• Communications of the Korean Mathematical Society
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• v.28 no.2
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• pp.231-241
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• 2013

On the framework of the 2-adic group $\mathcal{Z}_2$, we study a Sobolev-like inequality where we estimate the $L^2$ norm by a geometric mean of the BV norm and the $\dot{B}_{\infty}^{-1,{\infty}}$ norm. We first show, using the special topological properties of the $p$-adic groups, that the set of functions of bounded variations BV can be identified to the Besov space ˙$\dot{B}_1^{1,{\infty}}$. This identification lead us to the construction of a counterexample to the improved Sobolev inequality.

• Journal of the Korean Mathematical Society
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• v.41 no.1
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• pp.157-174
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• 2004

In this work we discuss "plank problems" for complex Banach spaces and in particular for the classical $L^{p}(\mu)$ spaces. In the case $1\;{\leq}\;p\;{\leq}\;2$ we obtain optimal results and for finite dimensional complex Banach spaces, in a special case, we have improved an early result by K. Ball [3]. By using these results, in some cases we are able to find best possible lower bounds for the norms of homogeneous polynomials which are products of linear forms. In particular, we give an estimate in the case of a real Hilbert space which seems to be a difficult problem. We have also obtained some results on the so-called n-th (linear) polarization constant of a Banach space which is an isometric property of the space. Finally, known polynomial inequalities have been derived as simple consequences of various results related to plank problems.

• Journal of the Korean Geotechnical Society
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• v.35 no.12
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• pp.15-24
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• 2019

Weathered granite zone exists in most regions of Korea and it is often used as a bearing stratum of geotechnical structures. So it is very important to estimate the characteristics of weathered granite zone. SPT (Standard penetration test) is usually performed to investigate the characteristics of the weathered zone because undisturbed samples suitable for laboratory testing are hardly retrieved. PMT (Pressuremeter test) can reliably evaluate the in situ stress-strain behavior, but it is rarely conducted because of their high cost and time-consuming procedure. In this study, the correlation between the SPT-N values and the PMT results, obtained from the weathered granite zone, was analyzed. Empirical equations for pressuremeter modulus (E_m) and limit pressure (P_L) were suggested and compared with the previous research.

• Nutrition Research and Practice
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• v.1 no.2
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• pp.120-125
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• 2007

Folate is important for multiple metabolic processes such as nucleic acid synthesis and interconversions, and cell division. Folate deficiency may be a risk factor for several pathologies, such as neural tube birth defects, dementia, and cardiovascular diseases. The objectives of this study were to estimate folate intakes and plasma concentrations of young children living in Kwangju, Korea. Three consecutive 24-h food recalls and fasting blood samples were obtained from 24 boys and 30 girls, aged 2-6 y, living in Kwangju, Korea. The daily folate intake ($mean{\pm}SD$) of the children was $146.7{\pm}73.6{\mu}g$ dietary folate equivalents. No differences in folate intakes were observed by gender ($p{\geq}0.05$). The mean folate intakes of the 2 and 3 y old groups were significantly lower (p<0.05) than those of 5 and 6 y old groups. Over half of subjects consumed $mean{\pm}SD$) of all subjects was $19.2{\pm}8.7nmol/L$, and there was no significant difference by age nor gender ($p{\geq}0.05$). No significant correlation was observed between folate intakes and plasma folate concentrations. One subjeci (1.9%) in this study had a plasma folate concentration <6.8 nmol/L, which is indicative of folate deficiency. Approximately 24% of subjects had plasma folate concentrations of 6.8-13.4 nmol/L, which is representative of marginal folate status. In conclusion, some young children may have less than adequate folate status in Korea.

• Korean Journal of Community Nutrition
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• v.26 no.5
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• pp.350-362
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• 2021

Objectives: This study investigated an association between sugar-sweetened beverage (SSB) intake and the dietary quality of adults in Deagu, Korea. Methods: A questionnaire survey was conducted in 1,022 adults aged 19 ~ 49 years (502 men and 520 women) in the Deagu area of Korea. Daily intake of SSB was obtained by the food frequency questionnaire, and the dietary quality was assessed using the nutrition quotient (NQ) for Korean adults. Multiple logistic regression analysis was used to estimate the association between dietary quality and daily intake of SSB in adults. Results: Daily intake of SSB was 463.6 mL/d for total subjects, and the highest intakes were sweetened coffees (192.7 mL/d), followed by carbonated drinks (77.1 mL/d). Higher intake of SSB was associated with higher intake frequency of fast food or sweet and greasy bread, processed beverage, ramyon, eating out or delivery food and night snack, and also associated with lower frequency of water, breakfast intake and nutrition label checking in men or women. Men and women who had a higher intake SSB had significantly greater odds for being in the low grade of NQ (P for trend = 0.0006 for men, P for trend = 0.0007 for women), especially in the moderation factor (P for trend < 0.0001 for men and women). Conclusions: This study showed that high SSB intake was significantly associated with low dietary quality among adults. These study results suggest that nutrition education programs and guidelines should be provided to adults for improving their consumption of SSB and related diets.

• Preventive Nutrition and Food Science
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• v.17 no.1
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• pp.53-63
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• 2012

This study was conducted to develop an optimal composite recipe for pan bread with ramie powder that has high sensory approval with all age groups and to estimate the DPPH radical scavenging activity and the pan bread shelf life after gamma irradiation. The sensory evaluation results showed significant differences in flavor (p<0.05), appearance (p<0.01), color (p<0.01), moistness (p<0.01), and overall quality (p<0.05) based on the amount of ramie powder added. As a result, the optimum formulations by numerical and graphical methods were calculated to be as follows: ramie powder 2.76 g (0.92%) and water 184.7 mL. Optimized pan bread with ramie powder and white pan bread were irradiated with gamma-rays at doses of 0, 10, 15, and 20 kGy. The total bacterial growth increased with the longer storage time and the least amount of ramie powder added. Consequently, these results suggest that the addition of ramie powder to pan bread provides added value to the bread in terms of increased shelf life.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.400-408
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• 2017

This experiment was conducted to estimate the livestock carrying capacity per unit area of Hanwoo heifer with determine the quality of the forage by evaluating the productivity and nutritive value of spring seeding oats (Avena sative L.) according to different seeding and harvesting timings. Dry matter yields were the highest at 13.62 tons per ha when oat was seeded on March 15 and harvested on June 8 (p < 0.05), while the lowest yield of 6.29 tons per ha was obtained when seeded on February 25 and harvested on May 19 (p < 0.05). The highest crude protein yield of 1.27 tons per ha (p < 0.05) was obtained when seeded on March 5 and harvested on June 8. The total digestible nutrient yield was the highest at 7.38 tons per ha when harvested on June 8, the last harvest of the experiment (p < 0.05). In the northern part of Gyeongbuk province, spring seeding oats at the beginning of March, rather than in the middle of March, showed good annual livestock carrying capacity per unit area. According to harvest timing, the plot harvested on June 8 showed the highest livestock carrying capacity with an average of 6.53 heads (p < 0.05). In conclusion, in the northern part of Gyeongbuk province in spring, it is better to seed oat early in March and to harvest early in June to increase the livestock breeding capacity, considering dry matter productivity and feed value.

• Korean Journal of Environment and Ecology
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• v.27 no.4
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• pp.498-506
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• 2013

In order to identify soil characteristics and to estimate the age of wetland, soil samples of Mt. Sohwangbyoung wetland and Jilmoi wetland known as peatland in Odaesan National Park.were collected and analyzed. Soil pH of Mt. Sohwangbyoung wetland and Jilmoi wetland showed average pH of 5.5, and did now show any significant difference according to the time and plant community. Total ionic content of soil showed different values among plant communities, but no difference by time in each plant community. Soil exchangeable cations such as Na, K and Mg showed a similar pattern of total ionic content. Unlike other cations, however, Ca content showed significant differences according to the plant community and time. Soil organic matter and total nitrogen contents showed remarkable differences according to plant community, and especially showed very low valeus at the place where Sphagnum palustre distributes. Based on the results of the above, Mt. Sohwangbyoung wetland and Jilmoi wetland can be considered as weakly acidic bog. From age analysis, two wetlands are estimated to have been formed before 100 AD for Mt. Sohwangbyoung wetland and 1448 AD for Jilmoi wetland, respectively.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.573-580
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• 2017

Precise stochastic modeling for GPS measurements is one of key factors in adjustment computations for GPS positioning. To analyze the GPS measurement errors, Minimum Norm Quadratic Unbiased Estimators(MINQUE) approach is used in this study to estimate the variance components for measurement types with short-baseline GPS positioning model. The results showed the magnitudes of measurement errors for C1, P2, L1, L2 are 22.3cm, 27.6cm, 2.5mm, 2.2mm, respectively. To reduce the memory usage and computational burden, variance components are also estimated on epoch-by-epoch basis. The results showed that there exists slight differences between the solutions. However, epoch-by-epoch analysis may also be used for most of GPS applications considering the magnitudes of the differences.

• Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.8.1-8.11
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• 2016

To quantitatively estimate the influence of cuttlebone on the target strength (TS) of golden cuttlefish, the cuttlebone was carefully extracted from 19 live cuttlefish caught using traps in the inshore waters around Geojedo, Korea, in early May 2010 and the TS was measured using split-beam echosounders (Simrad ES60 and EY500). The TS-length relationships for the cuttlefish (before the extraction of cuttlebone, Fish Aquat Sci. 17:361-7, 2014) and the corresponding cuttlebone were compared. The cuttlebone length ($L_b$) ranged from 151 to 195 mm (mean $L_b$ = 168.3 mm) and the mass ($W_b$) ranged from 29.3 to 53.2 g (mean $W_b$ = 38.8 g). The mean TS values at 70 and 120 kHz were -33.60 dB (std = 1.12 dB) and -32.24 dB (std = 1.87 dB), respectively. The mean TS values of cuttlebone were 0.19 dB and 0.04 dB lower than those of cuttlefish at 70 and 120 kHz, respectively. For 70 and 120 kHz combined, the mean TS value of cuttlebone was -32.87 dB, 0.11 dB lower than that of cuttlefish (-32.76 dB). On the other hand, the mean TS value of cuttlebone predicted by the regression ($TS_b$ = 24.86 $log_{10}$ $L_b$ - 4.86 $log_{10}$ ${\lambda}$ - 22.58, $r^2$ = 0.85, N = 38, P < 0.01) was -33.10 dB, 0.04 dB lower than that of cuttlefish predicted by the regression ($TS_c$ = 24.62 $log_{10}$ $L_c$ - 4.62 $log_{10}$ ${\lambda}$ - 22.64, $r^2$ = 0.85, N = 38, P < 0.01). That is, the contribution of cuttlebone to the cuttlefish TS determined by the measured results was slightly greater than that by the predicted results. These results suggest that cuttlebone is responsible for the TS of cuttlefish, and the contribution is estimated to be at least 99 % of the total echo strength.