• Journal of the Korean earth science society
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• v.34 no.6
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• pp.561-574
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• 2013

This study investigates energy fluxes measured near Gangjeong-Goryeong Weir of the Nakdong River of South Korea for more than a year, from July 2011 to September 2012, in order to analyze the applicability of the data for future impact analyses. Each of the two study sites is located in a rural area, surrounded by agricultural fields, and an urban industrial area. Sensible and latent heat fluxes are analyzed according to the wind direction. In the summertime, when the wind blows from the river, sensible heat tends to decrease and latent heat tends to increase at both sites. This result is considered to be caused by moisture transfer from the river. Bowen ratio, energy balance closure, momentum flux, and stability are analyzed as well. The Bowen ratio of the rural agricultural site turns out higher than that of the urban site regardless of the season. The energy balance closure is higher at the agricultural site compared to the urban area, which is mainly due to exclusion of the storage term calculation at the urban site. The momentum flux is greater at the urban site both in winter and summer. The instability lasts longer during daytime and in the summertime, when there is a strong turbulence. The data from these sites are appropriate to be used in analyzing the impact of river in surrounding areas for future studies.

• Journal of the Korean Society of Food Culture
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• v.27 no.6
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• pp.588-597
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• 2012

This study was to examine Kwa-Jung-ryu, a traditional Korean confectionery, made by head families. We examined the materials and recipes of Kwa-Jung-ryu, which were classified into Yumilgwa, Yugwa, Jeonggwa, Dasikgwa, Yeot-Gangjeong, Dang (Yeot), and others. There were 13 head families that introduced Kwa-Jung-ryu, two each from Gyeonggi-do, Jeolla-do, and Chuncheong-do, and seven from Gyeongsang-do. There are 33 types of Kwa-Jung-ryu, which averages to about 2.5 types per family. But the Pungsan Ryu, Yeoju Lee, and Andong Kwon families introduced the most Kwa-Jung-ryu with 5 types each. The most popular types of Kwa-Jung-ryu were Yumilgwa, introduced by 7 families (Yakgwa by 6 and Maejakgwa by 1), then Jeonggwa by 6 families (Jeonggwa by 3, Pyeon-gang by 1, and Jeonggwa and Pyeon-gang by 2), and Dasikgwa and other Kwa-Jung-ryu by 5 families (Gotgam-mari by 4 and Seopsansam by 1). Classifying Kwa-Jung-ryu by recipe, the most frequently introduced were 8 types of Jeonggwa-ryu, 7 types of Yumilgwa, 5 types of Dasikgwa, 3 types of Yeot-Gangjeong and Dang (Yeot), and 2 types of Yugwa.

• Journal of Wetlands Research
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• v.19 no.2
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• pp.181-192
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• 2017

Analysis using a numerical model is important to understand the sediment transport mechanism associated with erosion and sedimentation near weirs and other hydraulic structures within riverine systems. The local riverbed change near a hydraulic structure (Gangjeong-Goryong multi-function weir in the Nakdong river) was analyzed in order to examine the effect of hydraulic structures on local bed change. A 2D numerical model (CCHE-2D) was employed to simulate the sedimentation and erosion over a reach (25 km) including the weir. For the calibration and verification of the model, rainfall data from a real event (Typoon 'Ewiniar' in 2006) were used for flow and stage simulation. And the simulated results show a good agreement with the observed data for the whole domain. From the result, it was found that the installation and operation of the weir could aggravate bed changes by typhoon between movable weirs, and which resulted in redistribution of sediment.

• Journal of Environmental Science International
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• v.27 no.7
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• pp.477-488
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• 2018

In this study, heavy metal levels at the sediment monitoring network site upstream of the Gangjeong-Goryeong weir in the Nakdong River were surveyed from 2012 to 2016. We assessed the sediment pollution level using various pollution indexes based on ICP-MS analysis. The stream sediment pollution assessment standard, established through Regulation No. 687 of the National Institute of Environmental Research (2015), pollution load index (PLI), potential ecological risk index (RI), and mean PEL Quotient (mPELQ) were used to evaluate the sediment pollution level. We verified the representativeness of the monitoring point through the distribution of sedimentation and scour behavior by river bed surveying using anacousticDopplercurrentprofiler.

• Journal of the Korean Society of Food Culture
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• v.36 no.5
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• pp.502-511
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• 2021

In this study, the content of water-soluble vitamins such as vitamin B₁ (thiamin), B₂ (riboflavin), B₃ (niacin), B₅ (pantothenic acid), B₆ (pyridoxine), B₇ (biotin), B₁₂ (cyanocobalamin), and C (ascorbic acid) in dishes containing meat and seafood consumed in Korea were determined by high-performance liquid chromatography (HPLC) with ultraviolet and fluorescence detection. All analyses were performed under strict quality control of vitamins B₁, B₂, B₃, B₅, B₆, B₇, B₁₂, and C. The highest content of vitamin B₁ was observed in Bugeo-gangjeong (1.373 mg/100 g) and the highest level of vitamin B₂ (5.162 mg/100 g) was found in pig liver. Bugeo-gangjeong showed the highest content of vitamin B₃ (21.676 mg/100 g), and kkomak-muchim contained considerable amounts (43.310 mg/100 g) of vitamin B₅. Vitamin B₆ was not detected in most seafood dishes except for yangnyeom myeongran-jeot (0.274 mg/100 g) and was present at low levels or not present at all in meat dishes. The highest content of vitamin B₇ was 6.506 ㎍/100 g in saeu-jeon and kkomak-muchim showed the highest content (21.132 ㎍/100 g) of vitamin B₁₂. The highest content of vitamin C was in yangnyeom myeongran-jeot (84.508 mg/100 g). In addition, the analysis methods of each water-soluble vitamin were verified. These results showed that seafood-based ingredients in several dishes could be a good source of water-soluble vitamins.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.299-305
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• 2013

This study surveyed the real state of children-favored food sold within the green food zone in Gwangju and whether they were high calorie and low nutrition food (HCLNF) or not. A total of 124 samples, which were kimbab (8), tteokbokki (7), toast (12), and Mandu (8) in meal and fried (potato, 6), fried (etc, 6), sundae (7), chicken (skewed, 7), chicken (gangjeong, 5), hot dog (7), corn dog (7), oden (7), slush (27), and oden soup (10) in between meal, were surveyed. The test items are moisture, ash, crude fat and protein, carbohydrate, free sugars, sodium, and saturated fat. In 35 samples of four meal categories, every samples had sodium more than the criteria (600 mg per serving size) and had saturated fat lower than the criteria (4 g per serving size) except twelve toasts. All of toasts were identified as HCLNF due to saturated fat and sodium contents. Four toasts also exceeded the calorie criteria (500 Kcal per serving size). In 89 samples of ten between meal categories, every samples had protein more than the criteria (2 g serving size) excepting slushes and had free sugars lower than the criteria (17 g per serving size) excepting one chicken (gangjeong). Most of fried foods, chickens (gangjeong), and corn dogs had saturated fat more than the criteria (4 g per serving size). But only five fried foods and five chickens (gangjeong) were identified as HCLNF due to calorie (500 Kcal per serving size). In 27 samples of slushes, 20 samples had free sugars more than the criteria (17 g per serving size) with no protein, so they all were identified as HCLNF.

• Journal of Environmental Impact Assessment
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• v.24 no.3
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• pp.278-286
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• 2015

Pilot scale system was designed to identify the growth and movement of algae, depending on environmental changes(retention time, nutrient concentration, etc) in Gangjeong-Goryeong Weir of the Nakdong River. Considering the stability of algal culture and easy observation of algal growth, pilot scale system was made of transparent acrylic material(3 sets of flexible cylindrical water tanks with 1 m diameter and 4 m height). Auxiliary equipments include light intercepter, water inflow device for different water depth and storage of reclaimed water. The retention time was 2 days(before construction of weir; treatment 1), 8 days(after construction of weir, 2013; treatment 2) and 30 days(2014; treatment 3). According to the water temperature of treatment 1 were similar by depth, treatment 3 showed a difference between the surface(0 m) and bottom(4 m) more than $3^{\circ}C$. DO, pH showed relatively high in the surface than the bottom. Nutrients showed eutrophic condition in all experiments. The Chlrophyll-a concentration of the treatment 1 showed a relatively lower value than the Chlrophyll-a concentration of the treatment 2 and 3. Therefore, the retention time was considered to influence the growth of phytoplankton.

• Journal of Environmental Impact Assessment
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• v.28 no.3
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• pp.245-262
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• 2019

The objectives of this study were to construct a three-dimensional water quality model (EFDC) for the river reach between Chilgok Weir and Gangjeong-Goryong Weir (GGW) located in Nakdong River, and evaluate the effect of hydraulic changes, such as water level and flow velocity, on the control of water quality and algae biomass. After calibration, the model accurately simulated the temporal changes of the upper and lower water temperatures that collected every 10 minutes, and appropriately reproduced changes in organic matter, nitrogen, phosphorus, and cyanobacteria. However, the simulated values were overestimated for the diatoms and green algae cell density, possibly due to the uncertainties of the parameters associated with algae metabolism and the lack of zooplankton predation function in the simulations. As a result of scenario simulation of running the water level of GGW from EL. 19.44 m to EL. 14.90 m (4.54 m drop), Chl-a and algae cell density decreased significantly.In particular,the cyanobacteria on the surface layer, which causes algal bloom, declined by 56.1% in the low water level scenario compared to the existing management level. The results of this study are in agreement with the previous studies that maintenance of critical flow velocity is effective for controlling cyanobacteria, and imply that hydraulic control such as decrease of water level and residence time in GGW is an alternative to limit the overgrowth of algae.

• Journal of Environmental Science International
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• v.24 no.12
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• pp.1649-1656
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• 2015

Jeju Island is the highest rain-prone area in Korea that possesses affluent water resources, but future climate changes are predicted to further increase vulnerabilities as resultant of increasing of extreme events and creating spatial-temporal imbalance in water resources. Therefore, this study aimed to provide basic information to establish a proper water resources management plan by evaluating the effects of climate change on water resources using climate change scenario. Direct runoff ratio for 15 years (2000~2014) was analyzed to be 11~32% (average of 23%), and average direct runoff ratio for the next 86 years (2015~2100) was found as 28%, showing an increase of about 22% compared to the present average direct runoff ratio (23%). To assess the effects of climate change on long-term runoff, monthly runoff variation of future Gangjeong watershed was analyzed by dividing three time periods as follows: Present (2000~2030), Future 1 (2031~2070) and Future 2 (2071~2100). The estimated results showed that average monthly runoff increases in the future and the highest runoff is shown by Future 2. Extreme values has been expected to occur more frequently in the future as compared to the present.

• Journal of Power System Engineering
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• v.20 no.4
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• pp.44-51
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• 2016

An investigation on reliability of reanalysis wind data was conducted using the met mast wind data at four coastal regions, Jeju Island. Shinchang, Handong, Udo and Gangjeong sites were chosen for the met mast sites, and ERA-Interim and MERRA reanalysis data at two points on the sea around Jeju Island were analyzed for creating Wind Statistics of WindPRO software. Reliability of reanalysis wind data was assessed by comparing the statistics from the met mast wind data with those from Wind Statistics of WindPRO software. The relative error was calculated for annual average wind speed, wind power density and annual energy production. In addition, Weibull wind speed distribution and monthly energy production were analyzed in detail. As a result, ERA-Interim reanalysis data was more suitable for wind resource assessment than MERRA reanalysis data.