• 한국환경과학회지
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• 제10권6호
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• pp.451-459
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• 2001

Adsorption characteristics of triadimefon and diniconazole(pesticide) by natural zeolite($CLI_N$) and several synthetic zeolites were Investigated. The synthetic zeolites used En this study were as follows: Faujasite synthesized from coal fly ash($FAU_F$); Zeolite synthesized from the mixture of FAU and Na-Pl synthesized from the ratio of Cheju scoria 6 to coal fly ash 4 by weight($(FAU + Na-Pl)_{SF}$); waste fluid catalytic cracking catalyst($FCC_W$). The distribution coefficient, $K_D$ and Freundlich constant, $K_F$ decreased in the fellowing sequence : $FCC_W ＞ FAU_F ＞ (FAU + Na-Pl)_{SF} ＞CLI_N$ among the zeolites. The distribution coefficient and the adsorption capacity of $(FAU + Na-Pl)_{SF}$ for pesticides were 4.4 and 2.6 times higher for triamefon, and 2.0 and 2.4 times higher for diniconazole than those of $CLI_N$, respectively.

• 한국항공우주학회지
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• 제33권1호
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• pp.62-68
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• 2005

액체로켓 가스발생기를 위한 인젝터를 설계하여 분사특성을 살펴보았다. 인젝터는 F-O-F triplet impinging이고 모의 추진제로 kerosene/물을 사용하였다. 인젝터의 형상설계 변수는 충돌각과 충돌거리이며 이를 이용하여 5가지의 후보 요소 인젝터를 설계하였으며, 모의 추진제를 사용하여 분사 특성을 실험하였다. 분사특성을 측정하기 위한 인자는 혼합효율과 분사각으로 모의 추진제 운동량비 0.2~1.3 범위에서 분사유량과 국부 O/F비를 측정하고 혼합효율을 계산하였다. 가스발생기용 인젝터는 농염한계의 O/F비 때문에 가장 높은 효율과 적절한 분사 각을 갖는 요소 인젝터를 선정하였고 연소 특성을 연구하기 위하여 연소실험을 실시하였다.

• 한국물환경학회지
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• 제23권6호
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• pp.843-849
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• 2007

Monitoring of NOM characteristics is important for improving removal efficiency of natural organic matter (NOM) in water treatment processes. In this study, several NOM characteristics, which include specific UV absorbance (SUVA), total carbonate content, molecular weight distribution, and fluorescence properties, were measured using samples collected from a pilot-scale water treatment plant consisting of coagulation/flocculation (C/F), filtration, ozonation and granular activated carbon (GAC) processes. The highest removal of NOM was observed in C/F and filtration processes as demonstrated by the reduction of dissolved organic carbon (DOC) by 25% and 21%, respectively. Despite nearly no change in DOC, however, the lowest SUVA value and the highest total carbohydrate content were observed in the sample from ozonation process. This indicates that non-degradable aromatic compounds become depleted and biodegradable organic compounds are enriched during the process. Comparison of synchronous fluorescence spectra of the samples showed that ozoation process increased protein-like fluorescence while it decreased fulvic-like and terrestrial humic-like fluorescence. Consistently, a slight peak of protein-like fluorescence was observed in the sample from ozonation process. The greatest change in molecular weight distributions of the samples was observed in C/F process. Comparison of size exclusion chromatogram of the samples revealed that NOM fractions with the molecular weight greater than 2000 Da were reduced by over 90% after C/F process. SUVA values and total carbohydrate content of the samples were well correlated with a ratio of protein-like fluorescence and terrestrial humic-like fluorescence intensities with the correlation coefficients of 0.99 and 0.91, respectively. This suggests that synchronous fluorescence properties of NOM could be used as useful tolls for monitoring changes of some NOM characteristics during water treatment processes.

• 응용통계연구
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• 제17권2호
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• pp.269-280
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• 2004

본 연구를 통하여 순위를 이용한 선형회귀모형의 가정된 분포형태가 우리가 실질적으로 많이 접하게 되는 비대칭분포이면서 만일 가정된 분포가 오른쪽으로 늘어진 경우일 때에는, 본 논문에서 제안된 스코어의 가능한 한 0 보다 크고 1 보다 작은 r 및 1 보다 큰 s 를 선택 (0 〈 r 〈 1, s 〉 1) 하는 것이 윌콕슨 스코어보다 높은 효율성을 나타낸다. 이와 반대로 만일 가정된 비대칭분포가 왼쪽으로 늘어진 경우일 때에는, 제안된 스코어의 가능한 한 1 보다 큰 r 및 0 보다 크고 1 보다 작은 s 를 선택 (r 〉 1, 0 〈 s 〈 1) 하는 것이 윌콕슨 스코어보다 높은 효율성을 나타낸다. 아울러 바람직한 r 과 s 를 결정하기 위한 가정된 분포의 대칭성 검정기법도 제시한다.

• 대한음성학회지:말소리
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• 제47호
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• pp.31-49
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• 2003

This paper investigates phonation types of Malay plosives and compares Malay plosives with Korean ones in terms of VOT, F0, duration of closure, and durations of the preceding and following vowels. This study is significant in that it specifies phonetic characteristics of phonation types of the two languages and provides phonetic bases for teaching and learning either of the two languages. The results showed that Malay voiceless plosives are greater than voiced ones in VOT, F0, duration of closure, but the other way in durations of the preceding and following vowels. Comparison of the two languages, particularly in terms of the distribution of VOT, indicates that Malay voiceless plosives are close to Korean fortis plosives.

• Journal of the Korean Statistical Society
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• 제24권1호
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• pp.141-147
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• 1995

A diffusion model for a system subject to random shocks is introduced. It is assumed that the state of system is modeled by a Brownian motion with negative drift and an absorbing barrier at the origin. It is also assumed that the shocks coming to the system according to a Poisson process decrease the state of the system by a random amount. It is further assumed that a repairman arrives according to another Poisson process and repairs or replaces the system i the system, when he arrives, is in state zero. A forward differential equation is obtained for the distribution function of X(t), the state of the systme at time t, some boundary conditions are discussed, and several interesting characteristics are derived, such as the first passage time to state zero, F(0,t), the probability of the system being in state zero at time t, and F(0), the limit of F(0,t) as t tends to infinity.

• 대한수학회논문집
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• 제16권2호
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• pp.287-290
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• 2001

Let X$_1$, X$_2$, … be a sequence of independent and identically distributed random variables with continuous cumulative distribution function F(x). X(sub)j is an upper record value of this sequence if X(sub)j > max {X$_1$, X$_2$, …, X(sub)j-1}. We define u(n) = min {j│j > u(n-1), X(sub)j > X(sub)u(n-1), n $\geq$ 2} with u(1) = 1. Then F(x) = 1 - e(sup)-x/c, x > 0 if and only if E[X(sub)n(n+1) - X(sub)u(n)│X(sub)u(m) = y] = c or E[X(sub)u(n+2) - X(sub)u(n)│X(sub)u(m) = y] = 2c, n $\geq$ m+1.

• 한국자기학회지
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• 제11권2호
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• pp.58-62
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• 2001

L $i_{0.5}$ F $e_{2.5-x}$A $l_{x}$ $O_4$ 페라이트계에 대한 XRD와 Mossbauer 스펙트럼을 측정 분석하였다. $Al^{3+}$ 씨온의 치환량 x가 증가할수록 격자상수는 작아지고, 값이 0, 0.3, 0.6인 시료에서는 두 site의 F $e^{3+}$ 이온에 의한 두 개의 6선 흡수선이 나타났고, x가 0.9, 1.2인 시료에서는 6선 흡수선외에 열에 의한 전자적 완화현상에 기인한 2선 흡수선이 공존하였으며, x가 1.5인 시료는 2선 흡수선만 나타났다. 공명흡수면적으로 계산된 L $i_{0.5}$ F $e_{2.5-x}$A $l_{x}$ $O_4$ 페라이트계의 금속 양이온 분포식은(L $i_{1-a}$$^{+}$F $e_{a}$ $^{3+}$ ) z으로 나타낼 수 있었고, 시료내의 $Al^{3+}$ 의 증가는 B-site의 F $e^{3+}$ - $O^{2-}$ 결합거리를 증가시켜 공유 결합성을 약화시키는 것으로 확인되었으며, $Al^{3+}$ 씨 증가에 따라 B-site의 F $e^{3+}$ 이온의 수가 감소하여 A-B 초 교환 상호 작용이 약화되는 것을 알 수 있었다.다.

• 대한토목학회논문집
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• 제4권3호
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• pp.75-83
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• 1984

사면(斜面)의 3차원(次元) 파괴(破壞)의 신뢰성(信賴性) 해석(解析)에 안전율(安全率) 대신 파괴확률(破壞確率)이 사용(使用)되었다. 강도정수(强度定數)는 정규분포(正規分布)와 베타분포(分布)로 가정하였고 특정(特定)한 신뢰도(信賴度)와 최우추정법(最尤推定法)에 의하여 구간추정(區間推定) 하였다. 정규분포(正規分布)와 베타분포(分布)의 무작위변수(無作爲變數)는 중심극한정리(中心極限定理)와 Rejection방법(方法)에 따라 일양분포변환방법(一樣分布變換方法)을 사용(使用)하여 발생(發生)시켰고 몬테칼로방법(Monte-Carlo Method)에 의한 파괴확률(破壞確率)은 다음과 같이 정의(定義)된다. $P_f=M/N$ N: 시행회수(施行回數) M: 파괴회수(破壞回數) 본(本) 연구(硏究) 결과(結果)는 다음과 같다. 1. $F_3$는 $F_2$보다 일반적으로 더 컸으나 작은 경우도 나타났다. 2. $F_3/F_2$의 비(比)는 c, ${\phi}$와 3차원(次元) 파괴(破壞)형상 그리고 경사에 따라 민감하나 흙의 단위중량에는 그렇지 않았다. 3. 어떤 완전율(安全率)에 대한 파괴확률(破壞確率)은 배타분포(分布)가 정규분포(定規分布)보다 대체로 크게 나타났다. 4. 어떤 특정(特定)한 사면파괴(斜面破壞)형상과 토질조건(土質條件)에 대하여 허용안전율(許容安全率) $FS_a=1.25$에 해한 $P_f$는 0.23 (정규분포(正規分布)), 0.29(베타분포(分布))로 나타났다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권14호
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• pp.5899-5902
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• 2015

Background: To compare the current histologic distribution of lung cancer in Lebanon to the worldwide trends, according to the 2004 WHO Classification. Materials and Methods: 1,760 patients with a pulmonary pathology examination at Hotel-Dieu de France University Hospital between July 2009 and July 2014 were included. Results: Some 676 out of the total investigated patients (38.4%) had a lung tumor. In 665 (98.4%) the tumors were malignant, with a mean age at diagnosis of 63.8 years and a male/female (M/F) sex ratio of 1.7:1. Among the malignant tumors, 86.2% were epithelial tumors with a mean age at diagnosis of 64.8 years and an M/F sex ratio of 1.9. Other malignant tumors consisted of metastatic tumors (10.2%), lymphoproliferative tumors (2.1%) and mesenchymal tumors (1.5%). Most common carcinoma subtypes were adenocarcinoma (48.0%), squamous cell carcinoma (23.0%) and small cell carcinoma (13.3%). Carcinoid tumors were the only carcinoma subtype with an M/F sex ratio below 1 (0.7). Salivary gland tumors were the carcinoma with lowest mean age at diagnosis (45.5 years). Conclusions: The histologic distribution of lung tumors in Lebanon is similar to that in developed countries. We believe this resemblance is due to common smoking habits, known to be responsible for the increase of lung adenocarcinoma at the expense of other subtypes.