysis. the pick-up belts had a $35^{\circ}$ of tilted angle and $90^{\circ}$ of twisted angle to pick up soybeans safely from the plant input to the lower end of the belts and convey soybeans to the upper end of belts nearby a container. The soybeans at the rear container were dropped down on the soybean row with an interval. The effective field capacity of the prototype soybean cutter was 0.136 ha/h, reducing the working hour by 92% when compared with the manual cutting.

• Korean Journal of Plant Resources
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• v.14 no.3
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• pp.241-246
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• 2001

Effects of cutting media on shooting and seedling characteristics were investigated to determine productivity of seedling by root cuttings of lacquer tree. Shoots developed at 3 weeks after cut planting on PV (peat moss : Vermiculite : 1 : 1), PVS (peat moss : Vermiculite : Sand : 1 : 1 : 2) and PVSC (peat moss : Vermiculite : Sand : Clay loam : 1 : 1 : 2 : 2) media, and shooting rate was the highest in PVSC medium at 10 weeks after cut planting among the treatments. Shooting numbers per scion on PH and PVC media were 2.2 but those on HSC medium was 1.3, which was not significantly different among media. PVSC medium was suitable to use the root cuttings of lacquer tree as it meets the qualifications requirements. Seedlings on PVSC medium were excellent to transplant in field as tree height, branch number, leaf number, stem diameter and leaf area were good.

• Journal of Korean Society of Disaster and Security
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• v.11 no.2
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• pp.83-89
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• 2018

The significant sedimentation at the estuary in the eastern coast of Korea frequently causes river mouth occlusion where disconnection between the river and sea is observed. River mouth occlusion causing watershed retention raises the environmental risk of the area as it impairs water quality and threatens the area's safety in the event of floods. This study proposes a plan to maintain stability of river channel and flow of flood discharge at the estuary with loss of its function for disaster prevention. To this end, the study tries to change the location and width of stream path, focusing on the center line of stream near the sand bar of river mouth. This allows to identify a shape of stream path that leads the most stable flow. To review the result, this study uses the SRH-2D, a model for two-dimensional hydraulic analysis, and conduct numeric simulation. The simulation result showed that the most effective plan for maintaining the stable flow of running water without having the area sensitive to changes in hydraulic characteristics is to lower the overall river bed height of the sand bar near the center line of stream to a equal level.

• Clean Technology
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• v.16 no.3
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• pp.206-212
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• 2010

The adsorption characteristics of quinoline yellow by granular activated carbon were investigated experimently in the batch adsorber and packed column. The adsorptivity of activated carbon for quinoline yellow were largely improved by acidic pH and higher temperature. When the pH was 3 at $60^{\circ}C$, quinoline yellowcould be removed 97 percent of initial concentration(10 mg/L). It was estabilished that the adsorption equilibrium of quinoline yellow on granular activated carbon was successfully fitted by Freundlich isotherm equation in the temperature range from $25^{\circ}C$ to $60^{\circ}C$. The estimated values of k and ${\beta}$ are 38.71~166.60, 0.380~0.490, respectively. The breakthrough curve of activated carbon-packed column depends on the design variables such as initial concentration, bed height, and flow rate.