• 한국지하수토양환경학회지:지하수토양환경
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• 제25권3호
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• pp.12-22
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• 2020

Managed aquifer recharge (MAR) is a promising water management strategy for securing stable water resources to overcome water shortage and water quality deterioration caused by global environmental changes. A MAR demonstration site was selected at Imgok-ri, Sangju-si, Korea, based on screening for the frequency of drought events and local water supply situations. The abundant groundwater discharging from a nearby abandoned coal mine is one of the potential recharge water sources for the MAR implementation. However, it has elevated levels of arsenic (~12 ㎍/L). In this study, the potential of the natural attenuation of arsenic by the field geological media was investigated using batch and column experiments. The adsorption and desorption parameters were obtained for two drill core samples (GM1; 21.8~22.8 m and GM2; 26.0~27.8 m depth) recovered from the potentially water-conducting fracture-zones in the injection well. The effluent arsenic concentrations were monitored during the continuous flow of the mine drainage water through the columns packed with the core samples. GM2 removed about 60% of arsenic in the influent (0.1 mg-As/L) while GM1 removed about 20%. The results suggest that natural attenuation is an acitive process occurring during the MAR operation, potentially lowering the arsenic level in the mine drainage water below the regulatory standard for drinking water. This study hence demonstrates that using the mine drainage water as the recharge water source is a viable option at the MAR demonstration site.

• 대한지역사회영양학회지
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• 제18권4호
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• pp.354-364
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• 2013

This study was conducted to determine whether dietary factors could be related with serum adiponectin concentrations in 243, year-three female university students living in Seoul. The mean of body mass index (BMI) and adiponectin levels of all subjects were $20.17kg/m^2$ and $11.07{\mu}g/ml$, respectively. When the subjects were divided into 3 groups based on BMI (underweight: < 18.5, normal: $18.5{\leq}&lt;23$, overweight and obesity: ${\geq}23$), serum adiponectin levels in underweight group was significantly higher than that in 'normal' or 'overweight and 'obesity' groups. Also when the subjects were divided into two groups by mean adequacy ratio (MAR), serum adiponectin concentration of the high MAR group (MAR > 75) was slightly higher than that the low MAR group ($MAR{\leq}75$). Serum adiponectin levels showed a negative correlation with body weight (p < 0.01) or BMI (p < 0.001) and a positive correlation with intakes of of animal or total protein (please clarify) or vegetable protein.Among the dietary behaviors, serum adiponectin levels of females who answered 'yes' to the question about 'eating breakfast' was significantly higher than that of those who answered 'sometimes' or 'No' (p < 0.05) and serum adiponectin levels were higher among those who reported higher fruit intakes. Overall, our results suggested that healthy lifestyle including acceptable BMI, eating breakfast and higher fruit consumption might play an important role in the prevention of obesity and enhancement of blood adiponectin levels.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1337-1358
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• 2015

In this paper, we present an analytical and simulated study on the performance of adaptive vehicular ad hoc networks (VANET) priority based on Transmission Distance Reliability Range (TDRR) and data type. VANET topology changes rapidly due to its inherent nature of high mobility nodes and unpredictable environments. Therefore, nodes in VANET must be able to adapt to the ever changing environment and optimize parameters to enhance performance. However, there is a lack of adaptability in the current VANET scheme. Existing VANET IEEE802.11p's Enhanced Distributed Channel Access; EDCA assigns priority solely based on data type. In this paper, we propose a new priority scheme which utilizes Markov model to perform TDRR prediction and assign priorities based on the proposed Markov TDRR Prediction with Enhanced Priority VANET Scheme (MarPVS). Subsequently, we performed an analytical study on MarPVS performance modeling. In particular, considering five different priority levels defined in MarPVS, we derived the probability of successful transmission, the number of low priority messages in back off process and concurrent low priority transmission. Finally, the results are used to derive the average transmission delay for data types defined in MarPVS. Numerical results are provided along with simulation results which confirm the accuracy of the proposed analysis. Simulation results demonstrate that the proposed MarPVS results in lower transmission latency and higher packet success rate in comparison with the default IEEE802.11p scheme and greedy scheduler scheme.

• Journal of Nutrition and Health
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• 제37권2호
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• pp.132-142
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• 2004

Nutritional factors affecting bone mineral density (BMD) in the different age groups of Korean men were investigated to obtain baseline data for maintaining bone health. Information on diet and anthropometry was collected in 80 elementary school children, 83 high school students, 87 adults aged 25 to 35 years and 98 elderly people over 60 years of age. Data for food and nutrient intake were obtained by 24-hour recall method. BMDs of lumbar spine (L$_2$- L$_4$) and femoral neck were measured by dual energy x-ray absorptiometry. The relationship between BMD and nutritional factors were analyzed. In the femoral neck, 5.7% of adults was classified as osteopenia and 47.9% and 37.8% of the elderly were classified as osteopenia and osteoporosis. It was shown that plant protein, Ca, p, Fe, thiamin, riboflavin and vitamin C intakes were related with BMD in all age groups. As for the mean adequacy ratio (MAR) of nutrients, the lowest quartile group of BMD showed significantly lower MAR among children. The RDA percent of nutrients was a strong influential factor on BMD. Subjects who consumed below 75% of Korean RDA in energy, vitamin A, thiamin, and vitamin C showed lower BMD. Stepwise multiple regression analysis revealed that MAR in children, vegetable Ca in adolescents, and vitamin C in adults and elderly people were the highest influential factor on BMD. Therefore, the above results demonstrated that not only calcium but also other nutrients such as protein, iron, vitamin A, riboflavin, and vitamin C were necessary in order to keep the healthy bone status. In addition, although there were various dietary factors that influenced bone density, MAR was identified as the major factor that affected bone density. Thus, a balanced diet that includes all nutrients is necessary for a healthy bone density. (Korean J Nutrition 37(2) : 132-142, 2004)

• Nutritional Sciences
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• 제7권2호
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• pp.92-97
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• 2004

Despite the universal recommendation to eat a variety of foods, we still do not know whether and to what extent the variety affects dietary quality. This study was performed to evaluate the dietary variety scores as tools for assessing the dietary quality of Korean young adults. The 1-day dietary intake data were collected from 144 male and 214 female college students (>18 years) using the 24-hour recall method Relative nutrient intake compared to Korean Recommended Dietary Allowance (KRDA) as the nutrient adequacy ratio (NAR), were computed Also, the mean adequacy ratio (MAR) was calculated. Dietary variety score (DVS) was determined by counting the number of food items consumed daily, and the dietary diversity score (DDS) by counting the number of food groups consumed daily. Results showed that DVS, DDS and MAR were significantly correlated to each other. The MAR score significantly increased as DDS increased in both men and women. When different DVS (20$\leqDVS\leq$ 30) was evaluated for its sensitivity, specificity, measured prevalence, true prevalence, and positive and negative predictive values towards MAR, DVS 21 was revealed to be optimal dietary variety score as a cutoff point to differentiate Korean young adults with or without an adequate and balanced diet. Nutrient intakes of subjects who had DVS<21 were significantly lower than those of subjects with DVS$\qeq$ 21. These results indicate that the dietary variety score appeared to be an effective tool for evaluating the adequacy of diet in Korean young adults.

• 한국수산과학회지
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• 제49권2호
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• pp.116-123
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• 2016

This study investigated the prevalence of Vibrio parahaemolyticus in the oyster Crassostrea gigas, which is commonly consumed raw. The presence of virulence factors and the antimicrobial susceptibility of isolates were also investigated. The overall prevalence rate of V. parahaemolyticus in oysters was 37.5% (36/96) and the range of concentrations was 30-11,000 MPN/100 g. PCR-based assays indicated that 9.6% (11/115) of the isolates were positive for the thermostable direct hemolysin-related hemolysin gene (trh), while none of the isolates were positive for the thermostable direct hemolysin gene (tdh). The Multiple Antibiotics Resistance (MAR) index was measured for 16 common antimicrobial agents and 46.1% (53/115) of the isolates had a MAR index > 0.2. The MAR index ranged from 0.07 to 0.73. The highest MAR index was observed with strain s150608, isolated in June 2015, which exhibited resistance to 11 antimicrobial agents. Our results demonstrate that oysters are high-risk sources of V. parahaemolyticus, although no antimicrobial agent was being used to promote growth or to treat bacterial infections in the sampled oyster-growing areas.

• Journal of the korean society of oceanography
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• 제35권2호
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• pp.98-108
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• 2000

A geochemical study on a hemipelagic core sediment taken from the northwest Pacific Ocean (eastern edge of the Shikoku Basin) was conducted to use of excess barium (Ba(ex)) for evaluate the paleoceano-graphic changes. Also, the excursion of sedimentary Ba(ex) was compared with those of biogenic opal, carbonate and organic carbon content in the sediment during the last glacial and interglacial periods. The calculated Ba(ex) derived from the major and minor element shows a distinctive glacial-interglacial variations, and the mass accumulation rate (MAR) of Ba(ex) shows coincident variations with the MARs of biogenic fractions. Especially, strong positive correlation (r$^2$=0.85) between the MAR of Ba(ex) and the MAR of biogenic carbonate is recognized. Based on the strong positive correlation(r$^2$=0.85) between the MAR of Ba(ex) and the MAR of carbonate content, we estimated the degree of carbonate dissolution rate during the glacial and interglacial periods. Assuming the proportional variation and the refractory nature of barium exist between two factors, the variation of index Ca/Ba ratio in sediment indicates the degree of carbonate dissolution. Sedimentary Ca/Ba ratios index clearly show a striking fluctuation between the glacial and interglacial periods with higher positive correlation during glacial and lower correlation during interglacial. This fact indicates enhanced carbonate dissolution during interglacial period. Thus, the sedimentary Ca/Ba ratio in sedimentary records can be used as one of the useful tools for estimation of the relative degree of carbonate dissolution. The excursion of Ba(ex) and the sedimentary Ca/Ba ratio follows the typical pacific carbonate dissolution type(enhanced dissolution during interglacial and reduced dissolution during glacial time) as suggested by previous work (e.g., Wu et al., 1990). Variation in sedimentary Ca/Ba ratio thus strongly supports that glacial-interglacial fluctuation in carbonate dissolution has been prevailed in the northwest Pacific Ocean.

• Advances in materials Research
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• 제2권3호
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• pp.141-153
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• 2013

Nanocrystalline Barium niobate ($BaNbO_3$) has been synthesized by a novel auto-igniting combustion technique. The X-Ray diffraction studies reveals that $BaNbO_3$ posses a cubic structure with lattice constant $a=4.071{\AA}$. Phase purity and structure of the nano powder are further examined using Fourier-Transform Infrared and Raman spectroscopy. The average particle size of the as prepared nano particles from the Transmission Electron Microscopy is 20 nm. The UV-Vis absorption spectra of the samples are recorded and the calculated average optical band gap is 3.74eV. The sample is sintered at an optimized temperature of $1425^{\circ}C$ for 2h and attained nearly 98% of the theoretical density. The morphology of the sintered pellet is studied with Scanning Electron Microscopy. The dielectric constant and loss factor of a well-sintered $BaNbO_3$ at 5MHz sample is found to be 32.92 and $8.09{\times}10^{-4}$ respectively, at room temperature. The temperature coefficient of dielectric constant was $-179pp/^{\circ}C$. The high dielectric constant, low loss and negative temperature coefficient of dielectric constant makes it a potential candidate for temperature sensitive dielectric applications.

• 한국양식학회지
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• 제11권4호
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• pp.457-463
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• 1998

미꾸라지(Misgrunus mizolepis)의 DNA로부터 클론된 핵기질 부착부위(MAR)를 포함하는 발현벡터인 pUC19N6-luc 벡터를 구성하였다. 이를 물고기 CHSE-214 세포주에 electroporation으로 transfection 시킨 후 유전자의 발현율, 벡터의 copy 수 및 염색체내 삽입 양상을 luciferase 활성도 분석, PCR 및 Southern blotting를 통해 분석하였다. 대조군 발현벡터에 luciferase 유전자는 전형적인 transient 발현양상을 나타내는데 비해, 미꾸라지 MAR가 포함된 pUC19N6-luc 벡터의 luciferase 유전자의 발현은 transfection 후 5일째부터 급격히 증가하는 양상을 보였다. Transfection된 CHSE-214 세포내에서 pUC19N6-luc 벡터는 대조군 벡터에 비해 높은 copy 수를 유지하였으나, 염색체내 삽입은 거의 비슷한 시간에 일어났다. 결론적으로 transfection 후 시간경과에 따른 pUC19N6-luc 벡터내의 luciferase 유전자의 발현 증가에 미치는 MAR의 효과는 벡터 copy수 증가 때문이 아니라, 염색체내 삽입후 형성되는 전사활성구조의 형성에 기인하는 것으로 판단된다.

• 대한지역사회영양학회지
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• 제8권1호
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• pp.102-111
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• 2003

The purpose of this study was to investigate the relationship among serum leptin, nutritional status, and the obesity indices of 55 obese children in Daegu and Kyungpook area. Obesity was defined as fat percentage that exceed 25% of body fat mass. Energy and nutritional status were tended to be low, and dietary intake of calcium and iron were less than any other nutrients in all the subjects. Especially, beverage intake of obese group was more than non-obese group. The leptin level were significantly correlated with %RDA of energy (0.41, p < 0.001), protein (0.44, p < 0.001), phosphate (0.40, p < 0.001), iron (0.37, p < 0.001), vitamin A (0.31, p < 0.01), thiamin (0.40, p < 0.001), riboflavin (0.26, p < 0.05), niacin (0.51, p < 0.001), and vitamin C (0.24, p < 0.05). The leptin level were significantly correlated with MAR (mean adequacy ratio, r : 0.43, p <0.001) and INQ (index of nutrient quality) of thiamin (r : 0.22, p <0.05). Multiple regression analysis showed that %RDA of niacin in obese group ($R^2$: 0.208, p : 0.001) and total subjects ($R^2$ : 0.257, p : 0.000), MAR (p : 0.003) and INQ (p : 0.048) of niacin in obese group ($R^2$ : 0.255) and MAR (p : 0.000) and rNQ ofca (p : 0.024) in total subjects ($R^2$ : 0.231) may be important independent predictors to leptin level. MAR showed a significantly positive correlation with %fat (r = 0.42, p < 0.01), BMI (r = 0.46, p < 0.01), RW (r : 0.44, p < 0.01), WHR (r : 0.39, p < 0.01) and, "ieRnA (p < 0.05, p < 0.01). These data indicated relationships among leptin level, nutrient intake, %RDA, MAh, and INQ in children.dren.