• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.863-869
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• 2006

The behavior of submerged membrane bioreactor (SMBR) filtration systems utilizing rapid air backpulsing as a cleaning technique to remove reversible foulants was investigated using a genetic algorithm (GA). A customized genetic algorithm with suitable genetic operators was used to generate optimal time profiles. From experiments utilizing short and long periods of forward and reverse filtration, various experimental process parameters were determined. The GA indicated that the optimal values for the net flux fell between 263-270 LMH when the forward filtration time ($t_f$) was 30-37 s and the backward filtration time ($t_b$) was 0.19-0.27 s. The experimental data confirmed the optimal backpulse duration and frequency that maximized the net flux, which represented a four-fold improvement in 24-h backpulsing experiments compared with the absence of backpulsing. Consequently, the identification of a region of feasible parameters and nonlinear flux optimization were both successfully performed by the genetic algorithm, meaning the genetic algorithm-based optimization proved to be useful for solving SMBR flux optimization problems.

• Current Research on Agriculture and Life Sciences
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• v.12
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• pp.35-49
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• 1994

The Purpose of this study was to establish the belter residential environment in Apt. complex. In this study, the management consciousness of exterior space and the degree of satisfaction were investigated and analyzed on the GI-SAN Apt. complex in Taegu city. The data were obtained through the questionnaire survey about the exterior space of Apt. complex and analyzed by the SPSS/PC. The results of this analysis are as follow; The result of the image analysis were the cleanness factor and the arrangement factor, which have great influenced in residents image of exterior space. The dissatisfaction source of the management conditions were owing to the lake of management techniques and the discord of residents. The subject of management in the residents consciousness was the management office. In additionally, the management form by the residents were highly showed the cleaning and weeding. The main issues of their dissatisfaction about the exterior space was the lake of size, quantity of plants and rest space. The place of the most demand on management was investigated the children playground which was regarded to be the most damaged.

• Plant Journal
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• v.11 no.4
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• pp.38-46
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• 2015

중유를 연소하는 D 발전소 탈황설비는 운전시간의 경과에 따라 흡수탑 중간층에 석고가 쌓이고 가스분사 파이프 내에 경질석고 스케일이 부착됨으로써 발전설비 및 탈황설비의 정상적인 운전이 어렵게 된다. 흡수탑 내부에 발생된 스케일을 제거하지 않을 경우에는 탈황효율의 저하에 따른 SO2 배출농도의 증가로 발전가능 최대출력의 하향조정이 발생되고 나아가 발전정지를 초래한다. 스케일 제거를 위한 탈황설비 세정은 발전가능 최대출력의 하향조정이 발생하는 시점으로 결정할 수 있다. 본 연구에서는 탈황설비의 운전 자료를 분석하여 발전가능 최대출력의 하향조정이 발생되기 6주 전은 탈황설비 출구 SO2 농도값이 130ppm을 초과하고 동시에 흡수탑 차압은 380mmH2O을 초과하며, 직전 흡수탑 세정 이후 44주가 경과된 시점이 됨을 확인하였다. 그리고 흡수탑의 세정시기는 세정준비기간 6주와 발전가능 최대출력 하향이 발생되기 6주 전까지의 운전경과일수 44주를 더하여 직전 세정시점으로부터 50주가 경과된 시점임을 예측하였다.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.37-46
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• 2004

A performance analysis for newly being considered electric rail car office has been made in this study. The major purpose is to examine a proposed design in terms of its capacity and the proposed number of travels (82-84) per day. For this study we first examined the overall system configuration with detailed operational processes of cleaning and inspection. We then developed a simulation model using ARENA and designed input data from 12 selected factors and their interaction effects. A simulation run for each treatment combination of $L_{16}(2^{15})$ orthogonal array was run and 20 batch means were obtained. Through careful analyses of the results obtained, we drew a diversity of suggestions including the best factor level combination. Our confirmation experiments at the optimal level combination further validate the possibility of 82 runs and the consistency in the results.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.3
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• pp.607-615
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• 2012

The aim of the study is to estimate the management costs of apartments by the types of heating systems(individual, central, district heating system). Multiple regression analysis was adapted and the used data are derived from 128 apartment complexes in Daegeon-si. The results are as follows; first, the management cost is decreased as a size of apartment is larger, second, the costs of general maintenance, security and repairing of buildings are lower in individual heating system. however, there is no significant differences in cleaning costs by the types of heating systems.

• Child Health Nursing Research
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• v.11 no.3
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• pp.273-281
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• 2005

Purposes: The purposes of this study were to evaluate parent satisfaction with inpatient hospital services in children's hospitals and to identify variables related to parent satisfaction. Method: A descriptive correlation study was conducted. Parents of 165 children who were inpatients in two children's hospitals participated in the study. Data were collected using structured questionnaire at the time of discharge. For statistical analysis, t-test, ANOVA, and Pearson correlation analysis were used. Results: The highest parent satisfaction domain was nursing service, and the lowest parent satisfaction domain was hospital service and accommodations. Parents were less likely to be satisfied with hospital facilities, equipment, noise and cleaning and less likely to be satisfied with the lack of information they received and with the lack of communication with health care professionals. Parents with longer length of stay and with older children reported higher satisfaction than their counterparts. Moreover, parent satisfaction was related to their intention to revisit and related to intention to recommend this surveyed hospital over others. Conclusions: Efforts to improve parent satisfaction in children's hospital service and accommodation are needed to improve the quality of health care. Communication by health care professionals with parents and a partnership between parents and health care professionals are necessary to improve quality of care.

• Human Ecology Research
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• v.58 no.3
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• pp.343-356
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• 2020

This paper examines the associations of having a helper for domestic work or childcare and time spent on it by couples in South Korea. We use five waves of panel survey data from the Korean Longitudinal Survey of Women and Families (KLoWF), which allows longitudinal changes within couples over time that account for potential selection effects and unobserved heterogeneity among individuals. With fixed effects, we find outsourcing is associated with a decrease in wife's time spent on domestic work or childcare by 1 hour per week. However, the decrease is concentrated on the unemployed wife's time, but not employed wife's time. In addition, outsourcing is not a significant factor for husband's time and the husband's share of total contribution. This may be because wives are the main provider of domestic work and childcare in Korea regardless of employment status or having any helper. Due to unequal contributions between husband and wife, using outsourcing also neither alleviates the employed wife's contribution nor changes the husband's contribution. However, the results may be underestimated because there are more common and diverse types of outsourcing in a broad sense, such as going out for dinner, buying prepared food, and using dry cleaning services. We expect future studies to consider more broad types of outsourcing and examine how relations with the couple's time use at home are different by type.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.85.2-85.2
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• 2012

In this paper, we introduce the 3D modeling of the coronal magnetic field in the solar active region by extrapolating from the 2D observational data numerically. First, we introduce a nonlinear force-free field (NLFFF) extrapolation code based on the MHD-like relaxation method implementing the cleaning a numerical error for Div B proposed by Dedner et al. 2002 and the multi-grid method. We are able to reconstruct the ideal force-free field, which was introduced by Low & Lou (1990), in high accuracy and achieve the faster speed in the high-resolution calculation (512^3 grids). Next we applied our NLFFF extrapolation to the solar active region NOAA 10930. First of all, we compare the 3D NLFFF with the flare ribbons of Ca II images observed by the Solar Optical Telescope (SOT) aboard on the Hinode. As a result, it was found that the location of the two foot-points of the magnetic field lines well correspond to the flare ribbon. The result indicates that the NLFFF well capture the 3D structure of magnetic field in the flaring region. We further report the stability of the magnetic field by estimating the twist value of the field line and finally suggest the flare onset mechanism.

• Natural Product Sciences
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• v.10 no.1
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• pp.16-19
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• 2004

Triphala churna is a widely used herbal formulation that contains equal proportion of dried fruit powder of Emblica officinalis, Terminalia chebula and Terminalia belirica. In the Indian system of medicine, it is used in cleaning wounds, urinary disorders, diabetes mellitus, leprosy, constipation, eyesight promotion, piles, and as a rejuvenator. In the present study, the methanolic extract of 5 commercial Triphala was evaluated for antioxidant activity by 1,1-diphenyl-2-picryl-hydrazyl free radical scavenging method, total phenolic content by Folin-Ciocalteu method and gallic acid equivalents (GAE) by high performance thin layer chromatographic (HPTLC) method. All extracts exhibited antioxidant activity significantly. The $IC_{50}$ of the extracts ranged between $7.16\;to\;12.96\;{\mu}g/ml$. The total phenolic content of the extracts was found to be 195.3-296.4 mg of GAE/gm of GAE/gm dw. The HPTLC chromatographic data reveal that the content of GAE present in the extract was found to be $7.17-4.11\;{\mu}g/ml$. The study reveals that out of the churnas analysed, C was found to exhibit the most potent antioxidant activity. A clear correlation between $IC_{50}$ and content of GAE nor the total phenolic content could be observed. The study reveals that the consumption of Triphala would exert several beneficial effects by virtue of its antioxidant activity.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.3
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• pp.872-880
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• 2016

The purpose of this study is to find the research trends relating to flipped learning through keyword network analysis. For investigating this topic, final 100 papers (removed due to overlap in all 205 papers) were selected as subjects from the result of research databases such as RISS, DBPIA, and KISS. After keyword extraction, coding, and data cleaning, we made a 2-mode network with final 202 keywords. In order to find out the research trends, frequency analysis, social network structural property analysis based on co-keyword network modeling, and social network centrality analysis were used. Followings were the results of the research: (a) Achievement, writing, blended learning, teaching and learning model, learner centered education, cooperative leaning, and learning motivation, and self-regulated learning were found to be the most common keywords except flipped learning. (b) Density was .088, and geodesic distance was 3.150 based on keyword network type 2. (c) Teaching and learning model, blended learning, and satisfaction were centrally located and closed related to other keywords. Satisfaction, teaching and learning model blended learning, motivation, writing, communication, and achievement were playing an intermediary role among other keywords.