• 한국환경과학회지
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• 제6권1호
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• pp.9-16
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• 1997

We investigated and analysed the actual conditions and characteristics of railroad noise levels for 17 sites in the vicinity of the Seoul-Pusan Line. The results i,we summarized as follows : 11 Railroad noise level ranged to 64 ~ 74 $L_{eq}$ dB(A) at day time and ranged to 60 ~ 72 $L_{eq}$ dB(A) at night time. 21 Increased night noise level depend on the increase of trains passing at night time. 31 The major factor of Increased noise level in the vicinity of stations are using loudspeakers and stream whistle on trains. 4) Decreased effect of noise according to distance is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$=$78.59^{X-0.056}$, n =25, r=-0.994, s.e. =1.007 $P_{av}$ = $105.68X^{-0.073}$, n =25, r =-0.997, s.e. = 1.007 Also increased and decreased effect of noise according to floor in apartment Is able to be described quantitatively using regression equations of multiplicative model. $L_{eq}$ = $64.238X^{0.0567}$, n = 39, r = 0.787, s.e. = 1.004 $P_{av}$ =79.963X0.0524, n =39, r =0.689, s.e. = 1.056 5) Average noise level in high floor is over 70 $L_{eq}$ dB(A) at day and night time. so more detailed soundproofing countermeasured in high floors apartment is required.

• 공업화학
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• 제30권4호
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• pp.421-428
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• 2019

본 연구에서는 천연색소인 커큐민을 포함하고 있는 천연물인 강황과 울금으로부터 황색색소(목표색, L = 87.0, a = 7.43, b = 88.2)를 추출하였다. 기초실험을 통해 반응표면분석법에 사용될 계량인자의 범위는 두 천연물 모두 pH (3~7), 추출온도($40{\sim}70^{\circ}C$)로 설정하였다. 목표색에 가장 근접한 최적추출조건을 얻기 위해 반응표면분석법 중 중심합성계획모델을 접목하여 추출공정을 최적화하였다. 결과값 및 회귀방정식을 통해 주효과도 및 교호효과도를 분석해 강황 및 울금의 색공간과 색차는 b 값에 가장 큰 영향을 끼치는 것을 알았다. 또한 반응치인 색좌표 L, a, b를 모두 만족하는 최적조건은 강황의 경우 pH = 3.43, 추출온도 $54.8^{\circ}C$에서의 이론적 수치 L (74.67), a (5.69), b (70.08)이었으며, 이 조건에서 실제실험을 수행한 결과 L (72.92), a (5.32), b (72.17)로 측정되었다. 울금의 경우에는 pH = 5.22, 추출온도 $50.4^{\circ}C$에서의 이론적 수치 색좌표는 L (82.02), a (7.43), b (72.86)이었으며, 실제실험을 수행한 결과 L (81.85), a (5.39), b (71.58)로 나타나 두 경우 모두 1% 이내의 오차범위를 나타내었다. 따라서 천연원료의 색소추출공정의 최적화 과정으로 반응표면분석법 중 중심합성계획모델을 적용할 경우 낮은 오차율을 얻을 수 있었다.

• 한국환경과학회지
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• 제27권11호
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• pp.1095-1104
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• 2018

The adsorption characteristics of bisphenol A (BPA) were investigated using activated carbon based on waste citrus peel (which is abandoned in large quantities in Jeju Island), denoted as WCP-AC, and surface-modified with various $P_2O_5$ concentrations (WCP-SM-AC). Moreover, coconut-based activated carbon (which is marketed in large amounts) was surface-modified in an identical manner for comparison. The adsorption equilibrium of BPA using the activated carbons before and after surface modification was obtained at nearly 48 h. The adsorption process of BPA by activated carbons and surface-modified activated carbons was well-described by the pseudo second-order kinetic model. The experimental data in the adsorption isotherm followed the Langmuir isotherm model. With increasing $P_2O_5$ concentration (250-2,000 mg/L), the amounts of BPA adsorbed by WCP-SM-AC increased till 1,000 mg/L of $P_2O_5$; however, above 1,000 mg/L of $P_2O_5$, the same amounts adsorbed at 1,000 mg/L of $P_2O_5$ were obtained. With increasing reaction temperature, the reaction rate increased, but the adsorbed amounts decreased, especially for the activated carbon before surface modification. The amounts of BPA adsorbed by WCP-AC and WCP-SM-AC were similar in the pH range of 5-9, but significantly decreased at pH 11, and increased with increasing ionic strength due to screening and salting-out effects.

• 대한환경공학회지
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• 제22권11호
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• pp.2017-2023
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• 2000

정유폐수의 성상에 적합한 동역학적 모델을 적용하여 활성슬러지법으로 처리할 때 모델의 적합성을 검토하기 위하여 실제 정유폐수 처리장 포기조내의 환경인자의 변화와 유출수 특성을 비교하였다 활성슬러지 포기조내 DO, pH, MLSS, COD의 실제 측정값과 비교하였다. Simulation한 결과, 유출수 평균 COD가 19.0~19.4mg/L로 측정 COD 23.1mg/L와 잘 일치하였고, 포기조내 평균 DO는 1.9~2.4mg/L로 예측되었는데 측정된 평균 DO가 2.2mg/L로 잘 일치하여 모델의 정유폐수 처리장의 적용 가능성이 검토되었다.

• KSBB Journal
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• 제13권6호
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• pp.730-734
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• 1998

An이ew식과 Aiba삭을 조합하여 에탄올 생산단주인 Saccharomyces cerevisiae ATCC 24858의 비성장속도를 당농도와 에탄올 농도의 함수로 표현하였다. 기침의 저해영향을 받지 않는 최대 당농도 $S_m$은 150 g/L이며 기질의 저해영향은 기질농도 S와 $S-S_{max}$항의 함수로 표현되었다. 최대 비성장 속도 ${\mu}max 는 0.49 hr^{-1}, Monod상수 K_s$는 19 g/L, Andrew식의 기질저해상수 $K_1$는 139 g/L이였다. 또한 비성장속도에 영향을 마치지 앓는 최대알콜농도 Pm이 존재하였으며 그 값은 2 g/L 이였다. 따라서 Aiba식에서 비성장속도에 영향을 미치는 에탄올 농도항은 P-Pm으보 표현되었다. 본 연구의 알코올생산균주에 대한 비성장속도의 완성된 수식은 디음과 같으며 이 수식에 위한 계산값은 평균오차 6% 내외의 범위에서 실험값과 일치하였다.

• 대한수학회보
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• 제41권2호
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• pp.337-345
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• 2004

In allelic model X = ($\chi_1\chi$_2ㆍㆍㆍ, \chi_d$), M_f(t) = f(p(t)) - ${{\int^t}_0}\;Lf(p(t))ds$ is a P-martingale for diffusion operator L under the certain conditions. In this note, we can show existence and uniqueness of solution for stochastic differential equation and martingale problem associated with mean vector. Also, we examine that if the operator related to this martingale problem is connected with Markov processes under certain circumstance, then this operator must satisfy the maximum principle.

• 전력전자학회논문지
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• 제17권5호
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• pp.388-392
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• 2012

In this paper, a sampler model for the P-type current mode control employing low pass filter is proposed. Even though the frequency response of the compensator used in a P-type current mode control employing low pass filter is similar to that of P-type compensator, the sampler model has to be obtained from the method used in PI-type current mode control. In order to show the usefulness of the proposed method, prediction results of the proposed model are compared to those from the circuit level simulator, PSIM.

• 대한간호학회지
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• 제47권4호
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• pp.514-525
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• 2017

Purpose: The purpose of this study was to construct and test a structural equation model for Diabetes self-management (DSM) behavior and Quality of life (QoL) in older adults with diabetes who use Citizen Health Promotion Centers. The theory used this study was a combination of the Information-Motivation-Behavioral Model (IMB) and Self-Determination Theory (SDT) to reflect autonomous characteristics of participants. Methods: Data were collected from April 20 to August 31, 2015 using a self-report questionnaire. The sample was 205 patients with type 2 Diabetes who regularly visited a Citizen Health Promotion Center. SPSS 22.0 and AMOS 22.0 programs were used to analyze the efficiency of the hypothesized model and calculate the direct and indirect effects of factor affecting the participants' DSM behavior and QoL. Results: The supported hypotheses were as follows; 1) The variable that had a direct effect on QoL was health behavior adherence (${\gamma}=.55$, p=.007). 2) The variables that had a direct effect on DSM behavior were DSM information (${\gamma}=.15$, p=.023), DSM confidence (${\gamma}=.25$, p<.001), and autonomous motivation (${\gamma}=.13$, p=.048). 3) The variable that had a direct effect on DSM confidence was autonomy support (${\gamma}=.33$, p<.001). Conclusion: The major findings of this study are that supporting patient's autonomous motivation is an influential predictor for adherence to DSM behavior, and integrative intervention strategies which include knowledge, experience and psychosocial support are essential for older adults with diabetes to continue DSM behavior and improve QoL.

• Bulletin of the Korean Chemical Society
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• 제18권11호
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• pp.1162-1166
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• 1997

Nature of palladium(Ⅱ) complexes with 7-membered chelates was studied by experimental and theoretical methods on a Pd(L)Cl2 system, where L is Ph2PNHCH2CH2NHPPh2(L1), Ph2PNHC6H4NHPPh2(L2). The palladium(Ⅱ) complexes were prepared and characterized by elemental analysis, IR, UV, 1H, and 31P NMR spectroscopy. Ab initio calculations with geometry optimizations were also performed for related model systems, Pd(L)Cl2; L=R2PNH(CH2)2NHPR2(L3), R2PNHC6H4NHPR2(L4), R2P(CH2)4PR2(L5), R2PCH2(C6H4)CH2PR2(L6); R=H, CH3.

• 공업화학
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• 제24권3호
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• pp.299-304
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• 2013

Box-Behnken design (BBD) 방법은 일체형 흡착제의 합성조건을 최적화하기 위해 사용되었다. 단량체(monomer)의 양(mL), 가교제(crosslink)의 양(mL), porogen의 양(mL)에 대한 효과를 조사했다. 실험 값은 여러 회귀분석 및 통계적인 방법에 의해 2차 다항 방정식을 얻었다. 이 모델의 결정계수($R^2$)는 0.9915이고 결정계수의 p value는 0.0001보다 작은 값으로 모델이 매우 유의미하다는 것을 나타낸다. RSM 모델에 의해 예측된 최적의 일체형 흡착제 합성조건은 단량체의 양 0.30 mL, 가교제의 양 1.40 mL, porogen의 양 1.47 mL이고 이 조건 아래서 합성된 일체형 흡착제의 양은 2120.15 mg이다. 이 결과는 이 모델이 적절하다는 것을 나타내었다.