• Journal of Electrochemical Science and Technology
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• v.2 no.3
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• pp.131-135
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• 2011

It is, in general, believed that during the activation process, the proton conductivity increases due to wetting effect and the electrochemical resistance reduction, resulting in an increase in the fuel cell performance with time. However, until now, very scant information is available on the understanding of activation processes. In this study, dominant variables that effect on the performance increase of membrane electrode assemblies (MEAs) during the activation process were investigated. Wetting, pore restructuring and active metal utilization were analyzed systematically. Unexpectedly, the changes for both ohmic and reaction resistance characterized by the electrochemical impedance spectroscopy (EIS) after initial wetting process were much smaller when considering the degree of cell performance increases. However, the EIS spectra represents that the pore opening of electrode turns into gas transportable structure more easily. The increase in the performance with activation cycles was also investigated in a view of active metals. Though the particle size was grown, the number of effective active sites might be exposed more. The impurity removal and catalytic activity enhancement measured by cyclic voltammetry (CV) could be a strong evident. The results and analysis revealed that, not merely wetting of membrane but also restructuring of electrodeand catalytic activity increase are important factors for the fast and efficient activation of the polymer electrolyte fuel cells.

• Archives of design research
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• v.17 no.1
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• pp.63-76
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• 2004

Although information design principles had originated from the graphic design field including publishing design in 1970s, information design have taken one of the most important positions in multimedia design fields as the present since Richard Saul Wurmn started his researches on information design and its practical application on internet environments. However, relatively little researches have been performed for building identity of information design in multimedia design fields so far and moreover in some cases, information design is likely to be narrowly viewed as 'the representation of a piece of information and its visualization' which was defined in traditional graphic design field. This research circumstance leads the study to investigate characteristics of information design in current multimedia design with contingent perspective which is compared to the traditional information design. The study results suggest 5 characteristics of information design including 'suggesting context & finding out information hierarchy', 'access of integrated consideration & share of information control', 'using of multi-dimensional media & content first', 'stabilization of information quality & combinational understanding of meaning', 'bilateral information representation & user's knowledge expansion'. Future researches, based on the results of the study, are expected to be expanded to a degree with argument for inter-dependent and/or exclusive characteristics of adjacent fields of information design such as interface design, interaction design and experience design.

• Journal of Practical Engineering Education
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• v.8 no.2
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• pp.83-89
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• 2016

Flip-learning enables an effective teaching and learning in accordance with the deepening degree of engineering education as a framework that enables learning according to the individual differences of the theoretical aspects, and solving real problems and practice of the learner-centered education through the application of this. The subject of basic fluid power practice which is used in various industries requiring factory automation aims at understanding of the composition and operating principles of pneumatic components and programming of electric sequential circuits, building the design ability of pneumatic system. This subject goes by 3 hour classes with theory and practice side by side. So it has not enough time to instruct students various contents related in this subject. In this study, the instructional design was performed according to the KOREATECH (Korea University of Technology and Education) flip-learning basic model for the effective teaching of 'Basic Fluid Power Practice' in basic engineering practice courses,. And the effectiveness of flip-learning is analyzed through the students survey after performing classes.

• Bulletin of the Korean Chemical Society
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• v.22 no.5
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• pp.514-518
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• 2001

We have explored the importance of two ATP binding domains of Hsp104 protein in protection of yeast cells from cadmium exposure. In the previous study we have discovered that the presence of two ATP binding sites was essential in providing heat sh ock protection as well as rescuing cells from oxidative stress. In this paper we first report wild type cell with functional hsp104 gene is more resistant to cadmium stress than hsp104-deleted mutant cell, judging from decrease in survival rates as a result of cadmium exposure. In order to demonstrate functional role of two ATP binding sites in cadmium defense, we have transformed both wild type (SP1) and hyperactivated ras mutant (IR2.5) strains with several plasmids differing in the presence of ATP binding sites. When an extra copy of functional hsp104 gene with both ATP binding sites was overexpressed with GPD-promoter, cells showed increased survival rate against cadmium stress than mutants with ATP binding sites changed. The degree of protection in the presence of two ATP binding sites was similarly observed in ira2-deleted hyperactivated ras mutant, which was more sensitive to oxidative stress than wild type cell. We have concluded that the greater sensitivity to cadmium stress in the absence of two ATP binding sites is attributed to the higher concentration of reactive oxygen species (ROS) produced by cadmium exposure based on the fluorescence tests. These findings, taken all together, imply that the mechanism by which cadmium put forth toxic effects may be closely associated with the oxidative stress, which is regulated independently of the Ras-cAMP pathway. Our study provides a better understanding of cadmium defense itself and cross-talks between oxidative stress and metal stress, which can be applied to control human diseases due to similar toxic environments.

• Nuclear Engineering and Technology
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• v.42 no.4
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• pp.339-364
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• 2010

Following a joint OECD/NEA-IAEA-sponsored meeting to define the current role and future perspectives of the application of Computational Fluid Dynamics (CFD) to nuclear reactor safety problems, three Writing Groups were created, under the auspices of the NEA working group WGAMA, to produce state-of-the-art reports on different aspects of the subject. The work of the second group, WG2, was to document the existing assessment databases for CFD simulation in the context of Nuclear Reactor Safety (NRS) analysis, to gain a measure of the degree of quality and trust in CFD as a numerical analysis tool, and to take initiatives to extend the existing databases. The group worked over the period of 2003-2007 and produced a final state-of-the-art report. The present paper summarises the material gathered during the study, illustrating the points with a few highlights. A total of 22 safety issues were identified for which the application of CFD was considered to potentially bring real benefits in terms of better understanding and increased safety. A list of the existing databases was drawn up and synthesised, both from the nuclear area and from other parallel, non-nuclear, industrial activities. The gaps in the technology base were also identified and discussed. In order to initiate new ways of bringing experimentalists and numerical analysts together, an international workshop -- CFD4NRS (the first in a series) -- was organised, a new blind benchmark activity was set up based on turbulent mixing in T-junctions, and a Wiki-type web portal was created to offer online access to the material put together by the group giving the reader the opportunity to update and extend the contents to keep the information source topical and dynamic.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.142-142
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• 2023

Humans inevitably and continuously produce wastewater in daily life worldwide. To decrease the degradation of river water bodies and aquatic ecosystem therein, humans have built systems at different scales to collect, drain, and treat household-produced wastewater. Particularly, municipal wastewater treatment plants (WWTPs) with centralized controls have played a key role in reducing loads of nutrients in domestic wastewater for the last few decades. Notwithstanding such contributions, impaired rivers regarding water quality and habitat integrity still exist at the whole river basin scale. It is highly attributable to the absence of dilution capacity of receiving streams and/or the accumulation of the pollutant loads along flow paths. To improve the perspective for individual WWTPs assessment, the first crucial step is to achieve systematic understanding on spatial distribution characteristics of all WWTPs together in a given river basin. By taking the initiative, our former study showed spatial hierarchical distributions of WWTPs in three large urbanized river basins in Germany. In this study, we uncover how municipal WWTPs in the contiguous United States are distributed along river networks in a give river basin. The extended spatial scope allows to deal with wide ranges in geomorphological attributes, hydro-climatic conditions, and socio-economic status. Furthermore, we identify the relation of the findings with multiple factors related to human activities, such as the spatial distribution of human settlements, the degree of economy development, and the fraction of communities served by WWTPs. Generalizable patterns found in this study are expected to contribute to establishing viable management plans for recent water-environmental challenges caused by WWTP-discharges to river water bodies.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.243-249
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• 2013

Objectives: This study assessed the status of domestic industrial hygiene laboratories using data from on-site investigation for revision of quality control systems in 2012-2013. Methods: The target laboratories were 60 industrial hygiene laboratories chosen by random selection and nationwide distribution which had participated in on-site investigations for revision of quality control systems from March 2012 to August 2013. The investigation was performed on-site following standard quality control procedures. The score between each group was compared using Mann-Whitney and Kruskal-Wallis tests, and the correlation between analytical career, sex, academic major of analyst and score of analytical performance was expressed as Spearman's rank correlation coefficient. Results: The assessment revealed that the items to be improved, in sequence, were effort at staff training (score 65.5), ability to calculate data (score 73.4), establishment of internal quality control guidelines (score 75.7), laboratory facilities (score 77.1), degree of understanding and skill at gas chromatography (score 77.1). Analysis performance showed a positive correlation with career of analyst (r=0.56, p<0.01). Conclusions: The practice of on-site investigation for quality control systems showed the current status of industrial hygiene laboratories in the first trial. There were many laboratories which needed improvement and development of analytical systems. This assessment can provide information for the systematic operation and improvement of facilities at each laboratory. Further practice of this investigation will lead to a proficiency testing and accreditation system for autonomous quality control as is the practice in many countries, rather than mandatory practice by legal regulation.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.3
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• pp.9-17
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• 2015

After its inception in 1994, the Journal of the Microelectronics and Packaging Society has continued to make significant strides in the number and quality of publications within its field. The interest in the microelectronics and packaging research has become more critical as consumer electronic products continue its increasing trend towards thinner and lighter devices that tests the boundaries of electronic devices. This study utilizes social network analysis of all published literature in the Journal for the past 22 years. Using the keywords and abstracts available within each individual article, the publications within the Journal has focused on major topics covering (1) flip chip, (2) reliability, (3) Cu, (4) IMC (intermetallic compounds), and (5) thin film. Using the social network relationship between keywords within articles, flip chip was closely associated with reliability, BGA (ball grid array), contact resistance, electromigration in many of the published research works within the Journal. From the centrality analysis, it was found that flip chip, reliability, Cu, thin film, IMC, and RF (radio frequency) to have a high degree of centrality suggesting these key areas of research have relatively high connectivity with other research topics within the Journal and is central to many of the research fields within the micro-electronics and packaging area. The cohesiveness analysis showed research clustering of five major cohesive sub-groups and was mapped to better understand the major area of research within this field. Research within the field of micro-electronics and packaging converges many disciplines of science and engineering. The continued evolution within this field requires an understanding of the rapidly changing industry environment and the consumer needs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.4
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• pp.626-629
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• 2002

In Oriental medicine, Five Mental is a concept for understanding of man's mental structure. Spirit and body is inseparable relation in Oriental Medicine. Function of spirit and body is regarded as one in Oriental Medical physiology. Spirit is the essence of a function which an organism reveal, and it is regarded in the same with life. For this reason, identification spirit with life is special feature of Oriental Medicine. In Confucianism, Li(理) refers to nature's discipline, which everything under the sun shares. It is similar to the concept of Shin(神) in a broad sense and Sung(性) is similar to that of Shin(神) in a narrow sense. Confucianism's principle is similar to Oriental medicine's, in that they classify Sung(性) into Gi-Jil-Ji-Sung(氣質之性) and Bon-Yeon-Ji-Sung(本然之性), that Sung(性) acts upon man differently according to his disposition, and that materials have an effect on Shin(神)'s action. According to mind's action, there are Human mind(人心) and Moral mind(道心). Human mind(人心) is defined as a mental action of higher degree and Moral mind(道心) is conceived as a mental action related to body. It is similar to Oriental medicine's principle in which Shin(神) is classified into Hun(魂) and Beak(魄) according to its action. Yi(意) is self-control and application, and Zhi(志) is a conscious state in which basic acts towards the object are fixed regularly. Those are similar to the concepts of Oriental medicine.

• Korean Journal of Adult Nursing
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• v.12 no.4
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• pp.497-506
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• 2000

The purpose of this phenomenological study was to explore and describe the experience of people with HIV/AIDS. Three men and three women with HIV/AIDS participated in the study. They were asked open-ended and descriptive questions in order for them to talk about their experience in their own terms. Interviews were audiotaped and transcribed to maintain data integrity and to reduce perceptual bias. The transcripts were analyzed by the Colaizzi method. Member checks from the participants were used to validate the emergent themes. Seven themes emerged from the analysis. 1. People with HIV/AIDS have a strong impact and emotional reaction when receiving positive HIV test results. 2. All people with HIV/AIDS attempt to conceal HIV infection because of fear of stigma or rejection. 3. After the initial brief traumatic reaction to HIV/AIDS diagnosis, all participants feel lonely because they had no one to express or share their own experiences. 4. People with HIV/AIDS reflect on their life, think about the death and dying process and they become depressed. 5. Most participants feel that the family members who know his/her diagnosis are a big source of support. 6. According to the normativeness of infection route of HIV, the degree of guilty feeling differs among participants. 7. Although all participants think medication is a lifeline, the adherence to medication is not maintained because of side effects, denial and concealment of HIV/AIDS. The results of this study may help nurses and other health care workers to implement more efficient nursing strategies for people with HIV/AIDS by more deeply understanding their experience.