• Journal of Environmental Impact Assessment
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• v.24 no.1
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• pp.16-34
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• 2015

Impervious covers(IC) are artificial structures, such as driveways, sidewalks, building's roofs, and parking lots, through which water cannot infiltrate into the soil. IC is an environmental concern because the pavement materials seal the soil surface, decreasing rainwater infiltration and natural groundwater recharge, and consequently disturb the hydrological cycle in a watershed. Increase of IC in a watershed can cause more frequent flooding, higher flood peaks, groundwater drawdown, dry river, and decline of water quality and ecosystem health. There has been an increased public interest in the institutional adoption of LID(Low Impact Development) and GI(Green Infrastructure) techniques to address the adverse impact of IC. The objectives of this study were to construct the modeling site for a samll urban watershed with the Storm Water Management Model(SWMM), and to evaluate the effect of various LID techniques on the control of rainfall runoff processes and non-point pollutant load. The model was calibrated and validated using the field data collected during two flood events on July 17 and August 11, 2009, respectively, and applied to a complex area, where is consist of apartments, school, roads, park, etc. The LID techniques applied to the impervious area were decentralized rainwater management measures such as pervious cover and green roof. The results showed that the increase of perviousness land cover through LID applications decreases the runoff volume and pollutants loading during flood events. In particular, applications of pervious pavement for parking lots and sidewalk, green roof, and their combinations reduced the total volume of runoff by 15~61 % and non-point pollutant loads by TSS 22~72 %, BOD 23~71 %, COD 22~71 %, TN 15~79 %, TP 9~64 % in the study site.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.67-85
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• 2007

A three-dimensional hydrodynamic model with the fine grid is applied to simulate the barotropic tides, tidal currents, residual currents and salinity dispersions in the Yellow Sea and the East China Sea. Data inputs include seasonal hydrography, mean wind and river input, and oceanic tides. Computed tidal distributions of four major tides($M_2,\;S_2,\;K_1$ and $O_1$) are presented and results are in good agreement with the observations in the domain. The model reproduces well the tidal charts. The tidal residual current is relatively strong around west coast of Korea including the Cheju Island and southern coast of China. The current by $M_2$ has a maximum speed of 10 cm/s in the vicinity of Cheju Island with a anti-clockwise circulation in the Yellow Sea. General tendency of the current, however, is to flow eastward in the South Sea. Surface residual current simulated with $M_2$ and with $M_2+S_2+K_1+O_1$ tidal forcing shows slightly different patterns in the East China Sea. The model shows that the southerly wind reduces the southward current created by freshwater discharge. In summer during high runoff(mean discharge about $50,000\;m^3/s$ of Yangtze), low salinity plume-like structure(with S < 30.0 psu) extending some 160 km toward the northeast and Changjiang Diluted Water(CDW), below salinity 26 psu, was found within about 95 km. The offshore dispersion of the Changjiang outflow water is enhanced by the prevailing southerly wind. It is estimated that the inertia of the river discharge cannot exclusively reach the around sea of Cheju Island. It is noted that spatial and temporal distribution of salinity and the other materials are controlled by mixture of Changjiang discharge, prevailing wind, advection by flowing warm current and tidal current.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.2
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• pp.140-160
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• 2017

The purpose of this study was to develop computational thinking (CT) analysis tool that can be used to analyze CT practices; first, by defining what CT practices are, and then, by identifying which components of CT are reflected in STEAM classes. Exploring various kinds of CT practices, which can be identified while applying the proposed CT analysis tool for exemplary STEAM classes, is another goal of this study. Firstly, to answer the question of "What is CT in science education" and thereby to develop the proposed CT practice analysis tool, three types of published documents about CT definition as the main data in this study have been considered. In the first "analysis tool development" part of this study, the following five elements have been identified as the main components of CT analysis tool as follows; (1) connecting open problems with computing, (2) using tools or computers to develop computing artifact, (3) abstraction process, (4) analyzing and evaluating computing process and artifact, and (5) communicating and cooperating. Based on the understandings that there is a consistent flow among the five components due to their interactions, a flow chart of CT practice has also been developed. In the second part of this study, which is an implementation study, the proposed CT practice analysis tool has been applied in one exemplary STEAM program. To select the candidate STEAM program, four selection criteria have been identified. Then, the proposed CT practice analysis tool has been applied for the selected STEAM program to determine the degree of CT practice reflected in the program and furthermore, to suggest a way of improving the proposed CT analysis tool if it shows some weak points. Through the findings of this study, we suggest that the actual definition of computational thinking will be helpful to converge Technology and Engineering to STEAM education and a strong complement to reinforce STEAM education.

• Journal of the Korean Society of Food Culture
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• v.1 no.3
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• pp.267-278
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• 1986

The evolution of Korean fish fermentation technology was reviewed from the old literatures and the on-going processes were surveyed. The principles involved in the traditional fermentation methods were explained by the recent scientific findings. The fish fermentation technology be classified into two groups; jeot-kal process, where. salt is the only material added to the fish for fermentation, and sik-hae process, where cooked cereals, garlic and red pepper powder are added to the salted fish. A total of 46 kinds of jeot-kal was identified in a survey, depending on the raw materials used. The characteristic feature of Korean jeot-kal process is to produce fermented products which still has original shape after 2-3 months of fermentation to be used for side-dishes of rice meal, as well as fish sauce by keeping these products for longer time (over 6 months) for severe ansymematic hydrolysis to be used for the subingredient of Kimchi (Korean fermented vegetable food). The taste of jeot-kal is formed by the protein hydrolymates due to the action of salt-tolerant Pediococcus, Bacillus, Halobacterlum etc. When the taste of jeot-kal deteriorates, yeasts appear to dominate. In ski-hae fermentation, the safety of preserved fish is kept by the rapid decrease in pH resulting from the acid fermentation of added cereals. The roles of cid forming bacteria and proteloytic bacteria are important. The fermentation is completed in 2 weeks and the excess production of acid during prolonged storage limits the taste acceptability. The fish fermentation technology in Korea stands at important position in Korean food science and technology. since the processes of jeot-kal and soysauce have same root in the principle of microbial proteolysis and the processes of sik-hae and Kimchi in the microbial acid production principles.

• 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 Food Hygiene and Safety
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• v.23 no.1
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• pp.6-14
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• 2008

Objective of this study was to investigate the residual levels of mercury (Hg) in soil for "Top-rice" area and its uptake into rice plant for making sure food safety as compared to "Top-rice" & common rice produced from 2005 to 2006. Hg was analyzed with the direct mercury analyzer (DMA 80, Milestone, Italy), which implements the US/EPA method 7473. The average concentration of Hg in paddy soil was 0.031 mg/kg, which was below at 1/25-1/65 fold of the threshold levels (concern level 4 mg/kg, action level 10 mg/kg) for soil contamination designated by "The Soil Environment Conservation Law" in Korea. The maximum residue level (MRLs) for Hg residue in the polished rice is not designated in Korea. Therefore, Hg contents in the polished rice of "Top-rice" brand and common rice were compared to other country's criteria. Hg contents in the polished rice of "Top-rice" brand was 0.0018 mg/kg, which was lower at 1/10-1/30 fold than the MRLs, 0.02 mg/kg of China criteria and 0.05 mg/kg of Taiwan criteria, respectively. Hg were 0.02788, 0.00896, 0.00182, 0.00189, 0.00166, 0.00452 and 0.00145 mg/kg in soil, rice straw, unhulled rice, rice hulls, brown rice, rice bran, and polished rice produced in 2006 "Top-rice" area, respectively. For the ratio of Hg as compared to Hg contents in soil, there were 0.321 of rice straw ${\gg}$ 0.162 of rice bran ${\gg}$ 0.068 of rice hulls > 0.065 of unhulled rice > 0.060 of brown rice> 0.052 of polished rice. And, the slope of Hg uptakes was steeped as following order; rice straw ${\gg}$ rice bran ${\gg}$ rice hulls > unhulled rice > brown rice > polished rice. It means that the more slope steeped was the more uptakes. For the distribution of Hg uptaken, there was 83.8% into rice straw, and 16.2% into unhulled rice, 2.8% into rice hulls, 12.4% into brown rice, 3.5% into rice bran and 9.7% into polished rice. Consequently, it was appeared that the Hg contamination in the polished rice should not be worried in Korea.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.363-371
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• 1996

The Steering and Sailing Rules of International Regulations for Preventing Collisions at Sea now in use direct the best aid - action to avoid collision by the stand - on vessel. But these rules do not refer to the safety relative distance between two vessels when she should take such action. In this paper, the author analyzed the ship's collision avoiding actions from the viewpoint of ship motions and worked out mathematical formulas to calculate the relative distances necessary for taking action to avoid collision. Figuring out the values of maneuvering indices through experiments of 11 actual ships of small, medium, large and mammoth size, the author applied these values to the calculating formulas and calculated the minimum relative distances. The main results are as follows: 1. It was confIrmed that the stand - on vessel should keep the greatest relative distance for taking best aid - action to avoid collision when the cross angle of course was $90^{\circ}$ and near it(70-$90^{\circ}$ ). 2. When the cross angle of course was $90^{\circ}$ , the minimum relative distance of small vessel(GT: 160-650tons) was found to be more than about 6.8 times of her own length, and those of medium(GT : 2,300-3,500tons), large(GT : 22,OOO-62,OOOtons) and mammoth(GT : 91,000-139,000tons) vessels were found to be more than about 9.0 times, about 5.4 times and about 6.8 times of their own lengths. 3. It was confIrmed that collision danger was greater when crossing angle was obtuse than in an acute angle, therefore greater relative distance was to be kept by the stand - on vessel for taking best aid - action to avoid collision in the case of the obtuse angle. 4. In every vessels, in the case of $90^{\circ}$ cross angle of course the safety minimum relative distance was found to be more than about 9.0 times of their own lengths.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.7
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• pp.387-395
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• 2015

Anaerobic mesophilic batch test of several organic wastes were carried out by a graphical statistic analysis (GSA) to evaluate their ultimate biodegradability and two distinctive decay rates ($k_1$ and $k_2$) with their corresponding degradable substrate fractions ($S_1$ and $S_2$). Each 3 L batch reactor was operated for more than 100 days at the substrate to inoculum ratio (S/I) of 0.5 as an initial total volatile solids (TVS) mass basis. Their Ultimate biodegradabilities were obtained respectively as follow; 69% swine waste, 45% dairy cow manure, 66% slaughterhouse waste, 79% food waste, 87% food waste leachate, 68% primary sludge and 39% waste activated sludge. The readily biodegradable fraction of 89% ($S_1$) of Swine Waste BVS ($S_o$) degraded with in the initial 31 days with $k_1$ of $0.116day^{-1}$, where as the rest 11% slowly biodegradable fraction ($S_2$) of BVS degraded for more than 100 days with the long term batch reaction rates ($k_2$) of $0.004day^{-1}$. For the Food Waste and Waste Activated Sludge, their readily biodegradable portions ($S_1$) appeared 89% and 80%, which degrades with $k_1$ of $0.195day^{-1}$ and $0.054day^{-1}$ for an initial 15 days and 28 days, respectively. Their corresponding long term batch reaction rates ($k_2$) were $0.003day^{-1}$ and $0.002day^{-1}$. Results from other organic wastes are addressed in this paper. The theoretical hydraulic retention times (HRTs) of anaerobic digesters treating organic wastes are easily determined by the analysis of multiple decay rate coefficients ($k_1$ and $k_2$) and their corresponding biodegradable substrate fractions ($S_1$ and $S_2$).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.186-194
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• 1998

Species composition and biomass of intertidal benthic algae were studied at the coast of Yonggwang Nuclear Power Plant area and its adjacent stations over 4 seasons (October 1995-August 1996), Of 68 species identified, 7 were Cyanophyta, 12 were Chlorophyta, 14 were Phaeophyta and 35 were Rhodophyta. The largest number of algal species (44) was found at Sangnok, the northernmost station of the study area, whereas the smallest number of species (15) was found from Tongho, ca. 13 km north of the power plant site. Number of species showed highest during the spring (44) and minimum was recorded in autumn (28). Biomass per unit area showed maximum in spring ($189.5\;g\;dry\;wt{\cdot}m^{-2}$ in average) and minimum in winter ($107.9\;g\;dry\;wt{\cdot}m^{-2}$ in average). Biomass values exhibited a wide range of variation among the stations, ranging from a low of $22.0\;g\;dry\;wt{\cdot}m^{-2}$ in annual average at Tongho to a high of $295.7g\;dry\;wt{\cdot}m^{-2}$ in average at Sangnok. Dominant species in biomass were Corallina pilulifera, Sargassum thunbergii, Gymnogongrus flabelliformis and Enteromorpha compressa. There have been little variation in the dominant algal species around the power plant site during the past 10 years and also these algae appeared throughout the west coast of Korea with higher frequency.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.97-109
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• 2015

This study was focused on the placeness of Nogosan Dokjae-dong and rock inscription located in Jangheung-myeon, Yangju-si, Gyeonggi-do. The purpose was to reveal the implication of Nogosan and Dokjae-dong Valley in terms of Historic cultural landscape by considering the characteristics of the place and its landscape, and inferring the significance of the letters engraved on the rock. The result is as follows.10) Samgaksan is one of the five famous mountains in Korea. It is the sacred mountain that stands behind the capital city of the Joseon Dynasty that lasted for 600 years. On the other hand, the placeness of Nogosan is significant since it was the place where people used to bow low to the three great summits of Samgaksan. Furthermore, Nogosan was the perfect place to view Samgaksan that represented the Joseon spirit. Many letters were engraved on the rocks around Dokjae-dong Valley by Misu Heo Mok(許穆) as part of his memories to describe his experience in the mountain and became a scenery. Chusa(秋史) Kim Jung-Hee(金正喜) also engraved letters of 'Mongjae' on the rock that contains a double meaning. Literally, it means 'a dreaming house' However, it also implies that even just a daydream is significant in a way. These letters are presumed to be the signs that are related to Sung-Jae(性齋) Heo Jeon(許傳)'s experience in Dokjae-dong since the letters were part of his famous book title. Below these two letters, Chusa also engraved letters that describe the sexagenary cycle including the year of the rat, horse, dog, and tiger. They are regarded as the letters that describe the fate of Chusa's friend, a scholar born in May 1804. Nogosan and Dongjae-dong Valley are very significant in terms of historic cultural landscape as a viewpoint to see Samgaksan; and a place that cherishes the traces of Misu and shows common values and cohesiveness of well-known scholars of the Joseon Dynasty including Song Wol-Jae(松月齋) and Sung-Jae as a of Gihonamin(畿湖南人). The engraved letters of Chusa and Misu also implicitly demonstrates the major trends of Korea's calligraphy history.