• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2012년도 학술발표회
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• pp.587-587
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• 2012

현재 대부분 하천관리의 흐름해석에서 주가 되었던 1차원 분석은 하천 단면에 따른 횡적인 수면차, 유속분포를 분석할 수 없다는 단점을 가지고 있으며, 특히 유량 및 유속이 급속도로 늘어나는 홍수시에는 그 오차가 더욱 커질 수 있다. 반면에 2차원 모형의 흐름해석은 사행하천의 흐름 특성과 만곡부에서의 종 횡방향 수면경사 및 양안의 수면차와 합류지점의 횡방향 흐름 등의 영향을 고려할 수 있으며 1차원 해석과는 달리 전 단면에 걸쳐 유속 및 수위 분포를 나타낼 수 있어 실제흐름에 가까운 수리량을 얻을 수 있다. 본 연구를 위해 적용된 해석모형인 SMS는 미국 Brigham Young 대학의 환경모형연구실과 미공병단(USACE)의 수로실험국(WES) 등에서 개발한 프로그램으로서 RMA2, RMA4, SED2D 모형 등으로 구성되어 있다. 각각의 모형은 수리 동역학적 해석, 오염물 이송확산 해석, 유사의 이송 및 퇴적 해석이 가능하며 이 중 RMA2를 이용한 2차원 흐름해석을 통하여 보다 적합한 하천관리에 이용가능하도록 하고자 한다. 연구대상 지역은 제주도 한천 하류부로서 제주도 하천 특성상 평상시 건천의 상태를 이루고 있으나 태풍 및 집중호우시 홍수유출이 발생하여 수위가 급격하게 상승하는 양상을 보인다. 대표적인 예로 태풍 '나리'시 최대 일강우량 420mm로 인한 인근 지역에 0.5 ~ 1.5m의 침수흔적을 보이고 있다. 본 연구에서는 2011년 최고수위를 기록한 태풍 '무이파'를 대상으로 하였으며 대상지역의 Kalesto를 이용한 수위-유속 자료를 이용하여 산출된 유량을 경계조건으로 사용하였고 격자망 형성을 위한 지형 데이터는 지형도 및 측량자료를 이용하여 구축하였다. 사용된 대표적인 매개변수는 하상의 조도계수를 나타내는 Manning의 n값과 유체의 밀도, 속도구배, 구조 등 여러 가지의 유체조건에 따라 변하는 성질인 와점성계수(eddy viscosity)로 요약할 수 있으며 Manning의 n값은 하천설계기준에 따른 하천기본계획의 조도계수를 사용하였고 와점성계수는 적합한 흐름 분포를 결정하기 위해 흐름이 안정될 때까지 변화시켜 해석을 시행하였다. 해석결과 만곡부에서는 급한 흐름을 보이고 있으며 최대하폭 구간에서는 완만한 흐름이 나타나 사행하천의 흐름특성과 횡적인 하천단면에 따른 변화, 하상고 차이로 인한 유속분포를 확인할 수 있으며 이는 보다 유용한 하천관리에 이용가능할 것으로 사료된다.

• Journal of Nutrition and Health
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• 제25권2호
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• pp.162-178
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• 1992

This study evaluated the effectiveness of affected-based program in changing the nutrition attitudes and behavior of a group of low-income housewives in a urban area near industrial complex. using pre- post- and one month retention test measures of nutrition attitudes knowledge and nutrition behavior. The sample consisted of treatment group(n=58) and control group(n=68, 66 or 61) The treatment group participated in a four-week nutrition course of eight hours offered by faculty members of department of Food and Nutition in Han Nam University. At the conclusion of the program the respondents had improved nutrition attitudes increa-sed nutrition knowledge and improved dietary diversity and dietary quality scores. Nutrition attitude scores rose significnatly from the pretest to post-test for the treatment group only However this improvement was not maintained one month after education. Nutrition know-ledge score of the treatment group increased significnatly from the pretest to posttest and pretest to retention test. Nutrition behavior was measured by food practice dietary diversity and dietary quality scores, The mean food practice score dietary diversity and dietary quality scores were signifi-cantly increased from pretest to posttest for the treatment group. Only dietary diversity scores was maintained from posttest for the retention test for the treatment group. There was a good correlation between nutrition knowlege and attitude scores at the pretest. However no significant corrlation was found between nutrition knowledge and attitude scores at the posttest. At the pretest nutrition knowledge or attitude and behavior were not correlated bu there were significant correations between nutrition knowledge or attitude and behavior at the posttest. It was concluded that a four-week nutrition education program of eight hours duration for the target people can lead to ac hange in dietary behaviors as well as nutrition knowledge and attitude.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.259-259
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• 2018

최근 우리나라는 기후변화에 따른 태풍발생빈도 증가 및 이상강우, 유역내 토지이용의 고도화로 인한 유역특성 변화로 유역내 홍수량은 증가하고 홍수 도달시간이 짧아지는 양상을 보이고 있다. 이로 인해 홍수에 따른 치수방어 대책으로 하천의 제방축조 및 보강방법이 주로 채택되었으나, 최근에는 홍수시 직접적인 하천내 수위 저감을 위한 방안으로 하도내 저류효과를 확대하기 위한 보 설치 및 하도정비를 통한 하도준설을 시행하고 있다. 그러나 본류 하상저하에 따른 지류하천의 하상변동(두부침식)으로 하도내 세굴 침식에 의한 하천시설물 피해 사례가 늘게 되면서 과거 홍수에 의한 제방월류 피해에서 하상변동에 의한 하천시설물 붕괴로 하천피해 양상이 바뀌게 되었다. 이와 같은 피해를 방지하기 위해 지류하천 합류부에 하상변동 방지책으로 하상유지공을 설치하고 있지만 국내에는 이와 관련된 구체적 설계기준 및 연구가 미비하여 일선에서는 아직도 하천구조물의 용도가 다른 보나 낙차공의 설계기준을 준용하는 등 하상유지공 용도에 특성화된 설계기준(최적 위치선정 및 형식 등)이 없는 실정이다. 본 연구에서는 감천(낙동강 지류하천)유역내 하도준설 및 홍수로 인한 하상유지공의 유실에 따른 지류하천의 피해사례를 통해 수치해석결과 및 실측자료를 바탕으로 하상유지공 계획의 중요성을 검증하고자 하였다. 또한 하도준설로 생성된 지류합류부의 단차구간에 안정성을 확보한 최적의 하상유지공 위치 및 형식 등을 선정 검토하고 설치 유 무에 따른 유수흐름 및 하상변화양상을 비교 분석하였다. 본 연구의 결과를 토대로 향후 하도굴착 및 하상유지공 계획시 고려해야할 사항(지형현황 및 수리특성 등)을 인지하고 극한상황에서도 안전한 하상유지공의 위치 및 형식 등을 선정하는데 활용 가능할 것으로 판단된다.

• Toxicological Research
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• 제35권2호
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• pp.137-154
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• 2019

Triclosan (TCS) is an antimicrobial compound used in consumer products. The purpose of current study was to examine toxicology and risk assessment of TCS based on available data. Acute toxicities of oral, transdermal and inhalation routes were low, and phototoxicity and neurotoxicity were not observed. Topical treatment of TCS to animal caused mild irritation. TCS did not induce reproductive and developmental toxicity in rodents. In addition, genotoxicity was not considered based on in vitro and in vivo tests of TCS. It is not classified as a carcinogen in international authorities such as International Agency for Research on Cancer (IARC). No-observed-adverse-effect level (NOAEL) was determined 12 mg/kg bw/day for TCS, based on haematoxicity and reduction of absolute and relative spleen weights in a 104-week oral toxicity study in rats. Percutaneous absorption rate was set as 14%, which was human skin absorption study reported by National Industrial Chemicals Notification and Assessment Scheme (NICNAS) (2009). The systemic exposure dosage (SED) of TCS has been derived by two scenarios depending on the cosmetics usage of Koreans. The first scenario is the combined use of representative cosmetics and oral care products. The second scenario is the combined use of rinse-off products of cleansing, deodorants, coloring products, and oral care products. SEDs have been calculated as 0.14337 mg/kg bw/day for the first scenario and 0.04733 mg/kg bw/day for the second scenario. As a result, margin of safety (MOS) for the first and second scenarios was estimated to 84 and 253.5, respectively. Based on these results, exposure of TCS contained in rinse-off products, deodorants, and coloring products would not pose a significant health risk when it is used up to 0.3%.

• 천문학회보
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• 제44권1호
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• pp.37.1-37.1
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• 2019

The faint quasars with M1450 > -24 mag are known to hold the key to the determination of the ultraviolet emissivity for the cosmic reionization. But only a few have been identified so far because of the limitations on the survey data. Here we present the first results of the z ~ 5 faint quasar survey with the Infrared Medium-deep Survey (IMS), which covers ${\sim}100deg^2$ areas in J band to the depths of $J_{AB}$ ~ 23 mag. To improve selection methods, the medium-band follow-up imaging has been carried out using the SED camera for QUasars in Early uNiverse (SQUEAN) on the Otto Struve 2.1 m Telescope. The optical spectra of the candidates were obtained with 8 m class telescopes. We newly discovered 10 quasars with -25 < $M_{1450}$ < -23 at z ~ 5, among which three have been missed in a previous survey using the same optical data over the same area, implying the necessity for improvements in high-redshift faint quasar selection. We derived photometric redshifts from the medium-band data and found that they have high accuracies of ${\langle}{\mid}{\Delta}z{\mid}/(1+z){\rangle}=0.016$. The medium-band-based approach allows us to rule out many of the interlopers that contaminate ${\geq}20%$ of the broadband-selected quasar candidates. These results suggest that the medium-band-based approach is a powerful way to identify z ~ 5 quasars and measure their redshifts at high accuracy (1%-2%). It is also a cost-effective way to understand the contribution of quasars to the cosmic reionization history.

• Toxicological Research
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• 제35권2호
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• pp.131-136
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• 2019

Ethylhexyl dimethyl para-aminobenzoic acid (PABA) is an oily yellow liquid derivative of water-soluble PABA commonly used in sunscreen. Ethylhexyl dimethyl PABA is widely used as an ingredient in many cosmetics at an average concentration of 1.25% (0.5-2.0%) in Korea. Previous studies, including those involving animals, have demonstrated that ethylhexyl dimethyl PABA is toxic to the following four organs: testis, epididymis, spleen, and liver. In addition, experiments using human keratinocytes found that ethylhexyl dimethyl PABA inhibits cell growth and DNA synthesis at low concentrations, and halted the cell cycle of MM96L cells (human melanoma cell line) at the G1 phase. Despite limited clinical data in humans, many studies have confirmed increased mutagenicity of ethylhexyl dimethyl PABA following exposure to sunlight, which suggests that this molecule is likely to contribute to onset of sun-induced cancer despite protecting the skin through absorption of UVB. For risk assessment, the no observed adverse effect level (NOAEL) chosen was 100 mg/kg bw/day in a 4 weeks oral toxicity study. Systemic exposure dosage (SED) was 0.588 mg/kg bw/day for maximum use of ethylhexyl dimethyl PABA in cosmetics. Based on the risk assessment and exposure scenarios conducted in this study, the margin of safety (MOS) was calculated to be 180.18 for a sunscreen containing 8% ethylhexyl dimethyl PABA, which is the maximum level allowed by the relevant domestic authorities.

• Safety and Health at Work
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• 제12권2호
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• pp.244-248
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• 2021

Background: Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure. Methods: A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test. Results: Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m², were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively. Conclusion: Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.

• 천문학회보
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• 제46권2호
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• pp.49.1-49.1
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• 2021

We carried out simultaneous monitoring observations of five maser lines, H₂O (22 GHz), SiO 𝝊 =1, 2, J =1-0 (43.1, 42.8 GHz), and SiO 𝝊 =1, J=2-1, J =3-2 (86.2, 129.3 GHz), toward the Mira variable star WX Serpentis with the 21-m antennas of the Korean VLBI Network (KVN) in 2009-2021 (~12 years). Most spectra of the H₂O maser are well separated into two parts of two blue- and one redshifted features within ± 10 km s-1 of the stellar velocity. All detected SiO masers are generally concentrated within ± 5 km s-1 of the stellar velocity, and sometimes appear split into two components. Overall, the profiles of SiO and H₂O masers detected in WX Serpentis illustrate typical characteristics of the Mira variable. In addition, flux variations of both SiO and H₂O masers are well correlated with the optical light curve of the central star, showing a phase lag of ~ 0.1 for SiO masers and ~ 0.2 for H₂O maser. This phenomenon is considered to be the direct effect of propagating shock waves generated by the stellar pulsation, because SiO and H₂O masers are sequentially distributed at different positions with respect to the central star. In addition, we analyzed long-term trends and characteristics of maser velocities, maser ratio, and the velocity extents (the full width at zero power; FWZP). We also investigated a spectral energy distribution (SED) ranging from 1.2 to 240 ㎛ obtained using several infrared data: 2MASS, WISE, IRAS, ISO, COBE DIBRE, RAFGL, and AKARI (IRC and FIS). From the IRAS LRS and ISO SWS spectra of this star, we identified 9.7 and 12 ㎛ silicate emission features consistent with the SE6 spectrum model, corresponding to the typical AGB phase.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2022년도 추계학술대회
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• pp.164-167
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• 2022

표 기계독해에서는 도메인에 따라 언어모형에 필요한 지식이나 표의 구조적인 형태가 변화하면서 텍스트 데이터에 비해서 더 큰 성능 하락을 보인다. 본 논문에서는 표 기계독해에서 이러한 도메인의 변화에 강건한 사전학습 표 언어 모형 구축을 위한 의미있는 표 데이터 선별을 통한 사전학습 데이터 구축 방법과 적대적인 학습 방법을 제안한다. 추출한 표 데이터에서 구조적인 정보가 없이 웹 문서의 장식을 위해 사용되는 표 데이터 검출을 위해 Heuristic을 통한 규칙을 정의하여 HEAD 데이터를 식별하고 표 데이터를 선별하는 방법을 적용했으며, 구조적인 정보를 가지는 일반적인 표 데이터와 엔티티에 대한 지식 정보를 가지는 인포박스 데이터간의 적대적 학습 방법을 적용했다. 기존의 정제되지 않는 데이터로 학습했을 때와 비교하여 데이터를 정제하였을 때, KorQuAD 표 데이터에서 F1 3.45, EM 4.14가 증가하였으며, Spec 표 질의응답 데이터에서 정제하지 않았을 때와 비교하여 F1 19.38, EM 4.22가 증가한 성능을 보였다.

• 운동영양학회지
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• 제16권2호
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• pp.93-100
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• 2012

Alzheimer's disease (AD) is the most common cause of dementia in adults. Microtubule associated protein tau is abnormally phosphorylated in AD and aggregates as paired helical filaments (PHFs) in neurofibrillary tangles (NFTs). NFTs are the most common intraneuronal inclusion in the brains of patients with AD and have been implicated in mediating neuronal cell death and cognitive deficit. Aberrant phosphorylation of tau is an early pathological event in AD, but the underlying mechanisms are unclear. MAP kinases are a family of Serine/Threonine (Ser/Thr) kinases that involved hyper - phosphorylation of tau in AD. The purpose of this study was to investigate the effect of treadmill exercise on phosphorylation of tau level and activation of MAPKs including JNK, ERK, p38-MAPK. To address this, Tg mouse model of AD, Tg-NSE/hTau 23, which expresses human tau 23 in the brain, was chosen. Animals were subjected to treadmill exercise for 12 weeks from 24 months of age. Treadmill exercise in Tg group improved cognitive function compared with Tg-SED group in watermaze test. In addition, treadmill exercised Tg mice significantly reduced the activation of JNK54/46, p38-MAPK and tau (Ser404, Ser202, Thr231), and increased activation of ERK44/42 in cerebral cortex. These results suggest that treadmill exercise may provide a therapeutic potential to alleviate the tau pathology like AD.