• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.371-374
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• 2005

We accomplished optimization for pump and treat (P&T) designs in consideration of degradation processes such as retardation and biodegradation, which are significant for contaminant fate in hydrogeology. For more desirable remediation, optimal pumping duration and minimum pumping rate constraint problems are studied. After a specific P&T duration, it replaces the P&T with the enhanced natural attenuation (ENA), which induces aerobic biodegradation by maintaining oxygen concentration. The design in this strategy carries out the optimization for the number and locations of oxygen injection wells.

• 한국농공학회지
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• 제41권1호
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• pp.39-51
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• 1999

This study has an object to evaluate runoff characteristics with ILLUDAS model and SWMM owing to each rainfall distribution type of Huff's quartile and each rainfall duration time of 30 ,60, 120 and 180 minutes. As a result of this study, Type-Ⅰ Extreme (TIE) rainfall distribution pattern with Huff's 2nd quartile is adequate for Cheju volcanic island . To decide optimal rain fall duration , time of concentration and critical duration should be compared and analyzed each other. In this study, 30 and 120 miniutes were suggeste to iptiaml duration time of A and B study basins. It is concluded that the magnitude of peak runoff discharge is maximum with Huff's 4th quartile, and that of total runoff volume is maximum with Huff's 4th quartile for ILLUDAS model and with Huff's 1st quartile for SWMM. As rainfall duration time increasing is increasing . Also in case of total runoff volume, volumen by SWMM is less than by ILLUDAS model as to variation ratio of total runoff volume in A and B study basin. Therefore, the resulots of this study canb e sued as basic data in determining adequate rainfoal duration time and rainfall distribution type and used for urban drainage systems analysis and design at small urbanization catchment is Cheju volcanic island.

• 한국농공학회논문집
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• 제54권5호
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• pp.123-128
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• 2012

For optimal reservoir operation and management, there are essential elements including water supply in agricultural reservoir and demand in irrigation district. To estimate agricultural water demand and supply, many factors such as weather, crops, soil, growing conditions cultivation method and the watershed/irrigation area should be considered, however, there are occurred water supply impossible duration under the influence of the variability and uncertainty of meteorological and hydrological phenomenon. Focusing on agricultural reservoir, amount and tendency of agricultural water supply and demand shows seasonally/regionally different patterns. Through the analysis of deviation and changes in the timing of the two elements, duration in excess of water supply can be identified quantitatively. Here, we introduce an approach to assessment of irrigation vulnerable duration for effective management of agricultural reservoir using time dependent change analysis of residual water supply and irrigation water requirements. Irrigation vulnerable duration has been determined through the comparison of water supply in agricultural reservoir and demand in irrigation district based on the water budget analysis, therefore can be used as an improved and basis data for the effective and intensive water management.

• 동굴
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• 제71호
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• pp.1-4
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• 2006

Chloromethylnaphthalene is a valuable compound for obtaining of the plant growing stimulator - -napthylacetic acid. Chloromethylation of naphthalene by paraformaldehyde in the presence of glacial acetic acid, phosphoric and hydrochloric acids at temperature 80 - 85C and duration - 6 hours the -chloromethylnaphthalene yield was 55-57%. Using Box-Wilson method for mathematical planning of experiment carried out optimization of its synthesis for purpose increasing -chloromethylnaphthalene yield. Preliminary, one - factor experiments were carried out for selecting independence main parameters influencing on the synthesis. A full factor experiment of 23 with extended matrix of planning was used for optimization. Aiming to increase the -chloromethylnaphthalene yield, the obtained mathematical model was used for program of sharp raising on the reply surface. The received optimal conditions for the -chloromethylnaphthalene synthesis were selected as following: molar ratio of naphthalene parapfsormaldehyde of 1 : 2 temperature - 105C duration of the reaction - 3 hours. The yield of -chloromethylnaphthalene under these optimal conditions was 75%.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.36-37
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• 2004

$\alpha$-Chloromethylnaphthalene is a valuable compound for obtaining of the plant growing stimulator - $\alpha$-napthylacetic acid. Chloromethylation of naphthalene by paraformaldehyde in the presence of glacial acetic acid, phosphoric and hydrochloric acids at temperature 80-85$^{\circ}C$ and duration - 6 hours the $\alpha$-chloromethyl-naphthalene yield was 55-57%. Using Box-Wilson method for mathematical planning of experiment carried out optimization of its synthesis for purpose increasing $\alpha$-chloromethylnaphthalene yield. Preliminary, one - factor experiments were carried out for selecting independence main parameters influencing on the synthesis. A full factor experiment of 2$^3$with extended matrix of planning was used for optimization. Aiming to increase the $\alpha$-chloromethylnaphthalene yield, the obtained mathematical model was used for program of sharp raising on the reply surface. The received optimal conditions for the $\alpha$-chloromethylnaphthalene synthesis were selected as following: molar ratio of naphthalene - parapfsormaldehyde of 1 : 2; temperature -105$^{\circ}C$; duration of the reaction -3 hours. The yield of $\alpha$-chloromethylnaphthalene under these optimal conditions was 75 %.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1151-1155
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• 2008

This study aimed to investigate the alterations in plasma antioxidant activity after the consumption of a single oral dose of curcumin, vitamin C, and E administered individually or in combination to (i) assess possible synergies or antagonism between the antioxidants and (ii) determine the optimal composition of the antioxidant mixture such that the duration of action is prolonged to beyond that of individual antioxidants. Each antioxidant was administered to male Sprague-Dawley rats, and blood samples were drawn at different time points up to 180 min to measure the plasma total antioxidant capacity (TAC). Five antioxidant compositions (M1-M5) were evaluated to assess the possible synergies or antagonisms among them and to determine the optimal composition of the antioxidant mixture. Blood samples were collected up to 360 min post-consumption. A single oral dose of individual antioxidants significantly increased the TAC values; however, the time to reach the peak TAC value varied. Among the 5 antioxidant compositions, M2 exhibited the highest and most prolonged antioxidant effect in plasma; this was greater than the proportional sum of the effects of the individual antioxidants in the composition. This result indicates a synergistic interaction among antioxidants in the optimal composition M2.

• Safety and Health at Work
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• 제12권3호
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• pp.311-316
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• 2021

Background: The present study investigated the association between two domains of physical activity (occupational physical activity [OPA] and leisure-time physical activity [LTPA]) and sleep duration. Methods: We investigated 3,421 paid workers from the Korea National Health and Nutrition Examination Survey, 2014-2015. Sleep duration was categorized into three categories (short for less than 5 h, optimal for 5-9 h, and long for more than 9 h). OPA and LTPA were defined in terms of answers to relevant questions. Odds ratios were calculated for sleep duration according to each physical activity domain using multinomial logistic regression models. Results: There were 464 subjects (13.6%) who showed short sleep duration, and 169 subjects (4.9%) who showed long sleep duration. Prevalence of OPA and LTPA was higher in male workers than in female workers (for OPA: 3.67% and 1.76%, respectively, p = 0.0108; for LTPA: 16.14% and 6.07%, respectively, p < 0.0001). The odds ratio of OPA for long sleep duration in female workers was 3.35 (95% confidence interval, 1.37-8.21). Otherwise, LTPA was not associated with sleep duration in female paid workers, nor both physical activity domains in male paid workers. Conclusion: Female paid workers with work-related physical activity were at risk of oversleeping. These findings also suggested that physical activity has distinct associations with sleep duration according to the physical activity domains and sex.

• 정보처리학회논문지D
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• 제10D권7호
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• pp.1127-1136
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• 2003

소프트웨어 개발 초기에 개발비용, 소요 인력과 기간을 추정하는 것은 소프트웨어공학 분야의 주요한 요소이며, 어려운 문제이다. 소프트웨어 개발 소요 인력을 추정하기 위한 대부분의 모델들은 소프트웨어 요구사항 명세서로부터 측정된 기능점수를 이용하였다. 본 논문은 기능점수에 기반하여 프로젝트에 대한 가장 실제적이고 생산적인 팀 규모와 개발기간을 선택하는 지침으로 사용될 수 있는 정보를 제공하기 위해 생산성 척도와 비용 척도를 도입하였다. 소프트웨어 개발과 유지보수를 수행한 300개 프로젝트 데이터 집합을 2개의 서브 그룹인 개발 프로젝트와 유지보수 프로젝트로 분류하였다. 생산성과 비용 측도 기준에 의해 분석한 결과 작은 팀 규모와 최소한의 개발기간이 소요되었을 때, 프로젝트가 성공적으로 수행됨을 보였다. 또한, 연구 결과에 근거하여 기능점수 규모에 따른 개발팀의 규모와 개발기간을 추정할 수 있는 모델을 제안하였다. 본 제안 모델은 소프트웨어 규모에 따라 필요한 개발팀의 규모와 개발기간 평가 기준을 제공한다.

• Earthquakes and Structures
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• 제14권6호
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• pp.577-587
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• 2018

The quantitative assessment of the seismic collapse risk of a structure requires the usage of an optimal intensity measure (IM) which can adequately characterise the severity of the ground motion. Research suggests that the average spectral acceleration ($Sa_{avg}$) may be an efficient and sufficient alternate IM as compared to the more traditional first mode spectral acceleration, $Sa(T_1)$, particularly during seismic collapse risk estimation. This study primarily presents a comparative evaluation of the sufficiency of the average spectral acceleration with respect to ground motion duration, and secondarily assesses the impact of ground motion duration on collapse risk estimation. By assembling a suite of 100 historical ground motions, incremental dynamic analysis of 60 different inelastic single-degree-of-freedom (SDF) oscillators with varying periods and ductility capacities were analysed, and collapse risk estimates obtained. Linear regression models are used to comparatively quantify the sufficiency of $Sa_{avg}$ and $Sa(T_1)$ using four significant duration metrics. Results suggests that an improved sufficiency may exist for $Sa_{avg}$ when the period of the SDF system increases, particularly beyond 0.5, as compare to $Sa(T_1)$. In reference to the ground motion duration measures, results indicated that the sufficiency of $Sa_{avg}$ is more sensitive to significant duration definitions that consider almost the full wave train of an accelerogram ($SD_{a5-95}$ and $SD_{v5-95}$). In order to obtain a reduced variability of the collapse risk estimate, the 5-95% significant duration metric defined using the Arias integral ($SD_{a5-95}$) should be used for seismic collapse risk estimation in conjunction with $Sa_{avg}$.

• 지역사회간호학회지
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• 제29권4호
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• pp.440-449
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• 2018

Purpose: The purpose of this study is to identify the dietary habits of Korean adolescents and to investigate their effects on sleep duration. Methods: This study is a secondary analysis drawn from the 2016 Korean Youth Risk Behavior Web-Based Survey (N=65,528). ANCOVA was used to determine the relationship between dietary habits and sleep duration. Ordinal logistic regression was used to find out the effects of dietary habits on sleep duration adjusted for general characteristics and behavioral characteristics. Results: The group that consumed no breakfast (AOR=0.89, p<.001) had less sufficient sleep duration than those who had breakfast 7 times per week. The group that had drunk no milk (AOR=0.88, p<.001) had less sufficient sleep duration than those who enjoyed it 5 times per week. On the contrary, the groups that had no soda drinks (AOR=1.18, p=.015), caffeine drinks (AOR=1.77, p<.001), and sweet drinks (AOR=1.25, p<.001) were more likely to have sufficient sleep duration than the groups that consumed those beverages 5 times per week. Conclusion: It is important to educate adolescents about healthy eating habits including drinks and optimal sufficient sleep duration through a multidisciplinary approach.