• 한국자기학회:학술대회 개요집
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• 한국자기학회 2007년도 The 1st International Symposium on Advanced Magnetic Materials
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• pp.77.1-77.1
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• 2007

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.71-73
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• 1994

In this paper we have investigated discharge conditions(parameters of this experiment) in facing targets sputtering system and fabricated $Al_{N}$ thin films. The parameters of this study are diameter of wing(d) and distance(L) between two facing targets. Varing discharge conditions, the discharge characteristics are wide different. The optimal conditions in this experiments are d = 6.5 [cm], L = 6.5[cm]

• 한국환경농학회지
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• 제18권2호
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• pp.122-125
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• 1999

The water quality of the Keum river was surveyed at 4 sites from April to September in 1995 and 1997. Average values of inorganic contents analyzed in 1997 were pH 7.2, EC 0.18dS/m, $NH_4-N$ 0.60mg/l, $K^+$ 4.12mg/l, $Ca^{2+}$ 12.12 mg/l, $Mg^{2+}$ 2.75mg/l, $Na^+$ 15.1mg/l, $NO_3-N$ 1.97mg/l, $PO_4^{3-}$ 0.15mg/l, $PO_4^-$ 18.9mg/l, $Cl^-$ 21.8mg/l, Fe 0.22mg/l, COD 19.7mg/l. On the basis of these values, it was suitable for the irrigation source. Water pH of the Keum river ranged from 6.7 to 8.0. EC of the Daecheong-dam was maintained below 0.13dS/m, but those of the middle and lower stream were ranged from 0.13dS/m to 0.32dS/m. Monthly average values of all the ration contents were the highest in April and were decreased thereafter. And it was slightly increased in September. However $NO_3-N$, $SO_4^{2-}$ contents were higher in June than any other months. All the inorganic contents were the highest at Taepyeong-ri, Yeongi-gun due to sewage water and livestock wastes. The inorganic contents were negatively correlated with precipitation, generally.

• Clinical and Experimental Pediatrics
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• 제62권5호
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• pp.166-172
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• 2019

Purpose: This study aimed to evaluate vitamin D status at birth in very-low-birth-weight infants (VLBWIs: <1,500 g) and to determine the association between vitamin D level and respiratory morbidity. Methods: A retrospective study was conducted at Soonchunhyang University Bucheon Hospital between November 2013 and November 2017. We collected blood samples and data on respiratory morbidity from 230 VLBWIs on the first day of life. Patients who were transferred to other hospitals (n=19), died before 36 weeks of gestational age (n=18), or whose blood samples were not collected immediately after birth (n=5) were excluded. Finally, 188 patients were enrolled. VLBWIs with different vitamin D levels were compared with respect to demographic features, maternal diseases, respiratory morbidities, and other neonatal diseases. Results: The mean serum vitamin D level, as measured by 25-hydroxyvitamin D (25(OH)D), was $13.4{\pm}9.3ng/mL$. The incidence of vitamin D deficiency (<20 ng/mL) was 79.8%, and 44.1% of preterm infants had severe vitamin D deficiency (<10 ng/mL). Logistic analysis shows that a low serum 25(OH)D level (<20 ng/mL) was a risk factor for respiratory distress syndrome (odds ratio [OR], 4.32; P=0.010) and bronchopulmonary dysplasia (OR, 4.11; P=0.035). Conclusion: The results showed that 79.8% of preterm infants in this study had vitamin D deficiency at birth. Low vitamin D status was associated with respiratory morbidity, but the exact mechanism was unknown. Additional studies on the association between vitamin D level and neonatal morbidity are required.

• Bulletin of the Korean Chemical Society
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• 제13권3호
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• pp.285-289
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• 1992

Enantiomeric separation of underivatized amino acids using N-alkyl-L-proline (octyl, dodecyl or hexadecyl) coated HPLC has been accomplished. The anchoring N-alkyl groups of L-proline provides a permanent adsorption of there solving chiral agent on the hydrophobic interface layer of a reversed phase. The factors controlling retention and enantioselectivity such as the Cu(II) concentration, pH of the eluent, the type and concentration of organic modifier in the hydroorganic eluent, and extent of coating were examined. The elution orders between D- and L-amino acids were consistent, L-forms eluting first, except histidine and asparagine. The extremely high enantioselectivity $(\alpha$ upto 13 for proline) is observed. The retention mechanism for the chiral separation can be illustrated by a complexation and hydrophobic interaction.

• 한국환경농학회지
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• 제26권2호
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• pp.99-106
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• 2007

낙동강수계내 농촌유역의 토지이용 및 수질특성과의 관련성을 파악하기 위해서, 주요 농촌 소유역 중소하천 72지점을 대상으로 2001년, 2003년, 2005년의 수질을 각 년 3회씩 각 유역별로 조사하였다. 또한 유역의 오염현황과 유역특성과의 관계도 분석하고자 하였다. 낙동강 상류의 수질은 EC의 경우, $0.040\sim0.510$ dS/m, DO는 $3.55\sim22.60$ mg/L, T-N이 $0.32\sim16.64$ mg/L, $NO_3-N$은 $0.00\sim12.21$ mg/L, T-P는 $0.000\sim0.860$ mg/L, $PO_4-P$는 $0.000\sim0.640$ mg/L로 조사되었고 하류의 수질은 EC의 경우, $0.030\sim0.520$ dS/m, DO는 $4.13\sim18.36$ mg/L, T-N이 $0.38\sim26.88$ mg/L, $NO_3-N$은 $0.10\sim20.12$ mg/L, T-P는 $0.002\sim0.820$ mg/L, $PO_4-P$는 $0.00\sim0.690$ mg/L로 조사되어 소유역별 수질은 큰 차이는 없었지만 전반적인 경향은 낙동강 상류지역의 소유역에서 유출되는 오염도가 하류지역의 소유역보다 높게 조사되었다. 수질과 토지이용의 점유율과의 상관관계는 BOD와 시가화가 0.541(p<0.01)로 가장 높은 양의 상관관계를 보였고, $PO_4-P$가 산림과 -0.451(p<0.01)로 가장 낮은 음의 상관관계를 보였다. T-N, $NO_3-N$, pH는 모든 유역 특성과 유의성이 없었고 수역은 모든 수질 항목과 유의성이 없었다. 또한 시가화는 T-N, $NO_3-N$, pH을 제외한 모든 수질 항목에서 유의수준 1%이내로 양의 상관관계를 나타내어 수질 악화의 원인으로 작용하였고 산림의 경우 대부분의 수질과 음의 상관관계를 보여 수질 개선의 요인으로 작용하였다.

• 대한수학회보
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• 제33권1호
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• pp.135-170
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• 1996

Recently many people have studied the Sobolev orthogonal polynomials, that is, polynomials which are orthogonal relative to a symmetric bilinear form $\phi(\cdot,\cdot)$ defined by $$ (1.1) $\phi(p,q) := (p,q)_N = \sum_{k=0}^{N} \int_{R}p^(k) (x)q^(k) (x) d\mu_k, $$ where each $d\mu_k$ is a signed Borel measure on the real line $R$ with finite moments of all orders. For the brief history on this subject, we refer to the survey article Ronveaux [13] and Marcellan and et al [10].

• 약학회지
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• 제41권3호
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• pp.277-282
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• 1997

Methamphetamine, which is the most commonly abused drug in Korea, exists in terms of d-, l- isomers and a racemate(dl). d-Methamphetamine is a potent central nervous system stimulant, whereas l-Methamphetamine is sold freely as a nasal decongestant. In addition, methamphetamine appears in different ratios of optical isomers by the clandestine synthesis applied. In this study, enetiomeric separation of methamphetamines was estabilished to distinguish the chirality of methamphetamines trafficked and abused in Korea. A gas chromatograph/mass spectrometer(GC/MS) system equipped with an achiral capillary column is used to isolate the isomers of methamphetamine after (S)-N-(trifluoroacetyl)-l-prolyl(TFP) deravatization.After analyzing 10 illicit methamphetamine powders and 10 positive urine samples, following findings were found: d-Methamphetamine was well resolved from l-Methamphetamine by chromatographic separation of TFP derivatibes on DB-5 with retention time of 11.80 and 11.35 min respectively. The detection of d-Methamphetamine in all 10 powders and 10 urine samples proves that all methamphetamines abused in Korea are illegally manyfactured and administred.

• 한국정보통신학회논문지
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• 제14권3호
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• pp.637-647
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• 2010

본 논문에서는 'w bit $\times$ w bit = 2w bit' 곱셈기를 사용하여 2w 비트 정수 N과 w 비트 정수 D의 $\frac{N}{D}$용 나눗셈을 수행하는 알고리즘을 제안한다. 본 연구에서 제안하는 알고리즘은 제수 D가 '$D=0.d{\times}2^L$, 0.5 < 0.d < 1.0'일 때, '$0.d{\times}1.g=1+e$, e < $2^{-w}$'가 되는 '$\frac{1}{D}$'의 근사 값 '$1.g{\times}2^{-L}$'을 가칭 상역수로 정의하고, 피제수 N을 'w-3' 비트 보다 작은 워드로 분할하고, 각 분할된 워드에 상역수를 곱해서 부분 몫을 계산하고, 부분 몫을 합산하여 배정도 정수 나눗셈의 몫을 구한다. 제안한 알고리즘은 정확한 몫을 산출하기 때문에 추가적인 보정이 요구되지 않는다. 본 논문에서 제안하는 알고리즘은 곱셈기만을 사용하므로 마이크로프로세서를 구현할 때 나눗셈을 위한 추가적인 하드웨어가 요구되지 않는다. 그리고 기존 알고리즘인 SRT 방식에 비해 동작속도가 빠르다. 따라서 본 논문의 연구 결과는 마이크로프로세서 및 하드웨어 크기에 제한적인 SOC(System on Chip) 구현 등에 폭넓게 사용될 수 있다.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 1993년도 EARTH 발표논문초록
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• pp.11.2-12
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• 1993