• Kyungpook Mathematical Journal
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• 제54권4호
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• pp.521-529
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• 2014

In this paper we derive some optimal convex combination bounds related to arithmetic mean. We find the greatest values ${\alpha}_1$ and ${\alpha}_2$ and the least values ${\beta}_1$ and ${\beta}_2$ such that the double inequalities $${\alpha}_1T(a,b)+(1-{\alpha}_1)H(a,b)<A(a,b)<{\beta}_1T(a,b)+(1-{\beta}_1)H(a,b)$$ and $${\alpha}_2T(a,b)+(1-{\alpha}_2)G(a,b)<A(a,b)<{\beta}_2T(a,b)+(1-{\beta}_2)G(a,b)$$ holds for all a,b > 0 with $a{\neq}b$. Here T(a,b), H(a,b), A(a,b) and G(a,b) denote the second Seiffert, harmonic, arithmetic and geometric means of two positive numbers a and b, respectively.

• 대한화장품학회지
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• 제50권1호
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• pp.77-84
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• 2024

사용 연령이 만 4 세 이상부터 표시된 어린이 화장품세트 4 건을 온라인으로 구매하였으며 각 구성품 81 건을 대상으로 납, 카드뮴, 비소, 안티몬, 니켈, 코발트, 구리, 크롬 및 수은의 함량을 inductive coupled plasma-mass spectrometry (ICP - MS)로 분석하였다. 어린이 화장품의 중금속 평균값은 납 0.82 ㎍/g, 카드뮴 0.03 ㎍/g, 비소 0.97 ㎍/g, 안티몬 0.52 ㎍/g, 니켈 2.32 ㎍/g, 수은 0.01 ㎍/g으로 모든 제품에서 허용 기준보다 낮았다. 국산과 수입산의 비교 결과, 국산보다는 수입산에서 납, 안티몬, 코발트, 구리의 평균값이 높게 검출되었다(p < 0.05). 화장품 유형에 따른 중금속 평균값은 통계적으로 유의한 차이를 보였는데(p < 0.05) 아이새도에서 비소 2.47 ㎍/g, 니켈 6.36 ㎍/g, 크롬 11.06 ㎍/g으로 평균값이 가장 높게 나왔으며, 볼연지에서 납 1.20 ㎍/g, 안티몬 1.17 ㎍/g, 구리 23.60 ㎍/g으로 가장 높게 나왔다. 분석된 81 건의 어린이 화장품에 대한 코발트의 검출 수준은 불검출 ~ 5.23 ㎍/g, 구리는 불검출 ~ 379.61 ㎍/g, 크롬은 불검출 ~ 36.95 ㎍/g이었다. 브라운 색상의 화장품은 니켈과 코발트에서 평균값이 높게 검출되었으며, 퍼플 색상은 납과 크롬에서 높게 검출되었다.

• 한국수자원학회논문집
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• 제42권8호
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• pp.659-671
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• 2009

본 연구에서는 레이더 강우량 자료의 편차보정에 사용되는 G/R비의 정확도를 향상시키기 위하여 fuzzy c-means 방법을 사용한 자료의 군집화를 적용하였다. 대상 레이더자료는 광덕산 레이더기지의 자료로서 유효범위 100km이내의 자료를 대상으로 지상관측망인 기상청의 AWS(Automatic Weather System) 지점에서 관측한 자료와의 비교를 통하여 G/R비를 구하였다. G/R비를 구하는데 있어서 전체 유효범위를 대상으로 동일한 방법을 사용한 경우와 레이더 자료의 군집화를 통해서 지형적인 효과를 고려한 경우를 비교하였으며, AWS 실측강우량과 G/R비를 통한 레이더 강우량 자료의 비교를 위하여 절대상대오차와 평균제곱근오차 등을 비교분석하였다. 그 결과 전체유효범위를 대상으로 동일하게 G/R비를 적용하여 구한 레이더 강우량에 비하여 군집분석을 이용하여 지형효과를 고려한 G/R비를 적용한 레이더 강우량의 오차가 더 적게 나타났다.

• Molecular & Cellular Toxicology
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• 제4권3호
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• pp.235-245
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• 2008

Exposure to mercury was assessed in 125 Korean (Gwangju and Busan) and 373 Chinese primary school students (Xinguang village, Goumen town) using hair mercury analysis from November 2006 to September 2007. The geometric mean concentration of mercury was higher among Korean children with recording 0.73 ${\mu}g$/g, compared to Chinese children of 0.12 ${\mu}g$/g, which indicated statistically difference (P<0.01). The mean concentration of Korean children living near incineration facilities was higher by recording 0.76 ${\mu}g$/g while the average concentration of their counterpart in Korea reached 0.69 ${\mu}g$/g. In case of Chinese children, those who are living near power plants showed higher level with posting 0.16 ${\mu}g$/g while the others recorded 0.10 ${\mu}g$/g (P<0.01). Intake of fish was found to be related to hair mercury level. In case of Korean children, those with high fish intake recorded 0.79 ${\mu}g$/g in terms of the geometric mean concentration while the others with low fish intake posted 0.61 ${\mu}g$/g. Among Chinese children, those who often eat fish recorded 0.13 ${\mu}g$/g compared to the others with low fish intake of 0.11 ${\mu}g$/g. On the other hand, amalgam dental fillings have limited influence on mean hair mercury level. As for vaccination, within a month of vaccination, the geometric mean concentration of Korean children reached 0.76 ${\mu}g$/g, and in case of 15 days after injection, the level was 1.20 ${\mu}g$/g. In China, the level of children at one month after receiving injection stood at 0.15 ${\mu}g$/g while the level within 15 days was 0.13 ${\mu}g$/g. Multiple regression analysis showed that BMI, passive smoking, and fish consumption are closely related to hair mercury level among the Korean subjects. In China, hair mercury level was affected by age, location, passive smoking, fish consumption, and vaccination. Explanatory power was 21.6% with $R^2$=0.216.

• 한국자원식물학회지
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• 제23권1호
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• pp.1-6
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• 2010

농촌진흥청 국립농업유전자원센터로부터 국내외에서 수집된 해바라기 328종을 분양받아 바이오디젤 가능 작물로서 특성을 조사한 바 그 결과는 다음과 같다. 해바라기 수집종의 출아소요일수는 7~12일이었으며, 개화 소요일수는 55~86일로 폭넓게 분포하였다. 수집종 해바라기의 경장은 평균이 259 cm로 그 분포는 131~345 cm의 변이를 보였고, 성숙일수는 평균 35일이었다. 주당 두화수(頭花數)는 1개~23개로 큰 변이를 보였으며, 두화의 크기는 평균 17.6 cm 로 14.7~21.3 cm가 72.8%로 가장 높게 분포하였다. 두화당 종자수는 평균 1,430개 정도, 종실중은 평균 91.4 g로 28~379 g로 넓은 분포를 보였다. 종실길이는 평균 11.7 mm, 범위는 9.0~21.5 mm 이었으며, 종실 폭은 평균 6.4 mm, $1\;{\ell}$ 무게는 평균 322.5 g이었으며, 천립중은 평균 63.3 g, 주당 종실중은 평균 204 g이었다. 생육 및 종실 특성 중에서 두화 당 종자수의 변이가 가장 컸고, 다음으로 주당종실 중의 변이가 컸다. 수집종들의 형질 간 상관분석 결과, 경장이 클수록 종실폭은 커지고 개화일수도 길어졌으나, 성숙일수와 생육일수는 짧았다.

• 한국수산과학회지
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• 제51권6호
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• pp.667-672
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• 2018

We investigated the quality of 12 commercial salted and fermented anchovy Engraulis japonicas sauces by measuring their chemical compositions, bacteria concentrations, and biogenic amine contents. The sauces had a moisture content of 67.13-69.83% (mean: 68.17%), salinity of 20.00-25.84% (mean: 22.29%), pH of 5.14-6.28 (mean: 5.63), volatile basic nitrogen content of 119.12-273.37 mg/100 g (mean: 199.19 mg/100 g), total nitrogen content of 0.82-1.50% (mean: 1.30%) and amino nitrogen content of 550.17-1,086.62 mg/100 g (mean: 774.99 mg/100 g). The viable cell counts ranged from not detected to $1.6{\times}10^3CFU/mL$, and the number of biogenic amine-forming bacteria was very low or undetectable. The tested samples contained 372.32-2,111,61 mg/kg (mean 813.48 mg/kg) histamine, 29.62-144.29 mg/kg (mean 98.14 mg/kg) cadaverine, 87.89-530.84 mg/kg (mean 329.91 mg/kg) tryptamine, 20.89-127.17 mg/kg (mean 60.49 mg/kg) putrescine, and 13.08-109.91 mg/kg (mean 57.74 mg/kg) tyramine. Whereas no spermidine or spermine was detected in any sample. These results strongly suggest the necessary of monitoring the biogenic amine contents of commercial salted and fermented anchovy sauces carefully to ensure consumer health.

• Tuberculosis and Respiratory Diseases
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• 제78권2호
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• pp.78-84
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• 2015

Background: Reports of therapeutic drug monitoring (TDM) for second-line medications to treat multidrug-resistant tuberculosis (MDR-TB) remain limited. Methods: A retrospective cohort from the Virginia state tuberculosis (TB) registry, 2009-2014, was analyzed for TDM usage in MDR-TB. Drug concentrations, measured at time of estimated peak ($C_{max}$), were compared to expected ranges. Results: Of 10 patients with MDR-TB, 8 (80%) had TDM for at least one drug (maximum 6 drugs). Second-line drugs tested were cycloserine in seven patients (mean $C_{2hr}$, $16.6{\pm}10.2{\mu}g/mL$; 4 [57%] below expected range); moxifloxacin in five (mean $C_{2hr}$, $3.2{\pm}1.5{\mu}g/mL$; 1 [20%] below); capreomycin in five (mean $C_{2hr}$, $21.5{\pm}14.0{\mu}g/mL$; 3 [60%] below); para-aminosalicylic acid in five (mean $C_{6hr}$, $65.0{\pm}29.1{\mu}g/mL$; all within or above); linezolid in three (mean $C_{2hr}$, $11.4{\pm}4.1{\mu}g/mL$, 1 [33%] below); amikacin in two (mean $C_{2hr}$, $35.3{\pm}3.7{\mu}g/mL$; 1 [50%] below); ethionamide in one ($C_{2hr}$, $1.49{\mu}g/mL$, within expected). Two patients died: a 38-year-old woman with human immunodeficiency virus/acquired immune deficiency syndrome and TB meningitis without TDM, and a 76-year-old man with fluoroquinolone-resistant (pre-extensively drug-resistant) pulmonary TB and low linezolid and capreomycin concentrations. Conclusion: Individual pharmacokinetic variability was common. A more standardized approach to TDM for MDR-TB may limit over-testing and maximize therapeutic gain.

• 한국산업보건학회지
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• 제25권4호
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• pp.493-505
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• 2015

Objectives: The purpose of this study was to evaluate the relevance of adjusting a urinary sample for urine hippuric correction value and its effects. Urinary biological monitoring data are typically adjusted to a constant creatinine and specific gravity concentration to correct for variable dilutions among spot samples. This study was conducted to evaluate the suitability of adjusting the urinary concentrations of urine creatinine and specific gravity(SG). Methods: We measured the concentrations of hippuric acid, in spot urine samples collected from control(119), case(120) individuals. The value of hippuric acid was adjusted by SG and urinary creatinine(HPLC & Jaffe). Results: The major results were as follows. The concentrations of urinary creatinine and SG for the control group were 1.84 g/L(SD 0.99) for arithmetic mean and 1.56 g/L(GSD 1.86) for geometric mean by HPLC method, 1.57 g/L (SD, 0.82) for arithmetic mean and 1.33 g/L(GSD 1.85) for geometric mean by Jaffe method, 1.028(SD 0.09) for arithmetic mean and 1.02(GSD 1.06) for geometric mean by refractometer. Hippuric acid levels were 0.40 g/L(SD 0.51) by arithmetic mean and 0.20 g/L(GSD 3.59). In that case the exposed group was 1.40 g/L(SD 0.58) for arithmetic mean and 1.28 g/L(GSD 1.55) for geometric mean by HPLC method, 1.27 g/L(SD 0.56) for arithmetic mean and 1.14 g/L(GSD 1.62) for geometric mean by Jaffe method, 1.045 L(SD 0.27) for arithmetic mean and 1.02(GSD 1.13) for geometric mean by refractometer(P<0.05). Hippuric acid levels were 0.67 g/L(SD 0.79) for arithmetic mean and 0.39 g/L(GSD 2.94)(p<0.05). The urine creatinine concentrations were affected by gender(p < 0.01) but SG levels were not affected by gender or age(p>0.05). After adjustment, urine hippuric acid was correlated with creatinine(HPLC & Jaffe)(r=0.723, P<0.05, r=0.708, P<0.05) and SG(r=0.936, P<0.05) and the control group shows significantly higher than the case group. In the case group for adjusted urine hippuric acid was correlated with creatinine(HPLC & Jaffe), (r=0.736, P<0.05), r=0.549, P<0.05), SG(r=0.549, P<0.05). After adjusting urine hippuric acid by urine creatinine(HPLC and Jaffe method) and specific gravity, significant associations were found between the control group and case group, respectively(r=0.832, P<0.05, r=0.845, P<0.05) and (r=0.841, P<0.05, r=0.849, P<0.05). Specific gravity adjustment appears to be more appropriate for variations in the urine creatinine method. Conclusion: we found that urinary creatinine concentrations were significantly affected by gender, and other factors and that care should therefore be exercised when correcting urinary metabolites according to the urinary creatinine concentration in spot urine. It is determined that additional study is needed for biological monitoring.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.1137-1140
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• 2005

We present the discrete-time version of the heuristic interpretation of the mean waiting time known well about the continuous-time version. The heuristic approach is mainly based on an arriving customer's viewpoint. We obtain the mean waiting time of $Geo^X/G/1$ queueing systems, including vacation queues.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1111-1115
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• 2006

We present heuristic interpretations of the mean waiting time of $Geo^X/G/1$ vacation queues with set-up time. The heuristic interpretation of the mean waiting time is originally proposed for the continuous-time queues. We demonstrate that the heuristic approach is useful for the discrete-time queues as well.