• 한국환경농학회지
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• 제36권2호
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• pp.113-118
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• 2017

DOC의 ${\delta}^{13}C$은 수질 오염원 규명에 활용할 수 있는 매우 유용한 지표이다. 본 연구에서는 안정성동위원소비 질량분석기(EA-SIRMS)를 이용하여 DOC의 ${\delta}^{13}C$을 분석할 때 사용하는 두 가지 전처리방법 (과황산칼륨산화-$SrCO_3$침전법과 동결건조법)의 정확도를 비교 평가하였다. 표준물질로는 글루코스(${\delta}^{13}C$; $-12.0{\pm}0.02$‰)와 돈분퇴비 침출액 건조분말(${\delta}^{13}C$; $-23.3{\pm}0.04$‰)을 사용하였다. 과황산칼륨산화-$SrCO_3$ 침전법에서는 용액의 알칼리성에 의해 DIC 제거가 어렵고 공기 중 $CO_2$의 영향에 의해 시료가 오염되어 분석결과의 정확도가 매우 낮았다. 반면, 동결건조법은 산 첨가에 의해 제거가 가능하였고, 측정값과 이론값의 상관관계가 매우 높아 실험조건별로 표준물질을 이용하여 측정값을 이론값에 근접하게 보정할 수 있는 것으로 나타났다. 따라서, EA-SIRMS를 이용하여 DOC의 ${\delta}^{13}C$ 분석시 동결건조법으로 시료를 전처리하면 분석결과의 정확도를 증대시킬 수 있을 것으로 판단된다.

• 한국물환경학회지
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• 제26권6호
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• pp.969-975
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• 2010

Estimating the organic matter loadings from individual treated sewage has become important for establishment of effective management strategies to control refractory organic matter (R-OM) in watersheds. For this study, regression equations were constructed using treated sewage data to convert the chemical oxygen demand (COD) concentrations, which are mostly available from open database, into total organic carbon (TOC) and R-OM concentrations. Effluent samples were collected from five major sewage treatment plants (STPs) located upstream of the lake Paldang. Variations in the OM concentrations were not associated with either the location of the STP or the sampling season. The effluent investigated were characterized by higher ratio of R-OM with respect to biodegradable organic matter (B-OM) and higher presence of dissolved organic matters (DOM) versus particulate organic matter (POM). Compared to $COD_{Mn}$, $COD_{Cr}$ exhibited higher oxidation efficiencies and greater variations in the concentrations. The concentrations of $COD_{Mn}$ were positively correlated with dissolved organic carbon (DOC), total organic carbon (TOC), and R-OM concentrations. There was nearly no seasonal and annual variation in the regression equations between $COD_{Mn}$ and TOC or R-OM concentrations. The constructed regression equations for TOC and R-OM were $0.650({\pm}0.071){\times}COD_{Mn}+1.426({\pm}0.575)$ and $0.340({\pm}0.083){\times}COD_{Mn}+2.054({\pm}0.670)$, respectively. The established equations are expected to contribute to estimating OM loadings from the STPs into the lake Paldang and also to compensating for the deficiency of the data for effluent OM concentrations in STP.

• 한국환경보건학회지
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• 제33권2호
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• pp.158-165
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• 2007

본 연구는 근원에 따른 용존 유기물의 특성을 평가하기 위해 하천수, 호소수, 하수 2차 처리 유출수의 자연수 및 Aldrich, Wako 사에서 공급된 휴믹산을 대상으로 분자량 분포에 따른 물리 화학적인 수질 특성, 생분해도, 소독, 부산물의 생성 등을 고찰하였다. SUVA를 이용해서 자연수의 생분해 가능성을 평가한 결과 호소수, 하수, 하천수 순으로 예측되었으며 이는, 실제 생분해도 실험 결과와 유사하였다 생분해 반응 중 저분자 영역대의 용존 유기물은 점차 감소하였고 반면에 고분자 영역대의 용존 유기물은 증가하였다. SMP는 전체 용존 유기물의 0.7-5.5%정도 관찰되었으며 고분자 물질을 많이 함유한 시료에서 높게 나타났다. THM 생성은 대체로 고분자 물질이 높을수록 증가하였으며 THMFP도 Wako 휴믹산을 제외한 샘플에서 이와 유사한 경향을 나타냈다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 가을 학술발표회 논문집
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• pp.214-224
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• 1999

The design response spectrum has been widely used in seismic design to estimate force and deformation demands of structures imposed by Earthquake Ground Motion (EQGM). Inelastic Design Response Spectra (IDRS) to specify design yielding strength in seismic codes are obtained by reducing the ordinates of Linear Elastic Design Response Spectrum (LEDRS) by strength reduction factor (R). Since a building is designed using reduced design spectrum (IDRS) rather than LEDRS in current seismic design procedures it allows structures behave inelastically during design level EQGM. Inelastic Response Spectra (IRS) depend not only on the characteristics of the expected ground motion at a given site, but also on the dynamic properties and nonlinear characteristics of a structure. However, it has not been explicitly investigated the effect of different hysteretic models on IRS. In this study, the effect of hysteretic models on IRS is investigated.

• 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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• 한국정보과학회언어공학연구회 2022년도 제34회 한글 및 한국어 정보처리 학술대회
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• pp.141-145
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• 2022

다중 문서 기반 대화 시스템에서 응답 시스템은 올바른 답변을 생성하기 위해서 여러 개의 문서 중 질문과 가장 관련 있는 문서를 검색하는 것부터 시작해야 한다. DialDoc 2022 Shared Task[1]를 비롯한 최근의 연구들은 대화 시스템의 문서 검색 과정을 위해 Dense Passage Retrieval(DPR)[2] 모델을 사용하고 있으며 검색기의 성능 개선을 위해 Re-ranking과 Hard negative sampling 같은 방법들이 연구되고 있다. 본 논문에서는 문서에 기반하는 대화 데이터의 양이 적거나 제한될 경우, 주어진 데이터를 효율적으로 활용해 보고자 검색기를 생성 모델을 이용하여 문서의 엔티티를 기반으로 질문을 생성하고 기존 데이터에 증강하는 방법을 제시했으며 실험의 결과로 MRR metric의 경우 0.96 ~ 1.56의 성능 향상을, R@1 metric의 경우 1.2 ~ 1.57의 성능 향상을 확인하였다.

• 대한산업공학회지
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• 제41권6호
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• pp.530-539
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• 2015

A business model (BM) can be developed based on a business model framework (BMF) consisting of key components such as value proposition, customers, and resources. To systematically generate and analyze emerging BMs such as healthcare BM, an integration of diverse BMF components is needed. The present study is to establish a comprehensive BMF and evaluate its applicability to healthcare BMs. Based on a review of eight BMF studies, ten BMF components were identified and classified into five major components (value proposition, resources, organizing model, customers, and revenue model) and five minor components (technology, service platform, delivery, competitive strategy, and growth/exit) by analyses of frequency and functional importance. Lastly, the BMs of three emerging healthcare companies (WellDoc, Inc., CFW Shops, and Aravind Eye Care System) were analyzed and compared in terms of the proposed BMF components. The comprehensive BMF components presented in the study can be of help for developing new BMs and analyzing the strengths and weaknesses of BMs.

• 한국환경보건학회지
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• 제30권5호
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• pp.410-416
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• 2004

The objective of this investigation was to evaluate applicability of precoat filtration that can be substituted for rapid sand filter of conventional water treatment system(CWTS). Precoat filter used in this experiment are candle filter. Element disk of candle are pore size $10{\mu}m(R),\;20{\mu}m(B)$ And diatomaceous earth are cake pore size $3.5{\mu}m$(Standard Super- Cel; A), $7{\mu}m$(Hyflo Super-Cel; B) and $17{\mu}m$(Celite 545RV; C). $2kg/m^2$ diatomaceous earth is used for precoating, it coated candle in $5{\sim}6mm$ thickness. 1. Al adsorption dosages by diatomaceous earth used in experimental we Hyflo Super-Cel 0.843mg/g, Standard Super-Cel 0.782 mg/g and Celite 545RV 0.766 mg/g. 2. Filtrate of precoat filter during 60min are R-C combination 20.7($m^3/m^2$)>B-C 18.3($m^3/m^2$)>B-B 15.0($m^3/m^2$)> R-B 12.9($m^3/m^2$)> R-A 11,093($l/m^2$). 3. Water quality of precoat filter effluent are thus. $KMnO_4$ consumption are $1.10{\sim}2.20mg/l$, removal rate are $30.9{\sim}65.6\%$. They are R-A 1.10(mg/l)(removal rate $65.6\%$). R-C(2.20 mg/l)(removal rate $30.9\%$). 4. $Al^{3+}$ are not detected with all combination, removal rate $100\%$. 5. Considering water quality and flux, continued running time of R-A combination is 7 hr. Accumulated filtrate are $74.4 m^3/m^2$, average flux is $177.2 l/m^2{\cdot}min$. And filtrate per diatomaceous earth 1g are 37.2 l. 6. R-A effluent's water quality are $KMnO_4$ Consumption 1.10(mg/l), DOC 1.161 mg/1, Al 0.0 mg/1, $UV_{254}$ 0.016/cm, Turbidity 0.1(NTU). R-A combination is suitable to precoat filtration for the settling basin effluent treatment.

• 대한환경공학회지
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• 제36권8호
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• pp.542-548
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• 2014

본 연구에서는 염소처리시 요오드계 트리할로메탄(iodo-trihalomethanes, I-THMs)의 생성에 영향을 미치는 인자들을 조사하였다. 염소를 소독제로 사용하여 염소 투입농도, 수온, pH, 브롬이온과 요오드이온 농도, 염소 접촉시간, 암모니아성 질소농도 및 용존 유기물질의 특성 변화에 따른 I-THMs 6종에 대한 생성특성을 조사하였다. 수중의 요오드이온과 브롬이온의 농도가 증가할수록 I-THMs의 생성농도가 증가하였으며, 염소 투입농도 및 수온에 따른 I-THMs 생성에서는 염소 투입농도 및 수온 상승에 비례하여 I-THMs 생성농도도 증가하다가 염소 투입농도 3 mg/L 및 수온 $30^{\circ}C$ 이상의 조건에서는 오히려 I-THMs 생성농도가 감소하였다. 또한, 시료수의 pH가 상승할수록 I-THMs의 생성농도가 증가하였다. 수중의 $NH{_4}{^+}-N$ 농도가 증가할수록 염소와 반응하여 생성된 클로라민에 의해 I-THMs 생성농도가 증가하였다. 하수처리장 방류수, 휴믹산 조제수, 조류유래 유기물질 함유수 및 4개의 낙동강 시료수(고령, 매리, 하구 및 진천천)와 같은 7개의 시료수의 유기물질과 I-THMs와의 반응성을 조사한 결과, 하수처리장 최종방류수가 I-THMs와의 반응성($12.31{\mu}g/mg$)이 가장 높았고, 다음으로 휴믹산 시료수($4.96{\mu}g/mg$)로 나타났고, 조류유래 유기물질이 가장 낮은 결과($0.99{\mu}g/mg$)를 나타내었다. 또한, $SUVA_{254}$값과 I-THMs 반응성과의 상관성을 평가한 결과에서 상관계수($r^2$)가 0.002로 매우 낮게 나타나 $SUVA_{254}$값과 I-THMs 생성과는 연관성을 찾기가 어려웠다.

• 한국물환경학회지
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• 제22권6호
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• pp.1137-1143
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• 2006

In this study we investigated the removal characteristics of NOM and bromate formation characteristics in SOMT reactor. The system was recently developed as a novel ozone reactor and installed in SJ pilot plant. DOC values were decreased within 3% after treatment of 0.5~2.0 mg/L ozone dosage in SOMT reactor while the $UV_{254}$ value was 69% decreased at 2.0 mg/L ozone dosage. The composition of NOM was analysed by LC-OCD (Organic Cabon Detector) after ozone treatment in SOMT reactor to elucidate the variation of NOM character. Polysaccharide (more than 20,000 g/mol) fraction of NOM was decomposed while building blocks (350~500 g/mol) and neutral (less than 350 g/mol) fraction increased. Spiked bromide reacted with 0.5~2.0 mg/L ozone dosage in the SOMT reactor. The bromate formation was proportional to the ozone dosage ($R^2=0.978$) but not proportional to reaction time. The maximum concentration of formated bromate was not exceeded to 10% of spiked bromide concentration.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1678-1682
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• 2001

The total proteins were estimated in both deoxycholate (DOC)-extract of sperm membrane and seminal plasma of chilled as well as frozen semen obtained from five Murrah buffalo bulls. Proteins were further characterized by polyacrylamide gel electrophoresis (PAGE) in three bulls. The protein content of sperm membrane extract (SME) and that of seminal plasma (SP) decreased gradually with increase in freezing period from 6 to 24 mo when compared with the values observed in freshly chilled semen in all bulls. The total decrease in protein content of SME and SP varied from 30-40% and 28-59% respectively during 6-24 mo of freezing. The number of glycoproteins/proteins (GP/P) in SME varied from 4-8 in freshly-chilled semen of all bulls and reduced to 2-4 after 24 mo of freezing. In SP, the number of proteins varied from 6-10 in freshly chilled semen of all bulls and reduced to 3-8 after 24 mo of freezing. Some of the proteins in SME and SP disappeared, others got altered and appeared with change in molecular weight after different freezing times. These studies reveal that alterations in the sperm membrane proteins may be responsible for damage to their membrane during freezing and thus lowering their fertilizability.