• Korean Journal of Legislative Studies
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• v.24 no.1
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• pp.135-170
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• 2018

The recent success of populist parties and candidates in the US and European countries leads to a massive amount of empirical research on populism, a deviant form of representative democracy. Much ink has been spilled to define populism and to identify the causes of its rise and continued success in democratic political system. However, little is known about populist attitudes of individual voters. Using a large-scale online survey fielded in the context of the South Korean presidential election in 2017, this study examines (1) what determines populist attitudes of South Korean voters and (2) how populist attitudes are associated with evaluations of political parties, candidates, and political issues. Statistical analysis reveals that people high on populism are more likely to support an underdog left-wing political party and its presidential candidate, and are less likely to support policies implemented or proposed under the auspices of the Park Geun-hye administration. These findings do not necessarily suggest the inherent affinity between populism and left-wing ideology; rather, it implies populist attitudes happened to appear in 2017, in reactions to lack of confidence in the previous government.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.277-284
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• 2021

This study surveyed the ecological characteristics of Squalidus gracilis majimae at Nakdong River tributary Sinan Stream from January to December 2020. The species inhabited the riverbed that was mostly covered with gravel and sand. The water depth was 27-158 cm, and the average was rather deep at 54 cm. The stream velocity was slow at 0.41±0.19 (0.24-0.86) m/sec. The gender ratio of females to males was 1:0.73. According to the total length-frequency distribution, the age indicated that the group with less than 50 mm in total length was one year old, the group with 70-69 mm was two years old, and the group over 70 mm was three years old. The total length of sexually mature fishes was 50 mm for females and 60 mm for males. The spawning season was from June to July, and the water temperature was 20.9-23.4℃ during the period. The prosperous spawning season was July. The average number of eggs in the ovaries was 1,009 (595-1,630) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 0.78±0.08 (0.57-0.83) mm. The live foods were S. gracilis majimae Protozoa, attached algae, zooplankton, and aquatic insects. The feeding habits of S. gracilis majimae are omnivorous, but more than 80% of the stomach content was aquatic insects, Chironomidae spp. The larger the size of this species, the greater the amount and frequency of eating aquatic insects, which are animal feeds. The population that ate aquatic insects did not eat vegetable food.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.601-608
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• 2021

This study surveyed the ecological characteristics of Squalidus multimacultus at Taehwa River tributary Cheokgwa Stream from January to December 2020. The species inhabited the riverbed that was mostly covered with sand. The water depth was 25-164 cm, and the average was rather deep at 68 cm. The stream velocity was slow at 0.21±0.26 (0.16-0.43) m/sec. The gender ratio of females to males was 1:0.99. The age according to the total length-frequency distribution indicated that the group with less than 50 mm (29.4 - 49 mm) in total length was one year old, the group with 50 - 69 mm was two years old, the group with 70 - 89 mm was three years old, and the group over 90 mm was four years old. The total length of sexually mature fishes was 40 mm for both males and females. The spawning season was from July to August, and the water temperatures was 23.8 - 25.4℃ during the period. The prosperous spawning season was August. The average number of eggs in the ovaries was 1,395 (648 - 2,201) per matured female, and the matured eggs were yellowish and spherical with a mean diameter of 0.67±0.24 (0.62 - 0.83) mm. The live foods were of S. multimacultus attached algae, zooplankton, aquatic insects, and Mollusca. The feeding habits of S. multimacultus were omnivorous, but more than 95% of the stomach content was plant-attached algae. The larger the size of this species, the greater the amount and frequency of eating aquatic insects, which were animal feeds. The population that ate aquatic insects did not eat vegetable food.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.381-389
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• 2022

This study investigated the ecological characteristics of Microphysogobio yaluensis at Dugye Stream of Geum River basin from January to December 2021. The river bed structure of this species' habitat was rich in pebbles and gravel. The water depth ranged from 12 to 85 cm with an average of 23 cm, which was shallow. The stream velocity was rapid at 1.03±0.34(0.72-1.47) m/sec. The ratio of females to males was 1:0.86. The age according to the total length-frequency distribution as of summer (June, July) indicated that the group with less than 50 mm (30.4-49 mm) in total length was one year old, the group with 50-69 mm was two years old, and the group over 70-92 mm was three years old. Both male and female fish sexually matured at 50 mm long and two years old in June and July. The spawning season was from July to August, and the water temperature was between 25.8℃ and 28.2℃ during the period. The prosperous spawning season was July. The matured eggs were yellowish and spherical with a mean diameter of 0.52±0.16 (0.33-0.77) mm, and the average number of eggs found in the ovaries of mature female fish was 2,593 (1,343-4,672). As for the food of M. yaluensis, only attached algae, which grow by attaching to stones and gravel of the stream rapids, were identified. The feeding habit of M. yaluensis was reported to be herbivorous, ingesting Cyanophyta, Chlorophyta and Bacillariophya. Also, the species belonging to Bacillariophya and Chlorophyta were abundant in Dugye Stream.

• Journal of The Geomorphological Association of Korea
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• v.27 no.1
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• pp.1-19
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• 2020

A river bed which is submerged in water at high flow and becomes part of the river at low flow, serves as a bridge between the river and the land. The channel bar creates a unique ecosystem with vegetation adapted to the particular environment and the water pool forms a wetland that plays a very important role in the environment. To evaluate anthropogenic impacts on the river bed in the Middle Yeongsangang River, the fluvial landforms in the stream channel were analyzed using multi-temporal remotely-sensed images. In the aerial photograph of 2005 taken before the construction of the large weirs, oxbow lakes, mid-channel bars, point bars, and natural wetlands between the artificial levees were identified. Multiple bars divided the flow of stream water to cause the braided pattern in a particular section. After the construction of the Seungchon weir, aerial photographs of 2013 and 2015 revealed that most of the fluvial landforms disappeared due to the dredging of its riverbed and water level control(maintenance at 7.5El.m). Sentinel-2 images were analyzed to identify differences between before and after the opening of weir gate. Change detection was performed with the near infrared and shortwave infrared spectral bands to effectively distinguish water surfaces from land. As a result, water surface area of the main stream of the Yeongsangang River decreased by 40% from 1.144km² to 0.692km². A large mid-channel bar that has been deposited upstream of the weir was exposed during low water levels, which shows the obvious influence of weir on the river bed. Newly formed unvegetated point bars that were deposited on the inside of a meander bend were identified from the remotely sensed images. As the maintenance period of the weir gate opening was extended, various habitats were created by creating pools and riffles around the channel bars. Considering the ecological and hydrological functions of the river bed, it is expected that the increase in bar areas through weir gate opening will reduce the artificial interference effect of the weir.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.837-841
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• 2004

Changes in total aerobic bacteria (TAB), lactic acid bacteria (LAB), rod- and coccal-shaped lactic acid bacteria (R- and C-LAB), pH, and total acidity were investigated during fermentation of radish with new fermentation base at $20^{\circ}C$ for up to 16 days. New fermentation base was prepared by pre-fermenting a mixture of rice bran and rice water (1 : 0.1, w/v) at $20^{\circ}C$ for 7 days. Initially, radish showed 5.41, 4.23, 4.57, and 3.1 log CFU/g, and base showed 6.68, 6.60, 5.95, and 5.6 log CFU/mL for TAB, LAB, R-LAB, and C-LAB, respectively. Initial pH and total acidity of radish were $6.6^{\circ}C$ and 0.09%, and those of base were 5.76 and 0.36%, respectively, Counts of LAB (4.23 to 8.33 Bog Cpu/g, 6.6 to 9.7 log CFU/mL), R-LAB (4.57 to 7.15 log CFU/g, 5.95 to 8.5 log CFU/mL), and C-LAB (3.1 to 7.5 log CFU/g, 5.6 to 8.6 log CFU/mL) of radish and base respectively increased during initial fermentation period, then remained constant during late fermentation period, and far 4 days after fermentation, pH values (6.6 to 4.19, 5.76 to 4.57) drastically decreased and thereafter slowly decreased. Total acidities of radish and base (0.09 to 0.63%, 0.36 to 0.63%, respectively) drastically increased far 7 days after fermentation and increased slightly thereafter.

• Korean Journal of Environment and Ecology
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• v.33 no.5
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• pp.515-524
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• 2019

The purpose of this study is to investigate the effects of artificial disturbance by analyzing and comparing the survey data of the Yeongju dam located in Yeongju-si, Gyeongbuk before and after impoundment. We surveyed four sites between the downstream of sediment control to the downstream of Yeongju Dam four times between April and October 2018. The macroinvertebrate data before the survey were gathered from the literature. The total number of benthic macroinvertebrates we observed was $35,037ind./m^2$, including 77 species, 48 families, 14 orders, 7 classes, and 3 phyla. The result of the community analysis showed that the dominant index increased from 0.44(${\pm}0.11$) before impoundment to 0.62(${\pm}0.16$) after impoundment. The diversity index increased from 2.26(${\pm}0.30$) to 1.75(${\pm}0.45$), the evenness index from 0.75(${\pm}0.10$) to 0.66(${\pm}0.14$), and the richness index from 3.11(${\pm}0.98$) to 2.25(${\pm}0.81$). The most dominant species changed from Hydropsychidae spp. to Chironomidae sp. The result of the Principal Components Analysis (PCA) based on Axis 1 showed that the sites of 2014 and Hydropsychidae spp. had a negative value, while the sites of 2018 and Chironomidae sp. had a positive value. In all study sites, the dominance increased while the diversity decreased. The community change was the largest in St. 2. The results of the functional group analysis showed that the scrapers increased while gathering-collectors increased among the functional feeding group and that the clingers decreased while borrows increased among the habitat oriented group. The Benthic Macroinvertebrate Streambed Index (BMSI) decreased from an average of 57.1(${\pm}8.0$, C class) to an average of 30.0(${\pm}12.1$, C class). St. 3 and St. 4, in particular, showed a high reduction rate.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1306-1313
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• 2011

A liquid fertilizer treated with slurry composting and biofiltration (SCB) process has been applied increasingly on agricultural field but the effects on the soil properties and crop production has not been throughly evaluated. This study was conducted to investigate the effect of the SCB application on soil chemical properties and the growth of radish and corn. SCB liquid fertilizer as a basal fertilization was treated with five levels based on $6kg\;10a^{-1}$ for radish and $10kg\;10a^{-1}$ for corn. The experimental design was the completely randomized block design with five levels and three replicates. Electrical conductivity (EC), $NO_3$-N, Exch. K and Exch. Na increased depending on the treatment levels of SCB. There were no changes in soil organic matter, Avail. $P_2O_5$, Exch. Ca and Exch. Mg. EC, $NO_3$-N and Exch. Na content decreased as precipitation increased. Especially, they decreased up to the initial condition before the treatment after the heavy rainy season in 2008. Although Exch. K decreased at the rainy season, they remained relatively higher content after the experiment on August, 2008. Fresh weight and the amount of N uptake of radish increased due to the levels of SCB, but corn did not present any significant increase. It is recommended that we need to decide the proper amount of SCB as well as the application method on the field to increase the productivity and decrease environmental stress. Additional experiments also need to clarify the effect of the trace element and heavy metal accumulations due to long term application of SCB.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.1
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• pp.21-28
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• 2009

Detailed information on soil characteristics is of great importance for the use and conservation of soil resources that are essential for human welfare and ecosystem sustainability. This paper introduces soil inventory of Korea focusing on national soil database establishment, information systems, use, and future direction for natural resources management. Different scales of soil maps surveyed and soil test data collected by RDA (Rural Development Administration) were computerized to construct digital soil maps and database. Soil chemical properties and heavy metal concentrations in agricultural soils including vulnerable agricultural soils were investigated regularly at fixed sampling points. Internet-based information systems for soil and agro-environmental resources were developed based on 'National Soil Survey Projects' for managing soil resources and for providing soil information to the public, and 'Agroenvironmental Change Monitoring Project' to monitor spatial and temporal changes of agricultural environment will be opened soon. Soils data has a great potential of further application in estimation of soil carbon storage, water capacity, and soil loss. Digital mapping of soil and environment using state-of-the-art and emerging technologies with a pedometrics concept will lead to future direction.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.2
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• pp.47-56
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• 2008

The objective of this research is to evaluate the optimum recycling methods for the sewage sludge cakes at different microwave power-settings and for different periods of time. The dehydrated sewage sludge cakes used in this study was obtained from N wastewater treatment plan in the P City. The beginning drying processes were carried out in a microwave oven with 2,450 MHz frequency and power ranges of 1kW to 4 kW. The continuous conveyer drying system was also operated with 2,450 MHz frequency and power setting, ranging from of 1 kW to 6 kW. Initial moisture content of the sewage cake is 78~80%, and the moisture content decreased rapidly up to 0.2~2(wt%) within short periods due to breaking the cell walls. This study is also conducted to evaluate the characteristics of sewage sludge cakes with respect to important physical parameters effect on the thermal kinetics for evaporation water in the sludge which are operation times, moisture contents, drying rates, input amounts, flow rates and calorific values. It takes 60 minutes and 120 minutes to reach the critical moisture contents with power setting of 4 kW for 3kg/min and 6kg/min of the flow rates respectively. It takes 120 minutes and 110 minutes to reach the critical moisture contents with flow rates of 2.5 cm/min and sludge input of 6kg/min for the power settings of 4 kW and 6 kW respectively. The most effective value of the power for drying the sludge is 4 kW. Operation with 6kg/min and 4kW on 2cm of the sludge thickness can be effectively and inexpensively to reach the critical moisture contents, when you compare 2cm of the sludge thickness with 1cm and 3cm of the sludge thickness.