• Membrane and Water Treatment
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• 제2권3호
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• pp.137-145
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• 2011

Membrane processes are major breakthrough for the removal of organic pollutants in water remediation. The separations of solutes depend on nature of the membranes and solutes. The separation performance depends on the nature of the solutes (i.e., molecular volume, polarity, and hydrophobicity) for the same membrane. As 4-chlorophenol is of more dipolemoment compared to 2-chlorophenol, the orientation of the molecule enables it pass through the pores of the membrane, which is of negatively charged and thus separation order follows: 2-chlorophenol > 4-chlorophenol. Hydrophobicity factor also supports the order. Addition of sodium dodecyl sulfate (SDS) to chlorophenol solution shows remarkable increase in separation performance of the membrane. The improvement in separation is 1.8 and 1.5 times for 4- and 2- chlorophenol consecutively in case of 0.0082 M SDS (1cmc = 0.0082 M) in the solution. 4-chlorophenol has better attachment tendency with SDS because of its relatively more hydrophobic nature and thus reflects in performance i.e. the separation performance of 4-chlorophenol with SDS through the membrane is better compared to 2-chlorophenol.

• 한국간호교육학회지
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• 제26권1호
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• pp.5-15
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• 2020

Purpose: This paper is a critical review of descriptive phenomenological methodology in Korean nursing research. We propose constructive suggestions for the improvement of descriptive phenomenological methodology in light of Husserl's phenomenological approaches. Methods: Using the key words of 'phenomenology,' 'experience,' and 'nursing,' we identify and analyze 64 Korean empirical phenomenological studies (selected from 282 studies) published in 14 Korean nursing journals from 2005 to 2018. The PubMed and the Korea Citation Index were used to identify the studies. Results: Our analysis shows that all the reviewed articles used Giorgi's or Colaizzi's scientific phenomenological methodology, without critical attention to Husserl's philosophical phenomenological principles. Conclusions: The use of scientific phenomenology in nursing research, which originated in North America, has become a global phenomenon, and Korean phenomenological nursing research has faithfully followed this scholarly trend. This paper argues that greater integration of Husserlian phenomenological principles into scientific phenomenological methodology in nursing research, such as participant-centered bracketing and eidetic reduction, is needed to ensure that scientific phenomenology lives up to its promise as a research methodology.

• Journal of Microbiology and Biotechnology
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• 제19권11호
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• pp.1333-1341
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• 2009

Haematococcus pluvial is, a green alga, accumulates astaxanthin (3,3'-dihydroxy-$\beta$,$\beta$'-carotene-4,4'-dione) upto 2-3% on a dry weight basis. In the present study, identification of carotenoids from Haematococcus cyst cell extract by HPLC and LC-MS (APCI) and their antioxidant properties were evaluated in in vitro model systems. The extract exhibited 89% and 78% antioxidant activities in the $\beta$-carotene linoleate model and the hydroxyl radical scavenging model, at 9 ppm of total carotenoid, respectively. The extract also showed 80%, 85%, and 79% antioxidant activities against lipid peroxidation in the kidney, brain, and liver of rats. Low-density lipoprotein oxidation induced by $Cu^{2+}$ ions was also protected (45%, 64%, and 75%) by the extract in a dose-dependent manner with different carotenoid levels. Thiobarbituric acid reactive substances concentration in the blood, liver, and kidney of rats were also significantly (p<0.005) decreased in H. pluvialis-treated rats. The potent antioxidant activity is attributable to various carotenoids present in the extract.

• Structural Engineering and Mechanics
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• 제66권3호
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• pp.399-409
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• 2018

This paper demonstrates the potential application of machine learning algorithms for approximate prediction of the load and deflection capacities of the novel type of Laced Steel Concrete-Composite (LSCC) beams proposed by Anandavalli et al. (Engineering Structures 2012). Initially, global and local responses measured on LSCC beam specimen in an experiment are used to validate nonlinear FE model of the LSCC beams. The data for the machine learning algorithms is then generated using validated FE model for a range of values of the identified sensitive parameters. The performance of four well-known machine learning algorithms, viz., Support Vector Regression (SVR), Minimax Probability Machine Regression (MPMR), Relevance Vector Machine (RVM) and Multigene Genetic Programing (MGGP) for the approximate estimation of the load and deflection capacities are compared in terms of well-defined error indices. Through relative comparison of the estimated values, it is demonstrated that the algorithms explored in the present study provide a good alternative to expensive experimental testing and sophisticated numerical simulation of the response of LSCC beams. The load carrying and displacement capacity of the LSCC was predicted well by MGGP and MPMR, respectively.

• 대한산업공학회지
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• 제6권1호
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• pp.17-22
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• 1980

The performance of scientific researchers has been studied from a number of different aspects, mostly in developed countries. This paper attempted to identify salient factors influencing scientific performance at individual level in a developing country. A model describing the productivity and performance of scientific researchers was developed. Four hypotheses were derived from the model; i) the degree of diversity of a researcher will affect the degree of his scientific performance, ii) the degree of dedication will affect the degree of his performance, iii) the degree of research pressure will affect the degree of his performance, and iv) the degree of satisfaction will affect the degree of his performance. Data were collected through questionnaires responded by 48 researchers from two research organizations. The results of data analysis supported the hypotheses in part. Specifically, diversity measured by the number of research areas was related to the productivity of research reports (p<0.05); research pressure influenced the average number of research papers (p<0.05). The results of hypothesis testing of the satisfaction showed mixed directions according to the indicators. Even though the results of data analysis did not support the hypotheses unanimously, probably due to the limitation of sample size, most of the descriptive analysis indicated that the direction of hypotheses in developed countries seemed to be similar in developing country too. However, more research efforts are needed to verify the research findings of developed countries in developing countries.

• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.313-320
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• 2017

Price fluctuation contract is imperative and of paramount essence in the construction industry as it provides adequate relief and cushioning for changes in the prices of input resources during construction. As a result, several methods have been devised to better help in arriving at fair recompense in the event of price chang es. However, stakeholders often appear not to be satisfied with the existing methods of fluctuation evaluation, ostensibly because of the challenges associated with them. The aim of this study was to identify the challenges to usage of building construction cost indices in Ghana. Data was gathered from contractors and quantity surveying firms. The study utilized survey questionnaire approach to elicit responses from the contractors and the consultants. Data gathered was analyzed scientifically, using the Relative Importance Index (RII) to rank the problems associated with the existing methods. The findings revealed the following among others; late release of data; inadequate recovery of costs; and work items of interest not included in the published indices as the main challenges of the existing methods. This study will provide useful lessons for policy makers and practitioners in decision making towards the usage and improvement of available indices.

• 한국초등과학교육학회지:초등과학교육
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• 제38권1호
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• pp.16-30
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• 2019

This study aimed to develop and apply the process-focused assessment, and verify the assessment's effectiveness for improving scientific communication skills in elementary science learning. To achieve the aims of this study, the unit "Action of Electricity" in elementary science text book for 5-6th students was selected, and then 13 process-focused assessments were developed to improve scientific communication skills. 119 elementary school students in 6th grade participated in this research. it was performed to compare between 60 students on the general assessment and 59 students on the process-focused assessment in the results of achievement levels on scientific concept and scientific communication skills. The results were as follows: First, this study showed that process-focused assessment had higher educational effectiveness in specific area of scientific communication skills than the general assessment. Second, the process-focused assessment can help to form students' scientific concepts as the general assessment. Furthermore, the process-focused assessment group was more effective at reducing the non-scientific concept than the general assessment.

• 대한지구과학교육학회지
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• 제8권3호
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• pp.367-377
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• 2015

The purpose of this study was to see the influences of POE science class that emphasizes explanation on science research ability, motivation of science class as well as scientific attitude of elementary students. The results drawn from this analysis were as below. Firstly, positive relationship was found between science research ability and POE science class was shown among research group. This shows that science research ability was improved as POE science class encouraged the research activities of students. It indicates that POE science class emphasizing explanation is effective in improving science research ability of students. Secondly, positive relationship was found between motivation of science class and POE science class among research group and this means that POE science class that emphasizes explanation stimulates intellectual curiosity of students and improves their attitude by actively promoting research activities. Thirdly, there was a positive relationship between scientific attitude and POE science class among research group. This presents that POE science class emphasizing explanation is effective in improving students' attitude toward science by promoting research activities. Above results show that POE science class emphasizing explanation is highly effective for elementary students. It is considered that scientific writing, discussion and debate classes have positive influences on research ability, motivation of science class and scientific attitude of elementary students. Thus, it is needed to apply POE science class to current science class as it can promote wider scientific activities among students.

• 한국초등과학교육학회지:초등과학교육
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• 제25권2호
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• pp.179-190
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• 2006

While most previous studies have developed educational programs for science gifted children and have analyzed the differences between science gifted children and ordinary children using quantitative research methods, few have investigated the differences among the science gifted, especially in terms of the scientific thinking process. The present study was conducted to explore the thinking characteristics of the elementary science gifted according to the three scientific thinking process types during the scientific problem solving process. The study resulted in the collected of quantitative and qualitative data through tests and an interview with questions and scientific problems which required the use of one of the three scientific thinking processes. Ten elementary science gifted children served as interviewees. Two types as an opistemological basis for solving the problems are revealed on inductive thinking problems. Three types are on abductive thinking, and Three or Four types are on deductive. The results are expected to have an influence on the teaching and the evaluation of the elementary science gifted.

• 보존과학연구
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• 통권24호
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• pp.153-167
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• 2003

We performed nuclear DNA typing and mitochondrial DNA sequencing analysis based on PCR from an ancient Korean remainsexcavated from Siheung in Korea. 7 bones were collected and partially STR(short tandem repeat) systems, Sex determination Amelogenin kit(Promega co, USA), were used in this study. Mitochondrial DNAs were also amplified and sequenced by ABI 310 DNA sequencer. We know that sample no. 2 and no. 3 were females and also sample no. 2 and no.7 possessed the same maternal inheritance by mitochondrial DNA sequencing results. Throughout this research, the mitochondrial DNA sequencing of human in the middle of Joseon Dynasty in Korea is obtained. In addition, this finding will be an important foundation for the future research.